mi facki lei cinri zasti

STOC Papers

2012-02-14T06:57:00.000-08:00

A blog post with links to the accepted STOC 2010 papers. Quite some intesting topics!

Architecture: Hedonistic sustainability

2012-01-28T12:18:00.000-08:00

I've been only twice to Copenhagen, but I really liked it there. That's of course because the Danish people are very nice, but also because I really like how the city feels.
There's a great TEDtalk on architecture by some Danish with focus on sustainability: Link to TED page.

I strongly suggest to not watch the video in the embedded video frame size!

Market Makers & Prediction Markets

2012-01-27T16:53:00.000-08:00

A while ago I posted on the idea of futarchy and followed up with a post on implementation and issues of virtual stock markets.

I only posted links on auction markets, i.e. where one party makes an offer, another one a request and the system finds a match. That only works good for systems with high liquidity. Especially on prediction markets with combinatorical outcomes (e.g. of the form "if person A becomes the candidate for party 1, then party 2 will win the election" or even more complex constructions) this is difficult: you need to find people making similar opposite bets to match. A way around of this is to use a market maker instead of an auctioneer. It takes the trades directly instead of leading a negotiation between to parties. The price is set automatically by the system. This, of course, also has drawbacks. In a real life system, the market maker provides liquidity and thus is at risk losing some money. Moreover, the pricing of the goods depends on parameters of the market maker. Wrong values for thick or thin (i.e. markets with many/few participants) might make the price either bounce up and down or move only tiny bits.

Uncertainity Principle(s)

2012-01-07T05:37:00.000-08:00

Most people know a formulation of the uncertainity principle in quantum mechanics (by Heisenberg), where it basically gives a bound (in terms of the standard deviations of ~) for simultaneous measurements of complementary properties (i.e. measurement operators with non-negative commutator).

There are a number of other places where the principce turns up. It comes from an application of the cauchy schwarz inequality to the fourier transformation. Here's a set of (german) slides from a lecture. Recently Terry Tao posted on a a formulation of the principle due to Mongomery, which has applications in analytic number theory.

On Human Brain Size; the Conciousness and Anaesthesia

2012-01-03T17:28:00.000-08:00

A happy new year to all readers. I just got two articles with some references on further resources:

In near future, I will post some more math; I just haven't read all the things I stumbled on.

edit: let me squeeze in another link to an article:

Language learning is fast when words are connected with movements/gestures, which is also true for abstract words with no obvious gesture for it.

On (implementation issues of) Virtual Stock Markets

2011-12-24T06:29:00.000-08:00

After my recent post on prediction markets, I decided to implement a small auctioneer for virtual stock markets with two parties making deals, i.e. not a market maker mechanism but a (traditional) double auction. But, despite the simple idea behind a bid/ask driven market, the implementation has to take into account quite a number of details: can you buy/sell one unit or multiple units of a good at a time? Does trading occur at discrete events or is it continuous? Is pricing uniform (all trade at the same equilibirum price) or discriminatory (individual matching of bid/ask orders)? And, if one the two options is chosen, how is the price determined?

Beside the double auction system, bidding can take other forms: Auctions and Bidding: A Guide for Computer Scientists
Everything you wanted to know about double auctions, but were afraid to (bid or) ask
And finally a paper on two multi unit k-double auction algorithms

Reading Speed: Chinese vs English

2011-12-22T08:26:00.000-08:00

I always wondered about mankind's languages and writing systems, one of the reasons I looked into Lojban (quite) a while ago. In an earlier post about writing systems I expressed my fascination about non-linear systems. But even with linear systems, we have alphabetic, syllabic and logographic systems. But it turns out the our systems are optimal in the sense that our cognitive abilities won't let us process more optimized systems, at least that is indicated by a study on reading speed with Chinese vs English - two major examples of logographic and alphabetic writing systems.

Futarchy: applying prediction markets

2011-12-14T08:34:00.000-08:00

R. Hanson suggests to use prediction markets to make better use of information to evaluate strategies in politics. He calls the combination of democracy and speculative market information processing futarchy. There is a short manifesto and a full paper (PDF).

The central idea is: Use democracy to express what you want, use prediction markets to evaluate how to reach these goals. People can give strategies which are traded after paying a small fee; when they seem to be efficient the get a payback, otherwise they loose the fee. Thus good strategies are rewarded, bad ones are not rewarded but cost an extra fee. Augmented GDP and other indicators give a measured value to the state of the country.

Physics: Faster-Than-Light Signals and Special Relativity; popular science articles by Ashtekar

2011-12-13T07:01:00.000-08:00

Two things to link: The frenzy about findings and non-findings at the LHC pose a good reason to think about the possible implications. Therefore, an article by R.Geroch on the consistency of faster than light signals (e.g. neutrinos measured at the LHC) and special relativity (for example, due to partially breaking Lorentz invariance for neutrinos, but not all the other particles). There is also a blog post on FTL-neutrinos.

Moreover there is a bunch of popular science articles by A.Ashtekar (who is one of the founders of loop quantum gravity).

Resources on Prediction Markets

2011-12-12T16:51:00.000-08:00

Prediction Markets might be useful in modern politics - gathering crowd information (expected outcomes) and filtering experts from the crowd (i.e. successful traders in the market).

