Engineering around the spectrum crisis

Economic value increasingly takes the form of information, not of physical goods. Wealth therefore depends heavily on three things: our ability to store, compute, and communicate bits.

Of these three, by far the most limiting has come to be communication. There is no talk of a "memory crisis" or a "computation crisis": most of our computers use only a small portion of their available capabilities. Instead, we hear of a "spectrum crisis": the pressure on our ability to move information from one point to another. Cisco provides a summary of statistics. For instance, global mobile data traffic has more than doubled for the fourth year in a row.

Since 1949, our understanding of the limitations on our ability to move information has been governed by the Shannon law. Shannon's law tells us that "channel capacity", how much information we can move across a channel with Gaussian noise, is determined by two things: how much bandwidth we have available (the frequencies range we are allowed to use) and the signal-to-noise power ratio. 

The elegance of Shannon's law is mixed with a certain sense of tragedy. Bandwidth and power are both limited physical resources. They can be expanded only at considerable expense.

However, the mathematics Shannon used in his proof did not consider the full set of possible signals. By using a technique known as "Fourier analysis", he implicitly limited himself to signals based on periodic functions: that is, signals that regularly return to the same set of values.

It is also possible to base signals on non-periodic functions, which are far more flexible. Generalizing Shannon's law to non-periodic functions leads to an important insight, which is that channel capacity is not fully determined by bandwidth and the signal-to-noise ratio. A third parameter appears, which has to do with "slew rate": the ability of a communication system to handle rapid changes in amplitude.

The importance of this fact is that slew rate can be improved by better engineering. One does not have to buy it at spectrum auctions, or pay for it with larger and more expensive batteries. There is a relatively straight-forward means to design our way around the spectrum crisis.

For those with an interest in the mathematics, it is available here. 


 

The Homeric Method of Composing Epic Poetry

Literature is the art of lying in order to tell the truth. All fiction is constructed from lies; it becomes literature when the lies are arranged to reveal the truth.

It is a peculiarity of literature that its leading exponent (Homer) has been dead for nearly three thousand years. In reflecting on the possible reasons for this extended drought in literary production, the most obvious difference between Homer and later writers is that they were writers and Homer was not. Living near the end of an illiterate period in the Greek world, Homer's epic poems had to be composed and transmitted through memorization.

Given the relative quality of Homer's composition, this raises the suspicion that Homer's results were at least partially due to his technique itself. That memorization contributed significantly to smoothing Homer's poems into a highly polished form.

It is my belief that literature can be fully understood only by repeating the Homeric method of composing epic poetry entirely through memorization. I have written an essay, The Principles of Literature, describing this process from personal experience.

The Power of Positive Boredom

Engineering is the art of systematically making things boring. When a bridge falls down, that’s interesting; when it doesn’t fall down, that’s engineering.

How many people remember that on February 28, 2001, Seattle was hit by a magnitude 6.8 earthquake? The earth wobbled like Jell-O, people were rushed out of buildings, traffic lights swung, there was significant damage in places. But the city remained intact. No major buildings collapsed and at most one death could be attributed to the quake.

By contrast, a magnitude 6.1 earthquake that hit El Salvador the same month caused hundreds of deaths.

Although I was in downtown Seattle at the time, I had to look up what year it occurred, much less the day. The ability to forget a 6.8 earthquake was the gift of some very fine engineers. If the people of Seattle fully understood what happened on February 28th, 2001 (or rather, what did not happen) they would have erected a statue to the Unknown Civil Engineer. I am not noted as an earthquake survivor; I have no dead family or friends to mourn. The civil engineering community took a 6.8 earthquake and made it about as boring as it could possibly have been.

It is interesting to compare civil engineering with the software industry. According to Weinberg’s Second Law, “If builders built buildings the way programmers wrote programs, then the first woodpecker that came along would destroy civilization.” Certainly, a review of the Risks Digest, a moderated forum devoted to computer-related failures, makes for sober reading.

The Standish Group, which has studied tens of thousands of projects, puts the overall IT project success rate at 34% − a significant improvement over the last ten years, attributed to the increasing use of iterative software development methodologies.

The importance of iterative methodologies to successful software development is significant. Iterative methodologies involve designing and building software in a series of small stages, learning along the way from the previous stages.

