Modeling the winning seed distribution of the NCAA Division I men׳s basketball tournament

The National Collegiate Athletic Association׳s (NCAA) men׳s Division I college basketball tournament is an annual competition that draws widespread attention in the United States. Predicting the winner of each game is a popular activity undertaken by numerous websites, fans, and more recently, academic researchers. This paper analyzes the 29 tournaments from 1985 to 2013, and presents two models to capture the winning seed distribution (i.e., a probability distribution modeling the winners of each round). The Exponential Model uses the exponential random variable to model the waiting time between a seed׳s successive winnings in a round. The Markov Model uses Markov chains to estimate the winning seed distributions by considering a seed׳s total number of winnings in previous tournaments. The proposed models allow one to estimate the likelihoods of different seed combinations by applying the estimated winning seed distributions, which accurately summarize aggregate performance of the seeds. Moreover, the proposed models show that the winning rate of seeds is not a monotonically decreasing function of the seed number. Results of the proposed models are validated using a chi-squared goodness of fit test and compared to the frequency of observed events.     

风险投资的地理亲近：对中国风险投资的实证研究

风险投资的地理亲近是指风险投资机构倾向于投资其所在地周边的企业。利用CVSource数据库,搜集2010年至2012年623家风险投资机构对1 020家企业的2 973轮风险投资交易事件信息,采用1：1配伍设计,运用STATA进行relogit回归分析,研究空间距离对投资交易达成可能性的影响。研究结果表明,随着两地空间距离的增加,风险投资交易达成的可能性降低,投资金额对空间距离与投资发生可能性之间关系起倒U形的调节作用,风险投资机构的经验调节二者之间的反向作用,经验丰富的风险投资机构不很在意目标企业的位置,其经验可以在某种程度上消除距离带来的不利影响。     

An exact approach for the balanced <Emphasis Type="Italic">k</Emphasis>-way partitioning problem with weight constraints and its application to sports team realignment

In this work a balanced k-way partitioning problem with weight constraints is defined to model the sports team realignment. Sports teams must be partitioned into a fixed number of groups according to some regulations, where the total distance of the road trips that all teams must travel to play a double round robin tournament in each group is minimized. Two integer programming formulations for this problem are introduced, and the validity of three families of inequalities associated to the polytope of these formulations is proved. The performance of a tabu search procedure and a branch and cut algorithm, which uses the valid inequalities as cuts, is evaluated over simulated and real-world instances. In particular, an optimal solution for the realignment of the Ecuadorian football league is reported and the methodology can be suitable adapted for the realignment of other sports leagues.     

IT服务外包项目工期与费用控制的 多属性英氏逆拍卖机制

工期和费用是影响IT服务外包项目成败的两个重要因素,且两者之间呈负相关的关系。在IT服务外包项目执行前,发包方与接包方需要就项目的工期和费用达成一致。通常,发包方并不完全了解外包项目的市场行情,在这种情况下,就需要一种有效的方式使发包方和接包方之间就工期和费用达成一致。本文设计了改进的英氏逆拍卖机制,针对一对多的情况设计了新的拍卖协议;针对工期和费用的多属性情况,引入多属性效用理论解决,设计了相应的效用增加函数。最后通过一个算例来演示所设计的拍卖机制对解决此类决策问题的作用。得出一些结论:所设计机制能够以拍卖方式描述费用和工期管理流程;找到了发包方和接包方的最佳增量效用,并且建议的拍卖协议是发包方和接包方获得双赢结果的机制;从不同大小的案例中可以得到完全一致的结果,这表明设计的拍卖机制的有效性和效用增加函数对协商结果的有效性。     

Supply Chain Models with Mutual Commitments and Implications for Social Responsibility

In today's increasingly globalized environment, more and more companies recognize the mutual dependence of supply chain partners in value creation. When making business decisions, they take into consideration their partners’ bottom line profitability, especially in emerging markets. The question is, is this kind of practice sustainable? This study makes an attempt to formalize this issue by examining a stylized two‐party supply chain model in which each player maximizes its own profit while making a certain commitment to its partner. We compare five different games between the two supply‐chain partners, which reflect different power positions of the players and different levels of commitment. We identify conditions under which both players are better off with mutual commitments than without, a situation we call win–win. We show that win–win can be achieved if and only if the mutual commitments are comparable. Thus, the recognition of mutual dependence of the supply chain members needs to be translated into reciprocal concerns. In addition, different players’ commitments play different roles but together they have a similar effect as a profit sharing contract. Finally, we discuss the implications of our findings in the context of socially responsible operations. In particular, our analyses show that it is possible to care about the supply chain partners’ bottom line without sacrificing one's own profitability, and our models can be used as a tool to determine the commitment levels by evaluating the predicted outcome.     

