Showing papers on "Matching (statistics) published in 1990"

Two-Sided Matching: A Study in Game-Theoretic Modeling and Analysis

Abstract: Foreword Robert Auman Acknowledgment 1. Introduction Part I. One-To-One Matching: the Marriage Model: 2. Stable matchings 3. The structure of the set of stable matchings 4. Strategic questions Part II. Many-To-One Matching: Models in which Firms May Employ Many Workers: 5. The college admissions model and the labor market for medical interns 6. Discrete models with money, and more complex preferences Part III. Models of One-To-One Matching with Money as a Continuous Variable: 7. A simple model of one seller and many buyers 8. The assignment game 9. The generalization of the assignment model Part IV. Epilogue: 10. Open questions and research directions Bibliography Indexes.

Two-Sided Matching

Abstract: Two-sided matching provides a model of search processes such as those between firms and workers in labor markets or between buyers and sellers in auctions. This book gives a comprehensive account of recent results concerning the game-theoretic analysis of two-sided matching. The focus of the book is on the stability of outcomes, on the incentives that different rules of organization give to agents, and on the constraints that these incentives impose on the ways such markets can be organized. The results for this wide range of related models and matching situations help clarify which conclusions depend on particular modeling assumptions and market conditions, and which are robust over a wide range of conditions.

Automatic call distribution based on matching required skills with agents skills

Abstract: Automatic Call Distribution (ACD) equipment is improved by matching the information needs of an incoming caller with the particular expertise of a telemarketing agent who handles such calls. Each incoming call is assigned up to three prioritized skill numbers that estimate skill requirements of the calling party. Each agent possesses up to four skill numbers that represent various particular abilities of that agent. Numbers 1 through 9 are used. Upon arrival of the incoming call, a search is made for a match between the first caller skill number and an available agent possessing that skill. If no match is found, a similar search is made with respect to the second caller skill number. After a predetermined delay, a search is made with respect to the third caller skill number. When a match is found, the incoming call is connected to the agent possessing that skill. The longer that an incoming call remains unanswered, the larger the pool of agents becomes that will be allowed to handle the call. Although the specific expertise sought may not be matched, the present technique optimizes the matching process when a time constraint is imposed.

Random paths to stability in two-sided matching

Abstract: EMPIRICAL STUDIES OF TWO SIDED MATCHING have so far concentrated on markets in which certain kinds of market failures were addressed by resorting to centralized, deterministic matching procedures. Loosely speaking, the results of these studies are that those centralized procedures which achieved stable outcomes resolved the market failures, while those markets organized through procedures that yielded unstable outcomes continued to fail.2 So the market failures seem to be associated with instability of the outcomes. But many entry-level labor markets and other two-sided matching situations don't employ centralized matching procedures, and yet aren't observed to experience such failures. So we can conjecture that at least some of these markets may reach stable outcomes by means of decentralized decision making. And decentralized decision making in complex environments presumably introduces some randomness into what matchings are achieved. However, as far as we are aware, no nondeterministic models leading to stable outcomes have yet been studied. The present paper demonstrates that, starting from an arbitrary matching, the process of allowing randomly chosen blocking pairs to match will converge to a stable matching with probability one. (This resolves an open question raised by Knuth (1976), who showed that such a process may cycle.) Furthermore, every stable matching can arise

Generalized Deformable Models, Statistical Physics, and Matching Problems

Abstract: We describe how to formulate matching and combinatorial problems of vision and neural network theory by generalizing elastic and deformable templates models to include binary matching elements. Techniques from statistical physics, which can be interpreted as computing marginal probability distributions, are then used to analyze these models and are shown to (1) relate them to existing theories and (2) give insight into the relations between, and relative effectivenesses of, existing theories. In particular we exploit the power of statistical techniques to put global constraints on the set of allowable states of the binary matching elements. The binary elements can then be removed analytically before minimization. This is demonstrated to be preferable to existing methods of imposing such constraints by adding bias terms in the energy functions. We give applications to winner-take-all networks, correspondence for stereo and long-range motion, the traveling salesman problem, deformable template matching, learning, content addressable memories, and models of brain development. The biological plausibility of these networks is briefly discussed.

Toward memory-based translation

Abstract: An essential problem of example-based translation is how to utilize more than one translation example for translating one source sentence.This paper proposes a method to solve this problem. We introduce the representation, called matching expression, which represents the combination of fragments of translation examples. The translation process consists of three steps: (1) Make the source matching expression from the source sentence. (2) Transfer the source matching expression into the target matching expression. (3) Construct the target sentence from the target matching expression.This mechanism generates some candidates of translation. To select the best translation out of them, we define the score of a translation.

Occupational Matching: A Test of Sorts

Abstract: This paper develops a theory of job matching in which matching information has both job-specific and occupation-specific components. If occupational matching is significant, then the theory predicts that for those who have switched jobs but remained in the same occupation, increased tenure in the previous job lowers the likelihood of separation from the current job. These predictions are tested using job tenure data from the National Longitudinal Survey's youth cohort. In general, the data are consistent with the occupational matching hypothesis.

