Web proxy cache replacement scheme based on back-propagation neural network

Web proxy caches are used to reduce the strain of contemporary web traffic on web servers and network bandwidth providers. In this research, a novel approach to web proxy cache replacement which utilizes neural networks for replacement decisions is developed and analyzed. Neural networks are trained to classify cacheable objects from real world data sets using information known to be important in web proxy caching, such as frequency and recency. Correct classification ratios between 0.85 and 0.88 are obtained both for data used for training and data not used for training. Our approach is compared with Least Recently Used (LRU), Least Frequently Used (LFU) and the optimal case which always rates an object with the number of future requests. Performance is evaluated in simulation for various neural network structures and cache conditions. The final neural networks achieve hit rates that are 86.60% of the optimal in the worst case and 100% of the optimal in the best case. Byte-hit rates are 93.36% of the optimal in the worst case and 99.92% of the optimal in the best case. We examine the input-to-output mappings of individual neural networks and analyze the resulting caching strategy with respect to specific cache conditions.     

钢铁企业全厂仪表维修设施设计初探

以我国某大型钢铁企业全厂仪表维修设施的设计方案为例,简要说明了仪修设施的设计原则、全厂仪表维修的一般解决方案,较详细地介绍了仪修设施专业划分、实验室及维修车间的设置和主要设备构成,为该类项目的设计和工程建设提供一定参考。     

民俗文化语境下的高校艺术设计教育

尽管当下中国高等艺术设计教育呈现出前所未有的迅猛发展态势,但在学科建设和教育实施方面也显示出一定的不足和问题,在诸多直接的原因之外,本文立足于深层文化思考,对中国视觉民俗文化主体之一的民间美术所蕴涵的文化意义作了进一步的透析,以期寻绎出在宏阔的民俗文化生态中我国高校艺术设计教学改革的策略与教育发展取向。     

从工艺美术教育到艺术设计教育——称谓变迁背后的问题

本文通过分析工艺美术和艺术设计所依附的社会形态的差异性,以及对工艺美术教育和艺术设计教育称谓变迁现象的考察,显现当代中国工艺美术与艺术设计教育发展的脉络,并以此为基础,揭示当代艺术教育史的话语中,艺术设计与工艺美术之间关系复杂难言的根本原因。     

The effect of time of day on injury patterns amongst adolescents in Australia

Labour force participation of adolescents in Australia is growing at an unprecedented rate. This increased participation is coupled with a growing realisation of the vulnerability of adolescents in the labour market in terms of occupational injury. Despite recent evidence that time of day may be an important determinant of adolescent injuries, the impact of non-standard and night work on adolescent injury rates has received scant attention to date. The current study addresses this shortcoming by examining injury patterns of 3201 working adolescents in Queensland. Results revealed that female adolescents are 2.5 times more likely to sustain an injury on day shift and 4.71 times more likely to sustain an injury on night shift than their adult counterparts when total work hours are taken into consideration. Similar results were found for male adolescents with an injury to work hours ratio of 2.19 on day shift and 3.05 on night shift. These findings point to the value of considering the temporal pattern of adolescent work in future research aimed at minimising injuries at work and improving the work experience of tomorrow's workforce.     

坦克设计新发展

本文提出“针对式坦克发展战略”主要内容,它要求“突破性新概念高新技术”,获得“减法设计方法”,因而形成“坦克发展新道路”.运用“系统总体取胜”的系统工程理论,处理好坦克全系统“综合”、全系统与分系统“配置”、分系统与分系统“匹配”、全系统与人及作战环境“适应”四大关系,以“相互同水平组合”替代“单项高水平爬坡”.通过“从系统总体着眼、由边际零部件突破”的途径,善于从各个部分或部件之间的结合部加以突破,实现坦克设计新发展.     

Economic modeling of board test strategies

A long and deep recession, coupled with continuous competitive pressure to reduce costs, is forcing many companies to review their test strategies. Testing costs have become a more significant proportion of the overall manufacturing cost even though manufacturing yields have increased dramatically over the past ten or twelve years. This causes attention to be focused on testing costs as a key source of cost reduction. The increased use of DFT and the integration of design and test are very positive moves towards controlling testing costs but other methods employed can often backfire. The increased use of low priced testers is one such method. The pressure to reduce costs, higher process yields and exhortations that testing adds no value can lead the test engineering manager to take the cheap route. In reality this can often turn out to be an expensive decision. The only way to avoid expensive mistakes is to perform an economic analysis of the alternative courses of action. In most cases this is done, but not always in the right manner or with the necessary amount of detail to make the comparisons meaningful. This article discusses the need for effective cost analysis of test strategies and highlights some of the pitfalls.     

含泥砂河流水轮机增容改造的探讨─刘家峡2~＃水轮机增容改造

本文简要叙述了刘家峡电厂水轮机增容改造中的水力研究、结构设计、中间试验、材料选择以及制造工艺等方面内容,并探讨了减轻泥砂磨蚀的措施。该水轮机的增容改造经验对含泥砂河流水轮机的设计与改造是有益的。     

Japanese educational and learning systems in the post-industrial society: A value chain of educational and learning systems

Japan's educational system has some major problems. The most important among these concerns is the basic concept of the educational process and the goal of education. The old concept of public educational systems has become outdated in today's Japanese society, although this concept had supported social and spiritual faith, economic success and selfless devotion to one's country for more than 100 years. Now, Japanese people need a new concept of the educational process and the goal of education for the twenty-first century. The paper proposes a value chain of educational and learning systems aimed at building a network consisting of multiple fields for fostering future human resources.     

数字测控系统电磁兼容性设计技术

从模块化的角度,系统、全面地探讨了数字测控系统电磁干扰的来源及机理,并依据所建立的干扰模型和设计不等式,给出了丰富的设计对策。