金融危机前后C5航线远期运费波动溢出效应比较     

朱意秋  郑文璪 《上海海事大学学报》2012,33(1):67-72

基于远期运费协议(Forward Freight Agreement,FFA)市场与干散货运输实体市场间的波动溢出关系对正确评价FFA市场的效率及企业是否参与该市场的决策具有重要意义.用AR,VAR和VEC所提取的均值方程残差作为溢出因子代入GARCH和EGARCH波动方程中,以考察C5航线在金融危机前后波动溢出效应的变化.主要的实证结论:该航线的远期和即期存在双向波动溢出;远期对即期的波动溢出在金融危机后获得加强;远期的当期残差在各阶段的溢出强度远远高于滞后一期的残差,说明当天的远期信息深度影响着当天的即期实体市场。  相似文献   

Reproducibility of an isokinetic eccentric muscle endurance task     

《European Journal of Sport Science》2013,13(5):311-319

Abstract

Despite the widespread use of isokinetic eccentric muscle endurance protocols, no research has examined the absolute and relative reliability of such tests. The aim of this study was to examine the reliability of an isokinetic eccentric knee muscle endurance task. Fifteen healthy untrained males volunteered to take part in the study and written informed consent was obtained. The procedures received approval from the University Research Ethics Committee. Participants visited the laboratory on three separate occasions: 2 weeks before testing to familiarize them with the experimental procedures, and on two separate occasions, 2 weeks apart and at the same time of day. Isokinetic eccentric knee extension and flexion movements of the dominant limb were performed using a calibrated dynamometer (Biodex System 3). Range of motion during testing was set using voluntary maximal full extension (0 rad) to 1.57 rad of knee flexion and testing was conducted at 1.56 rad · s^?1. Participants performed four maximal efforts to determine maximal peak torque. After 2 min rest, participants completed the all-out endurance test of 50 continuous eccentric repetitions. Data were gravity corrected and windowed to only include constant velocity periods. Repeated-measures analyses of variance were used to examine differences in maximal peak extension and flexion torque and the maximal torque measurement recorded during the endurance test. Absolute and relative reliability of the torque fatigue index, work fatigue index, and total work were assessed through calculation of intra-class correlation coefficients, coefficients of variation, and absolute 95% limits of agreement using the methods described by Bland and Altman (1986). Differences between the strength test and the endurance trial for peak torque were found to be non-significant for both quadriceps (323 vs. 323 N · m) and hamstrings (183 vs. 178 N · m). The intra-class correlation coefficients revealed significant (P<0.05) positive moderate to strong correlations (r=0.44–0.94) across repeated trials for all parameters except hamstring torque fatigue (P=0.11) and hamstring work fatigue index (P=0.08). Coefficients of variation ranged from 6% to 48% and were large for the work fatigue index and torque fatigue index but acceptable for total work for both the extensors and flexors. The 95% limits of agreement indicated systematic bias in repeated trials for both the work fatigue index and torque fatigue index for extensors and flexors, ranging from ?3% to ?10%, with less fatigue evident in the second test. There was also systematic bias for total work, with more work being performed during the second than the first test for both extensors and flexors. The random error was large for all variables and there was greater random error in the hamstrings compared with the quadriceps. Together with moderate to strong intra-class correlation coefficients and large coefficients of variation, the data suggest that there is small systematic bias in repeated eccentric muscle actions for both the quadriceps and hamstrings, although the random error was large despite habituation procedures. Therefore, data from an isokinetic eccentric muscle endurance task should be viewed with some caution even when participants receive considerable habituation before assessment.  相似文献   

Tool for Assessing Responsibility-Based Education (TARE): Instrument Development,Content Validity,and Inter-Rater Reliability     

Paul M. Wright  Mark W. Craig 《Measurement in physical education and exercise science》2013,17(3):204-219

Numerous scholars have stressed the importance of personal and social responsibility in physical activity settings; however, there is a lack of instrumentation to study the implementation of responsibility-based teaching strategies. The development, content validity, and initial inter-rater reliability testing of the Tool for Assessing Responsibility-Based Education (TARE) are described here. Inter-rater agreement was calculated for paired observations focused on 2 different teachers delivering a total of 18 separate physical education lessons for students in grades 1 through 6. Findings indicate that the Tool for Assessing Responsibility-Based Education provides scores with adequate inter-rater reliability. The procedures employed in this study proved feasible and enable observers to characterize the implementation of responsibility-based teaching in physical education. The Tool for Assessing Responsibility-Based Education has numerous research and training applications relative to the Teaching Personal and Social Responsibility model (Hellison, 2003 Hellison, D. 2003. Teaching responsibility through physical activity, 2nd, 15–38. Champaign, IL: Human Kinetics.  [Google Scholar]) and the national content standards for K–12 physical education, specifically Standard 5: Exhibits responsible personal and social behavior that respects self and others in physical activity settings (National Association for Sport and Physical Education, 2004 National Association for Sport and Physical Education (NASPE). 2004. Moving into the future. National standards for physical education, 2nd, 39–43. Reston, VA: Author.  [Google Scholar]).  相似文献   

Validity of an upper-body-mounted accelerometer to measure peak vertical and resultant force during running and change-of-direction tasks     

Daniel W.T. Wundersitz  Kevin J. Netto  Brad Aisbett  Paul B. Gastin 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(4):403-412

