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1.
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   

2.
Multi-disciplinary software interoperability in the Architecture, Engineering, Construction and Operations industry is becoming a new and widely adopted business culture. Technical advances in interoperability architectures, frameworks, methods and standards during the last decade resulted in higher maturity of product and process models. Mature models, in effect, enable data exchange by an increasing number of software applications in the industry. This establishes trust in data exchange and results in the lower cost impact of inefficient interoperability. The negative cost impact increases with advancing life-cycle phase, from planning and design phase to construction phase and to operation and maintenance phase. Interoperability in the planning and design phase is most mature and well published, while interoperability in the construction phase and for automated manufacturing is less researched. This paper reviews state-of-the art automated manufacturing systems in construction and researches interoperability requirements for automated construction in context of the entire building lifecycle. Our research is based on experimental free-form clay building, designed with embedded simple HVAC components, and manufactured with additive layer technology. Conclusions provide valuable results for interoperability research and practice in construction projects with automated manufacturing systems in place.  相似文献   

3.
This research compared social networking site (SNS) use in a collectivistic culture, China, and an individualistic culture, the United States (US). Over 400 college student participants from a Southwestern University in Chongqing, China, and 490 college participants from a Midwestern University in the US completed a survey about their use of SNSs – time spent, importance and motives for use. They then rated themselves on a variety of personal characteristics, namely the Big Five Personality factors, Loneliness, Shyness and Life Satisfaction. Results revealed cultural differences in SNS use. US participants spent more time in SNS, considered them to be more important and had more friends in SNSs than did Chinese participants. Self-ratings of personal characteristics also differed in the two cultures as did the personal characteristics that predicted SNS use. In general, personal characteristics were less effective in predicting SNS use in China than in the US. Findings suggest that in collectivistic cultures the importance of the family, friends and one’s groups may be partly responsible for Chinese participants’ lesser use of SNSs, whereas in individualistic cultures the importance of self and having more but less close and enduring friendships may be partly responsible for US participants’ greater use of SNSs. Personal characteristics predicted SNS use in both cultures but were stronger predictors in an individualistic culture than in a collectivistic, consistent with the emphasis on self in the former and on family, friends and one’s groups in the latter. Future research is needed to identify whether cultural values always take precedence over personal characteristics and motives in determining behavior in the virtual world.  相似文献   

4.
Collaboration between industry and academia supports improvement and innovation in industry and helps to ensure industrial relevance in academic research. However, many researchers and practitioners believe that the level of joint industry–academia collaborations (IAC) in software engineering (SE) is still relatively very low, compared to the amount of activity in each of the two communities. The goal of the empirical study reported in this paper is to characterize a set of collaborative industry–academia R&D projects in the area of software testing conducted by the authors (based in Canada and Turkey) with respect to a set of challenges, patterns and anti-patterns identified by a recent Systematic Literature Review study, with the aim of contributing to the body of evidence in the area of IAC, for the benefit of SE researchers and practitioners in conducting successful IAC projects in software testing and in software engineering in general. To address the above goal, a pool of ten IAC projects (six completed, two failed and two ongoing) all in the area of software testing, which the authors have led or have had active roles in, were selected as objects of study and were analyzed (both quantitatively and qualitatively) with respect to the set of selected challenges, patterns and anti-patterns. As outputs, the study presents a set of empirical findings and evidence-based recommendations, e.g.: it has been observed that even if an IAC project may seem perfect from many aspects, one single major challenge (e.g., disagreement in confidentiality agreements) can lead to its failure. Thus, we recommend that both parties (academics and practitioners) consider all the challenges early on and proactively work together to eliminate the risk of challenges in IAC projects. We furthermore report correlation and interrelationship of challenges, patterns and anti-patterns with project success measures. This study hopes to encourage and benefit other SE researchers and practitioners in conducting successful IAC projects in software testing and in software engineering in general in the future.  相似文献   

5.
This research evaluates the effectiveness of the Interactive White Board Technology (IWBT) in teaching in the Faculty of Information Technology (FIT) in UAE University. IWBT includes integrated hardware and software components to facilitate teaching process and hence, provides rich and interactive experience for both teachers and students. However, the IWBT is recent and issues emanating from its use in teaching and learning are scant and inconclusive. The research developed a theoretical framework to guide the research endeavor. Accordingly, the research attempted to unveil factors influencing IWBT introduction and use in different departments within FIT. The research findings reported different hurdles facing the integral use of IWBT in teaching in FIT. The research also suggested that the IWBT could be useful in teaching technical courses in FIT. This is contingent upon addressing certain factors highlighted in this research. This research introduces different recommendations to further IWBT use in FIT. The research highlights different theoretical and professional contributions and contentions and raises the need for more research in the IWBT field.  相似文献   

