John Roach » Old posts

Playing cards is fun

John Roach — Sun, 22 Apr 2012 20:23:19 +0000

For some reason I remembered my probability class back in the university. The class was fairly fun while also being an integral part of another un-fun class telecommunications. The calculation of the probability getting a straight in poker is being used in many ways in telecommunications. This brings another facet of playing cards doesn’t it? Playing cards can sometimes be fun.

Giving Small Robots New Ways to Move (IEEE)

John Roach — Fri, 23 Oct 2009 06:57:17 +0000

I always thought that there should be smaller robots. We do have the technology. Look at your PDAs,IPhones and HTC model telephones. All are actually sophisticated computers. Why not use this technology to make smaller bots? And while making them smaller why not make the so they can move easily through. After all a cockroach can go to places where you would usually say “How in the hell did it get up there?”.

These 10 years are about bio-robots. By tagging the name of bio-robots I mean robots that act and move like insects and other simple life forms. And if we can perfect our way in constructing and programming such robots we will find out how to make androids!! ( Probably going too far.) I hope to maybe get my hand on some part to make my own. But I just really don’t have the time .

Installed Fedora 11 on Compaq Presario CQ50 (Dual-boot/Vista)

John Roach — Thu, 22 Oct 2009 09:13:35 +0000

Fedora. My first love in linux started with Fedora and now I realized this love was not because of some novelty. It was actually because it is easier to use.(As a developer.) So I simply installed Fedora 11 over Ubuntu 9.04 it worked like a charm tough I had to do couple of tweaks. The first tweak was the adding the recovery hard-disk of Vista to the boot menu. No problem there just a simple grub.conf editing was done as below ;

# grub.conf generated by anaconda # # Note that you do not have to rerun grub after making changes to this file # NOTICE: You have a /boot partition. This means that # all kernel and initrd paths are relative to /boot/, eg. # root (hd0,2) # kernel /vmlinuz-version ro root=/dev/mapper/vg_johnsfedorabox-lv_root # initrd /initrd-version.img #boot=/dev/sda default=3 timeout=15 splashimage=(hd0,2)/grub/splash.xpm.gz #hiddenmenu title NCTUns (2.6.28.9-nctuns-20090901) root (hd0,2) kernel /vmlinuz-2.6.28.9-nctuns-20090901 ro root=/dev/mapper/vg_johnsfe$ initrd /initrd-2.6.28.9-nctuns-20090901.img title Fedora (2.6.30.8-64.fc11.i586) root (hd0,2) kernel /vmlinuz-2.6.30.8-64.fc11.i586 ro root=/dev/mapper/vg_johnsfedor$ initrd /initrd-2.6.30.8-64.fc11.i586.img title Fedora (2.6.29.4-167.fc11.i586) root (hd0,2) kernel /vmlinuz-2.6.29.4-167.fc11.i586 ro root=/dev/mapper/vg_johnsfedo$ initrd /initrd-2.6.29.4-167.fc11.i586.img title Vista rootnoverify (hd0,0) chainloader +1 title Vista-backup rootnoverify (hd0,1) chainloader +1

See simple right? And then I just had to install the usual suspects such as ; flash-plugin, vlc, eclipse, netbeans, mysql, apache2, php5, nctuns and so on. However the thing with Fedora is that all of this is very easy. So if you have any problems with installing Fedora 11 on a Compaq Presario CQ50 just yell!

The site has been updated

John Roach — Tue, 20 Oct 2009 08:52:56 +0000

Yes, at last. Free of Blogger/Google. I won’t be blocked!! Thanks to Turkish blocking sites I have decided to carry EVERYTHING to my OWN host. And voila! What you see is what has happened.

I am using WordPress for people who are wondering and I know the theme is a little dark. But it is simple and I like simple.

And just to wet your appetites I shall post a tech related video.

iRobot’s Shape-Shifting Blob ‘Bot Takes Its First Steps (IEEE News)

John Roach — Wed, 14 Oct 2009 04:42:00 +0000

POSTED BY: Anne-Marie Corley // Tue, October 13, 2009

This is by far one of the coolest and weirdest robot prototypes we at IEEE Spectrum have ever seen.

