Dietrich Stauffer

Inhomogeneous and self-organised temperature in Schelling-Ising model (2007)

When a region is conquered by people speaking another language, we assume within the Schulze model that at each iteration each person with probability s shifts to the conquering language. The time...

Muller, Katharina, Schulze, Christian, Stauffer, Dietrich

The Schelling model of 1971 is a complicated version of a square-lattice Ising model at zero temperature, to explain urban segregation, based on the neighbour preferences of the residents, without...

Do language change rates depend on population size? (2007)

Wichmann, Soeren, Stauffer, Dietrich, Schulze, Christian, Holman, Eric W.

An earlier study (Nettle 1999b) concluded, based on computer simulations and some inferences from empirical data, that languages will change the more slowly the larger the population gets. We...

Superdiffusion in a Model for Diffusion in a Molecularly Crowded Environment (2007)

Stauffer, Dietrich, Schulze, Christian, Heermann, Dieter W.

We present a model for diffusion in a molecularly crowded environment. The model consists of random barriers in percolation network. Random walks in the presence of slowly moving barriers show normal...

Monte Carlo Simulation of Age-Dependent Host-Parasite Relations (2007)

Stauffer, Dietrich, Proykova, Ana, Lampe, Karl-Heinz

The death of a biological population is an extreme event which we investigate here for a host-parasitoid system. Our simulations using the Penna ageing model show how biological evolution can...

Monte Carlo Simulation of Medical Resource Allocation (2007)

Proykova, Ana, Stauffer, Dietrich

Computer simulations prove that we should spend more money on red wine than on medication. We optimise the problem of how to distribute a fixed amount of money between medication and food spendings,...

Competition of languages in the presence of a barrier (2007)

On the relation between structural diversity and geographical distance among languages: Observations and computer simulations (2007)

Using the Schulze model for Monte Carlo simulations of language competition, we include a barrier between the top half and the bottom half of the lattice. We check under which conditions two...

Holman, Eric W., Schulze, Christian, Stauffer, Dietrich, Wichmann, Søren

"Antiferromagnetism" in social relations and Bonabeau model (2006)

Search for bottleneck effects in Penna ageing and Schulze language model (2006)

We here present a fixed agents version of an original model of the emergence of hierarchies among social agents first introduced by Bonabeau \textit{et al}. Having interactions occurring on a social...

Malarz, Krzysztof, Stauffer, Dietrich

No influence was seen when in two models with memory effects the populations were drastically decreased after equilibrium was established, and then allowed to increase again.

Phase transition in Nowak-Sznajd opinion dynamics (2006)

Woloszyn, Maciej, Stauffer, Dietrich, Kulakowski, Krzysztof

The Nowak modification of the Sznajd opinion dynamics model on the square lattice assumes that with probabilities beta and gamma the opinions flip due to mass-media advertising from down to up, and...

On the relation between structural diversity and geographical distance among languages: observations and computer simulations (2006)

Holman, Eric W., Schulze, Christian, Stauffer, Dietrich, Wichmann, Soren

The recent availability of larger typological databases such as Haspelmath et al. (2005) has brought the linguistics community closer to having a solid, empirical foundation for making actual claims...

The Impact of External Events on the Emergence of Social Herding of Economic Sentiment (2006)

Hohnisch, Martin, Stauffer, Dietrich, Pittnauer, Sabine

We investigate the impact of an exogenous environment on the emergence of social herding of economic sentiment. An interactions-driven dynamics of economic sentiment is modeled by an Ising model on a...

Why are diploid genomes widespread and dominant mutations rare? (2006)

Garncarz, Diana, Cebrat, Stanislaw, Stauffer, Dietrich, Blindert, Klaus

We have used the sexual Penna ageing model to show that the relation between dominance and recessiveness could be a force which optimizes the genome size. While the possibility of complementation of...

Monte Carlo simulation of survival for minority languages (2006)

Modelling linguistic taxonomic dynamics (2006)

Our earlier language model is modified to allow for the survival of a minority language without higher status, just because of the pride of its speakers in their linguistic identity. An appendix...