6.
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   

7.
Granular Computing and Knowledge Reduction in Formal Contexts   总被引:6,自引:0,他引:6  
Granular computing and knowledge reduction are two basic issues in knowledge representation and data mining. Granular structure of concept lattices with application in knowledge reduction in formal concept analysis is examined in this paper. Information granules and their properties in a formal context are first discussed. Concepts of a granular consistent set and a granular reduct in the formal context are then introduced. Discernibility matrices and Boolean functions are, respectively, employed to determine granular consistent sets and calculate granular reducts in formal contexts. Methods of knowledge reduction in a consistent formal decision context are also explored. Finally, knowledge hidden in such a context is unraveled in the form of compact implication rules.  相似文献   

8.
For many years, the author has been involved in teaching and research in the use of Operations Research as a tool of analysis to study food security problems in sub‐Saharan Africa, in particular, grass root problems of poor farmers. The paper presents an introduction to the way Operations Research methods have been applied in case studies and research projects, and discusses in retrospect the author's views on the strengths and limitations of the application of Operations Research. The paper has in particular been written for people who are not familiar with applications of Operations Research in agriculture, and are interested to learn about its potential usefulness in practice. The retrospective part is largely based on food security studies in e.g. Tanzania, Burkina Faso, Bénin, Togo and Eritrea and on participation in several interdisciplinary research programmes in Africa.  相似文献   

9.
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   

10.
在本文中,我们给出了在结构与随机扰动下的动态大系统的稳定性分析,建立了这类大系统的依概率吸引性,依概率一致有界性,依概率大范围渐近稳定性,p吸引性,一致p有界性,和大范围渐近p稳定性的结论。这些结论的假设是由孤立子系统和与其联系的李亚普诺夫函数,受扰系统的结构和作用在子系统上的随机扰动表出的。  相似文献   

11.
邱继红  刘凯 《控制工程》2000,7(5):13-15
针对由多台机器人及多种辅助设备组成的冲压自动生产线编程量大、运动协调关系复杂、联锁信号多的特点 ,介绍一种离线规划与在线示教相结合的冲压机器人示教编程方法 ,对冲压机器人进行运动轨迹、作业内容等方面的示教 ,降低了示教内容的复杂性 ,节省了在线示教所占用的现场调试和生产时间。  相似文献   

12.
Abstract

This paper describes some trends and issues in the application of information technology in organisations. Technology trends are outlined in the areas of computing power, telecommunications, networking, software and standards. Some trends in the applications of IT are described with respect to developments in information systems and office automation. Some differences in the likely role of IT in the industrialised and developing countries are discussed. The second half of the paper deals with issues in the management of IT applications in organisations, and issues are identified as being political, organisational and social in nature in addition to technical. A social systems framework is proposed for the analysis of these issues. Some specific IT issues are then discussed involving alternative stakeholder perspectives, the analysis of decision making processes, the process of consultation and communication and the organisational impacts of IT applications.  相似文献   

13.
王琳  毕艳 《图学学报》2019,40(1):207
针对判别直线与平面相交及平面与平面相交的可见性提出了一种假想墙的方法。 在直线与平面相交问题中探讨了 3 种典型的情况:一般位置直线与特殊位置平面相交、一般位 置直线与一般位置平面相交、特殊位置直线与一般位置平面相交;在平面与平面相交的问题中 探讨了 3 种典型的情况:特殊位置平面与特殊位置平面相交、一般位置平面与特殊位置平面相 交、一般位置平面与一般位置平面相交。通过假想墙方法,可快速准确地判断直线与平面相交 及平面与平面相交的可见性,为机械制图课程相关内容的学习及教学提供一些参考。  相似文献   

14.
《Ergonomics》2012,55(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 °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   

15.
There are unique challenges in managing data collection and management from instruments in the field in general. These issues become extreme when “in the field” means “in a plane over the Antarctic”. In this paper we present the design and function of the Forward Observer a computer cluster and data analysis system that flies in a plane in the Arctic and Antarctic to collect, analyze in real time, and store Synthetic Aperture Radar (SAR) data. SAR is used to analyze the thickness and structure of polar ice sheets. We also discuss the processing of data once it is returned to the continental US and made available via data grids. The needs for in-flight data analysis and storage in the Antarctic and Arctic are highly unusual, and we have developed a novel system to meet those needs.We describe the constraints and requirements that led to the creation of this system and the general functionality which it applies to any instrument. We discuss the main means for handling replication and creating checksum information to ensure that data collected in polar regions are returned safely to mainland US for analysis. So far, not a single byte of data collected in the field has failed to make it home to the US for analysis (although many particular data storage devices have failed or been damaged due to the challenges of the extreme environments in which this system is used).While the Forward Observer system is developed for the extreme situation of data management in the field in the Antarctic, the technology and solutions we have developed are applicable and potentially usable in many situations where researchers wish to do real time data management in the field in areas that are constrained in terms of electrical supply.  相似文献   

