News

Analysis of openSUSE 11.1

noreply@blogger.com (John Roach) — Sat, 20 Jun 2009 06:59:00 +0000

Hi there. It has been some time since I wrote my own news. The reason is that lately IEEE has had these great articles that I wanted to share with you. Hoped you like them. Now back to business.

I have for long been a fan of Fedora due to its openness and available packets for almost everything and moreover flexibility of RedHat helped me through the deadly marshes of Linux world. However Fedora lacked something. That something was user friendliness. True it does have community friendliness but it lacks the friendliness which new users who have no experience with linux need. I new user to Linux must not be chocked to death with driver problems or repository clashes and dual-boot bugs.

OpenSUSE has many pros but many out-of-the-box bugs too. Let's start from the installation.

Installation : So far this was the easiest installation ever. I just emptied a partition on my windows drive and simply installed openSUSE within it. The dual-boot settings was all done automatically. For this openSUSE gets 50 points!!

First Boot : (Driver Problems) It seems that openSUSE has the same driver problems as Fedora. The moment I installed openSUSE the video card was not able to work properly (NVidia 6600 GT or TD don't remember ) I got this weird screen with lots of bright colors. The problem was resolved by taking the following steps ;

Step1: Reboot machine and write 3 at the end of the boot line in the boot menu.
Step2: In command line (init 3) write " zypper ref && zypper up " and update your system.
Step3: After update write " zypper ar http://download.nvidia.com/opensuse/11.1/ "
Step4: Write " zypper install x11-video-nvidiaG02 nvidia-gfxG02-kmp-KERNEL " where KERNEL is your supposed kernel name which you can learn from entering the following command " uname -a "
Step5: Reboot your system and cross your fingers.

By taking these five simple steps you will now be able to boot openSUSE.

Playing Around: As you can understand instead of YUM in Fedora openSUSE uses ZYPPER which is kind of funny name for package handler. The user interface is ... well... different really... it's almost like XP. ( I am using gnome... just couldn't get used to KDE ) And that's about it... If I were to give a windows user a Linux and had to choose between openSUSE and Fedora I would probably give them an openSUSE. However openSUSE lacks the Fedora repo's and such...

Hope you guys liked this peace.
I would like to hear more from you!

The Universal Handset

noreply@blogger.com (John Roach) — Thu, 11 Jun 2009 07:05:00 +0000

BY PETER KOCH, RAMJEE PRASAD // APRIL 2009

Time was when most radio sets had no software at all, and those that had any didn’t do much with it. But Joseph Mitola III, an engineer working for a company called Eâ¿¿Systems (now part of Raytheon), envisioned something very different—a mostly digital radio that could be reconfigured in fundamental ways just by changing the code running on it. In a remarkably prescient article he wrote in 1992 for the IEEE National Telesystems Conference, he dubbed it software-defined radio (SDR).

A few short years later, Mitola’s vision became reality. The mid-1990s saw the advent of military radio systems in which software controlled most of the signal processing digitally, enabling one set of electronics to work on many different frequencies and communications protocols. The first example was the U.S. military’s Speakeasy radio, which allowed units from different branches of the armed forces to communicate effectively for the first time. But the technology was costly and rather unwieldy—the first design took up racks that only a large vehicle could carry around.

In the new millennium, SDR has spread from the battlefield to the commercial arena. Wireless service providers, in particular, have begun using it in the transceivers in cellphone base stations, allowing the same hardware to handle different cellular protocols. Next, SDR will spread to sets that fit in the palm of your hand.

That will come none too soon. Today’s wireless mix is an often-turbulent alphabet soup of communication schemes: BGAN (Broadband Global Area Network), BT (Bluetooth), DECT (Digital Enhanced Cordless Telecommunication), EDGE (Enhanced Data Rates for GSM Evolution), GPRS (General Packet Radio Service), GSM (Global System for Mobile communication), IMT-A (International Mobile Telecommunications–Advanced), UMTS (Universal Mobile Telecommunications System), WiBro (Wireless Broadband), Wiâ¿¿Fi, WiMax (Worldwide Interoperability for Microwave Access), and more. A mobile software radio that could communicate in all of these ways would, of course, be invaluable.

Up until now, SDR technology worked only in applications that didn’t need to be small in size or frugal in power consumption. New technology should, however, overcome these constraints. Indeed, within

the next year or so, you can expect to see people mothballing their old cellphones in favor of new software-defined handsets. By 2015, the transition should be nearly complete.

The first software-enabled sets to crawl out of the primordial ooze of traditional analog radio were modest affairs ”Evolutionary Developments” (pdf)]. They used embedded computers only to change the output level of the RF amplifier or to shift between individual RF front ends so that one unit could cover multiple bands.

In some of today’s radios, software—often with the aid of digital hardware accelerators—does far more: It determines everything that happens to the signal after it’s converted from RF to lower frequencies and before it’s put in a form that’s suitable for your ears. In these radios, only the RF front end and the amplifier that powers the speaker still use analog components.

The next era in SDR evolution will see what some call the ideal software radio or true software radio, in which the filtering and conversion from RF to lower frequencies that’s normally accomplished in the radio’s front end will be done digitally using the appropriate software—a strategy that requires moving the analog-to-digital converter (ADC) much closer to the antenna. These radios will still require a low-noise RF amplifier, though, because it’s hard to imagine any ADC being able to pick up the micro- or even nanovolt signals generated in the antenna.

In the progression to that ideal radio, you’ll probably notice that cellphones, mobile TV sets, GPS equipment, satellite phones, PDAs, digital music players, game consoles, and their kin will begin to look less and less distinct. As with the beaks of the duck and the platypus, the evolution of such gadgetry will converge toward the most functional form—in this case a small wireless unit that allows its user always to stay connected, from anywhere and for any type of content or use.

Designing such universal gizmos will be tough, of course. Perhaps the highest hurdle will be engineering the antenna, the size of which normally depends on the frequency of operation. Indeed, it’s very difficult to make a radio with an antenna that is not a significant fraction of a wavelength in size. This dictate of physics introduces a fundamental problem, because you’d ideally like a single compact antenna to cover everything from FM reception, at roughly 100 megahertz, to satellite- and personal-network communications, which operate in the few-gigahertz range.

To cover such a large chunk of spectrum, you’d probably need a combination of something quite short, likely built into the unit’s printed-circuit board, and something relatively long, such as the wire that connects with the user’s earphones. But even if the frequency span isn’t so great, designers probably won’t be satisfied with just one antenna: RF engineers are quickly moving toward using multiple antennas, even for single-frequency operation. This strategy—known as multiple-input, multiple-output, or MIMO—allows for more reliable links and higher data rates. For example, IEEE 802.11n networking gear uses multiple antennas to communicate at about five times the speed of previous versions of Wi-Fi.

You can understand how MIMO works, at least in broad terms, with a simple thought experiment. Suppose you set up a transmitter with a single antenna and then move a receiver, also with a single antenna, far enough away for the reception to fade in and out once in a while. Such problems arise because the transmitted signal takes multiple routes to the receiver—some of it perhaps bouncing off a passing car, other parts reflecting off the steel beams of the building where the receiver is located. When the difference in length between two paths is half a wavelength (or three halves, or five halves, and so forth), the two waves will interfere destructively, clobbering the signal.

MIMO sidesteps that pitfall by multiplying the number of possible paths between transmitter and receiver. If the signal passed from one transmitting antenna to one receiving antenna fades, the signal from a different pair should still come in loud and clear, taking advantage of a phenomenon known to radio designers as transmit diversity.

Throw in some serious number crunching to process the digitized signals and you can achieve extraordinarily high data rates. Researchers at NTT DoCoMo, in Japan, which is developing such systems for 4G mobile communications, have managed 5 gigabits per second. And this wasn’t just in a controlled laboratory setting; they achieved this rate outdoors, albeit with the receiver moving no faster than a swift walking pace (doing the same while traveling down the highway would be much more difficult). Impressive results with MIMO and other advanced antenna systems are also coming out of Stanford’s Information Systems Laboratory, MIT’s Lincoln Laboratory, and the Center for TeleInfrastructure at Aalborg University, in Denmark.

Another tricky issue for the makers of SDR handsets is designing the transmitter’s power amplifier so that it can operate over a broad range of frequencies without mangling the signal. The challenge is not so great for FM transmission, but for communication schemes that require the amplitude of the wave to be manipulated, things can rapidly go awry.

Avoiding problems in such cases typically requires some kind of feedback mechanism. You can, for example, sample the output of the power amplifier and convert this RF signal to lower frequencies, which you can then compare with the signals used to modulate the amplifier. You can then compensate for any error you find by digitally adding the reverse distortion to the input signal. Among the leading manufacturers of such designs are RF Micro Devices, in Greensboro, N.C.; Acco Semiconductor, in Saint-Germain-en-Laye, France; and Axiom MicroDevices, in Irvine, Calif.

Another challenge for SDR designers is making much faster ADCs. To avoid ”aliasing”—the effect that makes rapidly spinning wagon wheels in old Westerns look as though they’re turning slowly, or even backward—the ADC must sample the signal at a rate at least twice that of the highest-frequency component, and this may be quite high. The upcoming 4G technologies, for example, are expected to operate in the vicinity of 3.5 gigahertz, which means you’d need to take 7 billion samples per second—more than 10 times as fast as what today’s best ADCs of sufficient resolution can manage.

Many SDR researchers consider this to be among the toughest obstacles ahead—not only because they must up the sampling rate so much but also because they’ll simultaneously need to make significant improvements in the signal-to-noise ratio, power consumption, and physical size of this circuitry. Typically, you can better one of these parameters only by making trade-offs with the others. So achieving gains on all fronts at once is going to be extremely difficult.

There is, however, a strategy that might allow direct conversion of RF in the not-so-distant future: purposeful subsampling. The trick here is to arrange the sampling frequency of the ADC so that the inevitable aliasing that occurs works to your advantage. In one step, the operation both digitizes the RF signal and converts it to a lower frequency. This may seem a bit magical, but it’s not so hard to understand. Just imagine the RF signal as one of those rapidly spinning wagon wheels. Adjust the frame rate of the motion-picture camera appropriately and your captured version of this wheel will turn at whatever lower frequency you want [see ”Aliasing Harnessed”].

Astute readers might notice that the difficulties we’ve outlined so far all involve hardware. Software-defined handsets will have some challenging software, too. It’ll manage the modulation, demodulation, encoding, decoding, encryption, and decryption, as well as the packing and unpacking of the data needed for the communications protocol employed—all computationally intensive tasks. What’s the best kind of microprocessor for such heavy lifting?

