基于多主体的撮合交易模型及算法研究

电子商务交易模型是电子商务应用进一步向前发展的核心,该文首先通过对Internet环境中开放出价双重拍卖模型的分析,并结合Multi-Agent分布式协同求解的特点,提出了一种基于多主体的撮合交易模型,对撮合交易机制及其算法做了描述,证明了该模型的经济有效性等特性,并对多主体环境中的撮合交易模型进行了实验仿真和分析。     

Diversity-and-multiplexing tradeoff and throughput of superposition coding relaying strategy

While the Network Coding cooperative relaying (NC-relaying) has the merit of high spectral ef-ficiency, Superposition Coding relaying (SC-relaying) has the merit of high throughput. In this paper, a novel concept, coded cooperative relaying, is presented, which is a unified scheme of the NC-relaying and SC-relaying. For the SC-relaying strategy which can be considered one-way coded relaying scheme with multi-access channel, the close-form solution of the outage probabilities of the basic signal and additional signal are obtained firstly. Secondly, the Diversity-and-Multiplexing Tradeoff (DMT) characteristics of ba-sic signal and additional signal are investigated entirely as well as the optimal close-form solutions. The compared numerical analysis shows the evaluation error of throughput based on the close-form solution is about 0.15 nats, which is within the acceptable error range. Due to the mutual effect between the both source signals, the available maximal values of the two multiplexing gains are less than 1.     

Systemic tradeoff analysis of fuel cell mobility systems

The development of electric mobility systems with fuel cells is associated with a special constellation of circumstances. The definition of powertrain systems on board electric vehicles is dependent on the refueling infrastructure. At the same time, the development of a hydrogen infrastructure is dependent on vehicle definition and introduction. The joint development of powertrain and infrastructure is a unique opportunity to optimize both the systems. In this paper, we select a number of tradeoffs between the powertrain design and the infrastructure design and calculate technical and financial effects. By way of example we show an optimization of the fuel cell, battery and tank size subject to user behavior and infrastructure constraints. Using powertrain simulations we calculate hybridization ratio and tank size. We then show an exemplary infrastructure layout consisting of transmission and distribution networks. In this paper we consider the infrastructure in Germany by 2030. We then proceed to show the implications of the mutual dependencies between vehicle and infrastructure and to analyze technical potentials and overall system costs. Our main conclusions show ways that could be beneficial for the introduction of electric mobility with fuel cells and a hydrogen infrastructure.     

Euclidean push–pull partial covering problems

This paper considers a bicriteria model to locate a semi-obnoxious facility within a convex polygon. Assuming that a given number of closest points and farthest points may be neglected in the analysis, it considers simultaneously the resulting push and pull partial covering criteria with Euclidean distances. Although both objectives are neither concave or convex, low complexity polynomial algorithms to find all the efficient solutions and the tradeoffs involved are developed by way of higher-order Voronoi diagrams. Comparison of the tradeoff for full covering and partial covering enables decision makers to understand to what extent the maximin and minimax criteria are improved at the expense of neglecting some points. The extensions to different sets of points pulling and pushing the facility and to weighted points are discussed. All methods are illustrated via small scale examples.     

Systems-based modeling of generation variability under alternate geographic configurations of photovoltaic (PV) installations in Virginia

With increased focus on renewable energy in our modern era, it is increasingly important to understand the impact of policies on the performance and reliability of regional energy systems. This research develops a model to understand how geographic dispersion of PV installations impacts the reliability of electricity generated from the total PV network, measured by the variance of the distribution of generated electricity. Using NREL data, beta probability distributions of sunlight (kWh/m²/day) in various regions of Virginia are estimated using a fitting method that minimizes the Kolmogorov–Smirnov test statistic. A Monte Carlo simulation model is developed to measure PV electricity generation from multiple centralized and dispersed configurations over 100,000 days of probabilistic sunlight.     

