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1.
Since the uncertainty involved in demand forecast is increasingly amplified with the forecast lead-time, high-tech companies often suffer the risks of oversupply and shortage of capacity that will affect the profitability and growth. High-tech industries including semiconductor and TFT-LCD industries are capital-intensive, in which the capacity plan and corresponding capital investment decisions are critical due to demand fluctuation. Once the capacity is planned, the company may suffer the risks of either low capital-effectiveness due to low capacity utilization and capacity oversupply, or poor customer satisfaction caused by the capacity shortage. Most of the existing studies focused on solving the long-term capacity shortage issue through optimizing the capacity investment plan, or medium-term capacity plan to allocate demands among the wafer fabrication facilities (fabs) to balance the loading and product mix. Focusing on a real setting, this study proposed a systematic decision method to analyze short-term solutions of cross-company capacity backup between the companies in the semiconductor industry ecosystem. In particular, a game theory and decision tree analysis model was developed to support this decision. A case study was conducted with real data of semiconductor manufacturing companies in Taiwan for validation. The results have demonstrated practical viability of this approach. The approach suggested has been implemented in this company. 相似文献
2.
Vehicle dispatching for highly loaded semiconductor production considering bottleneck machines first
Semiconductor wafer fabrication lines can be characterized by re-entrant product flow, long production lead-time, large variety of production processes, and large capital investment. These distinctive characteristics make the flow control in the fab very complicated. Throughput rate and lead-time are among the most important performance measures. The throughput rate is usually determined by a bottleneck resource, and the lead-time depends on the machine utilization level and the amount of variability in the system. Due to the high efficiency of material handling and reduced particles, automated material handling systems such as automatic guided vehicles (AGVs), overhead hoist transporters (OHTs), and overhead shuttles (OHSs) are being widely used in wafer fabrication lines (wafer fabs) instead of human operators. Although a material handling system itself is seldom a bottleneck of production in a fab, it is important for that to effectively support the bottleneck machines to maximize the throughput and reduce production lead-time. This paper presents a vehicle dispatching procedure based on the concept of theory of constraints, in which vehicle dispatching decisions are made to utilize the bottleneck machines at the maximum level. Simulation experiments have been performed to compare the proposed vehicle dispatching procedure with existing ones under different levels of machine utilization, vehicle utilization, and local buffer capacity. 相似文献
3.
Roger J. Jiao Qianli Xu Jun Du Yiyang Zhang Martin Helander Halimahtun M. Khalid Petri Helo Cheng Ni 《Flexible Services and Manufacturing Journal》2007,19(4):570-595
The fulfillment of individual customer affective needs may award the producer extra premium in gaining a competitive edge. This entails a number of technical challenges to be addressed, such as the elicitation, evaluation, and fulfillment of affective needs, as well as the evaluation of affordability of producers to launch the planned products. Mass customization and personalization have been recognized as an effective means to enhance front-end customer satisfaction while maintaining back-end production efficiency. This paper proposes an affective design framework to facilitate decision-making in designing customized product ecosystems. In particular, ambient intelligence techniques are applied to elicit affective customer needs. An analytical model is proposed to support affective design analysis. Utility measure and conjoint analysis are employed to quantify affective satisfaction, while the producer affordability is evaluated using an affordability index. Association rule mining techniques are applied to model the mapping of affective needs to design elements. Configuration design of product ecosystems is optimized with a heuristic genetic algorithm. A case study of Volvo truck cab design is reported with a focus on the customization of affective features. It is demonstrated that the analytical affective design framework can effectively manage the elicitation, analysis, and fulfillment of affective customer needs. Meanwhile, it can account for the manufacturer’s capabilities, which is vital for ensuring a profit margin in the mass customization and personalization endeavor. 相似文献
4.
