• 제목/요약/키워드: Cell formation

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셀형 유연조립시스템에서의 통합 배치설계 (Integrated Layout Design in Cellular Flexible Assembly Systems)

  • 최영호;노인규
    • 한국경영과학회지
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    • 제22권4호
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    • pp.133-149
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    • 1997
  • The major two steps required to design a cellular layout are cell formation and cell layout. Because of the differences between manufacturing and assembly operations, the logic of cell formation and cell layout between an FMS and an FAS is not the same. Since the time for the assembly operations is usualaly relatively short, the transfer time is thus very crucial for the performance of assembly systems. Transfore in a cellular FAS it is more important to eliminate backtracking operations in assembly planning, not to allow intercellular movements in cell formation, and to arrange machines according to assembly sequence in cell layout. This study presents a method for the integrated layout design in cellular FASs considering the characteristics of FAS, layout, and production factors.

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가공순서가 주어진 새로운 제조셀 형성방법 (A New Approach for Manufacturing Cell Formation with Operation Sequences)

  • 최동순;정병희
    • 산업경영시스템학회지
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    • 제21권46호
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    • pp.59-72
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    • 1998
  • This study is concerned in manufacturing cell formation with operation sequences. Operation sequences must be reflected for manufacturing cell formation anyway, because the primary aim of cellular manufacturing system is to minimize the inter-cell flows, and inter-cell flows are differed by operation sequences. In this study we propose flow-similarity(FS) of reflecting both inter-machine similarity and direct/indirect flow, and then apply the modified P-median model for grouping machines. We also use machine cell-part handling frequency(CPH) so as to be assigned parts to the machine cells having the most CPH. We confirm this approach through an application example. The performance of this approach(FS-model) is evaluated and compared with P-median model and F-model through computational experiments.

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유전 알고리듬에 기초한 제조셀과 셀 배치의 설계 (Design of Manufacturing Cell and Cellular Layout based on Genetic Algorithm)

  • 조규갑;이병욱
    • 산업공학
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    • 제14권1호
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    • pp.20-29
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    • 2001
  • This paper presents a concurrent design approach that deals with manufacturing cell formation and cellular layout in Cellular Manufacturing System. Manufacturing cell formation is to group machines into machine cells dedicated to manufacture of part families, and cellular layout problem determines layout of the manufacturing cells within shop and layout of the machines within a cell. In this paper, a concurrent approach for design of machine cell and cellular layout is developed considering manufacturing parameters such as alternative process plans, alternative machines, production volume and processing time of part, and cost per unit time of operation. A mathematical model which minimizes total cost consisting of machine installation cost, machine operating cost, and intercell and intracell movements cost of part is proposed. A hybrid method based on genetic algorithm is proposed to solve the manufacturing cell formation and cellular layout design problem concurrently. The performance of the hybrid method is examined on several problems.

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Chlorella와 Scenedesmus 세포 함유물질이 Lactobacillus delbrukii 와 Bacillus subtilis 에 미치는 성장 촉진효과 (Stimulating effects of Chlorella and Scenedesmus cell upon the growth and fermentation of L. delbrukii and B. subtilis)

  • 정지원;이태우;이주식
    • 미생물학회지
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    • 제6권1호
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    • pp.12-21
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    • 1968
  • The accelerate effects on the growth rate and the capacity of fermentation of L. delbrukii and B. subtilis was investigated in the Henneberg's medium added by various amounts of cellular components of Chlorella and Scenedesmus and also was investigated in the media added micronutritional elements such as Mn, Fe and Mo, etc. The results in the comparative experiments are as follow; 1. Various amounts of Chlorella cell components in the media accelerated remarkably the lactic acid formation and growth of L. delbrukii. For example, lactic acid formation in the medium of contained 1 percent Chlorella cell components was promoted more than twice effects compare with control. 2. The formation of .alpha.-amylase by B. subtilis in the medium of 2 percent Chlorella cell contents was also promoted more than nine twice effects compare with control. 3. The formation of lactic acid of L. delbruckii in the medium of Scenedesmus cell contents was a little more than in the medium of Chlorella cell contents. 4. The lactic acid fermented level attained with the addition of 0.2-0.25 percent Chlorella cells was the effect of promoting fermentation attained of saturating level at 100$\mu$g. /ml. of Mn and 0. 1 $\mu$g./ml. of Fe.