基于IC产品分档的成品率与效益协调优化设计方法

文章在对IC产品按性能优劣分档的基础上，构造了一个既能体现IC产品的性能优劣和价格大小，又可根据各档次IC产品的市场价格进行调节的性能价格函数：Ep(X)=-1pln{e^-p ∑Mi=1e^P(kiΦi(x)-α)}，从而建立了成品率与效益协调优化模型：maxX^0YE(X^0)=∫R^aEp(X)P(X,X^0)dX。     

A tradeoff between unit capacity and average production cost in spinning reserve optimization

In power systems the spinning reserve (SR) amount can be determined by deterministic or probabilistic techniques. Probabilistic techniques draw more attention since they can consider the economics and the stochastic nature of system behavior and component failures. In probabilistic techniques, the tradeoff between cost and reliability directly affects the SR deployment and it has been extensively analyzed. However, there is another tradeoff which reflects the compromise between the unit capacity and average production cost in the SR optimization problem. This tradeoff impacts the solution accuracy to a certain extent and influences the complexity of the model, and it has not been explicitly analyzed before. In this paper, a new SR optimization method is proposed in which the tradeoff between unit capacity and average production cost is well respected. The proposed method strikes a good balance between solution accuracy and computation efficiency and can obtain better results within a desirable run time compared with those of the previous methods. Besides, the proposed method can also be used to improve the solution of the reserve constrained unit commitment problem. It can lower the total cost by just redistributing the MW dispatch even when the SSR is fixed. The efficiency and validity of the proposed method are verified using the IEEE reliability test system.     

基于灵敏度分析和综合权衡的信息安全管理系统评估

采用灵敏度分析和综合权衡分析方法,研究信息安全管理系统的评估问题.构建一个包括整体评估、性能指标灵敏度分析和系统优化三个层面的信息安全管理系统评估框架,提出了包含综合权衡方法和灵敏度分析方法的用于信息安全管理系统的评估方法.     

Signed quorum systems

With n servers that independently fail with probability of p < 0.5, it is well known that the majority quorum system achieves the best availability among all quorum systems. However, even this optimal construction requires (n+1)/2 functioning servers out of n. Furthermore, the number of probes needed to acquire a quorum is also lower bounded by (n+1)/2. Motivated by the need for a highly available and low probe complexity quorum system in the Internet, this paper proposes signed quorum systems (SQS) that can be available as long as any O(1) servers are available, and simultaneously have O(1) probe complexity. SQS provides probabilistic intersection guarantees and exploits the property of independent mismatches in today’s Internet. Such key property has been validated previously under multiple Internet measurement traces. This paper then extensively studies the availability, probe complexity, and load of SQS, derives lower bounds for all three metrics, and constructs matching upper bounds. We show that in addition to the qualitatively superior availability and probe complexity, SQS also decouples availability from load and probe complexity, so that optimal availability can be achieved under most probe complexity and load values. Haifeng Yu is currently a Researcher at Intel Research Pittsburgh. He is also an Adjunct Assistant Professor at the Department of Computer Science, Carnegie Mellon University. His research interests cover the general area of distributed systems, as well as related fields such as operating systems, database systems, fault-tolerance and large-scale peer-to-peer systems. Haifeng receives his Ph.D. and M.S. from Duke University, and his B.E. from Shanghai Jiaotong University, China. More information about his research is available at http://www.cs.cmu.edu/yhf.     

基于综合权衡分析的信息安全管理系统评估

随着信息时代的到来,每个组织所拥有和需要的信息越来越多,构建信息安全管理系统日益受到各级组织的重视.采用综合权衡分析方法,研究信息安全管理系统的评估问题.构建了一个包括整体评估和系统优化两层含义的信息安全管理系统评估框架,框架完全符合评价、分析及优化的系统工程思想.提出了基于综合权衡方法的信息安全管理系统评估的一套方法集,方法集不仅实现了定性定量相结合的评估思路,而且实现了评估过程的可视化.研究一方面可以总结信息安全管理系统评估的相关理论和方法.另一方面可以有效地指导我国信息安全管理系统的建设工作.