Nuclear Rapture- 23:58

It’s two minutes to midnight. For the last 2.5 million years or so, we’ve lurched along a hairline equipotential in the vast, catastrophic universe. Rapture is so near you might even be able to peer over the ridge. This is where all that becoming has brought us. Finally, we will know instant solidarity. Annihilation unites us all.

Continue reading

Mechanical Jerk

"You know, a lot of great music was written during the Nixon regime. We're on the verge of a social movement not seen since then, so there's an urgent need for any music or noise that helps channel our collective energy and anger." - T.G.

"You got it." - me

Continue reading

Warm Jets

Warm Jets is a new vst plugin I've made. It provides three, independently bypassable, high-quality effect units in a network with feedback, which allows for a diverse range of transformations ranging from subtle psychedelia to bleary washes. Warm Jets can easily self oscillate, making it a powerful synthesis tool in its own right.
Continue reading

Empirically Derived Distance Measures for the Z-Plane

In this post, I test the effects of infinitesimal, orthogonal movements of a single complex pole on mean squared error in residual estimation. The goal is to find and validate a distance metric that relates residual estimation to estimation of eigenfrequencies. My hypothesis, derived from informal inspection of large related datasets, is that such a distance metric will correspond to that of the Poincare disc model.
Continue reading

Tikhonov Regularization and Residual Estimation, part II

The previous 2 posts have demonstrated the effects of Tikhonov Regularization on a polynomial regression algorithm. This post continues to explore Tikhonov Regularization's effect on out of sample residual and eigenvalue estimation. In order to provide a better analysis of the out-of-sample error, animated scatterplots were created of the eigenvalue estimates for a number of iterations of the learning algorithm, as the Tikhonov Regularization parameter, \alpha swept from 0 to 10^{-5} in steps of 10^{-6}. This range for \alpha was chosen after numerous trials suggested it could be a possible optimal range. In addition to trends in eigenvalue estimation, this experiment also plotted those in residual estimate error.

Continue reading

Tikhonov Regularization and Residual Estimation

In this post, I explore the effects of Tikhonov regularization on out-of-sample residual estimation using polynomial regression, as part of a continued effort to validate a machine learning algorithm for modal analysis. The algorithm estimates spatially distributed modes in a signal, and uses this information to estimate the residual, or forcing function, of a physical model. Today's experiments explore the frequency-domain effects of the regularization parameter \alpha on residual estimates.
Continue reading

A Z-Plane View of Regularization

A z-plane analysis of Tikhonov regularization in polynomial regression algorithms shows that an increased weight decay factor \alpha generally corresponds to eigenvalues of reduced radii. Such a strategy offers increased out-of-sample error in regression models, effectively an insurance policy against overfit. A number of experiments demonstrate the filterbank representation of this technique for a variety of values for \alpha.

Continue reading

Forcing Function Estimates as a Function of Modal Damping

In a previous article, a method was described for the estimation of the residuals measured in a resonant system, given a small amount of memory of previous values in the timeseries. The previously supplied formulas are thought to be applicable in single as well as multiple timeseries. The accuracy of estimation is thought to be affected by several parameters in the analysis, and the dynamic behavior of the measurements themselves. In this experiment, we attempt to correlate estimation accuracy with modal damping. My hypothesis was that, on average, the estimation accuracy would be negatively affected by increased damping. This reasoning came from previous work wherein the accuracy of eigenvalue estimation was observed to be much better when those eigenvalues had larger radii, and therefore less damping.

Continue reading

Forcing Function Estimation in Modal Analysis

In an earlier post, I described a technique for modal analysis which can estimate damped modes of vibration in an object, as measured at a variable number of points on its surface. I have applied this technique to field data from an array of laser microphones, measuring waves on the surface of the water. Now I will develop the mathematics and practical considerations behind estimating the forcing function in such recordings.

