首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
基于因特网环境的CSCW中协同控制的研究,提出一个协同控制机制的概念模式,依此模式发展一个协同控制协议,实际应用于CSCW环境,使得在一个多用户信息共享环境中的群体合作能顺利进行,并增进了CSCW系统的协同程度和确保数据的一致性,发展成为一个可以应用于CSCW环境的协同控制协议.通过对该协同控制模式的研究结果,建立有实际应用目标的CSCW环境,推广到远程协作学习、协同设计、协同会诊、协同创作、群体决策等应用领域.  相似文献   

2.
M Ha  H Tokura  Y Yanai  T Moriyama  N Tsuchiya 《Ergonomics》1999,42(7):964-979
The present paper aimed at determining the combined effects of two different levels of air permeability and moisture absorption, in terms of clothing microclimate and subjective sensation, in resting and exercising subjects at an ambient temperature of 27 degrees C, a relative humidity of 50% and an air velocity of 0.14 m s-1. Three kinds of clothing ensemble were investigated: (1) polyester clothing with low moisture absorption and low air permeability (A), (2) polyester clothing with low moisture absorption and high air permeability (B), and (3) cotton clothing with high moisture absorption and high air permeability (C). The subjects exercised for 10 min on a cycle ergometer at an intensity of 30% maximal oxygen uptake and then had a 10 min rest. This sequence was repeated four times. The main findings are summarized as follows: (1) The clothing microclimate humidity in the back area was significantly higher in A than in B, and in C than in B. (2) The clothing microclimate temperature in the chest area was significantly higher in B than in A, and in B than in C. (3) The clothing microclimate temperature in the back area was significantly higher in C than in B. (4) The clothing surface temperature was significantly higher in C than in B. (5) Although the positive relationships between the microclimate humidity and forearm sweat rate was significantly confirmed in all three kinds of clothing, the microclimate humidity at chest for the same sweat rate was lower in C than in A and B. (6) Although the positive relationships between subjective sensation and forearm sweat rates were significantly confirmed in all three kinds of clothing, the subjective discomfort seemed to be reduced more effectively in C than in A and B for the same sweat rate. These results were discussed in terms of thermal physiology and combined effects of air permeability and moisture absorbency of the fabrics.  相似文献   

3.
李伟  柳长安  芦东昕  徐立峰 《微机发展》2006,16(11):109-111
Windows Mobile 5.0是微软为智能移动终端推出的软件平台,特别在智能手机领域受到越来越广泛的应用;在基于Windows Mobile的产品设计中,内存泄露又是需要考虑的关键之一。文中解析了Windows Mobile平台上监测设备内存泄露的工具AppVerifier,并在模拟器上实现了监测应用程序内存泄露,进而发现使用AppVerifier存在的问题,并指出了使用中高效利用AppVerifier的方法。  相似文献   

4.
The use of two-dimensional (2D) numerical simulations with a reduced particle-based Reynolds number (Re) for studying particle migration in a microchannel with equally spaced multiple constrictions was investigated. 2D and 3D colloidal lattice Boltzmann (LB) models were used to simulate particle-fluid hydrodynamics. Experiments were conducted with inert microparticles in a creeping flow in a microflow channel with symmetric wall obstacles. Lowering Re in 2D simulations by a factor of R (the dimensionless particle radius in LB simulations) resulted in a close match between numerically computed and experimentally obtained particle velocities, indicating that Re-based dimensional scaling was needed to capture the 3D particle flow dynamics in 2D simulations of experimental data. We captured particle displacement motion in a microchannel with symmetric inline obstacles in 2D simulations, where symmetry in the flow field was broken by local disturbances in the flow field due to particle motion, indicating that asymmetry in channel geometry is not the sole cause for particle displacement motion. Particle acceleration/deceleration around each constriction followed the same pattern, but each constriction acted like a particle accelerator in 2D and 3D simulations, in which particles exhibited progressively higher velocities in each subsequent constriction. Particles migrated across multiple streamlines in converging and diverging flow zones in a creeping flow, which calls into question the use of steady streamlines for calculating transient particle flow. Monotonicity in particle acceleration toward the constriction and deceleration beyond the constriction was broken by interparticle hydrodynamic interactions leading to more pronounced particle migration across multiple streamlines.  相似文献   

