非结构化数据存储管理研究

非结构化数据通常指相对于关系数据而言没有固定的显式结构的数据,比如视频、音频、图像、文档等非结构化数据。根据权威数据咨询机构或研究机构的预测报告显示,近 5～10年的数据量将呈指数级增长,而其中的非结构化数据占到当前数字信息总量的70%～85%。面对如此庞大的数据量和信息量,如何有效管理非结构化数据、获得有价值的信息或知识显得迫在眉睫。(非结构化) 数据管理可以简单化为3个目标,即:实现数据的“存得下、管得了、用的上”。本文将主要围绕前两个基本目标介绍目前的非结构化数据存储管理的研究情况。同时介绍中国人民大学非结构数据管理(Unstructured DataManagement,UDM)研究小组基于“自由表”数据模型和BUD(Bank of Unstructured Data)参考体系模型在这一个问题上所作的初步研究与探索工作,以及在原型平台myBUD中的若干存储管理技术。     

The Impact of Computer Self-Efficacy and Technology Dependence on Computer-Related Technostress: A Social Cognitive Theory Perspective

Professionals and end users of computers often experience being constantly surrounded by modern technology. One side effect of modern technology is termed technostress, which refers to the “negative impact on attitudes, thoughts, behaviors, or body physiology that is caused either directly or indirectly by technology” (Well and Rosen, 1997). Based on social cognitive theory, this study developed a conceptual model in which computer-related technostress was studied as consequences of computer self-efficacy and technology dependence. Results show that (a) employees with higher level of computer self-efficacy have lower level of computer-related technostress, (b) employees with higher level of technology dependence have higher level of computer-related technostress, and (c) employees under different individual situations may perceive different levels of technostress. Contributions of this research and implications for theory and managerial practice are also discussed.     

Uncertain term structure model of interest rate

Term structure models describe the evolution of the yield curve through time, without considering the influence of risk, tax, etc. Recently, uncertain processes were initialized and applied to option pricing and currency model. Under the assumption of short interest rate following uncertain processes, this study investigates the term-structure equation. This equation is first derived for valuing zero-coupon bond. Finally, analytic solutions of the uncertain interest rate equation are given when the process of interest rate is assumed to be the uncertain counterparts of the Ho-Lee model and Vasicek model, respectively.     

论网站页面设计的一致性原则

随着网络技术与电子商务的发展,网站页面设计也越来越受重视,优秀的网页虽然各有特色,但都遵守最基本的原则即保证页面的一致性。通过从页面结构、色彩、导航栏以及页面标准元素功能四个角度分析应如何设计网站页面,既保证页面之间的一致性,又使得读者不会因页面风格过于一致而产生视觉疲劳,并在此基础上提出了一个基本的保证页面一致性的设计方法。     

A novel fault-tolerant execution model by using of mobile agents

The exponential expansion of the Internet and the widespread popularity of the World Wide Web give a challenge to experts on reliable and secure system design, e.g., e-economy applications. New paradigms are on demand and mobile agent technology is one of the features. In this paper, we propose a fault-tolerance execution model by using of mobile agents, for the purpose of consistent and correct performance with a required function under stated conditions for a specified period of time. Failures are classified into two classes based on their intrinsic different effects on mobile agents. For each kind of failure, a specified handling method is adopted. The introduction of exceptional handling method allows performance improvements during mobile agents’ execution. The behaviors of mobile agents are statistically analyzed through several key parameters, including the migration time from node to node, the life expectancy of mobile agents, and the population distribution of mobile agents, to evaluate the performance of our model. The analytical results give new theoretical insights to the fault-tolerant execution of mobile agents and show that our model outperforms the existing fault-tolerant models. Our model provides an effective way to improve the reliability of computer systems.     

