hakank.blogg

april 11, 2008

Mailen strular förhoppningsvis inte längre

Till dem det berör:

Mail till mitt vanliga mailkonto ( hakank@bonetmail.com ) funkar inte för tillfället. Möjligen beror detta på underhållsarbete hos mailprovajdern. Lika möjligen kan detta mailavbrott vara över helgen. Jag vet inte eftersom det inte kommit någon information och sajten deras är stängd för underhåll.

Vill ni nå mig så använd hakank@gmail.com i stället.

Lördag klockan 17:37 började mailen funka igen.

Uppdatering Lördag 19:15 Nähä. Det slutade funka igen. Så ovanstående gäller fortfarande. (Ledsen alla ni med RSS-bevakare för denna fortlöpande uppdatering.)

Uppdatering Söndag 19:28 Nu beslutar jag att mailen verkar vara OK.

(Eftersom jag nu tydligen har börjat blogga så smått igen - två bloggningar i samma månad ! - kanske det berättigar till att inbjuda till en Malmö-bloggareträff igen? Eller krävs det mer bloggaktivitet för sådant? Någon gång i slutet av april/början av maj? På King Long blir det i så fall. En söndag eller torsdag?)

Posted by hakank at 10:36 EM Posted to Diverse vetenskap | Comments (4)

oktober 09, 2007

Lite länkar till videoföreläsningar 20071009

En dump av videoföreläsningar sparade i Bloglines. Allt har inte setts men verkar skoj av en eller annan orsak.

* Decision Science News R video tutorial number 2.

* UCTV Game Theory 2007. Kurs i spelteori. Se även kursens outline.

* En samlig av vetenskapliga experiment av mer vardagligt slag finns på Robert Krampf's Science Videos.

* KDD 2007 The 13th International Conference on Knowledge Discovery and Data Mining (en massa föreläsningar). För den delen finns det flera andra föreläsningar på videolecures.net såsom AAAI-07 AI Video Competition och PASCAL Bootcamp in Machine Learning.

* David Henderson, Charles Hooper Making Great Decisions

The phrase "work smarter, not harder" has been repeatedly ridiculed in Dilbert and ... all » elsewhere, not because it is a poor idea, but because it is thrown like a brick lifesaver to drowning employees. It's like telling someone to be happier, healthier, and richer. What people need is a plan for doing so.

In "Making Great Decisions" the authors show readers how to achieve their objectives. They offer a better way to look at problems so that solutions are easier to find.

Speaker: David R. Henderson, Ph.D. David R. Henderson is an economics professor at the Naval Postgraduate School in Monterey and a research fellow with the Hoover Institution at Stanford. He was a senior economist with President Reagan's Council of Economic Advisers.

Speaker: Charles L. Hooper Charles L. Hooper is President and co-founder of Objective Insights, Inc., a consulting firm dedicated to providing health care companies with marketing and financial analysis to help them make informed decisions about their business opportunities.

* Ross Anderson Searching for Evil

Computer security has recently imported a lot of ideas from economics, psychology and ... all » sociology, leading to fresh insights and new tools. I will describe one thread of research that draws together techniques from fields as diverse as signals intelligence and sociology to search for artificial communities.

Evildoers online divide roughly into two categories - those who don't want their websites to be found, such as phishermen, and those who do. The latter category runs from fake escrow sites through dodgy stores to postmodern Ponzi schemes. A few of them buy ads, but many set up fake communities in the hope of having victims driven to their sites for free. How can these reputation thieves be detected?

Some of our work in security economics and social networking may give an insight into the practical effects of network topology. These tie up in various ways with traffic analysis, long used by the signals intelligence agencies which trawl the airwaves and networks looking for interesting targets. I'll describe a number of dubious business enterprises we've unearthed. Recent advances in algorithms, such as Newman's modularity matrix, have increased the robustness of covert community detection. But much scope remains for wrongdoers to hide themselves better as they become topologically aware; we can expect attack and defence to go through several rounds of coevolution. I'll therefore end up by talking about some strategic issues, such as the extent to which search engines and other service providers could, or should, share information in the interests of wickedness detection.

Speaker: Ross Anderson Ross Anderson is one of the top security researchers in the world.

* Philip Chan Learning Rules for Anomaly Detection

Anomaly detection has the potential to detect novel attacks, however, keeping the false ... all » alarm rate low is a challenging task. We discuss the LERAD algorithm that can learn concise and accurate rules for anomaly detection and demonstrate its effectiveness in network and host datasets. We will also discuss our recent work (KDD 07) on weighting versus pruning during the rule validation.

If there is more time, I can also talk about:

As mobile devices become more pervasive, we study the problem of spatial-temporal anomaly detection for identifying potential abuse. We discuss the STAD algorithm and show its performance on a cell phone dataset.

* Geoffrey West Scaling Laws In Biology And Other Complex Systems

Life is very likely the most complex phenomenon in the Universe manifesting an ... all » extraordinary diversity of form and function over an enormous range. Yet, many of its most fundamental and complex attributes scale with size in a surprisingly simple fashion. For example, metabolic rate (the power required to sustain the system) scales as approximately the 3/4-power of mass over 27 orders of magnitude from molecular levels up to the largest multicellular organisms. Similarly, time-scales, such as lifespans and growth-rates, increase with exponents which are typically simple powers of 1/4. It will be shown how these universal quarter-power scaling laws follow from fundamental generic principles embedded in the dynamics and geometry of underlying networks, leading to a general quantitative theory that captures essential features of many diverse biological systems. Examples will include animal and plant vascular systems, growth, cancer, aging and mortality, sleep, DNA nucleotide substitution rates. These ideas will be extended to discuss social organisations such as cities and firms: to what extent, if at all, can we think of these as very large organisms and therefore as an extension of biology? Analogues to metabolic rate and behavioral times in cities scale counter to their behaviour in biology. Driven by innovation and the creation of wealth this has dramatic implications for their growth, development, sustainability and pace of life which, left unchecked, potentially sow the seeds for their collapse.

Geoffrey West is a theoretical physicist whose primary interests have been in fundamental questions in physics, especially those concerning the elementary particles, their interactions and cosmological implications. Prior to joining the Santa Fe Institute as a Distinguished Professor in 2003, he was the leader, and founder, of the high energy physics group at Los Alamos National Laboratory, where he is one of only approximately ten Senior Fellows. «

* Lynn Robertson Is That My Brother? Perceptual and Neurobiological Factors in Face Blindness

Face blindness (technically known as prosopagnosia) is a condition in which people with otherwise normal vision cannot discriminate one ... all » face from another. They may not be able to pick out their own husband or children in a crowded room or even themselves in a mirror. One woman reported she once had to crinkle her face in a crowded rest room to discriminate herself from others in the mirror. This problem can occur through injury to particular areas within the brain (either through head trauma, stoke or surgery), but it can also occur developmentally. In the latter case, the brain appears completely normal, yet developmental prosopagnosics (DP) have never learned to accurately discriminate faces.

There is a large scientific body of work on face perception published in the psychological, social and neurobiological literature, and I will highlight some of the more important findings. I will then discuss work from my own laboratory on perceptual processing of faces; emphasizing training methods we have developed to help individuals with DP identify faces, sometimes for the first time in their lives. This discussion will be complemented by inclusion of documented neurobiological and cognitive changes that accompany the emergence of face recognition abilities.

* Erin McKean Wordmaking: What it take to succeed in hacking English and invent a new word

Earn the basics of word formation in English, get "raw materials" for new words, and invent ... all » your own word (and have it critiqued) before you let it loose into the English language. The maker of the "best new word" (as voted on by the participants) will win a new dictionary.

Posted by hakank at 06:53 EM Posted to Diverse vetenskap | Video podcasts | Comments (2)

februari 22, 2007

Länkar 20070222

Notationssystem
Pasta and vinegar: How to write gestures and movements, om olika notionssystem för gester och rörelser.

nicolas novas förklaringar varför han bloggar om en speciell sak, dvs "Why do I blog this?", är eftersträvansvärda. Således: Det är fascinerande med notiationssystem för mundäna saker.

Reguljära uttryck
A Neighborhood of Infinity: Modular arithmetic with regular expressions sätter tänderna i följande problem:

Problem: Find a regular expression, compatible with GNU grep, that recognises strings of 1's and 0's that form the binary expansion of multiples of 7.

Ambigram
3-D Ambigram Generator
Se även About (om sajten, där "ambigram" förklaras.)

Och varför inte kolla in Scott Kim och dennes Inversions när vi ändå håller på.
Det verkar - apropå det - som om det finns en generation (eller två) utvecklare ("geekar") som inte läst (eller ens känner till) den fantastiska boken Gödel, Escher, Bach. Den gjorde bl.a. självreferenser till ett populärt salongsämne, men handlar även om allt annat. Mer om boken finns att läsa här.

Apropå regexpar: Lambda the Ultimate Regular Expression Matching Can Be Simple And Fast

Data mining och terrorism
Jeff Jonas: Effective Counter-Terrorism and the Limited Role of Predictive Data Mining

The key point of our paper is that the form of data mining which uses historical incident data to determine a pattern … then using this pattern to predict a future event is not helpful in the terrorism context because there isn’t enough historical data to derive a meaningful and statistically reliable pattern. Thus, we settled on the term "predictive data mining" to differentiate what we were characterizing as ineffective from many other effective uses.

Detta angående ett paper som Jonas och Jim Harper skrivit: Effective Counterterrorism and the Limited Role of Predictive Data Mining (PDF).

Via bl.a. Data Mining Research, som kommenterar med följande:

I think that we need to distinguish between the usefulness of data mining for terrorism (i.e. can we extract meaningful knowledge from data) and the possibility to use it in everyday life (i.e. is it effective, too expensive, not ethical?). In the paper, authors only argue that data mining for terrorism waste time and money. Although they have good arguments, they are not directly related to technical aspects of data mining.

Cf TheStar Thinking like the 'bad guys' the aim of university project (länk från ovan).

Change blindness
Wikipedia: Change blindness:

Change blindness is a phenomenon in visual perception where apparently large changes within a visual scene are undetected by the viewer. Typically for change blindness to occur, the change in the scene has to coincide with some visual disruption such as an eye movement or a brief obscuration of the observed scene or image.

Mixing Memory Coolest... Experiment... Ever berättar om ett berömt experiment kring detta.

Se även
Change Detection Database
The Need for Attention to See Change med andra exempel.

Posted by hakank at 08:48 EM Posted to Diverse vetenskap | Comments (1)

februari 16, 2007

Ansikten: länkar 20070216

Det blev visst mest om ansikten idag.

New York Times: Faces, Faces Everywhere

Why do we see faces everywhere we look: in the Moon, in Rorschach inkblots, in the interference patterns on the surface of oil spills? Why are some Lay’s chips the spitting image of Fidel Castro, and why was a cinnamon bun with a striking likeness to Mother Teresa kept for years under glass in a coffee shop in Nashville, where it was nicknamed the Nun Bun?

