Thursday, May 19, 2011

Final Exams

Hello all!

Unfortunately, final exams are around the corner. In fact, I have one tomorrow and three final exams next week.

You have probably noticed a lack of posts and this is because I am studying hard for my exams.

Hopefully you'll look forward to some very interesting posts when I get back!

Thank you!

Sunday, May 8, 2011

Solve Complex Problems With Unused Computing Power (using BOINC)

Imagine if everyone's computers were combined together to create one big network of computing strength more powerful than any supercomputer on earth. That's what BOINC (Berkeley Open Infrastructure for Network Computing) does, and you can be a part of it today.

Many people are oblivious to the fact that there is quite a lot of computing power going unused each and every day. The fact of the matter is, nearly everyone has a desktop computer or a laptop computer these days. However, how often do we put our actual computing power to use? Most of the time we are not using our computer for very demanding work--sometimes we will render a video here and there, play a few games, or do some other work that actually uses our computing power.

Folding@home simulates protein folding using distributed computing. It currently operates at above 7 native petaFLOPS, with a large majority of the performance coming from GPU and PlayStation 3 clients. In comparison to this, the fastest standalone supercomputer (non-distributed computing) in the world (as of November 2010, Tianhe-I) peaks at approximately 2.56 petaFLOPS.
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Now with this being said, there is a large amount of computing power that we can still tap into. Imagine if everyone's computers were combined together and synchronized together to take on even the most challenging computational problems, such as protein folding or galaxy formation. That is what the BOINC project does (Berkeley Open Infrastructure for Network Computing).

How it works is simple. Say your computer is idle for an hour or two a day, or you're simply surfing the internet and not using your compute for much more. Well, in that amount of time you can leave BOINC running in the background and it would have completed several work units (WU's) which will be sent to the central server and then used in conjunction with thousands of other work units to observe the characteristics of protein folding (crucial in cancer research--folding@home), galaxy formation (MilkyWay@home), mathematical problems (abc conjecture in number theory--ABC@home), and much more.

This way, you are tapping into the unused computing power of your computer and contributing to the advancement of mankind at the same time. It's a wonderful way of utilizing unused resources in our world for advanced research.

MilkyWay@home renders complex N-body simulations which are used to generate 3D dynamic models of stellar streams near the Milky Way galaxy.
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Many computer enthusiasts also use the BOINC platform to test their computer for speed and performance, since it uses up every bit of computing power available, it is a good stress test for overclocks and gamers. However, the beauty of BOINC is that it is simple to use and can be used by anyone--computer savvy or not.

Take for example folding@home (though not technically a BOINC project, it is distributed computing). It is a single download which you install and then simply run to compute work units. Many people also join teams and organizations to see who has the most points or work units. It turns into a competition for the benefit of all!

The unique feature of BOINC is that it can attach not only one project, but nearly an unlimited amount of distributed computing projects. It is the most popular platform under which many distributed computing projects thrive.
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If you are interested in participating in the BOINC project for distributed computing, you can start today. There are many projects available. In some instances you can even use your graphics card to do work that would normally take hours--in a few minutes (for those of you with powerful graphics cards out there).

Some popular distributed computing/BOINC projects are:

folding@home: designed to perform computationally intensive simulations of protein folding and other molecular dynamics (MD), and to improve on the methods available to do so (though not technically a BOINC project, it is distributed computing).

MilkyWay@home: attempts to generate highly accurate three-dimensional dynamic models of stellar streams in the immediate vicinity of our Milky Way galaxy.

SETI@home: to analyze radio signals, searching for signs of extra terrestrial intelligence, and is one of many activities undertaken as part of SETI.

LHC@home: to help maintain and improve the Large Hadron Collider (LHC), which became active in September 2008.

PrimeGrid: project for searching for prime numbers of world-record size. project to investigate and reduce uncertainties in climate modelling.

Astropulse: to search for primordial black holes, pulsars, and ETI.

Einstein@home: searches through data from the LIGO detectors for evidence of continuous gravitational-wave sources, which are expected for instance from rapidly spinning non-axisymmetric neutron stars.


Personally, I am currently active on MilkyWay@home and folding@home and plan to try out many other distributed computing projects soon!

Let me know which project you plan to join in a comment!

Thursday, May 5, 2011

Which Headphones To Buy? - Part II: Sound Signature

Ever get confused by the language that wine connoisseurs use when describing high-priced wines? Terminology for niche products such as expensive wines, computers, and even headphones are indeed necessary to describe subtle but important differences; many users unaware of such attributes may overlook these nuances.

Headphones are one of these products. Every headphone has a different sound signature, almost like a wine has a unique taste regardless if it falls into larger categories such as Red Wines or White Wines.