Wichmann, Soren, Stauffer, Dietrich, Lima, F. Welington S., Schulze, Christian

This paper presents the results of the application of a bit-string model of languages (Schulze and Stauffer 2005) to problems of taxonomic patterns. The questions addressed include the following: (1)...

Computer simulation of language competition by physicists (2006)

Power Laws and Gaussians for Stock Market Fluctuations (2006)

Computer simulation of languages is an old subject, but since the paper of Abrams and Strogatz (2003) several physics groups independently took up this field. We shortly review their work and bring...

Tuncay, Caglar, Stauffer, Dietrich

The daily volume of transaction on the New York Stock Exchange and its day-to-day fluctuations are analysed with respect to power-law tails as well long-term trends. We also model the transition to a...

Microscopic Abrams-Strogatz model of language competition (2006)

Stauffer, Dietrich, Castello, Xavier, Eguiluz, Victor M., Miguel, Maxi San

The differential equations of Abrams and Strogatz for the competition between two languages are compared with agent-based Monte Carlo simulations for fully connected networks as well as for lattices...

Simulation of language competition by physicists (2005)

Computer simulations for biological aging and sexual reproduction (2005)

Following Abrams and Strogatz 2003 and Patriarca and Leppanen 2004, five other physics groups independently started to simulate the competition of languages, as opposed to the evolution of a human...

Dietrich Stauffer

Computer simulations for biological aging and sexual reproduction

Adjustment and social choice (2005)

Simulation of Rapoport's rule for latitudinal species spread (2005)

We discuss the influence of information contagion on the dynamics of choices in social networks of heterogeneous buyers. Starting from an inhomogeneous cellular automata model of buyers dynamics, we...

Stauffer, Dietrich, Rohde, Klaus

Rapoport's rule claims that latitudinal ranges of plant and animal species are generally smaller at low than at high latitudes. However, doubts as to the generality of the rule have been expressed,...

Does telomere elongation lead to a longer lifespan if cancer is considered? (2005)

Masa, Michael, Cebrat, Stanislaw, Stauffer, Dietrich

As cell proliferation is limited due to the loss of telomere repeats in DNA of normal somatic cells during division, telomere attrition can possibly play an important role in determining the maximum...

Diffusion in scale-free networks with annealed disorder (2005)

Stauffer, Dietrich, Sahimi, Muhammad

The scale-free (SF) networks that have been studied so far contained quenched disorder generated by random dilution which does not vary with the time. In practice, if a SF network is to represent,...

Can a few fanatics influence the opinion of a large segment of a society? (2005)

Stauffer, Dietrich, Sahimi, Muhammad

Models that provide insight into how extreme positions regarding any social phenomenon may spread in a society or at the global scale are of great current interest. A realistic model must account for...

Discrete Simulation of the Dynamics of Opinions about Extremism (2005)

Stauffer, Dietrich, Sahimi, Muhammad

We propose a discrete model for how opinion about a given phenomenon, about which various groups of a population have different degrees of enthusiasm, such as fanaticism and extreme social and...

Simulation of geographical trends in Chowdhury ecosystem model (2005)

Rohde, Klaus, Stauffer, Dietrich

A computer simulation based on individual births and deaths gives a biodiversity increasing from cold to warm climates, in agreement with reality. Complexity of foodwebs increases with time and at a...

Evolutionary ecology in-silico: Does mathematical modelling help in understanding the "generic" trends? (2005)

Sociophysics Simulations IV: Hierarchies of Bonabeau et al (2005)

Motivated by the results of recent laboratory experiments (Yoshida et al. Nature, 424, 303-306 (2003)) as well as many earlier field observations that evolutionary changes can take place in...

Sociophysics Simulations II: Opinion Dynamics (2005)

The model of Bonabeau et al explains social hierarchies as random: People keep a memory of recent fights, and winners have a higher probability to win again. The question of phase transition and the...

Microscopic and Macroscopic Simulation of Competition between Languages (2005)

Individuals have opinions but can change them under the influence of others. The recent models of Sznajd (missionaries), of Deffuant et al. (negotiators), and of Krause and Hegselmann (opportunists)...

