Preference expression and misrepresentation in points voting schemes

In a large electorate it is natural to consider voters’ preference profiles as frequency distributions over the set of all possible preferences. We assume coherence in voters’ preferences resulting in accumulation of voters preferences. We show that such distributions can be studied via superpositions of simpler so called unimodal distributions. At these, it is shown that all well-known rules choose the mode as the outcome. We provide a set of sufficient conditions for a rule to have this trait of choosing the mode under unimodal distributions. Further we show that Condorcet consistent rules, Borda rule, plurality rule are robust under tail-perturbations of unimodal distributions.

Mas-Colell and Sonnenschein [1972] have proved a well-known impossibility theorem for acyclic social preference. They showed that if social preference is acyclic for each configuration of individual preferences, and if the mapping between individual and social preferences satisfies the Pareto axiom, the independence of irrelevant alternatives, and May’s positive responsiveness axiom, then there must be an individual i such that for any x and y, xP_iy ⇒ xRy. This individual might be considered a “vetoer.”

A Sophisticated Social Welfare Function (SSWF) is a mapping from profiles of individual preferences into a sophisticated preference which is a pairwise weighted comparison of alternatives. We characterize Pareto optimal and pairwise independent SSWFs in terms of oligarchies that are induced by some power distribution in the society. This is a fairly large class ranging from dictatoriality to anonymous aggregation rules. Our results generalize the impossibility theorem of Arrow (Social choice and individual values. Wiley, New York, 1951) and the oligarchy theorem of Gibbard (Intransitive social indifference and the Arrow dilemma, University of Chicago, unpublished manuscript, 1969).

An institution is viewed as an arrangement of the society through which various social states emerge as outcomes from the actions and interactions of individuals belonging to the society. Following an earlier contribution by Pattanaik and Suzumura (Oxford Economic Papers 48:194–212, 1996), we subscribe to the view that the ethical desirability of an institution is based on the goodness of the outcomes emerging from individuals’ actions and interactions via the institution as well as the intrinsic attractiveness of the institution itself. In this paper, we explore the structure of an individual’s ethical evaluations of institutions. For this purpose, we discuss how social choices are made through institutions given profiles of individual preferences over social states, propose several a priori properties of institutions and examine their plausibility, and introduce and discuss a lexicographic maximin rule for evaluating institutions ethically.

This paper is concerned with the organization and retrieval of reusable software components with the aid of unsupervised learning. The methods considered of unsupervised learning include FUZZY ISODATA and Kohonen self-organizing maps. The key issues addressed in the study include information retrieval in the presence of incomplete information, and domain specific enhancements of unsupervised learning, including those of partial supervision. The primary intention is to reveal how the learning mechanism can accommodate individual preferences (profile) of the users viewed as a significant component of organization and retrieval algorithms. Numerical examples use a set of MS-DOS system commands and a collection of reusable C++ classes. © 1997 by John Wiley & Sons, Ltd.

I t has been demonstrated (Toman, 1962) that enduring social relationships such as friendship or marriage tend to have better chances of happiness and success, other things being equal, the closer the partners duplicate for one another the sibling relationships of their original families. Thus, an oldest brother of sisters married to the youngest sister of brothers, o r a youngest brother of sisters married to the oldest sister of brothers, would tend to fare well with his partner. However, conflict would prevail in a marriage of an oldest brother of brothers to an older sister of sisters, or of a youngest brother of brothers to a youngest sister of sisters. Both partners would try in vain to lead the partner in the first case, to find leadership with the partner in the second case. The partners of both cases are not used to living together with a peer of the opposite sex. Other determinants (social status, wealth, physique, health, etc.) may interact with this trend. The present study explored the effect of the chronological age difference between spouses for determinants of sibling position. It was expected that marriage partners who had both been oldest siblings in their original families would tend to show rank conflicts with one another. However, one spouse's being older than the other might serve to micigate the conflict. A similar relationship would hold for partners each of whom had been the youngest sibling in his original family. Larger than usual age differences might help such partners get along. If this reasoning were correct, we would expect, among other things, to find a greater than usual relative frequency of rank conflict and, possibly, of sexual conflict, defined merely by compatibility of sibling positions between marital partners of very disparate ages. The large age difference may make it less necessary for the partners to choose optimally by the criterion of sibling position alone. Also, those persons choosing partners who would be incompatible by sibling position would tend to make up for it by choosing someone much older or younger. The family constellations of 1 8 couples with unusually large age differences (12 years or more) were studied. In 15 cases the husband was the older partner, in 3 the wife. In 4 and 1 cases, respectively ( 2 8 % ) , both partners duplicated for one another sibling relationships of their original families. Generally speaking, this would mean that a husband would have had at leasc one younger sister among his siblings if his wife has had at least one older brother among her siblings, o r that the husband would have at least one older sister among his siblings if his wife has had at least one younger brother among her siblings. These frequencies compare unfavorably with 63% of such duplication found among 54 average couples, i.e., parents of college students. In 8 and 1 respectively, of the original 18 cases ( 5 0 % ) , there was a complete rank conflict, as compared with an obtained frequency of 20% for the average couples. In 6 of these 9 cases the partners had rank and sex conflicts, which is high as compared with a 15% expected incidence of such conflict among average couples.