Improved Methods for Estimating Flood Depth Exceedances Within Storm Surge Protection Systems

Contemporary studies conducted by the U.S. Army Corps of Engineers estimate probability distributions of flooding on the interior of ring levee systems by estimating surge exceedances at points along levee system boundaries, calculating overtopping volumes generated by this surface, then passing the resulting volumes of water through a drainage model to calculate interior flood depths. This approach may not accurately represent the exceedance probability of flood depths within the system interior; a storm producing 100‐year surge at one point is unlikely to simultaneously produce 100‐year surge levels everywhere around the system exterior. A conceptually preferred approach estimates surge and waves associated with a large set of storms. Each storm is run through the interior model separately, and the resulting flood depths are weighted by a parameterized likelihood of each synthetic storm. This results in an empirical distribution of flood depths accounting for geospatial variation in any individual storm's characteristics. This method can also better account for the probability of levee breaches or other system failures. The two methods can produce different estimates of flood depth exceedances and damage when applied to storm surge flooding in coastal Louisiana. Even differences in flood depth exceedances of less than 0.2 m can still produce large differences in projected damage. This article identifies and discusses differences in estimated flood depths and damage produced by each method within multiple Louisiana protection systems. The novel coupled dynamics approach represents a step toward enabling risk‐based design standards.     

Romancing leadership: Past, present, and future

This paper presents a review of the romance of leadership and the social construction of leadership theory 25 years after it was originally introduced. We trace the development of this theoretical approach from the original formulation of the romance of leadership (RoL) theory as attributional bias through its emergence as a radical, unconventional approach that views leadership as a sensemaking activity that is primarily ‘in the eye of the beholder.’ We subsequently review research published in management and organizational psychology journals, book chapters and special issues of journals from 1985 to 2010. Three overall themes emerged from this review: 1) biases in (mis)attributions of leadership, including attributions for organizational success and failure; 2) follower-centered approaches, including the role of follower characteristics, perceptions, and motivations in interpreting leadership ratings; and 3) the social construction of leadership, including interfollower and social contagion processes, the role of crisis and uncertainty, and constructions and deconstructions of leadership and CEO celebrity in the media. Within each of these themes, we examine developments and summarize key findings. Our review concludes with recommendations for future theoretical and empirical work in this area.     

Firms' R&D Cooperation Behavior in a Supply Chain

This study investigates firms' R&D cooperation behavior in a supply chain where two firms first cooperate in R&D investments and then decide the production quantity according to a wholesale price contract. By using a concept named contribution level that measures a firm's technological contribution to the R&D cooperation in the supply chain, we show that both firms can achieve win–win via cartelization only if their contribution levels are Pareto matched, i.e., when each firm's contribution level is comparable to its partner's. When spillovers are endogenized, we further establish that an increasing spillover always benefits both firms without any R&D cooperation, but only benefits the firm whose contribution level is relatively low when under R&D cartels. Finally, we show that the path of first increasing spillovers to be perfect and then forming a cartel has a higher chance of achieving the best mode in terms of profitability.     

机会公平、倾斜政策与不对称锦标赛:一项实验研究

采用实验研究的方法评价机会公平规则和倾斜政策对员工努力水平及雇主收益的影响.利用对130个被试进行的7个实验,本文获得了如下研究结论:与基准实验相比,在不公平锦标赛实验中,被试的努力水平有所降低;在不对称锦标赛实验中,随着代理人能力不对称程度逐渐增加,有利被试和不利被试选择的努力水平均会减少;在倾斜政策实验中,实施倾斜政策并没有增加员工的总产出,因而也没有提高雇主的收益.文末从企业组织和政府政策两方面分析了研究结论的实际意义.     