Stauffer, Dietrich, Schulze, Christian

The similarity of the evolution of human languages (or alphabets, bird songs, >...) to biological evolution of species is utilized to study with up to $10^9$ people the rise and fall of languages...

Sociophysics Simulations III: Retirement Demography (2005)

Zekri, Lotfi, Stauffer, Dietrich

This third part of the lecture series deals with the question: Who will pay for your retirement? For Western Europe the answer may be ``nobody'', but for Algeria the demography looks more promising.

Simulation of stem cell survival in small crypts (2005)

Stauffer, Dietrich, Domany, Eytan

Monte Carlo simulations of the number of stem cells in human colon crypts allow for fluctuations which kill the population after sufficiently long times.

Sociophysics Simulations I: Language Competition (2005)

Computer Simulations of Opinions (2005)

Using a bit-string model similar to biological simulations, the competition between different languages is simulated both without and with spatial structure. We compare our agent-based work with...

Fortunato, Santo, Stauffer, Dietrich

We review the opinion dynamics in the computer models of Deffuant et al. (D), of Krause and Hegselmann (KH), and of Sznajd (S). All these models allow for consensus (one final opinion), polarization...

Are Barabasi-Albert networks self-averaging? (2004)

Stauffer, Dietrich, Aharony, Amnon

Yes and no. The size of the largest neighbourhood in a Barabasi-Albert scale-free entwork has string fluctuations of the order of the average value. The number of sites having exactly ten neighbours...

Monte Carlo simulation of the rise and the fall of languages (2004)

Number of spanning clusters at the high-dimensional percolation thresholds (2004)

Similar to biological evolution and speciation we define a language through a string of 8 or 16 bits. The parent gives its language to its children, apart from a random mutation from zero to one or...

Fortunato, Santo, Aharony, Amnon, Coniglio, Antonio, Stauffer, Dietrich

A scaling theory is used to derive the dependence of the average number of spanning clusters at threshold on the lattice size L. This number should become independent of L for dimensions d6 depend...

Discretized Opinion Dynamics of the Deffaunt Model on Scale-Free Networks (2004)

Stauffer, Dietrich, Sousa, Adriano, Schulze, Christian

The consensus model of Deffuant et al is simplified by allowing for many discrete instead of infinitely many continuous opinions, on a directed Barabási-Albert network. A simple scaling law is...

Altruism and Antagonistic Pleiotropy in Penna Ageing Model (2004)

Cebrat, Stanislaw, Stauffer, Dietrich

The Penna ageing model is based on mutation accumulation theory. We show that it also allows for self-organization of antagonistic pleiotropy which helps at young age at the expense of old age. This...

Phase diagram in Bonabeau social hierarchy model with individually different abilities (2004)

Evolving eco-system: a network of networks (2004)

The 1995 model of Bonabeau et al is generalized by giving each individual a different ability to win or lose a fight. We also introduce different groups such that the losers of fights between...

Evolutionary ecology in-silico:evolving foodwebs, migrating population and speciation (2004)

Ecology and evolution are inseparable. Motivated by some recent experiments, we have developed models of evolutionary ecology from the perspective of dynamic networks. In these models, in addition to...

Stauffer, Dietrich, Kunwar, Ambarish, Chowdhury, Debashish

We have generalized our ``unified'' model of evolutionary ecology by taking into account the possible movements of the organisms from one ``patch'' to another within the same eco-system. We model the...

The Coevolution of Individual Economic Characteristics and Socioeconomic Networks (2004)

Stauffer, Dietrich, Hohnisch, Martin, Pittnauer, Sabine

The opinion dynamics of economic agents is modeled with the link structure influenced by the resulting opinions: Links between people of nearly the same opinion are more stable than those between...

Socioeconomic Interaction and Swings in Business Confidence Indicators (2003)

Hohnisch, Martin, Pittnauer, Sabine, Solomon, Sorin, Stauffer, Dietrich

We propose a stochastic model of interactive formation of individual expectations regarding the business climate in an industry. Our model is motivated by a business climate survey cond ucted since...