Meet iRobot’s soft, shape-shifting robot blob. It rolls around and changes shape, and it will be able to squeeze through tiny cracks in a wall when the project is finished.

(Skip the first 1:50 minutes of the video above to see the blob in action.)

Researchers from iRobot and the University of Chicago discussed their palm-sized soft robot, known as a chemical robot, or chembot, at IROS yesterday. It’s “the first demonstration of a completely soft, mobile robot using jamming as an enabling technology,” they write in a paper.

The concept of “jamming skin enabled locomotion” is explained quite nicely in the video. The polymer used for the bot’s stretchy skin is off-the-shelf silicon two-part rubber.

By controlling the parts of the blob that “inflate,” the researchers can make it roll.

The video shows the project as it was about a year ago. The current stage has a bit different design and is moving toward the ability to include sensors or even connect different blobs together, but those details are sketchy.

When asked about the usefulness of such a bot, iRobot researcher Annan Mozeika promptly answered, “to squeeze into small holes.” And who wants to do that? DARPA, of course. End of questions.

This is how we will look to aliens (do they even exist?)

John Roach — Fri, 18 Sep 2009 07:13:00 +0000

Quantum Chip Helps Crack Code (IEEE News)

John Roach — Fri, 11 Sep 2009 07:02:00 +0000

BY ANNE-MARIE CORLEY // SEPTEMBER 2009

Photo: Jonathan Matthews/University of Bristol

3 September 2009—Modern cryptography relies on the extreme difficulty computers have in factoring huge numbers, but an algorithm that works only on a quantum computer finds factors easily. Today in Science, researchers at the University of Bristol, in England, report the first factoring using this method—called Shor’s algorithm—on a chip-scale quantum computer, bringing the field a tiny step closer to realizing practical quantum computation and code cracking.

Quantum computers are based on the quantum bit, or qubit. A bit in an ordinary computer can be either a 1 or a 0, but a qubit can be 1, 0, or a ”superposition” of both at the same time. That makes solving certain problems—like factoring—exponentially faster, because it lets the computer try many more solutions at once. The race is on to find the ideal quantum computer architecture, with qubit contenders that include ions, electrons, superconducting circuits, and in the University of Bristol’s case, photons.

MIT professor Seth Lloyd, who has been researching quantum computing and communication systems since the early 1990s, says that ”optical methods [using photons] have a long way to go before being useful.” But, Lloyd adds, the Bristol experiment demonstrates that the components for optical quantum computing can be squeezed onto a chip, which is an important step forward.

Shor’s algorithm was first demonstrated in a computing system based on nuclear magnetic resonance—manipulating molecules in a solution with strong magnetic fields. It was later demonstrated with quantum optical methods but with the use of bulk components like mirrors and beam splitters that take up an unwieldy area of several square meters.

Last year, the Bristol researchers showed they could miniaturize this optical setup, building a quantum photonic circuit on a silicon chip mere millimeters square. They replaced mirrors and beam splitters with waveguides that weave their way around the chip and interact to split, reflect, and transmit light through the circuit. They then injected photons into the waveguides to act as their qubits.

Now they’ve put their circuit to work: Using four photons that pass through a sequence of quantum logic gates, the optical circuit helped find the prime factors of the number 15. While the researchers showed that it was possible to solve for the factors, the chip itself didn’t just spit out 5 and 3. Instead, it came up with an answer to the ”order-finding routine,” the ”computationally hard” part of Shor’s algorithm that requires a quantum calculation to solve the problem in a reasonable amount of time, according to Jeremy O’Brien, a professor of physics and electrical engineering at the University of Bristol. The researchers then finished the computation using an ordinary computer to finally come up with the correct factors.

Of course, says O’Brien, ”a smart schoolkid could tell you [the answer] in a few seconds.” To be really useful, he says, ”what we’d need is a quantum computer that has millions of qubits, to solve problems that are genuinely hard to solve otherwise.”

That quantum factoring machine is decades away, but in the meantime chip-scale optical architectures like those of the Bristol team could help in applications like quantum key distribution, which guarantees secure communication based on the laws of quantum mechanics rather than on the mathematical difficulty of factoring. Or they could be used to simulate quantum systems in physics experiments, which might require just hundreds of qubits instead of thousands or millions.