Most SDR designers struggling with that question instinctively fixate on the MIPS rate—how many million instructions per second the processor can execute. That’s because it must carry out a huge number of arithmetic operations—largely multiplications and additions—to massage the digitized signal. Specialized digital signal processors (DSPs) are usually the best chips for such things, but they may not be the only solution for SDR handsets. The reason is that these radios must do other kinds of signal processing, too.

In particular, SDR handsets need to detect and correct errors in the received digital bit stream, and the algorithms for that consist less of multiplications and additions than of ”if-then-else” statements. Those branching operations are better done by a general-purpose processor, which would normally also be assigned the tasks of running the unit’s real-time operating system, keyboard, and display. So a software-defined handset will need to have such a chip around anyway.

A general-purpose processor will also be required to host the software interfaces that connect different applications with the underlying hardware. In the near term at least, that ”middleware” is likely to conform to the rules laid out in the U.S. military’s Software Communications Architecture, an object-oriented computing framework that has become the de facto standard for software radios intended for combat use.

Designers of future SDR handsets will revel in the flexibility afforded by having the software control so much of the signal processing. And designers will no doubt want as much of the set’s hardware as possible to be reconfigurable—that is, they’ll want software to do not only signal processing but also be able to switch between different antennas and RF front ends. Such capability would allow you to turn a cellphone into a satellite-radio receiver, say, at the touch of a button.

While the technology for accomplishing this has been around for years, until now it’s been too bulky and power hungry to be used in handsets. But consumers are now on the verge of enjoying the fruits of this approach, implemented with modest amounts of power and in very small packages. In February 2008, BitWave Semiconductor, of Lowell, Mass., announced its BW 1102 Softransceiver RFIC, a chip intended to bring SDR to both cellphones and femtocells (small wireless base stations that can be set up in a home or business to improve cellular coverage indoors). The BW 1102 is a single complementary metal-oxide-semiconductor integrated circuit containing a transceiver that supports a variety of wireless protocols and can operate anywhere on the spectrum from 700 MHz to 3.8 GHz.

Suppose, however, that you are a radio designer and want more than BitWave’s chip can handle, such as the ability to receive FM broadcasts—and maybe even transmit on FM, too, so that you can play your favorite MP3 files on your car radio. How hard would it be to create the perfect IC for that? Hard indeed, it turns out, and that’s why BitWave still has essentially no competitors.

But let’s say you’re keen to try. You might start by estimating the allowable execution time for each of the radio’s intended functions and its power consumption, physical size, and other properties, including the frequency bands to be covered. Based on that assessment, you’d decide how to divide the overall system into hardware and software. Although this exercise isn’t trivial, tools for hardware-software codesign are available.

Now comes the more difficult job: You’ve got to come up with detailed designs for each piece. Fortunately, you won’t have to do that from scratch. Suitable designs for at least some of the larger building blocks—a DSP here, a general-purpose processor there—should be possible to find and license. After the hardware has been pinned down, you’ll need to pull together the software to run it, which itself should keep you and your team busy for a large number of programmer-years.

The next challenge is to verify that your radio works correctly. Unfortunately, even state-of-the-art simulation tools aren’t guaranteed to show system performance properly—and subtle errors here might be lethal for your product. Worse, many of the expected mobile services may be safety critical, so a tiny slip-up could be a literal killer, too.

One way to address this uncertainty is to go a step further than simulation: You can prototype the digital portion of your newly designed SDR system using one or more field-programmable gate arrays (FPGAs), integrated circuits that contain a vast number of logic blocks and potential interconnections. These devices can be configured after their manufacture to serve almost any purpose, constituting entire systems on a chip.

The problem with FPGAs for production is that they are the energy hogs of the semiconductor world, lacking the power-management features of their hardwired counterparts. Moreover, FPGAs suffer from the integrated-circuit equivalent of suburban sprawl, taking up a relatively large area on a silicon wafer. They are also expensive, which helps to explain why we haven’t seen FPGAs being used to manufacture SDR handsets—at least not yet. A few researchers are exploring low-power FPGA technologies, so it’s not out of the question that they could one day serve for high-volume production of handsets.

In the meantime, FPGAs remain a convenient way to build and test SDR prototypes. Among the most interesting examples of this is the Berkeley Emulation Engine 2 (BEE2) project at the University of California, Berkeley. This test-bed setup consists of five high-performance FPGAs, which with proper programming can be turned into various next-generation SDR systems. Another example of this approach is the SDRâ¿¿based design effort at San Diego State University, which became widely known through a 2007 article in DSP Magazine titled ”How to Pack a Room of Analog FM Modulators Into a Xilinx FPGA.”

No doubt, many people are waiting for the day when they’ll carry just one handheld gadget they can instantly switch from cellphone mode to that of a satellite radio receiver, or from a wireless Web browser to a mobile TV set; indeed, their handset might carry out all of these functions at once. Others, including the world’s many technophobes, might be less enthusiastic about such a prospect. But SDR technology offers something for them, too—the possibility that their wireless equipment will eventually become smart enough to adapt to its communications environment all by itself.

A radio intelligent enough to reconfigure itself—perhaps by detecting free spectrum and switching its frequency of operation to claim it—would make wireless services cheaper and more reliable for their users, most of whom will not even be aware that such marvelous things are going on under the hood. As with SDR, this is a concept that Mitola promoted early on, in a 1999 article he wrote with Gerald Maguire Jr., of the Royal Institute of Technology, in Stockholm. They called it cognitive radio.

Ah, to have a radio that not only switches function on demand but also configures itself into the most effective form possible without its user even knowing it. Now that will be a truly universal handset.

About the Author

PETER KOCH and RAMJEE PRASAD, who explain how software-defined radio will soon transform cellphones in ”The Universal Handset”, are professors at Aalborg University, in Denmark. Koch works at the university’s Center for Software Defined Radio and also operates an amateur radio station for fun. He’s shooting to reach other hams in all parts of the world. ”I’m not there yet,” he says. Prasad, an IEEE Fellow, heads the university’s Center for TeleInfrastructure. He, too, enjoys making international contacts, but rather than doing so wirelessly, he regularly travels to the far corners of the world.

March of the SandBots ( IEEE news )

noreply@blogger.com (John Roach) — Sun, 26 Apr 2009 13:41:00 +0000

By Daniel Goldman, Haldun Komsuoglu, and Daniel Koditschek

PHOTO: YVONNE BOYD

A zebra-tailed lizard stands on a bed of tiny glass beads and shifts its weight. The beads slip underfoot, and the mottled beige creature stretches its spindly toes to get a better purchase. Suddenly it breaks into a run, blazing across the granular surface with stupendous agility, its toes stretching out flat as they hit the beads, its feet whipping back and forth in a blur. Each side of the lizard’s body stretches and then coils in turn as the reptile darts ahead at several meters per second.

Scooped up a year ago in California’s Mojave Desert and transplanted to a lab at Georgia Tech, the lizard holds our interest because of its truly peculiar feet. Those long, bony toes allow the reptile to navigate over sand, rocks, and the many other types of terrain it may face in the desert. In the lab, the bed of glass beads stands in for desert sand, and by blowing air through it or packing it down, we can make the ground looser or more solid. We then study how the lizard copes with the changes.

Our interest isn’t purely biological. We—Goldman at Georgia Tech, Koditschek and Komsuoglu at the University of Pennsylvania, in Philadelphia, and our other collaborators—are hoping that by studying the zebra-tailed lizard and a menagerie of other desert-dwelling creatures, we can create more agile versions of our six-legged robot, SandBot. When traversing solid ground, the robot runs at a steady clip of two body lengths per second. (For comparison, a trotting dog covers four body lengths per second.) But on its first outing across the glass beads, SandBot dug holes fruitlessly with its crescent-shaped feet and got stuck after just a few steps.

Sand, it turns out, is one of the most difficult terrains for a robot to conquer. Sand is slippery, for one thing, and it is also inherently unstable: Its properties can easily flip between solid and fluid behavior in the course of a single footstep. Physicists still don’t have a complete picture of the mechanics of sand, which is why we’ve turned our attention to the lizard and the clever strategies it has evolved to cope with sandy terrain. For example, we have noticed that the lizard’s long toes sink deep into the sand at each step. It appears that this allows it to push off from sand that’s deeper and more solid than the less stable surface layer. The effect, preliminary evidence suggests, is that the sinking enables the lizard to run as if on hard ground, allowing it to maintain speeds up to 75 percent of its pace on solid ground. Desert animals deal with sand with different levels of success, and their techniques provide valuable clues for refining SandBot.

Ultimately, we would like to build robots that can traverse any kind of terrain—bounding across hard ground like a gazelle, scaling tall trees and buildings like a squirrel, or maneuvering over slippery piles of leaves or mud like a snake. At least for short periods, a few robots already have managed to scale vertical walls, leaf-covered slopes, and even ice. Eventually, highly mobile robots could make a big difference in search-and-rescue missions and could explore all kinds of tricky terrain, not just on Earth but on the moon, Mars, and beyond.

First, though, our machines need to conquer sand. Had we been designing a wing for flying or a flipper for swimming, we would have been guided by the well-established rules for fluid flow, the Navier-Stokes equations. But for a complex material like sand, the equivalent models do not yet exist. So we had to start at the very beginning, by investigating the physical properties of granular materials. After about two years of study and experimentation, we in our small consortium of physicists, roboticists, and biologists think we have identified some basic rules describing movement across granular surfaces. Applying that knowledge to designing sandworthy robots, though, is not at all straightforward.

Consider how humans transport themselves over land. In places where massive investments have been made in roads and tracks, it’s relatively simple to move about by car or train. In fact, our vehicles require all of that engineered smoothness—without it, they can’t go far. But much of the Earth’s surface is largely inaccessible to vehicles, including robots. About 30 percent of the land area is desert, and one-fifth of that is covered by some kind of sand.

Sand isn’t the only issue. Disaster sites and battlefields—precisely the places where mobile robots are expected to be most useful—are full of unpredictable, impassable rubble. In 2001, for example, robots were sent in after the World Trade Center towers collapsed, but debris quickly clogged their tracks or caused the robots to flip over. Likewise, when a coal mine collapsed in Sago, W.Va., in 2006, a rescue robot made it about 700 meters past the mine’s entrance before getting stuck in mud. Even benign stuff like gravel and fallen leaves can stop a robot cold.

In short, robots that navigate on wheels and tracks are nearing their performance limits. Legged robots that mimic the movements of insects or animals offer a promising alternative, but figuring out the mechanics of walking hasn’t been easy. Because not much is known about how the forces between a foot and the ground interact to create movement, the prevailing method for designing these robots has been essentially trial and error: Build the machine and hope for the best.

But we’ve come a long way. The first computer-controlled legged robot dates back to the 1960s, when Robert McGhee’s Phony Pony took its first halting steps at the University of Southern California, in Los Angeles. McGhee then followed up on that project at Ohio State University, in Columbus, creating the first autonomous legged robot in 1976. This machine, known as Hexapod, could make its way slowly across some wooden blocks indoors.

