Mäkinen, Ville-Petteri, Forsblom, Carol, Thorn, Lena M, Wadén, Johan, Kaski, Kimmo, Ala-Korpela, Mika, ...
Background Cardiovascular disease is the main cause of premature death in patients with type 1 diabetes. Patients with diabetic kidney disease have an increased risk of heart attack or stroke....
Characterizing Motifs in Weighted Complex Networks (2008)
Jari Saramäki, Jukka-pekka Onnela, Janos Kertész, Kimmo Kaski
The local structure of unweighted complex networks can be characterized by the occurrence frequencies of subgraphs in the network. Frequently occurring subgraphs, motifs, have been related to the...
Heimo, Tapio, Kaski, Kimmo, Saramaki, Jari
We study the time dependence of maximal spanning trees and asset graphs based on correlation matrices of stock returns. In these networks the nodes represent companies and links are related to the...
A sequential algorithm for fast clique percolation (2008)
Kumpula, Jussi M., Kivela, Mikko, Kaski, Kimmo, Saramaki, Jari
In complex network research clique percolation, introduced by Palla et al., is a deterministic community detection method, which allows for overlapping communities and is purely based on local...
Toivonen, Riitta, Kovanen, Lauri, Kivelä, Mikko, Onnela, Jukka-Pekka, Saramäki, Jari, Kaski, Kimmo
This paper reviews, classifies and compares recent models for social networks that have mainly been published within the physics-oriented complex networks literature. The models fall into two...
Detecting modules in dense weighted networks with the Potts method (2008)
Heimo, Tapio, Kumpula, Jussi, Kaski, Kimmo, Saramaki, Jari
We address the problem of multiresolution module detection in dense weighted networks, where the modular structure is encoded in the weights rather than topology. We discuss a weighted version of the...
Vol. 00, No. 00, Month 200x, 1–15 Efficient data structures for sparse network representation (2008)
Jörkki Hyvönen, Jari Saramäki, Kimmo Kaski
Modern-day computers are characterized by a striking contrast between the processing power of the CPU and the latency of main memory accesses. If the data processed is both large compared to...
From ”binary ” networks to weighted networks (2008)
Jari Saramäki, Saram Ki, Jukka-pekka Jukka, Pekka Onnela, János Nos Kertész, Kert Sz, ...
• Complex networks: a way of looking at complex systems • Elements ⇒ nodes • Interactions ⇒ links • Interaction (or flow) strengths ⇒ link weights • E.g. traffic networks, social...
Name of the dissertation (2008)
Vibhor Kumar, Olli Yli-harja, Supervisor Prof, Kimmo Kaski, Instructor Dr, Jukka Heikkonen, ...
Teknillinen korkeakoulu Sähkö- ja tietoliikennetekniikan osasto Laskennallisen tekniikan laboratorio Distribution:
A Parallel Hardware Implementation (2007)
Timo Hämäläinen, Jukka Saarinen, Pekka Ojala, Kimmo Kaski
. This paper presents implementations of genetic algorithms in a tree shape parallel computer architecture. Different levels of parallelism involved in GAs are studied. In addition, basic models for...
Mikko Karttunen, Kimmo Kaski, Rafael A. Barrio, Limei Zhang
It is well known that simple reaction-diusion systems can display very rich pattern formation behaviour. Here we have studied two examples of such systems in three dimensions. First we investigate...
Using Document Features to Optimize Web Cache (2007)
Timo Koskela, Jukka Heikkonen, Kimmo Kaski
Abstract. In this paper Web cache optimization using document features is proposed. The problem in Web cache optimization is to decide which strategy to use in replacement of cache objects. While...
Spectral methods and cluster structure in correlation-based networks (2007)
Heimo, Tapio, Tibely, Gergely, Saramaki, Jari, Kaski, Kimmo, Kertesz, Janos
We investigate how in complex systems the eigenpairs of the matrices derived from the correlations of multichannel observations reflect the cluster structure of the underlying networks. For this we...
Vehtari, Aki, Mäkinen, Ville-Petteri, Soininen, Pasi, Ingman, Petri, Mäkelä, Sanna M, Savolainen, Markku J, ...
