Efficient multicast search under delay and bandwidth constraints

The issue of a multicast search for a group of users is discussed in this study. Given the condition that the search is over only after all the users in the group are found, this problem is called the Conference Call Search (CCS) problem. The goal is to design efficient CCS strategies under delay and bandwidth constraints. While the problem of tracking a single user has been addressed by many studies, to the best of our knowledge, this study is one of the first attempts to reduce the search cost for multiple users. Moreover, as oppose to the single user tracking, for which one can always reduce the expected search delay by increasing the expected search cost, for a multicast search the dependency between the delay and the search cost is more complicated, as demonstrated in this study. We identify the key factors affecting the search efficiency, and the dependency between them and the search delay. Our analysis shows that under tight bandwidth constraints, the CCS problem is NP-hard. We therefore propose a search method that is not optimal, but has a low computational complexity. In addition, the proposed strategy yields a low search delay as well as a low search cost. The performance of the proposed search strategy is superior to the implementation of an optimal single user search on a group of users. Amotz Bar-Noy received the B.Sc. degree in 1981 in Mathematics and Computer Science and the Ph.D. degree in 1987 in Computer Science, both from the Hebrew University, Israel. From October 1987 to September 1989 he was a post-doc fellow in Stanford University, California. From October 1989 to August 1996 he was a Research Staff Member with IBM T. J. Watson Research Center, New York. From February 1995 to September 2001 he was an associate Professor with the Electrical Engineering-Systems department of Tel Aviv University, Israel. From September 1999 to December 2001 he was with AT research labs in New Jersey. Since February 2002 he is a Professor with the Computer and Information Science Department of Brooklyn College - CUNY, Brooklyn New York. Zohar Naor received the Ph.D. degree in Computer Science from Tel Aviv University, Tel Aviv, Israel, in 2000. Since 2003 he is with the University of Haifa, Israel. His areas of interests include wireless networks, resource management of computer networks, mobility, search strategies, and multiple access protocols.     

记第二届环太平洋先进材料及工艺国际会议

介绍第二届环太平洋先进材料及工艺国际会议情况，重点报导韩国钢铁工业、早期凝固过程研究、喷射成形、非晶合金、纳米材料和第三代单晶铸造高温合金等内容。     

我国冶金分析定量检测仪器的发展趋势

为了了解我国分析仪器的发展,推动冶金分析领域定量检测技术的进步,文章以北京分析测试学术报告会暨展览会(BCEIA)在国内的展示成果为依托,选择电感耦合等离子体发射光谱(ICP-OES)、电感耦合等离子体质谱(ICP-MS)、X射线荧光光谱(XRF)、激光诱导击穿光谱(LIBS)等基础定量检测仪器为主要分析对象,归纳总结了这些仪器的发展过程、基本原理和主要结构。从分析检测人员的视角,讨论了该检测仪器的优势特点及应用效果;展望了定量分析检测技术的发展趋势;提出了以定量检测仪器为基础的新型高端科学仪器的发展前景。又以激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)、辉光放电质谱(GD-MS)、电子探针X射线显微分析仪(EPMA)等拓展联用检测仪器为例,介绍了设备的主要特点及应用,最终总结出LA-ICP-MS为固体样品中微量元素分析的常用技术,GD-MS技术是痕量元素分析的重要手段,EPMA技术因具有与其他仪器结合包容性高的优点,虽然在使用过程中存在一定的缺陷,但已成为通用的分析手段。而我国定量分析检测技术正朝着现场化、专用化及标准化的方向发展。     

Evaluation of thermal and evaporative resistances in cricket helmets using a sweating manikin