A decade later, McGhee and his colleagues’ 5-meter-long Adaptive Suspension Vehicle was the first autonomous legged machine to tackle the great outdoors. Moving ponderously at a fraction of a body length per second, the robot carefully placed each leg and then torqued its joints to generate the necessary ground-reaction forces to push its body forward.

The next phase in legged robots was ushered in with the dynamically dexterous machines built by Marc Raibert at Carnegie Mellon University, in Pittsburgh, and later at MIT. Dynamic dexterity is the ability to exchange potential energy and kinetic energy in a controlled manner—or the difference between a hopping kangaroo and a car. A kangaroo’s bent legs store potential energy, which allows it to bound effortlessly over obstacles. The ability to direct its body’s flow of mechanical energy is critical for a robot to navigate unpredictable terrain. Raibert’s creations were essentially self-excited pogo sticks that used springs to balance, hop, and when yoked together, trot and bound. These robots still hold the ground speed record of 21 kilometers per hour, but they were strictly designed for controlled laboratory environments.

The RHex robot, designed by the roboticist Martin Buehler (then a professor at McGill University, in Montreal) and Koditschek’s group in 1999, took running robots to the next level. This autonomous machine, inspired in part by integrative biologist Robert Full, of the University of California, Berkeley, has six legs that are attached outside its center of mass. This sprawled configuration grants the robot greater stability as it bounces over natural terrain. Faster runners have since appeared, but RHex remains, to our knowledge, the only legged machine that can traverse rugged, broken ground rapidly—at or above the pace of one body length per second.

RHex in turn became the model for a family of robots whose appendages are each driven by a motor located at the hip. Its progeny include, among others, the Aqua robot, which is basically RHex with flippers for swimming; a two-armed, wall-climbing robot named Dynoclimber; and SandBot.

PHOTO: YVONNE BOYD

In early 2007, Komsuoglu designed and built SandBot in less than a month, using the RHex model and a modular infrastructure of his own creation [see “Seeing Inside SandBot”]. At 2 kilograms, it is less than a quarter of the weight of RHex. Like RHex, SandBot has six compliant, independently controlled legs, each of which is a semicircular strip of plastic. Also like RHex, it walks with an “alternating tripod” gait, inspired by insects. The legs move in threes, with the front and rear leg on one side moving in sync with the middle leg on the opposite side. The two tripods alternate supporting and propelling the body, then circle around after each step.

On the inside, SandBot is composed of modular nodes that communicate through a real-time network called RiSEBus, inherited from an early version of its climbing sibling. At the hip joint of each leg sits an 11-watt brushed dc motor driven by a custom-designed motor controller board with a quadrature encoder, which senses the position of the motor’s shaft and therefore the angular position of the leg. The six motor controllers link to a central computer, which functions as SandBot’s brain and focuses on high-level behavioral decision making. Commands from the central processor instruct the motor controllers to bring the legs to a desired position and speed. A position-tracking controller determines the discrepancy between a leg’s actual state and the desired state. The controller then computes the voltage needed to correct the error and applies it to the motor using a class‑D power amplifier. This action gets the leg into position at the right speed.

To economize on the robot’s computational power, the computer issues commands at the comparatively lazy rate of about 100 times a second, which frees up its cycles for other tasks. The central processor might, for example, tell one of the microcontrollers that its leg should move at a particular speed starting from a certain position. From then on, all tracking of that leg’s position is carried out by the microcontroller, which can interrogate its sensors at the much higher frequency of 1 kilohertz.

This design allows the central processor to communicate with the legs using extremely compact data packets that require minimal computing power to decode. The separation of the control tasks frees up the central processor to perform longer-range planning. The central processor might use a camera to assess the difference between its relationship to a visual landmark and what it ought to be or investigate how treacherous a surface is based on tactile feedback it retrieves from sensors in the legs.

SandBot’s design builds on experiments in Goldman’s lab with real sand creatures. The zebra-tailed lizard, for example, can maintain a high speed over sand of almost any kind. The ghost crab, by contrast, is less versatile; on packed ground, its limbs and feet extend out from its 4-centimeter shell, and it scuttles along at a rapid 1 meter per second. But on looser soil the crab gets bogged down. The wind scorpion, for its part, can cover several body lengths per second even on granular slopes, where every step could trigger an avalanche.

Our observations of the lizard, crab, and scorpion under different conditions have helped shape our theory of sand locomotion. We believe this project represents the first attempt to combine direct measurements of a flowing physical substrate with observations of a runner’s impact on the ground and its body movements. Broadly speaking, an animal’s weight, foot shape, and gait all work together to apply a specific amount of stress to the sand. Under that model, the lizard is accessing the solid features of sand rather than slipping through the material and paddling, which is what the ghost crab ends up doing on softer terrain.

Much can be learned even from a single footstep. With each stride, the drag forces generated when a foot moves through sand can display both solid and fluid properties. If the stresses generated by the foot exceed a certain threshold, the material will flow. But it can also suddenly solidify if the stress drops sufficiently. That can happen, for example, if the downward forces produced by the limb and the weight of the robot are balanced by the amount of pressure within the sand, which is a function of its depth.

Another facet is that the behavior of sand depends on what’s happened to it in the past. A section of solid sand disturbed by a footstep may be more loosely packed when the next foot hits the material, for example. The forces generated by a foot stepping into these different conditions can vary dramatically—the penetration resistance varies by a factor of 1.6 between a tightly packed material and a loosely packed one. That complicates the task of predicting how far a limb will penetrate in different granular states.

To learn how SandBot can best maneuver in sand, we have been subjecting it to a variety of precisely controlled granular environments. We control the environment using a 2.5-meter track built by Chen Li, a graduate student in Goldman’s laboratory in Atlanta. The track looks sort of like a long bathtub, and it’s filled with 90 kg of poppy seeds. There are tiny holes in the bottom through which we can blow air, causing the poppy seeds to lift off and dance before settling into a loosely packed state. (Why poppy seeds and not actual sand? We’ve found that each seed is large enough to keep us from worrying about it getting into the motors and yet light enough to be lofted by our air puffs. From separate experiments, we know that the exact material doesn’t matter, as long as it is made up of granules.)

With sand and other granular media, we can describe the “strength” of the ground in terms of its solid volume fraction—that is, the fraction of the total volume occupied by the granules. Typically, the solid volume fraction falls between 58 and 64 percent for materials like sand or piles of seeds. A lower fraction means that, on average, there are fewer points of contact between the grains and that the material is less solid. In our test track, an exact sequence of hundreds of air pulses carefully packs the poppy seeds to the desired volume fraction.

Because RHex had been so successful at walking on a variety of surfaces, we assumed that the smaller but relatively more powerful SandBot would perform well on sand. We were wrong. In an early experiment, we packed the material to a solid volume fraction of 63 percent, placed SandBot on the surface, and set the frequency of the alternating tripod gait to 5 revolutions per second. Earlier, the robot had bounced flawlessly across hard ground using those same parameters.

This time, though, it got stuck after just a few steps. Like a car’s tires spinning in mud, the robot’s rapidly rotating legs produced absolutely no forward motion on the poppy-seed-filled track. Discouraged, our first assumption was that SandBot was simply too heavy to walk on sand and that we would need to completely redesign the robot.

But we decided to play around with it a bit more. Komsuoglu, conferring by phone from his office at Penn, suggested that we modify the gait slightly to make the legs swing faster in parts of the cycle and slower in others. He knew from previous studies he’d done that some robots perform better with such a varied gait, at least on hard surfaces. It seemed worth a shot. As Komsuoglu told us over the phone which values to change, we entered them into the control program and, like magic, the robot started to move! The robot was still cycling its legs five times per second, but now it was scurrying down the track at one body length per second. Further study showed that each limb penetrated the poppy seeds until it supported the robot’s weight, providing enough stability for the machine to thrust up and forward.

With Paul Umbanhowar, a mechanical engineer at Northwestern University, we subsequently developed a kinematic model explaining the relationship between the volume fraction, the limb rotation frequency, and the depth of the limb’s penetration at each step. As both the model and empirical evidence show, if we increase the frequency with which the robot rotates its limbs, the robot sinks further into the material and the size of each step decreases, triggering a catastrophic loss of speed—quite the opposite of what happens on hard ground.

Another improvement we’re working on is building SandBot a better foot, to give it the ability to grip sand just as the zebra-tailed lizard does. To that end, we’ve been measuring the forces on the foot during impact with and penetration of materials of different volume fractions. The tests look deceptively simple: We embed accelerometers into simple disc-shaped objects and then drop them on piles of sand. The results show that the forces produced when a foot hits the ground have different qualities in high- and low-volume-fraction materials. When the sample foot falls into a low-volume-fraction material, the force on it increases until the object comes to rest. When the object falls into a closely packed material, the force decreases during penetration.To also investigate the drag and lift forces that arise during the other parts of each step, we use a robotic arm to maneuver model feet and toes along granular paths.

To fully model the behavior of individual granules, we must resort to simulation. Yang Ding, a graduate student of Goldman’s, has developed a computer simulation that models collisions of objects with sand, beads, and other granular media. We hope that eventually these foot experiments and simulations will feed into the development of a new sensing and control system for SandBot, to enable it to sense the shifting terrain ahead and swiftly adjust its gait to match. Sand isn’t the only morphing environment that the robot could eventually tackle: Mud and loose leaf litter also display the solid and fluidizing features of granular media.

Our observations of the lizard, the crab, and the scorpion have helped shape our theory of sand locomotion

Indeed, with physics models built into their feet and brains, robots should one day be able to scramble across a rocky or sandy environment and learn, on their own, how to handle the changes in terrain from footstep to footstep. We can imagine thousands of SandBots scouring the surface of another world, stepping from a pile of rubble to a sandy patch with ease. That’s still a big challenge for today’s machines, but it’s something even a hatchling sea turtle can handle. Despite having appendages that are better suited for swimming, these remarkable animals must climb out of a deep hole in the ground, clamber over grass and debris, and move across sand to reach the water, where they will spend much of the rest of their lives.

We’re also looking below ground for inspiration. Using high-speed X-rays, we are now studying lizards called sandfish that can burrow into sand in the blink of an eye and then “swim” through the material underground. We’re hoping these creatures will provide clues as to how robots could scramble through an unpredictable disaster area after an earthquake or flood or dig down to detect land mines. With nature as our guide, we expect that robots will soon master some incredible new abilities.

Latest And Greatest On Processor Front

noreply@blogger.com (John Roach) — Sun, 19 Apr 2009 19:30:00 +0000

Channelweb goes into the field to see what one California-based system builder is doing with Intel's Nehalem and Nvidia's Tesla processors.

