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.     

McSEIS-1600地震仪磁盘记录格式及数据解编系统

McSEIS-1600地震仪,把采集到的数据记录在一块双面双密度3.5英寸软磁盘上。磁盘记录格式为:每面80磁道,每盘160磁道,每磁道5扇区,每扇区1024字节,与IBM-PC系列计算机磁盘格式不兼容。记录按炮点目录中的索引地址顺序存放,采集数据按高位在前低位在后存放。这种格式的数据都可在IBM-PC系列计算机上通过用C语言编写的程序修改磁盘参数进行读取,从而对这些数据进行处理。     

Modelling multinational telecommunications demand with limited data

Forecasting the diffusion of innovations in the telecommunications sector is a constantly recurring problem for national providers. The problem is characterised by short data series making the estimation of model parameters unreliable. However, the same innovation will be diffusing simultaneously in other national markets, although with a different start date. The use of this cross-sectional data in constructing innovation diffusion models is investigated here. Four models for pooling the cross-sectional data are described and two diffusion models are discussed although only one, the Gompertz model is used throughout. Three innovation data sets are used in the evaluation of the models: digital cellular telephones, ISDN connections and fax connections. The pooled diffusion forecasts proved to be more accurate in several comparisons relative to a naïve benchmark and to individual forecasts when available.     

混叠通信信号的盲分离处理

同频混叠信号的处理一直是通信信号处理中的难点,常规的信号处理方法难以对其进行有效分析。本文运用最新的盲源分离理论,实现了混叠通信信号的盲分离。仿真结果表明,本文采用的算法分离效果好,运算速度快,可移植性强,基本实现了对混叠通信信号的实时盲分离。     

基于G4平台的嵌入式VxWorks系统在雷达信号处理中的应用

G4平台能快速处理板内节点间以及板间的大数据流通信,本文主要介绍通用G4硬件平台的基本结构特点和相关软硬件,分析基于抢占式多任务VxW orks实时操作系统的优点;充分利用VxW orks操作系统和G4硬件平台特点,完成了雷达数字信号处理中的管理与控制,成功实现了某雷达系统的实时数字信号处理。     

A TEST OF A GENERAL EQUILIBRIUM STOCK OPTION PRICING MODEL

An empirical version of the Cox, Ingersoll, and Ross (1985a) call option pricing model is derived, assuming execution price uncertainty in the options market. the pricing restrictions come in the form of moment conditions in the option pricing error. These can be estimated and tested using a version of the method of simulated moments (MSM). Simulation estimates, obtained by discretely approximating the risk-neutral processes of the underlying stock price and the interest rate, are substituted for analytically unknown call prices. the asymptotics and other aspects of the MSM estimator are discussed. the model is tested on transaction prices at 15-minute intervals. It substantially outperforms the Black-Scholes model. the empirical success of the Cox-Ingersoll-Ross model implies that the continuous-time interest rate implicit in synchronous transaction quotes of 90-day Treasury-bill futures contracts is an-albeit noisy-proxy for the instantaneous volatility on common stock. the process of the instantaneous volatility is found to be close to nonstationary. It is well approximated by a heteroskedastic unit-root process. With this approximation, the Cox-Ingersoll-Ross model only slightly overprices long-maturity options.     

如何看待玉米的生物能源地位

能源短缺困扰世界经济的发展,许多国家纷纷调整能源政策,寻找矿物质能源的替代产品.玉米作为集粮,经、饲为一体的经济作物,研发燃料乙醇作为能源替代品,得到了世界各国的普遍关注和重视.     

The intertemporal stability of the concentration-margins relationship in Dutch and U.S. manufacturing

Factors influencing price-cost margins are investigated using a rich panel data base of the Dutch manufacturing sector. Attention is devoted to the intertemporal stability of the relationship explaining price-cost margins and to a comparison with U.S. results. Our results indicate that isolated cross-section analyses can be misleading. Evidence is provided for similarities and dissimilarities between the U.S. and the Netherlands when explaining price-cost margins. Dutch margins are influenced by industry-specific factors such as sales changes, import competition, capital intensity and operating expenses. Domestic seller concentration, aggregate capacity utilization and export intensity play no distinct roles.This research was sponsored in part by the Economics Research Foundation, which is part of the Netherlands Organization for Scientific Research. We wish to thank H. W. de Jong, Leo Sleuwaegen, David Audretsch and Aad Kleijweg for their useful comments.