Novel PI(4)P 5-kinase homologue, Fab1p, essential for normal vacuole function and morphology in yeast. 总被引:21,自引:10,他引:11
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A Yamamoto D B DeWald I V Boronenkov R A Anderson S D Emr D Koshland 《Molecular biology of the cell》1995,6(5):525-539
The FAB1 gene of budding yeast is predicted to encode a protein of 257 kDa that exhibits significant sequence homology to a human type II PI(4)P 5-kinase (PIP5K-II). The recently cloned human PIP5K-II specifically converts PI(4)P to PI(4,5)P2 (Boronenkov and Anderson, 1995). The region of highest similarity between Fab1p and PIP5K-II includes a predicted nucleotide binding motif, which is likely to correspond to the catalytic domain of the protein. Interestingly, neither PIP5K-II nor Fab1p exhibit significant homology with cloned PI 3-kinases or PI 4-kinases. fab1 mutations result in the formation of aploid and binucleate cells (hence the name FAB). In addition, loss of Fab1p function causes defects in vacuole function and morphology, cell surface integrity, and cell growth. Experiments with a temperature conditional fab1 mutant revealed that their vacuoles rapidly (within 30 min) enlarge to more than double the size upon shifting cells to the nonpermissive temperature. Additional experiments with the fab1 ts mutant together with results obtained with fab1 vps (vacuolar protein sorting defective) double mutants indicate that the nuclear division and cell surface integrity defects observed in fab1 mutants are secondary to the vacuole morphology defects. Based on these data, we propose that Fab1p is a PI(4)P 5-kinase and that the product of the Fab1p reaction, PIP2, functions as an important regulator of vacuole homeostasis perhaps by controlling membrane flux to and/or from the vacuole. Furthermore, a comparison of the phenotypes of fab1 mutants and other yeast mutants affecting PI metabolism suggests that phosphoinositides may serve as general regulators of several different membrane trafficking pathways. 相似文献
5.
Matthew Manahan Michael Nelson Jonathan J. Cacciatore Jessica Weng Sen Xu Jennifer Pollard 《Biotechnology progress》2019,35(6):e2870
Recent advances in high-throughput (HTP) automated mini-bioreactor systems have significantly improved development timelines for early-stage biologic programs. Automated platforms such as the ambr® 250 have demonstrated the ability, using appropriate scale-down approaches, to provide reliable estimates of process performance and product quality from bench to pilot scale, but data sets comparing to large-scale commercial processes (>10,000 L) are limited. As development moves toward late stages, specifically process characterization (PC), a qualified scale-down model (SDM) of the commercial process is a regulatory requirement as part of Biologics License Application (BLA)-enabling activities. This work demonstrates the qualification of the ambr® 250 as a representative SDM for two monoclonal antibody (mAb) commercial processes at scales >10,000 L. Representative process performance and product quality associated with each mAb were achieved using appropriate scale-down approaches, and special attention was paid to pCO2 to ensure consistent performance and product quality. Principal component analysis (PCA) and univariate equivalence testing were utilized in the qualification of the SDM, along with a statistical evaluation of process performance and product-quality attributes for comparability. The ambr® 250 can predict these two commercial-scale processes (at center-point condition) for cell-culture performance and product quality. The time savings and resource advantages to performing PC studies in a small-scale HTP system improves the potential for the biopharmaceutical industry to get products to patients more quickly. 相似文献
6.
Gonchar MV Grabek D Oklejewich B Pavlishko HM Shamlian OV Sybirny VA Kotylak Z Rudke K Csöregi E Sibirny AA 《Ukrainski? biokhimicheski? zhurnal》2005,77(3):146-154
A new enzymo-chemical method for the simultaneous assay of methanol and formaldehyde in mixtures is described which exploits alcohol oxidase (AO) and aldehyde-selective reagent, 3-methyl-2-benzothiazolinone hydrazone (MBTH). The enzyme is used for methanol oxidation to formaldehyde and MBTH plays a double role: 1) at the first step of reaction, it forms a colorless azine adduct with pre-existing and enzymatically formed formaldehyde and masks it from oxidation by AO; 2) at the second step of reaction, non-enzymatic oxidation of azine product to cyanine dye occurs in the presence of ferric ions in acid medium. Pre-existing formaldehyde content is assayed by colorimetric reaction with MBTH without treating samples by AO, and methanol content is determined by a gain in a colored product due to methanol-oxidising reaction. Possibility of differential assay of methanol and formaldehyde by the proposed method has been proved for model solutions as well as for real samples of industrial waste and technical formaline. A threshold sensitivity of the assay method for both analytes is near 1 microM that responds to 30-32 ng analyte in 1 ml of reaction mixture and is 3.2-fold higher when compared to the chemical method with the use of permanganate and chromotropic acid. Linearity of the calibration curve is reliable (p < 0.0001) and standard deviation for parallel measurements for real samples does not exceed 7%. The proposed method, in contrast to the standard chemical approach, does not need the use of aggressive chemicals (concentrated sulfuric, phosphoric, chromotropic acids, permanganate), it is more simple in fulfillment and can be used for industrial wastes control and certification of formaline-contained stuffs. 相似文献
7.