The NVIDIA® Tesla™ C1060 transforms a workstation into a high-performance computer that outperforms a small cluster. This gives technical professionals a dedicated computing resource at their desk-side that is much faster and more energy-efficient than a shared cluster in the data center. The Tesla C1060 is based on the massively parallel, many-core Tesla processor, which is coupled with the standard CUDA C programming environment to simplify many-core programming.

AND THEY HAVE MADE A PERSONAL COMPUTER!!!!!

Features and Benefits

Industry's first massively multi-threaded architecture with 240-cores.
Many-core architecture delivers optimum scaling across HPC applications.
Optimized for scientific computing, delivering up to 15x cost savings, 20x lower power, and 250x the performance than traditional 1U rack-optimized servers or desktop workstations.
Scale to thousands of processor cores to solve large-scale problems by splitting the problem across multiple GPUs.
High-efficiency computing platform for energy-conscious organizations.
NVIDIA CUDA Technology unlocks the power of Tesla many-core computing products.
Seamlessly able to fit into existing HPC environments.
Ideal for life sciences, geosciences, engineering & sciences, molecular biology, medical diagnostics, electronic design automation (EDA), government and defense, visualization, financial modeling, and oil & gas applications.

Specification

Up to four Tesla processors (240 computing cores per processor, 960 cores total)
Delivers up to four teraflops in a tower chassis
IEEE 754 single & double floating point precision
Up to 16 GB dedicated memory (organized as 4.0 GB per GPU)
Up to 4 x 512-bit GDDR3 memory interface (organized as a 512-bit interface per GPU)
Up to 408 GB/sec memory bandwidth (102 GB/s per GPU to local memory)
Ultra quiet, eloquent tower chassis
System dimension: 23.6" x 9.6" x 24.6" (H x W x D)

Sign Language by Cellphone

noreply@blogger.com (John Roach) — Sun, 19 Apr 2009 12:58:00 +0000

By Philip E. Ross

PHOTO: UNIVERSITY OF WASHINGTON

In the past, engineers working on technology to aid the deaf had focused primarily on hearing devices, such as hearing aids and cochlear implants, but recently they’ve been getting into what’s known as deaf technology: applications designed to make the day-to-day lives of the deaf and hearing-impaired easier. Now engineers from the University of Washington, in Seattle, and Cornell University, in Ithaca, N.Y., have taken a big step toward developing a mobile phone that allows real-time conversations in sign language.

Of course, many in the deaf community already use mobile phones to communicate via text messaging and e-mail, but deaf people almost always prefer sign language: It’s faster and more natural, just as speaking is easier than writing for most hearing people. Laptops are getting smaller and more portable, making video chats outside the home possible, but Wi‑Fi–enabled cellphones would provide even more freedom. When cellphones became capable of video sharing a few years ago, Eve Riskin, Sheila Hemami, and Richard Ladner, all newly minted IEEE Fellows, felt the time seemed right to develop a sign-language-capable phone. “Today’s world is more connected by cellphones than by any other device,” says the University of Washington’s Ladner, whose parents were deaf.

From the beginning, the researchers knew that their project, which they named mobileASL (for mobile American Sign Language), would be a challenge. The low bandwidth available on wireless networks in the United States forced them into the balancing act between speed and quality that’s familiar to anyone who works with video, but there was an added twist. Most compression algorithms don’t focus on the aspects of video that would make ASL easily understandable, says Riskin, an electrical engineering professor at the University of Washington.

Hemami studies how the human visual system understands video at Cornell University. To help solve the problem, she has been working on integrating an intelligibility metric into the team’s video-compression software that would enable mobileASL phones to maximize comprehension. It accomplishes this, in part, by recognizing which areas of the image need to be in high resolution—such as the signers’ hands and faces—and which areas, such as the signers’ torsos, can be in low resolution.

The team also had to figure out how to preserve the phone’s battery life in the face of the power-draining compression and decompression that conversing by video requires. They tackled this problem by implementing a variable frame-rate system that oscillates between high and low frame rates depending on whether the user is signing or watching the other person sign.

Now, nearly four years after they began, the researchers are finally close to a functional prototype. A few months ago, Riskin and her lab at the University of Washington figured out how to increase the frame rates to more than 10 frames per second, a critical step for making mobile video conversations clear and realistic. The mobile phones they were working with weren’t capable of processing full-size images at that rate, but by sampling only a quarter of the pixels in each frame, the group was able to make the video-compression process about four times as fast. Fortunately, the interpolation feature in the Microsoft Windows Mobile operating system automatically expanded the resulting videos back to full size without a significant decrease in quality.

The team still faces one big challenge, which is finding the best way to get the mobileASL software into the hands of the people who want it. The group wants the application to be as broadly usable as possible. They are testing it over a Wi-Fi connection but are also experimenting with the data services of several wireless carriers.

Magical Murals!!

noreply@blogger.com (John Roach) — Fri, 20 Mar 2009 08:00:00 +0000

Stop That Train!

noreply@blogger.com (John Roach) — Mon, 16 Mar 2009 21:47:00 +0000

By Robb Mandelbaum

PHOTO: NEW YORK AIR BRAKE

WHOA!: A Norfolk Southern Railway freight train equipped with a new electronically controlled pneumatic (ECP) braking system comes down a mountain. It is the second such train that the company has equipped with ECP brakes. 

George Westinghouse’s many inventions rank him with Thomas A. Edison and Werner von Siemens as founding fathers of our electrified world. Yet, ironically, Westinghouse’s first invention, a railroad brake he patented in 1869, was actuated not by electrons but by air. To this day, most railroads rely on that system’s principle of releasing air from a pressurized pipe that runs the length of the train and brakes the cars one after the other, at a rate of 152 meters per second.

To compound the irony, some of Westinghouse’s early competitors proposed electrical mechanisms, but Westinghouse himself rejected these as unreliable. In the past decade, however, the idea has reemerged in a hybrid system that uses an electronic system to control a pneumatic one, so as to set the brakes in all the cars simultaneously. So obvious are the advantages of the new technology—called electronically controlled pneumatic braking, or ECP for short—that its manufacturers are optimistic it will eventually sweep the field.

“We believe that the benefits of ECP will be clearly proven,” says Robert Bourg, vice president and general manager of Wabtec Railway Electronics, in Germantown, Md. The parent company, Wabtec Corp., headquartered in Wilmerding, Penn., and the successor to the Westinghouse Air Brake Company, is one of two American companies bringing electronic-pneumatic train brakes to market. The other is New York Air Brake (NYAB), a subsidiary of Germany’s Knorr-Bremse, in Munich.

Two major U.S. railroads have recently begun running

WHERE THE ACTION IS: The locomotive’s open compartments [1] reveal the electronically controlled braking system’s power supply (white box) and the central control unit (yellow); the red handle in the cab controls the freight car brakes, while the black handle controls the locomotive brakes [2]; and pneumatic and electric cables run from car to car [3 The microprocessor-based car-control device [4] replaces the old triple-valve system; the cables hang loose at the end of the train [5] and then terminate in a junction box (red panels), which can be opened for cable replacement [6 ]

PHOTOS: NEW YORK AIR

, one using Wabtec’s, the other NYAB’s. If ECP brakes catch on here, they’ll likely appear on heavy-haul railroads around the world, especially in regions that adhere to American Association of Railroads (AAR) standards, including southern Africa, Brazil, Australia, even China.

But will ECP, in fact, catch on? Believe it or not, its ultimate victory is not a foregone conclusion. Standing in the way of implementation are steep up-front investment costs and disagreements over who should shoulder them. Such impediments appear whenever an insurgent technology challenges an incumbent—for example, digital projectors in movie theaters and digital TVs in living rooms. And of course, market forces are not the only actors here. Railroads are heavily regulated—and regulation can make all the difference.

The Westinghouse air brake, though updated periodically, retains the basic character it’s had since the 1870s, even as trains have grown much longer and heavier. The locomotive forces air into a pipe that runs the length of the train and connects to a triple valve in each car; that valve connects both to the car’s auxiliary air tank and to its brake cylinder. The relative pressure of the air in the three devices determines the action.

To activate the brake, the engineer drains air from the pipe, causing a disequilibrium of pressure in the valve that moves a piston, which opens a passage from the reservoir tank to the cylinder; this opening, in turn, allows the air to rush in and set the brake. This is a fail-safe design, because if the train were somehow to break in two, the rupture in the pipe would automatically apply the brakes. To release the brake, the engineer sends air down the pipe once again, which fills each car‘s reservoir in sequence.

But all this takes time—a 100-car train traveling at 80 kilometers an hour would require at least 1 km to stop. It also takes time to undo the process and get the train moving again.

“We’ve had long trains where the engineer released the brake and started pulling a little bit too early, while the brakes were still set on the rear of the train,” explains Dana Maryott, director of locomotive and air-brake systems at the Burlington Northern Santa Fe (BNSF) Railway. “And coming around a sharp radius, we’ve literally pulled the train off the track.”

Taking a freight train down a long incline is particularly complicated because air brakes cannot be gradually released, the way they are in an automobile, for example. If you try to increase the pressure in the air pipe just a little, the signal will decay after about 600 meters, and it will never reach the brakes in the rear.

To get a feel for the old Westinghouse system, I’ve come to Bluefield, W.Va., at the eastern end of the Norfolk Southern Railway’s Pocahontas Division, 167 km uphill from Roanoke, Va., and another 450 km from the great shipyards of Norfolk and Newport News. Bluefield is America’s oldest “hump yard“; it straddles the crest of a low mountain, so that cars unhitched from the locomotive will roll down to switches where they can be shunted onto the desired tracks.

Today, arriving engineers still drape their trains over the crest so that half the train is parked on each side of the hill. Once you start heading down,” says Mike Allran, a senior engineering specialist with Norfolk Southern, “gravity’s really going to start pulling on that train good. That’s what makes it tough getting off the mountain out here.”

Sometime after 1 p.m., Train 762—two long black locomotives pulling 110 shiny aluminum cars, each heaped with over 90 000 kilograms of West Virginia coal—arrives at the Bluefield crest. The train, bound for the power plant at Hyco Lake, N.C., stretches nearly 2 km and weighs nearly 18 million kg. I climb aboard Engine 9191, along with Allran, road foreman Chuck Peters, and engineer Jeff Hayslett, while conductor Norris Kasey takes his brake stick and walks alongside the train setting air retainer valves on 10 cars. The valves reserve about 62 kilopascals of air in each brake cylinder, just in case; those cars will be slightly braked all the way to Roanoke. A few minutes later, Hayslett radios his dispatcher and then turns to the rest of us. “Everybody ready to roll?” he asks, and he begins ringing the engine’s bell.