Just a bunch of links to read on the matter:

Prediction Markets im Journal of Economic Perspectives.
Combinatorial Prediction Markets at oddhead blog. Overview about types of combinatorial markets and the problems with handling them
Betting on Ideas in Communications of the ACM
Internet-Based Virtual Stock Markets for Business Forecasting

CSR Rating Agencies: What is Their Global Impact?

2011-12-08T11:22:00.000-08:00

At SpringerLink's JOURNAL OF BUSINESS ETHICS you'll find an interesting article on CSR Rating Agencies: What is Their Global Impact?

Epigenetic Effects of Tobacco: Increased sensitivity for drug addiction

2011-12-07T10:19:00.000-08:00

A continuously updated blog post on the effects of tobacco and modern additives to human brain/bodies.

I really don't understand why there isn't a huge debate about a reevaluation of all drugs under the guidelines of modern drug research instead of this "legalize everything" debate. Stuff like Krokodil (see some effects after usage, even once or a few times at the google image search but be advised: very graphic ..) just isn't anything you should offer to try even under the assumption that people are behaving rational.

Nuclear Energy: Thorium Reactors

2011-11-27T11:56:00.000-08:00

I recently discovered a small gap in my education in nuclear energy. It concerns LFTR reactors. They seem to be reconsidered after uranium based reactors were favored after world war 2 and the during the cold war due to their dual use in energy production as well as the generation of byproducs for nuclear weapons.

There are several videos on the google tech talk channlel, just two of those:

Contemporary Physics

2011-11-18T12:31:00.000-08:00

Just some physics stuff from recent news: An article at wired about recent findings at lhc/cern regarding the charge party violation and a confirmation about the (too) fast neurino measurements at the lhc.

Machine Learning (lecture) Videos

2011-11-15T10:19:00.000-08:00

I haven't watched them all yet, but since I have only little background in machine learning, I find this to be highly enjoyable: Link to Machine Learning Videos. The videos were taking during a summer school: Link to the Summer School Website

CogSci: The Role of Dreams in Great Discoveries

2011-11-11T14:52:00.000-08:00

An article from scientific american about an "alternative state of consciousness" we enter when dreaming, allowing us to tackle problems we cannot understand consciously

CogSci: A Map of the Brain

2011-11-10T14:57:00.000-08:00

Just a quick link to a short TED talk.

Patent wars

2011-11-07T15:28:00.000-08:00

A recent interview with a google lawyer on the patent system.

And I added another link to the last post on CogSci...

CogSci: Embodied Cognition and Consciousness

2011-11-05T17:33:00.000-07:00

Arguing against a Descartian dualism and for a interconnection between brain and body, the article at scientific american blogs gives nice pointers and references for an embodiment point of view of cognition. It's interesting to see if there is some "mind" kind of core in the biomachine that the human being actually is. The normal bio-chemic interconnection between mind and body seems to be quite natural as the mind needs the body to survive (and stay healthy) in order to do so itself.

At the thoughts on thoughts blog you'll find a 3 part post on the possible functions of consciousness which is an interesting topic to think about, especially keeping in mind the aforementioned article:

[edit] Slightly related, there is another article on the work our subconscious does for us at the discovery magazine. [/edit]

Some Commentaries on Politics

2011-10-11T07:43:00.000-07:00

Project Syndicate features some interesting articles and commentaries about politics.

Project Syndicate: the world's pre-eminent source of original op-ed commentaries. A unique collaboration of distinguished opinion makers from every corner of the globe, Project Syndicate provides incisive perspectives on our changing world by those who are shaping its politics, economics, science, and culture. Exclusive, trenchant, unparalleled in scope and depth: Project Syndicate is truly A World of Ideas.

It includes authors like Ban Ki-moon, Christine Lagarde, Javier Solana, Dominique Strauss-Kahn, Martin Feldstein, Otmar Issing, Peter Singer and many more.

On the (Un-)Reality of Mathematics

2011-10-10T16:59:00.000-07:00

I stumbled upon a paper by Barry Mazur titled "Mathematical Platonism and its Opposites" which points out a few things to keep in mind when thinking about the question: Is mathematics discovered or invented?

Updates

2011-10-10T16:58:00.000-07:00

During the last 15 months, I discovered quite some interesting things....unfortunately I didn't post anything. Some of those discoveries will be posted here in near future.

Lego chess and caffeine

2010-07-21T06:12:00.000-07:00

Some links for fun:

Complexity Theory related surveys

2010-07-19T06:41:00.000-07:00

Some complexity related survey-ish papers:
A CACM article from September 2009 titled "The status of the P versus NP problem" available here.

Mentioned in the above survey, two more interesting papers:

an article by Scott Aaronson on the independence of the P vs. NP question
a paper by Impagliazzo giving a personal view on the average case complexity

I did not have enough time to read more of the cited works in the CACM article, but I'll add more as I have time to read it.

Coalgebraic Logic

2010-07-06T01:51:00.000-07:00

Due to recent needs, I looked up some stuff on coalgebraic logic, a generalization of modal logics. If you're unfimiliar with the notion of coalgebras, read the good 'tutorial on coalgebras and coinduction' by Jacobs and Rutten.
I keep extending this post to contain a small collection of useful reading material, staring with this list:

Moss - Coalgebraic Logic

For modal logics per se, have a look at the handbook of modal logics.