...

Dr. Sinha of M.I.T. says that whether the hair-trigger response to faces is innate or learned, it represents a critical evolutionary adaptation, one that dwarfs side effects like seeing Beelzebub in a crumpled tissue.

Pawan Sinha

Mind Hacks: Faces, faces everywhere

The Face Clouds

Cognitive Daily: Why we see faces when they're not really there (with poll!)

Wikipedia: Apophenia: Apophenia is the experience of seeing patterns or connections in random or meaningless data.
Wikipedia: Pareidolia: Pareidolia [...] describes a psychological phenomenon involving a vague and random stimulus (often an image or sound) being mistakenly perceived as recognizable.

Mind Hacks: Beauty and the average girl, Average girls are hot

Seed Magazine: Beauty is in the processing time of the beholder: Prototypical faces are pleasing because they're easy for the brain to process.
Piotr Winkielman, Prototypes are attractive because they are easy on the mind (PDF)

Face Research

Figurer i moln

Här passar det utmärkt att länka till det trevliga Malmöföretaget Polar Rosesom specialicerat sig på ansiktsigenkänning.

The web is increasingly becoming visually oriented, progressing from text to photos and other rich media. Close to 10 million new photos are uploaded on a daily basis, a number which is doubling every eight to ten months.

Photos tell many stories, but unlike text, the context of a photo is hard to search for unless explicitly "translated" by a human being. The photo web of today is like the text web before Altavista, Inktomi, and Google.

Polar Rose makes photos searchable by analyzing their content and recognizing the people in them.

Polar Rose blog.

Posted by hakank at 06:25 EM Posted to Diverse vetenskap | Machine learning/data mining | Comments (2)

februari 04, 2007

Smånotiser 20070204

• Daria Sorokina, Johannes Gehrke, Simeon Warner, Paul Ginsparg: Plagiarism Detection in arXiv (publicerad på arXiv)

  We describe a large-scale application of methods for finding plagiarism in research document collections. The methods are applied to a collection of 284,834 documents collected by arXiv.org over a 14 year period, covering a few different research disciplines. The methodology efficiently detects a variety of problematic author behaviors, and heuristics are developed to reduce the number of false positives. The methods are also efficient enough to implement as a real-time submission screen for a collection many times larger.

  Slutsatsen:

  We identified over 500 cases of likely plagiarism from other authors, and additionally over 1000 cases of likely mild plagiarism. These constitute roughly 0.5% of the corpus, and an even smaller percentage of authors, since many come from repeat offenders. Some of the problems are quite serious, and many of the articles are published in conventional venues. None of the plagiarizers, the victims, nor their publishers have yet been notified, hence they remain anonymized here. We can, however, dispel some uncertainty by pointing out that while prominent (highly cited) authors are frequently victimized, they do not appear to reuse text from others.
  

  
  Man kommer för övrigt fram till att följande 7-gram är de vanligaste fraserna (kanske inte helt förvånande)
  
this work was supported in part by
can be expressed in terms of the
work was supported in part by the
first term on the right hand side
it is easy to see that is
operated by the association of universities for
department of physics and astronomy university of
the paper is organized as follows in
there is one to one correspondence between
term on the right hand side of


• Den oförliknelige matematikern Doron Zeilberger rasar vidare kring kvaliteten i granskningen (peer-review) i matematiska tidskrifter i Opinion 77: Take This Math Journal and Shove It, Ain't Submitting there No More:
  

  So you submit your latest paper, that you worked so hard on, and are so excited about, and (usually) justly proud of, and six months later (if you are lucky, sometimes it takes a year or longer), you get the referee's (or referees') report(s). With probability 5 percent, it would be a raving acceptance, but more likely, even if it gets accepted, the report would be lukewarm, obnoxious, and often written in sarcastic or patronizing style, that the referee can afford because of his or her anonymity. That report also sometimes contains comments that truly prove that the referee misunderstood the mathematics and the main point.

  
  

• Två artiklar om hänthet från Cognitive Daily:
  
  
  
  • Left-handers have faster connections between brain hemispheres
    
  • Optimists: We become ambidextrous as we age; Pessimists: We lose skill in dominant hand as we age
    

  Cf. Vänsterhänthet, Vänsterhäntas dag.

• Chih W. Khoh, Peter Kovesi: Animating Impossible Objects (från augusti 1999):

  Three-dimensional models of impossible objects can only be viewed from one angle - otherwise they no longer look impossible. But is it possible to create an interactive impossible object, that is, an impossible object that can be viewed from any angle? This paper explores the creation of such objects on the computer.
  

• Clive Thompson i Collision Detection: Equation determines Jan. 23 is "worst day of the year". Och jag kan inte annat än att hålla med i hans (här fetmarkerade) slutkläm
  Obviously, the variables in the equation are personalized, so Arnall's proclamation of Jan. 23 as the singlemost depressing day might not hold true for you. More obviously yet, this doesn't seem to be even vaguely scientific since Arnall doesn't offer any data to back up his equation, his association with Cardiff University seems to be ungoogleable, and the whole thing smells like a PR endeavour.

  I still don't care. I am such a sucker for pseudo-precise equations that purport to clarify everyday life.
  

• Från samma källa och troligen med samma tunga i samma kind: A Nobel Prize adds two years to your life

• En snillrik device för de som ständigt skjuter upp saker (prokrastinatörer) såsom att gå upp på morgonen: The Procastinator’s Clock .

Posted by hakank at 11:06 FM Posted to Diverse vetenskap

januari 24, 2007

Gustav Holmberg pratar om meteorologi i P1

Gustav Holmberg, ur-bloggare, medkotterist och vetenskapshistoriker pratar om meteorologi i dagens (repriserad från 21 januari 2007) UR Bildningsbyrån:

I Bildningsbyrån i P1 får vi även höra om meteorologins historia. Idéhistorikern Gustav Homberg berättar om hur vi fick väderobservationer och också om samspelet mellan meteorologin och oss ”vanliga” väderobeservatörer. Vi pratar om olika sätt att förutsäga väder.

Hoppas att programmet blir publikt tillgängligt snart.

Uppdatering Tack till Johan för hans språkliga korrektion av "meterologi" till det korrekta "meteorologi". Den vanliga [24700 på google] felstavningen beror säkert på att vi har ett meter-system och inte meteor-system... Och ett - något senare - tack till Hr. Klippspringer som påpekade rättstavningen av det berörda ordet i första uppdateringsmeningen när det skulle vara felstavat. Suck, det är inte lätt det här. Hr Klippspringers Sesemania-referens blir något mer förståelig om man läser detta.

Hmm, det här var ju ett bra sätt att få kommentarer. Men då ska det vara intresantta (sic!) felstavingar (sic!),:-)

Posted by hakank at 09:25 EM Posted to Diverse vetenskap | Comments (7)

januari 17, 2007

Länkar 20070117

Förhalningens formel
We're sorry this is late; we really meant to post it sooner - Research into procrastination shows surprising findings
Slashdot: Formula For Procrastination Found
collision detection: The formula of procrastination

Amusia: "tonblindhet"
Mind Hacks: Without music
BBC: Amusia

Makt och personlighet
collision detection: Study: Powerful people can't draw a reversed "E" on their foreheads
Paper: Adam D. Galinsky, Joe C. Magee, M. Ena Inesi, Deborah H Gruenfeld
Power and Perspectives Not Taken (Microsoft Word)

"Ölögon" (beer goggles)
BBC: 'Beer goggles' effect explained (via Improbable Research)

Rankningssystem i schack
(jag spelar inte schack speciellt mycket men är nyfiken på olika typer av rankningssystem):
Mark Glickman Research Page
A Conversation with Mark Glickman
(via Statistical Modeling, Causal Inference, and Social Science)
Cf. t.ex. Wikipedia ELO Rating System

Klimatforskning
Physics Today: The physics of climate modeling (via Real Climate)

Bayesian Poisoning
Does Bayesian poisoning exist? (via Wikipedia Bayesian Poisoning via Statistical Modeling, Causal Inference, and Social Science Statistical models and spam)

Posted by hakank at 09:32 EM Posted to Diverse vetenskap

november 08, 2006

Dagslänkar 2006-11-08

Cirka en veckas länkar...

Vetenskap & Allmänhet: Astrologi vetenskap enligt var fjärde svensk. Undersökningen Allmänhetens syn på Vetenskap 2006 (PDF).

En ny JASSS (Journal of Artifical Societies and Social Simulation) har kommit. Innehåller t.ex.
Sujai Kumar, Sugata Mitra: Self-Organizing Traffic at a Malfunctioning Intersection:
Traffic signals and traffic flow models have been studied extensively in the past and have provided valuable insights on the design of signalling systems, congestion control, and punitive policies. This paper takes a slightly different tack and describes what happens at an intersection where the traffic signals are malfunctioning and stuck in some configuration. By modelling individual vehicles as agents, we were able to replicate the surprisingly organized traffic flow that we observed at a real malfunctioning intersection in urban India. Counter-intuitively, the very lawlessness that normally causes jams was causing traffic to flow smoothly at this intersection. We situate this research in the context of other research on emergent complex phenomena in traffic, and suggest further lines of research that could benefit from the analysis and modelling of rule-breaking behaviour.
Det finns även en simulering i NetLogo (kräver Java).

The Geomblog: The Snowblowing (or leaf raking) problem

YouTube: Mad Scientist Competition in Helsinki (naturligtvis via Improbable Research)

Scientific American Mind: om Paul Ekman och microexpressions A Look Tells All A person's face will always reveal his true feelings--if, like Paul Ekman, you are quick enough to recognize microexpressions

New Scientist: Solved: the perfect way to cut a cake
The art of cake-cutting requires great care and skill to ensure no party is left feeling cheated or envious. Now, however, parents and party hosts can approach the task with a little more confidence – mathematicians claim to have found the perfect way to cut a cake and keep everyone happy.
Se även:
Steven Brams, Michael A. Jones, Christian Klamler: Better Wayts to Cut a Cake (PDF)
Steven Brams
Steven Brams Fair Division - From Cake-Cutting to Dispute Resolution (1996, ISBN: 0521556449 )
Perfekt kakdelning

John Allen Paulos i ABC News: Who's Counting: Which 'Experts' Make Better Political Predictions?

Veckans spel är Bubbles. För att citera mig själv så är det en 8 på Tetris-skalan. Via Spinster and Spin(n)ster.

Den skönlitterära bok som just nu läses är Michael Crichton State of Fear (2004, ISBN: 0061015733) som här förmedlar sin version av miljöförstöring och eko-terrorism. Liksom hans Prey är det en blandning av fakta och fiction som jag som PopSci-junkie har väldigt svårt att stå emot (även om det ibland kan vara svårt att veta vad som är fakta och vad som är fiktion). Litteraturreferenslistan är stor även denna gång.
RealClimate diskuterar boken här.
NOM var inte speciellt road.