While it is never described this way, iterative development amounts to systematized novice behavior. An expert sees the solution to a problem and goes straight to it; a novice takes a step, checks if he seems to have gone in the right direction, then takes another (tentative) step. The rise of the iterative development methodologies is essentially the tacit admission that the software industry does not quite know what it is doing.

To be fair, the challenge faced by software engineers is unprecedented. Every other engineering discipline is limited by the properties of materials; software is limited only by the properties of information (which is to say, complexity). Consequently, the problems faced by software engineers are more difficult than any the engineering community has ever been exposed to before.

Faced with an Everest of difficulty, success is possible only with care and humility. Iterative development moves in this direction, but a more general need is to systematically manage the feedback loops necessary to keep a project successful. Feedback loops reduce the number and magnitude of surprises; put more simply, feedback helps keep projects boring.

An important step forward is to explicitly combine an iterative methodology with systematic feedback from the end-user community. This step has been taken with the JackBe Application Methodology (JAM), which combines the iterative Rational Unified Process (RUP) with User-Centered Design (UCD).

Will feedback loop management by itself solve the software reliability problem? Certainly not. Another key problem is that software development tools in general use have not improved fundamentally since the 1970s, in terms preventing certain kinds of flaws from occurring.

We can only do what we can; but we must do no less than that. The software industry has a long way to go before it can say the equivalent of “You can take a 6.8 earthquake and forget about it. We’ve got you covered.” But that is the road we must be on.

Learning synesthesia

This blog is on learning synesthesia ("mixing of the senses"), as a follow-up to a Yahoo question.

http://uk.answers.yahoo.com/question/index;_ylt=AnL3uRGtu8P.zVtxaoo_G2BJBgx.?qid=20070502125359AAKeppm

I know synesthesia can be strengthened, by the means described below. I expect that it can also be built in people with no previous synesthetic experience, but so far as I know that is new territory.

For anyone interested in making the attempt, it's like falling asleep: you can't command it, you can only surrender to it. Start with some set of sensory stimuli that are simple, consistent, and frequently available, such as the alphabet, the numbers, or musical notes.

Pay attention to them, and notice any percepts (most likely colors) that might be associated with them. Initially, if you get anything at all, it will be weak and inconsistent. It's a bit like waiting for shy animals to come out to play. You can't rush it, you can't shape it, you can't even focus on it too directly. If you do, it will vanish like a dream. (Later, if you are successful, the percepts will become so strong and stable that you couldn't move them if you wanted to.)

The process is not quick or simple. It will be frustrating, and possibly disorienting. I would expect it to take at least several months, but I can't tell you for sure, because all I've found in the literature is a general presumption that it can't be done at all. But if those odds aren't too long for you, synesthesia can open up a new world.

Personally, having seen people who could not walk become able to walk, simply by altering their visual field, I am more inclined to believe things are possible than that they are not.

http://www.esnips.com/doc/e1d7c977-e25f-4494-8de0-16e00fb17e37/The-Treatment-of-Akinesia-Using-Virtual-Images

Here is a study showing that at least taste-smell synesthesia appears to be learnable.

http://www.nysaes.cornell.edu/fst/faculty/acree/fs616/pdf/Stevenson99.pdf

Finally, here is more on my own experience with synesthesia.

http://www.esnips.com/doc/31089b25-2f73-49d0-8ccc-07d9e938e7a7/Applied-Synesthesia-2005

Leonhard Euler

It is better to celebrate what was than to mourn what is not. On April 15, 2007, we celebrate the 300th birthday of Leonhard Euler, the finest mathematician of the 18th century.

To many, I’m sure, his name is unfamiliar. He won no battles, nor held high office: yet our world today is utterly dependent on his work. Those who serve quietly often serve best.

I chose to honor the occasion with a monograph on Euler’s formula, considering the implications of raising "i" in Euler's formula to fractional powers of two: coincidentally, the binary arithmetic of computers. You can think of it as Euler’s formula meets the digital age.

Prothero essays through 2006

Essays on various topics through 2006, with links to the ones on the web.


