Intervening duality and bargaining with a farmer–landowner example

In a 1995 paper in this journal I introduced the intervening duality idea and showed how it could be used to analyse a simple matching pennies game in which each of two players anticipated a gain from a single toss of a “fair” coin. This paper generalises that earlier analysis and results. Firstly it introduces more general production related classes of cases in which individuals may seek to gain by making themselves dual to the duals of an intervening specification of production plans, strategies and payoffs. Secondly, through this explicitly economic context, the paper introduces and analyses issues pertaining to framing (e.g. with reference to choices of production of crops vs. “setaside”), bargaining and learning.     

Learning of shared attention in sociable robotics

Sociable robots are embodied agents that are part of a heterogeneous society of robots and humans. They should be able to recognize human beings and each other, and to engage in social interactions. The use of a robotic architecture may strongly reduce the time and effort required to construct a sociable robot. Such architecture must have structures and mechanisms to allow social interaction, behavior control and learning from environment. Learning processes described on Science of Behavior Analysis may lead to the development of promising methods and structures for constructing robots able to behave socially and learn through interactions from the environment by a process of contingency learning. In this paper, we present a robotic architecture inspired from Behavior Analysis. Methods and structures of the proposed architecture, including a hybrid knowledge representation, are presented and discussed. The architecture has been evaluated in the context of a nontrivial real problem: the learning of the shared attention, employing an interactive robotic head. The learning capabilities of this architecture have been analyzed by observing the robot interacting with the human and the environment. The obtained results show that the robotic architecture is able to produce appropriate behavior and to learn from social interaction.     

Small-group searches for mathematical proofs and individual reconstructions of mathematical concepts

This is a study of mathematics students working in small groups. Our research methodology allows us to examine how individual ideas develop in a social context. The research perspective used in this study is based on a co-constructive view of learning. Groups of three or four undergraduate mathematics majors, with prior experience writing mathematical proofs together, were asked to prove three statements. Computer software, such as Geometers Sketchpad, was available. Group work sessions were videotaped. Later, individuals viewed segments of the group video and were asked to reflect on group activities. Students in some groups did not share a common conception of proof, which seemed to hamper their collaboration. We observed interactions that fit with the co-constructive theory, with bidirectional interactions that shaped both group and individual conceptions of the tasks. These changes in understanding may result from parallel and successive internalization and externalization of ideas by individuals in a social context.     

The destabilizing effects of the social norm to work under a social security system

We study employment dynamics in an OLG model with unemployment benefits financed by taxing wages, and with a defined contribution plan. The novelty with respect to recent studies of the effects of social security in this context is that we introduce a social norm to work, shaping the worker’s participation decision, and hence affecting the reservation wage. We find that a strong social norm to work destabilizes conventional wisdom by reversing the negative effects of social security on employment, and destabilizes the economy by facilitating the emergence of endogenous fluctuations.     

Evolution of shame as an adaptation to social punishment and its contribution to social cohesiveness

Feelings of shame are common among humans although shameless individuals do not seem to be handicapped in achieving social success in life. What then is the adaptive value of shame? How can shame have evolved? Here I simulate shame as the emotion that induces an increase in pro‐social behavior after receiving social punishment. Simulations with the agent‐based model, Sociodynamica, show that shame is evolutionary stable in a context of individual selection, without the need for including group selection as an evolutionary force. The adaptive advantage of shame is based on the fact that it increases flexibility to the shameful individual, allowing it to act selfish if the probabilities of being punished are low and achieving a reduction in the costs of social punishment when frequent punishment is likely. The results show that shame, together with pro‐social punishment and social cooperation, produce a fluctuating dynamics of social cooperation, achieving long periods where the populations stabilizes pro‐social behavior interspersed with periods where selfish behavior predominates. This temporal stabilization of pro‐social behavior might provide societies with sufficient time to build institutions that might stabilize sustainable pro‐social behavior. © 2008 Wiley Periodicals, Inc. Complexity, 2008     

Interpersonal influence and attitude change toward conformity in small groups: A social psychological model

Friedkin and Johnsen's interpersonal influence model (Friedkin, 1999; Friedkin and Johnsen, 1999) does not specify the mechanism of social influence, how they affect each other. I introduce some social psychological theories and bring those into Friedkin's model so that the emergence of social influence through the social psychological process is clearly described. At the same time, the possibility of reactance against the persuasion is introduced. Reactance plays a role for the people in the group to have similar but not identical attitudes.     

Competitive insurance pricing with complete information,loss-averse utility and finitely many policies

In a recent paper, Ramsay and Oguledo (2012) show that in a competitive insurance market with complete information about individuals’ accident probabilities and production costs, which are proportional to the amount of insurance purchased and to the premium charged, only individuals whose accident probability is in a medium range are insurable and desire insurance. The purpose of this paper is to complement the analysis of Ramsay and Oguledo by considering production costs which are proportional to the number of policies offered by an insurer. In addition to the result of Ramsay and Oguledo we show that the group of individuals who obtain insurance is partitioned into several subgroups, where each subgroup is offered the same insurance policy. To derive this result we introduce the concept of incentive compatibility which ensures that an individual has no incentive to buy another policy. Assuming that individuals have loss-averse utility, we fully characterize the boundaries of these subgroups as the result of an undercutting process in premiums between the insurers.     