Fundamental frequency (F0) difference limens (DLs) were measured versus F0 for sine- and random-phase harmonic complexes bandpass-filtered into low- or high-frequency regions, with 3-dB passbands of 2.5–3.5 and 5–7 kHz, respectively. In all cases, F0 DLs decreased dramatically with increasing F0 as approximately the tenth harmonic appeared in the passband. Generally, F0 DLs were similar in both frequency regions for complexes with similar harmonic numbers and phase relationships. However, F0 DLs were larger in the high-frequency than the low-frequency region for random-phase complexes containing only harmonics above the tenth, suggesting a possible role for additional fine-structure information in the low-frequency region. The dependence of F0 discrimination on relative frequency presents a significant challenge to autocorrelation (AC) models of pitch perception, in which predictions generally depend more on absolute frequency and phase locking. To represent this relative frequency effect, a ‘‘lag window’’ modification to the Meddis and O’Mard [J. Acoust. Soc. Am. 102, 1811–1820 (1997)] AC model was introduced, restricting each channel’s AC representation to a limited range of lags relative to the center frequency (CF). Thus in each channel, the AC model responds best to F0’s whose dominant harmonics fall near the CF. [Work supported by NIH Grant Nos. 5T32-DC-00038 and R01-DC-05216.]

With the rapid development of the tourist industry, an increasing number of passengers book flight tickets through online travel agencies. When searching for a flight ticket online, users are overwhelmed by the choice on offer. Even though flight ticket recommendation has been widely investigated, the current approaches are unable to recommend flight tickets that meet an individual's preference efficiently because of the severe cold-start problem. This paper provides strategies to address the cold-start problem for flight ticket recommendation. We conduct an exploratory study over the real-world flight ticket recommendation scenario and classify the cold-start problem of flight ticket recommendation into two categories, namely route cold-start and user cold-start. We propose methods based on route similarity and social relationships between passengers to improve user models. Finally, we map an enhanced user preference model and flight features to latent factor spaces to generate the recommendation results. The experimental results on a real-world data set demonstrate the effectiveness of the proposed approaches.

The matching of prosthetic devices to the needs of the individual is a challenge for providers and patients. The aims of this study are to explore the values and preferences that prosthetic users have of their prosthetic devices; to investigate users' perceptions of alternative prosthetic options and to demonstrate a novel method for exploring the values and preferences of prosthetic users. This study describes four case studies of upper limb and lower limb high tech and conventional prosthetic users. Participants were interviewed using the repertory grid technique (RGT), a qualitative technique to explore individual values and preferences regarding specific choices and events. The participants generated distinctive patterns of personal constructs and ratings regarding prosthetic use and different prosthetic options available. The RGT produced a unique profile of preferences regarding prosthetic technologies for each participant. User choice is an important factor when matching prosthetic technology to the user. The consumer's values regarding different prosthetic options are likely to be a critical factor in prosthetic acceptance and ultimate quality of life. The RGT offers a structured method of exploring these attitudes and values without imposing researcher or practitioner bias and identifies personalized dimensions for providers and users to evaluate the individuals' preferences in prosthetic technology.