Posted by hakank at 06:52 EM Posted to Diverse vetenskap

november 02, 2006

Dagslänkar 2006-11-02

Lennar Sjöberg: Are all crowds equally wise? A comparison of political election forecasts by experts and the public (PDF):
In this study, 4 groups of people made prognostic judgments of the outcome of the Swedish Parliamentary election in the fall of 2006, about one week before the election. The groups consisted of members of the public (N=123), political scientists (N=53), journalists writing about domestic politics in Swedish daily newspapers (N=32), and journalists who were editing sections of readers’ letters in daily newspapers (N=10). They rated, for each of seven political parties, which percentage of the votes that they believed they would get in the election. They also marked which party they themselves preferred, and answered to a few questions about interest and competence. Data were then obtained on the outcome of the election, and on the two opinions polls closest in time to it. It was found that all four groups did reasonably well, when average prognostic judgments were compared to the outcome of the election, and better than the opinion polls. The two last polls overestimated the span between the incumbent government and the victorious opposition by a factor of 2. Wishful thinking was assessed by comparing prognostic judgments for each respondent’s preferred party with his or her judgments of other parties. All groups showed some wishful thinking; the political scientists least and the public most. There were large and consistent individual differences in prognostic ability. Men performed better than women, as did those who expressed more interest and knowledge in politics, but neither level of education nor confidence in making the judgments correlated significantly with performance.

Washington Post: The Top Pickers vs. the Pack - Sites Want Users to Buy Into the 'Genius' Factor, via Midas Oracle: What to think of all those Wisdom-Of-Crowds sites popping up like forest mushrooms after an October rain?
Cf: James Surowiecki "The Wisdom of Crowds" - kort beskrivning inför en eventuell bokbeställning

Posted by hakank at 07:07 FM Posted to Diverse vetenskap

november 01, 2006

Dagslänkar 2006-11-01

Klimatbloggen http://klimat.wordpress.com/2006/10/31/mediastorm-kring-bra-data/ om (påstådda) förändringar i golfströmmen. Diskussioner t.ex. på RealClimate.

Vetenskapsnytt: Rätt fokus ger bra målvakt

Point of Inquiry: CFI’s 10th Annual Houdini Seance - Halloween 2006
In this bonus episode of Point of Inquiry for Halloween night 2006, Joe Nickell, the world’s leading paranormal investigator and CSICOP’s senior research fellow, and D.J. Grothe (both of whom are former professional magicians) conduct CFI’s 10th Annual Houdini Seance. They also explore Houdini’s experiences as a “magician among the spirits,” recount the ways he challenged the mediums of his day, and discuss his lasting impact on skepticism and society’s beliefs about the afterlife.

Wired: Face Blind, via
Mind Hacks: Wired Magazine has an article on a curious condition known as prosopagnosia where affected individuals cannot recognise people by their faces, despite being able to recognise and distinguish everyday objects with little trouble....

Telegraph: How to be funny , via Mind Hacks.
Cf: Vitsen - en webbessä.

Low-complexity modular policies: learning to play Pac-Man and a new framework beyond MDPs:
In this paper we propose a method that learns to play Pac-Man...

Michael C. LaBarbera: The Biology of B-Movie Monsters, via Improbable Research

Seed Magazine: The Proof is in the Blogging, via Not Even Wrong.
Fortsättningen på den långa diskussion om ett matematiskt paper där paper-författaren snabbt tillkännagör att artikeln är felaktig och drog tillbaka den för komplettering.

Forecast of the 2006 U.S. House Election
If the U.S. Senate Elections were held on 01-Nov-2006...
Via Social Science Statistics Blog

Paul Ekman How to Spot a Terrorist on the Fly, via Deception Blog.

Ivars Peterson: Designer Decimals: Fractions can yield amazingly familiar decimal expansions.-

Posted by hakank at 10:44 EM Posted to Diverse vetenskap

oktober 21, 2006

Dagslänkar 2006-10-21

First Invisibility Cloak Tested Successfully, Scientists Say

Delwin T. Lindsey, Angela M. Brown Universality of color names
Cf: Color Names: More Universal Than You Might Think

Seung-Bae Cools, Carlos Gershenson, Bart D'Hooghe: Self-organizing traffic lights: A realistic simulation
We have previously shown in an abstract simulation (Gershenson, 2005) that self-organizing traffic lights can improve greatly traffic flow for any density. In this paper, we extend these results to a realistic setting, implementing self-organizing traffic lights in an advanced traffic simulator using real data from a Brussels avenue. On average, for different traffic densities, travel waiting times are reduced by 50% compared to the current green wave method.

Posted by hakank at 10:58 FM Posted to Diverse vetenskap

oktober 19, 2006

Dagslänkar 2006-10-19

The complete works of Charles Darwin. Det finns också Audio Darwin med MP3:or.

Freakonomics Born Again. Freakonomics i en bearbetad och utökad version. ISBN: 0061234001.

Arvind Narayanan, Vitaly Shmatikov:
How To Break Anonymity of the Netflix Prize Dataset
As part of the Netflix Prize contest, Netflix recently released a dataset containing movie ratings of a significant fraction of their subscribers. The dataset is intended to be anonymous, and all customer identifying information has been removed. We demonstrate that an attacker who knows only a little bit about an individual subscriber can easily identify this subscriber's record if it is present in the dataset, or, at the very least, identify a small set of records which include the subscriber's record.
A successful deanonymization of the Netflix dataset has possible implications for the Netflix Prize, which promises $1 million for a 10% improvement in the quality of Netflix movie recommendations. Given movie ratings of Netflix users who have made their ratings public, or perhaps obtained from public sources such as the Internet Movie Database (IMDb), a contestant may be able to identify their records in the Netflix dataset (if they are among the Netflix subscribers whose anonymized records have been released). With the complete knowledge of a subscriber's IMDb ratings, it becomes much easier to "predict" how he or she rated any given movie on Netflix.

Johans blogg-blogg: En karta över bloggosfärens mittpunkt
Hoppas Johan även gör en fin social nätverksanalys av detta.

Posted by hakank at 06:33 EM Posted to Diverse vetenskap

oktober 18, 2006

Dagslänkar 2006-10-18

Point of Inquiry: Richard Dawkins - The God Delusion
Point of Inquiry: Michael Shermer - Why Darwin Matters

"Vågen" fyller 25
It's 25, was begun by an SJSU alum, and is beloved. Or none of that

Today, the wave turns 25. And forgive the man widely recognized as its creator if he doesn't take the scientific analysis and heated arguments too seriously.

``It's just a fun little thing,'' said George Henderson, the 62-year-old professional cheerleader known as Krazy George, whose roots go back to San Jose State. ``And I'm glad I invented it.''

Via Improbable Research
Cf: Simulering av "Vågen", trafikfenomen och Crowd Dynamics

The ECLiPSe Constraint Programming System är nu Open Source. Kan laddas ner via Sourceforge
Cf kategorin Constraint Logic Programming.

Posted by hakank at 07:39 FM Posted to Diverse vetenskap

oktober 16, 2006

Lite länkar

Några länkar som sparats på Bloglines för att de befunnits intressanta och ska kikas (vidare) på.

Guardian Unlimited: Oh no, not Steely Dan again

Steven Levy really liked Steely Dan, but so too, it seemed, did his iPod. Like a lot of people, he began to wonder about its shuffle - was the random function really random or a result of dirty tricks, blunders... or even telepathy?

Cf:
Guardian Unlimited: The spice of life
Wikipedia: Shuffle

Russ Abbott: Emergence Explained

Emergence (macro-level effects from micro-level causes) is at the heart of the conflict between reductionism and functionalism. How can there be autonomous higher level laws of nature (the functionalist claim) if everything can be reduced to the fundamental forces of physics (the reductionist position)? We cut through this debate by applying a computer science lens to the way we view nature. We conclude (a) that what functionalism calls the special sciences (sciences other than physics) do indeed study autonomous laws and furthermore that those laws pertain to real higher level entities but (b) that interactions among such higher-level entities is epiphenomenal in that they can always be reduced to primitive physical forces. In other words, epiphenomena, which we will identify with emergent phenomena, do real higher-level work. The proposed perspective provides a framework for understanding many thorny issues including the nature of entities, stigmergy, the evolution of complexity, phase transitions, supervenience, and downward entailment. We also discuss some practical considerations pertaining to systems of systems and the limitations of modeling.

Peter Woit (Not Even Wrong):
Navier-Stokes Equation Progress?
En lång diskussion om ett matematiskt paper där paper-författaren snabbt tillkännagör att artikeln är felaktig och drar tillbaka den för komplettering.

The Probability That I Alone Will Decide an Election

Ivars Peterson: Pancake Sorting

MathFactor: (MP3 podcast):
Ett svar till "Which way leads out of the forest of Liars & Truth-tellers?" samt ett nytt problem.

Mind Hacks: Average girls are hot

Seed Magazine has an article on recent research published in Psychological Science that suggests that average faces are more attractive because they are easier for the brain to process.

....

Daniel Lemire, Owen Kaser:
One-Pass, One-Hash n-Gram Statistics Estimation

In multimedia, text or bioinformatics databases, applications query sequences of n consecutive symbols called n-grams. Estimating the number of distinct n-grams is a view-size estimation problem. While view sizes can be estimated by sampling under statistical assumptions, we desire an unassuming algorithm with universally valid accuracy bounds. Most related work has focused on repeatedly hashing the data, which is prohibitive for large data sources. We prove that a one-pass one-hash algorithm is sufficient for accurate estimates if the hashing is sufficiently independent. To reduce costs further, we investigate recursive random hashing algorithms and show that they are sufficiently independent in practice. We compare our running times with exact counts using suffix arrays and show that, while we use hardly any storage, we are an order of magnitude faster. The approach further is extended to a one-pass/one-hash computation of n-gram entropy and iceberg counts. The experiments use a large collection of English text from the Gutenberg Project as well as synthetic data.

Jurij Leskovec, Lada A. Adamic, Bernardo A. Huberman:
The Dynamics of Viral Marketing

We present an analysis of a person-to-person recommendation network, consisting of 4 million people who made 16 million recommendations on half a million products. We observed the propagation of recommendations and the cascade sizes, which can be explained by a stochastic model. We then established how the recommendation network grows over time and how effective it is from the viewpoint of the sender and receiver of the recommendations. While on average recommendations are not very effective at inducing purchases and do not spread very far, there are product and pricing categories for which viral marketing seems to be very effective.