5.
The purpose of this introduction is to provide a brief overview of the articles in this special issue and also a framework for understanding, designing and evaluating strategies for co-operative learning in the workplace and in educational environments. The special edition is divided into two parts—Issue 1: Computer Supported Collaborative Learning in Formal Education, and Issue 2: Computer Supported Team and Organisational Learning in Workplaces. In general, Issue 1 focuses on collaborative learning in primary and secondary schools and in the University setting. Issue 2 is meant to focus on learning in complex and often highly stressful work situations which mostly require intensive communication in groups or teams and in each case allow for learning in the wider organisation. This introduction outlines a set of themes that can be found in the following papers and traces briefly how each paper fits within each discussion.  相似文献   

6.
本文阐述NDJCMT系统中词的自动切分技术, NDJCMT是我们实现的一个日汉机器翻译实验系统, 词的自动切分是日语词素分析、句法及语义分析的基础, 是一项日本语计算机信息处理的基础性研完课题, 它涉及对语言本身的研究。日语和汉语类似, 词及词之间无分隔符, 通常假名、汉字混写, 给词的切分造成了困难。作者根据日语的特点, 提出了一种“ 句节数最少” 词的自动切分方法, 使用语言编程且在一机上获得实现。  相似文献   

7.
《Ergonomics》2012,55(9):1317-1329
Hotness, weight, fitting problems etc., have been found to be the chief causes of the unpopularity of industrial safety helmets in tropical environments in developing countries (DC). Some selected safety helmets manufactured in industrialized countries (IC) were modified to provide extra head ventilation and to reduce weight, in order to make them more acceptable to users in hot environments. The modified helmets were subjected to ergonomics evaluation both objectively and subjectively in the laboratory (in simulated tropical conditions) as well as in the field situation. There was evidence that white helmets had some advantages in comfort, viz. reduction of hotness, compared to the other colours, e.g. red, green etc., when worn in the presence of radiant heat in the laboratory. Ventilation holes provided at the top of the shell seemed to reduce the greenhouse effect within the helmet shell which therefore felt less uncomfortable than a fully covered helmet. Even with a small reduction of weight, such as 45 g in helmets weighing about 350g, the difference in weight was perceived by the wearers. In adapting helmets made in IC for use in tropical climates, head ventilation and low weight perception are important aspects in comfort which need to be considered. In addition to low cost, a harness material suitable for sweat absorption is required. Adjustability and sizing to fit 90% of the user population also needs to be considered in the design and manufacture of safety helmets for people in DC.  相似文献   

8.
基于遥感与GIS的农村居民点景观特征比较   总被引:11,自引:0,他引:11  
以河北省阜平县、武邑县 ,福建省清流县、惠安县作为研究区 ,利用 2 0 0 0年 TM遥感图像 ,通过解译、判读得到景观结构矢量图 ,然后利用景观生态学数量方法分析了研究区农村居民点景观特征的差异及空间分布格局。研究表明 ,研究区农村居民点规模较小 ,平原地区平均面积不到 2 0 hm2 ,山区农村居民点平均面积低于 10 hm2。农村居民点距离较近 ,山区农村居民点平均距离小于 2 .5 km,平原地区农村居民点距离小于 0 .4 hm。农村居民点规模小 ,分布零散 ,适应于农业经济的发展。为了节约居民点用地 ,应采取加快城镇及中心村发展的方针 ,促进农村居民点布局的优化  相似文献   

9.
Abstract Studies undertaken in the UK and elsewhere have shown that secondary school pupils have difficulties in understanding certain theories in the physical sciences and, moreover, that certain conceptual problems in these areas may even persist among science students in higher education. The aims of this research project are to understand this process of conceptual change better, and to devise and test ways in which such a change can be promoted in classroom teaching programmes. Particular attention will be paid to the role that computer software tools can play in promoting such a change. The effectiveness of these software tools will be investigated in small-scale studies and in the context of classroom teaching. The findings will be made available to science teachers, teacher trainers and to those involved in educational software development.  相似文献   

