With the popularity of wireless networks and the prevalence of personal mobile computing devices, understanding the characteristic of wireless network users is of great significance to the network performance. In this...With the popularity of wireless networks and the prevalence of personal mobile computing devices, understanding the characteristic of wireless network users is of great significance to the network performance. In this study, system logs from two universities, Dartmouth College and Shanghai Jiao Tong University(SJTU), were mined and analyzed. Every user's log was represented by a user profile. A novel weighted social similarity was proposed to quantify the resemblance of users considering influence of location visits. Based on the similarity, an unsupervised learning method was applied to cluster users. Though environment parameters are different, two universities both form many social groups with Pareto distribution of similarity and exponential distribution of group sizes. These findings are very important to the research of wireless network and social network .展开更多
Various networks exist in the world today including biological, social, information, and communication networks with the Internet as the largest network of all. One salient structural feature of these networks is the ...Various networks exist in the world today including biological, social, information, and communication networks with the Internet as the largest network of all. One salient structural feature of these networks is the formation of groups or communities of vertices that tend to be more connected to each other within the same group than to those outside. Therefore, the detection of these communities is a topic of great interest and importance in many applications and different algorithms including label propagation have been developed for such purpose. Speaker-listener label propagation algorithm (SLPA) enjoys almost linear time complexity, so desirable in dealing with large networks. As an extension of SLPA, this study presented a novel weighted label propagation algorithm (WLPA), which was tested on four real world social networks with known community structures including the famous Zachary's karate club network. Wilcoxon tests on the communities found in the karate club network by WLPA demonstrated an improved statistical significance over SLPA. Withthehelp of Wilcoxon tests again, we were able to determine the best possible formation of two communities in this network relative to the ground truth partition, which could be used as a new benchmark for assessing community detection algorithms. Finally WLPA predicted better communities than SLPA in two of the three additional real social networks, when compared to the ground truth.展开更多
Finding the shortest path (SP) in a large-scale network analysis between any two nodes is a tough but very significant task. The SP can help us to analyze the information spreading performance and research the laten...Finding the shortest path (SP) in a large-scale network analysis between any two nodes is a tough but very significant task. The SP can help us to analyze the information spreading performance and research the latent relationship in the weighted social network, and so on. As the size of the social network increases, the traditional SP algorithms have poor performance and there is not a suitable algorithm for weighted social network. Some features of the network analysis are beneficial to solve this problem, and community structure ignored by the traditional methods is one of the most important features. In this paper, we propose a shortest path algorithm based on community detection (SPCD) by integrating community detection algorithm with traditional search methods. SPCD constructs a community graph by using community structure to narrow the searching scope. The algorithm presented improves the time efficiency and maintains the accuracy scale of the SR Experimental results on five real-world networks demonstrate the effectiveness of the proposed methods for the SP problem.展开更多
Twitter is a tool for strengthening research knowledge mobilization to the general public. In this article, we highlight how Twitter can be used to open social dialogue about research related topics between users from...Twitter is a tool for strengthening research knowledge mobilization to the general public. In this article, we highlight how Twitter can be used to open social dialogue about research related topics between users from multiple perspectives, using the topic of weight bias;a cultural issue largely perpetuated by the media. Specifically, Twitter (@UCalgary Body BS) was used by an interdisciplinary research team to under line cases of global news, stories, and policy related to weight bias and/or weight-related issues for a broad audience to consume. We position Twitter as a relevant means for 1) shaping the research lifecycle, 2) increasing community participation and engagement regarding specific research topics, 3) co-creating evolving social dialogues and critique, 4) reaching broader audiences, 5) opening up sites of debate and tension within a topic, and 6) engaging with a topic salient within our society, a topic that saturates the media—weight bias.展开更多
