基于用户相似度的协同过滤推荐算法简

协同过滤推荐算法通过研究用户的喜好,实现从海量数据资源中为用户推荐其感兴趣的内容,在电子商务中得到了广泛的应用。然而,当此类算法应用到社交网络时,传统的评价指标与相似度计算的重点发生了变化,从而出现推荐算法效率偏低,推荐准确度下降问题,导致社交网络中用户交友推荐满意度偏低。针对这一问题,引入用户相似度概念,定义社交网络中属性相似度,相似度构成与计算方法,提出一种改进的协同过滤推荐算法,并给出推荐质量与用户满意度评价方法。实验结果表明：改进算法能有效改善社交网络中的推荐准确性并提高推荐效率,全面提高用户满意度。     

一种结合特征相关的软件质量研究

首先分析了目前常用的软件质量提高方法及评估标准,结合各种方法的优缺点,提出用户满意度和可靠性是软件成功的两个重要问题.首次提出特征因子的概念,并首次尝试借助神经网络通过特征因子对软件项目进行分析,并得出影响软件工程的影响度.其结论比较符合实际,为提高软件质量提供了一个可参考的方法.     

Residential mobility of low-income,subsidized households: a synthesis of explanatory frameworks

Mobility, residential quality, and life outcomes are linked in the literature and these relationships have influenced low-income housing policy. This research investigates the determinants of mobility for households with a federal housing subsidy. Combining unique data from a survey of Housing Choice Voucher households, client program files, and secondary data, this study uses logistic regression to test several explanations for mobility, including the life cycle, housing market perceptions, and perceived and actual neighborhood conditions. The results indicate that a synthesis of explanations produce the best model to predict residential mobility. Neighborhood quality, perceived and actual, variables most strongly influence mobility, but life cycle factors and perception of the local housing market also impact moving choices. At the same time, the results suggest a gap in our understanding of the relationship among individuals’ environmental perceptions, formation of feelings of neighborhood satisfaction, and actual neighborhood conditions. The article concludes with a discussion of the research and policy implications from this study.     

Does office space occupation matter? The role of the number of persons per enclosed office space,psychosocial work characteristics,and environmental satisfaction in the physical and mental health of employees

The study examined the effects of office space occupation, psychosocial work characteristics, and environmental satisfaction on physical and mental health of office workers in small‐sized and open‐plan offices as well as possible underlying mechanisms. Office space occupation was characterized as number of persons per one enclosed office space. A total of 207 office employees with similar jobs in offices with different space occupation were surveyed regarding their work situation (psychosocial work characteristics, satisfaction with privacy, acoustics, and control) and health (psychosomatic complaints, irritation, mental well‐being, and work ability). Binary logistic and linear regression analyses as well as bootstrapped mediation analyses were used to determine associations and underlying mechanisms. Employee health was significantly associated with all work characteristics. Psychosocial work stressors had the strongest relation to physical and mental health (OR range: 1.66–3.72). The effect of office space occupation on employee health was mediated by stressors and environmental satisfaction, but not by psychosocial work resources. As assumed by sociotechnical approaches, a higher number of persons per enclosed office space was associated with adverse health effects. However, the strongest associations were found with psychosocial work stressors. When revising office design, a holistic approach to work (re)design is needed.     

Effectiveness of daylighting design and occupant visual satisfaction in a LEED Gold laboratory building

Using daylight as primary light source has been widely recognized as an important strategy to reduce building energy demand and enhance indoor environment quality. However, to design and operate a building to make full use of daylight, which is a dynamic light source, to meet diverse occupant needs remains a challenge. This paper reports a post-occupancy study of the visual environment in a laboratory building on a university campus, and puts a spotlight on the building occupants as it examines the effectiveness of the daylighting design and systems integration in creating a visual environment to support occupant comfort and satisfaction while reducing artificial lighting demand. Results show generally high satisfaction with daylit work environment and positive effect of the horizontal shading strategy. Issues about the integration between daylighting and electric lighting systems and level of occupant control are identified and discussed for improving the effectiveness of daylighting and enhancing the quality of the visual environment in the building of study. A multiple-tool methodology is developed and tested, which included occupant surveys, interviews, illuminance measurements, continuous data loggers, fisheye-lens camera and glare-identifying software, and documentation of spatial settings, systems features, and user behavior.     