This study has proposed a methodology by enhancing an interactive algorithm to multi-objective optimization problems with interval parameters, in an attempt to reach the tradeoff between quality and reliability of the resultant optimum solutions. The earlier algorithm could turn into a prolonged procedure that deals with several players with different aspirations at different reliability, or risk, levels under non-deterministic conditions. Hence, it is not a pertinent approach to solve problems of water allocation between competing parties. The enhanced methodology aims to alleviate the burdens of the procedure and generate a unique set of solutions (i.e., near-Pareto-optimal alternatives), instead of a myriad of compromise solution sets. We have investigated a real-world hydro-environmental problem, the allocation of water between Dorudzan-Korbal irrigation networks and Bakhtegan Lake in Fars Province, Iran to assess feasibility of this methodology. In order to reach a consensus concerning the stakeholders’ individual preferences, we identified the compromise alternatives from the obtained sets of non-dominated solutions by taking advantage of various social choice rules and the Nash bargaining model. The results demonstrated that the developed methodology could incorporate the risk of system constraints violations (i.e., planning reliability under uncertainty) into the process of approximating the optimal tradeoff set of solutions. It also gave policymakers a chance to acquire perception into the potentially best compromise for land and water allocation schemes regarding the preference profiles of the involved interest groups.

A new visualization-based multi-criteria procedure for group decision screening is presented. The procedure supports a group in selecting a small number of alternatives from an initial list described by a collection of attributes which are used as screening criteria. We propose and experimentally study the Group Remote Asynchronous Screening Support (GRASS) procedure that can be used by a large number of participants who are not able to meet face to face. GRASS does not use any interaction between the participants and the group screening is based on the individual preferences expressed by them independently from each other. GRASS uses the concepts of Borda count, by applying the visualization of information to simplify the analysis of large lists of multi-criteria alternatives. Visualization is used to support the individual analysis of the variety of alternatives and the individual selecting of a small number of alternatives from the list for the subsequent scoring through Borda count. Visualization is carried via the Interactive Decision Maps / Reasonable Goals Method (IDM/RGM) technique. We first check a speculative supposition that participants are able to find a single best alternative by using the GRASS procedure. As it is not the case, we re-formulate our hypothesis and check whether the most preferred alternative is part of a short list of alternatives returned through GRASS. The experiment was carried out with senior applied mathematics students who managed to apply GRASS without any problem.

Background: The usefulness of inflammatory indices in assessment of the severity of acute diverticulitis remains unestablished. The aim of this study was to determine whether inflammatory indices and hematological ratios could be utilised to differentiate between uncomplicated and complicated diverticulitis. Methods: Hematological and inflammatory indices were recorded for each admission with CT confirmed acute diverticulitis (101 complicated, 127 uncomplicated). Cases were divided into training (n = 57) and test sets (n = 171). A classification and regression tree (CART) analysis was employed in the training set to identify optimal inflammatory marker cut-off points associated with complicated diverticulitis. Samples (test set) were then categorized as (A) greater than and (B) less than CART identified cut-off points. The predictive properties of inflammatory marker cut-off points in distinguishing severity of diverticulitis were assessed using a univariate logistic regression analysis, summary receiver operating characteristic curves and confusion matrix generation. Results: C-reactive protein >109 mg/ml (OR 3.07, 95% CI 1.43-6.61, p = 0.004, area under the curve; AUC = 0.64) and white cell lymphocyte ratio (WLR) >17.72 (OR 4.23, 95% CI 1.95-9.17, p < 0.001, AUC = 0.64) were the most accurate parameters in distinguishing complicated and uncomplicated disease. WCC >21 × 10⁹/l (p = 0.02, AUC = 0.60) and lymphocyte count >0.55 × 10⁹/l (p = 0.009, AUC = 0.60) were less accurate. Conclusion: Widely used inflammatory indices are useful in the depiction of complicated diverticulitis. The indices cut-off points highlighted in this study should be considered at the time of diagnosis in combination with radiological features of complicated diverticulitis.

Stable voting schemes

The Probability of Condorcet Cycles and Super Majority Rules

This paper deals with a problem on the learning characteristics of human operator in a compensatory tracking control task.It is already known that the human operator can learn and adapt himself to changes in control dynamics.It is therefore essential for a system designer to analyze the learning behavior of the human operator. However, the process of learning has not been nivestigated in much detail. A new method to assess the learning process of a human operator is proposed here by fitting the experimental curve to logarithmic function. Variations of the coefficients are then considered to provide a measure for the learning speed.The new method of evaluating the learning process is applied to the cases of step response and frequency response. Also, in order to reduce the training interval, the method of performance scores display is used for the detection of optimal switching point in a relay control system. The result of these investigations presented in this paper are expected to be of use in the design of man-machine systems.