Abstract Background A key challenge in metabonomics is to uncover quantitative associations between multidimensional spectroscopic data and biochemical measures used for disease risk assessment and...
Spectral and network methods in the analysis of correlation matrices of stock returns (2007)
Heimo, Tapio, Saramaki, Jari, Onnela, Jukka-Pekka, Kaski, Kimmo
Correlation matrices inferred from stock return time series contain information on the behaviour of the market, especially on clusters of highly correlating stocks. Here we study a subset of New York...
Analysis of a large-scale weighted network of one-to-one human communication (2007)
Onnela, Jukka-Pekka, Saramaki, Jari, Hyvonen, Jorkki, Szabo, Gabor, De Menezes, M. Argollo, Kaski, Kimmo, ...
We construct a connected network of 3.9 million nodes from mobile phone call records, which can be regarded as a proxy for the underlying human communication network at the societal level. We assign...
Emergence of self-sustained patterns in small-world excitable media (2007)
Sinha, Sitabhra, Saramaki, Jari, Kaski, Kimmo
Motivated by recent observations that long-range connections (LRC) play a role in various brain phenomena, we have observed two distinct dynamical transitions in the activity of excitable media where...
Jukka-pekka Onnela, Jari Saramäki, Jörkki Hyvönen, Gábor Szabó, Kimmo Kaski, ...
open–access journal for physics
Limited resolution in complex network community detection with Potts model approach (2006)
Kumpula, Jussi M., Saramaki, Jari, Kaski, Kimmo, Kertesz, Janos
According to Fortunato and Barthelemy, modularity-based community detection algorithms have a resolution threshold such that small communities in a large network are invisible. Here we generalize...
Turing systems as models of complex pattern formation (2006)
Teemu Leppänen, Mikko Karttunen, Kimmo Kaski, R. A. Barrio
Turing systems as models of complex pattern formation
Self-Organising Map Approach to Individual Profiles: Age, Sex and Culture in Internet Dating (2006)
Suna, Teemu, Hardey, Michael, Huhtinen, Jouni, Hiltunen, Yrjö, Kaski, Kimmo, Heikkonen, Jukka, ...
A marked feature of recent developments in the networked society has been the growth in the number of people making use of Internet dating services. These services involve the accumulation of large...
Kinetic theory models for the distribution of wealth: power law from overlap of exponentials (2005)
Patriarca, Marco, Chakraborti, Anirban, Kaski, Kimmo, Germano, Guido
Various multi-agent models of wealth distributions defined by microscopic laws regulating the trades, with or without a saving criterion, are reviewed. We discuss and clarify the equilibrium...
Spatial snowdrift game with myopic agents (2004)
Sysi-Aho, Marko, Saramaki, Jari, Kertesz, Janos, Kaski, Kimmo
We have studied a spatially extended snowdrift game, in which the players are located on the sites of two-dimensional square lattices and repeatedly have to choose one of the two strategies, either...
Turing systems as models of complex pattern formation (2004)
Leppänen,Teemu, Karttunen,Mikko, Barrio,R.A., Kaski,Kimmo
Half a century ago a reaction-diffusion system of two chemicals was introduced by Alan Turing to account for morphogenesis, i.e., the development of patterns, shapes and structures found in nature....
Scale-Free Networks Generated By Random Walkers (2004)
We present a simple mechanism for generating undirected scale-free networks using random walkers, where the network growth is determined by choosing parent vertices by sequential random walks. We...
Invisible Hand Effect in an Evolutionary Minority Game Model (2004)
Sysi-Aho, Marko, Saramaki, Jari, Kaski, Kimmo
In this paper we study the properties of a Minority Game with evolution realized by using genetic crossover to modify fixed-length decision-making strategies of agents. Although the agents in this...
A statistical model with a standard Gamma distribution (2004)
Patriarca, Marco, Chakraborti, Anirban, Kaski, Kimmo
We study a statistical model consisting of $N$ basic units which interact with each other by exchanging a physical entity, according to a given microscopic random law, depending on a parameter...