考虑属性关联的两阶段获胜者确定模型

研究了多属性逆向拍卖的获胜者确定问题。考虑属性之间的两两关联，以定义在2-可加模糊测度上的Choquet积分表达拍卖人的偏好，其中模糊测度的值由拍卖人提供的偏好信息推测得出。由于一般情况下与偏好信息一致的模糊测度取值并不唯一，考虑所有一致的评分函数提出了两阶段获胜者确定方法。首先采用线性规划挑选出在任意评分函数下可能获胜的报价，再通过混合整数规划确定一个与所有一致的评分函数的评价结果最为接近的报价排序，以得分最高者为稳健获胜报价。仿真实验表明，大量的报价为不可能获胜报价，说明了在第一阶段进行筛选的必要性。与现有方法的比较表明了该方法的有效性，且在拍卖轮数较大、报价数目较多时，该方法在计算效率上更有优势。     

On the Complex Quantification of Risk: Systems‐Based Perspective on Terrorism

This article highlights the complexity of the quantification of the multidimensional risk function, develops five systems‐based premises on quantifying the risk of terrorism to a threatened system, and advocates the quantification of vulnerability and resilience through the states of the system. The five premises are: (i) There exists interdependence between a specific threat to a system by terrorist networks and the states of the targeted system, as represented through the system's vulnerability, resilience, and criticality‐impact. (ii) A specific threat, its probability, its timing, the states of the targeted system, and the probability of consequences can be interdependent. (iii) The two questions in the risk assessment process: “What is the likelihood?” and “What are the consequences?” can be interdependent. (iv) Risk management policy options can reduce both the likelihood of a threat to a targeted system and the associated likelihood of consequences by changing the states (including both vulnerability and resilience) of the system. (v) The quantification of risk to a vulnerable system from a specific threat must be built on a systemic and repeatable modeling process, by recognizing that the states of the system constitute an essential step to construct quantitative metrics of the consequences based on intelligence gathering, expert evidence, and other qualitative information. The fact that the states of all systems are functions of time (among other variables) makes the time frame pivotal in each component of the process of risk assessment, management, and communication. Thus, risk to a system, caused by an initiating event (e.g., a threat) is a multidimensional function of the specific threat, its probability and time frame, the states of the system (representing vulnerability and resilience), and the probabilistic multidimensional consequences.     

The Assessment of Probability Distributions from Expert Opinions with an Application to Seismic Fragility Curves

A method is developed for estimating a probability distribution using estimates of its percentiles provided by experts. The analyst's judgment concerning the credibility of these expert opinions is quantified in the likelihood function of Bayes'Theorem. The model considers explicitly the random variability of each expert estimate, the dependencies among the estimates of each expert, the dependencies among experts, and potential systematic biases. The relation between the results of the formal methods of this paper and methods used in practice is explored. A series of sensitivity studies provides insights into the significance of the parameters of the model. The methodology is applied to the problem of estimation of seismic fragility curves (i.e., the conditional probability of equipment failure given a seismically induced stress).     

相对业绩对投资基金风险承担行为的影响研究

本文把投资基金市场视为一系列的"联赛"建立了一个博弈模型,从理论上研究了相对业绩对投资基金风险承担行为的影响。在模型中,两个年中业绩不同的基金为了在年末即"联赛"结束时获得更多新的资金流入从而获得更多的报酬而相互竞争。与人们的直觉相反,我们发现在年末时年中业绩较好的基金反而比年中业绩较差的基金更可能选择风险水平较高的投资组合。而且,年中业绩的差距越大、风险资产的收益越高、波动越低,在年末时年中业绩较好的基金选择风险较高的投资组合的概率越大;相应地,在年末时年中业绩较差的基金选择风险较高的投资组合的概率越小。最后,我们运用博弈原理和行为金融理论对这些结论作了解释。     

Competitive intensity and quality maximizing seedings in knock-out tournaments

Before a knock-out tournament starts, the participants are assigned to positions in the tournament bracket through a process known as seeding. There are many ways to seed a tournament. In this paper, we solve a discrete optimization problem of finding a seeding that maximizes spectator interest in a tournament when spectators are interested in matches with high competitive intensity (i.e., matches that involve teams comparable in strength) and high quality (i.e., matches that involve strong teams). We find a solution to the problem under two assumptions: the objective function is linear in quality and competitive intensity and a stronger team beats a weaker one with sufficiently high probability. Depending on parameters, only two special classes of seedings can be optimal. While one of the classes includes a seeding that is often used in practice, the seedings in the other class are very different. When we relax the assumption of linearity, we find that these classes of seedings are in fact optimal in a sizable number of cases. In contrast to existing literature on optimal seedings, our results are valid for an arbitrarily large number of participants in a tournament.     

