一种基于帧中继的多路语音编码芯片的研究

本文在介绍AudioCodes公司的AC4804A-C芯片的基础上，着重于研究该芯片的应用，并给出了应用结果。     

Penalized Regression with Ordinal Predictors

Ordered categorial predictors are a common case in regression modelling. In contrast to the case of ordinal response variables, ordinal predictors have been largely neglected in the literature. In this paper, existing methods are reviewed and the use of penalized regression techniques is proposed. Based on dummy coding two types of penalization are explicitly developed; the first imposes a difference penalty, the second is a ridge type refitting procedure. Also a Bayesian motivation is provided. The concept is generalized to the case of non-normal outcomes within the framework of generalized linear models by applying penalized likelihood estimation. Simulation studies and real world data serve for illustration and to compare the approaches to methods often seen in practice, namely simple linear regression on the group labels and pure dummy coding. Especially the proposed difference penalty turns out to be highly competitive.     

规则RA码在混合信道上的高斯估计

将高斯估计方法运用到规则重复累积（RA）码在具有加性白色高斯噪声和删除干扰的混合信道上的性能分析中．导出了RA码在该信道上概率密度进化的递归等式和误码率的解析表达式。仿真结果验证了解析结果的正确性。因此解析结果可以直接用来预测RA码在混合信道上的性能。     

中国农村地区教育私人收益率低的制度归因

与国际标准模型相比,中国农村教育私人收益率仍然偏低。转轨阶段双重分割的社会结构扭曲了劳动力的价格、日益凋敝的农村和农业以及城市偏向的教育投资政策增加了农村私人教育成本,抑制了农村教育私人收益率的提高。由此导致的人力资本投资不足是农民在既定制度约束下理性选择的结果。     

基于锁相环CD4046的跳频频率合成器设计

首先介绍了跳频扩频通信的定义、原理以及突出优点,其次阐述了跳频系统重要性能指标的改进以及常用伪随机序列跳频码RS序列的编码方法,接下来对系统的核心部件频率合成器进行了研究.最后基于锁相环频率合成法设计系统模块图,对其中所用CD4046、CC14526、CC4013等重要芯片进行了详细分析,将焊接好的电路板通过仿真实验并给出了结果.     

Assessing the viability of university alumni as a repeat visitor market

Both student and repeat visitor markets have been recognised by tourism academics and destination marketing agencies, but the alumni repeat visitor market has been neglected. The paper examines alumni propensity to return as tourists to their university city using a sample of graduates from a university in the North West of England. The large majority returned to the destination as tourists within six months of graduation, although visitation declined sharply after the first return visit. A cluster analysis using both motivation and constraint dimensions identified six a posteriori segments. Three of these were found to have significant potential because of their strong emotional attachment to the destination rather than the university. The accessibility of segments for targeting, through the development of links between the DMO and the educational institution, also supports their commercial viability.     

基于编码组建的公路工程计量支付台帐模型

基于有效编码组建的公路工程计量支付台帐能较好的满足现代高速公路项目信息管理的需求。论文针对高速公路全过程管理及信息化辅助管理,研究出完整编码体系,构建了计量支付台帐模型。     

对数相位板波前编码景深延拓系统研究

波前编码技术结合光学成像和数字信号处理,可以使系统的光学传递函数或点扩散函数对离焦不敏感,因而可以延拓光学成像系统的景深。文章以系统的点扩散函数对离焦不敏感为条件导出可以实现景深延拓的对数光瞳函数,这为目前波前编码技术中常用的3次相位调制函数提供了对照对象,为波前编码景深延拓技术的研究开辟了另一条途径。     

Improving the IATA delay data coding system for enhanced data analytics

Aviation delays inconvenience travelers and result in financial losses for stakeholders. Without complex data pre-processing, delay data collected by the existing IATA delay coding system are inadequate to support advanced delay analytics, e.g. large-scale delay propagation tracing in an airline network. Consequently, we developed three new coding schemes aiming at improving the current IATA system. These schemes were tested with specific analysis tasks using simulated delay data and were benchmarked against the IATA system. It was found that a coding scheme with a well-designed reporting style can facilitate automated data analytics and data mining, and an improved grouping of delay codes can minimise potential confusion at the data entry and recording stages.     

Disentangling the tourism sector’s fragmentation: a hands-on coding/post-coding guide for interview and policy document analysis in tourism†

Qualitative tourism research is inevitably multidimensional. The fragmentation of the tourism sector across policy domains, scales, space and stakeholders leads to ‘blurry’ and aggregated datasets. Yet, tourism studies have a weak record in describing how results emanate from raw qualitative data. This paper presents a coding/post-coding scheme that proved robust in disentangling multidimensional tourism datasets in a middle-range research project that necessitated reflecting on the position of the researcher and the literature study during the data analysis. It describes the pragmatic decisions taken to organise the qualitative data from a research project on cross-border tourism and regional development processes. The paper also functions as a reflexive account of how this scheme came into existence. It contributes to the tools available to practically acknowledge the fragmentation of the tourism sector and the resulting multidimensional qualitative data, and calls for a more open accounting of the data analysis process and the underlying research values in tourism studies.