Flexibility of supply and demand is essential for successful implementation of a mass customization strategy that delivers sustained competitive advantage. Supply flexibility, i.e., a choice of alternative products designed to perform the same basic function, is made possible by the range of capabilities available in flexible and agile manufacturing systems and in supply chains. Demand flexibility is derived from the degree to which a customer is willing to compromise on product features or performance levels in order to meet budgetary (reflected in price) or schedule (reflected in delivery) constraints. Flexibility of both supply and demand can have significant strategic and financial value if they are properly aligned. However, customers are mostly unaware of mapping of demand flexibility on to supply flexibility and its impact on production cost and time. Recent advances in information technology have made it possible to co-design a product that involves customer on one end and the manufacturer on the other. This creates an aura and an opportunity where a middle ground between the supply and demand flexibility can be explored and a “deal” can be struck where both parties settle for a product that is beneficial to both through a negotiated settlement. In this paper, we develop a framework for such negotiations. The customer requirements are treated as a range of negotiable options instead of a set of fixed inputs. Demand and supply for customization is then matched by aligning the flexibility of manufacturing systems with customers’ requirement options. Based on this framework, a negotiation scheme is developed to assist customers and manufacturers in exploring and utilizing demand and supply flexibility information in co-design. The negotiation scheme is formulated using goal programming. Finally, an interactive problem-solving procedure is developed and implemented with an illustrative example. 相似文献
8.
9.
Jaejin Jang Jaewoo Chung Jungdae Suh Jongtae Rhee 《Flexible Services and Manufacturing Journal》2006,18(2):121-144
To a customer, the waiting time for order processing for a product or service is important information for order placement. If the time foreseen for order fulfillment is long, the order might be lost to a competitor. In particular, modern principles of supply chain management highly suggest information sharing between entities in the chain and information technology has enabled customers to conveniently consider the waiting time for a potential balking decision. To help determine the design and operation of a manufacturing or service system in which a customer may balk based on the foreseen waiting time, this paper develops procedures to estimate the average waiting time of an order. Either the procedures allow the maximum waiting time for a balking decision to be random or do not require knowledge of the arrival process of customers before balking if the balking limit is known. For generality of the model, this paper considers general inter-arrival and service time distributions, and uses the simulation and regression approach. 相似文献
10.
The bioremediation of aqueous wastes containing 5-nitro-1,2,4-triazol-3-one (NTO) was investigated. The microorganism used is a Bacillus licheniformis strain, isolated from the contaminated solutions by enrichment techniques. The biodegradation was carried out in the waste (15 g l-1 NTO) and proceeded through the nitroreduction of NTO, followed by the ring cleavage of the formed primary amine 5-amino-1,2,4-triazol-3-one (ATO). Both steps were optimized and according to the optimal conditions, the nitroreduction of NTO is total in 24 h, while the degradation of ATO requires 2 weeks of incubation. The end products of the biodegradation were carbon dioxide (40%), urea and a polar compound, assumed to be hydroxyurea. A mechanism of ATO ring cleavage was postulated in the light of experimental data, and led us to propose an overall degradation sequence for NTO. 相似文献
11.
