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Results for criterions:- Topic: Process
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Results n° 1 to 8 of 20 matches
| Title |
The Arc-sinus law |
| Author |
MORLAT Georges, BARBUT Marc, (Réalisation Rossi Raoul) |
| Keywords |
André Désiré, Arc-sinus, Ballot, Counting of the votes, Lévy Paul |
| Topics |
Probabilities, Process, Random variable, Statistics, Voting |
| Abstract |
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| Number |
1183, Fall 2008, special issue: Video flashback |
| Language |
 French |
| Title |
Demographic time series: long memory or regime switching? |
| Author |
BOUTAHAR Mohamed, AJMI Ahdi Noomen |
| Keywords |
ARFIMA process, Demography, Long memory, Structural changes |
| Topics |
Demography, Modelling, Process, Time Series |
| Abstract |
A few works have recently advocated the use of the long memory concept in modelling demography time series. However, the study of such series shows evidence for regime switching which was pointed out by demographers many years ago. As in an economic framework, one may ask the following question, what is the genuine process describing such series: long memory or regime switching? |
| Number |
181, Spring 2008 |
| Language |
French | Read the article
| Title |
Actions, interactions and structure in the emergence of educational stratification: A discrete choices model with externalities |
| Author |
MANZO Gianluca |
| Keywords |
Agents-based models, Educational choices, Emergence, Heterogeneity, Interdependency, Mathematical model, Statistical analysis |
| Topics |
Concentration, Methodology, Modelling, Process, Social Psychology, Sociology |
| Abstract |
The article presents a generating model of educational stratification which aims analytically decompose the emergence of this one in terms of individual choices, of interactions direct and indirect between them and of structural constraints which weigh on the actors. The model suggested takes as a starting point the framework of "discrete choices models with externalities". By this one, it proposes to refine the most usually adopted theorizations in the quantitative studies of the educational stratification, namely the «rational educational choice approach». The article guides the reader through the stages of construction and study of the model. In the first time, the sociological ideas which melt this model are exposed. In the second time, their mathematical formalization, initially, their computational translation (in an agents-based system), then, are dissected. In the third time, the results of the deductive treatment by simulation of the theoretical model are elaborate inductively. On the one hand, the "simulated" data are confronted with French and Italian empirical data to establish the degree of conformity between the theoretical educational stratification and empirical one. In addition, one studies the data produced by the model under experimental conditions different from those adopted to reproduce the empirical data: namely, the role of the interindividual variability in the genesis of the educational stratification is explored. The article is concluded by a discussion about the limits of our formal model. |
| Number |
175, Fall 2006 |
| Language |
French | Read the article
| Title |
Building models for social space: neighourhood-based models for social networks and affiliation structures |
| Author |
PATTISON Philippa, ROBINS Garry |
| Keywords |
Affiliation, Dynamic, Neighbourhood, Random graph, Social space |
| Topics |
Graphs, Modelling, Networks, Probabilities, Process, Social Sciences, Stochastic Processes |
| Abstract |
We propose a quantitative relational framework for social space. We suggest that social space cannot be specified simply in geographical, network or sociocultural terms but, rather, requires an understanding of the interdependence of relationships among different types of social entities, such as persons, groups, sociocultural resources and places. We also suggest that social space cannot be regarded as fixed: unlike the Euclidean space of Newtonian mechanics, social space is constructed, at least in part, by the social processes that it supports. In the general stochastic relational framework that we propose, relationships among social entities are regarded as the fundamental elements of social space and observed relational entities are viewed as the outcome of processes that occur in overlapping local relational neighbourhoods. Each neighbourhood corresponds to a subset of possible relational entities and is conceived as a possible site of social interaction. We show how special cases of this framework yield hierarchies of models for social networks and for affiliation structures. We also sketch some next steps in the development of this framework. |
| Number |
168, Winter 2004, special issue: Social networks |
| Language |
 English | Read the article
| Title |
The mathematics of population from Lambert to Lotka |
| Author |
VERON Jacques |
| Keywords |
Law of mortality, Logistic law, Malthusian population, Mean length life, Median length of life, Normal length of life, Population with a stable age distribution |
| Topics |
Demography, Historical demography - History of Demography, History of sciences, Logistic Curve, Probabilities, Process |
| Abstract |
In 1825, Benjamin Gompertz gives a mathematical formulation of the law of mortality, which, following a former one by Lambert (1772), relates survival to age. In 1844, Pierre-François Verhulst put forward a model of population growth in which the rate of growth reduces when the size of the population increases: it is the logistic function (Lotka will, from 1907, contribute largely to this field of population dynamics, especially on the stability of the age composition of a population).During the 19th century too, Wilhelm Lexis gives estimations of the normal length of human life, which would be observed in the absence of premature deaths, in childhood and adulthood. |
| Number |
159, Fall 2002 |
| Language |
French | Read the article
| Title |
Viable strategies among fishermen analysed by the anthropologist Fredrik Barth |
| Author |
BONNEUIL Noël, SAINT-PIERRE Patrick |
| Keywords |
None |
| Topics |
Algorithms - Algorithmic Theory, Anthropology - Ethnology, Decision Theory, Dynamical Systems, Process |
| Abstract |
The anthropologist Fredrik Barth analysed the social forms generated among Norvegian fishermen. His view is well rendered by the mathematical tools of viability theory. The largest set of states from which economic survival is still possible is calculated, as well as the right decision to take at each moment, between risk-taking and following the other vessels. Moreover, the technical condition that the image of the correspondence describing the process at work must be compact, isviolated. We deal with this difficulty and we present the algorithm. |
| Number |
142, Summer 1998 |
| Language |
French | Read the article
| Title |
Parameters in collective decision making models: estimation and sensitivity |
| Author |
SNIJDERS Tom A. B., ZEGGELINK Evelien P.H., STOKMAN Frans-N. |
| Keywords |
None |
| Topics |
Decision Theory, Game Theory, Networks, Process, Social Sciences, Stochastic Processes, Voting |
| Abstract |
Simulation models for collective decision making are based on theoretical and empirical insight in the decision making process, but still contain a number of parameters of which the values are determined ad hoc. For the dynamic access model, some of such parameters are discussed, and it is proposed to extend the utility functions with a random term of which the variance also is an unknown parameter. These parameters can be estimated by fitting model predictions to data, where the predictions can refer to decision outcomes but also to network structure generated as a part of the decision making process. Given the stochastic nature of the model, this parameter estimation can be carried out with the Robbins Monro process. Such fitting is not completely straightforward: statistics must be chosen on which to base the parameter estimation, it is not certain a priori that there will be a solution to the estimating equation and that the Robbins Monro process will converge. The method is illustrated with data from the financial restructuring of a large company. |
| Number |
137, Spring 1997, special issue: A few models for social networks analysis |
| Language |
English | Read the article
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