Continue reading

Regarding the Last 3 Posts

The last 3 posts were chapters from my PhD qualifying exam at UCSD, which I wrote over the course of 12 days (to the hour!) from Dec 12th to Dec 24th, 2013. It's a document I had to write so that I could start working on my dissertation. The stuff I wrote may make it into a publication or two, but in the meantime I thought it'd be nice to share it on the internet. In case my server doesn't display the equations right, you can grab the print version here. I recommend reading it in bed, as a cure for insomnia. 😉 Enjoy!

Wave Propagation and States of Vibration

"If you were trying to measure how a solid object vibrates, the question might be broken down into two sub-questions: how does the object vibrate in general, and what is its specific vibrational state at a given moment in time. What models have you found that might be useful for describing the vibratory behavior in general, and what are the prospects for picking up specific vibrational state information? Is it possible to predict under what conditions it will be possible to make these measurements on real objects, and/or how the number of sensors available might affect the quality of measurements that are possible?"

-Miller Puckette

Continue reading

Remote and Coupled Vibration Measurement Methods

"Imaging small vibrations have been of interest since Chladni first placed sand on a vibrating plate to make modal patterns visible. Discuss methods that have since been developed to remote sense and optically image sub-micrometer vibrations (e.g. laser Doppler vibrometry, holographic interferometry, electronic speckle pattern interferometry, etc.) including your own method currently being developed. Discuss the pros and cons of each method, and how your own method capitalizes on the strengths---or attempts to overcome any limitations---of its predecessors in the context of your particular application requirement(s)."

-Tamara Smyth

Continue reading

Measurement and Mysticism in Early Alvin Lucier

"A thread running through a number of Alvin Lucier's early works seems to be an urge to equate musical performance with an act of scientific observation, or measurement. With sound, room acoustics, and various corollaries of sound as the declared objects of this observation, Lucier seems to put musicians and listeners in a shared encounter with ``nature'' and ``the natural world'' that combines elements of science, mysticism and universalism. What are the sources of these notions of ``nature'' and art-making, and what is the context in post-World War II America that gives rise to this interest in measuring the behavior of sound as an aesthetic? What conclusions can be drawn from the language, methodologies and idea-world that Lucier makes use of?"

-Charles Curtis

Continue reading

Laser Triangulation Microphones

I've completed two laser microphone components that use the triangulation technique in conjunction with a high-bandwidth photodiode. These can be used to pick up vibrations remotely on any reasonably reflective surface. A production run of 12 is almost complete. Click through for pictures!
Continue reading

Photodiode Amplifier Design for Optical Vibrometry

The central goal of this project is to design a geometric optical vibrometer array. This device will be capable of measuring transverse waves across a wide band of frequencies, without mass-loading the object. The design parameters to be minimized include cost, power consumption, and noise floor. The parameters to be maximized include signal gain, bandwidth, and versatility. The device is intended to be suitable for both researchers and artists interested in mechanical vibrations.

Continue reading

Odum~

for some time now, i've been interested in the work of howard t. odum, zoologist and pioneer in the field of systems ecology. h. t. odum's goal was to derive a language for the transformation of energy into different forms, which could represent such transformations as edges in a network.his notational system, called "energy circuit language", borrows from other systems theory notations such as forrester diagrams or electrical schematics, but diverges from such systems in an attempt to describe systems in even more general terms. h. t. odum spent years honing this language by attempting to model the data he and his brother eugene odum, a zoologist and ecologist as well, collected from various ecosystems. the two brothers are ostensibly responsible for the modern conception of the term 'ecosystem' itself.

Continue reading

ADC Pre-Amp Stages

in a previous post, i mentioned that the adc's on the cortex m4f microprocessor were unipolar, and i included a link to a simple op-amp circuit that could provide the appropriate voltage shift and scale operation. yesterday, i went from designing a layout to fabricating 9 boards in 24 hours. actually, i made 11 boards, but lost two in the process, because of issues relating to old pcb stock. in the future, i might design two layouts for each board, with the alternate layout applying wider tolerances, to account for older pcb stock. i used a positive photofabrication method for applying resist to the boards, which in my experience provides the sharpest lines. i used eagle cad to design the layouts, and gimp to beautify them. as per usual, the values for the components are etched right into the copper, so no silkscreen layer was necessary.