Challenges inherent with the transition to college are often accompanied by weight gain among college freshmen. Weight gain and duration of obesity increase metabolic syndrome and cardiovascular disease risk in young ...Challenges inherent with the transition to college are often accompanied by weight gain among college freshmen. Weight gain and duration of obesity increase metabolic syndrome and cardiovascular disease risk in young adulthood, which supports the need for weight loss interventions tailored to college students. The purpose of this investigation was to conduct a mixed methods pilot trial to determine the efficacy and acceptability of a semester long Internet-and incentive-based weight loss intervention for overweight/obese college freshmen. Participants (n = 27, aged >18 yrs, BMI >25) were randomly assigned to a 12-week social cognitive theory (SCT)-based intervention (Fit Freshmen [FF]) or a health information control group. The FF intervention also included modest financial incentives for weight loss. Primary outcomes included body weight/composition, dietary and physical activity (PA) behaviors, and psychosocial measures (i.e. self-efficacy, self-regulation) associated with diet, PA, and weight loss. Students in the FF intervention participated in focus groups to provide qualitative feedback on program structure and design. FF participants demonstrated significant reductions (all group differences展开更多
The introduction of the social networking platform has drastically affected the way individuals interact. Even though most of the effects have been positive, there exist some serious threats associated with the intera...The introduction of the social networking platform has drastically affected the way individuals interact. Even though most of the effects have been positive, there exist some serious threats associated with the interactions on a social networking website. A considerable proportion of the crimes that occur are initiated through a social networking platform [1]. Almost 33% of the crimes on the internet are initiated through a social networking website [1]. Moreover activities like spam messages create unnecessary traffic and might affect the user base of a social networking platform. As a result preventing interactions with malicious intent and spam activities becomes crucial. This work attempts to detect the same in a social networking platform by considering a social network as a weighted graph wherein each node, which represents an individual in the social network, stores activities of other nodes with respect to itself in an optimized format which is referred to as localized data set. The weights associated with the edges in the graph represent the trust relationship between profiles. The weights of the edges along with the localized data set are used to infer whether nodes in the social network are compromised and are performing spam or malicious activities.展开更多
为了评价多因素耦合作用下高海拔地区铁路工程施工人员作业疲劳状况。首先,建立作业疲劳影响因素指标体系,并根据涌现理论,从工作本身、作业人员、作业环境和组织管理4个维度将耦合作用分为单因素耦合、双因素耦合和多因素耦合;其次,以...为了评价多因素耦合作用下高海拔地区铁路工程施工人员作业疲劳状况。首先,建立作业疲劳影响因素指标体系,并根据涌现理论,从工作本身、作业人员、作业环境和组织管理4个维度将耦合作用分为单因素耦合、双因素耦合和多因素耦合;其次,以高海拔地区铁路工程施工项目为例,利用熵权-决策实验室分析(Entropy Weight Method-Decision Making Trial and Evaluation Laboratory, EWM-DEMATEL)法确定指标权重,构建耦合度模型,进而对作业疲劳影响因素间的耦合关系进行定量分析,寻找关键耦合因素;最后,建立施工人员作业疲劳“工-管”耦合系统的系统动力学模型,并动态观测疲劳影响因素对施工人员疲劳水平发展趋势的影响。结果显示,工作本身和组织管理的耦合度最大,且疲劳水平的增长速率在第5周后明显增加。在施工作业过程中,应提前建立有针对性的管理措施来降低疲劳影响因素之间的耦合效应。展开更多
为保障地铁项目的可持续发展,从有形和无形效益2方面研究民生视角下地铁项目的社会效益。结合文献分析及专家社会调查,构建地铁项目社会效益评价指标体系;采用熵权-决策试验和评价试验(decision-making trial and evaluation laboratory...为保障地铁项目的可持续发展,从有形和无形效益2方面研究民生视角下地铁项目的社会效益。结合文献分析及专家社会调查,构建地铁项目社会效益评价指标体系;采用熵权-决策试验和评价试验(decision-making trial and evaluation laboratory,DEMATEL)法分别确定各指标的客观权重和主观权重,并将熵权法和DEMATEL法相结合确定组合权重;以青岛地铁13号线为例,采用模糊综合评价法评价其社会效益,验证评价方法的可行性。研究表明:90.43%的受访者对地铁带来的社会效益呈满意态度,地铁开通对节能降碳等有形效益具有显著作用,对宜居、宜业、宜游等无形效益具有贡献作用。展开更多
在线社交网络中虚假信息传播蔓延成为当前网络空间安全治理面临的重要挑战。提出一种融合用户传播风险和节点影响力分析的虚假信息传播控制方法DDC-UPRNI(disinformation diffusion control method integrating user propagation risk a...在线社交网络中虚假信息传播蔓延成为当前网络空间安全治理面临的重要挑战。提出一种融合用户传播风险和节点影响力分析的虚假信息传播控制方法DDC-UPRNI(disinformation diffusion control method integrating user propagation risk and node influence analysis)。综合考虑虚假信息传播特征空间的多样性和复杂性,通过自注意力机制实现用户传播虚假信息行为维度、时间维度和内容维度特征的嵌入表示,运用改进的无监督聚类K-means++算法实现不同用户传播风险等级的自动划分;设计一种自适应加权策略实现对离散粒子群优化算法的改进,进而提出一种基于离散粒子群优化的虚假信息传播关键节点选取方法,用于从具有特定传播风险等级的用户节点集合中选取若干个具有影响力的控制驱动节点,从而实现精准、高效的虚假信息传播控制;基于现实在线社交网络平台上开展试验,结果表明,所提出的DDC-UPRNI方法与现有算法相比,在控制效果和时间复杂度等重要指标上具有明显优势。该方法为社会网络空间中的虚假信息管控治理提供重要参考。展开更多
