Friday, 23 December 2011

Crowd dynamics : Fluid Dynamics to Statistical Physics

Study of crowd dynamics with techniques imported from Physical
sciences, particularly statistical physics, is not very new idea but
relatively young field. (See economist article). A recent article gives a
recent advances in crowd dynamics in analogy with hydrodynamics,
Visual crowd surveillance through a hydrodynamics lens.

Tuesday, 13 December 2011

Monday, 12 December 2011

Dennis Ritchie (1941--2011)

In memory of Dennis Ritchie: article

Analysis of MPI codes.

Massage passing interface library, since its inception is on the rise constantly in parallel programming community. This recent article discusses the analysis of MPI based codes.

Sunday, 11 December 2011

High Performance Fortran

High performance fortran
Fortran is truly a language of choice in most of the scientific applications and
one of the pioneering in high performance computing. This recent article discusses current status.

ocaml for the masses

Ocaml for the masses
Story about how a functional language is used in financial industry.

Chaotic Storms

Modeling chaotic storms appears to be a challenge due to unpredictable nature of the weather patterns.

Sunday, 27 November 2011

Biologically Inspired Algorithms for Financial Modelling

Biologically inspired algorithms (BIA) has a special place in heuristic modeling in many different fields of computational sciences, for example in materials simulations, AI, operational research among many others. A recent book covers the area of Financial Modeling using BIAs. Chapters about corporate failure prediction using grammatical evolution and ant colony are quite interesting. I think topic of failure prediction is closely related to resilience of a financial institution, see my earlier blog entry.

Sunday, 23 October 2011

n x n games: The stochastic linking dynamics

Interesting generalization of the stochastic linking dynamics is proposed by a Chinese team.
[article], base on [article].

Similation of rare-events review

A recent review on rare event similation both from stochastic and Hamiltonian dynamics point of view is presented by French group [ article ].

Fokker-Planck Equation with logarithmic potential

Israeli group recently shown exact solution of Fokker-Planck equation with 1D logarithmic potential [ article ]. Group explicitly construct probability density function of diffusing particle in a potential, a ln x, a >0.

Thursday, 15 September 2011

Solving Linear Systems Fast: A Breakthrough in Algorithm Design

A recent algorithm solves diagonally dominant systems faster than any existing algorithm. Work of CMU scientist revealed. [popular article].

Sunday, 7 August 2011

Resiliance Financial Networks

A counter intuitive conclusion is given recently on increasing connectivity of financial institutions would increase the risk of collapse. A paper by Italian-US team explains why [pdf] [link].

Saturday, 9 July 2011

Langevin Bridges

A recent work in determining transition pathways using overdamped Langevin dynamics is proposed [link]. Generating transition paths by Langevin bridges approximates the Fokker-Planck equation for short times.

Sunday, 8 May 2011

Thesis on complex networks

A recent thesis by Jan Scholz of Frankfurt University has addressed topological characteristics of complex networks. Apart from the original results presented in the later chapters, thesis contains well written account of complex networks research from graph and game theory perspective.

Sunday, 20 March 2011

Sunday, 13 March 2011

Universal Intelligence

Turing test is maybe the core concept of artificial intelligence. A recent work that claims to extent context of Turing test is titled:Measuring universal intelligence: Towards an anytime intelligence test. The primary contribution of this research by Oralloa and Doweb is centred around the applicability of the Turing test to any type of intelligence via employing Kolmogorov complexity .

Saturday, 5 March 2011

Coarse grained Molecular Modelling and Information Loss

Tracking atomistic details in molecular simulations generates a lot of data and reveals a lot of statistical and thermodynamic properties of system under study. Due to large system sizes and time scales in a realistic molecular system, current atomistic simulations needs to cover up to 10-12 orders of magnitude computation time or system size compare to what current computers can tackle. A coarser representation of molecular system is usually employed to reduce the spatial and time scales, proportionally computation time. Fine details of the system is removed and
effective interactions or physical characteristics are introduced instead.(See a review by Pep Espanol Statistical Mechanics of Coarse Graining).

An important problem of information loss in this coarse graining procedure is recently investigated by using relative entropy approach, where entropy of reduce system compared to detailed system by a group in California [link].

A similar effort in this direction to model water (see my short blog as well [link])
is developed by Van gunsteren group coarse graining polarizable water [link].

Friday, 25 February 2011

Quantum mechanical Szilard engine

A recent article on the analysis of Quantum Szilard Engine (QSZE) has appeared [link]. Japanese team derived an explicit analytical expression for work done by arbitrary number of molecules.

Wednesday, 2 February 2011

Community Detection Review

A recent detailed review on Community detection is appeared in Physics Reports [link].

Community Detection with node removal: Open source software codes

A novel approach to community detection in network is proposed by UC Davis lead research [link]. Team improve the detection of communities by removing nodes that may disturb the structure/community. hey applied this algorithm in open source software development projects like Apache, Perl development time series and biological networks.

Saturday, 29 January 2011

Need of physics in cell biology

Physics and cell biology used to be very distinct fields, but now a days, more and more theoretical physics oriented work force moved to this domain and life sciences, specially from statistical mechanics and complex systems point of view, and even people from string theory! A recent article that reviews this perspective appeared [link].
In the similar lines in the article [link] discussion on physics role in biology in generic terms explored. In a humorous way current funding policies are summarized : "all science is either biology or tool-making for biology or not fundable".

Tuesday, 25 January 2011

Random Walk in Confined Diffusion

A recent work explores a theory of random walk in Confined environment [link].

Equivalence of replica and cavity methods

Replica and cavity methods appear [link] in tackling problems with spin glasses and related optimization. A recent work shown the equivalence of these two methods in the context of random networks [link].

Stochastic blockmodels: Graph representations and Community Detection

Partitioning a graph and its efficient representation appear to have an increasing importance, due to its implications in complex networks i.e. social networks. One important model that is utilized is called Stochastic blockmodels [link] where attributes of connections generates certain classification (blocks) that leads to a reduced representation or inherent partions. A recent work by Newman generalizes this model to real networks to detect communities [link], by taking into account the variation in the vertex degree.

Thursday, 20 January 2011

Minimizing Polynomial Functions

A recent work appear on arXiv [link] introduced a method to globally minimize multivariate polynomials which bridges mathematical programming and algebraic geometry. There is a popular article on this [link].

Tuesday, 18 January 2011

Sampling in rare events under non-equilibrium conditions

In a recent work, reported by Berryman-Schilling proposes a novel method for calculating the time-series of the probability of a rare event in non-equilibrium conditions [link]. The main contribution of this work lies in the modification of  Pruned-enriched Rosenbluth method, where they call this new algorithm S-PRES. This work might be an interesting  advancement while it does not assume a prior knowledge on the transition paths itself.

Friday, 7 January 2011

Optimal random search

A recent work shows how to exploit a priori distribution in random search.It is shown that square of the distribution must be selected as a search distribution [pre][arxiv].
(c) Copyright 2008-2015 Mehmet Suzen (suzen at acm dot org)

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