A Study of Online Portal Users’ Loyalty From Core Service,Additional Value-added Service and Switching Barriers Perspectives

This study proposes a research model elucidating the effects of core service satisfaction, additional value-added service satisfaction, and switching barriers as determinants of portal loyalty and tests the model using empirical data collected from game portal users. The results suggest that different service satisfaction and switching barriers are strong antecedents of p-loyalty; the moderating effect of switching barriers on the relationship between satisfactions and p-loyalty is contingent on the portal users’ usage patterns.     

Getting off on the right foot: Subjective value versus economic value in predicting longitudinal job outcomes from job offer negotiations.

Although negotiation experiences can affect a negotiator's ensuing attitudes and behavior, little is known about their long-term consequences. Using a longitudinal survey design, the authors tested the degree to which economic and subjective value achieved in job offer negotiations predicts employees' subsequent job attitudes and intentions concerning turnover. Results indicate that subjective value predicts greater compensation satisfaction and job satisfaction and lower turnover intention measured 1 year later. Surprisingly, the economic outcomes that negotiators achieved had no apparent effects on these factors. Implications, limitations, and future directions are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Life satisfaction and self-reported problems after spinal cord injury: Measurement of underlying dimensions.

Objective: Evaluate the utility of the current 7-scale structure of the Life Situation Questionnaire—Revised (LSQ–R) using confirmatory factor analysis (CFA) and explore the factor structure of each set of items. Design: Adults (N = 1,543) with traumatic spinal cord injury (SCI) were administered the 20 satisfaction and 30 problems items from the LSQ–R. Results: CFA suggests that the existing 7-scale structure across the 50 items was within the acceptable range (root-mean-square error of approximation [RMSEA] = 0.078), although it fell just outside of this range for women. Factor analysis revealed 3 satisfaction factors and 6 problems factors. The overall fit of the problems items (RMSEA = 0.070) was superior to that of the satisfaction items (RMSEA = 0.80). RMSEA fell just outside of the acceptable range for Whites and men on the satisfaction scales. All scales had acceptable internal consistency. Conclusion: Results suggest the original scoring of the LSQ–R remains viable, although individual results should be reviewed for special population. Factor analysis of subsets of items allows satisfaction and problems items to be used independently, depending on the study purpose. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Moving toward more perfect unions: Daily and long-term consequences of approach and avoidance goals in romantic relationships.

In 2 daily experience studies and a laboratory study, the authors test predictions from approach-avoidance motivational theory to understand how dating couples can maintain feelings of relationship satisfaction in their daily lives and over the course of time. Approach goals were associated with increased relationship satisfaction on a daily basis and over time, particularly when both partners were high in approach goals. Avoidance goals were associated with decreases in relationship satisfaction over time, and people were particularly dissatisfied when they were involved with a partner with high avoidance goals. People high in approach goals and their partners were rated as relatively more satisfied and responsive to a partner's needs by outside observers in the lab, whereas people with high avoidance goals and their partners were rated as less satisfied and responsive. Positive emotions mediated the link between approach goals and daily satisfaction in both studies, and responsiveness to the partner's needs was an additional behavioral mechanism in Study 2. Implications of these findings for approach-avoidance motivational theory and for the maintenance of satisfying relationships over time are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early traces of usability as a science and as a profession

Shackel’s paper [Shackel, B., 1991. Usability – context, framework, definition, design and evaluation. In: Shcakel, B., Richardson, S. (Eds.), Human Factors for Informatics Usability. Cambridge University Press, Cambridge, UK] is reviewed in an attempt to assess his contribution to the development of usability as a science and as a profession. Usability related research is first situated in the period around 1990. The contributions to usability as a science then are addressed via Professor Shackel’s definition and evaluation of usability. Finally, his contribution toward usability as a profession is acknowledged via his view of usability in the light of wider business goals.