Physica A, Marko Sysi-aho, Jari Sarama Ki, Kimmo Kaski
Invisible hand effect in an evolutionary minority game model
Gibbs versus non-Gibbs distributions in money dynamics (2003)
Patriarca, Marco, Chakraborti, Anirban, Kaski, Kimmo
We review a simple model of closed economy, where the economic agents make money transactions and a saving criterion is present. We observe the Gibbs distribution for zero saving propensity, and...
Dimensionality effects in Turing pattern formation (2003)
Leppanen, Teemu, Karttunen, Mikko, Kaski, Kimmo, Barrio, Rafael A.
The problem of morphogenesis and Turing instability are revisited from the point of view of dimensionality effects. First the linear analysis of a generic Turing model is elaborated to the case of...
Searching good strategies in adaptive minority games (2003)
Sysi-Aho, Marko, Chakraborti, Anirban, Kaski, Kimmo
In this paper we introduce adaptation mechanism based on genetic algorithms in minority games. If agents find their performances too low, they modify their strategies in hope to improve their...
Biology helps you to win a game (2003)
Sysi-Aho, Marko, Chakraborti, Anirban, Kaski, Kimmo
We present a game of interacting agents which mimics the complex dynamics found in many natural and social systems. These agents modify their strategies periodically, depending on their performances...
Connectivity of Turing structures (2003)
Leppanen, Teemu, Karttunen, Mikko, Barrio, R. A., Kaski, Kimmo
It is well-known that in two dimensions Turing systems produce spots, stripes and labyrinthine patterns, and in three dimensions lamellar and spherical structures or their combinations are observed....
Turing Systems as Models of Complex Pattern Formation (2003)
Mikko Karttunen, R. A. Barrio, Kimmo Kaski
Half a century ago a reaction-diffusion system of two chemicals was introduced by Alan Turing to account for morphogenesis, i.e., the development of patterns, shapes and structures found in nature....
A new dimension to Turing patterns (2002)
Leppanen, Teemu, Karttunen, Mikko, Kaski, Kimmo, Barrio, Rafael A., Zhang, Limei
It is well known that simple reaction-diffusion systems can display very rich pattern formation behavior. Here we have studied two examples of such systems in three dimensions. First we investigate...
Adaptation using hybridized genetic crossover strategies (2002)
Sysi-Aho, Marko, Chakraborti, Anirban, Kaski, Kimmo
We present a simple game which mimics the complex dynamics found in most natural and social systems. Intelligent players modify their strategies periodically, depending on their performances. We...
Intelligent Minority Game with genetic-crossover strategies (2002)
Sysi-Aho, Marko, Chakraborti, Anirban, Kaski, Kimmo
We develop a game theoretical model of $N$ heterogeneous interacting agents called the intelligent minority game. The ``intelligent'' agents play the basic minority game and depending on their...
Crystalline-Amorphous Interface: Molecular Dynamics Simulation of Thermal Conductivity (2002)
Alfthan, Sebastian Von, Kuronen, Antti, Kaski, Kimmo
Effect of a crystalline-amorphous interface on heat conduction has been studied using atomistic simulations of a silicon system. System with amorphous silicon was created using the bond-switching...
Random spreading phenomena in annealed small world networks (2001)
Lahtinen, Jani, Kertész, János, Kaski, Kimmo
We study the simple random walk dynamics on an annealed version of a Small-World Network (SWN) consisting of $N$ nodes. This is done by calculating the mean number of distinct sites visited S(n) and...
Scaling of random spreading in small world networks (2001)
Lahtinen, Jani, Kertész, János, Kaski, Kimmo
In this study we have carried out computer simulations of random walks on Watts-Strogatz-type small world networks and measured the mean number of visited sites and the return probabilities. These...
Recurrent SOM with Local Linear Models in Time Series Prediction (1998)
Timo Koskela, Markus Varsta, Jukka Heikkonen, Kimmo Kaski
Recurrent Self-Organizing Map (RSOM) is studied in three different time series prediction cases. RSOM is used to cluster the series into local data sets, for which corresponding local linear models...
