Although I have not made any posts in a while, I still continue to follow a large number of blogs. So, just how large you may ask?

The Australian didgeridoo or yidaki is a simple wind instrument, yet a good player can coax from it a variety of timbres greater than that of many an orchestral instrument. It can produce a huge variety of different timbres, despite it usually playing only a single note. A study of the vocal tract and lip contortions necessary for this feat tells us a lot about how music is made.

To understand this phenomenon, researchers led by Joe Wolfe of the University of New South Wales in Sydney simultaneously measured the sound produced by the didgeridoo and the acoustic impedance of the player’s vocal tract. What they found was that a skilled player alters the acoustics inside their mouth to set up strong resonances at certain frequencies. Players enhances certain frequencies while inhibiting others, much as different vowel sounds are produced by adopting different positions for the tongue and vocal cords. In other words, experienced players are using their glottis to accentuate the instrument’s tonal variation.

Skilled didgeridoo players do this subconsciously, Wolfe says: “None of the players to whom we’ve spoken is aware of it.” But the creation of these characteristic frequency bands, called formants, is what gives their playing expression and variety. “It’s easy to make a basic sound,” Wolfe says. “Then you have to learn circular breathing. Learning to make strong formants takes a while. Other techniques involve vocalizing and playing at the same time: one gets interactions between the vibrations from the lips and from the vocal cords.”

via news@nature.com, PhysOrg, Acoustics: The vocal tract and the sound of a didgeridoo (Abstract)

Why I blog this? Over the past few months I have been learning about as much as I can take in about acoustics, synthesizers, and music in general, so this article instantly grabbed my attention. Also, a good friend of mine has been playing didg for a number of months now, and I have been able to watch the dramatic improvement in her playing skills during that time. Thus, this story about the acoustics of the didgeridoo was quite interesting to me.

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 Tags: didgeridoo, acoustics

There is now a 50% chance of being infected by an internet worm in just 12 minutes of being online using an unprotected, unpatched Windows PC.

via Sophos

Why I blog this? I find the latest reseach results on malware infections to be sad and disturbing, even a little disgusting, but not at all surprising. It is going to get worse, a lot worse, before it begins to get any better.

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 Technorati Tags: virus, security, worms, windows, infection time

Olivier Toubia, a Ph.D. candidate at the Marketing Group (MIT) has an article (PDF) on Idea Generation, Creativity, and Incentives.

Idea generation is critical … However, there has been relatively little formal research on the underlying incentives with which to encourage participants to focus their energies on relevant and novel ideas.

This paper examines whether carefully tailored idea generation incentives can improve creative output.

Toubia used three types of incentives to trigger idea generation:

• A Flat condition where participants got $10 for showing up,
• An Own condition where participants got $3 for every idea they submitted, and
• An Impact condition where each participant got $2 for each time an idea they submitted built on one of their previous ideas.

See the sift everything experiment for a graph of the results.

Why I blog this? Because, as Jeremy says, “There is a lesson here for entrepreneurs regarding individual effort. If you can’t spend this kind of time [>20 hours], how can you hope to come up with deep, novel, thought-provoking ideas?”

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 Technorati Tags: Creativity, Ideas, Idea Generation, Incentives, Management Science

A new scale created by Michael Roukes and his colleagues at the California Institute of Technology can weigh items as small as a zeptogram (10^-21g), roughly the mass of a single protein molecule. The scale uses an extremely small vibrating blade made from silicon carbide. The blade is only 1000 nm long. By measuring the voltage of a wire attached to the blade, which vibrates in a magnetic field, researchers can determine the weight of whatever is placed on the blade.

The articles note that future devices that could even identify single molecules by weight, but to identify proteins by weight, the scales will have to become another 1000 times more precise, capable of weighing yoctograms (10^-24g), or individual hydrogen atoms. Just give it some time.

via BoingBoing via New Scientist
via Slashdot via BBC News

Laurence Fried and his colleagues at Lawrence Livermore National Laboratory in California decided to see if they could get water to go superionic. To do so, they recreated the conditions inside the giant planets of our Solar System. Such planets are extremely hot (more than 1,000 ºC) and have extremely high pressure (some 100,000 times the pressure on earth). The team used a device that smashed water between two diamonds. Then they heated the water with an infrared laser. The calculations and experiments appear to show water shifting to a superionic phase. It has been predicted for years that water in this weird state is structured such that the oxygen atoms are essentially frozen, but the hydrogen atoms can whiz around at high speed.