Hayslett eases into his throttle to pull us over the hump, but it isn’t long before he turns to the brakes. The Norfolk Southern, like most U.S. railroads, teaches engineers to control the train as much as possible with the locomotives’ dynamic brakes, which slow the engines by reversing the electric current that powers their traction motors.

In practice, this means Hayslett uses the air brakes to set a base level of braking and the dynamic braking to modulate it. But here the air requires its own precision: If you’re short a couple of pounds per square inch, the train might get away. (One pound per square inch is just under 7 kPa.) But if you’re a couple of pounds over the mark, the train will stall, and you’ll have to fully release the brakes (or “knock off the air”) and then set them up again, probably before the reservoirs are fully charged. In the cab it’s known as “pissing away your air.”

“If you get your train set up the first time right, it means when you go down the mountain you ain’t gotta fight the train,” Hayslett explains. Otherwise “the train’s gonna be working you instead of you working it.”

He applies the dynamic brake, and we can feel a great number of gentle bumps as each hopper rolls into the one that preceded it. A few minutes later, with the train bunched up and the speed approaching 21 km/h, Hayslett grips a lever with two hands and reduces the brake pipe air by 8 pounds. His plan is to knock the air off at milepost N350, a flat spot in the grade where he’ll have time to recharge the system before setting the brakes up again. Next he’ll release the brakes again at Oakvale, W.Va., and then again several miles later, at the start of a very long stretch of flat running.

We breeze through the Virginia countryside. It’s a bright day in May, cool and green in the mountains. At Glen Lyn we meet the New River and follow its winding, tree-shrouded banks, first on one side, then on the other, for the next couple of hours. Then, after a long slog up a 16-km hill, we approach the entrance to the Merrimac Tunnel. Burrowing down for 1.5 km, with a grade of just over 1 percent, the tunnel presents an unusual braking challenge. Without braking, the train will gather momentum quickly. But Hayslett can’t apply the air brakes while he’s in the tunnel.

“Anytime you put the air on, you’re subject for something to go wrong,” explains Peters. Peters is thinking specifically of what’s called a kicker, a sticking valve so sensitive to a reduction in brake-pipe pressure that it begins emergency braking and “kicks” the train swiftly to a halt. Braking miscues like this are called undesired emergencies, and they’ve grown more irksome for railroads in the last 20 years.

Traveling at 32 km/h, our train could stop in as little as 20 seconds if the brakes were applied at full force, Allran supposes. But then the forces acting on the train might be severe enough to cause it to derail. “You don’t want to do that in the tunnel,” Allran says. It’s a matter of fine judgment, notes Peters, who adds that of the 94 engineers he supervises, “there are three or four I wouldn’t want to go down the mountain with.”

Any system dependent on continual human intervention can only be refined so much. By the early 1990s, “the railroad industry recognized that the current air-brake system was an extremely mature technology,” says Fred Carlson, who recently retired as a research engineer for the AAR. “There was very, very little room for improvement.”

In 1991, Dana Maryott and his colleagues at Burlington Northern approached TSM, a small company based in Kansas City, Mo., to develop electronically controlled air brakes. A 65-car coal train, known as a unit train because the cars stay together over many runs, made its debut in October 1993. (New York City’s Metro-North commuter railroad and some other relatively short and interconnected commuter trains, in Europe as well as the United States, have for decades used a fairly rudimentary electropneumatic brake system, but it’s not the one visualized for long freight trains.)

Within two years, the line began experimenting with four more such ECP trains. Each car had a manifold that outwardly resembled the old triple valve, but the system took its cues from a portable computer that stored the car’s unique ID and some performance characteristics, such as its empty and loaded weights. The car control devices, as they came to be called, were in turn controlled by a computer in the locomotive.

In 1995, the AAR, which was separately investigating alternatives to air brakes, convened a committee of railroaders and brake suppliers to write the standards that would govern the new system’s performance and interoperability. They soon faced a fundamental choice: Should the electronic signal to the computer on each car be transmitted by wire or radio?

A wire, like a conventional brake pipe, would need to run uninterrupted the length of the train, meaning that every car would need to be equipped with the new system—a potential logistical quagmire for American railroads, which constantly swap equipment with one another. But a wireless system posed its own problems. Not only would a radio-controlled system require more power (to support the radio in addition to the control circuits), but each car would have to have a power source of its own robust enough to withstand a rugged, moving environment. “We looked at axle generators, air generators, and solar power,” recalls Bryan McLaughlin, who led the ECP team at New York Air Brake, “and none of that technology was reliable and cost-effective enough to put on the cars.”

Moreover, “you need a lot of redundancy and a lot of security for the messaging so that it doesn’t get jammed,” adds the AAR’s Carlson, who coordinated the committee. “Very early on, we had a lot of communications people tell us that if you can do it with a cable, do it with a cable.”

Ultimately, the AAR did do it with a cable, choosing a power-line transceiver by Echelon Corp. , a San Jose, Calif.–based supplier of network control equipment, to thread the signal protocol through the train. The locomotive power supply is 230 volts, based on a 150-car train up to 12 000 feet (3658 meters) long, consuming 10 watts per car.

Additional experiments on other roads followed. But as Carlson’s team finished its first draft in 1997—”probably the best specification the AAR ever wrote,” he says—a funny thing happened: The railroads started to lose interest. At first, “they were pretty much all on board. They wanted a new system, not necessarily interchangeable with the old,” says Carlson. “And then of course, after we developed it, problems began because it wasn’t interchangeable with the old.”

You might think interchangeability wouldn’t be a problem in the United States, where today seven major carriers handle 90 percent of the industry’s business. But there are 560 railway companies in all, operating on short lines and in terminals, and most trains are still strung together and broken apart by turns. In theory, a single incompatible car could thwart an entire train’s braking system, and a single stubborn company could foil implementation across the entire network.

An eye-popping price tag for brake conversion compounds the problem. In a 2006 study commissioned by the Federal Railroad Administration (FRA), Booz Allen Hamilton estimated conversion costs at roughly US $40 000 per locomotive and an average of $4000 per freight car; converting the entire North American 2006 fleet would run to about $7.5 billion. (In 2006, the total capital investment of the seven largest railroads was $8.2 billion.)

Who would pay for the transformation, and who would reap the rewards? Hundreds of operating companies own elements of the U.S. freight car fleet, and half the fleet is owned not by railroads but by utilities and giant finance companies that lease them to shippers and railroads. Car owners, complaining that railroads will derive a disproportionate benefit from new technology, want a subsidy of some sort. Railroads, for their part, have a lot of competing needs for scarce capital investment—an AAR report released last year calls for $148 billion over 30 years for “new tracks, signals, bridges, tunnels, terminals, and service facilities.”

Saddled with a hard sell in the United States, the ECP manufacturers gamely turned their attention to other markets. In 1998 New York Air Brake outfitted a single train in Quebec’s far northeast for Quebec Cartier Mining, which hauls ore on a treacherous route down a mountain 418 km to the St. Lawrence River. Wabtec won a contract to field ECP on a mining train for Spoornet, South Africa’s national freight railway company.

In the back laboratory at Wabtec’s electronics division in Germantown, a full-scale but stationary freight train with 150 empty cars is pretending to brake. The brake pipes that normally run underneath each car arc overhead instead—2560 meters of tubing connected by regulation hoses and couplings clasped as if in a firm handshake. Beneath this skeletal canopy are the air tanks and manifolds and cylinders. From these structures rods emerge that are normally connected with brake shoes but in this case are attached to small white markers. Braking is noisy but brief.

Chuck Wolf, Wabtec’s principal systems engineer, pushes his joystick. Instantly the rods in 150 brake cylinders extend outward, and a fleet of white flags glides forward in unison. The air pounds into the cylinders in bursts, chuffing and clanging like a steam locomotive. But after 12 seconds, the noise fades away—the brakes are all set. A few moments later, Wolf releases them, and the train emits a quickly dissipating, cacophonous hiss.

Wolf applies the brakes again, this time with the equivalent of a gentle squeeze. It’s over in 3 seconds. Then he tries a somewhat firmer application. At one point a blast of air unexpectedly explodes in the room, and a flag slides back toward the cylinder. Something has gone wrong with the brakes in Car 149, so the car’s onboard computer takes them off-line. This now registers on a screen in the locomotive, which reports that 95 percent of the brakes are working.

“The operator in the cab gets much more information than he ever had before,” Wolf says. Brake data is only a beginning: The ECP cable is a platform for sensors that will one day allow the engineer to monitor other conditions, such as the status of wheels and bearings.

Lately the FRA has been lauding ECP for the safety advantages it makes possible by keeping the auxiliary reservoirs filled with air so that gradual release can be managed properly. “ECP brakes are to trains what antilock brakes are to automobiles—they provide better control,” then-administrator Joseph Boardman declared in August 2006. ECP, he added, “offers a quantum improvement in rail safety.” The electronic system reduces the distance needed to stop a train by 40 to 60 percent, and performance improves as the train grows longer and heavier.

But most in the industry expect the biggest advantage of ECP to show up as improved efficiency. That’s because there are many different ways to exploit an increase in nimbleness. You can optimize for safety, for speed, or for a little bit of each. Economic considerations will put speed at the top, for while safety is itself an economic consideration—derailments cost money—speed is the more important element.

South Africa’s Spoornet, which is converting all 6500 cars and locomotives that operate on its Richards Bay line to ECP, has reported a 9 percent reduction in round-trip travel time. When coupled with emerging signaling and dispatching technologies, faster stops will further ease congestion on crowded tracks. U.S. railroads desperately need such extra capacity: After consolidation, the industry pulled up a lot of track that seemed redundant at the time and then strained to keep up with a surge of Chinese imports. ECP is also likely to bring big savings in fuel and in maintenance of car wheels and brake shoes, which together could total at least $575 million a year.

These arguments have not yet persuaded railroads to fully embrace the technology. But the FRA makes the rules, and it can bestow its grace on an emerging technology. That’s precisely what happened in 2006, when the agency gave ECP trains operated by BNSF and Norfolk Southern a pass on time-consuming midtrip brake inspections, made largely unnecessary by the constant monitoring. “It sounds like a small thing,” says Nathan Carter, a general manager at Southern Company, an Atlanta-based utility and prominent coal shipper that conducted an expensive early ECP test that ultimately fizzled. “But when you apply it to the railroad broadly, it gives them a great deal of economic advantage”—about $125 million annually, according to Booz Allen.

In October 2007, in the Monongahela Valley, Norfolk Southern began operating the first U.S. freight train braked exclusively by ECP. The BNSF and the Southern Company, whose flirtation with ECP a decade ago came to grief when they tried to overlay the ECP systems on conventional air brakes, now have retrofitted 260 train cars to use only ECP. That’s enough for two trains to deliver Wyoming coal to a power plant in Mississippi; the first began running the rails in January.

