Narrow Results

Research in network science has shown that many naturally occurring and technologically constructed networks are scale free, that means a power law degree distribution emerges from a growth model in which each new node attaches to the existing network with a probability proportional to its number of links (= degree). Little is known about whether the same principles of local attachment and global properties apply to societies as well. Empirical evidence from six ethnographic case studies shows that complex social networks have significantly lower scaling exponents γ ~ 1 than have been assumed in the past. Apparently humans do not only look for the most prominent players to play with. Moreover cooperation in humans is characterized through reciprocity, the tendency to give to those from whom one has received in the past. Both variables — reciprocity and the scaling exponent — are negatively correlated (r = -0.767, sig = 0.075). If we include this effect in simulations of growing networks, degree distributions emerge that are much closer to those empirically observed. While the proportion of nodes with small degrees decreases drastically as we introduce reciprocity, the scaling exponent is more robust and changes only when a relatively large proportion of attachment decisions follow this rule. If social networks are less scale free than previously assumed this has far reaching implications for policy makers, public health programs and marketing alike.

We study the effects of the reciprocal links on the dynamics of direct Boolean networks with scale-free topology (SFRBNs). By means of the method of the Derrida Plot, we have investigated the SFRBNs characterized by different values of average degree and different values of reciprocity in order to test the behavioral regimes of the system. The following step was to perform numerical simulation with the quenched Kauffman model to study the dynamical properties of critical SFRBNs with ${〈k〉}_c=2$. The distribution of the number of different attractors, the period of the cyclic attractors, the transient duration and the fraction of the frozen nodes, have been studied as a function of the reciprocity and network size. The results presented reveal that reciprocity seems to have no direct effect on the changing of the behavioral regime of SFRBNs with given value of $〈k〉$. On the contrary, we observed that reciprocal links have a profound effect on the dynamic of critical SFRBNs.

We point out that the time–reversal–invariant explanation of the recently observed CPLEAR asymmetry is valid at the level of less than three standard deviations; this asymmetry has been claimed to be the first direct observation of time–reversal–noninvariance in the neutral kaon system. We note how, by avoiding the assumptions made at present, future data may provide model-independent tests of structural T- and CPT-invariances of the neutral kaon complex.

Social relations between people seldom follow regular lattice structures. In the Barabási–Albert model nodes link to the existing network structure with a probability proportional to the number of nodes previously attached. Here, we present an anthropologically motivated interpolation between Erdös–Rényi and Barabási–Albert rules, where people also prefer to help those who helped them in the past and explore some of its properties. The second part of the paper tackles the question how opinions spread through social networks. We restrict our analysis to one end of the spectrum: scale-free networks. We show for two different models how fast and how sustainable single individuals can influence an appreciable fraction of the population through social contacts.

We construct a statistical ensemble of games, wherein each independent subensemble we have two players playing the same game. We derive the mean payoffs per move of the representative players of the game, and we evaluate all the deterministic policies with finite memory. In particular, we show that if one of the players has a generalized tit-for-tat policy, the mean payoff per move of both players is the same, forcing the equalization of the mean payoffs per move. In the case of symmetric, noncooperative and dilemmatic games, we show that generalized tit-for-tat or imitation policies together with the condition of not being the first to defect, leads to the highest mean payoffs per move for the players. Within this approach, it can be decided which policies perform better than others. In particular, it shows that reciprocity in noncooperative iterated games forces equality of mean payoffs. We prove a simple ergodic theorem for symmetric and noncooperative games. The Prisoner's Dilemma and the Hawk–Dove games have been analyzed, and the equilibrium states of the infinitely iterated games have been determined. In infinitely iterated games with the player choosing their moves with equal probabilities, strict Nash solutions are not necessarily reachable equilibrium solutions of games.

By identifying the efficiently radiating acoustic radiation modes of a fluid loaded vibrating structure, the storage requirements of the acoustic impedance matrix for calculation of the sound power using the boundary element method can be greatly reduced. In order to compute the acoustic radiation modes, the impedance matrix needs to be symmetric. However, when using the boundary element method, it is often found that the impedance matrix is not symmetric. This paper describes the origin of the asymmetry of the impedance matrix and presents a simple way to generate symmetry. The introduction of additional errors when symmetrizing the impedance matrix must be avoided. An example is used to demonstrate the behavior of the asymmetry and the effect of symmetrization of the impedance matrix on the sound power. The application of the technique presented in this work to compute the radiated sound power of a submerged marine vessel is discussed.

The Cauchy equation for automorphisms of the unit interval is fulfilled only by the identity mapping. We consider two weakened forms of this Cauchy equation: the reciprocity equation and the n-divisibility equation. Although the solution sets of both functional equations are quite large, requiring that an automorphism is both reciprocal and n-divisible, drastically increases the set of obligatory fixed points. However, increasing n also enlarges the domain on which the automorphism can be chosen freely. We also describe the solution sets of two functional equations that arise by composing the reciprocity and n-divisibility property.

In the last 30 years, several distinguished researchers have proposed and discussed different fuzzy versions of well-known Saaty's Analytic Hierarchy Process (AHP). The paper recently published by K. Zhü in the European Journal of Operational Research heavily criticizes the fuzzy approaches to AHP, claiming the fallacy of all of them. Therefore, it seems to be necessary to clarify whether the criticisms are well-founded or not. The present paper aims to rebut Zhü's claims by showing that the evidences and the reasonings in his paper are very poor and far from proving the fallacy of fuzzy AHP.

