针对科研合作网络演化建模的基于Agent实验平台原型

科研合作网络是近年来复杂网络研究的热点问题之一,但当前关于科研合作网络动态演化问题的研究还很不充分,特别是把网络演化和网络中知识创造与传播问题结合起来的研究还鲜见报道.本文在分析Guimera等人提出的一个基于团队组合的科研合作网络演化模型的基础上,提出一个综合网络演化和网络中知识传播的动态网络建模框架暨元模型.进而,以所提出的元模型为依托,开发了一个计算机仿真实验平台原型,以辅助采用基于Agent建模范式的科研合作网络演化和知识传播研究.通过若干建模试验,初步验证了所提出的元模型和相应的实验平台原型的有效性.     

基于概念相关性度量的语义Web服务匹配：模型及匹配器原型

针对当前主流语义Web服务匹配方法过分强调服务请求与服务广告的精确匹配从而导致用户在实际中难以获得真正所需要的Web服务、或在服务自动发现与集成任务中计算负荷过大的问题,本文把基于本体的概念语义相关性度量模型引入Web服务匹配,提出一个新的更"轻便"的语义Web服务匹配模型.该模型使用一系列概念组分别描述服务的服务类别、输入、输出、前提、效果等诸方面的语义信息,在此基础上通过基于本体的概念组之间的相关性度量模型分别评价服务请求与服务描述在这些方面的语义匹配度.总体语义匹配度被定义为输入、输出、前提、效果方面的语义匹配度的加权和.基于这一匹配模型,本文进而研究了相应的服务匹配器原型.初步的数据试验表明,本文所提模型能较好地适应用户需求表述的模糊性,从而提高服务匹配的召回率;从计算复杂性看,本文所提模型也优于基于严格逻辑推理的语义Web服务匹配模型.     

Known and novel noun extensions: attention at two levels of abstraction

Two experiments tested the hypothesis that names direct attention at two levels of abstraction: Known names direct attention to the properties most relevant to the specific category; novel names direct attention to the shape, the property most generally relevant across known object names. English-speaking and Japanese-speaking 3-year-olds were shown a novel object that was named with (a) known nouns referring to things similar in shape or similar in material and color, and (b) novel nouns. Given known nouns, children attended to shape when the name referred to a category organized by shape, but they did not when the name referred to a category organized by other properties. Children generalized novel names by shape. The results are discussed within the debate between shape-based and taxonomic categories.     

Ageing and free-living daily physical activity effects on salivary beta-defensin 2 secretion

This study examined ageing and free-living daily physical activity effects on salivary human beta-defensin 2 (hBD2). A total of 168 healthy elderly and 26 healthy young volunteers underwent saliva sampling. Free-living step count, energy expenditure and activity durations at specific intensity levels (inactive, light, moderate and vigorous) were evaluated. The results show significantly lower salivary hBD2 secretion rates for elderly than for young participants (P < 0.05). Data from elderly participants were stratified by steps per day using quartiles (Q1–Q4) for distribution. Elderly in quartiles respectively showed step counts of 3145 ± 129 in Q1, 5294 ± 83 in Q2, 7001 ± 86 in Q3 and 10,236 ± 416 steps · day^?1 in Q4. In elderly participants, significant differences were found in the mean step count, energy expenditure and activity duration with increasing pedometer-determined activity quartiles. hBD2 secretion rates were significantly higher for Q2, Q3 and Q4 than for Q1 (P < 0.05). Elderly participants in Q3 had the highest hBD2 secretion. In conclusion, these results suggest that moderate physical activity in daily living improves age-related impairment of oral immune function mediated by hBD2. For oral immune function enhancement and for prevention of upper respiratory tract infections in elderly people, we recommend accumulation of more than 7000 steps · day^?1.     

Gene ontology annotation as text categorization: An empirical study

Gene ontology (GO) consists of three structured controlled vocabularies, i.e., GO domains, developed for describing attributes of gene products, and its annotation is crucial to provide a common gateway to access different model organism databases. This paper explores an effective application of text categorization methods to this highly practical problem in biology. As a first step, we attempt to tackle the automatic GO annotation task posed in the Text Retrieval Conference (TREC) 2004 Genomics Track. Given a pair of genes and an article reference where the genes appear, the task simulates assigning GO domain codes. We approach the problem with careful consideration of the specialized terminology and pay special attention to various forms of gene synonyms, so as to exhaustively locate the occurrences of the target gene. We extract the words around the spotted gene occurrences and used them to represent the gene for GO domain code annotation. We regard the task as a text categorization problem and adopt a variant of kNN with supervised term weighting schemes, making our method among the top-performing systems in the TREC official evaluation. Furthermore, we investigate different feature selection policies in conjunction with the treatment of terms associated with negative instances. Our experiments reveal that round-robin feature space allocation with eliminating negative terms substantially improves performance as GO terms become specific.     