New physicians: a natural experiment in market organization

Abstract: The National Resident Matching Program is a centralized clearinghouse through which new medical graduates in the United States obtain their first positions. The history of this market, from the market failures that the centralized system was designed to address, to the present, is discussed, and a hypothesis about the behavior of such markets is presented. New evidence is then presented from a set of similar centralized markets in the United Kingdom. Because some of these latter markets have failed, while others have succeeded, they provide a natural experiment that permits the hypothesis to be tested. The new evidence also suggests directions in which modifications of existing procedures might be considered.

The matching model: An examination of the processes underlying realistic job previews.

Abstract: Using information systems and data processing personnel in 9 major insurance companies, this research assessed the validity of Wanous's (1980)matching model as a framework of the processes linking realistic job previews (RJPs) to employee adjustment and employment stability. Because the matching model is an adaptation of the Theory of Work Adjustment (TWA), this study also assessed the TWA's applicability to RJP and turnover research. Structural equation methodology tested the fit of the matching model to the data of newcomers and of more tenured employees. Also, two-group structural analysis was performed to determine differences between groups. Support for the matching model was obtained with newcomer data but not with data from tenured employees. Results also supported the applicability of the TWA to RJP and turnover research. Implications of the findings to work adjustment and RJP research are discussed.

Record Linkage: Statistical Models for Matching Computer Records

Abstract: We wish to measure the evidence that a pair of records relates to the same rather than different individuals. The paper emphasizes statistical models which can be fitted to a file of record pairs known to be correctly matched and then used to estimate likelihood ratios. A number of models are developed and applied to U.K. immigration statistics. The combination of likelihood ratios for possibly correlated record fields is discussed. A series of comments on the paper is also included as well as a reply to those comments by the author (pp. 312-20). (EXCERPT)

The use of picture/word matching tasks to assist word retrieval in aphasic patients

Abstract: Three single case studies and a small group study were undertaken to examine the effects of using picture to word matching tasks as a therapeutic technique in aiding word retrieval in aphasic patie...

On the performance of lazy matching in production systems

Abstract: Production systems are an established method for encoding knowledge in an expert system. The semantics of production system languages and the concomitant algorithms for their evaluation, RETE and TREAT, enumerate the set of rule instantiations and then apply a strategy that selects a single instantiation for firing. Often rule instantiations are calculated and never fired. In a sense, the time and space required to eagerly compute these unfired instantiations is wasted. This paper presents preliminary results about a new match technique, lazy matching. The lazy match algorithm folds the selection strategy into the search for instantiations, such that only one instantiation is computed per cycle. The algorithm improves the worst-case asymptotic space complexity of incremental matching. Moreover, empirical and analytic results demonstrate that lazy matching can substantially improve the execution time of production system programs.

A Collateral Effect of Reward Predicted By Matching Theory

Abstract: Matching theory describes a process by which organisms distribute their behavior between two or more concurrent schedules of reinforcement (Herrnstein, 1961). In an attempt to determine the generality of matching theory to applied settings, 2 students receiving special education were provided with academic response alternatives. Using a combined simultaneous treatments design and reversal design, unequal ratio schedules of reinforcement were varied across two academic responses. Findings indicated that both subjects allocated higher rates of responses to the richer schedule of reinforcement, although only one responded exclusively to the richer schedule. The present results lend support to a postulation that positive reinforcement may have undesirable collateral effects that are predicted by matching theory (Balsam & Bondy, 1983).

Matching and efficiency in cohort studies

Abstract: Contrary to the impression given in some textbooks, matching can reduce the efficiency of a cohort study, even when it produces no sample-size reduction and even if the matching variable is a confounder. The authors illustrate this along with some additional points regarding cohort matching. First, the impact of matching on efficiency can be in opposite directions for different measures of effect; as a consequence, criteria for deciding whether to match must depend on whether one wishes to estimate relative or absolute effects. Second, the commonly drawn analogy between blocking in randomized trials and matching in cohort studies is misleading when one considers the impact of matching on covariate distributions. Third, the conditions for efficiency overmatching in a cohort study are different from the conditions in a case-control study. It appears that, under an additive model, matching will usually increase the efficiency of both risk-difference and risk-ratio estimation, and the power of the Mantel-Haenszel test. Under a multiplicative model, the impact of matching is not as consistently beneficial. The authors present some approximate criteria which allow one to use a priori information to predict whether cohort matching is likely to improve efficiency.

Analogy for Automated Reasoning

Abstract: What is analogy? heuristics for analogy matching flexible matching plan construction plan application learning global analogies.

