Optimal contest design under reverse-lottery technology

In this paper, we study effort-maximizing contest design under the “reverse” nested lottery contest model of Fu et al. (2014) — which is the “mirror image” of the conventional nested lottery contest of Clark and Riis (1996). We show that under the reverse-lottery technology, a single-stage winner-take-all grand contest dominates all other feasible designs when the contest is sufficiently noisy. This result is in dramatic contrast to the conventional wisdom on the optimality of multistage elimination contests that is grounded under the conventional nested lottery contest technology in the literature. In the framework of a noisy-performance ranking model, the conventional and reverse models differ only in the noise on players’ performance. Our study therefore reveals the important role that the noise term plays in modeling imperfectly discriminatory contests.     

Link bidding in laboratory networks

This paper presents the results of laboratory experiments that explore the network formation process. Performances of three institutions, each derived from theoretical models found in the literature, are compared. All three institutions are found to generate similar levels of efficiency. In hospitable environments, the institutions achieve 85% efficiency, but all three fail to generate any positive surplus when stress tested.Received: 28 May 2002, Accepted: 14 March 2003, JEL Classification: A14, C70, C90, D20The authors wish to thank the International Foundation for Research in Experimental Economics for financial support in the form of subject payment money. This work has greatly benefited from comments by an anonymous referee, Rob Gilles, participants in the Social Network session at the 2001 Southern Economic Association Meetings, and seminar participants at the University of Arkansas.     

Optimal design for interacting blocks with OAVS incidence

Optimal design is studied for multiway cross classifications in which the blocking factors exhibit interaction and in which the incidence structure of the blocking factors describes an orthogonal array. Assuming the orthogonal array to be of sufficient strength (enough to allow orthogonal estimation of all of the interaction terms), easily used forms of the information matrix for treatment estimation are derived, and optimality conditions are stated. Some illustrative construction examples are given.     

关于人类中心主义的伦理辩护

文章首先总结得到人类中心主义的本质,并在与非人类中心主义进行比较分析的过程中,从伦理的角度对人类中心主义的积极方面加以辩护,最后指出其在支持社会可持续发展中的重要作用。     

Optimal highway design and user welfare under value pricing

This paper investigates the optimal design of highways operated under a form of congestion pricing called value pricing. Value pricing involves dividing a highway into free and priced lanes so that in equilibrium the highway effectively operates at two levels of service, with those users placing a higher value on travel time savings selecting the faster, priced route. A tractable analytical framework is developed which allows analysis of equilibrium and welfare on value priced highways when users vary in their value of time. The model is used to characterize optimal toll and capacity policies, as well as investigate the fiscal implications of value pricing. The analysis concludes with results on how welfare changes induced by value pricing are distributed over the population of users when the government finances any funding shortfall through a non-discriminatory taxing mechanism. A realistic numeric example is used to illustrate how the model can be applied to evaluation of actual and proposed value pricing implementations.     

Optimal versus orthogonal and equivalent-estimation design of blocked and split-plot experiments

This article provides an overview of the recent literature on the design of blocked and split-plot experiments with quantitative experimental variables. A detailed literature study introduces the ongoing debate between an optimal design approach to constructing blocked and split-plot designs and approaches where the equivalence of ordinary least squares and generalized least squares estimates are envisaged. Examples where the competing design strategies lead to totally different designs are given, as well as examples in which the optimal experimental designs are orthogonally blocked or equivalent-estimation split-plot designs.     

