Estimation of cusp location of stochastic processes: a survey

We present a review of some recent results on estimation of location parameter for several models of observations with cusp-type singularity at the change point. We suppose that the cusp-type models fit better to the real phenomena described usually by change point models. The list of models includes Gaussian, inhomogeneous Poisson, ergodic diffusion processes, time series and the classical case of i.i.d. observations. We describe the properties of the maximum likelihood and Bayes estimators under some asymptotic assumptions. The asymptotic efficiency of estimators are discussed as well and the results of some numerical simulations are presented. We provide some heuristic arguments which demonstrate the convergence of log-likelihood ratios in the models under consideration to the fractional Brownian motion.     

Applications of location models

The degree to which locational complexity and geographical complexity is represented in a location model is a critical decision that influences the quality of the application. Criteria which can be used to guide these decisions are presented and research that would better inform these decisions is described.     

Multiple criteria facility location problems: A survey

This paper provides a review on recent efforts and development in multi-criteria location problems in three categories including bi-objective, multi-objective and multi-attribute problems and their solution methods. Also, it provides an overview on various criteria used. While there are a few chapters or sections in different location books related to this topic, we have not seen any comprehensive review papers or book chapter that can cover it. We believe this paper can be used as a complementary and updated version.     

Panel data analysis: a survey on model-based clustering of time series

Clustering is a widely used statistical tool to determine subsets in a given data set. Frequently used clustering methods are mostly based on distance measures and cannot easily be extended to cluster time series within a panel or a longitudinal data set. The paper reviews recently suggested approaches to model-based clustering of panel or longitudinal data based on finite mixture models. Several approaches are considered that are suitable both for continuous and for categorical time series observations. Bayesian estimation through Markov chain Monte Carlo methods is described in detail and various criteria to select the number of clusters are reviewed. An application to a panel of marijuana use among teenagers serves as an illustration.     

A qualitative mathematical analysis of a class of nonlinear differential equations: Applications in biochemistry

In this paper, we develop a mathematical approach which can be used to display, in a systematic, rigorous and efficient way, various qualitative properties of a large class of dynamical and quasi-steady biochemical models. The applicability of the methodology has been examined for various biochemical reactions, enzyme kinetics and multi enzyme systems.     

The Quintile Share Ratio in location analysis

The inequality measure “Quintile Share Ratio” (QSR or sometimes S80/S20) is the primary income inequality measure in the European Union’s set of indicators on social cohesion. An important reason for its adoption as a leading indicator is its simplicity. The Quintile Share Ratio is “The ratio of total income received by the 20% of the population with the highest income (top quintile) to that received by the 20% of the population with the lowest income (lowest quintile)”. The QSR concept is used in this paper in the context of obnoxious facility location where the inequality is in distances to the obnoxious facility. The single facility location problem minimizing the QSR is investigated. The problem is investigated for continuous uniform demand in an area such as a disk, a rectangle, and a line; when demand is generated at a finite set of demand points; and when the facility can be located anywhere on a network. Optimal solution algorithms are devised for demand originating at a finite set of demand points and at nodes of the network. Computational experiments demonstrate the effectiveness of the algorithms.     

Travel time analysis for general item location assignment in a rectangular warehouse

A travel time model with general item location assignment in a rectangular warehouse system is presented. We give the exact probability mass functions that characterise the tour of an order picker and derive the first and second moments associated with the tour. We apply the model to analysing order batching and storage allocation strategies in an order picking system. The order picking system is modelled as a queueing system with customer batching. The results are compared and validated via simulation. The effects of batching and batch size on the delay time are discussed with consideration to the picking and sorting times for each batch of orders.     

Multicriteria analysis: survey and new directions

Before the advent of multicriteria analysis, decision problems often took the form of the optimization of an objective function or a utility function. This approach has the advantage of resulting in well-defined mathematical problems but is not always representative of reality: in fact the comparison of several possible decisions is rarely made according to a single point of view and the preferences on a point of view are in many cases only modelled with difficulty by a function. The aim of this paper is to survey the different directions in which multicriteria analysis has developed: multiattribute utility theory, outranking relations, interactive methods. The methodology recently proposed by B. Roy is also presented.     