An automated planning engine for biopharmaceutical production

We introduce an optimization-based production planning tool for the biotechnology industry. The industry’s planning problem is unusually challenging because the entire production process is regulated by multiple external agencies – such as the US Food and Drug Administration – representing countries where the biopharmaceutical is to be sold. The model is structured to precisely capture the constraints imposed by current and projected regulatory approvals of processes and facilities, as well as capturing the outcomes of quality testing and processing options, facility capacities and initial status of work-in-process. The result is a supply chain “Planning Engine” that generates capacity-feasible batch processing schedules for each production facility within the biomanufacturing supply chain and an availability schedule for finished product against a known set of demands and regulations. Developing the formulation based on distinct time grids tailored for each facility, planning problems with more than 27,000 boolean variables, more than 130,000 linear variables and more than 80,000 constraints are automatically formulated and solved within a few hours. The Planning Engine’s development and implementation at Bayer Healthcare’s Berkeley, CA manufacturing site is described.     

Diffuse Interface Methods for Multiple Phase Materials: An Energetic Variational Approach

In this paper, we introduce a diffuse interface model for describing the dynamics of mixtures involving multiple (two or more) phases. The coupled hydrodynamical system is derived through an energetic variational approach. The total energy of the system includes the kinetic energy and the mixing (interfacial) energies. The least action principle (or the principle of virtual work) is applied to derive the conservative part of the dynamics, with a focus on the reversible part of the stress tensor arising from the mixing energies. The dissipative part of the dynamics is then introduced through a dissipation function in the energy law, in line with Onsager's principle of maximum dissipation. The final system, formed by a set of coupled time-dependent partial differential equations, reflects a balance among various conservative and dissipative forces and governs the evolution of velocity and phase fields. To demonstrate the applicability of the proposed model, a few two-dimensional simulations have been carried out, including (1) the force balance at the three-phase contact line in equilibrium, (2) a rising bubble penetrating a fluid-fluid interface, and (3) a solid particle falling in a binary fluid. The effects of slip at solid surface have been examined in connection with contact line motion and a pinch-off phenomenon.     

Modeling opinion formation in the kinetic theory of active particles I: spontaneous trend

The kinetic theory of active particles is used to model the formation and evolution of opinions in a structured population. The spatial structure is modeled by a network whose nodes mimic the geographic distribution of individuals, while the functional subsystems present in each node group together elements sharing a common orientation. In this paper we introduce a model, based on nonlinear and nonlinearly additive interactions among individuals, subsystems and nodes, related to the spontaneous evolution of opinion concerning given specific issues. Numerical solutions in a model situation not related with real data show how the mutual interactions are able to drive the subsystems opinion toward the emergence of collective structures characterizing this kind of complex systems.     

Influence maximization with partial feedback

The goal of Influence maximization (IM) is to select a set of most influential users in a social network subject to a budget constraint. In this work, we propose to study the adaptive IM problem under partial-feedback model. Our main contribution in this paper is to introduce a novel adaptive policy with bounded approximation ratio. One nice feature of our policy is that we can balance the delay and performance tradeoff by adjusting the value of a controlling parameter.     

油田产量构成的多阶段多目标优化

为了确保中后期原油稳产,如何将油田总产量合理细分到各采油厂成为油田开发规划面临的重要问题.建立了油田产量构成的多阶段多目标优化模型,将油田总产量按照产量构成的类型分配给各分项产量,进一步将各分项产量分配到各采油厂.结果表明,通过多阶段优化,在确保油田总产量稳定提高的同时,油田的总成本在两个阶段都有所下降,油田效益提高;此外,油田总产量目标被细分到了各采油厂的各分项产量,为油田决策者下达具体的产量指标提供了依据,以便油厂根据自身实际优化开发指标,完成油田下达的产量任务.     

The Social Construction of Authority Among Peers and Its Implications for Collaborative Mathematics Problem Solving

This article describes a study of how students construct relations of authority during dyadic mathematical work and how teachers’ interactions with students during small group conferences affect subsequent student dynamics. Drawing on the influence framework (Engle, Langer-Osuna, & McKinney de Royston, 2014), I examined interactions when students appropriated their peers’ ideas during collaborative mathematical problem solving and noted that each moment tended to follow particular interactions around authority. Notably, social and intellectual forms of authority became linked in ways that were directly related to how students’ ideas and behaviors were evaluated by the teacher. I close by discussing how the study of authority and influence offers fertile analytic ground to generate new understandings about collaborative student work in mathematics classrooms.     