加强高校的国防教育是培养高素质人才的必然要求

国防是国家生存发展的安全保障,高校是培养高素质人才的重要基地,国防教育是素质教育的重要内容,国防素质是高素质人才应有的素质,加强高校国防教育是培养高素质人才的必然要求。     

城市立交桥下空间的利用与设计

分析了立交桥下空间利用现状,针对桥下空间形态、桥墩形态的特征及功能利用取向,从公共性与适宜性结合、个性化与人性化结合、连续性与整体性结合、艺术性与生态性结合、安全性与适度性结合等六个方面,探讨了桥下空间的利用及设计原则。认为立交桥下的空间环境是一种宝贵的人工环境,应科学地利用这一环境,应从城市设计的角度对立交桥进行综合性的艺术设计。     

Optimal locations and flow allocations for aggregation hubs in supply chain networks of perishable products

Establishment of aggregation hubs in a supply chain network (SCN) is typically a facility location-allocation (FLA) decision, which is known to be a NP-hard optimization problem. Considering the flow of heterogeneous perishable products, like fresh produce, with different spoilage rates, further increases the complexity of such a problem. This is due to the effect of transportation time and conditions, services provided in the hub, and hub proximity to supply sources, on the quality and quantity of products eventually reaching the demand destinations, and hence on the location-allocation decision. In this paper, this problem is formulated as a mixed integer linear programming (MILP) model that considers a number of problem characteristics simultaneously for the first time, to minimize the transportation, spoilage, processing, and capacity-based hub establishment costs. Due to its complexity, two hybrid algorithms that combine a meta-heuristic with a perishability-modified transportation algorithm, are proposed to solve the problem. The algorithms are based on binary particle swarm optimization (BPSO) and simulated annealing (SA). Taguchi analysis is used to tune the significant parameters of both algorithms considering different problem sizes. Computational analysis is further conducted to evaluate and compare the performances of the algorithms using randomly generated test instances and exact solutions obtained using CPLEX. Results show that while both algorithms are capable of obtaining optimum solutions for most instances, the hybrid BPSO slightly outperforms the hybrid SA in terms of consistency and solution time.     

Optimal designs under two related models for interference

We consider two related models for interference: one having different directional neighbour effects and one with the same neighbour effects. We show that optimal designs for one model can be obtained from optimal designs for the other model. Acknowledgement. We are grateful to H. Kushner for advance notice of his work. SP was supported by the Isfahan University of Technology, Iran.     

Optimal design of trade institutions

We model an economy with social institutions that facilitate trade and induce three types of costs: establishment costs, access costs, and use costs. Use costs are specific transaction costs related to the use of these trade institutions. We assume that a trade institution is economically completely determined by the costs it imposes and by the effects on the trades it facilitates. We extend the Pareto efficiency concept to include various modes of organization of social institutions: the costs and benefits of these organizations are expressed in the trades they facilitate.Within this setting we discuss a valuation equilibrium concept, in which all agents use a common conjectural price system that assigns to every trade institution the price vector that would prevail under it. This feature of the equilibrium is important in securing the second welfare theorem, and is new to the analysis of economies with costly trade. Since the use costs can be nonlinear, there are non-convexities that prevent the second welfare theorem from obtaining in a finite economy, but we show it for large economies.Received: 3 April 2002, Accepted: 30 April 2003, JEL Classification: D59, D70, H49Robert P. Gilles: donewhile visiting the Center for Economic Research, Tilburg University, Tilburg, The Netherlands. Financial support from the Netherlands Organization for Scientific Research (NWO), grant B46-390, is gratefully acknowledged.Dimitrios Diamantaras: Part of this research wasSupport from Temple University via a Fuller research fellowship is gratefully acknowledged.The authors would like to thank Suzanne Scotchmer, Andreu Mas-Colell, Marcus Berliant, Shlomo Weber, Hans Haller, Dhanajay Gokhale, Julian Manning, and two anonymous referees for their valuable comments and discussions of previous drafts of this paper. A previous version of this paper was circulated as Equilibria of economies with costly trade.     

论产品生态设计与成本企画的结合

文章从环保产品开发的理念出发,阐述了产品生态设计的基本概念和设计流程,提出实施生态设计与成本企画方法结合的思想,作为企业进行环境成本管理的另一有效途径。     

Cooperation through imitation and exclusion in networks

We study the coevolution of networks and action choices in a Prisoners' Dilemma. Agents in our model learn about both action choices and choices of interaction partners (links) by imitating successful behavior of others. The resulting dynamics yields outcomes where both cooperators and defectors coexist under a wide range of parameters. Two scenarios can arise. Either there is “full separation” of defectors and cooperators, i.e. they are found in two different, disconnected components. Or there is “marginalization” of defectors, i.e. connected networks emerge with a center of cooperators and a periphery of defectors.     

