我们是怎样筹办国际研讨会的

中国科技新闻学会是一个成立较晚,只有两名固定编制,基本会员千人的交叉学科小型学会。但自从1988年成立以来,它已成功举办了四届大型国际会议——“亚太地区媒体与科技和社会发展研讨会”。一、研讨会概况“亚太地区媒体与科技和社会发展研讨会”是由中国科协下属的中国国际科     

我们如何谈论技术的本质

文章就流行的技术本质、定义观念进行了元理论分析 ;描述了工具论的、实体论的及批判的技术理论。着重考察了A·芬伯格的非本质主义初级、次级工具化理论 ,以及相关反本质主义、后本质主义技术本质观。指出了维特根斯坦“家族相似”之于谈论技术本质与定义的重要意义 ,以及将技术视作“本文”并对其进行解释学研究的可能性。     

我们应该如何应对气候变化

气候安全已不仅是一个科学命题,而应站在国家利益的高度,站在全球化的高度对待。2004年,美国国防部曾组织撰写一份关于气候突变情形下各国国情分析及相应对策的秘密报告,引起了广泛关注,这仅是泄漏出来的报告,未被泄漏的应该还有。这说明气候变化已成为一些政府发展其国家规划和全球战略的重要依据。然而,目前关于气候变化的预测还具有很大的不确定性。更重要的是,人类活动与气候环境是相互作用的。因而,当前及未来的气候变化不完全是个自然过程。本文就如何应对气候变化,说明其中产生的新的科研需求,提出若干建议和措施。     

我国政府和企业如何获得竞争优势

一个国家的比较优势产业和生产环节未必一定具有竞争优势。在提升我们的产业结构、实现比较优势的动态转移时，要培育我们的竞争优势。竞争优势是以企业为核心的。一批富有竞争力的企业群是国家综合竞争力的关键。政府的职责是为培育竞争优势提供基本的“操作系统”，企业是参与竞争的各种“应用软件”。企业获得竞争优势的关键在于创新。     

如何引导学生迈好英语学习的第一步

调查显示,许多学生英语学习不理想,根源出自于起步阶段,因而迈好英语学习第一步十分重要,文章从施教者的角度提出在学习英语的初始阶段,要从培养兴趣、掌握方法、启发思维、养好习惯、寓教于乐五个方面对学生作好引导。     

How are we searching the World Wide Web? A comparison of nine search engine transaction logs

The Web and especially major Web search engines are essential tools in the quest to locate online information for many people. This paper reports results from research that examines characteristics and changes in Web searching from nine studies of five Web search engines based in the US and Europe. We compare interactions occurring between users and Web search engines from the perspectives of session length, query length, query complexity, and content viewed among the Web search engines. The results of our research shows (1) users are viewing fewer result pages, (2) searchers on US-based Web search engines use more query operators than searchers on European-based search engines, (3) there are statistically significant differences in the use of Boolean operators and result pages viewed, and (4) one cannot necessary apply results from studies of one particular Web search engine to another Web search engine. The wide spread use of Web search engines, employment of simple queries, and decreased viewing of result pages may have resulted from algorithmic enhancements by Web search engine companies. We discuss the implications of the findings for the development of Web search engines and design of online content.     

放大科技计划正外部效应途径分析——芬兰科技计划组织机制对我国的启示

以政府资金为主的国家科技计划具有明显的公共产品的性质,政府组织实施科技计划不仅仅是为了促进某一领域或专题的科技水平,更重要的是通过科技计划的辐射作用,提升整个国家的科技实力、科技能力和科技效力,最终促进经济、社会的快速发展。通过对芬兰科技计划组织机制的分析,得出放大科技计划外部效应的4个途径,并提出若干关于科技计划组织管理的政策建议。     

Fault tolerant flight control system for the tilt-rotor UAV

A fault tolerant control scheme for actuator and sensor faults is proposed for a tilt-rotor unmanned aerial vehicle (UAV) system. The tilt-rotor UAV has a vertically take-off and landing (VTOL) capability like a helicopter during the take-off & landing while it could cruise with a high speed as a conventional airplane flight mode. A dual system in the flight control computer (FCC) and the sensor is proposed in this study. To achieve a high reliability, a fault tolerant flight control system is required for the case of actuator or sensor fault. For the actuator fault, the fault tolerant control scheme based on model error control synthesis is presented. A designed fault tolerant control scheme does not require system identification process and it provides an effective reconfigurability without fault detection and isolation (FDI) process. For the sensor fault, the fault tolerant federated Kalman filter is designed for the tilt-rotor UAV system. An FDI algorithm is applied to the federated Kalman filter in order to improve the accuracy of the state estimation even when the sensor fails. For a linearized six-degree-of-freedom linear model and nonlinear model of the tilt-rotor UAV, numerical simulation and process-in-the-loop simulation (PILS) are performed to demonstrate the performance of the proposed fault tolerant control scheme.