Prothero, J. (2006). JackBe Application Methodology (JAM). JackBe Corporation.
[A software development methodology that combines User-Centered Design (UCD) with a light-weight version of the iterative Rational Unified Process (RUP). UCD keeps the end-user’s needs in mind; iterative development provides the checkpoints to keep the project on target. Currently unreleased.]



http://www.esnips.com/doc/ea00d471-14fa-4461-ba73-6bae42765b9e/Ajax-Usability-Benefits-and-Best-Practices-2006
Prothero, J. (2006). Ajax Usability Benefits and Best Practices. JackBe Corporation.
[Rated #2 free Ajax document on the web by Intelligentedu:
http://www.intelligentedu.com/blogs/post/best_new_training_sites/3562/top-14-free-docs-on-ajax-web-design-and-strategy.]



Shaw, D. & Prothero, J. (2006). Unified Authentication for Warranty Chain Management. In Proceedings of Warranty Chain Management Conference.
[Application of content-centric security to efficiently maintaining authenticated warranty chain documentation.]



http://www.esnips.com/doc/31089b25-2f73-49d0-8ccc-07d9e938e7a7/Applied-Synesthesia-2005
Prothero, J. (2005). Applied Synesthesia: A Technique for Learning Languages.
[Synesthesia, the “mixing of the senses”, is usually seen as an innate and unlearnable characteristic of a small part of the population. This essay argues the opposite: that synesthesia is universal and learnable. Further, that synesthesia can be applied to reducing the memory burden of learning languages.]



Prothero, J. & Parker, D.E. (2003). A Unified Approach to Presence and Motion Sickness. In L.J. Hettinger and M.W. Haas (Eds.) Virtual & Adaptive Environments: Applications, Implications, and Human Performance Issues: Lawrence Erlbaum Publishers.
[Book chapter on the application of the Rest Frame Hypothesis to understanding the sense of “being in” a virtual environment and to mitigating motion sickness.]



http://www.patentstorm.us/patents/6497649.html
Parker, D.E., Duh, B-L., Furness, T.A., Prothero, J.D. and Seibel, E.J. (2002). Alleviating Motion, Simulator, and Virtual Environmental Sickness by Presenting Visual Scene Components Matched to Inner Ear Vestibular Sensations. US Patent #6,497,649.
[Patent on techniques for reducing simulator sickness, derived originally from the Rest Frame Hypothesis; see below.]



http://www.esnips.com/doc/72314eaf-5227-4c63-9307-605be467edad/Cyber-Defense-2001
Prothero, J. (2001). Cyber-Defense: A Strategic Approach to Defending our Critical Information Infrastructure..
[A strategic approach to securing the national IT infrastructure, based on the underlying causes for its weakness. Developed the idea of a “convenience overshoot” in the evolution of new technologies. ]



http://www.esnips.com/doc/b0d55b24-7d84-45c4-9644-5320ac3ecaf7/Customer-Confusion-Call-Kill-a-Website-2001
Prothero, J. (2001). Customer Confusion Can Kill a Web Site. Puget Sound Business Journal, April 20th issue. ps Tech: 28A.
[Why usability matters, from a business perspective.]



Prothero, J., Draper, M., Furness, T., Parker, D. and Wells, M. (1999). The Use of an Independent Visual Background to Reduce Simulator Side-Effects. Aviation, Space and Environmental Medicine, 70(3), 277-283.



http://www.esnips.com/doc/694da917-c923-4281-b68f-8a4217bc8989/The-Role-of-Rest-Frames-in-Vection,-Presence,--Motion-Sickness
Prothero, J. (1998). The Role of Rest Frames in Vection, Presence and Motion Sickness. Doctoral Dissertation, University of Washington.
[Borrowed the idea of a “rest frame” from physics and applied it to the psychology of spatial perception, particularly for virtual environments. Used to develop robust, psychophysical measures for presence and for mitigating simulator sickness. The “simulator sickness” application has been developed fairly thoroughly since, including the patent referenced above; the “presences measures” application is more open, if anyone is looking for a research topic in the human factors of virtual environments. (Incidentally, I have the dubious distinction of being one of the few people awarded a Ph.D. in mechanical engineering without ever taking a class in the subject, or knowing anything about it. The University of Washington didn’t know quite where to put me; a problem not unique to that institution.)]



