A model for labour pooling in batch manufacturing

Cross-training workers to perform multi-skilled jobs is one of the modern trends in job design. As companies engage in downsizing, the remaining workforce is expected to do more and different tasks. This paper presents a formal definition and a practical solution for optimizing the size and cost of the pool of multi-skilled workers for production units operated under batch manufacturing. The pool size is optimized through a search procedure applied separately to just-in-time (JIT) and level production plans, which are derived from the stones heuristic. The method allows direct calculation of the cost savings from labour pooling. This paper was inspired by consulting in the food industry, where implementation of these results has significantly reduced labour costs.     

Requirement estimation for indirect workforce allocation in semiconductor manufacturing

This work, based on a real case, presents a model to estimate indirect workforce requirements of semiconductor fabrication facilities (fabs) so that the workforce can be fairly allocated. There is a concern in a real setting to fairly allocate the overall corporate workforce among the fabs, particularly when they compete in performance, and properly determining the actual requirement is the most critical in the decision process. The actual requirements of the workforce, especially the indirect workforce, for fabs may be indeterminate due to the lack of a well-defined workforce-output relationship. This paper presents a non-parametric frontier approach for estimating the indirect workforce, and the estimate is based on the best past performance adjusted to reflect the expected productivity growth. An empirical study was conducted in a leading foundry in Taiwan that has a number of 8-inch fabs. The proposed (re)allocation approach can provide an explicit decision support mechanism to balance the workloads in light of various production environments to enable an equitable basis for performance evaluation to foster constructive competition among the fabs.     

A site selection model for high technology manufacturing firms in the United States

This article offers a quantitative model for site selection by high technology manufacturing firms. In the past, site selection studies have usually been qualitative in nature, and very subjective. This is an attempt to introduce a more objective quantitative approach. The site selection factors most important to high technology manufacturing firms were identified, ranked and weighted based on a US Joint Economic Committe survey of such firms. The eight most important factors were: the availability of technical and professional workers, labor costs, tax climate, academic institutions, cost of living, transportation for people, and access to markets. Demographic data on these factors were collected and analyzed for 32 developing high technology areas in the United States. By using the quantitative model, a score was developed for each area, allowing them to be ranked as R & D manufacturing environments. This model should prove a useful tool for both regional planners and high-tech companies seeking to relocate.     

直接蒸发冷却空调机组应用于高湿度地区的性能测试

为了研究直接蒸发冷却空调机组在浙江某核电站应用的可行性,在与该核电站室外设计条件相似的南通市对一台55 000 m3/h风量的金属填料型直接蒸发冷却空调机组进行性能测试。试验结果表明,直接蒸发冷却空调机组的平均温降为4.1℃,平均冷却效率为91.2%,满足风量和机外余压的要求。这说明直接蒸发冷却空调机组应用于此核电站是可行的。     

Work sequencing in a manufacturing cell with limited labour constraints

This study focuses on the analysis of group scheduling heuristics in a dual-constrained, automated manufacturing cell, where labour utilization is limited to setups, tear-downs and loads/unloads. This scenario is realistic in today's automated manufacturing cells. The results indicate that policies for allocating labour to tasks have very little impact in such an environment. Furthermore, the performance of efficiency oriented, exhaustive, group scheduling heuristics deteriorated while the performance of the more complex, non-exhaustive heuristics improved. Thus, it is recommended that production managers use the simplest labour scheduling policy, and instead focus their efforts to activities such as job scheduling and production planning in such environments.     

Predicted modifications in the direct and indirect gaps of Ge

The charge density of Ge was studied at various k-points and for various bands, by the ab initio pseudopotential method, using additionally the interstitial sites. The lowest X_c conduction-band points were found to be unique in having a high charge density in the interstitial site. It has been therefore predicted and verified that the X_c points move up in energy relative to the Γ_c point when closed-shell atoms (like H) are substituted at the interstitial sites. The calculations also indicate the change of the band-gap for HGeH.     

STEP-based approach for direct slicing of CAD models for layered manufacturing

Direct slicing can generate precise slice contours from original CAD models and obviates the error-detection and repairing process of STL files. At present, most direct slicing approaches are restricted to some CSG solids or particular CAD packages. In this paper, an approach for direct slicing of CAD models based on STEP for layered manufacturing is presented. The original CAD model is first transferred from CAD systems to the slicing system by neutral STEP files. Using OpenGL graphics libraries, the solid model is then displayed, and the user is prompted to specify the layer thickness. Finally, the CAD model is sliced directly, and the sliced model is exported by SSL (Stratasys Layer interface files) file format which can be sent to many kinds of layered manufacturing systems for direct fabrication. The approach of STEP-based direct slicing is more flexible and does not rely on any specific CAD system; in addition, the STEP files are much smaller than the STL files. Implementation details and results are also presented.     

现代制造哲理中的成组技术

本文主要探讨成组技术与现代制造系统的一些哲理关系，本文的研究表明，成组技术是现代制造系统的基础和共性的技术，成组技术不应作为一门独立的技术应用，而应与其它系统生产技术综合使用。     

Spatial mapping of droplet velocity and size for direct and indirect nebulization in plasma spectrometry

