从零部件贸易看中日韩分工差异

本文以中国为研究对象,对中国在日韩市场上零部件生产和组装的比较优势的分布、结构和变迁情况进行了细致梳理。通过分析扩展的RCA指标,得出结论,针对日韩两国市场而言,中国在零部件生产上的比较优势总体上呈增强趋势;在组装业务上,中等技术零部件逐渐呈现萎缩态势,而高技术零部件组装的比较优势正在扩大。随着时间的推移,中国同日韩两国之间的生产共享加强,而生产和组装结构也在一定程度上呈现出升级态势。     

Risk Preferences,Production Risk and Firm Heterogeneity*

A new technique is proposed for deriving the risk preference function under production risk and expected utility of profit maximization. The derivation depends on neither a specific parametric form of the utility function nor any distribution of the error term representing production risk. The proposed risk preference function is flexible enough to test different types of risk behavior and symmetry of the output distribution. Furthermore, our production risk specification allows for inputs with positive and negative marginal risk. The econometric model accommodates production risk, risk preferences and firm heterogeneity simultaneously. Norwegian salmon farming data are used as an application.     

Seasonal labor constraints and intra-household dynamics in the female fields of southern Cameroon

African agricultural production is modeled as a sequential decision process, with men's labor first allotted to clearing, then women's labor allotted to harvesting. A switching regression is then used to measure the constraints due to clearing labor capacity and harvesting labor capacity. The import of men's clearing labor depends on the valuation of shadow wages. Output appears to be more frequently constrained by husband's clearing labor, and in this situation male labor appears under‐utilized. However, output is also significantly constrained by female harvest labor, although the findings imply that female labor is over‐utilized at this stage.     

PLM education in production design and engineering by e-Learning

These days more attention is being paid to Product Lifecycle Management (PLM) using a technique for managing total product planning, design, manufacturing, sales, and disposal. We researched business processes and education curriculum of the PLM system in manufacturing businesses. We designed the curriculum of PLM education and developed part of a lesson. Most importantly, e-Learning is shown to be an effective tool for achieving educational objectives. We found that not only knowledge and theory but also practical education methods using case studies in an e-Learning environment are necessary for human resources to develop effective PLM.     

基于DEA模型的城市集约经营效率分析——以我国的15个副省级城市为例

DEA方法是进行相对有效性评价的一种方法，本文利用DEA模型的两种形式对我国15个副省级城市的集约经营效率进行了比较分析，并探讨了制约我国集约经济发展的重要因素及其对策。     

Understanding evolutionary processes in non-manufacturing industries: Empirical insights from the shakeout in pharmaceutical wholesaling

Although the empirical pattern of industry shakeout has been documented for many manufacturing industries, we know little about the processes by which market structure evolves in non-manufacturing service industries. This paper establishes detailed empirical observations about the consolidation of a single non-manufacturing industry, the wholesale distribution of pharmaceuticals. These observations are used to explore differences between manufacturing and wholesaling in both the patterns and explanations for consolidation and analyze the explanatory power of theories that link consolidation to technological change. The analysis demonstrates that theories developed to explain consolidation in new manufacturing industries have varying degrees of applicability to the consolidation of drug wholesaling. The observed patterns of exit, innovation, and growth suggest important modifications to evolutionary theories of market structure.     

西洋南瓜UGU生产的成本效益分析

本文通过成本效益分析方法对尼日利亚拉各斯市的西洋南瓜UGU生产利润及其影响因素进行了分析。文中通过“滚雪球”式抽样方式选取了60个南瓜瓜农，多数接受调查的瓜农在31～45岁之间，男女性分别为56．7％和43．3％，他们多数（68．3％）没有接受过正规教育。60％的接受调查者其生产成本较低，其成本每月不到1500奈拉。多数接受访问者其收入高于成本。南瓜生产在促进农民脱贫中起到了重要作用。研究表明教育水平、与推广机构的联系以及耕作经验对南瓜生产具有积极作用。因此，应促进瓜农与推广机构的联系以提高瓜农的收入，同时对于那些没有种植经验的瓜农也要给予帮助。     

Order release planning with clearing functions: A queueing-theoretical analysis of the clearing function concept

We consider the problem of planning future order releases in hierarchical production planning and control systems. An established research direction is the clearing function concept: the planned material flow through a production unit is modelled by inventory balance equations for WIP and final products, and the consequences of the stochastic properties of the material flow are modelled by clearing functions, which is the functional relationship between the level of WIP and the maximum output of a work centre in a period.Using a transient M/M/1 model, our paper shows that the usual definition of a nonlinear clearing function suffers from substantial shortcomings concerning both the definition of the function and empirical estimation of its parameters. We propose an alternative transient clearing function and derive a procedure for its parameterization.     

A production/remanufacture model with returns’ subassemblies managed differently

This paper considers a production-remanufacturing inventory model for a single product, where constant demand is satisfied from the inventory of newly produced and remanufactured items. Although the available models in the literature imply that collected used units (or returns) are disassembled for recovery purposes, these models really do not treat them as such. Contrary, the returns are assumed to be recovered as whole units, perhaps, for simplicity. This assumption may not capture the benefits reaped from product recovery programs. This paper addresses this limitation in the literature and assumes that each unit of a used product is collected and disassembled into components, where these components are sorted into subassemblies, which are fed back into the production-remanufacturing process. The returned subassemblies are remanufactured and reassembled to represent a second source of as-good-as-new units of the end-product. For this multi-component inventory problem, the question that needs to be answered is whether, or not, extreme strategies of either pure remanufacturing or pure production are more economical than a mixed strategy (one that combines both strategies). A mathematical model is developed that accounts for the inventories of subassemblies. The results suggested that not accounting for the disassembled components of a product leads to inappropriate inventory decisions that are not environmentally sound.     

Integrated production planning with sequence-dependent family setup times

This paper proposes an integrated optimization model of aggregate production planning (APP), family disaggregation planning, and family scheduling problems in hierarchical production planning (HPP) systems considering sequence-dependent family setup times. The model obtains the optimal production plan for each product type and product family in each period, together with the globally optimal production sequence of product families in all planning periods. The proposed model is tested with randomly generated experimental data consistent with what is prevalent in the manufacturing industry and its results are compared with those of the traditional HPP models. Our results show that the integrated model realizes greater cost savings.