Hoffman, H.G., Prothero, J., Wells, M. and Groen, J. (1998). Virtual Chess: Meaning Enhances Users' Sense of Presence in Virtual Environments.. International Journal of Human-Computer Interaction, 10(3), 251-263.
[The relationship between meaningfulness of information and the sense of presence in a virtual environment.]



Prothero, J.D. (1997). Rest Frames and "Class A" Presence Measures. In Proceedings of Human Factors and Ergonomics Society (HFES '97) [poster].



http://www.esnips.com/doc/a11444ef-b877-4330-b64e-97d3b69a6734/Do-Visual-Background-Manipulations-Reduce-Simulator-Sickness-1997
Prothero, J.D., Draper, M.H., Furness, T.A. III, Parker, D.E. and Wells, M.J. (1997). Do Visual Background Manipulations Reduce Simulator Sickness?. In Proceedings of International Workshop on Motion Sickness.



Draper, M., Prothero, J. and Viirre, E. (1997). Physiological Adaptations to Virtual Interfaces: Results of Initial Explorations (Technical Report R-97-26). Seattle: University of Washington, Human Interface Technology Laboratory.



http://www.esnips.com/doc/5c5637bb-d2db-437a-ac72-7430f9492094/The-Political-Science-of-the-Internet
Prothero, J. (1996). The Political Science of the Internet (Technical Report R-96-2). Seattle, Washington: University of Washington, Human Interface Technology Laboratory.
[Analyzed fundamental trends related to the Internet and projected their political and social implications. By the standards of futurology, it has aged pretty well.]



Prothero, JD (1996). Annotations from the 1996 Washington State Chess Championship. Northwest Chess.



Prothero, J (1996). Three Queen Knight Pawns. Northwest Chess.
[Taking the queen knight pawn with a queen is something that young chess players are warned against in the nursery. This is the story of one that could not be taken; one that should not have been taken; and one that had to be taken.]



Prothero, J (1996). An Adventure with the Frenkel French. Northwest Chess.
[1. e4; e6 2. d4; d5 3. e5; c5 4. b4. It looks bizarre, but has the effect of immediately dispelling Black’s central pressure. A variation I learned from Filipp Frenkel, who prefers to call it “Filipp Frenkel’s Fantastic French Phenomenon.”]



Prothero, J. and Hoffman, H. (1995). Widening the Field of View Increases the Sense of Presence in Immersive Virtual Environments (R-95-5). Seattle: University of Washington, Human Interface Technology Laboratory.



http://www.esnips.com/doc/be3bc6a0-89fb-405f-a231-f1ef0d227c16/Foreground-Background-Manipulations-Affect-Presence-1995
Prothero, J., Hoffman, H.G., Furness, T.A., Parker, D. and Wells, M. (1995). Foreground/Background Manipulations Affect Presence. In Proceedings of Human Factors and Ergonomics Society, pp. 1410-1414.



Prothero, J. , Parker, D., Furness, T. A., and Wells, M. (1995). Towards a Robust, Quantitative Measure of Presence. In Proceedings of Conference on Experimental Analysis and Measurement of Situational Awareness, pp. 359-366.



http://www.esnips.com/doc/ccb2622c-e249-4ee2-9568-75dea5eaee53/Interface-Goodness-Measures-1994
Prothero, J. (1994). A Survey of Interface Goodness Measures (R-94-1). Seattle: University of Washington, Human Interface Technology Laboratory.



Weghorst, S., Prothero, J., Furness, T.A. III, Anson, D. and Riess, T. (1994). Virtual Images in the Treatment of Parkinson's Disease Akinesia. In Proceedings of Medicine Meets Virtual Reality II, pp. 242-243.



http://www.esnips.com/doc/e1d7c977-e25f-4494-8de0-16e00fb17e37/The-Treatment-of-Akinesia-Using-Virtual-Images
Prothero, J. (1993). The Treatment of Akinesia Using Virtual Images. Master's Thesis, University of Washington, College of Engineering.
[This was the first formal research showing that Parkinson’s disease akinesia (“freezing”) can be mitigated by providing a virtual image for the patient to react to.]



Prothero, J.D., Prothero, J.W. (1985). TOPPER, a Software Package in ForTran For Scaling Studies. International Journal of Biomedical Computing 17(3-4):185-91.