基于差分进化算法的智能组卷方法

如何从庞大试题库中自动生成符合教学和考试要求的一套试卷是目前我国利用计算机进行辅助教学的一个重要研究内容.通过分析用户对组卷的要求和试题结构特征.构建了一个智能优化组卷新模型,同时给出了求解的差分进化算法.数值试验结果表明,所给的方法在组卷效率和质量方面具有更好的性能.     

基于蚁群算法的时序电路测试生成研究

蚁群算法是一种新型进化算法,它提供了解决组合优化问题的框架,但存在着易陷入局部最优解的缺陷。在时序电路测试生成的应用中,通过限制信息素浓度变化范围以及自适应改变信息素挥发因子,在保证算法收敛速度的条件下,提高了算法的全局搜索能力,克服了上述缺陷。实验结果表明,基于该算法的测试生成取得了较高的故障覆盖率和较快的测试生成速度,能够满足实际应用需求。     

混沌密码系统弱密钥随机性分析

弱密钥问题是混沌密码系统设计中的关键问题,已有研究主要从混沌序列退化角度进行分析.然而,本文指出保证混沌序列不退化的密钥参数仍可能构成混沌密码的弱密钥.本文提出以混沌密码序列随机性作为评价标准,应用严格的统计检验方法对混沌密码的弱密钥进行检测.进一步,对一类混沌密码系统进行了弱密钥研究,检测出了该系统大量未被发现的弱密钥.这确证了所提出方法的有效性.另一方面,虽然已有较多研究采用统计检验对混沌比特序列进行测试,但将统计检验用于分析混沌密码弱密钥或弱序列的研究还很少见.本文给出的统计检验弱序列分析,对当前混沌密码统计检验研究是一个很好的补充.     

Restrictive mechanism of flow control among non-cooperative Internet users

The flow and congestion control methods based on one-shot game model with non-cooperative game theory can explain the non-cooperative behavior of Internet users.However,the low effciency of equilibrium solutions affects their utility.Here the behavior of flow and congestion control based on infinitely repeated game models is addressed;the repeated and infinitely repeated flow and congestion control game model is presented; the existence and optimization of the Nash equilibrium point are proved;the discount ...     

Enhancing encoding capacity of combinational test stimulus decompressors

While scan-based compression is widely utilized in order to alleviate the test time and data volume problems,the overall compression level is dictated not only by the chain to channel ratio but also the ratio of encodable patterns.Aggressively increasing the number of scan chains in an effort to raise the compression levels may reduce the ratio of encodable patterns,degrading the overall compression level.In this paper,we present various methods to improve the ratio of encodable patterns.These methods are b...     

The influence of design aesthetics in usability testing: Effects on user performance and perceived usability

This article examined the effects of product aesthetics on several outcome variables in usability tests. Employing a computer simulation of a mobile phone, 60 adolescents (14-17 yrs) were asked to complete a number of typical tasks of mobile phone users. Two functionally identical mobile phones were manipulated with regard to their visual appearance (highly appealing vs not appealing) to determine the influence of appearance on perceived usability, performance measures and perceived attractiveness. The results showed that participants using the highly appealing phone rated their appliance as being more usable than participants operating the unappealing model. Furthermore, the visual appearance of the phone had a positive effect on performance, leading to reduced task completion times for the attractive model. The study discusses the implications for the use of adolescents in ergonomic research.     

Measuring universal intelligence: Towards an anytime intelligence test

In this paper, we develop the idea of a universal anytime intelligence test. The meaning of the terms “universal” and “anytime” is manifold here: the test should be able to measure the intelligence of any biological or artificial system that exists at this time or in the future. It should also be able to evaluate both inept and brilliant systems (any intelligence level) as well as very slow to very fast systems (any time scale). Also, the test may be interrupted at any time, producing an approximation to the intelligence score, in such a way that the more time is left for the test, the better the assessment will be. In order to do this, our test proposal is based on previous works on the measurement of machine intelligence based on Kolmogorov complexity and universal distributions, which were developed in the late 1990s (C-tests and compression-enhanced Turing tests). It is also based on the more recent idea of measuring intelligence through dynamic/interactive tests held against a universal distribution of environments. We discuss some of these tests and highlight their limitations since we want to construct a test that is both general and practical. Consequently, we introduce many new ideas that develop early “compression tests” and the more recent definition of “universal intelligence” in order to design new “universal intelligence tests”, where a feasible implementation has been a design requirement. One of these tests is the “anytime intelligence test”, which adapts to the examinee's level of intelligence in order to obtain an intelligence score within a limited time.     

A level set method based on the Bayesian risk for medical image segmentation

This paper proposes an alternative criterion derived from the Bayesian risk classification error for image segmentation. The proposed model introduces a region-based force determined through the difference of the posterior image densities for the different classes, a term based on the prior probability derived from Kullback-Leibler information number, and a regularity term adopted to avoid the generation of excessively irregular and small segmented regions. Compared with other level set methods, the proposed approach relies on the optimum decision of pixel classification and the estimates of prior probabilities; thus the approach has more reliability in theory and practice. Experiments show that the proposed approach is able to extract the complicated shapes of targets and robust for various types of medical images. Moreover, the algorithm can be easily extendable for multiphase segmentation.     

An adaptive load balancing management technique for RFID middleware systems

In recent years, Radio Frequency Identification (RFID) industries have taken a great interest in utilizing the benefits of RFID for supply chain management, inventory control and various other applications. This paper proposed an adaptive load balancing technique for RFID middleware systems to meet the demands of scalability and heterogeneity. First, we explored five basic load balancing policies, namely, information policy, job selection policy, transfer policy, initiation policy and location policy. Eighteen load balancing schemes were then proposed for RFID middleware systems that were combinations of various types of the five basic load balancing policies. Our empirical study suggested that these load balancing strategies performed differently under different workload statuses. Finally, an adaptive load balancing strategy was proposed. The load balancing schemes and the proposed adaptive load balancing strategy have been implemented in the RFID Middleware Load Management System (RM‐LMS). Copyright © 2010 John Wiley & Sons, Ltd.     

基于远程冰蓄冷空调机房的自动控制设计

为了解决"电力告急,电量有余的状态",争取将用电低谷时期电力填补到高峰时的电力不足。而"移峰填谷"式的蓄冰空调逐渐成为中央空调发展的一个趋势。实现冰蓄冷机房的控制是用WebAccess组态软件完成设定、监控和故障报警等,对冰蓄冷机房进行各种水温、水压、流量和空气温度、湿度、风量、压力、风阀开度等参数进行监控,并且通过通讯实现预测空调负荷从而确定系统工作模式、改变控制策略,这样可提高冰蓄冷空调的运行水平。