Continue reading

A Linux-Based Open Source Toolchain for the STM32F4

ST Microelectronics has released the STM32F4 "Discovery" evaluation board for the M4f Cortex ARM processor chip. In addition to the M4f ARM microprocessor, itself a pretty awesome tool boasting 32bit floating point precision and a vast array of assignable I/O capabilities, the STM32F4 is loaded with tons of sensors, USB hosting capabilities, and even a fully accessible ST-Link V2 programmer, which allows the user to program other M4f microprocessors. Check out this great demo / explanation here.

Continue reading

Hrokk On

i have been working on a new instrument design, conceived of during a few conversations with berglind tomasdottir. it's called a "hrokkur," which is a play on words in icelandic, a blend between the words "rokkur," meaning spinning-wheel, and "hrokk," meaning rock ('n roll). the instrument is very similar to a hurdy-gurdy, which is a medieval stringed instrument that makes sound with a circular bow. i designed the instrument using readily-available, frequently recycled materials-- mainly a guitar and a bike.

Continue reading

This Is Not Art: Australia, 2011

this fall, i was privileged with the opportunity to participate in two arts festivals in newcastle, australia. these festivals were "electrofringe," whose focus was on the practice of electronic arts, and "critical animals," whose focus was the critical theory underlying creative endeavors. both of these festivals are components to a larger meta-festival called "this is not art." i was invited to engage in a variety of artistic and pedagogical events, some of which were newly realized just for the festivals (viz. songbirds).

Continue reading

Bugs!

alright, so nobody's perfect. when i drew up my board layouts in the last post, i made a few mistakes which prevented the initially stuffed boards from working. most of these mistakes are super embarrassing because they're pretty obvious. i will attempt to write these out linguistically, and eventually i will get around to actually drawing up a new board layout that implements these changes. refer to the schematic for the part numbers and their place in the topology.

Continue reading

DIY Etching: Songbird b

i've been working on a networked sound installation inhabited by simple automatons called "songbirds." i have previously done another incarnation of this idea, so i'm working on version "b" now. the idea for this particular version actually came from cicaidas, not birds, but the name has stuck for better or worse. maybe the "b" stands for "bug?"

Continue reading

Etape

Creosota is an electro-folk project featuring Adam Tinkle on guitar and vocals, and Joe Mariglio on laptop & contact mics. Their live sound often incorporates complex rhythms, bluesy folk idioms, field recordings, and massive vocal textures. Skittering glitch-hop beats co-mingle with fingerpicked guitar and the sounds of distant (sometimes not-so-distant) trains.

Continue reading

DIY Mbira

The Universal Language Orchestra is continuing into this fall with a new grant from UCIRA! As part of our proposal, we have been coming up with musical ideas and instruments to stimulate our young (8 - 12 year old) students' imaginations. This summer, my role has evolved into research and development of these instruments, with the intention of breaking down the expectations and implicit hierarchy concomitant with traditional instruments.

To this end, Adam Tinkle and I have come out with designs for a very inexpensive mbira, or "thumb piano", which can be easily amplified and otherwise extended to include all sorts of other sound-making possibilities. While the prototype demonstrates something very similar to a traditional (albeit non-Western) instrument, we see this as a platform on which to extend into further sonic zaniness and fun.

Continue reading

Sonic Shredder v0.2

This summer, I had the privilege of working on a software project with a client who trusted my aesthetics implicitly. He understood what I was about, and asked me to make him a software instrument in SuperCollider that could eat other software instruments for breakfast. In return, I gave him the Sonic Shredder.

Continue reading