Liberalization policy, production and cost efficiency in Taiwan’s telecommunications industry

Many economists, policy-makers, and corporate managers have long believed that the operational performance of private enterprises is much more efficient than that of public utilities. However, some researches on changes in efficiency before and after privatization contradict this. The purpose of this paper is to analyze changes in technical and cost efficiency in Chunghwa Telecom Company (CHT) before and after partial privatization.The input-orientation Data Envelopment Analysis (DEA) and Cost-DEA were the research tools used in this study, and the findings showed that the technical efficiency, allocation efficiency, and cost efficiency become worse after partial privatization. Additionally, we found that CHT cannot achieve any significant improvement in cost management under its partial privatization environment. CHT is still restricted by government policies and regulations, thus undermining its ability to achieve any significant improvement in its cost management. In order to improve efficiency for CHT, the government needs to eliminate some regulations and relax its control over CHT, thus creating a completely privatized environment.     

Effect of material microstructure and tool geometry on surface generation in single point diamond turning

There is a strong desire in industry to improve surface finish when performing ultra-precision, single point diamond turning (SPDT) to reduce the amount of post process polishing required to meet final product specifications. However there are well known factors in SPDT which limit achievable surface finish. This paper focuses on the role of material microstructure, including grain boundary density and the presence of inclusions, as well as tool design on surface roughness using the concept of size effect. Size effect can be described as an interplay between the material microstructure dimension and the relative size of the uncut chip thickness with respect to the cutting edge radius. Since one of the controllable parameters in size effect is grain size and dislocation density, controlled studies were performed on samples whose microstructure was refined by mechanical strain hardening through rolling and a friction stir process (FSP). The use of the ultra-fine grained workpiece prepared using an FSP was observed to reduce side flow as well as grain boundary and inclusion induced roughness. The role of tool geometry on material induced roughness was investigated using a tool with a rounded primary cutting edge and a flat secondary edge. The use of the flat secondary edge was observed to improve surface finish when machining a flat surface. This improvement was primarily attributed to a reduction in side flow and material microstructural effects. By combining these approaches an average surface roughness R_a value of 0.685 nm was achieved when SPDT a flat surface. Furthermore the custom tool has the potential to significantly improve the productivity of SPDT by allowing for a much higher feed rate while still achieving a high quality surface finish.     

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正确预测水平井产能对水平井开发方案设计、生产优化及生产动态分析具有重要意义。在充分考虑水平井生产特性的基础上，将水平井看成是由若干段线汇组成，把气体在气藏内向水平井的三维稳态渗流与其在水平井筒内的流动耦合起来，建立了气藏水平井稳态产能计算模型，并提出了求解此模型的方法。实例计算表明：水平井筒内的压力损失对其产能有影响，地层渗透率高时，影响更大；水平井每单位长度的生产指数沿水平井段并非处处都相等。该模型稍作改动，就可用于油藏水平井产能预测。     

高压气井产能评价方法研究

确定气井产能有回压试井、等时试井与修正等时试井，这些方法所需的试井时间长，且增加勘探成本。此外，高压气井试井时开井期井底压力常出现上升现象，有时出现油嘴大（产量高）井底流压也大的现象，导致不能建立产能方程，从而得不到绝对无阻流量。因此，研究高压气井产能评价方法有其必要性。     

利用流压预测供给边界压力的新方法

通过矿场资料的统计分析，探讨、揭示了连续生产油井采油指数的下降规律。在此基础上，建立了利用井底流压、产油量与累积产油量直接预测油井供给边界压力的新方法，本文方法思路清晰、原理正确、充分发挥了流压监测资料的作用，应用实例表明，该方法具有预测精度较高应用简便的特点，可作为常规动态分析方法的重要补充。     

建立企业级BIM生产力需要哪些BIM专业应用人才？

在整个BIM人才结构中,BIM专业应用人才数量最大、覆盖面最广、最终实现BIM业务价值的贡献也最大。没有与企业规模和业务形态相匹配的BIM专业应用人才体系,企业BIM生产力就只能是一句空话。     

The predictive ability of Bromilow's timecost model

Bromilow's log-log time-cost (BTC) model is tested and refitted with a new set of data for Australian construction projects completed between 1991 and 1998. It is shown that, as anticipated by earlier research, different parameter estimates are needed for different project types, with smaller industrial projects taking less time to complete than the smaller educational and residential projects. This results in the development of two separate models, one for industrial projects and one for non-industrial projects. No changes in parameter estimates are needed for projects with different client sectors, contractor selection methods and contractual arrangements. Alternatives to the log-log model failed to produce any improved fit. Finally, the results are compared with previous work to indicate the extent of changes in time-cost relationships in Australian construction projects over the last 40 years. This indicates a clear improvement in construction speed over the period. Furthermore, the ‘public’ sector group in particular has exhibited a greater variation (up to 132%) over the years.     

钢渣尾渣用于烧结的试验研究

在烧结料中配加适当的钢渣尾渣，通过实验室试验，探讨其用于工业性生产的可行性。     

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文章在对气液两相渗流理论调研的基础上，考虑了凝析气藏反凝析和产水的三相流特点，从达西渗流定律入手，根据物质守恒原理，引入气、油、水多相流拟压力，建立了三相流产能方程，给出了无阻流量计算公式，详细描述了根据产能试井数据建立产能方程的步骤。文章提出的方法既适用于地层压力低于露点压力的反凝析气井两相流，也适用于产水凝析气井的三相流，目前气水或油气两相流产能方程只是新方程的特例。对某凝析气藏实际产能试井数据进行了分析计算，表明由于出水凝析气井不仅要克服凝析油的渗流阻力，还要克服水相渗流阻力，多相流产能远远低于单相流，对产水量较大的凝析气井而言，在流动压力大大低于露点压力时，不能采用单相流产能方程配产。实例中的多相流产能曲线表明：在同一井底流压下，随气水比的增加，气体产量将减少；在相同气产量下，随着水气比的增加，生产压差将增大。