10.
This study addresses the link between management concern for organizational crises and competitive strategy in small and medium‐sized enterprises in Peru, Mexico and the United States. Surveys were completed by 270 Peruvian, 218 Mexican and 256 American managers. Strategic orientation in Peru did not mirror the broad pattern found in Mexico and in the United States. Levels of concern for crises were significantly higher in both Mexico and Peru than in the United States for 12 of 21 crises. The level of concern for crises tended to increase with management level more in Mexico and Peru than in the United States. Correlations between competitive strategy and crisis concern were significant in 26 of 126 instances.  相似文献   

11.
This study evaluates empirically the proposition implicit in much recent gender and CMC research that expressions of gender distinctness among teens in online environments are becoming less frequent and less traditional. Gender preferences were analyzed in linguistic features and communication styles in synchronous text messages, along with self‐presentation in user profile pictures, drawing on data from popular English‐language teen chat sites collected in 2010. Significant differences were found in speech acts, message tone, and in physical stance, dress, and social distance in profile pictures that generally conform to traditional gender stereotypes. These findings are interpreted in light of previous gender and teen CMC research, adolescent development and socialization patterns, mass media representations, and trends towards media convergence in chat platforms.  相似文献   

12.
中国图形工程:2002   总被引:1,自引:7,他引:1       下载免费PDF全文
该文是关于中国图形工程的年度文献综述系列之八.为了让图形学及相关领域的理论研究和开发人员对图形学研究进展有一个全面了解以及为读者查阅相关文献提供方便.对2002年发表的有关计算机图形学领域的主要论文根据内容进行了分类,这些学术研究和技术应用论文(共计463篇)是从图形学论文发表比较集中的12种中文期刊(共计5423篇)上选取出来的.另外,还简要介绍了2002年在国内召开的与计算机图形学有关的会议情况.研究分析表明,国内这几年从事图形学及相关技术的研究开发人员不断增加,研究水平有很大提高,国内的学术交流也非常广泛,而图形学本身也在发展,与其他学科结合,又派生出一些新的研究方向.  相似文献   

13.
This paper shows a few possibilities for the application of Community OR in a Third World country based on experience in Venezuela. These possibilities are discussed in a framework of the relationship between the state and community organizations. Emphasis lies in showing that Community OR in Venezuela requires a deep critical commitment to emancipation in order to help community organizations develop in a rather hostile environment. Lastly, results in dealing with community organizations in Venezuela using the Interpretive Systemology approach are presented.  相似文献   

14.
结合具体院校的定位和就业市场调研与分析,确定了计算机软件技术专业的办学定位和人才特点,建立了"三维"的人才培养改革模型。在此基础上,构建了以"两大核心目标"为基础,以"五大模块"为核心的全新课程体系。阐述了以"四大实践平台"和"IT创新工作室"为主的人才培养模式的实践创新机制。该研究对地方本科院校的应用型人才培养具有实际应用。  相似文献   

15.
一种有效的实现分裂合并算法的数据结构   总被引:1,自引:0,他引:1       下载免费PDF全文
针对现有分裂合并分割算法数据结构存在的问题,本文设计了一种新的数据结构。这种数据结构能非常方便地实现分裂合并算法的每一步骤以及动态地分配内存,从而显著地减少了计算时间并在内存需求上有一定的改善。实验结果表明用这种数据结构实现分裂合并分割算法是有效的。  相似文献   

16.
《Ergonomics》2012,55(11):1629-1639
Questionnaire data captured in January–March 2007 were examined in relation to turnover in males and females during the next five years. In general, most of the workplace stressors (such as role conflict or peer support) were not antecedents of turnover in any group. Junior personnel with psychological strain in 2007 had an increased risk of turnover in the next five years. Low commitment to the service in 2007 increased the odds of turnover in male and female juniors and in female officers. Female juniors with less effective skills for coping with stress and who exercised less frequently on a weekly basis were more likely to leave. An incidental finding was that the odds of turnover were three times greater in female officers with children than in female officers with no children. Stress management interventions focusing on effective coping and sports and exercise participation which are targeted appropriately may improve retention.  相似文献   