基金National Natural Science Foundation of China(No. 60970106)National High Technology Research and Development Program of China( No. 2011AA010500)
文摘With the popularity of wireless networks and the prevalence of personal mobile computing devices, understanding the characteristic of wireless network users is of great significance to the network performance. In this study, system logs from two universities, Dartmouth College and Shanghai Jiao Tong University(SJTU), were mined and analyzed. Every user's log was represented by a user profile. A novel weighted social similarity was proposed to quantify the resemblance of users considering influence of location visits. Based on the similarity, an unsupervised learning method was applied to cluster users. Though environment parameters are different, two universities both form many social groups with Pareto distribution of similarity and exponential distribution of group sizes. These findings are very important to the research of wireless network and social network .
文摘Various networks exist in the world today including biological, social, information, and communication networks with the Internet as the largest network of all. One salient structural feature of these networks is the formation of groups or communities of vertices that tend to be more connected to each other within the same group than to those outside. Therefore, the detection of these communities is a topic of great interest and importance in many applications and different algorithms including label propagation have been developed for such purpose. Speaker-listener label propagation algorithm (SLPA) enjoys almost linear time complexity, so desirable in dealing with large networks. As an extension of SLPA, this study presented a novel weighted label propagation algorithm (WLPA), which was tested on four real world social networks with known community structures including the famous Zachary's karate club network. Wilcoxon tests on the communities found in the karate club network by WLPA demonstrated an improved statistical significance over SLPA. Withthehelp of Wilcoxon tests again, we were able to determine the best possible formation of two communities in this network relative to the ground truth partition, which could be used as a new benchmark for assessing community detection algorithms. Finally WLPA predicted better communities than SLPA in two of the three additional real social networks, when compared to the ground truth.
文摘Finding the shortest path (SP) in a large-scale network analysis between any two nodes is a tough but very significant task. The SP can help us to analyze the information spreading performance and research the latent relationship in the weighted social network, and so on. As the size of the social network increases, the traditional SP algorithms have poor performance and there is not a suitable algorithm for weighted social network. Some features of the network analysis are beneficial to solve this problem, and community structure ignored by the traditional methods is one of the most important features. In this paper, we propose a shortest path algorithm based on community detection (SPCD) by integrating community detection algorithm with traditional search methods. SPCD constructs a community graph by using community structure to narrow the searching scope. The algorithm presented improves the time efficiency and maintains the accuracy scale of the SR Experimental results on five real-world networks demonstrate the effectiveness of the proposed methods for the SP problem.
文摘Twitter is a tool for strengthening research knowledge mobilization to the general public. In this article, we highlight how Twitter can be used to open social dialogue about research related topics between users from multiple perspectives, using the topic of weight bias;a cultural issue largely perpetuated by the media. Specifically, Twitter (@UCalgary Body BS) was used by an interdisciplinary research team to under line cases of global news, stories, and policy related to weight bias and/or weight-related issues for a broad audience to consume. We position Twitter as a relevant means for 1) shaping the research lifecycle, 2) increasing community participation and engagement regarding specific research topics, 3) co-creating evolving social dialogues and critique, 4) reaching broader audiences, 5) opening up sites of debate and tension within a topic, and 6) engaging with a topic salient within our society, a topic that saturates the media—weight bias.
