吸毒人群社会支持网研究对重庆市南岸区戒毒所的调查

本文通过对重庆市南岸区戒毒所的调查,采用社会支持网分析方法,发现吸毒人员的社会支持网规模很小,吸毒网络具有秘密性和牢固性。其相识关系提供毒品支持,朋友关系和亲戚关系提供情感和经济支持。吸毒人员的吸毒年限、有抢劫和偷盗行为对注射吸毒行为和共用针头注射吸毒行为有明显的影响等一系列特征。     

Product Introduction Strategies under Sequential Innovation for Durable Goods with Network Effects

When network effects are important and technology is rapidly improved, this study explores the relative optimality of five product introduction strategies of a durable goods manufacturer: (1) replacement, (2) skipping, (3) a delayed line, (4) shelving, and (5) line‐extension. Using a two‐period analytical model, we show how the type of compatibility—either full or backward compatibility—and the magnitude of the network effect influence the manufacturer's preference for the above strategies. Our analysis reveals that only the strategies (1)–(3) above can be optimal; and the optimal strategy varies with network strength. Further, the type of compatibility can dramatically change the profitability under each optimal strategy; for instance, while backward compatibility can increase the profitability of replacement under certain conditions, it always reduces the profitability of a delayed line. We also illustrate that if compatibility were a choice, although backward compatibility may be observed widely in practice, the parametric region for its optimality is relatively more restricted than that of full compatibility.     

虚拟课堂在体育课程教学中的应用

本研究利用“虚拟课堂”针对体育课程教学进行实践教学探索,试图整合体育虚拟教学课堂教学资源。为提高体育课堂教学手段和方法提供有益参考和借鉴。探讨体育课程中实现虚拟课堂的可行性及必要性;探索体育课程实现虚拟课堂理论基础、设计与构建原则。结论：在体育课程中进行“虚拟课堂”的方式教学具有提高学习兴趣、改善动作质量、预防运动损伤、提高学生心理健康和丰富教学手段等效果．具有实现的可行性和必要性。     

企业网络组织的生成:中小企业发展的新思路

中小企业的发展对一国经济的意义非常重大。近年来方兴未艾的企业网络理论为中小企业的发展指明了一个崭新的方向。本文运用合作分工的观点 ,阐述了企业网络组织形成的本质和特征 ,从理论和实践两个角度说明了企业网络在促进中小企业发展方面的重要作用 ,并从中国的实际出发 ,分析了中小企业参与和建立企业网络组织的主要障碍 ,提出了相应的政策建议     

试论网络会计的形成及其发展对策

由于网络技术的产生及其在会计领域中的广泛应用,网络会计应运而生,成为会计发展的新领域。网络会计在产生及逐渐发展的过程中,面临着一些问题,需要制定相应对策,使网络会计逐步完善。     

网络传播与审美文化新变初探

信息传播方式的演进必然影响和促成审美观念的变迁。方兴未艾的网络传播为人类创造了全新的信息交流方式、审美感知世界的方式。网络传播对当代审美文化建设的积极意义在于,它催生了新的人际关系和交往方式,孕育了新的价值观和审美精神,刷新和激活了自由与共享、自主与平权、互助与奉献、开放与兼容等现代审美意识,极大地拓展了审美文化的空间。     

工程图学网络学习系统的设计与分析

针对目前工程图学教学和学习过程中存在的问题,提出了一种基于Web的工程图学网络学习系统的设计方案,并介绍其开发思路、开发方法和技术路线。该设计方案由前台浏览练习访问模块和后台数据库管理应用模块组成。这种设计方案把应用环境和开发环境分离开来为应用程序的开发和实现提供了很大的方便,同时这种开发模式逐渐成为必需的发展趋势。     

The NEGOPY network analysis program

A method and its associated computer program for (specifically communication) network analysis are described. The program described here, NEGOPY, is relational, or linkage-based. The conceptual orientation, computational algorithm, operating characteristics, format and availability of NEGOPY are described. Finally, a partial bibliography of works describing other aspects of NEGOPY and research studies using NEGOPY is included.     

On Approximation Ratios of Minimum-Energy Multicast Routing in Wireless Networks

In the broadcasting of ad hoc wireless networks, energy conservation is a critical issue. Three heuristic algorithms were proposed in Wieselthier et al.(2001) for finding approximate minimum-energy broadcast routings: MST(minimum spanning tree), SPT(shortest-path tree), and BIP(broadcasting incremental power). Wan et al.(2001) characterized their performance in terms of approximation ratios. This paper points out some mistakes in the result of Wan et al.(2001), and proves that the upper bound of sum of squares of lengths of the edges in Euclidean MST in unit disk can be improved to 10.86, thus improves the approximation ratios of MST and BIP algorithm.Supported by Natural Science Foundation of China (60223004, 603210022)     

网络环境下油田公司开放式运营管理研究——以苏里格气田为例

在阐述了企业内部价值链、外部价值网络与资源配置的基础上,对我国苏里格气田开放式运营管理的形成机理与开发模式进行了重点分析,以此考察了开放式运营管理对于中国油气生产企业的适应性与相关性,丰富和发展了开放式创新理论,这对我国油气生产企业的创新活动具有重要的指导作用.