Sensitivity analysis of a continuous multifacility competitive location and design problem

A continuous location problem in which a firm wants to set up two or more new facilities in a competitive environment is considered. Other facilities offering the same product or service already exist in the area. Both the locations and the qualities of the new facilities are to be found so as to maximize the profit obtained by the firm. This is a global optimization problem, with many parameters to be estimated, and whose behavior is not really well understood. Using random problems and a robust evolutionary algorithm recently proposed for solving this problem, the behavior of optimal solutions in various environments and changes in the basic model parameters are researched. These comprise the quality of existing and new facilities, cost function and presence of the chain. Some economic implications are derived.     

Probabilistic analysis of geometric location problems

We analyze the behaviour of thek center and median problems forn points randomly distributed in an arbitrary regionA ofR ^d . Under a mild assumption on the regionA, we show that fork≦k(n)=o(n/logn), the objective function values of the discrete and continuous versions of these problems are equal to each otheralmost surely. For the two-dimensional case, both these problems can be solved by placing the centers or medians in an especially simple regular hexagonal pattern (the ‘honeycomb heuristic’ of Papadimitriou). This yields the exact asymptotic values for thek center and median problem, namely, α(|A|/k)^1/2 and β(|A|/k)^1/2, where |A| denotes the volume ofA, α and β are known constants, and the objective of the median problem is given in terms of the average, rather than the usual total, distance. For the 3- and 4-dimensional case, similar results can be obtained for the center problem to within an accuracy of roughly one percent. As a by-product, we also get asymptotically optimal algorithms for the 2-dimensionalp-normk median problem and for the twin problems of minimizing the maximum number of vertices served by any center and similarly for maximizing the minimum.     

Obnoxious-facility location and data-envelopment analysis: A combined distance-based formulation

We have broadened the classic anti-center models to include generalized-distance measures. It includes in the inherent proximity measures other cost/benefit metrics. Unlike classic data envelopment analysis (DEA), the combined location/DEA model proposed here assumes disposability of input/output's only. It represents a more flexible formulation. The locations of multiple sites are analyzed using a binary integer program, while evaluation is performed by the full strength of a DEA model. Through a case study, we show how location and DEA models can be used together to more realistically characterize a siting decision.     

Online algorithms: a survey

 During the last 15 years online algorithms have received considerable research interest. In this survey we give an introduction to the competitive analysis of online algorithms and present important results. We study interesting application areas and identify open problems. Received: December 1, 2002 / Accepted: April 28, 2003 Published online: May 28, 2003 Mathematics Subject Classification (1991): 68W25, 68W40     

Essential dimension: a survey

In the paper we survey research on the essential dimension. The highlights of the survey are the computations of the essential dimensions of finite groups, groups of multiplicative type and the spinor groups. We present self-contained proofs of these cases and give applications in the theory of simple algebras and quadratic forms.     

A system-theoretic framework for a wide class of systems I: Applications to numerical analysis

A system-theoretic framework is proposed, which allows the study of hybrid uncertain systems, which do not satisfy the so-called “semigroup property.” Characterizations of the notion of robust global asymptotic output stability (RGAOS) are given. Based on the provided characterizations, the qualitative behavior of hybrid systems obtained by time-discretization of systems of ordinary differential equations with a globally asymptotically stable equilibrium point, is studied.     

Statistical analysis of steady-state simulations: survey of recent progress

For non-terminating simulations with steady-state responses the following alternative analysis techniques are evaluated: (i) replicated runs (ii) approximately independent subruns or batches (iii) renewal or regenerative analysis. Two general techniques for reducing nonnormality and bias are presented: grouping (or batching) and jackknifing. Applications of the various techniques are discussed. Besides the estimation of the mean, the estimation of variances and quantiles is presented.     

设施选址博弈问题的无支付机制设计研究

选址博弈是目前国际相关学术领域的重要前沿课题之一. 在选址博弈问题中, 存在n个相互影响的``理性"居民, 他们的住址等信息是其私有信息;设计者需要设计选址机制, 以居民汇报的住址信息为输入, 输出设施位置. 在进行机制设计的过程中, 如何在没有金钱的刺激下, 保证所有居民``说真话", 设计出防策略性无支付机制是其中的重要研究内容. 设施选址博弈问题的无支付机制设计是组合优化和理论计算机科学的交叉学科课题, 在管理科学、信息科学以及社会经济学等领域有着重要的应用, 具有重要的理论意义和实际的应用价值. 现根据不同设施类型及个数、不同个人偏好、不同度量空间以及不同社会总体目标等条件, 介绍各种类型的设施选址博弈模型, 罗列相关的研究成果, 并总结其中尚待解决的问题.     

Dynamic programming in sport: a survey of applications

This paper surveys applications of dynamic programming to decisionproblems faced by active participants in sports.