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831.
832.
833.
YUSUKE KANAZAWA 《The Journal of mathematical sociology》2013,37(2):187-204
It is rational for individuals to defect in social dilemmas. However, sometimes individuals display cooperative behaviors. This article focuses on one psychological mechanism proposed by some researchers as a promoter of cooperation—projection. Projection is a psychological mechanism that leads an individual to expect others to behave as he or she behaves. I model the emergence of cooperation in society through agent-based simulations. Results of the simulations suggest that projection evolves and promotes cooperation in a society where both structural embeddedness and opportunity costs are high, or where structural embeddedness is moderate and opportunity costs are low. I discuss the implication of the simulation results for studies of social dilemmas and trust. 相似文献
834.
Jeffrey C. Johnson James S. Boster Lawrence A. Palinkas 《The Journal of mathematical sociology》2013,37(2-3):89-121
This article reports on the evolution of network structure as it relates to formal and informal social roles in well-bounded, isolated groups. Research was conducted at the Amundsen-Scott South Pole Station. Data were collected on crewmembers' networks of social interaction over each of three winter-over periods, when the station is completely isolated. In addition, data were collectedon the informal roles played by crewmembers (e.g., instrumental leadership, expressive leadership). The study found that globally coherent networks in winter-over groups were associated with group consensus on the presence of critically important informal social roles (e.g., expressive leadership)where global coherence is the extent to which a network forms a single group composed of a unitary core and periphery as opposed to being factionalized into two or more subgroups. Conversely, the evolution of multiple subgroups was associated with the absence of consensus on critical informal social roles, above all the critically important role of instrumental leader. 相似文献
835.
Artibano Micali 《代数通讯》2013,41(8):2371-2385
We extend the concept of the “join” to the case of infinitely many weighted algebras. We study the problem of its uniqueness (up to weighted isomorphism) which gives rise to a natural notion of homogeneous weighted algebras. We show that several classes of weighted algebras coming from genetics are homogeneous and that homogeneity is preserved by duplication. Finally, we examine some well-known weighted algebras satisfying identities, as Bernstein, train, and evolution algebras. 相似文献
836.
Gonzalo Alduncin 《Numerical Functional Analysis & Optimization》2013,34(3):305-328
Optimal control of nonlinear transport-flow mixed variational problems are studied qualitatively, and the solvability analysis of the transport and flow mixed state systems is performed on the basis of primal and dual evolution duality principles. Corresponding primal and dual mixed optimality conditions are established by the application of some fundamental perturbation conjugate duality results recently proposed [8]. Further, for computational purposes, two- and three-field proximation penalty-duality algorithms in the resolution of the mixed optimality conditions are finally presented and discussed. 相似文献
837.
Codon phylogenetic distance 总被引:1,自引:0,他引:1
Michel CJ 《Computational Biology and Chemistry》2007,31(1):36-43
We develop here an analytical evolution model based on a trinucleotide mutation matrix 64x64 with nine substitution parameters associated with the three types of substitutions in the three trinucleotide sites and with non-zero elements on its main diagonal. It generalizes the previous models based on the nucleotide mutation matrices 4x4 and the trinucleotide mutation matrices 64x64 with zero elements on its main diagonal. It determines at some time t the exact occurrence probabilities of trinucleotides mutating randomly according to these nine substitution parameters. Furthermore, applications of this model allow to generalize an evolutionary analytical solution of the common circular code of eukaryotes and prokaryotes and also to derive a codon phylogenetic distance. 相似文献
838.
839.
Existence of solutions for a class of doubly nonlinear evolution equations of second order is proven by studying a full discretization. The discretization combines a time stepping on a non-uniform time grid, which generalizes the well-known Störmer-Verlet scheme, with an internal approximation scheme.The linear operator acting on the zero-order term is supposed to induce an inner product, whereas the nonlinear time-dependent operator acting on the first-order time derivative is assumed to be hemicontinuous, monotone and coercive (up to some additive shift), and to fulfill a certain growth condition. The analysis also extends to the case of additional nonlinear perturbations of both the operators, provided the perturbations satisfy a certain growth and a local Hölder-type continuity condition. A priori estimates are then derived in abstract fractional Sobolev spaces.Convergence in a weak sense is shown for piecewise polynomial prolongations in time of the fully discrete solutions under suitable requirements on the sequence of time grids. 相似文献
840.
Houria TrikiT. Hayat Omar M. AldossaryAnjan Biswas 《Applied mathematics and computation》2011,217(21):8852-8855
This paper obtains the solitary wave as well as the shock wave solutions to the second order wave equation of Korteweg-de Vries type that was first proposed in 2002. The ansatz method is used to retrieve these solutions. The domain restrictions as well as the parameter regimes are all identified in the process of obtaining the solution. 相似文献