最佳1/2卷积码VITERBI译码算法的简化

本文给出了1/2卷积码篱笆图蝶形结构各支路间关系的三个定理,及最佳1/2卷积码的特征。根据这些特征并利用译码过程中共有的中间变量,使译码运算次数减少为原来的5/6,简化不影响译码性能,并适用于硬判决和软判决译码方式。     

基于R-S码的二维OCDMA系统研究

根据R-S码构造了一种二维码,并按johnson边界条件研究了1===lllca的二维R-S码的码容量,分析结果表明,构造的码渐近为最优码;在只考虑多用户干扰的理想条件下,分析了多波长R-S码的二维OCDMA系统的误码率性能,得到了不同素数p构造的二维R-S码的误码率和并发用户数的关系曲线,为二维OCDMA的进一步研究提供了理论依据。     

Codes of conduct in Hong Kong organisations

This paper first reviews the literature on the role of codes of conduct for organisations in Hong Kong in their attempts to manage increasingly complex ethical problems and issues. It shows that, although valuable foundations exist upon which to build, research and understanding of the subject is at it's embryonic stage. Social Psychology literature is examined to investigate what lessons those concerned with the study of ethics may learn and the work of Hofstede, as seminal in the area of work-related values, is emphasised in this context.Following Hofstede's proposals for strategies for operationalizing¹ constructs about human values, a content analysis² was conducted on a pilot sample of codes provided by Hong Kong organisations. The results show three clearly identified clusters of organisations with common formats. The first group, described as Foreign Legal, emphasises legal compliance, has criteria for invoking penalties and consists of foreign-owned, large multinational organisations. Companies in the second cluster have codes which, except in the case of a couple of larger organisations, mainly follow the Independent Commission Against Corruption's (ICAC) standard format. The third cluster, described as the Bank Network, also appear to largely conform to a format: the Hong Kong Banking Association's guidelines.Further analysis conducted here of the Hong Kong codes indicates the important role of emic teleological values³, such as trust and reputation, amongst indigenous organisations, rather than the amorality suggested by an earlier study (Dolecheck and Bethke, 1990). These results support the proposition that Hong Kong ethical perspectives are culture bound⁴, as there appear to be different emphases than revealed in an American study (Stevens, 1994), which identified an emphasis in the US codes upon introverted organisational issues and a failure to espouse deontological values⁵.The conclusion is that designing a research programme on business values in Hong Kong requires reference to studies of values in cross-cultural psychology generally and to Hofstede's work in particular. It also supports the need for indigenous research and models in this field which avoid the ethnocentrism inherent in much Western theory and research.     

Collective Action,Everyday Protest,and Lived Religion

The conflict in 2001 at the Kukdong (now Mexmode) maquila garment factory is one of the rare cases of success in the wider struggle for independent unionism in Mexico. The success of the struggle, which has attracted scholars interested in the campaigns against sweatshop labour conditions and on behalf of labour internationalism, has been attributed chiefly to the role played by transnational advocacy networks in mobilizing pressure on the global sportswear giant Nike, whose brand-name, collegiate apparel was being produced in the plant. In this paper we seek not to explain why the struggle was successful, but to examine the trajectory it took over a protracted period of about nine months. We draw on McAdam et al.'s reformulation of the analysis of contentious, transgressive politics to identify three mechanisms that were particularly salient in shaping the course taken by the conflict: scale shift, actor decomposition, and brokerage. Scale shift occurred as the workers quickly escalated the conflict by broadening their demands from the resolution of particular concrete grievances to a demand for freedom of association that made the existing corporatist union, the FROC-CROC, which had a signed a protection contract with the plant's management, the principal target of opposition and challenge. Actor decomposition occurred as the workers' strategy locally and transnationally sought to isolate the FROC-CROC by detaching it from other members of the corporate–state bloc (Kukdong management, Nike, and the local political authorities). Brokerage, finally, occurred as Nike in particular was used to mediate pressure from the workers' transnational supporters (principally labour rights NGOs and the anti-sweatshop movement) on Kukdong and the local political authorities to respect the workers' right to freedom of association, which resulted in the ouster of the FROC-CROC as the legally certified union at the factory and its replacement with an independent union (SITEMEX) formed by the workers themselves.     