Optimal flight technique for V-style ski jumping

This paper describes the results of a numerical study to determine the optimal flight technique for V-style ski jumping. We attempt to answer the question of how a jumper should fly in order to increase their flight distance in a V-style posture. The index of performance in this optimization study is the horizontal flight distance, which is mathematically equivalent to the total flight distance, and the control parameters are the ski-operning angle and the angle of forward lean that the jumper employs (the body-ski angle). The flight trajectory is simulated on the basis of an aerodynamic database constructed from wind tunnel test data. It is found that the ski-opening angle should be increased in the first half of the flight, and then maintained at a constant value during the rest of the jump. Optimal control of the ski-opening angle when there is either a headwind or tailwind is also discussed. It is found that the jumper needs to control the skiopening angle over a wider range in the case of a headwind than in the case of a tailwind. The jumper's skill in controlling the ski-opening angle is very important for increasing the flight distance, especially in the case of a tailwind.     

A Functional Magnetic Resonance Imaging Study of Foreign‐Language Vocabulary Learning Enhanced by Phonological Rehearsal: The Role of the Right Cerebellum and Left Fusiform Gyrus

Psychological research suggests that foreign‐language vocabulary acquisition recruits the phonological loop for verbal working memory. To depict the neural underpinnings and shed light on the process of foreign language learning, we conducted functional magnetic resonance imaging of Japanese participants without previous exposure to the Uzbek language using learning of novel Uzbek words. During encoding, spoken Uzbek words and corresponding visual objects were shown, and subjects either overtly repeated the words (phonological rehearsal) or overtly rehearsed numbers (phonological suppression). Phonological rehearsal improved the encoding performance. A learning‐related decrease in rehearsal‐specific activation was found in the left fusiform gyrus, right inferior temporal gyrus, and right cerebellum. Recollection of the phonologically rehearsed words activated the right cerebellum and left fusiform gyrus more prominently than recollection of the phonologically suppressed words in a performance‐dependent manner. The phonological loop might provide the temporal and fragile registration of the articulatory pattern that is converted into a more durable form in the right cerebellum, which is in turn integrated with the object information in the fusiform gyrus.     

Teachers’ Autonomy in Today's Educational Climate: Current Perceptions From an Acceptable Instrument

This research evaluated the psychometric properties of Friedman's (1999) Teacher Work-Autonomy Scale (TWA) to determine whether it was an acceptable instrument to measure U.S. teacher autonomy in the present educational context. A second purpose was to ascertain the current status of teachers’ perceptions of their autonomy from a sample of U.S. teachers. Four hundred seventy-seven teachers from three public schools in Michigan participated in this study for a response rate of 30%. Factor analysis confirmed the multifaceted nature of teacher autonomy; however, somewhat different factor structures were found for the elementary and secondary teachers in this study, in comparison to that of Friedman. The TWA, without major modifications, appeared to be a valid and reliable instrument for use with a U.S. secondary sample but with limitation with an elementary sample. Elementary and secondary teachers perceived autonomy in the different factors in identical order, but with significant differences between their scores. Differences in school structure and conceptions of autonomy may have contributed to grade-level discrepancies. The findings suggest that administrators may be able to enhance teacher autonomy by releasing some of their power to include teachers in school leadership, specifically in the two areas teachers perceived with lowest autonomy: school finances and professional development.     

Sport event innovativeness: Conceptualization,measurement, and its impact on consumer behavior

Although scholars have had a long-standing interest in product innovation based on technological development, limited attention has been devoted to the study of the innovation of sport event experiences. Two quantitative studies, from the consumer's perspective, were completed to validate the proposed conceptualization of sport event innovativeness composed of six dimensions (player performance, respectful access, self-service technology, aesthetic environment, fan community, and loyalty program), and to examine the hypothesized relationships impacting consumer behavior. Including the dimensions of player performance, fan community, and loyalty program, extends previous research that has focused primarily on technology and process-based innovations. The results indicate the effects of the six dimensions on overall innovativeness are contingent on a consumer's age. The ideas merit further research with respect to formulating an explanation of what factors contribute most to connecting consumers to sport organizations through innovative sport event experiences.