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Methanolic Extract Isolated from Root of Lycoris aurea Inhibits Cancer Cell Growth and Endothelial Cell Tube Formation In Vitro

  • Kang, Moo-Rim;Lee, Chang-Woo;Yun, Ji-Eun;Oh, Soo-Jin;Park, Song-Kyu;Lee, Ki-Ho;Kim, Hwan-Mook;Han, Sang-Bae;Kim, Hyoung-Chin;Kang, Jong-Soon
    • Toxicological Research
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    • 제28권1호
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    • pp.33-38
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    • 2012
  • In this study, we investigated the effect of methanolic extract isolated from the root of Lycoris aurea (LA) on the growth of cancer cells and the tube formation activity of endothelial cells. Various cancer cells were treated with LA at doses of 0.3, 1, 3, 10 or 30 ${\mu}g/ml$ and LA significantly suppressed the growth of several cancer cell lines, including ACHN, HCT-15, K-562, MCF-7, PC-3 and SK-OV-3, in a dose-dependent manner. We also found that LA induced cell cycle arrest at G2/M phase in ACHN renal cell adenocarcinoma cells. Further study demonstrated that LA concentration-dependently inhibited the tube formation, which is a widely used in vitro model of reorganization stage of angiogenesis, in human umbilical vein endothelial cells. Collectively, these results show that LA inhibits the growth of cancer cells and tube formation of endothelial cells and the growth-inhibitory effect of LA might be mediated, at least in part, by blocking cell cycle progression.

시뮬레이티드 어닐링 알고리즘을 이용한 유연생산시스템의 기계셀-부품군 형성에 관한 연구 (A Study of Formation of Machine Cell-Part Family in FMS using the Simulated Annealing Algorithm)

  • 김진용;박대극;오병완;홍성조;최진영
    • 산업공학
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    • 제10권2호
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    • pp.1-13
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    • 1997
  • The problem of the formation of machine-part cells in FMS is a very important issue at the planning and operating stages of FMS. This problem is inherently a combinatorial optimization problem, proven to be NP-complete(or, NP-hard). Among the several kinds of approaches which have been applied to solve the combinatorial optimization problems, the Simulated Annealing(SA) algorithm, a technique of random search type with a flexibility in generating alternatives, is a powerful problem solving tool. In this paper, the SA algorithm is used to solve machine cell-part family formation problems. The primary purpose of the study is to find the near-optimal solution of machine cell-part family formation problem, whare the product volume and number of operations are prespecified, that can minimize the total material handling cost caused by exceptional elements and intercell moves as much as possible. The results show that the SA algorithm is able to find a near-optimal solution for practical problems of the machine cell-part family formation.

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miR-186 Regulates Glycolysis through Glut1 During the Formation of Cancer-associated Fibroblasts

  • Sun, Pan;Hu, Jun-Wei;Xiong, Wu-Jun;Mi, Jun
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권10호
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    • pp.4245-4250
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    • 2014
  • Emerging evidence has suggested that glycolysis is enhanced in cancer-associated fibroblasts (CAF), and miR-186 is downregulated during the CAF formation. However, it is not clear whether miR-186 is involved in the regulation of glycolysis and what the role of miR-186 plays during the CAF formation. In this study, quantitative PCR analysises show miR-186 is downregulated during the CAF formation. Moreover, miR-186 targets the 3' UTR of Glut1, and its overexpression results in the degradation of Glut1 mRNA, which eventually reduces the level of Glut1 protein. On the other hand, knockdown of miR-186 increased the expression of Glut1. Both time course and dose response experiments also demonstrated that the protein and mRNA levels of Glut1 increase during CAF formation, according to Western blot and quantitative PCR analyses, respectively. Most importantly, besides the regulation on cell cycle progression, miR-186 regulates glucose uptake and lactate production which is mediated by Glut1. These observations suggest that miR-186 plays important roles in glycolysis regulation as well as cell cycle checkpoint activation.