Two novel laser-based imaging techniques centered on particle image velocimetry and optical patternation are used to map and contrast the size and velocity distributions for indirect and direct pneumatic nebulizations in plasma spectrometry. The flow field of droplets is illuminated by two pulses from a thin laser sheet with a known time difference. The scattering of the laser light from droplets is captured by a charge-coupled device (CCD), providing two instantaneous images of the particles. Pointwise cross-correlation of the corresponding images yields a two-dimensional velocity map of the aerosol velocity field. For droplet size distribution studies, the solution is doped with a fluorescent dye and both laser-induced florescence (LIF) and Mie scattering images are captured simultaneously by two CCDs with the same field of view. The ratio of the LIF/Mie images provides relative droplet size information, which is then scaled by a point calibration method via a phase Doppler particle analyzer. Two major findings are realized for three nebulization systems: (1) a direct injection high-efficiency nebulizer (DIHEN); (2) a large-bore DIHEN; and (3) a PFA microflow nebulizer with a PFA Scott-type spray chamber. First, the central region of the aerosol cone from the direct injection nebulizers and the nebulizer-spray chamber arrangement consists of fast (>13 and >8 m/s, respectively) and fine (<10 and <5 microm, respectively) droplets as compared to slow (<4 m/s) and large (>25 microm) droplets in the fringes. Second, the spray chamber acts as a momentum separator, rather than a droplet size selector, as it removes droplets having larger sizes or velocities. The concepts and results presented in this research may be used to develop smart-tunable nebulizers, for example, by using the measured momentum as a feedback control for adjusting the nebulizer, i.e., its operating conditions, its critical dimensions, or both.     

Relation between the accuracies of direct and indirect measurements

Translated from Izmeritel'naya Tekhnika, No. 5, pp. 9–10, May, 1988.     

Advances in solid dosage form manufacturing technology

Currently, the pharmaceutical and healthcare industries are moving through a period of unparalleled change. Major multinational pharmaceutical companies are restructuring, consolidating, merging and more importantly critically assessing their competitiveness to ensure constant growth in an ever-more demanding market where the cost of developing novel products is continuously increasing. The pharmaceutical manufacturing processes currently in existence for the production of solid oral dosage forms are associated with significant disadvantages and in many instances provide many processing problems. Therefore, it is well accepted that there is an increasing need for alternative processes to dramatically improve powder processing, and more importantly to ensure that acceptable, reproducible solid dosage forms can be manufactured. Consequently, pharmaceutical companies are beginning to invest in innovative processes capable of producing solid dosage forms that better meet the needs of the patient while providing efficient manufacturing operations. This article discusses two emerging solid dosage form manufacturing technologies, namely hot-melt extrusion and fluidized hot-melt granulation.     

Standardised product development for technology integration of additive manufacturing

ABSTRACT

The implementation of additive manufacturing (AM) as an industrial production process poses extraordinary challenges to companies due to the far-reaching differences to conventional processes. In addition, there are hardly any standards and guidelines or methodical process models for the relatively new technologies that enable the reproducible and target-oriented use of AM. In order to solve this problem, five industrial companies together with the Paderborn University are researching as part of the ‘OptiAMix’ research project funded by the Federal Ministry of Education and Research (BMBF). This paper focuses on the development of an ideal process chain. Reference processes of the OptiAMix partners were analysed, norms and standards from conventional production were adapted and implemented and procedure models developed OptiAMix were integrated. The resulting AM Product Development Process was then applied and validated with the aid of a previously developed integration methodology using an example component from the automotive industry.     

Relative importance of contingency variables for advanced manufacturing technology

The academic literature on manufacturing technology was reviewed to identify key contingency variables that can moderate the influence of advanced manufacturing technologies on manufacturing performance. Using this literature as a basis, this research proposes an ordering of relative importance of individual contingency variables among a set of contingency variables that influence the advanced manufacturing technologies–manufacturing performance relationship. Plant level data from a large multi-industry sample of firms are analysed, using regression and Chow tests, to confirm the hypothesized ordering among the contingency variables. The findings indicate that lean manufacturing and work organization practices are the primary contingency variables that affect the advanced manufacturing technologies–manufacturing performance relationship. The implications of the results are discussed in the light of past findings and their impact on practice.     

The effect of chromium coating in RP technology for airfoil manufacturing

Most wind tunnel models are fabricated of all metal components using computerized numerical control (CNC) milling machines. Fabrication of metal wind tunnel models is very expensive and time consuming. The models can require months to manufacture and are often made by small high technology companies that specialize in wind tunnel model manufacture. Using rapid prototype manufacturing techniques and materials in this way significantly reduces time and cost of production of wind tunnel models. This study was done by fused deposition modelling and their ability to make components for wind tunnel models in a timely and cost effective manner. This paper discusses the application of wind tunnel model configuration constructed using FDM and FDM with chromium coating for subsonic wind tunnel testing. A study was undertaken comparing a rapid prototyping model constructed of FDM technologies using polycarbonate to that of a standard machined steel model. Results from this study show relatively good agreement among the three models and rapid prototyping method with chromium coating does have an effect on the aerodynamic characteristics which produced satisfactory results.     

跨入21世纪的先进光学制造技术

以21世纪的光学、光学工程和先进制造技术两大领域不断深化的学科交叉及其发展趋势为背景,从更高和更宽的视角上讨论先进光学制造技术的跨世纪发展。指出“一大一小”引领着先进光学制造技术的发展主流。先进光学制造技术应该在自然科学的学科体系中占有一席之地。     

制造服务化与膜技术应用

服务化是当今世界制造业的发展趋势之一.文章对制造服务化的基本概念、内涵及途径进行了较详细的分析.制造服务化的核心内容就是以客户需求为导向,实现从生产为中心向服务为中心的转化.文章还讨论了制造服务化趋势对膜制造产业发展和膜技术应用的重要启示.     

中国散裂中子源小型非直冷式低温恒温器技术

中国散裂中子源(CSNS)中国自主建设的第一台散裂中子源,CSNS一期工程需设计并配置3套以上的小型低温恒温器。介绍了CSNS小型非直冷式低温恒温器及系统设计、系统控制设计以及测试结果,获得了该恒温器内真空腔的真空度、样品管氦气压力与温度之间的变化关系,为低温恒温器的设计和在CSNS应用中的运行维护提供了理论依据。