Genetic Paralog Analysis and Simulations (2003)

Cebrat, Stanislaw, Radomski, Jan P., Stauffer, Dietrich

Using Monte Carlo methods, we simulated the effects of bias in generation and elimination of paralogs on the size distribution of paralog groups. It was found that the function describing the decay...

Computer simulations of history of life: speciation, emergence of complex species from simpler organisms, and extinctions (2003)

Simple Simulation of Magnetic Structure for Nanoclusters (2003)

We propose a generic model of eco-systems, with a {\it hierarchical} food web structure. In our computer simulations we let the eco-system evolve continuously for so long that that we can monitor...

Proykova, Ana, Stauffer, Dietrich

A simple discrete model for magnetic structures of chromium nanoclusters, found with the help of local-spin DFT by Kohl and Bertsch, still confirms their conclusion that in most of the clusters the...

Introduction to Statistical Physics outside Physics (2003)

The Complexity of Biological Ageing (2003)

We review the possibilities and difficulties for statistical physicists if they apply their methods to biology, economics, or sociology.

Percolation-Based Model of New-Product Diffusion with Macroscopic Feedback Effects (2003)

The present review deals with the computer simulation of biological ageing as well as its demographic consequences for industrialized societies.

Hohnisch, Martin, Pittnauer, Sabine, Stauffer, Dietrich

This paper proposes a percolation-based model of new-product diffusion in the spirit of Solomon et al. (2000) and Goldenberg et al. (2000). A consumer buys the new product if she has formed her...

How many different parties can join into one stable government ? (2003)

How to convince others ? Monte Carlo simulations of the Sznajd model (2003)

Monte Carlo simulations of the Sznajd model with bounded confidence for varying dimensions show that the probability to reach a consensus in d-dimensional lattices depends only weakly on d. but...

Unified "micro"- and "macro-" evolution of eco-systems: Self-organization of a dynamic network (2003)

In the Sznajd model of 2000, a pair of neighbouring agents on a square lattice convinces its six neighbours of the pair opinion if and only if the two agents of the pair share the same opinion. It...

Stauffer, Dietrich, Chowdhury, Debashish

Very recently we have developed a dynamic network model for eco-systems that achieved ``unification'' of ``micro'' and ``macro''-evolution. We now propose an extension of our model so as to stabilize...

Cellular Automata Simulation of Medication-Induced Autoimmune Diseases (2003)

Stauffer, Dietrich, Proykova, Ana

We implement the cellular automata model proposed by Stauffer and Weisbuch in 1992 to describe the response of the immune system to antigens in the presence of medications. The model contains two...

A food-web based unified model of "macro"- and "micro-" evolution (2003)

A Market of Inhomogeneous Threshold Cellular Automata (2003)

We incorporate the generic hierarchical architecture of foodwebs into a "{\it unified}" model that describes both "micro" and "macro" evolutions within a single theoretical framework. This model...

Stauffer, Dietrich, Weisbuch, Gerard

This article summarizes some physics aspects of the market model of Weisbuch and Stauffer, Physica A (2003): How do demand and quality expectation adjust to each other in a buyer dominated market...

Associative Recall in Non-Randomly Diluted Neuronal Networks (2003)

Costa, Luciano Da Fontoura, Stauffer, Dietrich

The potential for associative recall of diluted neuronal networks is investigated with respect to several biologically relevant configurations, more specifically the position of the cells along the...

Anomalous diffusion at percolation threshold in high dimensions on 10^18 sites (2003)

Osterkamp, Dirk, Stauffer, Dietrich, Aharony, Amnon

Using an inverse of the standard linear congruential random number generator, large randomly occupied lattices can be visited by a random walker without having to determine the occupation status of...

Efficient Hopfield pattern recognition on a scale-free neural network (2002)

Stauffer, Dietrich, Aharony, Amnon, Costa, Luciano Da Fontoura, Adler, Joan

Neural networks are supposed to recognise blurred images (or patterns) of $N$ pixels (bits) each. Application of the network to an initial blurred version of one of $P$ pre-assigned patterns should...

Adjustment and social choice (2002)

Sociophysics Simulations (2002)

We discuss the influence of information contagion on the dynamics of choices in social networks of heterogeneous buyers. Starting from an inhomogeneous cellular automata model of buyers dynamics, we...

