LZW压缩数据的不均一两分段误码保护编码

由T.A.Welch提出的LZW数据压缩方法已经被广泛地应用于文字压缩。然而，因为误码对压缩数据的危害很大，所以对压缩数据的纠错编码是十分重要且必不可少的。本文分析了误码对LZW压缩数据的影响，指出同样的误码对用于重建辞书的前一部分压缩数据的危害比对后面的其它数据的危害要严重得多，提出用一种不均一两分段误码保护编码方法，对用于重建辞书的前一部分压缩数据进行更好地保护。计算机模拟显示，该方法比传统的误码保护方法更有效。     

无线数传中频FSK Modem的研究

<正> 社会王义市场经济的确立,使我国改革开放步入新的发展阶段。作为国家经济支柱的国有大中型企业,正从传统的管理体制中解放出来,以崭新的姿态融入国内经济大潮,迎接国际挑战。但大中型     

自适应无线传输技术在高速下行数据分组接入中的应用

随着高速、多媒体数据业务需求的日益增长 ,未来无线移动通信系统越来越需要解决支持更高速数据传输技术及频带利用率的问题 ,自适应传输技术是提高频带利用率的有效手段。结合最新3GPP提出的高速下行数据分组接入HSDPA ,归纳、总结和分析了自适应无线传输技术在HSDPA的应用以及其优点和应用前景、未来的研究方向     

Technology gaps in European banking: Put the blame on inputs or outputs?

This paper investigates the production efficiency of 12 European banking systems over the period 1997–2004, taking into account possible technology heterogeneity. Using a non-parametric metafrontier framework, efficiency and metatechnology ratio measures are computed and decomposed into input- and output-invariant components. Empirical findings indicate the existence of significant and rather increasing technology heterogeneity within European banking. A typology of the national banking systems is also developed, based on the overall productive performance with respect to the European technological edge, the absorptive capacity and the role of knowledge spillover effects. Decomposition results draw attention to catching up policies focusing on input and/or output scale adjustments.     

Identifying changes and trends in Hong Kong outbound tourism

Despite the numerous research endeavors aimed at investigating tourists’ preferences and motivations, it remains very difficult for practitioners to utilize the results of traditional association rule mining methods in tourism management. This research presents a new approach that extends the capability of the association rules technique to contrast targeted association rules with the aim of capturing the changes and trends in outbound tourism. Using datasets collected from five large-scale domestic tourism surveys of Hong Kong residents on outbound pleasure travel, both positive and negative contrasts are identified, thus enabling practitioners and policymakers to make appropriate decisions and develop more appropriate tourism products.     

Efficiency of travel agencies: A case study of Alicante,Spain

This study analyses the relative efficiency of 22 travel agencies of similar characteristics based in Alicante (Spain). This analysis is carried out using the Data Envelopment Analysis (DEA) technique and smoothed bootstrap. Following the analysis, possible lines of action that the agencies can take in order to improve their efficiency in the future are provided. Finally, using the Mann Whitney U Test, the relationship, or lack thereof, between the levels of efficiency of these agencies and their ownership type, location and level of experience is examined.     

含有中间变量的农村信用社可持续经营效率评价

本文借助含有中间变量的两阶段DEA评价方法对陕西省涉农地区不同信用社的可持续经营效率进行了评价。得出了大部分涉农地区基层信用社存在存款严重不足、发放贷款效率比吸收存款效率高、非利息支出过多、非利息收入不足等结论。     

Testing population variance in case of one sample and the difference of variances in case of two samples: Example of wage and pension data sets in Serbia

Testing one population variance and the difference in variances of two populations based on the ordinary t-statistics combined with the bootstrap method are suggested in this article. Suggested techniques are combined with Hall's transformation approach. Application of presented methods in domain of real economic data set is described and analyzed. We compare the outputs of suggested methods and traditional methods for considered data set. The results show that these introduced methods have small advantages in comparisons with traditional methods especially for small samples.     

An alternative approach to the monitoring of technological diffusion via foreign direct investment: evidence from the Greek manufacturing sector

The existing studies of foreign direct investment and the corresponding technological diffusion process that they generate, focus either on specific parameters of the production process in isolation, or they combine certain parameters to construct indices that are not consistent across studies. The present analysis proposes an alternative approach that captures the entire production process and multinational firms are viewed as the platform that transfers more advanced technologies to the host countries. As multinational firms are able to utilise more efficiently the available production process, an efficiency gap ensues between the domestically owned firms of a country and the multinational firms that operate in it. We capture and provide a measure and a monitoring mechanism of the technological diffusion process via foreign direct investment through the evolution of the efficiency gap between the two groups of firms whilst controlling for other variables that might contribute to such a gap. We apply our approach to the manufacturing sector of the Greek economy that experiences a consistent presence of foreign direct investment inflows over the time period 2001–2007.