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71.
本文主要阐述了斜纹编织卷积码的编码结构、迭代译码以及活性距离和交织器对其误码性能的影响等基本概念。通过系统仿真,在AWGN信道下发现斜纹编织卷积码的系统性能与系统传输帧长和编码器个数都有很大的联系,其误码性能十分接近香农限,且没有错误地板效应。  相似文献   
72.
在简单介绍两种常用交织器的基础上,给出了随机分组交织器的设计,并进行了计算机仿真。结果表明,此交织器设计简单,占用内存少,性能明显优于分组交织器,而仅次于随机交织器。  相似文献   
73.
在多进程的实时应用程序中,进程之间往往需要通过传递一些信息来达到资源共享的目的。介绍了一种基于信号机制在UNIX实时应用中的两个进程之间实现快速传递信息的方法,提高了实时性。  相似文献   
74.
Ethics on the Web: Applying Moral Decision-Making to the New Media   总被引:1,自引:1,他引:0  
This paper examines the advent of the Web as a critical media tool in the promotion and sale of goods to consumers and the ethical questions it raises that are issues of public policy. We examine four traditional ethical rationales that guide organizational decision-making – utilitarianism, distributive justice, moral rights of man and relativism, further characterized as "ends-based", "equity-based", "rules-based" and "comparison-based" rationales – and we apply them to four moral dilemmas attributed to the proliferation of dot.com companies as they relate to consumer welfare. We find that ethical rationale in the New Media is largely non-existent, and where it exists, it is primarily reactive and driven by utilitarian or relativistic reasoning. We attribute this condition to the newness of the industry and to its economic context, representing, as it does, many characteristics embodied in the concept of the "perfect market." We offer some remedies to improve ethical conduct by e-business.  相似文献   
75.
We study the effects of organizational code‐preserving and code‐violating changes on external evaluations by third parties—an essential but under‐studied strategic outcome. We define code‐preserving changes as a variation in the firm's product range that preserves the social code within which the firm positions its offering. By contrast, a code‐violating change corresponds to a variation in the product range that breaks with past codes and embraces another social code. Our analyses of French haute cuisine restaurants show that code‐preserving changes and code‐violating changes have positive effects on external evaluations. Both effects decline with prior evaluations received by the organization, but only the effect of code‐violating changes is reduced with age. Moreover, external evaluations improve when restaurants undertake more code‐preserving changes than their direct competitors but decline when they make more code‐violating changes than competitors. These results enable us to derive implications for research on strategic change, strategic groups, and strategic social positioning. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
76.
在分析《建筑给水排水及采暖工程施工质量验收规范》特点的基础上,对新规范中七个方面的内容进行了分析和研究,指出了其中的不足和应改进的方案。  相似文献   
77.
More and more organisations formulate a code of conduct in order to stimulate responsible behaviour among their members. Much time and energy is usually spent fixing the content of the code but many organisations get stuck in the challenge of implementing and maintaining the code. The code then turns into nothing else than the notorious "paper in the drawer", without achieving its aims. The challenge of implementation is to utilize the dynamics which have emerged from the formulation of the code. This will support a continuous process of reflection on the central values and standards contained in the code. This paper presents an assessment method, based on the EFQM model, which intends to support this implementation process.  相似文献   
78.
In this fundamental draft we shall introduce the concept of social propositional spaces as a general notion of social science and in particular language, logic and methodology. This should help us bridge an old gap between extension and cognition, or said in more specific words, between space as conceived in mathematics or physics and space as is brought in by social location, by the meaning of predicates, their explanation and logic. 1 We shall not rely on the idea of factor analysis where some “main components” are fit into the data. Because the notion of euclidean normalization and orthogonality, in this context, is a bit artificial. We first show how combinatorial manifolds of statements can be represented in finite vector spaces over the Galois field F2. This space which we denote as logic statement space can be spanned by generators of alternating codes. In this way the old concepts of truth tables and interaction attributes can be linked to informatics and in particular code theory and geometry. Extending the logic statement space onto a real vector space by mapping units of the finite rings onto units of the real rings we obtain logistic statement spaces. It turns out that vectors in logistic statement spaces represent cross-tables of logits connected with logistic regression analysis. As a completion of the theory we show that the logit is the first derivative of entropy with respect to probability.  相似文献   
79.
针对通信侦察领域M-ary扩频信号的盲同步问题,根据M-ary扩频信号的结构特点及扩频码集元素间的相关特性,提出了一种扩频码长度和失步时间联合估计方法。该方法能够同时估计出M-ary扩频信号的扩频码长度及失步时间,且不受扩频码集类型的限制。仿真实验表明,该算法能在较低的信噪比条件下对三种不同码集的扩频信号进行估计,且算法的性能随着所使用数据的增多而提高。  相似文献   
80.
贺薇 《中国广告》2012,(8):130-132
在媒介融合的时代背景下,手机广告作为一种新兴的广告形式日益引起人们广泛关注。相对于传统媒体广告,二维码广告具有受众卷入程度高、传播内容立体化、较强的伴随性和互动性等特点。本文从精确测定广告效果、精准定位消费者、拓宽广告营销渠道、改变广告传播方式等四方面探讨了二维码对广告业的影响,并预测随着互联网的发展、智能手机的普及、3G服务的渗透,手机直接访问互联网将越来越便利,二维码这一新型广告形式将大有作为。  相似文献   
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