Google Tech Talk. Nuno Vasconcelos: Using Statistics to Search and Annotate Pictures

Google Tech Talk. Karl Fogel: The Surprising History of Copyright and What It Means For Google

Google Tech Talk: David Pollak Ruby Sig: How To Design A Domain Specific Language

Timothy C. Marzullo, Edward G. Rantze,, Gregory J. GageMichigan, Ann Arbor
Stock Market Behavior Predicted by Rat Neurons (PDF)
Via Improbable Research

AustenBlog: 1940 PRIDE AND PREJUDICE to be released on Region 1 DVD October 10

numb3rs blog: Zero point energy, cycloids
Om senaste numb3rs-avsnittet (SE3,avsnitt 4 "Mole"). Spoilervarningar.
Cf:
numb3rs blog: Face Recognition Algorithms
Computational Complexity: Numb3rs of Collaborators

Statistics, Damn Statistics, and Lies

IEEE Spectrum: Modeling Terrorists

New simulators could help intelligence analysts think like the enemy.

NPR: Is String Theory Unraveling?

NPR's Scott Simon talks with "Math Guy" Keith Devlin about two new books that call into question the entire idea of string theory. The theory states that tiny vibrating strings make up everything, but some scientists say there is no way to prove or disprove it.

Cf följande två böcker
Peter Woit (bloggen Not Even Wrong, se även ovan)Not Even Wrong - The Failure of String Theory And the Search for Unity in Physical Law
Lee Smolin: Trouble With Physics

New Scientist: Do cancer cells cooperate with each other?

An analysis of how cells in a tumour cooperate has provided a unique insight into the evolution of cancer, and may lead to new treatments.

It makes use of "game theory" – the mix of mathematics and economics theory that has been invaluable in understanding how cooperation can evolve in animal societies, even when individuals are selfish.

Robert Axelrod, a political scientist at the University of Michigan in Ann Arbor, US, a leader in applying game theory to evolutionary biology, has now turned his attention to cancer.

Harvard University: A Celebration of the Achievements of Nobel Laureate: Thomas C. Schelling (video, kräver RealPlayer 10.5).

Damn Interesting: The Baader-Meinhof Phenomenon

Baader-Meinhof is the phenomenon where one happens upon some obscure piece of information– often an unfamiliar word or name– and soon afterwards encounters the same subject again, often repeatedly. Anytime the phrase "That's so weird, I just heard about that the other day" would be appropriate, the utterer is hip-deep in Baader-Meinhof.

Posted by hakank at 06:47 EM Posted to Diverse vetenskap

september 10, 2005

Några fler tankar om vidskeplighet, spel och datorprogram

Till gårdagens New Scientist: Spelare tenderar att vara mer vidskepliga än icke-spelare kommenterade både Wille på Prylfeber och Thebe på Trilog med tankvärda saker, vilket inte alls var oväntat. Här är några tankar kring detta, som p.g.a. längden upphöjdes till en egen bloggning.

Det bör noteras att begreppet "vidskeplig" nedan förändras en del efterhand.

Willes kommentar: vidskepelse i datorspel, och - visar det sig - i datorprogram överhuvudtaget
Wille ställde följande koncisa fråga

Undras om detta är applicerbart på oss som mestadels spelar dataspel med...

Det beror nog på vilken typ av spel det är frågan om. Är det ett rent skicklighetsspel med minimum av slump är det nog mindre risk för vidskepelsepåverkan. Är det däremot mycket slump inblandad eller många osäkra faktorer kan man nog vara i vidskepelseriskzonen.

Sedan bör man räkna med själva tävlingsmomentet som verkar göra det mer belagt med vidskepelserisk. Jämför med sport och andra former av tävlingar som alltså har större risk för vidskepelse. Stuart Vyse går igenom detta ordentligt i sin Believing In Magic - The Psychology of Superstition, se förra bloggningen för pek till bok och recension.

I nästan alla former av datorspel är det väl någon form av slump inblandad, t.ex. slumpgeneratorer som väljer ett motdrag före ett annat etc; detta skulle således även gälla schackdatorspel. Om inte annat så den (till synes) slumpmässiga blandningen av brickor (i 15-pussel), siffror (i Sudoku) eller liknande även om det sedan är frågan om ren skicklighet (samt kanske i viss mån av tur att man råkar hitta ledtrådar etc).

Vidskepelsen här kan vara av lite olika slag som är mer eller mindre rationella. T.ex. att man (tror att man) förlorar nästan alla spel när (och eftersom?) motståndaren först gör X, eller att id-numret för spelet är en udda siffra eller jämt delbart med 412, 42 eller 93112, eller att det är torsdag omedelbart före eller efter fullmåne (inom spelet eller utanför).

Går man lite vidare och utökar vidskepelse med "tro på magi", där "magi" motsvarar sådant som är mer eller mindre okänt kommer man in på andra intressanta saker.

Låt oss ta ett aktuellt exempel ur egen fatabur. Men tillåt mig först nämna att jag numera spelar väldigt lite datorspel, och de spel som i så fall tenderar att spelas är de konceptuellt enkla spelen, såsom Tetris (även om den en-dimensionella Tetris, Tetris 1D, kan bli lite tråkig i längden), en variant av 15-pusslet där man flyttar olikformade bitar (och som jag glömt namnet på just nu) etc. Som tidigare skrivits är Sudoku inte riktigt min kopp te (även om jag är intresserad av analyser kring spelet, t.ex. i nyhetsgruppen rec.puzzles. Strikt sett är Sudoku inte ett datorspel, även om det kan spelas på ett sådant.)

Och så det senaste tillskottet av dessa: Curve Ball som är ett Flashspel där man helt enkelt spelar någon form av tennis/pingis-match mot programmet, och där man kan skruva, studsa och hålla på. Skoj spel helt i min simpla smak, som till viss del kan förklaras av att jag i min ungdom spelade mycket pingis och hade som specialitet underskruvssmashar och liknande (men jag var inte speciellt jätteduktig i spelet).

Eftersom detta spel är helt utan manual (och om det skulle funnits någon vet jag inte om jag skulle bry mig) måste man lära sig de olika handgreppen genom att testa, testa, leka och testa (vilket för mig är det allra bästa sättet att lära mig datorprogram, trots bakgrund som just manualskribent).

Tyvärr innebär detta att man kan drabbas av en form av "vidskepelse" (kanske något vidare begrepp än ovanstående betydelse) genom att man kan få för sig att man måste göra si eller så för att få avsedd effekt, t.ex. att både göra en cirkelrörelse med musen och samtidigt klicka med vänster musknapp då man i själva verket endast behöver göra cirkelrörelsen.

Eller att man först måste gå bakom trädet och hämta guldet för att sedan gå in i huset och gömma det bakom kastrullerna för att sedan kunna skjuta det elaka monstret (ja, ni ser hur totalt ute jag är på nya datorspel :) men detta beteende är helt överflödigt. Ni som spelar mer moderna spel kan säkerligen ge bättre exempel (förhoppningsvis inte från egen erfarenhet).

Tyvärr tror jag att sådana beteenden inte bara gäller spelprogram utan vanliga program såsom ordbehandling och kalkylprogram, t.ex. att man (tror att man) först måste klicka med musen där för att sedan göra så etc, medan det räcker att göra så. Egentligen handlar det inte om att man inte har koll på alla kortkommandon utan att man blir "fast" i sin mentala modell över hur programmet fungerar.

För att koppla tillbaka till vidskepelse kring spel (gambling) så är det ju egentligen detta det är frågan om: att man har en felaktig modell hur verkligheten faktiskt fungerar. Sedan kan man kalla detta okunskap eller en dröm om en magisk värld.

Låt mig avsluta detta med Arthur C. Clarks lag: Any sufficiently advanced technology is indistinguishable from magic, dvs all tillräckligt avancerad teknologi går inte att skilja från magi.

En liten filosofisk utvikning om Curve Ball
Man kan f.ö. notera att Curve Ball är av synnerligen didaktisk natur eftersom det lär den ödmjuka sanningen att det man gör mot sina medmänniskor får man tiofalt tillbaka: dvs skruvar man eller framför allt studsar man på ett svårt sätt så är det stor chans att bollen kommer tillbaka på ett ännu svårare sätt. Ja, det var den enkla men viktiga lektionen.

Tyvärr är lösningen - och den är etiskt tveksam så låt inte era barn läsa vidare - att se till att smashen verkligen går in genom att t.ex. göra serve-ess eller spela snällt en stund och sedan dänga till bollen i krysset eller en fet underskruvs-studs-smash. Så vill jag inte att vi ska leva våra liv tillsammans.

På lite högre nivåer - säg från nivå 7 eller 8 - blir det ett förfärligt studsande och mindre möjligheter att spela finlir.

Tack till Bengt (på Frihetens Vingar) som gjorde mig underkunnig om spelet förra helgen och för en trevlig Talk-stund om bl.a. ovanstående igår.

Thebes kommentar om vidskepelse vs kunskap om sannolikhetsteori
Thebe skrev följande i sin kommentar:

Jag tror, taget ur luften, men precis som du är inne på, att vidskepelse ersätter det "hokus-pokus" som sannolikhetsteori beskriver. Dvs, om man ritar ett xy-diagram med "vidskepelse" på y-axeln och "kunskap i sannolikhetsteori" på x-axeln så kommer man få en linje med negativ lutning, den kanske t o m är logaritmiskt, typ y = -ln(x) eller något i den stilen!

Men, sen finns ytterligare ett litet problem med sannolikheter även om man känner sig trygg med hur det funkar ... och det är ju att man aldrig i det enskilda fallet kan säga något om utfallet. Vilket skulle kunna förklara ett slags möjlig vidskepelse-bias hos _alla_.

Thebe gör - som vanligt - en härlig matematisk koppling till problemen. Jag håller naturligtvis med att kunskap om sannolikhetsteori minskar risken för vidskeplighet även om den - som Thebe så rikigt skriver - troligen aldrig blir 0 (noll). T.ex. kan en spelteoretisk modell vara fel och man riskerar då att ersätter en felaktig vidskeplig "vardagsmodell" med en annan men mer lärd men ändå "vidskeplig" modell. Man bör dock notera att det normalt ses som mer rationellt att tro på den sannolikhetsteoretiska (men här felaktiga) modellen än vardagsmodellen.

Ett möjligt exempel på en sådan lärd men vidskeplig modell kan vara den tekniska analysen inom aktiehandel. Vissa hävdar att sådan analys, eller delar av den, är inget annat är skrock eller data snooping, dvs där man letar efter samband i efterhand och tror att man kommit på något listigt. (Här någonstans borde man kunna rekommendera boken Fooled by Randomness av Nassim Taleb som diskuterar liknande saker. En väldigt trevlig bok är det.)

Jag håller helt med om att vi aldrig är helt immuna mot olika former av vidskepelser. Det bästa motemedlet är nog att emellanåt vara medveten om att alla våra beteenden och/eller vår kunskap kan vara utsatta för vidskepligheter i en eller annan form.

Posted by hakank at 09:29 FM Posted to Diverse vetenskap | Skepticism, parapsykologi etc | Comments (5)

september 09, 2005

New Scientist: Spelare tenderar att vara mer vidskepliga än icke-spelare

New Scientist-artikeln Gamblers are a superstitious bunch berättar om en undersökning kring spelares (specifikt bingospelare) vidskepelse. Denna visar att (bingo)spelare tenderar vara mer vidskepliga än icke-spelare.