Sarlauskas J Nemeikaite-Ceniene A Anusevicius Z Miseviciene L Maroziene A Markevicius A Cenas N 《Zeitschrift für Naturforschung. C, Journal of biosciences》2004,59(5-6):399-404
The toxicity of conventional nitroaromatic explosives like 2,4,6-trinitrotoluene (TNT) is caused by their enzymatic free radical formation with the subsequent oxidative stress, the formation of alkylating nitroso and/or hydroxylamino metabolites, and oxyhemoglobin oxidation into methemoglobin. In order to get an insight into the mechanisms of toxicity of the novel explosives NTO (5-nitro-1,2,4-triazol-3-one) and ANTA (5-nitro-1,2,4-triazol-3-amine), we examined their reactions with the single-electron transferring flavoenzymes NADPH: cytochrome P-450 reductase and ferredoxin:NADP+ reductase, two-electron transferring flavoenzymes mammalian NAD(P)H:quinone oxidoreductase (DT-diaphorase), and Enterobacter cloacae NAD(P)H:nitroreductase, and their reactions with oxyhemoglobin. The reactivity of NTO and ANTA in the above reactions was markedly lower than that of TNT. The toxicity of NTO and ANTA in bovine leukemia virus-transformed lamb kidney fibroblasts (line FLK) was partly prevented by desferrioxamine and the antioxidant N,N'-diphenyl-p-phenylene diamine, and potentiated by 1,3-bis-(2-chloroethyl)-1-nitrosourea. This points to the involvement of oxidative stress in their cytotoxicity, presumably to the redox cycling of free radicals. The FLK cell line cytotoxicity and the methemoglobin formation in isolated human erythrocytes of NTO and ANTA were also markedly lower than those of TNT, and similar to those of nitrobenzene. Taken together, our data demonstrate that the low toxicity of nitrotriazole explosives may be attributed to their low electron-accepting properties. 相似文献
12.
Bansal SK Layloff T Bush ED Hamilton M Hankinson EA Landy JS Lowes S Nasr MM St Jean PA Shah VP 《AAPS PharmSciTech》2004,5(1):151-158
The purpose of the use of analytical instruments is to generate reliable data. Instrument qualification helps fulfill this
purpose. No authoritative guide exists that considers the risk of instrument failure and combines that risk with users' scientific
knowledge and ability to use the instrument to deliver reliable and consistent data. In the absence of such a guide, the qualification
of analytical instruments has become a subjective and often fruitless document-generating exercise.
Taking its cue from the new FDA initiative, “Pharmaceutical GMP's for the 21st Century,” an efficient, science- and risk-based
process for AIQ was discussed at a workshop on analytical instrument qualification. This report represents the distillate
of deliberations on the complicated issues associated with the various stages of analytical instrument qualification. It emphasizes
AIQ's place in the overall process of obtaining quality reliable data from analytical instruments and offers an efficient
process for its performance, one that focuses on scientific value rather than on producing documents. Implementing such a
process should remove ambiguous interpretations by various groups. 相似文献
13.
Steven M. Gray Lisa J. Faust Paul Senner Kristine S. Eebes Judy P. Che-Castaldo 《Zoo biology》2023,42(1):142-149
Compliance with Breeding and Transfer Plan (BTP) recommendations is important to promote long-term viability and meet the management goals of the Association of Zoos and Aquarium Species Survival Plans (SSPs®). However, individual institutions may fulfill recommendations at different rates, potentially compromising management efforts. We examined institution-level fulfillment rates of BTP recommendations (i.e, “Hold,” “Send To,” “Breed With,” and “Do Not Breed”), and how rates differ based on institutional attributes related to resource levels, geographic location and climate, involvement in population management, and the SSPs in which institutions participated using conditional random forests and generalized linear mixed models. We analyzed 52,182 recommendations from 375 SSPs issued to 170 institutions in BTPs published from 2012 to 2019. Contrary to predictions, our results did not reveal large differences in fulfillment rates based on resources, geographic location, or climate variables at the institution level. We found modest patterns indicating that recommendation fulfillment for Hold and Do Not Breed recommendations in mammals was lower with longer interplanning periods, while fulfillment of Hold recommendations in birds increased with the average experience of individuals in SSP leadership roles. For herptiles, fulfillment of Send To recommendations was moderately higher in institutions with species spread across more herptile taxonomic advisory groups (the management unit for related species). Although our results suggest that overarching institutional factors do not have a strong influence on fulfillment rates at the scale of our study, more focused research within a specific temporal window, taxa, or suite of SSPs may reveal more informative patterns for population management. 相似文献
14.