Inductive game theory has been developed to explore the origin of beliefs of a person from his accumulated experiences of a game situation. It has been restricted to a person's view of the structure not including another person's thoughts. In this paper, we explore the experiential origin of one's view of the other's beliefs about the game situation, especially about the other's payoffs. We restrict our exploration to a 2-role (strategic) game, which has been recurrently played by two people with occasional role-switching. Each person accumulates experiences of both roles, and these experiences become the source for his transpersonal view about the other. Reciprocity in the sense of role-switching is crucial for deriving his own and the other's beliefs. We also consider how a person can use these views for his behavior revision, and we define an equilibrium called an intrapersonal coordination equilibrium. Based on this, we show that cooperation will emerge as the degree of reciprocity increases.

Although violation of Kirchhoff’s Law of Thermal Radiation has been claimed in a magneto-optic structure, it is shown that Kirchhoff’s Law of Thermal Radiation has not been violated, noting that violation of Kirchhoff’s Law of Thermal Radiation would imply that the Second Law of Thermodynamics has also been violated.

We present a model of social interaction in which actors choose their partners and play the Chicken Game with them. In contrast to most previous models of the coevolution of games and networks, we assume that the actors can employ different actions against different partners. This allows us to derive two different solutions to the coordination and asymmetry problems in the game: egalitarian stationary conventions (based on indirect reciprocity at the network level) and alternating conventions (based on direct reciprocity in dyads). We derive predictions on the occurrence of the possible convention structures and test our theoretical findings in a computerized experiment. The experimental results indicate that the egalitarian conventions indeed emerge and persist and that the alternating conventions are much more likely than the stationary ones. However, although egalitarian in terms of payoffs, the convention structures tend to have hierarchical action distributions.

Knowledge Management (KM) provides a systematic process to help in the creation, transfer and use of knowledge across the university, leading to increased productivity. While KM has been successfully used elsewhere, universities have been late in adopting it. Before a university can initiate KM, it needs to determine if it is ready for KM or not. Through a web-based survey sent to 1263 faculty members from 59 accredited Library and Information Science programs in universities across North America, this study investigated the effect of individual factors of trust, knowledge self-efficacy, collegiality, openness to change and reciprocity on individual readiness to participate in a KM initiative, and the degree to which this affects perceived organisational readiness to adopt KM. 157 valid responses were received. Using structural equation modeling, the study found that apart from trust, all other factors positively affected individual readiness, which was found to affect organisational readiness. Findings should help universities identify opportunities and barriers before they can adopt KM. It should be a useful contribution to the KM literature, especially in the university context.

For a finite set A of positive integers, we study the partition function p_A(n). This function enumerates the partitions of the positive integer n into parts in A. We give simple proofs of some known and unknown identities and congruences for p_A(n). For n in a special residue class, p_A(n) is a polynomial in n. We examine these polynomials for linear factors, and the results are applied to a restricted m-ary partition function. We extend the domain of p_A and prove a reciprocity formula with supplement. In closing we consider an asymptotic formula for p_A(n) and its refinement.

In this paper, we consider an extension of Jacobi’s symbol, the so-called rational $2^k$th power residue symbol. In Sec. 3, we prove a novel generalization of Zolotarev’s lemma. In Secs. 4–6, we show that several hard computational problems are polynomial-time reducible to computing these residue symbols, such as getting nontrivial information about factors of semiprime numbers. We also derive criteria concerning the Quadratic Residuosity Problem.

The history of hydropolitics does not support the claim that the next war shall be about water. The chapter considers a set of variables, including scarcity, geography, relative power, domestic politics, and international water law, to explain the onset of conflict and initiation of cooperation over transboundary waters. Strategies and tactics for promoting cooperation, and eventually an agreement, between riparians are also discussed. After reading this chapter, you will understand that while political disputes over water do take place (and may become most volatile in otherwise unstable regions) they rarely become violent. You will be equipped with evidence showing that for the same reasons that conflict may arise over a shared-water body, cooperation may also come about. You will gain knowledge of several elements that facilitate both conflict and cooperation over transboundary waters. Finally, you will learn about different tactics used to facilitate cooperation and negotiation over transboundary waters, and understand that the intricacies of conflict and cooperation are of highest importance in otherwise precarious regions where a water dispute may aggravate the already tense political environment.

Preferential trade agreements (PTAs) are characterized by liberalization with respect to only a few partners and thus they can potentially clash with, and retard multilateral trade liberalization (MTL). Yet there is almost no systematic evidence on whether the numerous existing PTAs actually affect MTL. We provide a model showing that PTAs hinder MTL unless they entail accession to a customs union with internal transfers. Using product-level tariffs negotiated by the European Union (EU) in the last two multilateral trade rounds we find that several of its PTAs have clashed with its MTL. However, this effect is absent for EU accessions. Moreover, we provide new evidence on the political economy determinants of trade policy in the EU.

Using the menu-auction approach to endogenous determination of tariffs and allowing additionally for lobby formation itself to be endogenous, this paper analyzes the impact of unilateral trade liberalization by one country on its partner's trade policies. We find that such unilateral liberalization may induce reciprocal tariff reductions by the partner country. Intuitively, unilateral liberalization by one country has the effect of increasing the incentives for the export lobby in the partner country to form and to lobby effectively against the import-competing lobby there for lower protection.

This paper shows how unilateral liberalization in one country can increase the voting support for reciprocal reduction in trade barriers in a partner country. When trade policies are determined simultaneously in the two countries, we show the possibility of multiple political equilibria — one in which the countries are both protectionist and another in which they trade freely with each other. Starting with trade protection in both countries, a unilateral reform in one country is shown to bring about a free trade equilibrium that obtains majority support in both countries.

While much of the literature has considered the merits of the two policy stances of unilateralism and reciprocity independently of each other, we focus on the possible causal connection between the two. Can unilateral trade liberalization by one country lead to reciprocal liberalization by its partner in the absence of negotiations between the two countries? In this survey paper, we consider this issue analytically in the context of different political economy approaches to trade policy determination.