On Corporate Virtue

This paper considers the question of virtues appropriate to a corporate actor’s moral character. A model of corporate appetites is developed by analogy with animal appetites; and the pursuit of initially virtuous corporate tendencies to an extreme degree is shown to be morally perilous. The author thus refutes a previous argument which suggested that (1) corporate virtues, unlike human virtues, need not be located on an Aristotelian mean between opposite undesirable extremes because (2) corporations do not have appetites; and (3) corporate virtues must serve the end of sustainable profit. If these disanalogies between corporate and human virtue no longer hold, then the stage is set for us to formulate a more adequate model of good corporate character that would encompass other-regarding virtues.     

用时延编码实现远程水声通信

本文研究了一种基于时延编码的远程水声通信技术，该技术利用线性调频（LFM）信号矩形脉冲的时延值进行时延编码，在接收端采用时延估计技术进行时延解码。初步的海试结果表明，该技术可以实现80km距离、4.16bit/s数据率的信息可靠传输。     

Measuring Efficiency: A Comparison of Multilevel Modelling and Data Envelopment Analysis in the Context of Higher Education

Data envelopment analysis (DEA) and multilevel modelling (MLM) are applied to a data set of 54,564 graduates from UK universities in 1993 to assess whether the choice of technique affects the measurement of universities’ performance. A methodology developed by Thanassoulis and Portela (2002; Education Economics, 10(2), pp. 183–207) allows each individual's DEA efficiency score to be decomposed into two components: one attributable to the university at which the student studied and the other attributable to the individual student. From the former component, a measure of each institution's teaching efficiency is derived and compared to the university effects from various multilevel models. The comparisons are made within four broad subjects: pure science, applied science, social science and arts. The results show that the rankings of universities derived from the DEA efficiencies which measure the universities’ own performance (i.e., having excluded the efforts of the individuals) are not strongly correlated with the university rankings derived from the university effects of the multilevel models. The data were also used to perform a university‐level DEA. The university efficiency scores derived from these DEAs are largely unrelated to the scores from the individual‐level DEAs, confirming a result from a smaller data set (Johnes, 2006a; European Journal of Operational Research, forthcoming). However, the university‐level DEAs provide efficiency scores which are generally strongly related to the university effects of the multilevel models.     

THE STATISTICS OF LONG-HORIZON REGRESSIONS REVISITED1

This paper compares commonly used approaches for estimating the relation between long-horizon returns and a predetermined variable X₁, such as dividend yields. Specifically, we look at regression of (i) nonoverlapping multiperiod returns on X_t (ii) overlapping multiperiod returns on X_t, (iii) single-period returns on multiperiod X_t, and (iv) single-period returns on X_t and its implied long-horizon regression coefficient. We provide analytical formulae which quantify the efficiency of the estimators used in the various approaches. Using the formulae, as well as Monte Carlo simulations, we demonstrate that the relative efficiency of the estimators used in the various approaches differs remarkably, depending on the dynamic structure of the regressor. of special interest for financial economists, when the regressors are highly autocorrelated, we find that the regressions (ii) (iii), and (iv) provide only marginal efficiency gains above and beyond the nonoverlapping long-horizon regression.     

一种新的OFDM同步跟踪技术及其在VHF/UHF通信系统中的应用

本文主要研究了我国加工贸易领域信息化管理的系统组成和发展状况,通过深入分析加工贸易的业务流程、信息化管理特点、发展困惑等内容,提出了优化加工贸易信息化管理的相关举措。     

小仰角下移动卫星通信性能的改善及仿真

移动卫星通信系统为功率受限系统,相对地面移动通信而言,其链路余量较小,而且由于多径及遮蔽效应,当系统工作在小仰角时,其信号衰落可达到30dB,这对系统的设计提出了严峻的挑战。本文研究了信道编码和交织技术在移动卫星通信系统中的应用。通过仿真,得到了应用该技术对不同仰角特别是小仰角条件下系统性能的改善程度。同时,在研究信道相关的基础上,给出了交织相关参数的设计准则。     

关于汉语/英语AMR语音编码参数统计特性的研究

自适应多速率（AMR）算法是第三代移动通信系统中语音业务所采用的语音编码标准。为研究AMR算法应用于汉语语音和英语语音所产生的差异，本文针对ARM语音编码算法的特点，在处理分析了大量汉语语音数据的基础上，对算法中的线谱频率（LSF）、基音周期等关键编码参数进行了比较并给出相应结合。本文的研究有助于AMR算法针对汉语语音的性能优化。     

Hyperbolic Efficiency and Parametric Distance Functions: With Application to Spanish Savings Banks

Distance functions are gaining relevance as alternative representations of production technologies, with growing numbers of empirical applications being made in the productivity and efficiency field. Distance functions were initially defined on the input or output production possibility sets by Shephard (1953, 1970) and extended to a graph representation of the technology by Färe, Grosskopf and Lovell (1985) through their graph hyperbolic distance function. Since then, different techniques such as non parametric-DEA and parametric-SFA have been used to calculate these distance functions. However, in the latter case we know of no study in which the restriction to input or output orientation has been relaxed. What we propose is to overcome such restrictiveness on dimensionality by defining and estimating a parametric hyperbolic distance function which simultaneously allows for the maximum equiproportionate expansion of outputs and reduction of inputs. In particular, we introduce a translog hyperbolic specification that complies with the conventional properties that the hyperbolic distance function satisfies. Finally, to illustrate its applicability in efficiency analysis we implement it using a data set of Spanish savings banks.     

Computer-assisted hospitality information systems

Within the last decade a vast array of computerized management information systems have become available to the hospitality industry. Their impact has not so far been significant, but where they have been introduced efficiency has increased, employees have gained greater professionalism and job satisfaction and cost effectiveness has improved.