对等网环境下信任管理语言及安全凭证链查找方法

从P2P网络开放性、分布性、动态性等特点出发,给出了P2P环境下基于信任值的信任管理语言,实现了信任关系的初始建立。针对安全凭证链的查找问题,结合P2P网络的特点,提出了使用结果安全凭证并结合基于最小安全凭证图的安全凭证链查找算法,提高了安全凭证链的查找效率。     

Factors influencing health care professionals’ adoption of mobile platform of medical and senior care in China

A mobile platform of medical and senior care (MPMSC) is a platform that can provide one-stop medical and senior care services through mobile devices. This study developed a research model based on the value-based adoption model to understand the factors influencing health care professionals’ adoption of MPMSC. Empirical analysis has shown that perceived value and legal concerns can predict health care professionals’ intention to adopt MPMSC and that outcome expectations, perceived mobility, perceived effort, and privacy concerns can predict perceived value. Research findings can enhance the understanding of the factors influencing the adoption of MPMSC by health care professionals.     

The effects of social media posts’ characteristics on customer engagement: Evidence from WeChat

Many companies are using social media as emerging marketing channels in hopes of encouraging engagement by customers. This study explored the effect of multiple social media post cues on customer engagement. By distinguishing WeChat posts’ characteristics into outer- and inner-layer features, the findings suggest that outer-layer features (title linguistic vividness and top position) have positive effects on reads, and inner-layer features (post vividness and containing user-generated content) encouraged more likes, shares, and comments. In addition, by assigning post contents into sales and non-sales-related categories, we found the former attracts more comments and the latter is more helpful in promoting likes and shares. Further, within sales-related posts, storytelling category will receive more likes, whereas functional category boosts the number of shares.     

Effect of linguistic disfluency on consumer satisfaction: Evidence from an online knowledge payment platform

The popularity of online knowledge payment platforms enables online users to disseminate paid knowledge via voice communication. However, such communication provided by users with little professional teaching skills commonly tends to contain linguistic disfluency, which is a potential determinant of consumer satisfaction of paid knowledge products. This study examines how linguistic disfluency inherent in paid knowledge products impacts consumer satisfaction and the moderating effects of two consumer knowledge aspects, namely expertise and familiarity. Based on processing fluency theory, we build a theoretical model to illuminate relationships between consumer satisfaction, linguistic disfluency, and consumer knowledge. Leveraging data from Zhihu Live, a leading online knowledge payment platform, we find that linguistic disfluency is negatively associated with consumer satisfaction; nevertheless, this negative association disappears or turns into a positive effect for consumers with high expertise and low familiarity. Our study offers implications for platforms to accomplish high consumer satisfaction and further improve user retention and revenue.     

RTDMiner: 基于数据挖掘的引用计数更新缺陷检测方法

在Linux内核等大型底层系统中广泛采用引用计数来管理共享资源.引用计数需要与引用资源的对象个数保持一致,否则可能导致不恰当引用计数更新缺陷,使得资源永远无法释放或者被提前释放.为检测不恰当引用计数更新缺陷,现有静态检测方法通常需要知道哪些函数增加引用计数,哪些函数减少引用计数.而手动获取这些关于引用计数的先验知识过于费时且可能有遗漏.基于挖掘的缺陷检测方法虽然可以减少对先验知识的依赖,但难以有效检测像不恰当引用计数更新缺陷这类路径敏感的缺陷.为此,提出一个将数据挖掘技术和静态分析技术深度融合的不恰当引用计数更新缺陷检测方法 RTDMiner.首先,根据引用计数的通用规律,利用数据挖掘技术从大规模代码中自动识别增加或减少引用计数的函数.然后,采用路径敏感的静态分析方法检测增加了引用计数但没有减少引用计数的缺陷路径.为了降低误报,在检测阶段再次利用数据挖掘技术来识别例外模式.在Linux内核上的实验结果表明,所提方法能够以将近90%的准确率自动识别增加或减少引用计数的函数.而且RTDMiner检测到的排行靠前的50个疑似缺陷中已经有24个被内核维护人员确认为真实缺陷.