A multistage exercise test was carried out in normotensive subjects with normotensive parents (controls; n = 12), and 32 offspring of essential hypertensive patients that were normotensive (NTO; n = 20) or borderline hypertensive (BHO; n = 12) The groups were comparable as to age, weight and working capacity. Changes in sympathetic nervous activity were determined by measurements of plasma noradrenaline. The initial rise in noradrenaline levels during the exercise test was proportional to the increase in work load until the noradrenaline concentration rose sharply to levels more than 1000 pg/ml above baseline levels. The work load immediately prior to the steep rise in plasma noradrenaline (sympathetic threshold level: STL) is considered to represent the point from which anaerobic energy-yielding processes play an increasingly greater role as the work load increases. The initial increase in plasma noradrenaline until STL was significantly higher in both the NTO (p less than 0.02) and BHO (p less than 0.005) compared to the control group. The absolute noradrenaline level at STL and the increase in noradrenaline from baseline to STL were significantly higher in the BHO group (p less than 0.02, p less than 0.005). No significant differences between the groups were found when comparing noradrenaline levels at rest or at absolute or relative work loads. The systolic blood pressure response during the exercise test was significantly more pronounced in the BHO group (p less than 0.05) compared to the controls and the NTO group. 相似文献
15.
J. R. Waaland 《Journal of phycology》2002,38(Z1):36-36
The red alga Chondracanthus exasperatus is a source of the phycocolloid carrageenan as well as an ingredient referred to as ‘intralamellar gel’ in a recently developed cosmetic formula (US Patent 6136 329). The high value of the cosmetic product has sparked renewed interest in cultivation of this species. Previous cultivation methods for this species include open water culture on nets and immersed cultivation in tanks supplied with flow‐through pumped seawater. The installation of a high capacity seawater supply, pumping and drain system is a major cost for flow through systems. Recirculating or re‐use seawater systems that minimize seawater turnover may offer significant cost savings over single‐pass, flow through seawater systems. In this research several options for minimizing seawater use have been tested: recirculating batch culture in which nutrient replenished (carbon dioxide and mineral nutrients) natural or artificial seawater is used with minimal turnover and spray culture in which plants are suspended in air saturated with nutrient replenished natural or artificial seawater medium. Small volume (<2 L), single‐plant bioreactors and larger multiplant, 20, 80 and 320 L (sea water volume) immersion and spray systems have been developed and tested. Results from these systems will be presented. Research supported by Washington Sea Grant, Washington Biotechnology Center and Soliv International Corporation. 相似文献
16.
选择容量价值:一个新的生态系统服务价值指标 总被引:1,自引:0,他引:1
对生态系统服务进行价值评估有助于落实生态系统的科学管理和推动生态补偿的科学实施。然而,传统的生态系统服务价值评估方法在管理实践应用中存在明显的局限性。为了规避这些局限性,另辟一条对生态系统服务价值评估的新思路,提出了描述生态系统服务价值的新指标——"选择容量价值"。选择容量价值以两个事实为基本依据:1)如果失去了任何一项生存所必需的生态系统服务(比如氧气、水),那么人类就无法生存,亦即人类经济社会活动所产生的价值是建立在消费该生态系统服务的基础上的;2)如果没有人类活动的存在,那么生态系统就给人类提供不了任何价值,亦即生态系统服务价值的度量是建立在生态系统服务所支持的人类经济社会活动所产生的价值上的。选择容量价值是指,一项人类生存生产所必需的生态系统服务,其总量为消费该生态系统服务的消费活动所提供的选择自由度(即选择容量)与该消费活动所产生的经济社会活动总价值的乘积,用非货币单位来计量。通过一个案例——对珠江流域的水资源供应的选择容量价值的估算,揭示选择容量价值对理解和量化生态系统服务价值的新洞察。结果显示,选择容量价值能够直观而综合地反映生态系统服务总量、生态系统服务消费量、社会经济... 相似文献
17.