The development and interaction of terrorist and fanatic groups

Through the mathematical study of two models we quantify some of the theories of co-development and co-existence of focused groups in the social sciences. This work attempts to develop the mathematical framework behind the social sciences of community formation. By using well developed theories and concepts from ecology and epidemiology we hope to extend the theoretical framework of organizing and self-organizing social groups and communities, including terrorist groups. The main goal of our work is to gain insight into the role of recruitment and retention in the formation and survival of social organizations. Understanding the underlining mechanisms of the spread of ideologies under competition is a fundamental component of this work. Here contacts between core and non-core individuals extend beyond its physical meaning to include indirect interaction and spread of ideas through phone conversations, emails, media sources and other similar mean. This work focuses on the dynamics of formation of interest groups, either ideological, economical or ecological and thus we explore the questions such as, how do interest groups initiate and co-develop by interacting within a common environment and how do they sustain themselves? Our results show that building and maintaining the core group is essential for the existence and survival of an extreme ideology. Our research also indicates that in the absence of competitive ability (i.e., ability to take from the other core group or share prospective members) the social organization or group that is more committed to its group ideology and manages to strike the right balance between investment in recruitment and retention will prevail. Thus under no cross interaction between two social groups a single trade-off (of these efforts) can support only a single organization. The more efforts that an organization implements to recruit and retain its members the more effective it will be in transmitting the ideology to other vulnerable individuals and thus converting them to believers.     

Exploring a Multicriteria Approach to Production Scheduling

A current problem in production scheduling is related to the multi-criteria nature of the task. No matter how effective a heuristic or algorithm is, there remains a need to use human judgement to find a balance between an organization's conflicting objectives, such as meeting due-dates and minimizing work-in-progress. The problem is that heuristics do not have convenient input parameters that relate to these organizational objectives. In this paper we introduce the concept of a ‘control mechanism’ that would allow the scheduler to direct the search for a schedule on the basis of preferences with respect to multiple performance criteria. The feasibility of such a system is dependent on there being a predictable relationship between the input parameters of the scheduling heuristic and the performance measures. We describe a prototype Visual Interactive implementation of the proposed system, present the results of some initial experimental work, which indicates that the method has some potential, and comment on potentially fruitful areas for further research.     

Cooperation in harsh environments and the emergence of spatial patterns

This paper concerns the confluence of two important areas of research in mathematical biology: spatial pattern formation and cooperative dilemmas. Mechanisms through which social organisms form spatial patterns are not fully understood. Prior work connecting cooperation and pattern formation has often included unrealistic assumptions that shed doubt on the applicability of those models toward understanding real biological patterns. I investigated a more biologically realistic model of cooperation among social actors. The environment is harsh, so that interactions with cooperators are strictly needed to survive. Harshness is implemented via a constant energy deduction. I show that this model can generate spatial patterns similar to those seen in many naturally-occuring systems. Moreover, for each payoff matrix there is an associated critical value of the energy deduction that separates two distinct dynamical processes. In low-harshness environments, the growth of cooperator clusters is impeded by defectors, but these clusters gradually expand to form dense dendritic patterns. In very harsh environments, cooperators expand rapidly but defectors can subsequently make inroads to form reticulated patterns. The resulting web-like patterns are reminiscent of transportation networks observed in slime mold colonies and other biological systems.     

Dissonance Minimization as a Microfoundation of Social Influence in Models of Opinion Formation

Models of opinion formation are used to investigate many collective phenomena. While social influence often constitutes a basic mechanism, its implementation differs between the models. In this article, we provide a general framework of social influence based on dissonance minimization. We only premise that individuals strive to minimize dissonance resulting from different opinions compared to individuals in a given social network. Within a game theoretic context, we show that our concept of dissonance minimization resembles a coordination process when interactions are homogeneous. We further show that different models of opinion formation can be represented as best response dynamics within our framework. Thus, we offer a unifying perspective on these heterogeneous models and link them to rational choice theory.     

May简单多数规则的描述

本文将Asan就两个备选对象定义的弱路径独立性和Woeginger就两个备选对象定义的亚社会可约性概念推广到任意备选对象集,在给定的有限参与人集及任意备选对象集的条件下,讨论了一社会福利函数是简单多数规则的充要条件,从而推广了Asan和Woeginger的工作.     

Two phase transitions for the contact process on small worlds

In our version of Watts and Strogatz’s small world model, space is a d$d$-dimensional torus in which each individual has in addition exactly one long-range neighbor chosen at random from the grid. This modification is natural if one thinks of a town where an individual’s interactions at school, at work, or in social situations introduce long-range connections. However, this change dramatically alters the behavior of the contact process, producing two phase transitions. We establish this by relating the small world to an infinite “big world” graph where the contact process behavior is similar to the contact process on a tree. We then consider the contact process on a slightly modified small world model in order to show that its behavior is decidedly different from that of the contact process on a tree.     

The Promotion and Evolution of Cooperation Through Projection: Implications for Social Dilemmas and Trust

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.