Phase transition in hierarchy model of Bonabeau et al (2002)

Reviews models of Bonabeau et al and Sznajd et al

Simulation consensus model of never changed opinions in Sznajd consensus model using multi-spin coding (2002)

The model of Bonabeau explains the emergence of social hierarchies from the memory of fights in an initially egalitarian society. Introducing a feedback from the social inequality into the...

Frustration from Simultaneous Updating in Sznajd Consensus Model (2002)

The density of never changed opinions during the Sznajd consensus-finding process decays with time t as 1/t^{theta}. We find theta ~= 3/8 for a chain, compatible with the exact Ising result of...

Sole-Manrubia model of biological evolution: some new insights (2002)

In the Sznajd model of 2000, a pair of neighbouring agents on a square lattice convinces its six neighbours of the pair opinion iff the two agents of the pair share the same opinion. Now we replace...

Power of the power-laws: lessons from unification of small and large time scales for evolution (2002)

The Sole-Manrubia model of ``macro''-evolution describes the origination, evolution and extinction of species on geological time scales. We report some properties of this model which provide deep...

Chowdhury, Debashish, Stauffer, Dietrich, Kunwar, Ambarish

We develop a ``unified'' model that describes both ``micro'' and ``macro'' evolutions within a single theoretical framework. The eco-system is described as a dynamic network; the population dynamics...

Simple tools for extrapolations of human mortality in rich countries (2002)

Percolation and Galam Theory of Minority Opinion Spreading (2002)

Suitable assumptions for the Gompertz mortality law take into account the break in the time development observed recently by Wilmoth et al. They show how a drastic reduction in the birth rate and...

Social Percolation and the Influence of Mass Media (2002)

The way in which an opinion rejecting reform can finally become the consensus of everyone was studied by Galam (2002) in a probabilistic model. We now replace his clusters by those formed via random...

Proykova, Ana, Stauffer, Dietrich

Mass media shift the percolative phase transition observed in the marketing model of Solomon and Weisbuch.

Better be third then second in a search for a majority opinion (2002)

Monte Carlo simulations of Sznajd models (2002)

Monte Carlo simulations of a Sznajd model show that if a near-consensus is formed out of four initially equally widespread opinions, the one which at intermediate times is second in the number of...

Monte Carlo Simulations of Sznajd Models (2002)

The Sznajd model in less than a year has found several followers. An isolated person does not convince others; a group of people sharing the same opinions influences the neighbours much more easily....

Scaling in a simple model for surface growth in a random medium (2002)

Aharony, Amnon, Stauffer, Dietrich

Surface growth in random media is usually governed by both the surface tension and the random local forces. Simulations on lattices mimic the former by imposing a maximum gradient $m$ on the surface...

Adjustment and social choice (2002)

Adjustment and social choice (2002)

We discuss the influence of information contagion on the dynamics of choices in social networks of heterogeneous buyers. Starting from an inhomogeneous cellular automata model of buyers dynamics, we...

Ferromagnetic Phase Transition in Barabasi-Albert Networks (2001)

We discuss the influence of information contagion on the dynamics of choices in social networks of heterogeneous buyers. Starting from an inhomogeneous cellular automata model of buyers dynamics, we...

Aleksiejuk, Agata, Holyst, Janusz A., Stauffer, Dietrich

Ising spins put onto a Barabasi-Albert scale-free network show an effective phase transition from ferromagnetism to paramagnetism upon heating, with an effective critical temperature increasing as...

Nucleation of Market Shocks in Sornette-Ide model (2001)

Proykova, Ana, Roussenova, Lena, Stauffer, Dietrich

The Sornette-Ide differential equation of herding and rational trader behaviour together with very small random noise is shown to lead to crashes or bubbles where the price change goes to infinity...

Social Effects in Simple Computer Model of Ageing (2001)

Stauffer, Dietrich, Radomski, Jan P.

A simple evolutionary model for biological ageing is modified such that it requires a minimum population for survival, like in human society. This social effect leads to a transition between...

Dynamics of a simple evolutionary process (2001)

Stauffer, Dietrich, Newman, M. E. J.