Time-varying road network design for urban hazmat transportation

Hazmat transportation in cities faces significant risks that may cause catastrophic losses to humans. From the perspective of the regulator, the main responsibility is to mitigate hazmat transport risk by determining the availability of road networks to hazmat carriers. Based on the time-variant population distribution, the hazmat transport risk was assessed via the total population exposure associated with the resident and variable populations at different times. We propose a risk-minimizing urban hazmat road network design model for multiple types of hazmats, considering time-varying traffic. The model was applied to a realistic case study of hazmat transportation in a densely populated urban area with complex traffic in Shanghai, China.     

抗震概念设计在建筑结构设计中的应用

针对目前建筑结构设计当中墨守成规的现象,提倡采用概念设计思想来促进结构工程师的创造性,推动结构设计的发展。工程技术人员在建筑、结构设计过程中必须充分运用抗震概念设计的优化准则及其相应的构造措施,确保工程质量。     

Reliable design of a congested disaster relief network: A two-stage stochastic-robust optimization approach

The preparedness of humanitarian relief networks can be enhanced by pre-positioning resources in strategic locations and using them when disasters strike, a strategy that gives rise to a two-stage planning problem. This paper presents a novel two-stage stochastic-robust optimization approach for integrated planning of pre- and post-disaster positioning and allocation of relief resources, while taking into consideration the uncertainty about demand for relief services and disruptions in the relief facilities and the transportation network. The proposed approach enables planners to effectively use limited historical data and imperfect experts’ opinions to obtain robust solutions while avoiding the over-conservatism of classical robust optimization methods. The objective sought is to minimize the expected total time victims need to receive assistance, including both access time to facilities and waiting/service time in them. Congestion in relief facilities is accounted for by modeling them as queuing systems and penalizing waiting time. A decomposition method based on column-and-constraint generation is implemented to solve the problem, whereas the nonlinear terms corresponding to queuing in the second-stage problem are handled using a direct search procedure. Applicability of the proposed approach is demonstrated through a real case study and the numerical results are analyzed to draw managerial insights.     

优化设计与设计造价控制

实行全过程的建设工程造价控制的重点在设计阶段,采用技术与经济相结合的方法优化设计是控制工程造价的最佳切入点。     

Classification of various attacks and their defence mechanism in online social networks: a survey

Due to the popularity and user friendliness of the Internet, numbers of users of online social networks (OSNs) and social media have grown significantly. However, globally utilised, social networks are the consequence of the lack of understanding of secrecy and protection on OSN and media has increased. Secrecy and surety of OSNs need to be inquired from various positions. According to recent studies, OSN users expose their private information such as email address, phone number etc. In this paper, we have presented a high-level classification of recent OSN attacks for recognising the problem and analysing the blow of such attacks on World Wide Web. We have also discussed OSN attacks on different social networking web applications by citing certain recent reports such as Kaspersky security network and Sophos security threat report. We also offer some simple-to-implement user practice tips to protect the system and user’s information. In addition to this, we have discussed a comprehensive analysis of numerous defensive approaches on OSN security. Lastly, based on the acknowledged strength and faults of these defensive approaches, we have explained open research issues.     

集成适应理论在城市道路景观设计中的应用

分析了我国城市道路景观存在的问题,在将城市道路景观作为一个复杂网络综合体的基础上,从系统范畴的角度探讨了"集成适应"道路景观设计理念,为未来我国城市道路景观建设提供了一种新的思路.     

不确定环境下二级供应链机制设计

本文研究了一个不确定环境下二级供应链机制设计问题。供应商的类型被刻画为一个模糊变量。应用委托代理理论建立其期望效用最大化问题的模型。利用庞特立亚金极大值原理给出了模型最优解的必要条件。