循环赛日程表的递归和非递解

介绍了算法设计技术分治法的应用。使用分治法实现了循环赛日程表的递归和非递归解,并作了较为详细的说明,供《算法设计与分析》课程教学参考。     

A new framework for understanding educational digital library use: re-examining digital divides in U.S. schools

Despite their decade of deployment, educational digital libraries have not achieved sustained use in elementary and secondary schools in the United States. Barriers to accessing the Internet and computers have been widely targeted by myriad initiatives, but efforts aimed at bridging this first-level “digital divide” have not led to increased use of the Internet and digital library resources in U.S. classrooms. In fact, such programs have revealed additional divides that affect educators’ use. This paper examines the additional digital divide levels and proposes a new framework for understanding technology innovation in schools that can improve development and outreach approaches by digital library developers.     

分布式环境下的并行处理ARC／INFO飞行动画生成技术

针对ARC／INFO系统中飞行动画生成速度慢的问题,分析了速度慢的原因,提出了用并行处理技术来加速的思想,设计了相应的并行算法,并在cluster结构上实现了飞行动画生成并行处理,经实际应用达到了提高计算速度,满足实时性要求的目的。     

蒲石河抽水蓄能电站上库分水岭渗漏分析

蒲石河抽水蓄能电站上库为天然库盆,水库渗漏问题是主要工程地质问题之一。分析与研究库周总长为3 700.2 m库岸分水岭的渗漏问题后认为,长约846 m的北库岸水库蓄水后库水外渗的可能性不大;西、南库岸地段水力坡降增大,渗径较短,渗流量增大;西库岸存在沿F1、Fy3、F103等断层破碎带渗漏通道的地质条件;上水库总渗漏为3 413.89 m3/d。渗漏分析大体上能够反映实际情况,但有些问题仍需进一步研究。     

Profiling the non-users: Examination of life-position indicators,sensation seeking,shyness, and loneliness among users and non-users of social network sites

The aim of the current study is to explore if there are differences between users and non-users of social network sites in terms of their sensation seeking, life-position indicators, shyness, and loneliness. Using data from a survey of adults 19–76 years old, results revealed that compared to an average Facebook user, a non-user is significantly older and scores higher on shyness and loneliness, is less socially active, and less prone to sensation seeking activities. Facebook is not a substitute channel of communication for those who are shy and lonely and lack face-to-face interactions. This study extends our knowledge of digital divide, uses and gratifications theory, and social enhancement hypothesis.     

Does technology empower urban youth? The relationship of technology use to self-efficacy

Many propose technology as a tool for empowerment of lower SES urban students, but little research has investigated the relationship between technology and empowerment for this population. We investigate how different aspects of technology use and ownership could empower urban youth through increasing their self-efficacy. Instead of simply a general measure of self-efficacy, we focus on several important domains related to STEM (Science, Technology, Engineering, and Mathematics) subjects including technological, mathematics/science, academic, and general self-efficacy. Our investigation incorporates many aspects of technology use by considering first level digital divide characteristics, such as ownership and total amount of use, and second level digital divide characteristics, such as specific communication, multimedia, content creation, and social networking activities. We use a unique survey of fourth and fifth grade students who were given a laptop, thereby controlling for the typical disparity in computer ownership and access among lower SES students. We found that technology use influences each domain of efficacy in specific ways, indicating the importance of considering multiple domains of self-efficacy. Most notably, frequency of communication and especially frequency of email use related to all four domains of efficacy and frequency of playing games related to general, mathematics/science, and academic efficacy. However, social networking activities had a negative association with academic and general efficacy. We conclude by considering the importance of multiple domains in self-efficacy research and policy implications for students and their schools.     

Digital neighborhoods

With the advent of ‘big data’ there is an increased interest in using social media to describe city dynamics. This paper employs geo-located social media data to identify ‘digital neighborhoods’ – those areas in the city where social media is used more often. Starting with geo-located Twitter and Foursquare data for the New York City region in 2014, we applied spatial clustering techniques to detect significant groupings or ‘neighborhoods’ where social media use is high or low. The results show that beyond the business districts, digital neighborhoods occur in communities undergoing shifting socio-demographics. Neighborhoods that are not digitally oriented tend to have higher proportion of minorities and lower incomes, highlighting a social–economic divide in how social media is used in the city. Understanding the differences in these neighborhoods can help city planners interested in generating economic development proposals, civic engagement strategies, and urban design ideas that target these areas.     

Understanding e‐Government portal use in rural India: role of demographic and personality characteristics

Electronic government (e‐Government) is one of the most important ways to bridge the digital divide in developing countries. We develop a model of e‐Government portal use. We use various individual characteristics, namely demographics and personality, as predictors of e‐Government portal use. Specifically, our predictors were (1) gender, age, income and education; (2) the Big Five personality characteristics, i.e. extraversion, neuroticism, conscientiousness, agreeableness and openness to experience; and (3) personal innovativeness with information technology. We conducted a field study in a village in India. We collected data from over 300 heads of household. We found support for our model, with most variables being significant and explaining 40% of the variance in e‐Government portal use.     

浅析热媒脱水和脱轻馏分的优化方式

长输管道输送原油需要加热.阐述了新型原油加热系统热媒脱水、脱轻馏分的工艺,针对用户在使用热媒炉系统过程中易发生水击,无法实现自动控制和优化运行,热效率低,热媒乳化失效快等问题进行了攻关,发现主要根源是热媒脱水、脱轻馏分工艺操作不合理造成的.经过长期的实验,得出了热媒脱水和脱轻馏分的优化曲线,实现了热媒炉系统的安全、平稳、高效运行.     

数据可视化及其在地学中的应用

数据可视化是将多维数据以图形、图像方式显示,拓宽了传统图标的功能,提高了人们对数据的处理及解释能力,为更好地利用数据奠定了基础。数据可视化已经应用于处理地学数据,并且应用各种语言开发出了多种数据可视化技术。本文简要地介绍了数据可视化及其在地学中的应用,并结合实例介绍了其实现语言OpenGL、实现技术分治技术。指出开发四维及四维以上图形显示技术是可视化研究的难点。