The earlier trials that overlaid ECP systems on conventional air brakes stumbled when carriers poached ECP equipment for traditional trains. This time around, the companies have installed stand-alone systems. “That will assure us that we will run them,” says Gerhard Thelen, a Norfolk Southern vice president.

Before this latest test began, Thelen said that his railroad would quickly expand the deployment if the tests worked out. “We basically have to replace the majority of our coal fleet”—over 20 000 cars—”in the next 10 years. If the benefits are there and the [return on investment] is there, we definitely will look towards equipping the majority” with ECP, he says. At the time, Thelen envisioned a decision as early as this year, but Norfolk Southern now says the tests will continue at least through the end of the year. And while Norfolk Southern won’t discuss preliminary results, it upped its order from New York Air Brake from 400 cars to 600 cars. The railroad now runs six ECP-equipped trains, including four over the Pocahontas Division.

Fifty years after the air brake’s invention, railroads still struggled to integrate and master it, according to Mark Aldrich, author of Death Rode the Rails: American Railroad Accidents and Safety, 1828–1965 (Johns Hopkins University Press, 2006). “The Pennsylvania Railroad—no fly-by-night operation—would routinely put men on top of cars as the trains would go down the Allegheny Valley into Altoona, and their job was to assist the air brakes with hand brakes,” Aldrich says. “They did that into the 1920s.”

ECP, however, ought to be quicker to find a place onboard the nation’s freight fleet, predicts Cliff Eby, the FRA’s former deputy and acting administrator. “We’re going to be gathering a lot of data,” he says, “and if the Booz Allen report [estimating conversion costs] is anywhere close in terms of rates of return and payback period, that data is going to be very persuasive.”

Eby argues that many more trains today run as units, with identical cars that stay coupled, as in the Norfolk Southern and BNSF coal trains. Also, it’s not impossible to mix the new system with the old. A hundred years ago, the Interstate Commerce Commission ultimately forced the integration of Westinghouse’s air brake by ordering that 85 percent of the cars in a train be controlled from the locomotive. Railroads complied by simply tacking the straggler cars to the end of the train. The notion lingers in today’s regulations: A train may continue on its way after some brakes fail en route, provided that 85 percent continue to function. In its rule making, the FRA appears to be contemplating how to apply such a provision to ECP.

In the meantime, the FRA has moved to codify the exceptions granted to BNSF and Norfolk Southern. The new rules could be in place by the end of the year. And two more of the seven largest carriers, as well as Union Pacific and Canadian Pacific Railway, were sufficiently impressed by the FRA’s flexibility to order up their own ECP tests this year. The first of two mile-long Union Pacific container trains will begin plying the rails between the Port of Los Angeles and Dallas this summer. When one of those 1600-meter-long trains wants to stop, every one of its cars will stop at the same time, and that will be a relief to everybody, starting with its engineer.

About the Author

Robb Mandelbaum, originally from Iowa, has a thing for trains. Naturally, he had to experience railroad braking for himself, so for this article he left his Brooklyn, N.Y., home for Appalachia and caught a ride with the Norfolk Southern Railway. The route is one of the first where electronically controlled braking has since been deployed. “You’d think 6 hours in a locomotive cab would wear thin after a while,” he says. “But I loved every minute of it.”

Reach Out and Touch Somebody—by Laser

noreply@blogger.com (John Roach) — Thu, 12 Mar 2009 18:09:00 +0000

By John Boyd

PHOTO: JOHN BOYD

11 March 2009—A few years from now, young Jane, returning home from a school trip to the Smithsonian, might excitedly tell her mom, “Guess what? I touched the Hope Diamond today,” while brother John shouts, “That’s nothing! I touched a Neanderthal skull.” These are the kind of scenarios Hiroaki Yano, associate professor in the department of intelligent interaction technologies at the University of Tsukuba, Japan, is working to realize.

Yano, 39, has spent the past 15 years (including obtaining his Ph.D. in engineering) working in the field of haptics, the study of sensing and manipulation of objects through touch. For the past year he has led a research group developing a handheld haptic device for sensing unreachable or untouchable objects and is due to report details of the device next week at the IEEE-sponsored 2009 World Haptics Conference in Salt Lake City.

The prototype system employs a laser range finder to determine the distance to a given object. The data are fed to a computer, where an algorithm calculates the motor torque necessary to move a lever backward and forward in real time on a haptic interface device; the degree of movement corresponds to the changing distance the laser beam measures as it tracks across the surface of the object. By pressing a thumb against the moving lever, the user can feel the reaction force generated by the object and so get a sense of its shape, even down to changes in surface depth as fine as 0.1 millimeter. The device works for a distance up to 1 meter and through glass.

To evaluate how well the device works, Yano had six participants use it see if they could identify which of four unseen objects were placed in front of them: a forward-facing cube, a sphere, a cylinder, or a cube with only one edge facing forward. Each participant was tested four times with each object, for a total of 16 tries. The experiment was carried out with a glass barrier placed in front of the objects.

“The result was amazing,” says Yano. “All participants got the sphere and the cube plane correct every time. Only one participant failed one time to identify the cylinder, and there were two failures in identifying the cube placed edge forward. That’s a 96 percent success rate.”

While Yano is gratified by the success of the tests, there is a lot of work still to be done. He admits the technology is “not suitable for measuring the hardness and weight of an object,” though he speculates that certain remote-scanning technologies, such as hyperspectral imaging used by the mining industry to identify minerals, might be adapted to overcome such deficiencies. Yano wants to refine the haptic interface’s algorithms and mechanical precision to provide more accurate feedback force, and he’d also like to add a stabilization mechanism to eliminate haptic noise caused by movement of the hands. Furthermore, he points out, the device cannot be used to sense an object’s backside.

In addition, the device is a little awkward. It’s roughly as large as a brick and weighs 900 grams, so two hands are required to hold it, and it must be connected to the computer by cable.

“Ideally, we’d like to get it down to the size of a small flashlight,” says Yano. He’d like to make it wireless or use an embedded computer.

The prototype device has just one degree of freedom, so Yano is considering adding a stereo camera sensor, which would provide haptic feedback for several fingers. That addition would make the device more attractive to industry and other fields, he says. However, it would also add to the device’s complexity and cost.

“Now we are not using any special technology,” says Yano. “Should a company be interested in commercializing the device, it would be able to produce a practical prototype in a few months and, I would think, a commercial product in three to five years.”

If that can be done for around $500, Yano thinks that museums and art galleries could replace the notices admonishing patrons not to touch with signs that say “Please Touch the Exhibits.”

About the Author

John Boyd writes about science and technology from Japan. In July 2008 he profiled Atsuo Takanishi, an engineer whose flute-playing robot is just one part of a robotic orchestra he hopes to build.

NASA Planet Hunter to Search Out Other Earths

noreply@blogger.com (John Roach) — Fri, 06 Mar 2009 21:05:00 +0000

By Anna Bogdanowicz

PHOTO: KIM SHIFLETT/NASA

27 February 2009—For centuries, humans have looked up at the sky and wondered if they were alone in the universe. Now we’re one step closer to finding an answer. On 6 March, NASA’s first planet-hunting spacecraft, Kepler, will embark on a three-and-a-half-year journey in search of Earth-like planets outside our solar system. Kepler is the first space telescope capable of discovering such planets orbiting in a distant solar system’s habitable zone—the area in which liquid water, and possibly life, can exist.

“We’re at the threshold of answering questions that date back to the ancient Greeks,” says James Fanson, Kepler project manager at NASA’s Jet Propulsion Laboratory, in Pasadena, Calif. Although astronomers have found more than 330 planets in other solar systems, none of these planets have the size and location believed necessary to support life.

Named for the 17th-century astronomer who discovered the laws of planetary motion, Kepler will orbit the sun instead of the Earth. The craft will focus on about 100 000 stars between the Cygnus and Lyra constellations. (To find this area, in the Northern Hemisphere, look for a triangle of the three brightest stars in the summer sky, which make up the Cygnus constellation. If you make a square with your hands and hold them at arm’s length in the direction of the constellation, you’ll see the area Kepler will explore.) Kepler will find planets using the “transit method,” looking for periodic slight dips in the brightness of stars that can signal a planet orbiting a star.

“Kepler was a technically difficult challenge,” Fanson says. It took nearly 25 years to go from a far-off dream to reality. The mission is the brainchild of Bill Borucki, Kepler’s principal science investigator at NASA Ames Research Center, at Moffett Field, Calif. “Bill proposed the mission several times, but the reviewers were skeptical,” Fanson says. “When an Earth-size planet passes a star, brightness only dims by 84 parts per million. Many thought the technology wasn’t available to measure that, and it took years for scientists to prove it was possible.”

“We didn’t have the detector technology 25 years ago to make those kinds of measurements,” says Riley Duren, chief engineer for Kepler. But in the past decade, charge-coupled devices (CCDs) with the parameters needed for finding other Earths have been demonstrated in the laboratory. Kepler uses the latest detectors but didn’t require inventing new technologies. “We didn’t have to reinvent the wheel,” says Duren. “We just took the best CCDs and made custom versions, and then we built custom electronics and software to get the most out of our system.” The result? A telescope that’s the equivalent of a 95-megapixel camera—the largest ever flown in space—made up of 42 CCDs, each with a bit more than 2 megapixels.

Ball Aerospace & Technologies Corp., in Boulder, Colo., the contractor responsible for building Kepler, began work on the US $500 million mission in 2002. The engineers had to face many challenges: keeping the camera pointed accurately enough so that the stars remained motionless in the images, creating a large field of view to increase the chances of finding stars with orbiting planets, and implementing low-noise electronics to make it possible to read data from the CCDs, according to John Troeltzsch, Ball Aerospace program manager for civil space systems.

“The specification for our pointing accuracy is 9 milliarc seconds of drift over 15 minutes,” Troeltzsch says. That drift is only about 1/56th of the angle resolved by a good ground-based telescope. There aren’t many disturbances in space, except for the solar wind pushing up against Kepler’s photovoltaic panels. To make sure the telescope doesn’t move, four CCDs in the camera monitor the position of 24 stars continuously. If those stars move in the field of view, a control system repositions the telescope.

Building a 1-meter-diameter telescope with a field of view 33 000 times as great as that of the Hubble Space Telescope was no easy undertaking, but that large field of view was absolutely necessary. Planetary orbits are randomly oriented in the sky. In order to see a transit, your line of sight must precisely match up with the plane of the orbit. The more stars you see, the more likely you are to find one with the right orbital plane. The array of CCDs in Kepler’s camera form a focal plane of 900 square centimeters.