16.
生物组织光声成像技术综述   总被引:1,自引:0,他引:1  
光声成像是一种低功率、非电离的成像方式,既具有声学方法对深层组织成像分辨率高的优点,又具有光学方法在功能成像、分子成像方面具有高对比度的优势。本文回顾了近年来,光声成像技术在生物医学领域的研究进展,介绍了光声成像的基本成像原理。以此为基础,本文介绍了光声成像的两种主要成像方案:光声断层成像和光声显微镜,并且讨论了光声成像在获取生物组织化学成分信息和微结构信息方面的优越性;最后,本文对光声成像技术的优点和应用前景进行了总结。  相似文献   

17.
A multi-year study was carried out to evaluate ERS synthetic aperture radar (SAR) imagery for monitoring surface hydrologic conditions in wetlands of southern Florida. Surface conditions (water level, aboveground biomass, soil moisture) were measured in 13 study sites (representing three major wetland types) over a 25-month period. ERS SAR imagery was collected over these sites on 22 different occasions and correlated with the surface observations. The results show wide variation in ERS backscatter in individual sites when they were flooded and non-flooded. The range (minimum vs. maximum) in SAR backscatter for the sites when they were flooded was between 2.3 and 8.9 dB, and between 5.0 and 9.0 dB when they were not flooded. Variations in backscatter in the non-flooded sites were consistent with theoretical scattering models for the most part. Backscatter was positively correlated to field measurements of soil moisture. The MIchigan MIcrowave Canopy Scattering (MIMICS) model predicts that backscatter should decrease sharply when a site becomes inundated, but the data show that this drop is only 1-2 dB. This decrease was observed in both non-wooded and wooded sites. The drop in backscatter as water depth increases predicted by MIMICS was observed in the non-wooded wetland sites, and a similar decrease was observed in wooded wetlands as well. Finally, the sensitivity of backscatter and attenuation to variations in aboveground biomass predicted by MIMICS was not observed in the data.The results show that the inter- and intra-annual variations in ERS SAR image intensity in the study region are the result of changes in soil moisture and degree of inundation in the sites. The correlation between changes in SAR backscatter and water depth indicates the potential for using spaceborne SAR systems, such as the ERS for monitoring variations in flooding in south Florida wetlands.  相似文献   

18.
The objective of this study was to assess the relationships between physical and psychosocial work exposures, engagement in domestic work and work-home imbalance in relation to symptoms of musculoskeletal disorders and emotional exhaustion in white- and blue-collar men and women. Three thousand employees from 21 companies were asked to answer a questionnaire on family structure, household and child care tasks, work exposure, work-home imbalance and symptoms of neck/shoulder disorders, low back disorders and emotional exhaustion. Women reported more musculoskeletal disorders and engagement in domestic work. Adverse at-work exposures were highest in blue-collar women. High engagement in domestic work was not separately associated with symptoms but paid work exposure factors were associated. High engagement in domestic work interacted with adverse work exposure and increased risk estimates for low back disorders and emotional exhaustion. Reported work-home imbalance was associated with neck/shoulder disorders in women and with emotional exhaustion in both women and men. PRACTITIONER SUMMARY: The current article adds to earlier research by showing that high engagement in domestic work is not separately associated with increased symptoms, but interacts with psychosocial work exposure variables to produce emotional exhaustion in both women and men and low back disorders in women.  相似文献   

19.
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   

20.
Data on health and lifestyle from the Naval service cohort study of occupational stress form the background to a discussion of employee health and the sustainability of a healthy workforce in relation to secular changes – in particular, the increasing prevalence of obesity. One thousand two hundred and forty-one Naval personnel returned questionnaires in 2007 and 2011 and reported their body mass index (BMI), alcohol consumption and smoking, general health and health conditions such as back pain and high blood pressure on both occasions. Health risk due to high BMI and waist circumference in 2011 was predicted by low participation in exercise in 2007. Those performing physically demanding work in 2007 were more likely to be in the ‘no risk’ category in 2011. High BMI in 2007 was associated with the development of back pain, musculoskeletal conditions and high blood pressure in 2011. The findings are discussed in relation to two aspects of sustainability: the sustainability of current ergonomics practice in relation to health and safety; and the role of ergonomics in sustaining a healthy and productive workforce.

Practitioner Summary: Evidence is presented for the benefits of exercise in sustaining employee health and for an association between a high BMI and a number of common health complaints that have traditionally been tackled through workplace ergonomics. This evidence can be used to support the development of workplace design concepts that promote physical activity.  相似文献   

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