17.
This study examined the covariability between interannual changes in the normalized difference vegetation index (NDVI) and actual evapotranspiration (ET). To reduce possible uncertainty in the NDVI time series, two NDVI datasets derived from Pathfinder AVHRR Land (PAL) data and the Global Inventory Monitoring and Modeling Studies (GIMMS) group were used. Analyses were conducted using data over northern Asia from 1982 to 2000. Interannual changes over 19 years in the PAL-NDVI and GIMMS-NDVI were compared with interannual changes in ET estimated from model-assimilated atmospheric data and gridded precipitation data. For both NDVI datasets, the annual maximum correlation with ET occurred in June, which is the beginning of the vegetation growing season. The PAL and GIMMS datasets showed a significant, positive correlation between interannual changes in the NDVI and ET over most of the vegetated land area in June. These results suggest that interannual changes in vegetation activity predominantly control interannual changes in ET in June. Based on analyses of interannual changes in temperature, precipitation, and the NDVI in June, the study area can be roughly divided into two regions, the warmth-dominated northernmost region and the wetness-dominated southern region, indicating that interannual changes in vegetation and the resultant interannual changes in ET are controlled by warmth and wetness in these two regions, respectively.  相似文献   

18.
An evaluation study was conducted to investigate the effect of the use of a computer-supported cognitive tool (CT) in the one-to-one classroom setting on student engagement, attainment and perceptions in learning common fractions. Two Primary 4 classes with 68 students participated in this study based on 11 teaching sessions lasting 455 min in total. The students in the experimental group learned the target topic with the use of CT in a one-to-one classroom, while the students in the control group learned the target topic under the traditional teaching approach. The results of a time allocation analysis showed that the use of CT in a one-to-one classroom enhanced student engagement in terms of time-on-task for learning exploration during class time. The results of the post-attainment test indicated that students in the experimental group performed better than those in the control group. Moreover, the questionnaire survey results indicated that students liked to learn the target topic with the use of CT in a one-to-one classroom. This study reveals the potential of the use of CT in a one-to-one classroom to promote classroom-based dialogic interaction in mathematics lessons. It also implies a need for a longitudinal study to investigate suitable pedagogical designs for the use of CT for promoting knowledge transfer in learning challenging mathematics topics.  相似文献   

19.
Manufacturing industry is going through a period of unprecedented change as a result of the developments in micro-electronic technology. This is bringing about a transformation not only in hardware, in the form of computer-aided manufacturing, but in the manner in which production is organised and controlled.It is in the latter connection that the present paper sets out to review current developments and future trends. In particular the machine readable bar-code is seen as a key element in extending computerised control to cover not only the machines, but tools, materials and parts and their movement in the development of fully integrated manufacturing systems.As the move towards automation gathers pace it is forecast that manufacturing industry will become more process industry like in form, with consequences for the way in which production is organised and controlled.Finally consideration is given to the manner in which these current developments in the field of production are giving rise to a structural alteration in industrial labour requirements in which, in the future, fewer people will be required but on highly enriched work tasks.  相似文献   

20.
This study focuses on older adults’ finger-based text entry on smartphones and tablets. Thirty-two older adults entered Chinese characters with two input methods (typing and handwriting) on touch screens with four display sizes (3.5 in., 5 in., 7 in., 9.7 in.). Their performance, acceptance, preference, and errors were recorded and thus four findings were found. First, on small displays (3.5 in. and 5 in.), handwriting contributed to shorter task completion time, higher perceived ease of use, and higher usage intention than typing, but no difference was observed on large displays (7 in. and 9.7 in.). Second, there is a gap of task completion time and perceived ease of use between 5 in. and 7 in. for typing, whereas there is no gap for handwriting. Third, participants’ preference of 9.7 in. was almost the same as that of 7 in., and their preference of 7 in. was 1.5 times as strong as that of 5 in. Fourth, participants’ finger-based text entry was prone to 13 types of errors. Many of these errors were caused by the mismatch between older adults’ mental models and designers’ mental models.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号