一种改进的基于Delaunay三角网的聚类算法

Mundur等提出了一种基于Delaunay三角网的聚类算法,并将其应用于视频帧的多维特征数据的聚类以生成视频摘要,取得了较好的效果。但是,该算法计算量太大,导致效率不高。为提高该算法的效率,以适合于对大数据集的处理,提出了一种改进的基于Delaunay三角网的聚类算法。通过在典型数据集上的实验,提出了一种新的确定全局聚类阈值的方法,使得计算量大为减少。实验结果表明,该算法无需用户提供聚类参数,也能得到良好的聚类结果,因此能够实现聚类过程自动化;并且计算速度更快,效率更高,适合于大数据集的处理。     

彬长矿区4号煤层煤质特征及洁净等级划分

为实现彬长矿区优质煤炭资源的清洁高效利用,在对彬长矿区以往勘查钻孔的煤质化验资料统计分析的基础上,系统分析了该矿区主采煤层4号煤的煤岩、煤质特征,论述了硫分、灰分、挥发分、发热量和有害微量元素的分布规律,依据最新煤炭资源潜力评价提出的煤炭洁净等级6级划分方案,选用灰分、硫分、有害元素(F、Cl、As及Pb)6个评价指标对矿区内4号煤层的煤炭资源洁净等级进行了初步划分。彬长矿区4号煤层以低硫、低中灰、中高挥发分、特高热值不黏煤为主,局部含小范围的弱黏煤,彬长矿区4号煤层原煤洁净等级为Ⅲ级,属较好洁净煤;浮煤洁净等级为Ⅱ级,属好洁净煤。整个矿区内4号煤层原煤洁净等级以Ⅲ级较好洁净煤为主,分布区占矿区面积的73.03%,仅在矿区西部洪家镇—巨家镇一带和中东部出现小范围的Ⅳ级中等洁净煤分布区,面积占比为26.97%。     

加工煤矿井筒罐道木的简易刨床

每次更换罐道木之前都会提前对罐道木进行加工,但是井筒罐道木的加工制作非常困难,不仅劳动强度大,而且效率低。为此,研制了以台式刨床刨头为主刀具,锥形伞齿轮传动为主传动系统,配有木料长形底托架、尺寸精度调节装置、线缆拖动装置的加工罐道木的简易龙门刨床,应用实践效果很好。     

Computational approaches to subjectivity and sentiment analysis: Present and envisaged methods and applications

Recent years have witnessed a surge of interest in computational methods for affect, ranging from opinion mining, to subjectivity detection, to sentiment and emotion analysis. This article presents a brief overview of the latest trends in the field and describes the manner in which the articles contained in the special issue contribute to the advancement of the area. Finally, we comment on the current challenges and envisaged developments of the subjectivity and sentiment analysis fields, as well as their application to other Natural Language Processing tasks and related domains.     

Monitoring,Warning, and Control of Rockburst in Deep Metal Mines

This paper reviews the recent achievements made by our team in the mitigation of rockburst risk. It includes the development of neural network modeling on rockburst risk assessment for deep gold mines in South Africa, an intelligent microseismicity monitoring system and sensors, an understanding of the rockburst evolution process using laboratory and in situ tests and monitoring, the establishment of a quantitative warning method for the location and intensities of different types of rockburst, and the development of measures for the dynamic control of rockburst. The mitigation of rockburst at the Hongtoushan copper mine is presented as an illustrative example.     

Exploring regulatory processes during a computer-supported collaborative learning task using process mining

The purpose of this study was to explore sequences of social regulatory processes during a computer-supported collaborative learning task and their relationship to group performance. Analogous to self-regulation during individual learning, we conceptualized social regulation both as individual and as collaborative activities of analyzing, planning, monitoring and evaluating cognitive and motivational aspects during collaborative learning. We analyzed the data of 42 participants working together in dyads. They had 90 min to develop a common handout on a statistical topic while communicating only via chat and common editor. The log files of chat and editor were coded regarding activities of social regulation. Results show that participants in dyads with higher group performance (N = 20) did not differ from participants with lower group performance (N = 22) in the frequencies of regulatory activities. In an exploratory way, we used process mining to identify process patterns for high versus low group performance dyads. The resulting models show clear parallels between high and low achieving dyads in a double loop of working on the task, monitoring, and coordinating. Moreover, there are no major differences in the process of high versus low achieving dyads. Both results are discussed with regard to theoretical and empirical issues. Furthermore, the method of process mining is discussed.     

College student cyberbullying on social networking sites: Conceptualization,prevalence, and perceived bystander responsibility

The majority of research on cyberbullying has been conducted with middle school and high school students and has not focused on specific technology platforms. The current study investigated college student experiences with cyberbullying on Social Networking Sites (SNS). College students (N = 196) from a northwestern university shared their conceptualizations of what cyberbullying looked like on SNS. Some college students (19%) reported that they had been bullied on SNS and 46% indicating that they had witnessed cyberbullying on SNS. The majority (61%) of college students who witnessed cyberbullying on SNS did nothing to intervene. College students were also asked about their perceived responsibility when they witnessed cyberbullying on SNS. Two diverging themes emerged that indicated some college students believed their responsibility to intervene was circumstantial, while others believed there is a constant clear level of responsibility for college student cyberbullying bystanders on SNS.     

大采高伪斜综采面老顶分段初次来压分析与控制

针对大采高大倾角伪斜综采面初采期间老顶分段初次来压的矿压显现规律,结合工作面具体的地质生产条件及初采期间老顶破断特征,分析了大采高伪斜综采面老顶呈现分段初次来压的原因,并提出了相应的支架—围岩稳定性控制措施。     

矿业用采煤机设备维护要点分析

当今设备维护在企业中的地位和作用日益突出,已经成为企业降低运营成本,赢得竞争优势的重要手段。本文针对矿业用采煤机故障要点提出设备维护的方式及对策。     

Who wants to be “friend-rich”? Social compensatory friending on Facebook and the moderating role of public self-consciousness

The present research aims to provide insight into social compensatory friending on social network sites by investigating the effects of self-esteem and self-consciousness on number of friends in the context of Facebook use. It was hypothesized that Facebook users low in self-esteem, when compared with high-self-esteem individuals, would engage in friending more actively and thereby accumulate a large number of friends as a way to compensate for the deficiency in self-esteem. We also hypothesized that the relationship between self-esteem and number of Facebook friends would vary depending on the levels of public self-consciousness. Data were collected from a college student sample in the United States (N = 234) based on an online cross-sectional survey. The results supported the hypothesis on social compensatory friending, demonstrating a negative association between self-esteem and number of Facebook friends. Furthermore, the data yielded support for the hypothesized moderating role of public self-consciousness in social compensatory friending: the negative association between self-esteem and number of Facebook friends was significant only for Facebook users who are high in public self-consciousness but not for those who are low in public self-consciousness. Implications for understanding social network site users’ friending behavior in light of social compensation motives are discussed.