Behind that focal plane is a 0.5-meter box containing more than 20 000 electronic components. “The difficulty was designing all those parts to be low noise and maintain performance in a radiation environment,” Troeltzsch says. “It was eight years of putting designs together and seeing if they’d work.” Part of the solution was to operate the camera at –85 °C, which helped reduce the noise.

Once a month, Kepler will turn toward Earth to align a fixed high-gain antenna and transmit its data to NASA’s Deep Space Network (DSN). The DSN is an international network of antennas that supports the agency’s interplanetary spacecraft missions and radio and radar astronomy observations. Scientists at the Ames Research Center will then analyze the results to verify any possible planets. Kepler will also rotate once every 90 days to keep its solar panels directed at the sun.

Planet hunting has been around for more than a decade, but it’s been done mostly from the ground. Kepler isn’t even the first spacecraft to search for planets. In 2006, the French space agency, CNES, launched the Convection Rotation and Planetary Transits (COROT) mission, but it was never expected to find Earth-like planets. Unlike Kepler, COROT orbits Earth, which partly obscures the view of the sky from the craft. This means that COROT can observe a patch of sky for only weeks at a time, not years. “In order to have a firm detection of a planet, we need to see at least three orbits so we can verify that we see a body moving in a fixed orbital period,” Fanson says. “To find planets like Earth, which take a year to go around a star, you need to observe the same stars for three to four years.” Also, compared with Kepler, COROT is much smaller, less sensitive, and has a smaller field of view.

Fanson, Duren, and Troeltzsch say that even if Kepler finds no Earth-like planets, that itself will be a monumental discovery—the fact that planets like ours are rare. But the researchers don’t think that will be the case.

“I’m an optimist, and I hope the galaxy is filled with many Earth-like planets,” Fanson says, adding that the Kepler mission is the highlight of his long career at the agency.

“I’ve been working for NASA for 25 years and have been involved in many exciting missions, including being on the team that fixed the Hubble Space Telescope,” Fanson says. “But this is the most exciting one, because we have the chance to answer a question that has been in the minds of people for as long as we have records.”

$25 billion in electric vehicle loans still waiting for perfect beggars

noreply@blogger.com (John Roach) — Sat, 28 Feb 2009 14:42:00 +0000

from Engadget by Darren Murph

While the Big 3 seem to be visiting Washington on an all-too-regular basis trying to secure funding for future success, $25 billion in loans set aside to promote electric car usage in America has been sitting untouched for nearly two years. As the story goes, the Advanced Technology Vehicles Manufacturing Loan program was established in 2007, but administrations have been toying with ideas about how to use it until present day. Some 75 applications from hopeful companies have been whittled down to 25, but there's no telling how long it'll be before we hear who's getting the cash (and when). Many are irate that this dough is still sitting idle, but we tend to agree with the "let's wait until we find truly remarkably beggars" approach before it's just handed out to those without a viable plan. The takeaway? Electric vehicles may still end up progressing as planned despite the current economy, but only if brilliant plans can cut through miles of red tape.

This Powerful Robot Can Lift Entire Car Frames, Tear Apart Several Humans at Once [Robots]

noreply@blogger.com (John Roach) — Fri, 27 Feb 2009 06:33:00 +0000

from Gizmodo by Jesus Diaz

Leave it to the Germans to invade Poland or create Titan, the world's strongest industrial robot. They can go either way: One day they are in Krakow, and the next their robot lifts a ton.

Titan—which has a payload of one ton and can reach 10.5 feet— is made by Kuka Roboter GmbH. What does this mean: Using a total of nine motors, it can lift five times its own weight, and can manipulate almost anything you can throw at it in a factory. This includes tasks that previous to its release in 2007, required two robots, like raising the frame for an entire car completely unaided. All while maintaining full positioning precision in 3D space, according to the company.

To give you another idea of its power: The second axis of the Titan—powered by two motors—can withstand a static torque of 60,000 newton meters. Any powerful car would only develop 600 Nm. [Kuka]

Jacketed hamsters demonstrate movement-powered nanogenerators

noreply@blogger.com (John Roach) — Fri, 27 Feb 2009 06:20:00 +0000

by Darren Murph, posted Feb 27th 2009 at 12:33AM
Imagine this -- one day, with enough steroids, your pet hamster actually could power your home by just running on its wheel. Georgia Tech researchers have discovered ways to "convert even irregular biomechanical energy into electricity," and it's demonstrating the finding by showing off jacket-wearing rodents that are game to run. According to the institution's Zhong Lin Wang, the minuscule nanogenerators "can convert any mechanical disturbance into electrical energy," which theoretically means that power can be driven by simple, irregular mechanical motion such as the vibration of vocal cords, flapping of a flag or the tapping of fingers. As with most of these university discoveries, there's no telling how soon this stuff will be pushed out to the commercial realm, but at least they've found something to keep the rats busy during the off hours.

Like to say to people that I too own a pocket pet (hamster... or actually we can call him walking battery charger :) ) And while he is mightily cute he is quite annoying... Our hamster loves to start running 5 in the morning and all through the day. He stops running around 7pm for some reason... And now I can use the maniac power!! Muhahaha!!

Microsoft talks open-source love amid TomTom Linux 'war'

noreply@blogger.com (John Roach) — Fri, 27 Feb 2009 06:16:00 +0000

Linux lovers brace for action

By Gavin Clarke in San Francisco

Posted in Applications, 27th February 2009 04:01 GMT

Microsoft has imagined a future where Windows relies on open source, just as community leaders tried to contain the fall out from what some (http://opendotdotdot.blogspot.com/2009/02/has-microsofts-patent-war-against-linux.html) believe could be the start of Microsoft's "war against Linux".

The company's server and tools president Bob Muglia has apparently told a technology conference he believes most of the company's products would use open-source "at some point."

Muglia was speaking at the Stanford Accel Symposium (http://www.accel.com/symposium/venue.html) at Stanford University, California, and his comments were picked up by attendee John Newton, chief technology officer and chairman of Alfreso. "At some point almost all our product will have open source in it," Newton wrote in a Twitter flagged up (http://news.cnet.com/8301-13505_3-10172150-16.html?tag=mncol;txt) by Alfreso fellow Matt Asay.

Microsoft products already contain code licensed under open source. Now it just wants more for Silverlight, Visual Studio 2010, and its Oslo modeling framework. Open source has been seen as a way for Microsoft to enrich and expand the reach of .NET.

But the timing of Muglia's words couldn't have come at a worse moment in Microsoft's long and troubled relationship with the open-source community.

He spoke just as Microsoft filed court papers in the US that accused TomTom of violating its intellectual property with that company's widely used voice-activated car navigation devices. Those devices run TomTom's own brand of GPL and LGPL'd Linux.

Unsurprisingly, Microsoft's attempts to talk-down the broad threat to Linux have been dismissed, and it has fallen to representatives of the open-source community itself to call for calm, while also talking tough in the face of a potential Microsoft threat to Linux.

Linux Foundation executive director Jim Zemlin and Software Freedom Law Center policy analyst Bradley Kuhn both separately moderated their concerns about the case by pointing out that this is a private dispute between Microsoft and TomTom on GPS mapping software.

Kuhn told The Reg people should press on with open-source projects, rather than obsess about what patents might or might not exist in Linux or stop their work on open-source projects through some concern over potential violations or that Microsoft might come knocking.

"Until...they are accused of infringing, there is no reason they should be worried," he said.

"I don’t believe what Microsoft says on this case that it’s not about free and open source software, but at this moment, I don’t see any evidence this patent reads on free and open source software. Patents get narrowed and invalidated during the patent litigation process all the time."

Zemlin blogged (http://www.linux-foundation.org/weblogs/jzemlin/2009/02/26/note-on-microsoft-tomtom-suit-calm-down-hope-for-the-best-plan-for-the-worst/) that people should calm down, hope for the best, and plan for the worst. To that end, the Linux Foundation said it's watching the situation and is ready to mount a defense of Linux should the need arise.

"The Linux ecosystem has enormously sophisticated resources available to assist in the defense of any claim that is made against Linux," Zemlin wrote.

"We do not feel assumptions should be made about the scope or facts of this case and its inclusion, if any, of Linux-related technology."

The claim that has people concerned involves TomTom's Linux using an implementation of FAT to add file system support for long and short file names, memory management for flash, and for connecting devices. The question is whether TomTom misused Microsoft's patented version of FAT32 and VFAT - which it's been licensing to third parties - or whether it employed a different implementation of FAT instead. FAT is commonly used in consumer devices, such as digital cameras, when connecting to PCs.

The TomTom picture is complicated by the fact it runs a mix of Linux and proprietary software. You can get Microsoft's filings here (http://regmedia.co.uk/2009/02/27/tomtom1.pdf) and here (http://regmedia.co.uk/2009/02/27/tomtom2.pdf) (both PDFs).

The case is ironic, given TomTom was actually found to be in violation of the GPL in October 2004 by the GPL Violations Project. TomTom subsequently agreed to make the modifications it made to Linux available online as part of the Linux Kernel.

TomTom US refused to comment on the case, but a spokesperson at its head-quarters on the Netherlands told (http://money.cnn.com/news/newsfeeds/articles/djf500/200902260425DOWJONESDJONLINE000552_FORTUNE5.htm) Dow Jones TomTom would "vigorously defend" itself. ®

Toshiba shows off 32nm NAND flash chips, promises to go smaller

noreply@blogger.com (John Roach) — Wed, 25 Feb 2009 18:12:00 +0000

from Engadget by Donald Melanson

32nm NAND flash memory may not seem like a huge leap over some of the current 34nm chips out there, but Toshiba seems to be able to appreciate the little things in life, and it's certainly found plenty to boast about with its latest chips here. Perhaps most notably, the company apparently didn't make any major changes from its previous 43nm chips in terms of device structure, with the exception of one "major improvement" to the circuit that was made to overcome the "extremely small" write margin. The new 32nm chips also pack the same 32-gigabit (or 4GB) capacity as those aforementioned 34nm chips, which should let folks cram a bit more storage into the same small space. Better still, Toshiba says volume production of the chips should begin as soon as September of this year, and it's apparently already aiming to mass produce some chips in the 20 to 30nm range by late 2010 or 2011.

It’s wrong to wish on space hardware

noreply@blogger.com (John Roach) — Wed, 25 Feb 2009 18:08:00 +0000

from RealClimate by gavin

A number of satellite related issues have come up this weekend: The NSIDC reminded us that satellite sensors are (like all kinds of data) not perfectly reliable and do not last forever. Two satellites collided by accident last week, littering the orbit with dangerous amounts of debris. In San Diego this weekend, I was fortunate enough to attend a meeting with some of the Apollo astronauts and some of the scientists involved in Cassini and the Mars Phoenix missions. And yesterday morning we heard that the Orbiting Carbon Observatory mission launch failed to insert the satellite into orbit, and it is presumably measuring carbon dioxide somewhere at the bottom of the Southern Ocean. Coincidentally, when it came up on the news, I was in a meeting with one of the scientists who had been working on setting up a climate model to assimilate the OCO data in order to pin down the carbon sinks.

