建构主义视野下基于云计算的网络教学环境设计

云计算技术应用于教育领域是教育信息化发展的必然趋势。文章在分析云计算应用于教育领域优势的基础上,结合建构主义理论,设计了一种基于云计算的网络教学环境,并对该教学平台的组成架构和功能模块进行了阐述。     

太赫兹技术对二氯苯胺两种同分异构体的检测

采用太赫兹时域光谱技术测量了3,4-二氯苯胺和2,5-二氯苯胺在0.2～2 THz波段的吸收谱,3,4-二氯苯胺在1.00 THz,1.48 THz,1.88 THz处有3个吸收峰,2,5-二氯苯胺在0.83 THz,1.04 THz,1.17 THz处有3个吸收峰,吸收峰峰位强度也有明显不同。采用密度泛函理论进行理论光谱计算,理论光谱与实测光谱一致性良好。结果表明通过太赫兹时域光谱技术可以实现3,4-二氯苯胺和2,5-二氯苯胺2种同分异构体的指纹检测,为太赫兹波段有明显特征吸收峰的毒性物质检测提供了一种快速、准确的方法。     

A Note on Multiple Comparisons Using Rank Sums

In a one-way layout design, the rank-sum procedures proposed by Steel [6] and Dunn [1] for the problem of comparing all pairs of treatments are compared and found to have equivalent asymptotic properties. The asymptotic relative (Pitman) efficiency of these nonparametric procedures relative to the classical solutions is shown to be the same as the efficiency of the corresponding two-sample rank-sum tests relative to the two-sample Student's t-test.     

A novel approach using Dynamic Social Impact Theory for optimization of impedance-Tongue (iTongue)

This paper presents a novel multiobjective wrapper approach using Dynamic Social Impact Theory based optimizer (SITO). A Fuzzy Inference System in conjunction with support vector machines classifier has been used for the optimization of an impedance-Tongue for the classification of samples collected from single batch production of Kangra orthodox black tea. Impedance spectra of the tea samples have been measured in the range of 20 Hz to 1 MHz using a two electrode setup employing platinum and gold electrodes. The proposed approach has been compared, for its robustness and validity using various intra and inter measures, against Genetic Algorithm and binary Particle Swarm Optimization. Feature subset selection methods based on the first and second order statistics have also been employed for comparisons. The proposed approach outperforms the Genetic Algorithm and binary Particle Swarm Optimization.     

多用途平面有限元程序的理论基础及其在水库诱震研究中的应用

通过分析基本微分方程和边界条件,证实固结问题是由平面应变和流体通过多孔介质的渗流这两个问题有机地组合起来的。这从理论上保证了一个程序可同时处理平面应变、渗流和固结这三个不同性质的定解问题。 该文应用应力～孔隙压耦联理论,并通过四个模型的计算,揭示新丰江水库地震的发生不仅与库水的耦联作用和库区存在的陡倾角、走滑兼正断层作用有关,而且还与库区存在的高密度基底以及库水的加、卸载方式有关。     

The Pareto managerial principle: when does it apply?

The well-known 80/20 Pareto principle and its refinement into “A”, “B”, and “C” categories give rise to a managerial methodology consisting of three steps: classification; differentiation; and resource allocation. This is an easy-to-implement and extremely effective methodology. It starts with the creation of “Pareto diagrams”, i.e. bar charts of attributes and their relative frequency, presented in descending order. Typically, Pareto diagrams are useful in that they provide managers with a summary of practical information, revealing critical attributes. However, sometimes a Pareto diagram is less informative than it might be, because the relative frequency is almost uniform. The objective of this article is to provide an analytical tool (an index) that employs the above-mentioned methodology to measure the closeness of empirical Pareto diagrams to an “ideal” Pareto diagram. The index developed is based upon entropy.     