Fixed performance oxygen masks operate by supplying mixtures of oxygen and air at rates exceeding the inspiratory flow rate of the patient. In this study the oxygen concentration delivered by three fixed performance oxygen masks was determined non-invasively at various inspiratory flow rates. At low inspiratory flow rates all the masks studied acted as fixed performance devices. When the peak inspiratory rate increased the performance of all the masks showed some variability. The change from fixed to variable performance depended on the relation between inspiratory flow rate and the total gas flow delivered by the mask and was independent of the volume of the mask. Hence the use of low volume masks and high oxygen flow rates should produce more consistent results than high volume masks and lower flow rates. 相似文献
18.
Noaki Morita Akio Ueno Mika Tamaka Satoru Ohgiya Tamotsu Hoshino Kosei Kawasaki Isao Yumoto Kozo Ishizaki Hidetoshi Okuyama 《Biotechnology letters》1999,21(7):641-646
A cluster of genes involved in fatty acid biosynthesis (fab) was isolated from docosahexaenoic acid (DHA)-producing Vibrio marinus strain MP-1. This fab gene cluster included five genes highly homologous to the Escherichia coli counterparts, and their order in the cluster was the same with that of the E. coli fab gene cluster except that the latter included the additional fabH gene. These fab genes should be involved in early steps of DHA biosynthesis in V. marinus strain MP-1. 相似文献
19.
This work is a study of 5-amino-3-nitro-1,2,4-triazole (ANTA), 3-nitro-1,2,4-triazol-5-one (NTO), and nitrated derivatives of ANTA and NTO. RDX and TNT were studied for comparison. ANTA and NTO are low-sensitive high explosives with detonation properties comparable to 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitroperhydro-1,3,5-triazine (RDX). We showed previously that nitrated NTO and ANTA compounds, when used in a glycidyl azide polymer (GAP) matrix in rocket propellants, could give impulses above 2600 m/s and that the oxygen balance is positive. If used in aluminized explosives, the heat of detonation may be increased to a practical level significantly above RDX/aluminum compositions. Here, we use two different methods for sensitivity and two density functional theory functionals, B3LYP and M06-2X with the 6-31G(d) basis set, together with the complete basis set method CBS-4M. Calculations indicate that most of the nitrated derivatives have nearly equal sensitivity to RDX. Significantly different bond dissociation energies in the nitrimino functional group are predicted, although most models give much the same result. 相似文献
20.
A KAS2 cDNA complements the phenotypes of the Arabidopsis fab1 mutant that differs in a single residue bordering the substrate binding pocket 总被引:1,自引:0,他引:1
Carlsson AS LaBrie ST Kinney AJ von Wettstein-Knowles P Browse J 《The Plant journal : for cell and molecular biology》2002,29(6):761-770
The fab1 mutant of Arabidopsis is partially deficient in activity of beta-ketoacyl-[acyl carrier protein] synthase II (KAS II). This defect results in increased levels of 16:0 fatty acid and is associated with damage and death of the mutants at low temperature. Transformation of fab1 plants with a cDNA from Brassica napus encoding a KAS II enzyme resulted in complementation of both mutant phenotypes. The dual complementation by expression of the single gene proves that low-temperature damage is a consequence of altered membrane unsaturation. The fab1 mutation is a single nucleotide change in Arabidopsis KAS2 that results in a Leu337Phe substitution. The Leu337 residue is conserved among plant and bacterial KAS proteins, and in the crystal structures of E. coli KAS I and KAS II, this leucine abuts a phenylalanine whose imidazole ring extends into the substrate binding cavity causing the fatty acid chain to bend. For functional analysis the equivalent Leu207Phe mutation was introduced into the fabB gene encoding the E. coli KAS I enzyme. Compared to wild-type, the Leu207Phe protein showed a 10-fold decrease in binding affinity for the fatty acid substrate, exhibited a modified behavior during size-exclusion chromatography and was severely impaired in condensation activity. These results suggest that the molecular defect in fab1 plants is a structural instability of the KAS2 gene product induced by insufficient space for the imidazole ring of the mutant phenylalanine residue. 相似文献