Gamblers are significantly more superstitious and place more importance on so-called "lucky events" than the larger population, according to new research.

Over 80% of UK bingo players surveyed were generally superstitious - some attributing lucky seats, lucky friends and lucky nights of the week to gambling success.

Just one-third of the larger UK population are thought to be superstitious - the most commonly reported behaviours being: avoiding walking under ladders, touching wood for good luck and throwing salt over shoulders.

Superstition is a belief that a given action can bring good luck or bad luck even when there are no rational grounds for that belief, explains Mark Griffiths, professor of gambling studies at Nottingham Trent University, UK.

Sagde Mark Griffiths och Carolyn Bingham har skrivit om detta i A study of superstitious beliefs among bingo players (PDF). Artikeln publicerades i Journal of Gamling Issues.

Orsakssamband mellan spel och vidskepelse
Man kan fråga sig om orsakssambandet mellan spelande och vidskepelse: Blir man lättare en spelare om man är vidskepligt lagd eller tenderar spelandet att skapa ett vidskepligt beteende?

Själv vet jag inte (och jag är varken speciellt vidskeplig eller spelare). En intution kring detta är att spelande troligen förstärker vidskepelse, speciellt om man inte riktigt har koll på hur märklig slumpen kan te sig och läser in samband där samband inte finns. Några vanliga sådana felslut är "spelarens felslut" (se t.ex. gambler's fallacy från skepdic och Gambler's Fallacy från eng. wikipedia), och att se kluster där sådana inte finns: Clustering illusion, eng. wikipedia).

Se även Recension: Stuart Vyse 'Believing in Magic - The Psychology of Superstition' som recenserar en utmärkt bok om vidskepelse. Vyse skriver bl.a. även att arbeten där slump eller osäkerhet av olika slag spelar stor roll, tenderar att skapa vidskepelse, såsom skådespelare, utövare av sport etc. (Tenderar spelare på börsen att vara vidskepliga?)

Kategorin Sammanträffanden innehåller bloggningar om näraliggande ämnen.

Posted by hakank at 06:56 FM Posted to Diverse vetenskap | Sammanträffanden | Comments (3)

juni 13, 2005

Dual photography

Titeln på New Scientist-artikeln Card trick holds promise for movie effects fångade naturligtvis mitt intresse. Korttrick och filmeffekter?

Det visade sig handla om en fotografisk teknik "Dual Photography" som möjliggör en massa roliga saker (som en som jag icke insatt i dessa saker benämner det). Från New Scientist-artikeln:

A card trick to flummox even the most expert of conjurers could hold the key to unparalleled trick photography and special effects.

Researchers from Stanford University in California and Cornell University, New York, both in the US, have demonstrated a way to identify a playing card whose face is turned away from the camera. They did it by measuring projected light as it bounced off the face of the card and one other surface before reaching a camera.

Key to the conjuring trick is a technique known as "dual photography". This involves retracing the path light takes as it bounces off different surfaces, pixel by pixel. A light projector - with millions of controllable pixels which are switched on in turn - illuminates the scene. The reflected light from each pixel is recorded sequentially by a digital camera.

Papret som refereras är
Pradeep Sen, Billy Chen, Gaurav Garg, Stephen R. Marschner, Mark Horowitz, Marc Levoy, Hendrik P. A. Lensch: Dual Photography (stor fet PDF, cirka 20Mb).

Det finns även en MP4-fil (cirka 63 Mb). Det omtalade "korttricket" är det sista som visas.

Posted by hakank at 09:05 EM Posted to Diverse vetenskap

april 26, 2005

Johan Asplund "Genom huvudet" (några andra av Asplunds böcker nämns och rekommenderas också)

Genom Huvudet: Problemlösningens socialpsykologi (ISBN: 9173744034) av Johan Asplund är en underbar bok som till ytan analyserar lösning av problem (gåtor) men har en underström (eller är det en överström?) av en stark kritik av både kognitiv psykologi och traditionell AI för att dessa endast studerar de mänskilga förmågorna isolerat från de sociala sammanhangen där förmågorna verkar.

Lösning av de konstruerade gåtor som Asplund främst behandlar är i och för sig rätt speciella genom att de har vissa typiska drag som mer naturlig problemlösning (t.ex. en nobelpristagares forskning) oftast saknar:

* det finns en mänsklig konstruktör av gåtan
* det finns någon som presenterar gåtan som en gåta
* problemlösaren inser oftast snabbt att det är en gåta och ställer sig s.a.s. i gåt-mode.
* en gåta behåller man inte utan den är till för att ges bort, det är en gåva (underbart!). Varpå den som tidigare var gåt-mottagare nu blir gåt-givare.

Här visar sig alltså den sociala dimensionen av gåtlösningen. Denna typ av problemlösning är inget som sker isolerat - endast "genom huvudet" - på en person utan är ett intrikat samband mellan flera personer (roller).

Det finns också vissa förväntningar hur man ska bete sig som problemlösare. Asplund menar att ingen egentligen förväntar sig att dessa gåtor ska lösas, eftersom man har väldigt kort tid på sig att komma med ett rätt svar eller gissa (typ 10-20 sekunder). Skulle gåtan verkligen lösas blir gåtställaren besviken, och på något sätt är det sociala mönstret brutet. Min egen erfarenhet av gåtlösning är något annorlunda. De gåtor som jag faktiskt löser kan ta både kortare och lite längre tid att lösas, men nog katten ska de lösas. [Skillnaden mellan våra synsätt kan vara att Asplunds gåtor/svar levereras direkt mellan två personer, t.ex. i en frisörsalong, medan de gåtor jag tenderar att försöka lösa fås via mera indirekta medium såsom webb eller mail där gåt-givaren troligen inte har sådana förväntningar på direkt respons.]

Ovanstående struktur påminner mycket om vitsens vilket Asplund nämner i förbigående men går tyvärr inte djupare in på detta. Det kanske kommer i en senare bok? En skillnad som jag ser det är att vitsar mer sällan "löses" så medvetet som gåtor, men annars finns det stora likheter i både den tekniska och den sociala strukturen hos dessa två konstarter.

Asplund diskuterar inte bara gåtor utan vidgar diskussionerna till att gälla schack, som ses som ett socialt spel med många gemensamma drag av gåtlösning. Inte heller i schack löser man problem isolerat, endast "i huvudet". Man måste hela tiden ha en motståndare och dennes möjliga strategier i tanken när man planerar sitt nästa drag. En bra poäng: Om båda spelarna visste de bästa dragen i samtliga positioner vore schack förfärligt tråkigt.

Ett av bokens trevligaste kapitel är kritiken av AI:s isolationism, där framförallt två saker diskuteras: Turing testet (en riktigt länksamling finns här) som är en av (traditionell) AI:s stora hörnpelare och Searles tankeexperiment med Det kinesiska rummet.

När jag först blev uppmärksam på boken trodde jag den skulle vara sprängfylld med olika gåtor och tips hur man löser dem. Det är den inte, det är helt enkelt inte en sådan bok.

(En betydlig kortare version av denna recension finns att hitta för den som söker.)

Gåtor och Asplund är två begrepp som hör tätt ihop - i alla fall i mitt huvud - sedan han skrev Om undran inför samhället (Bokuslänk, ISBN: 9170060002) där flera exempel på social forskning och dess problem förklaras med just gåtor. "Om undran ..." påverkade mig mer än vad jag ofta inser, t.ex. genomgången av aspektseende (som i och för sig en gammal kursbok Jan Andersson och Mats Furberg Språk och påverkan också betonande) och lösningen av "gåtor". Här diskuteras både sociologiska teorier och pusseldeckarnas sätt att lösa problem, i en synnerlig salig blandning. Ett speciellt påverkansfullt kapitel var analysen av Marcel Duchamps tavla (La mariée mis à nu par ses cëlibataires, meme, vilket översätts till "Bruden avklädd av sina ungkarlar"). Denna bok rekommenderar naturligtvis också.

Asplund är en sådan där som ställer de intressanta frågorna och sådant fascineras jag alltid av. Läs här bara hur han börjar sin Om hälsningsceremonier, mikromakt och asocial pratsamhet (min emfas):

Antag att du råkat i konflikt med din granne. Ni har försökt att lösa konflikten med misslyckats. Er tidigare vänskap har förbytts i ovänskap. Dock stöter ni fortsättningsvis jämt och ständigt på varandra; ni möts vid tomgränsen, på gatan osv. På vilket sätt framgår det av dessa konfrontationer att du och din granne numera är ovänner? Den frågan kan med största lätthet besvaras av var och en. Att ni är ovänner framgår av att ni har slutat hälsa på varandra.

Hur gör man när man låter bli att hälsa på sin granne?

Posted by hakank at 07:53 EM Posted to Böcker | Diverse vetenskap | Husgudar | Comments (5)

mars 03, 2005

Musik "operated by nature"

Jag fick ett mail angående Inf@Vis: Visualising Music med en fråga om jag visste någon som gör musikinstrument "operated by nature". (Frågan är inte riktigt kopplat till anteckningen, den som mailade sökte på music blogg och råkade komma hit. Troligen är "blogg" ett stavfel.)

Om man märker ord så är väl alla musikinstrument "operated by nature", t.ex luft som swischar eller strängar som svänger på ett visst sätt. Men frågan avser såvitt jag förstår snarare musikinstrument som skapar musik utan direkt mänsklig inblandning (förutom möjligen att ha konstruerat maskinen). Elförstärkt eller datorgenererad musik räknar jag inte till denna kategori.

Jag kan tänka mig feta orgelpipor som står ute på en blåsig hed och ljudar allt efter vinden fångas i piporna, eller en harpa några meter till vänster på samma hed precis bredvid en buske (eller under ett vattenfall). Kanske den där klädnypan på ett cykelhjul är ett embryo till vacker musik?

Dock känner jag inte till några specifika installationer. Är det någon som vet mer om detta?

Posted by hakank at 07:57 FM Posted to Diverse vetenskap | Comments (2)

februari 28, 2005

Nicklas Lundblad: Föreläsning "Kniv, Gaffel och Internet - När Internet slutar vara teknik"

Nicklas Lundblad, direktör på Stockholms Handelskammare och tillika Kommenterat-bloggare, höll idag en skiftesföreläsning på Malmö högskola: Kniv, Gaffel och Internet - När Internet slutar vara teknik" (föreläsnings-PDF).

En bild av den trollbundna publiken finns här, där man kan - om man kisar lite till höger - se Erik Starck (Framtidstanken), Åsa och underbloggad i omvänd ordning.

Några korta kommentarer och nedykningar. Reservation för förenklingar, ofullständighet och missförstånd. Jag hoppas att Erik kommer kommentera föredraget mer ingående av vad som görs här nedan.
Uppdatering: Erik har skrivit sin version av föredraget i Skiftesföreläsning med Nicklas Lundblad.