Managing Internal R&D Networks in Global Firms: What Sort of Knowledge is Involved?

How should a global firm manage its network of R&D centres in an effective manner? Some have developed an Integrated Network model in which the R&D centres around the world are tightly integrated into a coherent whole. Others have adopted a Loosely-Coupled Network model in which individual “centres of excellence” are given considerable autonomy. In this paper we argue that the way individual R&D units are structured, and the way the entire network is managed, should be based not on administrative heritage, environmental turbulence or management style, but on the basis of the underlying characteristics of the firm’s knowledge assets. In particular we focus on the observability and mobility of the firm’s knowledge assets, the impact these factors have on the way individual R&D centres are structured, and how they relate to one another in the international network. The argument is supported using examples and data from Swedish firms including ABB, Alfa Laval and Ericsson.     

Strategic Sourcing in the Presence of Uncertain Supply and Retail Competition

This study develops an analytical model to evaluate competing retail firms' sourcing strategies in the presence of supply uncertainty. We consider a common supplier that sells its uncertain supply to two downstream retail firms engaging in price competition in a horizontally differentiated product market. The focal firm has a dual‐sourcing option, while the rival firm can only source from the common supplier. We assess the system‐wide effects of supply uncertainty on the focal firm's incentive to pursue the dual‐sourcing strategy. We find that the focal firm's dual‐sourcing strategy can create a win–win situation that leads to increased retail prices and expected profits for both firms. Furthermore, under certain conditions, we show that it is beneficial for the focal firm to strategically source from the common supplier, even if its alternative supplier offers a lower wholesale price. Overall, we identify two types of incentives for adopting the dual‐sourcing strategy: the incentive of mitigating supply risk through supplier diversification and the incentive of strategic sourcing for more effective retail competition.     

Interdependence and Partnership: Building Blocks to Sustainable Development

We are living in a turning point in society's relation with its environment. A first wave of heightened environmental awareness led to the recognition of widespread resource depletion, air and water quality deterioration, forest losses, waste increase, etc., and the need to act on it. The second wave, and we are now on its threshold, is recognition that bringing solutions to this vast range of problems is immensely complex, and will require a much broader-based approach if the solution is to be effective.The interaction needed between business and society in meeting this challenge is increasingly visible, and is resulting in strong and inevitable interdependencies. New forms of participating in society, and of interacting with each other, are being developed by all stakeholders. Moreover this is a potential win–win situation for all involved, and companies can explore these interdependencies and extend them beyond traditional communication into partnerships.     

On the computational complexity of bridgecard

Bridgecard is a classical trick-taking game utilizing a standard 52-card deck, in which four players in two competing partnerships attempt to “win” each round, i.e. trick. Existing theories and analysis have already attempted to show correlations between system designs and other technical issues with parts of the game, specifically the “Bidding” phase, but this paper will be the first to attempt to initiate a theoretical study on this game by formulating it into an optimization problem. This paper will provide both an analysis of the computational complexity of the problem, and propose exact, as well as, approximation algorithms.     

Supplier–Buyer Negotiation Games: Equilibrium Conditions and Supply Chain Efficiency

In a decentralized supply chain, supplier–buyer negotiations have a dynamic aspect that requires both players to consider the impact of their decisions on future decisions made by their counterpart. The interaction generally couples strongly the price decision of the supplier and the quantity decision of the buyer. We propose a basic model for a repeated supplier–buyer interaction, during several rounds. In each round, the supplier first quotes a price, and the buyer places an order at that price. We find conditions for existence and uniqueness of a well‐behaved subgame‐perfect equilibrium in the dynamic game. When costs are stationary and there are no holding costs, we identify some demand distributions for which these conditions are met, examine the efficiency of the equilibrium, and show that, as the number of rounds increases, the profits of the supply chain increase towards the supply chain optimum. In contrast, when costs vary over time or holding costs are present, the benefit from multi‐period interactions is reduced and after a finite number of time periods, supply chain profits stay constant even when the number of rounds increases.