“By looking at [the frequency with which the water molecules vibrated] we are able to determine phase boundaries, but we don’t really know what is on the other side of the boundary.”

The researchers also studied computer models of the atoms’ behaviour, which suggested that the water had indeed entered a superionic phase, a strange state between solid and liquid. Tracking a group of some 60 simulated atoms took weeks, and required computing power equivalent to 1,000 laptops.

Why I blog this? It is cool science and I like to keep track of projects which require decent amounts of computing power. The amount of processing power in the world will continue expanding rapidly, and the price to compute will continue to drop. Thus, any problem which requires a lot of work to solve and is considered hard now could possibly be within reach a few years from now. My computer science background and entrepreneurial mindset scream “Opportunities abound!”

via news@nature.com

Recent research at the California Institute of Technology has confirmed that an area of the human brain, the ventrolateral prefrontal cortex (vPF), is involved in the planning stages of movement. The planning stages of movement happen during the instantaneous flicker of time when we contemplate moving a limb. This has implications for the development of brain-machine interfaces for the paralyzed as well as for able-bodied people who may seek to augment themselves with such technology. According the press release, the work currently appears in the online version of Nature Neuroscience. I do not subscribe to Nature so unfortunatly I can not access this paper.

“We were looking for the brain regions that may be contributing to planned movements. And what I was able to show is that a part of the brain called the ventrolateral prefrontal cortex is indeed involved in planning these movements.” Just by analyzing the brain activity from the implanted electrodes using software algorithms that he wrote, Rizzuto was able to tell with very high accuracy where the target was located while it was on the screen, and also what direction the patient was going to reach to when the target wasn’t even there.

Why I blog this? Practical consumer/amateur level brain-computer interfaces, with at least rudimentary functionality, are within reach. Obviously implanted electrodes are not practical for most people, but research is advancing in all directions. So, if we do get external BCI’s, even if they act simply as a new form of mouse, they will still be very hot technology to play with. I try to keep somewhat up to date on developments in this field.

via Caltech Press Release - Scientists Discover What You Are Thinking, March 16, 2005
via KurzweilAI.net

How much can we understand about human motion using only simple cues? Take a look for yourself using BioMotionLab1.6, a flash-based visual demonstration developed by an international team of researchers headed by Prof. Dr. Nikolaus Troje. Adjust four different sliders (male/female, heavy/light, nervous/relaxed, and happy/sad) to change the motion of the dots. It is amazing how much the human mind can ‘read’ from the motion, even though only minimal data is presented. I played around with it for a few minutes and found their simulation to be a fairly elegant examination of human movement using such a small number of points.

Dr. Troje holds a Canadian Research Chair in Vision and Behavioural Sciences. The Biomotion lab operates out of two locations: Queen’s University in Kingston, Ontario and Ruhr-University in Bochum, Germany.

From the Biomotion lab site:

We are working on several aspects of visual perception and cognition. Our major interest is focused on questions concerning the biology and psychology of social recognition. That is: conspecific recognition, gender recognition, individual recognition, recognition of an agent’s actions, intentions, and emotions and personality traits.

In the past, we had mainly worked on the psychophysics and modelling of human face recognition. More recently, our focus shifted towards perception of biological motion as a major source of social information.

The goal of our current work is to provide a solid basis for the description, analysis and synthesis of animate motion patterns. We want to achieve a comprehensive understanding of the information transmitted through biological motion, its perception and underlying neuronal mechanisms. In addition to human psychophysics, we are using the pigeon as a model for ethological and neurophysiological investigations in the context of courtship behaviour, social learning, and social fascilitation.

The procedure they used to create the display will be described in detail in a forthcoming paper submitted to the Journal of Vision. Troje, N. F. (submitted) Decomposing biological motion: A framework for the analysis and synthesis of human gait patterns.

Why I blog this? I referenced it in my Cybernetics and Society (STV205) class, but was unable to actually demonstrate the visualization because I did not have a computer available at the time. To anyone from class who was interested - Enjoy :)