All of these events have served to remind me at least, that although the space age is 50 years old, we are a long way from the point where we can take our ability to launch and control off-planet machines for granted. Getting into space was, and remains, a tremendous challenge. This makes the successes we've had all the more incredible, and a testament to the hard work the engineers and scientists do over many years before a launch to give the missions the best chance of success.

For the climate-related satellites/instruments - SSM/I for the sea ice, OCO for high-precision CO₂ concentrations - there is some redundancy with other existing missions. The JAXA AMSR-E sensor can still be used for sea ice extent (and indeed, SSM/I is still sending enough data back to construct 3 day mean pictures). For CO₂, the substitutes are slightly orthogonal - the Japanese Ibuki satellite launched last month will measure CO₂ but with a very different footprint than OCO would have used, and the AIRS instrument on Aqua has recently been used to produce a timeseries of mid-troposphere CO₂ concentrations since 2004. Nonetheless, both of these other missions should provide some of the information that was anticipated from OCO - though not at the spatial resolution envisaged.

It's worth discussing a little what OCO was going to be useful for. It wasn't because we don't know the average amount of CO₂ in the atmosphere and how much it's increasing - that is actually pretty well characterised by the current station network (around 386 ppm growing at ~2ppm/year). However, the variations about the mean (tens of ppm) have a lot of extra information about the carbon cycle that are only coarsely resolved. The measurements would have been from nearer the surface than the AIRS data, and so closer to the sources and sinks. You would have been able to see point sources quite clearly and this would have been a good check on the national inventories of fossil fuel use, and may have been useful at constraining the rather uncertain deforestation contribution to the anthropogenic carbon dioxide sources. More importantly, the OCO data combined with inverse modelling might have helped with constraining the terrestrial sinks. We know they exist from residual calculations (what's left over from knowing how much we are adding, and seeing how much is in the air and what is in the ocean), and they've mainly been associated with boreal ecosystems from the inverse modelling done so far, but there are quite large uncertainties (see 7.3.2 and fig 7.7 in AR4 Chp. 7). The Ibuki and AIRS data will help with this same issue, but OCO data would have been somewhat orthogonal.

Another important consequence perhaps, is that the upcoming Glory mission may be further delayed since it is slated to use the same launch vehicle as the one that malfunctioned for OCO. Glory has had a troubled past, surviving a number of bouts with near-cancellation, but was basically all set to go in June. This is a big deal because Glory will carry one new instrument (an aerosol polarimeter) that has the unique ability (among sensors flying today) to distinguish between aerosol types in the atmosphere. Currently, aerosol remote sensing can retrieve the total aerosol optical depth, with some ability to discriminate between fine particles and more massive ones, but it can't tell the difference between sea salt and sulphates, dust or soot. This has been a huge problem for aerosol modellers since it is hard to evaluate simulations of each individual aerosol type (and which consequently are all over the place (AEROCOM)). A polarimeter detects the changes in polarisation associated with the aerosols which differs greatly between the different types. The second instrument on Glory is a total irradiance monitor (TIM) which is needed to prevent a gap from forming in the satellite observations of the sun should the current (6 year old) TIM on the SORCE satellite start to falter.

Ironically, space on satellites is at a huge premium. There are always dozens of possible candidate instruments that could be flown and ensuring that the right mix of monitoring and experimental measurements get made is very hard. For instance, the group behind the polarimeter on Glory were trying to find space on a suitable satellite for years before the Glory mission was resurrected.

All this to say, that while the OCO failure will be devastating for the teams that worked on the mission, the relatively high chances of a complete failure are part of the price to be paid for working on satellite missions. Fortunately, OCO was a relatively cheap proof-of-concept mission and so it might someday get another day in the sun.

As new term starts updates gets slower...

noreply@blogger.com (John Roach) — Fri, 06 Feb 2009 16:13:00 +0000

The term will be starting Monday... My new schedule is up. Any tech news updates and other related posts would be slow to come by. My laptop is all ready for the term. I installed (or going to install it depends on when you read this) Matlab Linux. And some neat Electronics programs. Got to go...

Peace

Personal blog becomes a little more personal

noreply@blogger.com (John Roach) — Sun, 25 Jan 2009 20:44:00 +0000

If you have been reading my posts regularly you would have seen that I was toying with an idea of putting a login page over my personal blog. Didn't really feel comfortable with everyone reading my personal blog. So when you enter my blog just register. It will be fun. Surprises await for those who register. Well, that's about it.

Yeah yeah yeah!!! Low powered quad core chips!!

noreply@blogger.com (John Roach) — Tue, 20 Jan 2009 16:06:00 +0000

Original URL: http://www.channelregister.co.uk/2009/01/20/intel_price_adjustments_launch/

Chip giant whips out low-power quad-core CPUs

Intel cuts prices too

By Tony Smith

Posted in PC Builder, 20th January 2009 10:52 GMT

Intel has rolled out some new CPUs and cut the prices of old ones.

The chip giant's desktop product list now includes the Core 2 Quad Q9550s, Q9400s and Q8200s. The suffix indicates they're all low-power version of existing quad-core chips, each sporting a reduced TDP of 65W, down from 95W.

Clocked at, respectively, 2.83GHz, 2.66GHz and 2.33GHz, the CPUs all sit on a 1333MHz frontside bus. They contain 12MB, 6MB and 4MB of L2 cache, and are priced at $369, $320 and $245 when ordered in batches of 1000.

The price cuts - of between 16 per cent and 40 per cent - take the 95W Core 2 Quads down to below those prices, leaving us in the unusual situation of a 3GHz Q9650 costing less than a slower, lower-model-number part, the Q9550s.

Intel also introduced the 2.93GHz Core 2 Duo E7500 - 3MB L2, 1066MHz FSB, $133 - and the 2.8GHz Pentium Dual Core E5400 - 2MB L2, 800MHz FSB, $84.

Both the Core 2 Duo and the Pentium Dual Core lines also experience downward price adjustments, of up to 15 per cent and 24 per cent, respectively. ®

Dutch Study Says Filesharing Has Positive Economic Effects (so says news on Slashdot)

noreply@blogger.com (John Roach) — Mon, 19 Jan 2009 18:17:00 +0000

Slashdot writes

An anonymous reader writes "In a study conducted by TNO for the Dutch government the economic effects of filesharing are found to be positive. According to the 146 page report (available for download, but in Dutch) filesharing is good for the prosperity of the Dutch: with filesharing more media are available, even though this costs the media industry some profit. One of the most noticeable conclusions is that downloading and buying are not mutually exclusive: downloaders on average buy just as much music as non-downloaders, but they buy more DVD's and games then people who don't download. They also tend to visit more concerts and buy more merchandise."

All I can say is yeah right! I mean why should someone buy a media when you can get it for free. I mean now they have all these DivX players and all so playing it on TV is less of a problem. And as for quality I have seen many High Definition quality illegal media on the net. Sorry Dutch government researchers just don't kid yourselves.

Peace!!

And as the new year draws near...

noreply@blogger.com (John Roach) — Wed, 31 Dec 2008 16:13:00 +0000

Hello people,
I hope all is well and going good. I must say so far it's been a good year for me. With it's ups and downs the has been kind to me. However I know it hasn't been kind to most of the world with it's floods, earthquakes, disease, unemployment's, financial crises and wars. I hope this year be a good year full of hope and happiness where good deeds are the key to success instead of stepping and back stabbing others. I hope this year will be a easy one for all those who earn their money with the sweat on their brow and dirt in their hands and palms. And I hope this year would be full of love, light, hope and happiness.

Turkey lost Yücel Kalınyazgan

noreply@blogger.com (John Roach) — Tue, 23 Dec 2008 16:26:00 +0000

A sad day indeed. I was deeply saddened to hear about the death of Yücel Kalınyazgan. He died on the 22nd of December. I know how much the school will miss Yücel Kalınyazgan. He was a fine leader and a good educator. I wish his family condolences. Turkey has lost one of its good men. There will be a prayer session on the 25th ( December ) dedicated to him at the Kocatepe Mosque in Kızılay after the noon prayer.

A quick breath...

noreply@blogger.com (John Roach) — Tue, 16 Dec 2008 19:17:00 +0000

Hi to all. I know I haven't been able to post up new updates for a time but I really didn't have the time. And to the tech news.

It seems my Fedora 10 post raised a head ?? ( or was it just a random poster? ) I will be field testing Fedora 10 on my SONY VAIO VGN-FS950 Laptop soon. I am just hoping for the best. ( Meaning I wish these freaking FN keys could just work... )

I started a new Software Project. A PHP based online ninja game. There seem to be 3 ninja games in the works. However all of them require you to be online 24/7 which I know not a lot of people can do. Any ideas for concept story and such are welcomed. Who knows you may be a part of a Facebook/Google-like-online-craze. Just e-mail me. I will be writing most of the code. I am thinking of making it Open-Source.

Talking of a Secure ISP server. Royal-pingdom.com gives us the best ISP place ever. An old nuke shelter.
The photo came from Royal Pingdom @ royal.pingdom.com

A ISP underground strong enough to withstand a near miss nuke. What safer environment one can work in?

Anyway people this all for now...

Peace!

New site design...

noreply@blogger.com (John Roach) — Sat, 22 Nov 2008 22:14:00 +0000

Yay... A new site design... This time it all belongs to me... Meaning no "This design belongs to ... " . I will be adding a footer to the page. Now you can access my stories.

Aaaand new more stuff... Software Projects!! Which you can reach from http://johnroach.info/index.php?submit=Projects&submenu=software

I hope you like this design. It is simple and robust...

Peace !

Fedora 10 is coming soon

noreply@blogger.com (John Roach) — Fri, 14 Nov 2008 09:17:00 +0000

For those who don't know. Fedora is a Red Hat Linux based OS. And it's free. I have been using it on my laptop ( SONY VAIO VGN-FS950 ) since Fedora 8 was out. Fedora 8 wasn't a very good choice for my laptop. It had some glitches. But Fedora 9 was just GREAT!!! And now Fedora 10 is coming out. I just can't wait. I hope it has lots of eye-candy and desktop-gizmos.

Visit solder by numbers

noreply@blogger.com (John Roach) — Sun, 09 Nov 2008 18:15:00 +0000

A new website for electronics people. A site that allows you to design and use circuit design easily. Visit http://www.solderbynumbers.com/ for more info. I think you would like it.