Optimum load matching in direct-coupled photovoltaic power systems-application to resistive loads

Abstract: The load matching factor is used as a measure for the quality of load matching to a photovoltaic (PV) array. An optimization approach is used to solve the load matching problem with the objective of maximizing the load matching factor, and consequently the PV output energy. This approach is then applied to resistive loads (with and without an internal EMF) connected to the array. Results show that optimum matching can be achieved by carefully selecting the array parameters with respect to the load parameters. The temperature of the array has little effect on the optimum matching factor. However, the optimum matching parameters are greatly affected by the array temperature. A maximum power tracker may not be achieved. >

Stereo by incremental matching of contours

Abstract: Contours made of sequences of adjacent edge points are used as primitives in stereo pair matching. Matching contour segments, rather than the traditional epipolar edge points, can greatly reduce possible ambiguity. This is done by reformulating point-matching constraints to apply to contour matching, and by introducing a unique incremental matching scheme. Best-matched contours are paired first, constraining through neighborhood support their neighboring contours. Examples of the proposed stereo matching scheme are shown, with very few errors, for aerial images of natural terrain. >

Assessing the gain in efficiency due to matching in a community intervention study

Abstract: COMMIT (Community Intervention Trial for Smoking Cessation) is a randomized study employing a matched pairs design Pairs of communities were selected on the basis of their geographical proximity and were chosen to be matched on variables strongly expected to relate to the outcome variable, the smoking quit rate However, quantitative information was not available to evaluate the efficiency gain from matching We have used baseline smoking quit rates in the communities as a surrogate for the outcome measure to evaluate the gain in efficiency from the matching Our method takes account of the possible imperfection of the surrogate as a representative of the true outcome The method estimates an efficiency gain of at least 50 per cent using the matched design We also evaluate the further gains in efficiency which would be made by using the baseline quit rate to balance the randomization

On the possible psychophysical laws revisited: remarks on cross-modal matching

Abstract: A nonrelational theory of cross-modal matching, including magnitude estimation, is proposed for the general class of 1-dimensional measurement structures that have real-unit (ratio and interval scale) representations

A theory of image matching

Abstract: A theoretical framework is presented in which windowed Fourier phase (WFP) is introduced as the primary matching primitive. Zero-crossings and peaks correspond to special values in the phase profile. The WFP is quasi-linear, dense and its spatial period and slope are controlled by the channel scale. This framework has the following important characteristics: matching primitives are available almost everywhere to convey dense disparity information in every channel, either coarse or fine; the false target problem is virtually eliminated; matching is easier, uniform and can be performed by a network suitable for parallel computer architecture; and matching is fast since very few iterations are needed. In fact, the WFP is so informative that the original signal can be uniquely determined up to a multiplicative constant by the WFP in any one channel. The use of phase as the matching primitive is also supported by some existing psychophysical and neurophysiological studies. An implementation of the proposed theory has shown good results from images of random dots and natural scenes. >

A maximum stable matching for the roommates problem

Abstract: The stable roommates problem is that of matchingn people inton/2 disjoint pairs so that no two persons, who are not paired together, both prefer each other to their respective mates under the matching. Such a matching is called “a complete stable matching”. It is known that a complete stable matching may not exist. Irving proposed anO(n 2) algorithm that would find one complete stable matching if there is one, or would report that none exists. Since there may not exist any complete stable matching, it is natural to consider the problem of finding a maximum stable matching, i.e., a maximum number of disjoint pairs of persons such that these pairs are stable among themselves. In this paper, we present anO(n 2) algorithm, which is a modified version of Irving's algorithm, that finds a maximum stable matching.

Species-for-Species Matching

Abstract: Few patterns in nature are more spectacular than species-for-species matching, whereby independent, ecologically equivalent sets of species are found in similar habitats at different locations (Cody 1974; Ricklefs and Travis 1980). For example, Brown (1975) noted similarity between the Great Basin and Sonoran deserts in the body-size distributions ofrodent species. Heatwole and Levins (1972) observed relative constancy in the number of arthropod species in different trophic lasses among mangrove islands defaunated by Simberloff and Wilson (1969). They also noted constancy between the arthropod assemblages of a given island before defaunation and after recolonization. In the rodent example, sets of species in different communities appear to be matched by a continuous variable (body size), whereas matching between sets of mangrove arthropods is by discrete trophic category. Identifying matching is not trivial, since in virtually all putative cases the correspondence between communities i imperfect. The number of species is rarely identical in different communities, and species present in one community often lack a counterpart inthe other. Procedures are thus required to help indicate trends when a precise match is unrealized. Ricklefs and Travis (1980) suggested a criterion for matching that is based on the relative similarities of individual species within and between communities. Their solution is most useful when the number of species is the same in each community and when matching occurs with respect to a continuous variable. Here I suggest a more general criterion for matching and demonstrate its use. I also consider the implications of matching for the presence of certain interspecific interactions. Finally, I discuss why matching might be infrequent innature ven if convergence between communities i common.

Data Structures for Weighted Matching and Nearest Common Ancestors with Linking ; CU-CS-478-90

Abstract: This paper shows that the weighted matching problem on general graphs can be solved in time O(n(m + n log n)), f or n and m the number of vertices and edges, respectively. This was previously known only for bipartite graphs. It also shows that a sequence of m nca and link operations on n nodes can be processed on-line in time O(ma(m, n)+n). This was previously known only for a restricted type of link operation.