Effectivity date analysis and scheduling

The impact of design on logistics cannot be ignored, and design for logistics is a new concept similar to design for manufacturing or design for assembly. Engineering change is one of the scenarios that would require logistics support. Change control of a product data management (PDM) system is one of the major approaches for handling engineering changes today. According to principles of configuration management, during the change control workflow, there are three different dates: release date, effective date, and effectivity date utilised for controlling and managing change planning and scheduling. Effective date is the exact date that a released change takes effect to the shop floor workshop. Effectivity date is the expected date that decision makers plan for the change to take effect. In normal situations, multiple disciplines, such as design and development, purchasing, shop floor workshop, quality control, and so on, are involved in making a change decision on when a change is to become effective. In this paper, a linear programming effectivity decision model is proposed to concurrently support changes of design scheduling, and production planning and scheduling when an engineering change occurs. The proposed model succeeded in solving an integration problem of design scheduling, production planning and shop floor scheduling.     

Benchmarking and analysis of superscalar architecture

Abstract

Superscalar processing can improve the performance of a single CPU beyond that of traditional RISC machines by exploiting instruction‐level parallelism. It is the objective of this study to design a superscalar system which will best exploit a given program's instruction‐level parallelism.

Three different architectural models, XPCB, XXPB, and X4P2, are used as vehicles in evaluating system performance and the degree of utilization of each individual functional unit. The XPCB model is used as a preliminary model to analyze the loading breakdowns of the various function types. It was found that the performance improvement of the XPCB model relative to a single‐instruction stream model is only about 4.3 percent. In addition, the fixed‐point operations are in great demand, and dominate the behavior as well as performance of the processor. Two enhanced models, the XXPB and the X4P2, are suggested to improve on the performance of the XPCB model by distributing fixed‐point, and even floating‐point operation loads among multiple functional units of the same type(s). Simulations show that the XXPB and X4P2 models can improve the performance of the sequential model by 50.8 and 61.6 percent, respectively.     

The structure of the Reynolds stress in a turbulent flow over windbreaks of half‐circular sections

Abstract

The structure of the Reynolds stress in a turbulent flow over the multiple windbreaks of half‐circular sections across‐wind was investigated experimentally in the boundary layer wind tunnel. The quadrant analysis theory was applied to analyze the turbulent stress signals by partitioning the Reynolds stress into inward interaction, ejection, outward interaction, and sweep events in accordance with whichever quadrant the (u’, w‘)belongs to. u’ and w’ are the stream wise and transversewise velocity fluctuations, respectively The results show that when Z/H < 1, X/H < 20, the sweep events are the largest contributors to the Reynolds stress followed by the ejection events while the inward and outward interactions are negative contributors. Z is the distance from the wall, X is the downstream distance, and H is the height of windbreak. The stress contributions by sweeps and ejections are almost the same when Z/H < 1, X/H > 30.     

Capability assessment for processes with multiple characteristics: A generalization of the popular index Cpk

Process capability index C_pk is the most popular capability index widely used in the manufacturing industry. Existing research on the yield‐based measure index C_pk to date is restricted to processes with single characteristics. However, many manufacturing processes are commonly described with multiple characteristics, for example, the gold bumping process in the TFT‐LCD (thin film transistor‐liquid crystal display) manufacturing industry. In the gold bumping process, gold bumps have multiple characteristics all having effects on the process yield. Obtaining accurate gold bumping manufacturing yield is very important for quality assurance and in providing guidance toward process improvement. To obtain accurate yield assessment for processes with multiple characteristics, we propose a new overall yield‐measure index C, which is a generalization of the index C_pk, and a natural estimator of C. For the purpose of making inferences on the process capability, we derive a quite accurate approximation of the distribution of since the distribution is analytically intractable. With this distribution, we tabulate the lower confidence bounds of the new index under various sample sizes for in‐plant applications. In addition, we construct a statistical test on the new yield‐measure index in order to examine whether the yield meets the customers' requirements. For illustration purpose, a real case in a gold bumping factory located in the Science‐based Industrial Park at Hsinchu, Taiwan is presented. Copyright © 2011 John Wiley & Sons, Ltd.     

Combined column generation and constructive heuristic for a proportionate flexible flow shop scheduling

In a proportionate flow shop problem, jobs have to be processed through a fixed sequence of machines, and processing time for each job is equal on all machines. Such a problem has seldom been tackled. Proportionate flexible flow shop (PFFS) scheduling problems combine the properties of proportionate flow shop scheduling problems and parallel machine scheduling problems. This study presents a combined approach based on column generation (CG) for a PFFS problem with the criterion to minimize the objective of the total weighted completion time (TWCT). Minimizing TWCT in a PFFS problem significantly differs from the parallel-identical-machine scheduling problem, an optimal schedule in which jobs on each machine are in the weighted shortest processing time (WSPT) order. This combined approach adopts a CG approach to effectively handle job assignments to machines, and a constructive heuristic to obtain an optimal sequence for a single machine. Experimental results show the effectiveness of the combined approach in obtaining excellent quality solutions in a reasonable time, especially for large-scale problems.     

冷家油田储层成岩作用及对孔隙演化的影响

利用各种分析化验手段研究了辽河冷家油田冷43断块稠油油藏S1+2段砂砾岩储层的成岩作用特征，建立了储层的成岩演化模式，研究了储层的孔隙类型，定量分析了储层成岩作用对储层孔隙演化的影响，为冷43断块油藏描述提供了成岩模型和孔隙演化模型。     

Identification of species and measurement of tetrodotoxin in dried dressed fillets of the puffer fish,Lagocephalus lunaris

The toxicity and species of dried dressed fish fillets were investigated. Three of seven dried dressed fish fillets were found to be toxic, with their levels of toxicity ranging from 9 to 18 mouse units per g. The toxin preparation was further purified and identified as tetrodotoxin and anhydrotetrodotoxin by high-performance liquid chromatography and gas chromatography-mass spectroscopy. The species of these fillets could not be distinguished from Lagocephalus lunaris by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis or restriction site and sequence analysis of a polymerase chain reaction amplicon of the cytochrome b gene. These fish fillets were identified as L. lunaris on the basis of their protein patterns and gene characteristics. Furthermore, the toxic samples contained low levels of tetrodotoxin and its derivative.     

Variant antibody identification by peptide mapping

During development of CGP56901, a monoclonal antibody (MAb) specific for a unique epitope on human IgE, the protein A-purified IgG from one of the candidate production cell lines, showed an additional minor heavy chain (H-chain) band with a molecular weight slightly lower than that of the principal H-chain band on SDS-PAGE. The N-terminal amino acid sequence of this minor H-chain species indicated that at least the first 30 amino acids were identical to those of the antibody light-chain (L-chain) variable domain. More detailed studies using peptide mapping and amino acid sequencing analysis confirmed a crossover event between the V genes of the antibody. The position is between Arg108 of the L chain and Ala124 of the H chain. This crossover resulted in a variant H chain, which had 16 fewer amino acid residues than the normal CGP56901 H chain. These results show that peptide mapping is a useful "first-line" analytical tool in the characterization of the quality of the monoclonal antibody.