Temporal Sequence Processing using Recurrent SOM (1998)
Timo Koskela, Markus Varsta, Jukka Heikkonen, Kimmo Kaski
Recurrent Self-Organizing Map (RSOM) is studied in temporal sequence processing. RSOM includes a recurrent difference vector in each unit of the map, which allows storing temporal context from...
Temporal Sequence Processing using Recurrent SOM (1998)
Timo Koskela, Markus Varsta, Jukka Heikkonen, Kimmo Kaski
Recurrent Self-Organizing Map (RSOM) is studied in temporal sequence processing. RSOM includes a recurrent difference vector in each unit of the map, which allows storing temporal context from...
Ari Lukkarinen, Ari Lukkarinen, Kimmo Kaski, Kimmo Kaski
Mechanical properties of electrorheological fluids under various dynamical loading conditions have been studied using a computer simulation model. The model assumes electrostatic point-dipole...
Recurrent SOM with local linear models in time series prediction (1998)
Timo Koskela, Markus Varsta, Jukka Heikkonen, Kimmo Kaski
Recurrent Self-Organizing Map (RSOM) is studied in three di erent time series prediction cases. RSOM is used to cluster the series into local data sets, for which corresponding local linear models...
Time Series Prediction Using Recurrent SOM with Local Linear Models (1997)
Otaniemi B, Timo Koskela, Timo Koskela, Markus Varsta, Markus Varsta, Jukka Heikkonen, ...
A newly proposed Recurrent Self-Organizing Map (RSOM) is studied in time series prediction. In this approach RSOM is used to cluster the data to local data sets and local linear models corresponding...
Time Series Prediction Using Recurrent SOM with Local Linear Models (1997)
Timo Koskela, Markus Varsta, Jukka Heikkonen, Kimmo Kaski
A newly proposed Recurrent Self-Organizing Map (RSOM) is studied in time series prediction. In this approach RSOM is used to cluster the data to local data sets and local linear models corresponding...
Time Series Prediction with Multilayer Perceptron, FIR and Elman Neural Networks (1996)
Timo Koskela, Mikko Lehtokangas, Jukka Saarinen, Kimmo Kaski
Multilayer perceptron network (MLP), FIR neural network and Elman neural network were compared in four different time series prediction tasks. Time series include load in an electric network series,...
Vehtari, Aki, Mäkinen, Ville-Petteri, Soininen, Pasi, Ingman, Petri, Mäkelä, Sanna M, Savolainen, Markku J, ...
1H NMR metabonomics approach to the disease continuum of diabetic complications and premature death
Mäkinen, Ville-Petteri, Soininen, Pasi, Forsblom, Carol, Parkkonen, Maija, Ingman, Petri, Kaski, Kimmo, ...
Subtle metabolic changes precede and accompany chronic vascular complications, which are the primary causes of premature death in diabetes. To obtain a multimetabolite characterization of these...
Self-Organising Map Approach to Individual Profiles: Age, Sex and Culture in Internet Dating
Teemu Suna, Michael Hardey, Jouni Huhtinen, Yrjö Hiltunen, Kimmo Kaski, Jukka Heikkonen, ...
A marked feature of recent developments in the networked society has been the growth in the number of people making use of Internet dating services. These services involve the accumulation of large...
Mäkinen, Ville-Petteri, Forsblom, Carol, Thorn, Lena M., Wadén, Johan, Gordin, Daniel, Heikkilä, Outi, ...
OBJECTIVE—Poor glycemic control, elevated triglycerides, and albuminuria are associated with vascular complications in diabetes. However, few studies have investigated combined associations between...
Gibbs versus non-Gibbs distributions in money dynamics
Marco Patriarca, Anirban Chakraborti, Kimmo Kaski
We review a simple model of closed economy, where the economic agents make money transactions and a saving criterion is present. We observe the Gibbs distribution for zero saving propensity, and...
Kinetic theory models for the distribution of wealth: power law from overlap of exponentials
Marco Patriarca, Anirban Chakraborti, Kimmo Kaski, Guido Germano
Various multi-agent models of wealth distributions defined by microscopic laws regulating the trades, with or without a saving criterion, are reviewed. We discuss and clarify the equilibrium...