We study the simple evolutionary process in which we repeatedly find the least fit agent in a population of agents and give it a new fitness which is chosen independently at random from a specified...

Gompertz law in simple computer model of aging of biological population (2001)

Makowiec, Danuta, Stauffer, Dietrich, Zielinski, Mariusz

It is shown that if the computer model of biological ageing proposed by Stauffer is modified such that the late reproduction is privileged then the Gompertz law of exponential increase of mortality...

Time-reversal asymmetry in Cont-Bouchaud stock market model (2001)

Chang, Iksoo, Stauffer, Dietrich

The percolation model of stock market speculation allows an asymmetry (in the return distribution) leading to fast downward crashes and slow upward recovery. We see more small upturns and more...

Computer simulations for biological aging and sexual reproduction (2001)

STAUFFER,DIETRICH, OLIVEIRA,SUZANA MOSS DE, PENNA,THADEU J.P., MARTINS,JORGE S. SÁ

The sexual version of the Penna model of biological aging, simulated since 1996, is compared here with alternative forms of reproduction as well as with models not involving aging. In particular we...

Spin Domains Generate Hierarchical Ground State Structure in J = ±1 Spin Glasses (2001)

Domany, Eytan, Hartmann, Alexander K., Hed, Guy, Stauffer, Dietrich

Stochastic Penna model for biological aging (2000)

Huang, Zhi-Feng, Stauffer, Dietrich

A stochastic genetic model for biological aging is introduced bridging the gap between the bit-string Penna model and the Pletcher-Neuhauser approach. The phenomenon of exponentially increasing...

Spin Domains Generate Hierarchical Ground State Structure in J=+/-1 Spin Glasses (2000)

Hed, Guy, Hartmann, Alexander K., Stauffer, Dietrich, Domany, Eytan

Unbiased samples of ground states were generated for the short-range Ising spin glass with Jij=+/-1, in three dimensions. Clustering the ground states revealed their hierarchical structure, which is...

Social Percolation on Inhomogeneous Spanning Network (2000)

Gupta, Abhijit Kar, Stauffer, Dietrich

The Social Percolation model recently proposed by Solomon et al. is studied on the Ising correlated inhomogeneous network. The dynamics in this is studied so as to understand the role of correlations...

Social percolation on inhomogenous spanning network (2000)

Gupta, Abhijit Kar, Stauffer, Dietrich

Restricted Access.

Cross-linking of micelles by gemini surfactants (1999)

Maiti, Prabal K., Kremer, Kurt, Flimm, Oliver, Chowdhury, Debashish, Stauffer, Dietrich

We investigate the effects of gemini surfactants, telechelic chain and lipids on the nature of micelles formed by conventional single-tail surfactants in water by carrying out Monte Carlo...

Re-examination of seven-dimensional site percolation thresholds (1999)

Stauffer, Dietrich, Ziff, Robert M.

Monte Carlo simulations alone could not clarify the corrections to scaling for the size-dependent p_c(L) above the upper critical dimension. Including the previous series estimate for the bulk...

Self-Organized Percolation Model for Stock Market Fluctuations (1999)

Stauffer, Dietrich, Sornette, D.

In the Cont-Bouchaud model [cond-mat/9712318] of stock markets, percolation clusters act as buying or selling investors and their statistics controls that of the price variations. Rather than fixing...

Periodicity-dependent stiffness of periodic hydrophilic-hydrophobic hetero-polymers (1999)

Chowdhury, Debashish, Stauffer, Dietrich, Strey, Reinhard

From extensive Monte Carlo simulations of a Larson model of perfectly periodic heteropolymers (PHP) in water a striking stiffening is observed as the period of the alternating hydrophobic and...

Cours de Physique (de Newton à Mandelbrot) (1999)

Stauffer, Dietrich, Stanley, H. Eugene, Lesne, Annick

Life, Love and Death: Models of Biological Reproduction and Aging (1999)

Dietrich Stauffer

sure will soon eliminate most of these mutations from the population. If, on the other hand, an inherited mutation causes deadly cancer at age 60, most of us will not get new children anymore, no...

A generalized spin model of financial markets (1998)