Det var en inspirerad föreläsning där Nicklas rätt snabbt gick igenom då-vs-nu av Internet/Nätet, den personliga integriteten och yttrandefriheten satt i sina historiska ramar. Med den nya tekniken och de möjligheter som finns måste vi ovärdera de gamla begreppen.

Några begrepp att fundera och ev. kolla in lite mer:
* Splinternet: Från Internets och webbens första stapplande steg och stora visioner om ett öppet (informations-)samhälle, blir det mer och mer splittrade delnät. De typer av nät som ökar mest är de privata, dvs de låsta rummens nät dit endast de invigda får en nyckel.

* Det transparanta samhället (David Brin The Transparent Society, Benthams Panopticon) vs Brussamhället: Öppenheten och den myckna informationen som finns på nätet gör att Storebror inte har någon möjlighet att bevaka alla medborgare. Däremot möjliggör det att enskilda personer kan övervakas lättare.

* Brusgränsen: "När värdet av informationen är mindre än värdet av tiden det tar att hitta den!". Det gäller alltså att veta 1) hur man använder sökmotorer och andra informationscentraler och 2) att veta när man det inte går att hitta mer (om ens något) om en viss sak.

* Pseudonymer: Fler och fler använder konsekvent pseudonymer (anonymer?) och kan därigenom hög status/tillit utan att andra vet vem personen egentligen egentligen är. (Cf. Lite mer om trust/reputation samt peer-to-peer.)

* Informationens växande. Nicklas visade utvecklingen av :s portal från 1996 till 2005, från den enkla bilden till den nuvarande kompl(exa|icerade) sajten. Kom då att tänka på Jon Udells underbara förevisning av ett Wikipedia-ords utveckling Heavy Metal Umlaut - The Movie.

* Integritet: Nicklas omdefinerar - eller åtminstone problematiserar - begreppet "integritet". Vad kan egentligen integritet betyda i en värld full av information om alla? Vad jag försod är Nicklas förslag att alla har rätt att bli sedda i sin helhet, inte bara delar.

* Bloggarnas uppgång och fall. Där "uppgång" är de nya möjligheter till mediegranskning och demokratisering som bloggar och dess snabba nätverk kan utgöra.

Och "nedgång" är den fullständigt explosion av nya bloggar som kommer dagligen. Hur ska man hålla reda på alla? Alla bloggar blir inte lästa, utan endast ett fåtal, dvs samma uppdelning som för mer traditionell media. Fördelen med bloggar, speciellt som informationfilter, är att det är lättare att själv välja och skapa sin egen mediebild.

Brusifieringen av bloggar med reklam och otydliga avsändare/agenda, som exempel togs Scobleizer upp.

* Nicklas avslutar med följande: "När vi slutar betrakta nätet som teknik kommer de frågor vi ställer att vara mycket annorlunda från de frågor vi ställer idag."

Posted by hakank at 10:36 EM Posted to Diverse vetenskap | Comments (5)

februari 07, 2005

Inf@Vis: Visualising Music

Inf@Vis: Visualising Music:

Music has been made to hear and feel it. Musical notation added a certain way to visualise it, but we have never had so many possibilities to see its structure and the nature of the relations between its styles and individual pieces as we have today.

Posted by hakank at 08:24 EM Posted to Diverse vetenskap

februari 06, 2005

Philip Ball: Freudian quips (om matematikers humor)

I Nature-artikeln Freudian quips skriver Philip Ball om matematikers humor.

If, therefore, Freud was right to claim that jokes relieve anxiety by releasing suppressed feelings, mathematicians' jokes betray a deep-seated worry about whether their proofs are, so to speak, big enough. A humorous 'guide for lecturers' outlines the many different kinds of proof available.

Papret som refereras till i artikeln är
Paul Renteln, Alan Dundes: Foolproof: A Sampling of Mathematical Folk Humor (PDF).

Se även
Några böcker om vitsar med anledning av en The New Yorker-artikel
Vad är en vits?

Posted by hakank at 12:16 EM Posted to Diverse vetenskap | Humor | Matematik | Comments (3)

januari 05, 2005

Vacuum Card Deck

Vacuum Card Deck är en Oblique Strategies-inspirerad wiki av "52 cards of conversation starters". Några exempel:
How do you keep track of birthdays?
What software do you think in?
Take advantage of weak ties

Flera av dessa har diskuterats i Yahoo!-gruppen vacuum-egroup som har följande programförklaring: How can people organize in their minds and personal interactions information about a network so large that strains the limits of the imagination? Vacuum tries to provide insight, tools, and clues to find out.

Se även:
Edward Vielmetti, hans blogg Vacuum

Brian Eno's Oblique Strategies slumpgenerator

Posted by hakank at 08:48 EM Posted to Diverse vetenskap

november 16, 2004

Sociophysics

RedNova News: Psychohistory is Coming: Scientists Learning to Take Society's Temperature:
A little over half a century ago, Isaac Asimov created a new universe, home to a decaying galactic empire and a novel form of social order known as the "Foundation."

Asimov's "Foundation" novels - the most famous science-fiction trilogy between "Lord of the Rings" and "Star Wars" - described a new science of social behavior called psychohistory. Mixing psychology with math, psychohistory hijacked the methods of physics to precisely predict the future course of human events.

Today, Asimov's vision is no longer wholly fiction. His psychohistory exists in a loose confederation of research enterprises seeking equations that capture patterns in human behavior. These enterprises go by different names and treat different aspects of the issue. But they all share a goal of better understanding the present in order to foresee the future, and possibly help shape it.
...
Among the newest of the enterprises - and closest to the spirit of Asimov's psychohistory - is a discipline called sociophysics. The name has been around for decades, but only in the 21st century has it become more science than slogan.

Like Asimov's psychohistory, sociophysics is rooted in statistical mechanics, the math used by physicists to describe the big picture when lacking data about the details. Nobody can track the trillion trillion molecules of air floating around in a room, for instance, but statistical mechanics can tell you how an air conditioner will affect the overall temperature.

In a similar way, science cannot describe how any given individual will behave. But put enough people together, Asimov's psychohistorian Hari Seldon reasoned, and laws of human interaction will produce predictable patterns - just as the way molecules move and interact determines the temperature and pressure of a gas.
...
"We're sort of working on little bits of it, trying to make connections," says Princeton University's Joshua Greene, a philosopher and neuroscientist.

"The idea is really to have, in the end, a seamless understanding of the universe, from the most basic physical elements, the chemistry, the biochemistry, the neurobiology, to individual human behavior, to macroeconomic behavior - the whole gamut seamlessly integrated," he says. "Not in my lifetime, though."

(Via Social Capital Reading Stack.)

Mer om sociophysics:
Sociophysics: Theory, Resources, Quantification, News
Serge Galam: Sociophysics: a personal testimony
The origins of Sociophysics are discussed from a personal testimony. I trace back its history to the late seventies. My twenty years of activities and research to establish and promote the field are reviewed. In particular the conflicting nature of Sociophysics with the physics community is revealed from my own experience. Recent presentations of a supposed natural growth from Social Sciences are criticized.

Posted by hakank at 07:28 EM Posted to Diverse vetenskap

november 13, 2004

En lite längre länklista

Efter en längre tids lågbloggande krävs åter rengöring i Bloglines-tanken. För enkelhets skull har delar av informationstraverseringen lämnats ofullständig. Det kan här nämnas att vid slika lågbloggningstider tenderar aktiviteten på hakank's bloglines blog att öka. Möjligen förekommer det viss överlappning mellan bloggarna men det kan nog välvälliga läsare förlåta efter rimlig betänketid.

Edward L. Glaeser, Giacomo A. M. Ponzetto, Jesse M. Shapiro: Strategic Extremism: Why Republicans and Democrats Divide on Religious Values (PDF)
Abstract:
Party platforms differ sharply from one another, especially on issues with religious content, such as abortion or gay marriage. Religious extremism in the U.S. appears to be strategically targeted to win elections, since party platforms diverge significantly, while policy outcomes like abortion rates are not affected by changes in the governing party. Given the high returns from attracting the median voter, why do vote-maximizing politicians veer off into extremism? In this paper, we find that strategic extremism depends on an important intensive margin where politicians want to induce their core constituents to vote (or make donations) and the ability to target political messages towards those core constituents. Our model predicts that the political relevance of religious issues is highest when around one-half of the voting population attends church regularly. Using data from across the world and within the U.S., we indeed find a nonmonotonic relationship between religious extremism and religious attendance.

Spelteoretiska övningar med exempel från bl.a. Riddarfalken från Malta: Crescat Sententia: The Kick-him-'cause-he's-down equilibrirum samt confessing error, standing pat

Wikipedia: Organic Poetry:
OrganicPoetry is a game for social transformation by bringing people together in a collaborative manner. While based on complex ideas in game theory, conflict resolution, social networking and control theory, the game is extremely simple, because the players make up the rules as they play along.
...
Summary: A powerful tool, OrganicPoetry can be used in political advocacy, and in bringing people and communities together for a cause, to seduce your lover, or just to have some non-competitive fun at a party.
Jämför gärna med Sheep are sprayed with words to create poetry

Wikipedia: Birthday paradox:
The birthday paradox states that if there are 23 people in a room then there is a slightly more than 50:50 chance that at least two of them will have the same birthday. For 60 or more people, the probability is greater than 99%. This is not a paradox in the sense of it leading to a logical contradiction; it is a paradox in the sense that it is a mathematical truth that contradicts common intuition. Most people estimate that the chance is much lower.

Marginal Revolution: Quantum Game Theory samt Quantum Game Theory, Revisited som sedan följdes av en rätt intensiv diskussion, se t.ex. backtrack-länkarna i anteckningarna.
Och se även Let the quantum games begin från Physics Web, oktober 2002.

Spelteori och terrorism
Foreign Dispatches: The Game Theory of Terrorism
en uppföljning på Sock Thief: Game Theory and Terrorism med lite länkar till papers, t.ex. Terrorism and Game Theory av Todd Sandler och Daniel G. Arce

Cornell News: Why thin, flat things rise and glide on the way down: physicists finally solve the falling-paper problem .
Papret som refereras är Jane Wang: "Falling Paper: Navier-Stokes Solutions, Model of Fluid Forces, and Center of Mass Elevation", Phys. Rev. Lett. *93*, 144501 (2004). En abstract finns här.

Blog-a-Bing: Don't trust me: I make use of people

Apropå Nya rön i fångarnas dilemma - lite länkar:
Agoraphilia: Rumors of Tit-for-Tat's Death Greatly Exaggerated, Freedom to Tinker: Tit for Tat.

