基于下一代互联网技术的信息网格技术探析

该文首先解释了信息网格的定义,然后与网格计算技术进行了比较,接着讨论了信息网格的发展趋势、关键技术、典型应用,再接着讨论了使用信息网格的注意事项,最后论述了应用信息网格技术的意义,对广大计算机爱好者学习信息网格具有重要的理论和实践指导意义。     

Tool support for learning Büchi automata and linear temporal logic

We introduce a graphical interactive tool, named GOAL, that can assist the user in understanding Büchi automata, linear temporal logic, and their relation. Büchi automata and linear temporal logic are closely related and have long served as fundamental building blocks of linear-time model checking. Understanding their relation is instrumental in discovering algorithmic solutions to model checking problems or simply in using those solutions, e.g., specifying a temporal property directly by an automaton rather than a temporal formula so that the property can be verified by an algorithm that operates on automata. One main function of the GOAL tool is translation of a temporal formula into an equivalent Büchi automaton that can be further manipulated visually. The user may edit the resulting automaton, attempting to optimize it, or simply run the automaton on some inputs to get a basic understanding of how it operates. GOAL includes a large number of translation algorithms, most of which support past temporal operators. With the option of viewing the intermediate steps of a translation, the user can quickly grasp how a translation algorithm works. The tool also provides various standard operations and tests on Büchi automata, in particular the equivalence test which is essential for checking if a hand-drawn automaton is correct in the sense that it is equivalent to some intended temporal formula or reference automaton. Several use cases are elaborated to show how these GOAL functions may be combined to facilitate the learning and teaching of Büchi automata and linear temporal logic. This work was partially supported by the National Science Council, Taiwan (R.O.C.) under grants NSC94-2213-E-002-089, NSC95-2221-E-002-127, NSC95-3114-P-001-001-Y02 (iCAST 2006), NSC96-3114-P-001-002-Y (iCAST 2007), and NSC97-2221-E-002-074-MY3.     

对七星彩开奖号码的随机性卡方检验

以我国连续200期七星彩开奖号码为样本,采用卡方检验法检验每个字符出现的概率是否相同,并检验同一期开奖号码中字符重复出现的次数是否在可接受的范围之内。统计检验表明：我国七星彩的开奖号码具有较好的随机性。     

元青花《昭君出塞》罐艺术特征与主题思想研究

"昭君出塞"故事源于汉代,绵延流传,元青花《昭君出塞》罐表现的即为"昭君出塞"故事题材。元青花《昭君出塞》罐具有鲜明的艺术特征,同时,亦具有丰富而深邃的主题思想内涵。     

日本法隆寺西院五重塔玄数初探

为了研究中国古老的山西应县木塔维修问题，基于中华道教玄学首次识别了日本奈良法隆寺西院五重塔古木建筑原结构设计的主要尺寸和西院的建筑布局，结果对亚洲建筑科技史和中华古木建筑加固修复都有重要参考价值。     

Attack–norm separation for detecting attack‐induced quality problems on computers and networks

Cyber attacks on computer and network systems induce system quality and reliability problems, and present a significant threat to the computer and network systems that we are heavily dependent on. Cyber attack detection involves monitoring system data and detecting the attack‐induced quality and reliability problems of computer and network systems caused by cyber attacks. Usually there are ongoing normal user activities on computer and network systems when an attack occurs. As a result, the observed system data may be a mixture of attack data and normal use data (norm data). We have established a novel attack–norm separation approach to cyber attack detection that includes norm data cancelation to improve the data quality as an important part of this approach. Aiming at demonstrating the importance of norm data cancelation, this paper presents a set of data modeling and analysis techniques developed to perform norm data cancelation before applying an existing technique of anomaly detection, the chi‐square distance monitoring (CSDM), to residual data obtained after norm data cancelation for cyber attack detection. Specifically, a Markov chain model of norm data and an artificial neural network (ANN) of norm data cancelation are developed and tested. This set of techniques is compared with using CSDM alone for cyber attack detection. The results show a significant improvement of detection performance by CSDM with norm data cancelation over CSDM alone. Copyright © 2006 John Wiley & Sons, Ltd.     

Sinopec Sees Significant Growth for Net Profit in 2007

China Petrochemical Corporation （Sinopec）, a leading oil refiner, posted a net profit of 70 billion yuan （9.63 billion U.S. dollars） in 2007. Sinopec made a net profit of 50.66 billion yuan in 2006. The huge profit can be attributed to cost control, resources integration and technological innovation, according to Cai Xiyou, a senior executive of Sinopec.     

ON WEIGHTED PORTMANTEAU TESTS FOR TIME‐SERIES GOODNESS‐OF‐FIT

Recent work in the literature has shown weighted variants of the classic portmanteau test for time series can be more powerful in many situations. In this article, we study the asymptotic distribution of weighted sums of the squared residual autocorrelations where both the sample size n and maximum lag of the statistic m grow large. Several weighting schemes are introduced, including a data‐adaptive statistic in which the weights are determined by a function of the sample partial autocorrelations. These statistics can provide more power than other portmanteau tests found in the literature and are much less sensitive to the choice of the maximum correlation lag. The efficacy of the proposed methods is further demonstrated through an analysis of Australian red wine sales.     

苏州瑞光塔设计模数初探

苏州瑞光塔开建于北宋景德元年(1004年),是一座八面七级的砖芯木檐楼阁式塔。本文对现有测绘数据进行分析,推算出瑞光塔建造使用的营造尺长,推断出设计中可能使用的模数,并用相关古塔设计理论与该模数对比分析。     

桉木制单板层积材的抗压强度预测模型

为了研究桉木制单板层积材的抗压强度预测模型,进行了342个试件的抗压试验,分析了试件纹理角度、胶层角度对其抗压强度、弹性模量和破坏模式的影响.采用指数模型拟合试件抗压强度,并通过卡方（χ2）检验来验证该指数模型和Hankinson公式、Norris公式以及GB 50005—2003规范公式对抗压强度的拟合度.结果表明：随着试件纹理角度、胶层角度的增加,其抗压强度和弹性模量均显著下降;抗压试件的破坏模式有3种,为纤维褶皱破坏、剪切破坏和压溃破坏;指数模型、Hankinson公式和Norris公式均能较好地拟合抗压强度,而GB 50005—2003规范公式拟合的抗压强度值偏高.