瑞利衰落信道Turbo码的精确性能上限

研究了慢变频率非选择性瑞利衰落信道下Turbo码的性能。采用修正的欧几里德距离量度和信道状态信息进行最大似然译码的Turbo译码器，推导出完全交织瑞利衰落信道基于联合限和码字重量分布的性能上限，为瑞利衰落信道下Turbo码的设计提供一个有效的分析工具。     

数字时代电视传播业的发展趋势

随着科学技术的发展,数字革命对我国电视传播业及相关产业的影响越来越明显,数码影像技术将从不同方面促进电视传播业的巨大变革.全面实现数字化、网络化、多媒体化是电视传播业在世纪之交努力的方向,联系国内外科学技术尤其是卫星数字电视发展的最新动态,有利于预测21世纪电视传播业发展变化趋势.     

阅读的心理分析

阅读是人们必不可少的一项活动，是了解信息、掌握知识的重要手段之一。本通过对阅读心理研究历史的回顾和评价，运用心理学、语言学的理论对阅读的心理活动过程做以分析阐述，提出了阅读心理“五过程”，即阅读意图的确立、识码、解码、编码、后联想过程。旨在探讨阅读过程的全面、综合的性质和特点，从而使阅读更具实效性。     

New combinatorial structures with applications to efficient group testing with inhibitors

Group testing with inhibitors (GTI) is a variant of classical group testing where in addition to positive items and negative items, there is a third class of items called inhibitors. In this model the response to a test is YES if and only if the tested group of items contains at least one positive item and no inhibitor. This model of group testing has been introduced by Farach et al. (Proceedings of compression and complexity of sequences, pp 357–367, 1997) for applications in the field of molecular biology. In this paper we investigate the GTI problem both in the case when the exact number of positive items is given, and in the case when the number of positives is not given but we are provided with an upper bound on it. For the latter case, we present a lower bound on the number of tests required to determine the positive items in a completely nonadaptive fashion. Also under the same hypothesis, we derive an improved lower bound on the number of tests required by any algorithm (using any number of stages) for the GTI problem. As far as it concerns the case when the exact number of positives is known, we give an efficient trivial two-stage algorithm. Instrumental to our results are new combinatorial structures introduced in this paper. In particular we introduce generalized versions of the well known superimposed codes (Du, D.Z., Hwang, F.K. in Pooling designs and nonadaptive group testing, 2006; Dyachkov, A.G., Rykov, V.V. in Probl. Control Inf. Theory 12:7–13, 1983; Dyachkov, A.G., et al. in J. Comb. Theory Ser. A 99:195–218, 2002; Kautz, W.H., Singleton, R.R. in IEEE Trans. Inf. Theory 10:363–377, 1964) and selectors (Clementi, A.E.F, et al. in Proceedings of symposium on discrete algorithms, pp. 709–718, 2001; De Bonis, A., et al. in SIAM J Comput. 34(5):1253–1270, 2005; Indyk, P. in Proceedings of symposium on discrete algorithms, pp. 697–704, 2002) that we believe to be of independent interest.     

Overwhelming Casualties: Medical Ethics in a Time of Terror

Codes of ethics and ethics guidelines define standards of professional conduct, and ways to prioritize or balance ethical principles when these appear to be in conflict. In 1991 an international and interdisciplinary group of scholars met at the University of Toronto to discuss these problems in a Workshop on Ethical Considerations in Scholarship and Science. A document, “The Toronto Resolution”; (TTR), was developed, providing twelve principles for incorporation into scientific and scholarly codes, with the object of ensuring that professionals in science recognize the potential consequences of their work in the broader social context. To examine the extent to which existing codes are consonant with The Toronto Resolution's 12 principles, a content analysis was conducted on the codes of 21 Ontario‐based scientific and scholarly organizations. Criteria used in the content analysis were standardized and determined to be reliable. Only a weak correspondence was found between the contents of the codes of the scientific and scholarly organizations surveyed here and the principles set out in TTR. In particular, guidelines on specific social issues such as environmental effects or conflict resolution are scarcely mentioned at all. This study encourages consideration of The Toronto Resolution by the ethics committees of scientific and scholarly associations, as codes are revised or as new interpretations of principles in the codes evolve.     

编撰经济法典的历史回眸

编撰经济法典是指有关经济法部门的经济法律法规的汇合编纂和基本经济法的撰写创制。编撰经济法典缘起于经济法的萌芽,经济法萌芽首先表现为个别法学家经济法思想的产生,而经济法思想也对经济法律法规的制定起了一定的指导作用。随着东西方国家经济法律法规的大量出现,经济法成了一种新兴的世界历史性的法律现象。这引发了经济法典的编撰,促进着经济法的完善,满足着以社会化生产为基础和以资本要素为核心的市场经济的需要。我国在制定和实施经济法、保障社会主义市场经济更好运行上的实践比较深入,我国的经济法理论研究也走在世界前列,因而在编撰经济法典上也可以为天下先,这将对世界法制文明的发展做出更大的贡献。