Identifying the psychological determinants of risky riding: An application of an extended Theory of Planned Behaviour

The Theory of Planned Behaviour (TPB) plus moral norms, anticipated regret, past behaviour, self-identity and perceived susceptibility was applied to predicting motorcyclists’ intention to ride above the speed limit and ride at inappropriate speeds. Past behaviour, control beliefs, attitudes, moral norm, normative beliefs, age and self-identity explained 60% of the variance in motorcyclists’ intention to exceed the speed limit on motorways (N = 1381). A total of 62% of the variance in motorcyclists’ intention to really go for it on rural roads was accounted for, with past behaviour, attitudes, control beliefs, age, normative beliefs, anticipated regret, self-identity, behavioural beliefs and training status being significant (N = 1116). Finally, attitudes, past behaviour, control beliefs, moral norm, anticipated regret, behavioural beliefs, normative beliefs, engine size and self-identity explained 57% of the variance in motorcyclists’ intention to ride faster than felt safe in order to keep up with the group (N = 1940). The belief-based measures also successfully differentiated between those who intended to speed and those who did not. Theoretical and practical implications of the findings are discussed.     

The study of an Easy-to-Use DBR and BM system

The concept and advantages of the Drum–Buffer–Rope (DBR) scheduling and buffer management (BM) system are now widely accepted and recognized by the industrial communities. Therefore, there are several types of commercial DBR and BM business solution software such as OPT21?, DISASTER?, Visual DBR?, Synchrono?, Drummer?, etc., on the market. However, prior to implementation of any of these, factories must first gather a complete data set for their perspective throughput nets. This means that the users will be required to enter and maintain a complicated database and the degree of difficulty of the entire software system implementation process will also increase. Furthermore, it is also unrealistic to maintain the accuracy of these dynamic data in the fast-paced and competitive business environment. Therefore, in this article, we have proposed the Easy-to-Use DBR and BM system concept. The term ‘Easy-to-Use’ refers to the fact that users will be required to enter and maintain a minimal set of fundamental data to satisfy the factories’ operation needs. The system framework mentioned in our article contains the full and complete function of the DBR and BM system but with very limited data maintenance by the users. Therefore, with less procedural complexity, this system can produce a higher range of operational application and can attract higher interest from the users. The concept of simplified throughput net design proposed in our article cannot only be used as a reference when factories develop their own information systems, but can also provide a new design model and algorithm for the system software developers as well. Since the database maintenance is significantly simplified, the factories can quickly adapt to any changes in the dynamic, rapid-changing, and highly competitive production environment. In the article, we first describe the concept of the Easy-to-Use DBR and BM system and the steps to simplify the information system by using a simple throughput net. We then explain the system framework and design methodology. At the end, we have used a prototype system to demonstrate and to verify the applicability and efficiency of the concept and framework mentioned in our article.     

Child restraint seat use behavior and attitude among Japanese mothers

OBJECTIVES: The purpose of the study was to assess associations between child restraint seat use and attitudes among Japanese mothers. MATERIALS AND METHODS: Mothers whose children were under 6 years of age were recruited through 11 kindergartens located in Kanagawa prefecture, Japan. Questions were developed based on the Health Belief Model and the Theory of Reasoned Action. Past use and future intentions to use, perceived risk of injury, knowledge of safety, attitudes toward use, subjective norms, and safety values related to safety seats were asked. RESULTS: A total of 552 complete questionnaires was obtained. Of 500 car owning households, 54.2% used child restraint seats inconsistently on short drives, and 36.4% did so on long drives. Three variables were associated with inconsistent use on short drives: frequent child resistance to sitting in a restraint seat; mothers' feeling hassled by child restraint seat use; and, mothers' agreement with the lack of need to use a restraint seat when another adult is in a car. Two variables were associated with inconsistent use on long drives: lower subjective norm of husband and frequent child resistance. CONCLUSIONS: In-car environmental modification and parent education need to be considered to increase child restraint seat use among Japanese households.     

Lack of energy equipartition in homogeneous heated binary granular mixtures

 We consider the problem of determining the granular temperatures of the components of a homogeneous binary heated mixture of inelastic hard spheres, in the framework of Enskog kinetic theory. Equations are derived for the temperatures of each species and their ratio, which is different from unity, as may be expected since the system is out of equilibrium. We focus on the particular heating mechanism where the inelastic energy loss is compensated by an injection through a random external force (“stochastic thermostat”). The influence of various parameters and their possible experimental relevance is discussed. Received: 18 February 2002