Behavior in Repeated Prisoner's Dilemma Games with Shifted Outcomes Analyzed with a Statistical Learning Model

A fuzzy set theoretical framework is proposed for the analysis of sociometric structure characterized by vagueness of liking between individuals and a person's relative degree of belonging to a social group. Max‐min transitivity of a fuzzy relation is employed as a basic concept to examine the degree of liking and clustering in group structures. A distance model based on min‐max transitivity is also formulated as a special case of transitivity analysis. Other notions of transitivity such as the max‐product and the max‐* are also discussed. An empirical analysis is performed to examine the applicability of the proposed transitivity concepts. It appears that the current methodological construct provides a more appropriate perspective in the analysis of the group structure properties.     

Clusterwise aggregation of relations: The case of paired comparisons of cognac ads

This short paper takes up the problem stated by Gaul and Schader¹ in 1988 of simultaneous clustering and aggregation of relations—in this case precedences (preferences)—so that aggregate preferences could represent relatively homogeneous groups of preference relations. The paper indicates the existence of two distinct questions, similar to those asked in the case of the global aggregation problem, regarding intra-group agreement as to preferences represented in whatever form, and intra-group agreement as to a common (‘regular’) preference. In both these cases, though, fundamental computational problems arise. This paper presents a heuristic for obtaining an approximate solution. Requirements as to the properly optimal method are outlined.     

On fair coin-tossing games

Let Ω be a finite set with k elements and for each integer $\text{n ≧ 1}$ let $\text{Ω}{}_{\mathrm{n}}\text{= Ω × Ω × … × Ω}$ (n-tuple) and $\text{Ω}{}_{\mathrm{n}}\text{= {(a}{}_1\text{, a}{}_2\text{,…, a}{}_{\mathrm{n}}\text{) | (a}{}_1\text{, a}{}_2\text{,…, a}{}_{\mathrm{n}}\text{) ∈ Ω}{}_{\mathrm{n}}$ and a_j ≠ a_j+1 for some 1 ≦ j ≦ n ? 1}. Let {Y_m} be a sequence of independent and identically distributed random variables such that P(Y₁ = a) = k^?1 for all a in Ω. In this paper, we obtain some very surprising and interesting results about the first occurrence of elements in $\text{Ω}{}_{\mathrm{n}}$ and in Ω?_n with respect to the stochastic process {Y_m}. The results here provide us with a better and deeper understanding of the fair coin-tossing (k-sided) process.     

An upper bound for the solvability probability of a random stable roommates instance

It is well-known that not all instances of the stable roommates problem admit a stable matching. Here we establish the first nontrivial upper bound on the limiting behavior of P_n, the probability that a random roommates instance of size n has a stable matching, namely, lim _n→∞ Pn? e^1/2/2 (=0.8244…). © 1994 John Wiley & Sons, Inc.     

Experiments with an interactive paired comparison simplex method for molp problems

In this paper, an interactive paired comparison simplex based method formultiple objective linear programming (MOLP) problems is developed and compared to other interactive MOLP methods. The decision maker (DM)’s utility function is assumed to be unknown, but is an additive function of his known linearized objective functions. A test for ‘utility efficiency’ for MOLP problems is developed to reduce the number of efficient extreme points generated and the number of questions posed to the DM. The notion of ‘strength of preference ’ is developed for the assessment of the DM’s unknown utility function where he can express his preference for a pair of extreme points as ‘strong ’, ‘weak ’, or ‘almost indifferent ’. The problem of ‘inconsistency of the DM’ is formalized and its resolution is discussed. An example of the method and detailed computational results comparing it with other interactive MOLP methods are presented. Several performance measures for comparative evaluations of interactive multiple objective programming methods are also discussed. All rights reserved. This study, or parts thereof, may not be reproduced in any form without written permission of the authors.     

Preferences,agreement, consensus — measuring,aggregation and control

This paper presents a model for analysis and a practical method of management of a session meant at attainment of consensus regarding preferences over a set of multi-aspect options, these preferences being expressed through pairwise comparisons or orderings. The model and the method accept and process valued or fuzzy preferences, while preserving an entirely crisp procedure throughout the approach. The aggregation method presented previously in Owsiski and Zadrony [17, 18] is referred to and expanded for the case of clusterwise preference aggregation and consensus measurement. The framework of the clustering approach of Owsiski [19] is applied, allowing for a natural definition of consensus.     

投保人异质性风险偏好下指数保险市场均衡的动态演化分析

兼具道德风险与逆向选择免疫性和即刻赔付双重优势的指数保险逐渐成为巨灾风险管理的重要工具,但目前多处于试点阶段,市场均衡演化规律仍不明确。本文构建了指数保险市场中保险公司、投保人和政府的三方演化博弈模型,同时,考虑投保人面对损失与收益的不同风险态度,引入异质性风险偏好设计了投保人决策函数,进而分析指数保险市场均衡演化路径及其影响因素。结果表明,指数保险市场均衡随其生命周期的演进而变化,政府在指数保险市场中的职能将从管理者走向退出;政府对保险公司进行补贴更有效,但补贴力度需在适度范围内。影响因素方面,投保人的异质性风险偏好对市场均衡演化有重要影响,其损失敏感性将加快市场向均衡状态的收敛速度;提前赔付优势能够促进市场向均衡状态收敛,但溢出效应会延缓均衡的达成。基于此提出了政府对指数保险市场引导与鼓励的建议。     

Conformational analysis of phorboxazole bis-oxazole oxane fragment analogs by NMR spectroscopy and molecular modeling simulations

We present a detailed conformational study of a simplified synthetic analog of the bis-oxazole oxane fragment found in the cytostatic agents phorboxazole A and B based on results from NMR spectroscopy and molecular modeling simulations. Complete 1H and 13C resonance assignments for the bis-oxazole oxane system were carried out through the use of COSY, HSQC, HMBC, TOCSY, and HSQC-TOCSY experiments, and its conformational preferences in solution were investigated by analysis of 3J(HH) coupling constants and NOE enhancements obtained from 1D and 2D NOESY experiments. In order to solve inconsistencies from our preliminary structural studies, simulated annealing studies were performed to thoroughly sample the phase space available to the molecule. Our results reveal that the six-membered oxane ring, which constitutes the most important moiety regarding the three-dimensional (3D) structure and flexibility of the analog, exists in rapid equilibrium between its two accessible chair conformers in an approximate ratio of 70:30. The information gathered from these studies will be of critical importance in our efforts to prepare novel compounds with phorboxazole-like structure and activity.     

均值方差偏好和期望损失风险约束下的动态投资组合

本文在均值方差框架下,研究了期望损失风险约束下的连续时间动态投资组合问题。运用鞅理论和凸对偶方法,分别给出了最优财富和最优投资策略的解析式,而且两基金分离定理仍然成立。最后通过数值例子分析了风险约束对最优投资策略的影响。     

The preferences of orientations between the pairs of amino acids

In this work, we make an investigation on the preferences of orientations between amino acids using the orientation defined based on the local geometry of the amino acids concerned. It is found that there are common preferences of orientations (70°, 30°}, 140°) and (110°, 340^{\circ}, 100°) for various pairs of amino acids. Different side chains may strengthen or weaken the common preferences, which is related to the effect of packing. Some amino acids having specific local flexibility may possess some preferences of orientations besides the common ones, such as (10°, 280°, 210°). Another analysis on the pairs of the amino acids with different secondary-structure preferences shows that the directional interaction may affect the distribution of orientation more effectively than the packing or local flexibility. All these results provide us some insight of the organization of amino acids in protein, and their relation with some related interactions.