Technologic: What are the Foundations for Trust in Online Interaction?
Was trust originally established because eBay instilled confidence by asserting rules of conduct for buyers and sellers? Were the requirements stipulated by the individual sellers on their auctions also responsible for establishing trust? Was it the promptness to email questions, the layout and presentation of the sales page, or the description of the item being sold that instilled confidence?

Charles Roxburgh Hidden flaws in Strategy (The McKinsey Quarterly, 2003 Number 2)
After nearly 40 years, the theory of business strategy is well developed and widely disseminated. Pioneering work by academics such as Michael E. Porter and Henry Mintzberg has established a rich literature on good strategy. Most senior executives have been trained in its principles, and large corporations have their own skilled strategy departments.

Yet the business world remains littered with examples of bad strategies. Why? What makes chief executives back them when so much know-how is available? Flawed analysis, excessive ambition, greed, and other corporate vices are possible causes, but this article doesn’t attempt to explore all of them. Rather, it looks at one contributing factor that affects every strategist: the human brain.

Catherine A. Johnson: Choosing people: the role of social capital in information seeking behaviour
It is an almost universal finding in studies investigating human information behaviour that people choose other people as their preferred source of information. An explanation for the use of people as information sources is that they are easier to approach than more formal sources and therefore are a least effort option. However there have been few studies that have investigated who the people chosen as information sources are and what their relationship to the information seeker is. This paper reports findings that come out of a larger investigation of the information seeking behaviour of a random sample of residents of Ulaanbaatar, Mongolia. Using the theory of social capital as a conceptual framework and the methods of social network analysis, this study investigated the relational factors associated with the choice of people as information sources. Results indicate that respondents chose people who had better resources than they had and were not well known by them. This suggests that respondents were deliberate in their choice of people information sources and therefore it is speculated that people are not necessarily the least effort option but may require considerable effort to seek out and consult.

Crossroads Dispatches: Blogs as Truth-Telling Networks

Connectedness: What is social capital and how do we measure it?

MathWorld: Seven Mathematical Tidbits

JUNG 1.5 har släppts.
JUNG provides a common and extendible language for the modeling, analysis, and visualization of data that can be represented as a graph or network. Features in this release include: new visualization features (updated VisualizationViewer, new PluggableRenderer, and SpringLayout to make them more flexible and powerful; take a look at PluggableRendererDemo), new clustering and ranking algorithms, new vertex mapping mechanisms, new ways of reporting and diagnosing constraint violations, numerous new decorators and predicates; a number of improvements in usability and function to existing classes (including GraphML and Pajek I/O), and a number of bug fixes, including extensive revisions to the Barabasi preferential-attachment graph generator. Also now using COLT 1.2 (whose new license requirements should free JUNG for use in commercial development) and Commons-Collections 3.1.
Se även JUNG: ett Java-ramverk för graf-/nätverksanalys.

Philip Ball: Trains get fluffy
Superfast trains of the future could glide over fluffy tracks like snowboarders over snow, say US researchers. The same principle could be used to develop low-friction, long-lived bearings for machinery with moving parts.

Mathematics and Sex (utdrag från och kommentarer av en Salon-artikel).

Explainer: Epidemics in Small Worlds

Craigs List Personals and the Market for Lemons
I think this model [George Ackerlof's Market for Lemons] relates really well to Craigs List personals. Because the norm is for personal posters not to post a picture on this site and very limited information about themselves, people who have above average appearences and personalities go elsewhere to find dates. The market quickly unravels and you end up with either a girl who can't find a man anywhere else with a man that treats her like shit, a man who can't get find a date anywhere else and finds a woman who treats him like shit, or you get two very low quality people who can't find dates anywhere else and end up together. Other dating sites where you post much more informaation and is much less anonymous have a chance of working better for those who don't want one of three possible matches. Even better is meeting somebody without the use of personal ads.

Kimmo Eriksson, Jonas Sjostrand, Pontus Strimling: Optimal stopping in a two-sided secretary problem
In the "secretary problem", well-known in the theory of optimal stopping, an employer is about to interview a maximum of N secretaries about which she has no prior information. Chow et al. proved that with an optimal strategy the expected rank of the chosen secretary tends to approximately 3.87.
We study a two-sided game-theoretic version of this optimal stopping problem, where men search for a woman to marry at the same time as women search for a man to marry. We find that in the unique subgame perfect equilibrium, the expected rank grows as the square root of N and that, surprisingly, the leading coefficient is exactly 1. We also discuss some possible variations.
"The Secretary Problem" kallas även "The Sultan's Dowry Problem". Se t.ex. The Secretary Problem.

Freshmeat: poker-eval 124.0
poker-eval is a C library to evaluate poker hands. The result of the evaluation for a given hand is a number. The general idea is that if the evalution of your hand is lower than the evaluation of the hand of your opponent, you lose. Many poker variants are supported (Draw, Holdem, Omaha, etc.) and more can be added. It is designed for speed so that it can be used within poker simulation software using either exhaustive exploration or Monte Carlo.

An Open Challenge to Nassim Taleb from Hamilton, en diskussion om och med Nassim Talem, bland annat om den trevliga boken Fooled by Randomness: The Hidden Role of Chance in Life and in the Markets. Se även Edge Learn to expect the Unexpected.

Skeptical Inquirer Volume 28, Number 5, September/October 2004

Jakob Nielsen: User Education Is Not the Answer to Security Problems

Frisim: Kod-sökmotorn Koders.com

Minding the Planet: Great Article on Psychohistory and Sociophysics -- Can We Predict Behavior?

Minding the Planet: Just saw Primer, om indie sci-fi-filmen Primer som verkar skoj.

Freedom to Tinker: Bad Protocol
Dan Wallach from Rice University was here on Monday and gave a talk on e-voting. One of the examples in his talk was interesting enough that I thought I would share it with you, both as an introductory example of how security analysts think, and as an illustration of how badly Diebold botched the design of their voting system.

Joi Ito: How not to make YAPSN

generation5:
Cities as Complex Adaptive Systems
Self Organizing Map AI for Pictures
Using Bugs and Viruses to Teach Artificial Intelligence

Clay Shirky:
Social software as a term
Blogging as activity, blogging as identity

Eric Rasmusen: Voting Cycles: A Game Theory Problem
Unifying Ideas in Game Theory: Symmetric-Player Games vs. Principal-Agent Games
Do Markets Cure Consumer Mistakes? Schwartz paper
Trust Game

Crescat Sententia: Sin , om Deirdre McCloskeys Secret Sins of Economics (PDF).

Arrow's Theorem
Arrow's theorem is one of the most influential discoveries in electoral theory.

Data Mining in Politics

Mathematics and Music

The Fight Against Spam, Part 2

George A. Miller The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information (klassiker från 1956)

Counting on the future
It's almost ten years since the most famous mathematical puzzle of all time – known as Fermat's Last Theorem - was solved after more than three centuries of tantalising and torturing the world's most gifted mathematicians. Now, two more major conundrums may be about to crumble. So is mathematics in a golden age or is it, in fact, in decline? If you listen to mathematicians, "both" may be the correct answer.

Posted by hakank at 11:05 FM Posted to Diverse vetenskap

John Allen Paulos: Complexity, Randomness and Impossible Tasks

I John Allen Paulos senaste kolumn Complexity, Randomness and Impossible Tasks: A Mathematical Approach to Understanding Complexity diskuteras komplexitet och de näraliggande begreppen ordning och slump.

Some things are simple, some are complicated. What makes them so? In fields ranging from biology to physics to computer science, we're often faced with the question of how to measure complexity.

The flavor of the subject can perhaps be sampled by considering this question: Why is it that the first sequence of 0's and 1's below is termed orderly or patterned and the second sequence random or patternless? (Note that since almost everything from DNA to symphonies to this very column can be encoded into 0's and 1's, this is not as specialized a question as it may at first appear.)

(A) 0010010010010010010010010010010010010010010 …

(B) 1000101101101100010101100101111010010111010 …

Answering this question leads not only to the definition of algorithmic complexity, but also to a better understanding of (a type of) randomness as well as a proof of the famous incompleteness theorem first proved by the Austrian mathematician Kurt Godel.

Hang on. The ride's going to be bumpy, but the view will be bracing.

Att t.ex. vidare se:
G J Chaitin Home Page
Andrey Nikolaevich Kolmogorov (biografi)
Kolmogorov Complexity and Solomonoff Induction

Posted by hakank at 09:03 FM Posted to Diverse vetenskap

november 12, 2004

Diverse länkar med ett tema samt en TUNPMÄÄ

Diverse länkar som hittade efter en sökning på Looksmart: Find articles. Det finns ett tema, och det kan vi väl ha som en liten TUNPMÄÄ (Tävling-Utan-Något-Pris-Mer-Än-Äran) att lista ut. Det torde inte vara så svårt, men vilket var det exakt sökordet den exakta sökfrasen (se kommentar nedan) som användes? (Not: Åtminstone en av artiklarna har länkats till tidigare, fast då var det till originalkällan).

Judith Stone: Leisure pursuits - how scientists relax
E. Klarreich: Toss out the toss-up: bias in heads-or-tails
Ivars Peterson: Inside averages; from x-ray tomography to Plato's books, mathematicians are uncovering secrets hidden in averages - includes 2 related articles on a box of averages and analyzing syllable patterns in Plato's books
Edward F Kelly: Contra George Hansen's flawed critique of the work with B.D - research subject Bill Delmore - response to George P. Hansen, Journal of Parapsychology, in this issue, p. 307
Kevin McKean: The orderly pursuit of pure disorder - random numbers
Ivars Peterson: Pick a sample: learning statistics - minus the frustrations - new computer-based techniques for teaching college-level statistics
Kendrick Frazier: A mind at play: an interview with Martin Gardner - author of mathematics and science books - Interview

En bonuslänk (där sökordet ändrades enligt standard webbeteende och som är således utanför temat, fast kanske inte så mycket egentligen):
Erica Klarreich: Bookish math: statistical tests are unraveling knotty literary mysteries - stylometry

Uppdatering
Ersatte "sökordet" med uttrycket "sökfrasen" för att inte förvirra - eller kanske just därför.

Posted by hakank at 11:22 EM Posted to Diverse vetenskap

Benoit Mandelbrot intervjuad i New Scientist: A fractal life

New Scientist har en intervju med Benoit Mandelbrot: A fractal life

What is it like seeing the Mandelbrot set emblazoned on T-shirts and posters?

I'm delighted. I always felt that science as the preserve of people from Oxbridge or Ivy League universities - and not for the common mortal - was a very bad idea.
...
Fractals seem to appear all over nature and in economics. Even the internet is fractal. What does that say about the underlying nature of these phenomena?