Photo: Jonathan Matthews/University of Bristol

”We know 3 times 5 is 15,” says University of Maryland quantum computing expert Christopher Monroe, but this experiment ”has promise for developing something that could tell us the answer to something we don’t know.”

MIT’s Lloyd is not convinced that the technology is scalable. The real trick, he says, will be to develop a self-contained method that measures the photons, reads the results, and finds the factors of huge numbers without dipping back into classical computation or knowing the answer ahead of time. That’s the ”tough technological problem that no one has any idea how to solve,” Lloyd says, although he believes it’s ”not against the laws of physics.”

O’Brien, however, says that only the hard part needs to be done on a quantum computer, which will likely be a highly sophisticated device and in much demand. ”You wouldn’t waste its time with classical computations,” O’Brien says. ”If the other bits are easy, why do them on a quantum computer?”

The Bristol group next aims to build larger, more sophisticated quantum optical circuits, with more waveguides packed on the chip, in addition to more-efficient single-photon generators and detectors. That will push them toward a scaled-up system that might, decades hence, break math-based encryption codes using millions of qubits.

Flexible Inorganic LED Displays ( IEEE News)

John Roach — Fri, 04 Sep 2009 04:22:00 +0000

by John Rogers

Photo: D. Stevenson and C. Conway/Beckman Institute/University of Illinois

21 August 2009—Organic light-emitting diodes, or OLEDs, are seen as the successor to liquid crystal technology for small, pixel-dense displays like the ones in laptops, smartphones, and digital cameras. Conventional inorganic LEDs, which are poised to put incandescent and fluorescent lightbulbs out to pasture, have never been in the race, because the processing techniques used to make them don’t allow scaling down to the resolution required for a pocket-size display.

But a group made up of researchers based in Illinois and Beijing reported yesterday in the online edition of Science that they have developed methods for creating, assembling, and connecting inorganic LEDs on a flexible substrate. This will finally allow the miniaturization of the technology, which beats OLEDs in brightness, energy efficiency, durability, and moisture resistance.

The technology was developed as part of a research project funded by the Ford Motor Co., which envisions many possible automotive applications for thin, flexible lighting systems. Among these are instrumentation gauges that can be placed just about anywhere.

The researchers started by growing a four-layer semiconductor sandwich with all the makings of an inorganic LED. They did this atop a layer of aluminum arsenide which itself coated a gallium arsenide substrate. Using a combination of photolithography, chemical etching, and a proprietary polymer process, they turned the wafer into an array of 100-by-100-micrometer LEDs loosely attached to the gallium arsenide by polymer anchors.

The team then used an automated printing tool composed of a soft rubber stamp with embossed features that act as suction cups. The cups attach to the tops of the LEDs, and when the stamp is peeled away, the polymer anchors break. The stamp then deposits the LEDs on a glass substrate coated with an adhesive strong enough to overcome the suction force.

Photo: D. Stevenson and C. Conway/Beckman Institute/University of Illinois

The researchers say the device can also be printed onto flexible substrates instead of glass to cover objects with curves or corners. Rogers has done pioneering work in making flexible electronic circuits and has founded a firm—Semprius, in Durham, N.C.—to commercialize it.

Displays produced from this printing process are highly efficient, says Rogers, who explains that you can achieve the same brightness and image clarity with a lot less material than that used in OLEDs. The 16-by-16 array the team produced has a total surface area of 325 square millimeters. The LEDs together take up less than 1 percent of that real estate, he says. And the LED devices can be made even smaller than the 100-µm-edged version; the techniques the team used are compatible with devices as small as 10 µm on a side.

However, such small LED sizes do not improve picture quality in any way, because the human eye can’t resolve anything smaller than about 100 µm across, says Rogers. ”This is all about making the devices lighter and cheaper,” he says. As a bonus, such displays would be almost completely transparent—and well suited for another automotive need: inexpensive head-up displays.

And thus man landed on the moon…

John Roach — Thu, 16 Jul 2009 11:59:00 +0000

I hope this video makes you remember what it was like to explore an unknown place.

Visit msnbc.com for Breaking News, World News, and News about the Economy

Analysis of openSUSE 11.1

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!