The main objective of this study is to establish an approach for measuring the dry and evaporative heat dissipation cricket helmets. A range of cricket helmets has been tested using a sweating manikin within a controlled climatic chamber. The thermal manikin experiments were conducted in two stages, namely the (i) dry test and (ii) wet test. The ambient air temperature for the dry tests was controlled to ∼23 °C, and the mean skin temperatures averaged ∼35 °C. The thermal insulation value measured for the manikin with helmet ensemble ranged from 1.0 to 1.2 clo. The results showed that among the five cricket helmets, the Masuri helmet offered slightly more thermal insulation while the Elite helmet offered the least. However, under the dry laboratory conditions and with minimal air movement (air velocity = 0.08 ± 0.01 ms⁻¹), small differences exist between the thermal resistance values for the tested helmets. The wet tests were conducted in an isothermal condition, with an ambient and skin mean temperatures averaged ∼35 °C, the evaporative resistance, R_et, varied between 36 and 60 m² Pa W⁻¹. These large variations in evaporative heat dissipation values are due to the presence of a thick layer of comfort lining in certain helmet designs. This finding suggests that the type and design of padding may influence the rate of evaporative heat dissipation from the head and face; hence the type of material and thickness of the padding is critical for the effectiveness of evaporative heat loss and comfort of the wearer. Issues for further investigations in field trials are discussed.     

小康社会进程中益阳地方舞龙运动现状调查及发展对策研究

舞龙运动是一项民族传统体育,是民间体育项目中具有中国文化传承意义的体育项目,它承载着中华民族悠久而灿烂的历史文化,是中华文化传播广泛的重要载体.目前舞龙运动已逐渐成为一种具有鲜明传统体育特色的文化,且慢慢趋向于竞技化.综合运用文献资料法,问卷调查法,数据统计法等研究方法,对在小康社会进程中益阳民间舞龙运动的现状进行较为细致的调查研究,主要是从益阳民间舞龙运动的发展现状和龙队运行情况2个方面入手,并对当地群众及龙队所给的意见整理分析,给益阳民间舞龙运动的未来发展做了一些探讨,并提出相应的对策.     

会展英语言语及其翻译特点分析

随着世界商贸活动发展的快速和高频率,英语的使用也显得更加重要,它具有着交流的作用和商贸洽谈等诸多功效。在会展业高速发展的现今时代,也是需要与时俱进的会展英语,保障会展各项事物的深入广泛开展。作为具有专业用途的商业英语,会展英语具备着结构严谨、格式标准以及用词准确等预提特征,也成为现在最受瞩目的应用英语。更好地掌握会展英语的语体特征和翻译模式能够显著提升相关工作者的工作效率和工作质量,也是会展业发展的内在需求。需要结合现时代会展英语发展的最前沿领域,结合国内语言使用的文化内涵进行分析,本文以此为研究切入点,分析会展英语词汇、句子和语篇的实际应用和完善,探讨会展英语的翻译技巧,为相关工作者日后工作提供新的思路。     

Fair referee assignments for professional football leagues

Assignment of referees to football games is an important problem faced in professional football leagues. Despite its importance, the problem has received limited academic attention. This paper presents a model and analysis of the problem for fair referee assignments, and develops a constructive heuristic and a local search procedure for its solution. Results from an extensive computational study show that the methods are effective in solving the problem in a second of computation time and yielding an excellent solution quality.     

Automatic composition of broadcast sports video

This study examines an automatic broadcast soccer video composition system. The research is important as the ability to automatically compose broadcast sports video will not only improve broadcast video generation efficiency, but also provides the possibility to customize sports video broadcasting. We present a novel approach to the two major issues required in the system’s implementation, specifically the camera view selection/switching module and the automatic replay generation module. In our implementation, we use multi-modal framework to perform video content analysis, event and event boundary detection from the raw unedited main/sub-camera captures. This framework explores the possible cues using mid-level representations to bridge the gap between low-level features and high-level semantics. The video content analysis results are utilized for camera view selection/switching in the generated video composition, and the event detection results and mid-level representations are used to generate replays which are automatically inserted into the broadcast soccer video. Our experimental results are promising and found to be comparable to those generated by broadcast professionals.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008