连续图像数字半调处理及性能分析

本文阐述了连续图像数字半调处理的基本理论，包括有序抖动数字半调处理、误差扩散数字半调处理，并对2种处理进行了性能分析。     

Towards developing financial management strategies for land reform beneficiaries in the Bloem‐fontein/Thaba Nchu area of the Free State province of South Africa

This article is based on research that was carried out to design financial management strategies for emerging farmers, and examines the financing problems anticipated for the beneficiaries of land reform in the Free State province. Discussions focus on criteria for detecting impending financial problems, in particular liquidity problems, and are based on the analysis of data gathered from emerging farmers by means of interviews and a questionnaire.     

An Asymptotic Solution for Sealed Bid Common-Value Auctions with Bidders Having Asymmetric Information

We investigate a first-price common-value auction where bidders have asymmetric information about an item of unknown value. We compute the unique Nash equilibrium when the bidders are constrained to translation-invariant bid functions. Further, this profile of bid functions is also an asymptotic Nash equilibrium (without the constraint on the bidders' strategies) as the a priori distribution of the true value becomes increasingly diffuse. All bidders have positive expected profits at equilibrium. In the second-price analogue with two bidders there is a continuum of Nash equilibria in which both bidders have positive expected profits. Journal of Economic Literature Classification Number: C7.     

Simple Procedures for Testing Autoregressive Versus Moving Average Errors in Regression Models

This paper develops several simple separate (or non-nested) procedures for testing autoregressive versus moving average errors in regression models. These asymptotically valid tests are straightforward to calculate: after estimating both models by maximum likelihood methods, the procedure involves testing the significance of variables added to a linearized version of the null model, the added variables being the predictions, or the residuals from the specified alternative model, or the difference of the predictions of the two models. Some small sample evidence on the properties of the tests is presented, as is an empirical application on the Australian unexpected inflation rate series.
JEL Classification Numbers: C12, C22, C52, E31.     

Preference Structures, Property Rights, and Paired Comparisons

The method of paired comparisons was used to determine the structure of survey participants' value expressions for Australian native forests. The same participants were also surveyed using the contingent valuation method (CVM). Data from the paired comparisons were used to construct preference maps which enabled identification of participants whose value expressions were structurally incompatible with economic welfare theory – in particular, those participants who expressed their values according to lexicographic preferences. For some of these participants, CVM results did not provide appropriate measures of WTP. The surveys also demonstrated the importance of allowing participants' own views on property rights to dictate the valuation context offered.     

中国男人

一条岁末裁员的消息，把大家的视线又集中到了搜狐身上。但是，尽管要裁员20%，尽管股价已经成为最低的中国门户股，尽管你看了新浪的报道以后会认为搜狐明天就要倒闭，如果你在国贸的滑冰场见到张朝阳，仍然应该对他投以英雄般的敬意，因为他不仅为中国引进了“门户网站、风险     

Response to L. Scott Miller

L. Scott Miller confronts us with the inadequacy of the schooling establishment's response to the educational needs of the special and rapidly growing group of minority students. Restructuring is urged as the most effective approach for meeting the urgent needs of disadvantaged at-risk students. Two experienced and prominent economics educators comment on the challenge and policy proposals.     

Your Place in Space: Classroom Experiment on Spatial Location Theory

The authors detail an urban economics experiment that is easily run in the classroom. The experiment has a flexible design that allows the instructor to explore how congestion, zoning, public transportation, and taxation levels determine the bid–rent function. Heterogeneous agents in the experiment compete for land use using a simple auction mechanism. Using the data that is collected, a bid–rent function is derived, and the experimental treatment is altered over the course of three sessions to uncover core concepts in urban economics. Moreover, this provides a tangible experience that can be used to help undergraduates relate to urban issues such as the steep rent gradient found around many larger colleges and universities.     

Profitability, Ownership Structure and Technical Efficiency of Enterprises in the People's Republic of China: A Case of Manufacturing Industries in Shanghai

This paper studies the relationship between accounting profits and technical efficiency of manufacturing enterprises in Shanghai during the period 1989–1992 and examines which factors affect the profitability of manufacturing enterprises. We first estimate the average technical efficiency of four major manufacturing industries in Shanghai. Then, we test for the presence of ownership effects of technical efficiency on profits of those enterprises in these four industries.