There is a lot of jargon within the audiophile community involving sound signatures in headphones, but today I wish to clarify some of these terms in order to make it easier for you to purchase the headphone that is right for you.

Many headphone sound signatures can be compared through a Frequency Response Curve. However, this does not ultimately reveal what the sound signature of the headphone is--it is more of a glimpse into how the headphone may sound.

Headphones fall into three large categories, after which other attributes follow a hierarchical structure or a branch structure. All of these main categories have strengths and weaknesses.

These three main categories are the following:

1) A "Colored" sound; this sound signature means that the headphone is taking in the audio signal and is manipulating what the audio input is telling the headphone. The end result is either a bassier sound, a "brighter" sound which emphasizes vocals more or instruments more, or simply a "clearer" sound. Colored headphones tend to "Wow" at first but may reveal flaws such as a muddy bass response or a lack of a realistic vocal range. However, colored headphones are usually the most popular headphones due to their initial "Wow" factor.

Some examples of colored headphones are: Bose QuietComfort, Dr. Dre Beats, Skullcandy headphones. Personally, I do not enjoy colored headphones at all.

2) An "Analytical" sound; this sound signature is usually associated with a large amount of clarity in the headphone. Even the tiniest details and nuances can be heard, such as pages being turned in a classical music symphony, or the sound of air rushing through the vocal chords of a singer before words come out. However, this analytical sound tends to be weak on a "musical" presence. Cohesiveness of the audio is sometimes a flaw in analytical sound signatures.

Some examples of analytical headphones are: Etymotic ER-4P, Shure SRH840. I enjoy analytical headphones from time to time.

3) A "Neutral" sound; this sound signature is what audiophiles usually lean towards. A neutral sound signature takes the audio signal and barely touches it. What the headphone strives towards is an accurate reproduction of what was recorded, not bass boost or a treble boost. Neutral headphones are usually harder to tune properly by the manufacturer due to the ear's natural tendency to hear different frequencies at different volumes. A decent neutral headphone will have a very clear sound and a "musical" enjoyment to it. However, neutral headphones are usually said to be "uninvolving" or not enjoyable due to there being no "fun factor" in listening to the headphone.

Some examples of neutral headphones are: AKG K702 , Sennheiser HD600 & HD800, Beyerdynamic DT-880. I am a big fan of neutral headphones and use them often.

The Etymotic ER-4P is famous for its analytical sound signature and extremely detailed sound quality.

Again, all of these sound signatures have strengths and benefits. However, after listening to many headphones it is easier to tell which sound signature suits your tastes. For example, I prefer neutral headphones with a touch of an analytical sound signature and a slightly warm midrange.

If you have the opportunity to visit a Head-fi meet where users bring many headphones and amplifiers, you will have an easier time understanding which sound signature is right for you. usually has several headphone meets every year, and some may be very close to your location! (For me, there was one in New York City so it was right where I was located). If you can't go to a head-fi meet, then it is good to try out many headphones at a department store or an electronics store. Usually a big name manufacturer like Sennheiser has its own "house sound" which tends to remain the same across their different models, changing slightly. So by trying out many different brands, you will expose yourself to different "house sounds" and it will then be easier to make your final decision.

Certain genres also tend to have good synergy with specific sound signatures. For example, Pop music tends to pair well with Colored Sound Signatures or Analytical Sound Signatures. Jazz and Classical tend to pair well with Neutral and Analytical Sound Signatures. Hip-Hop tends to pair well with Colored Sound Signatures. However, a very good headphone will usually sound OK with any genre, regardless of the headphones' sound signature. It may not make that genre sound as good as it can be, but it will produce a sound that is certainly satisfactory.

The Sennheiser house sound is enjoyed by many. It is described as a "laid back" sound signature with a warm mid-range and a deep bass response that is not overpowering. The Sennheiser HD 650, pictured above, requires a good headphone amplifier to bring out its true potential.
Source: WikiMedia Commons

It is important to note that so far we have only covered the three major categories for headphone sound signatures. Each of these categories can be further broken down more precisely in terms of how they actually produce sounds in certain frequency ranges, but I will save that for a future post.

To summarize, every headphone has a unique sound signature that tends to fall into one of three main categories. These categories are: colored, analytical, and neutral. Depending on your tastes, some of these sound signatures will sound OK to you will others may not be satisfactory. However, a large portion of this depends on what genre of music you are listening to on the headphone, as well as your personal expectations of the sound.

Nevertheless, if you do plan on purchasing headphones, it is well worth your time to research and try out different headphones to find out which sound signature suits you--it will save you money, time, and the frustration involved in purchasing the right headphone for you.