Enhanced Essential Oil Formation by Two-phase Culture of Mentha piperita Cells in Shake Flask and Air-lift Bioreactors

  • Kim, Teresa;Kim, Tae-Yong;Bae, Geun-Won;Chae, Young-Am;Lee, Hyong-Joo;Chung, In-Sik
    • Journal of Microbiology and Biotechnology
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    • 제5권6호
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    • pp.364-369
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    • 1995
  • Effect of two-phase culture on Mentha piperita cell growth and essential oil formation was investigated using shake flask and air-lift bioreactors. LiChroprep RP-B(RP-B) addition did not impair M. piperita cell growth, but resulted in stimulated formation of essential oils and increased ratios of extracellular oil to intracellular oil formation. However, the combined use of RP-B and chitosan elicitor was not synergistic. Volumetric productivity of essential oils in RP-B treated culture using cell-recycled air-lift bioreactor was $6.9\;\mu\textrm{g}/l{\cdot}day$ which was substantially higher than that obtainable from the control. Our results demonstrate the potential of a second phase to enhance overall productivity for M. piperita cell culture.

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고효율 Solar Cell 제조를 위한 Firing 공정 조건의 최적화 (Optimization of the firing process condition for high efficiency solar cells on single-crystalline silicon)

  • 정세원;이성준;홍상진;한승수
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2006년도 추계학술발표회 초록집
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    • pp.4-5
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    • 2006
  • This paper represents modeling and optimization techniques for solar cell process on single-crystalline float zone (FZ) wafers with high efficiency; There were the four significant processes : i)emitter formation by diffusion, anti-reflection-coating (ARC) with silicon nitride using plasma-enhanced chemical vapor deposition (PECVD); iii)screen-printing for front and back metallization; and iv)contact formation by firing. In order to increase the performance of solar cells, the contact formation process is modeled and optimized. This paper utilizes the design of experiments (DOE) in contact formation to reduce process time, fabrication costs. The experiments were designed by using central composite design which is composed of $2^4$ factorial design augmented by 8 axial points with three center points. After contact formation process, the efficiency of the solar cell is modeled using neural networks. This model is used to analyse the characteristics of the process, and to optimize the process condition using genetic algorithms (GA). Finally, find optimal recipe for solar cell efficiency.

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Stress Granules Inhibit Coxsackievirus B3-Mediated Cell Death via Reduction of Mitochondrial Reactive Oxygen Species and Viral Extracellular Release

  • Ji-Ye Park;Ok Sarah Shin
    • Journal of Microbiology and Biotechnology
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    • 제33권5호
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    • pp.582-590
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    • 2023
  • Stress granules (SGs) are cytoplasmic aggregates of RNA-protein complexes that form in response to various cellular stresses and are known to restrict viral access to host translational machinery. However, the underlying molecular mechanisms of SGs during viral infections require further exploration. In this study, we evaluated the effect of SG formation on cellular responses to coxsackievirus B3 (CVB3) infection. Sodium arsenite (AS)-mediated SG formation suppressed cell death induced by tumor necrosis factor-alpha (TNF-a)/cycloheximide (CHX) treatment in HeLa cells, during which G3BP1, an essential SG component, contributed to the modulation of apoptosis pathways. SG formation in response to AS treatment blocked CVB3-mediated cell death, possibly via the reduction of mitochondrial reactive oxygen species. Furthermore, we examined whether AS treatment would affect small extracellular vesicle (sEV) formation and secretion during CVB3 infection and modulate human monocytic cell (THP-1) response. CVB3-enriched sEVs isolated from HeLa cells were able to infect and replicate THP-1 cells without causing cytotoxicity. Interestingly, sEVs from AS-treated HeLa cells inhibited CVB3 replication in THP-1 cells. These findings suggest that SG formation during CVB3 infection modulates cellular response by inhibiting the release of CVB3-enriched sEVs.