文摘Challenges inherent with the transition to college are often accompanied by weight gain among college freshmen. Weight gain and duration of obesity increase metabolic syndrome and cardiovascular disease risk in young adulthood, which supports the need for weight loss interventions tailored to college students. The purpose of this investigation was to conduct a mixed methods pilot trial to determine the efficacy and acceptability of a semester long Internet-and incentive-based weight loss intervention for overweight/obese college freshmen. Participants (n = 27, aged >18 yrs, BMI >25) were randomly assigned to a 12-week social cognitive theory (SCT)-based intervention (Fit Freshmen [FF]) or a health information control group. The FF intervention also included modest financial incentives for weight loss. Primary outcomes included body weight/composition, dietary and physical activity (PA) behaviors, and psychosocial measures (i.e. self-efficacy, self-regulation) associated with diet, PA, and weight loss. Students in the FF intervention participated in focus groups to provide qualitative feedback on program structure and design. FF participants demonstrated significant reductions (all group differences
文摘The introduction of the social networking platform has drastically affected the way individuals interact. Even though most of the effects have been positive, there exist some serious threats associated with the interactions on a social networking website. A considerable proportion of the crimes that occur are initiated through a social networking platform [1]. Almost 33% of the crimes on the internet are initiated through a social networking website [1]. Moreover activities like spam messages create unnecessary traffic and might affect the user base of a social networking platform. As a result preventing interactions with malicious intent and spam activities becomes crucial. This work attempts to detect the same in a social networking platform by considering a social network as a weighted graph wherein each node, which represents an individual in the social network, stores activities of other nodes with respect to itself in an optimized format which is referred to as localized data set. The weights associated with the edges in the graph represent the trust relationship between profiles. The weights of the edges along with the localized data set are used to infer whether nodes in the social network are compromised and are performing spam or malicious activities.
文摘为了评价多因素耦合作用下高海拔地区铁路工程施工人员作业疲劳状况。首先,建立作业疲劳影响因素指标体系,并根据涌现理论,从工作本身、作业人员、作业环境和组织管理4个维度将耦合作用分为单因素耦合、双因素耦合和多因素耦合;其次,以高海拔地区铁路工程施工项目为例,利用熵权-决策实验室分析(Entropy Weight Method-Decision Making Trial and Evaluation Laboratory, EWM-DEMATEL)法确定指标权重,构建耦合度模型,进而对作业疲劳影响因素间的耦合关系进行定量分析,寻找关键耦合因素;最后,建立施工人员作业疲劳“工-管”耦合系统的系统动力学模型,并动态观测疲劳影响因素对施工人员疲劳水平发展趋势的影响。结果显示,工作本身和组织管理的耦合度最大,且疲劳水平的增长速率在第5周后明显增加。在施工作业过程中,应提前建立有针对性的管理措施来降低疲劳影响因素之间的耦合效应。
文摘为保障地铁项目的可持续发展,从有形和无形效益2方面研究民生视角下地铁项目的社会效益。结合文献分析及专家社会调查,构建地铁项目社会效益评价指标体系;采用熵权-决策试验和评价试验(decision-making trial and evaluation laboratory,DEMATEL)法分别确定各指标的客观权重和主观权重,并将熵权法和DEMATEL法相结合确定组合权重;以青岛地铁13号线为例,采用模糊综合评价法评价其社会效益,验证评价方法的可行性。研究表明:90.43%的受访者对地铁带来的社会效益呈满意态度,地铁开通对节能降碳等有形效益具有显著作用,对宜居、宜业、宜游等无形效益具有贡献作用。
文摘在线社交网络中虚假信息传播蔓延成为当前网络空间安全治理面临的重要挑战。提出一种融合用户传播风险和节点影响力分析的虚假信息传播控制方法DDC-UPRNI(disinformation diffusion control method integrating user propagation risk and node influence analysis)。综合考虑虚假信息传播特征空间的多样性和复杂性,通过自注意力机制实现用户传播虚假信息行为维度、时间维度和内容维度特征的嵌入表示,运用改进的无监督聚类K-means++算法实现不同用户传播风险等级的自动划分;设计一种自适应加权策略实现对离散粒子群优化算法的改进,进而提出一种基于离散粒子群优化的虚假信息传播关键节点选取方法,用于从具有特定传播风险等级的用户节点集合中选取若干个具有影响力的控制驱动节点,从而实现精准、高效的虚假信息传播控制;基于现实在线社交网络平台上开展试验,结果表明,所提出的DDC-UPRNI方法与现有算法相比,在控制效果和时间复杂度等重要指标上具有明显优势。该方法为社会网络空间中的虚假信息管控治理提供重要参考。