Well, it depends on the field. Circles and straight lines also appear everywhere. Does this mean that all those phenomena have something in common? Of course not. The roughly circular trajectory of a planet around the sun is due to gravitational interactions. Berries are round because a sphere has a smaller skin. The beauty of geometry is that it is a language of extraordinary subtlety that serves many purposes.
...
Do better theories [about world wide finance] really matter, though?
Financial risks are much underestimated. The effects of wrong business decisions are global. Nobody takes realistic measurements of risk and we should. I think we should take a strongly conservative attitude towards evaluating risks. I have lived all my life skating on thin ice, which does make you conservative. I've met stockbrokers who say that they are perfectly happy that they have judged the financial risks correctly in 95 per cent of their cases. They wonder why they should bother about a few cases that turned out wrong. Well, those are the ones that matter most - such as the Russian market crash of 1998.

I would like scientists, engineers and the whole of society to understand the true meaning of statistics. People have generally been indoctrinated to believe that the world is simpler than it is. I'd like people to understand the difference between what I call mild randomness and wild randomness. Mild randomness is the thing that everyone thinks about where things go up and down a little bit in the financial market. Wild randomness is where one bad event in the stockmarket wipes out a long period of favourable events.

Se även
Benoit B. Mandelbrot
Den bok om finans/ekonomi man talar om i artikeln är The (Mis)Behaviour of Markets: A Fractal View of Risk, Ruin, and Reward (Amazonlänk).

Posted by hakank at 10:35 EM Posted to Diverse vetenskap

november 11, 2004

Senaste X

Några tidskrifter som legat i hyllan ett tag (virtuellt, alltså) och tyvärr fortsätter att ligga där.

KDnuggets News: 04:21

First Monday: November 2004.
Nästa månads tema är tydligen Gifting technologies, länken är till ett paper av Kevin McGee och Jörgen Skågeby:
File–sharing has become very popular in recent years, but for many this has become synonymous with file–getting. However, there is strong evidence to suggest that people have strong giving (or gifting) needs. This suggests an opportunity for the development of gifting technologies — and it also suggests an important research and challenge: what needs and concerns do gifters have and what technologies can be developed to help them? In this paper, we discuss the existing literature on gifting, report on an initial study of gifting in an online sharing community, and suggest some ways the study results can inform future research into gifting desires — as well as the design of specific gifting technologies.

JASSS (The Journal of Artificial Societies and Social Simulation): Volume 7 Issue 4.

Chance News: 13.05 (PDF).

NEP - New Economics Papers:
Experimental Economics: nep-exp-2004-11-07
Evolutionary Economics: nep-evo-2004-10-30

PCID ("Progress in Complexity, Information, and Design"): Volume 3.1, November 2004, utgiven av ISCID (International Society for Complexity, Information, and Design)

Uppdatering
Glömde ju:
Plus Magazine: Latest news samt latest issue. Beskrivning av tidskriften:
Plus is an internet magazine published five times a year which aims to introduce readers to the beauty and the practical applications of mathematics. Whether you want to know how to build a sundial, how to keep your messages safe or what shape the universe is, it's all here. So take a look at our latest issue, explore the archive and browse our careers library to see where maths can take you!

Posted by hakank at 05:59 EM Posted to Diverse vetenskap

oktober 15, 2004

Measuring beauty

Philip Ball i Nature:
Measuring beauty
Philip Ball asks whether a method of persuading people to tell the truth in subjective surveys might give us a more robust way to judge the quality of art.

Surveys to judge truth of answers
Predicting the results of political elections could be transformed from a black art into a science, thanks to a new way of getting people to tell the truth. According to the mathematical psychologist who devised it, his method can elicit more truthful subjective judgements about anything from business forecasts to the quality of a piece of art.

Posted by hakank at 10:47 EM Posted to Diverse vetenskap

oktober 13, 2004

1973--1974 Dictionary of the History of Ideas

Från Three-Toed Sloth: And Just Where Did You Get That Idea?

This is very cool, for a geeky intellectual value of cool: the 1973--1974 Dictionary of the History of Ideas is online. There's an immense amount of good stuff in there, from people who really knew what they were talking about.

Sedan följer en lista med en massa kända personer (med länkar)från diverse discipliner, t.ex. Kenneth Arrow, Isaiah Berlin, Mircea Eliade, Stu Kauffman, Oskar Morgenstern.

Posted by hakank at 06:49 EM Posted to Diverse vetenskap

The greatest equations ever

PhysicsWeb: The greatest equations ever:

Maxwell's equations of electromagnetism and the Euler equation top a poll to find the greatest equations of all time. Robert P Crease discusses the results of his reader survey.

Se även
The 20 greatest equations
The greatest equations ever (från maj 2004)
It Must Be Beautiful: Great Equations of Modern Science, Graham Farmelo (ed) (recension).

Via Language Log: Twenty greatest equations -- minus three?.

Posted by hakank at 06:39 EM Posted to Diverse vetenskap | Comments (1)

oktober 06, 2004

First Monday October 2004

First Monday, October 2004 innehåller bl.a. följande:

Bryn Loban:
Between rhizomes and trees: P2P information systems

The aim of the first part of this paper is to provide an overview of information retrieval in Peer–to–Peer (P2P) information systems in the file–sharing domain. Starting with a general overview of the concept of P2P information systems, the paper then focuses on five desktop–accessible P2P information systems: Napster with its clones OpenNap and eDonkey, and Gnutella and FastTrack (i.e., Kazaa). A detailed description is given of the attributes and properties of each P2P file–sharing information system, followed by an evaluation of the respective P2P file–sharing applications, taking each in turn and examining their respective strengths and weaknesses. This paper concludes with a critical comparative analysis and gives some suggestions for further investigation.

Paul Wouters, Iina Hellsten, and Loet Leydesdorff:
Internet time and the reliability of search engines
Search engines are unreliable tools for data collection for research that aims to reconstruct the historical record. This unreliability is not caused by sudden instabilities of search engines. On the contrary, their operational stability in systematically updating the Internet is the cause. We show how both Google and Altavista systematically relocate the time stamp of Web documents in their databases from the more distant past into the present and the very recent past. They also delete documents. We show how this erodes the quality of information. The search engines continuously reconstruct competing presents that also extend to their perspectives on the past. This has major consequences for the use of search engine results in scholarly research, but gives us a view on the various presents and pasts living side by side in the Internet.

Posted by hakank at 06:40 EM Posted to Diverse vetenskap

Digital Grusväg 2/2004 (den senaste, alltså)

Den senaste (2/2004, PDF) utgåvan av Digital Grusväg har kommit.

Från innehållsförteckningen (eventuella värdeomdömen i det nedenstående härstammar från den aktuella blogganteckningens författare och inte originalförfattaren):

• Motboken har avskaffats
  
• Tidskriftsnotis blev abrovinsch
  Kompletterande information från NE som beskriver abrovinsch sålunda:
  
abrovink´ el. abrovin´sch subst. ~en ~er
ORDLED: abro-vink-en, abro-vinsch-en
• kringgående rörelse [provins., vard.]: göra en ~
BET.NYANSER: a) ofta överfört, spec. med positiv innebörd (tillfällig) listig lösning: vi uppmuntrade honom i hans arbete genom diverse ~er som telefonvakt och flexibla klockslag för måltiderna b) spec. äv. negativt om ljusskygg affär, fiffel o.d. el. klumpigt, okontrollerat beteende e.d. c) allmännare konstig sak
HIST.: sedan 1965; sv. dial. abravink, abrovink; av ovisst urspr. men trol. besl. med sv. dial. aber, plur., 'rörelser av okynnig art'


• Häpnadsväckande rapport från vårt stenobservatorium
  
• Jordens undergång enligt Statistiska Centralbyrån
  En brilljant analys av när världen kommer att gå under.
  

Se ävenledes: Digital Grusväg, Digital Grusväg samt Digital Grusväg 1/2004

F.ö. är detta den första blogganteckningen å den nya datorn.

Posted by hakank at 06:16 EM Posted to Diverse vetenskap

augusti 29, 2004

Lekteori

I Theory of Play görs en genomgång av teorier kring lek/spel (eng. "play" alltså). Författare till texten är Matthew Didemus som google-tydligen är en musiker/filmmakare.

The concept of play is often overlooked and underestimated in philosophy. The following is a brief look at the idea of play in recent continental philosophy, its manifestation in the work of the Italian futurists, and its potential in electronic texts.

The following is an attempt to show the significance of play and to establish a working definition of the concept of play. In doing so we will examine three existing definitions of the concept play from that emerged in 20th century continental philosophy. Each of these three definitions belong to three respective theorists: 1) Huizinga, who attempts to map play’s presence and importance throughout the history of culture; 2) Gadamer, who drawing from Huizinga, attempts to define play in relation to the work of art; and finally 3) Derrida who attempts to link play to deconstruction.

Sista avsnittet handlar om spel/lek/skoj med elektroniska texter.

Electronics texts hold the potential to very playful for many reasons, but for our purposes we will be speaking of only two here: 1) They can operate separately from reality; and 2) They can and must be structured ground up, allowing them the potential to be structured in a playful manner. The first reason operates on several levels including: that they have there own time/space organization that is determined by the computer; and they are (in the sense that Gadamer speaks) always a (re)presentation of something. The second reason refers to the structures of computer programming. This means that all electronic texts are given rules within which they operate, but that these rules, because they are constructed ground up can either seek play or avoid it.

My project, which was created in conjunction with this paper, is an electronic text that was modeled after two rules established by Marinetti in several of the futurist manifestos.

Se Text Design Generator som skapar bilder liknande den som finns på första sidan i länken ovan.

Posted by hakank at 08:38 FM Posted to Diverse vetenskap

augusti 07, 2004

Senaste First Monday

Senaste First Monday innehåller bl.a. följande:

Joseph J. Esposito: The devil you don’t know: The unexpected future of Open Access publishing
Abstract
With the advent of the Internet and online publishing, the notion has arisen that access to the world’s research publications could be made available to one and all for free, presumably by shifting the costs to other places in the value chain and disintermediating publishers, a circumstance called Open Access (OA) publishing. While there are many hopes embedded in this view (lower costs, wider access, etc.), it appears more likely that Open Access will come about not through a revolution in the world of legacy publishing, but through upstart media built with the innate characteristics of the Internet in mind. An unanticipated outcome of this situation will be that the overall cost of research publications will rise, though the costs will be borne by different players, primarily authors and their proxies.

Brendan Luyt: Who benefits from the digital divide?
Abstract
New information and communication technologies are seen as a potent source of advancement for many countries in Africa, Asia and Latin America and have increasingly featured as topics of discussion in international fora. Who benefits from the rapid rise of this issue on the international agenda? This article argues that the promotion of the digital divide as a policy issue benefits four major groups: information capital, developing country governments, the development "industry," and global civil society.

Gary Hepburn: Seeking an educational commons: The promise of open source development models
Abstract
Schools are hindered by cost and flexibility problems as they try to obtain resources such as software and textbooks. Open source development processes are producing products that can address many of these problems and, as importantly, provide a better alignment with core educational values. Indeed, open source products potentially encourage the development of an educational commons.

Posted by hakank at 09:01 FM Posted to Diverse vetenskap