This study assessed the validity of a tri-axial accelerometer worn on the upper body to estimate peak forces during running and change-of-direction tasks. Seventeen participants completed four different running and change-of-direction tasks (0°, 45°, 90°, and 180°; five trials per condition). Peak crania-caudal and resultant acceleration was converted to force and compared against peak force plate ground reaction force (GRF) in two formats (raw and smoothed). The resultant smoothed (10 Hz) and crania-caudal raw (except 180°) accelerometer values were not significantly different to resultant and vertical GRF for all running and change-of-direction tasks, respectively. Resultant accelerometer measures showed no to strong significant correlations (r = 0.00–0.76) and moderate to large measurement errors (coefficient of variation [CV] = 11.7–23.9%). Crania-caudal accelerometer measures showed small to moderate correlations (r = ? 0.26 to 0.39) and moderate to large measurement errors (CV = 15.0–20.6%). Accelerometers, within integrated micro-technology tracking devices and worn on the upper body, can provide a relative measure of peak impact force experienced during running and two change-of-direction tasks (45° and 90°) provided that resultant smoothed values are used.  相似文献   

A linguistic dissociation in Williams syndrome: Good at gender agreement but poor at lexical retrieval     

Monnery  Sandrine  Seigneuric  Alix  Zagar  Daniel  Robichon  Fabrice 《Reading and writing》2002,15(5-6):589-612

Williams syndrome (WS) is a rareneuro-developmental disorder characterised byspared language in the face of serious deficitsin nonlinguistic cognitive abilities. Weconducted a study on ten WS individuals inwhich gender agreement and gender assignmentwere assessed by means of two tasks: gendercategorisation and gender concord. Subjectsperformed gender categorisation to real nounswhose gender was regular or exceptional giventheir ending, and to invented nouns which werecomposed of nonword or word stems and realword-endings. The same material was used in thegender concord task in which subjects had tomatch the items with the appropriate form ofthe article and the adjective carrying genderagreement. In the gender categorisation of realwords, WS were lower than controls but bothgroups demonstrated a similar sensitivity togender-ending regularities. In the gendercategorisation of nonwords, the results showeda clear dissociation. The WS subjects producedmore ending-consistent responses than thecontrols. Contrary to the controls, WS reliedheavily on the gender clue provided by theending even when the gender of the word evokedby the stem of the invented word was opposed tothat evoked by the ending. Participants with WSwere not influenced by the specific word evokedby the stem of the invented word. In the secondtask (concord task), the WS subjects performed well although lower than thecontrols. We concluded that the WS people werenot impaired in gender agreement which relieson syntactic rules and/or on the extraction ofregularities but experienced difficulties inretrieving lexical instances.  相似文献   

巴以和平进程的历史回顾与思考     

廖明华 《北京教育学院学报》2003,17(4):64-68

巴以冲突由来以久,这当中既牵涉到土地和经济利益问题,又有历史、文化和宗教诸方面的因素。以巴冲突表面上是以色列和巴勒斯坦之间的地区冲突,但其对中东地区乃至全世界的影响却非常深远。本文通过对以巴和平进程的历史回顾,指出以巴和平道路虽然问题纠葛,困难重重,但是和平终究会到来。巴勒斯坦人应当有其生存和建国的权利,但是巴勒斯坦的建国应当在联合国的协议框架内通过和平的方式实现。巴以双方应本着和平的愿望在充分认识历史和现实、充分认识双方实力的基础上真正进行和平谈判,在联合国的监督下实现和平共存。  相似文献   

WTO规则与中国网络著作权的法律保护     

宋才发 《商丘师范学院学报》2004,20(1):1-7

网络著作权是一个具有确定内涵的概念,网络著作权保护必须与TRIPS协定相一致。国外发达国家网络著作权立法的经验可资借鉴。必须依法维护国内外创作者的网络著作权,数字图书馆不能侵犯他人信息网络传播权。必须依法保护作者电子邮件的著作权,保护作者电子商务的著作权,依法规范广告商的网络广告行为。对于侵犯网络著作权案件要依法审判,审理网络著作权案件必须重视电子证据。利用互联网侵犯他人名誉权要承担法律责任。  相似文献   

基于LINUX路由器的校园网IP地址不足的解决方案   总被引：1，自引：0，他引：1  

刘国斌 《培训与研究》2006,23(2):43-45

本文为校园网中IP地址不足提供解决方案,更好地利用现有的IP资源,满足接入国际互联网的需求,为合理分配IP地址提出了解决方案:采用路由器软件共享IP地址,使局域网连接到国际互联网,并利用DHCP服务器动态分发IP地址,节省IP地址,提高IP地址的利用效率;这种方式充分利用有限的IP地址资源,使更多的计算机连接到国际互联网。  相似文献   

西学与中学 传统与现代－－解析王韬历史变易观的形成     

王守正 《廊坊师范学院学报》2001,17(1):56-59

王韬是中国近代社会第一位走向世界的历史学家，他既了解西方的文化，又自幼饱读中国古代经典；既受中国传统文化的影响，又清醒地认识到现实变革的势在必行。研究王韬历史变易观的形成，既要考察近代西学的影响，也不能忽视中国文化的作用；既要考虑其置身的积弱积贫的社会政治、经济环境，也不能无视中国文化传统的潜在激励。这两对看似矛盾、冲突的对立双方，实际上存在着可以沟通的桥梁。  相似文献   

浅谈英语语法形式和概念上的主谓语一致     

庞艳宏 《遵义师范学院学报》2001,3(3):58-59

在英语里,有关主语和谓语(动词)一致方面的问题非常复杂,学生很容易混淆不清.本文就自己在学习和教学中所接触的这一现象从语法形式和概念上作一些探讨.  相似文献