• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2003년도 추계학술대회 및 정기총회
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• pp.259-262
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• 2003

Group technology(GT) is a manufacturing philosophy which identifies and exploits the similarity of parts and processes in design and manufacturing. A specific application of GT is cellular manufacturing. the first step in the preliminary stage of cellular manufacturing system design is cell formation, generally known as a machine-part cell formation(MPCF). This paper presents and tests a grouping gentic algorithm(GGA) for solving the MPCF problem and uses the measurements of e(ficacy. GGA's replacement heuristic used similarity coefficients is presented.

• 한국경영과학회지
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• 제23권4호
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• pp.63-73
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• 1998

With the success of flexible manufacturing systems(FMSs), flexible assembly systems(FASs) have been developed to automatic factories further. As in a cellular FMS, a celluar FAS is considered as the most flexible and feasible assembly systems configuration. This paper presents a method for the integrated layout design in cellular FASs. Unlike the traditional paper, this paper deals with the formation of cells and the layout of cells for jobs with operation times on different machines. The procedure in this paper consists of two distinct phases. The first phase presents machine arrangement in a double rows flowline. cell formation not to allow intercellular movements, and integrated layout design in cellular FASs considering the characteristics of FAS, layout, and production factors This phase uses older optimal algorithm. The second phase proposes to balance the system with an objective of reducing the degree of workload deviation in the cells. Simulated annealing method is used to balance the system. This phase also shows the integrated layout design in cellular FASs with the cost less than total cost of the first phase.

• 경영과학
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• 제16권1호
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• pp.157-171
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• 1999

In a increasingly competitive marketplace, the manufacturing companies have no choice but looking for ways to improve productivity to sustain their competitiveness and survive in the industry. Recently cellular manufacturing has been under discussion as an option to be easily implemented without burdensome capital investment. The objective of cellular manufacturing is to realize many aspects of efficiencies associated with mass production in the less repetitive job-shop production systems. The very first step for cellular manufacturing is to group the sets of parts having similar processing requirements into part families, and the equipment needed to process a particular part family into machine cells. The underlying problem to determine the part and machine assignments to each manufacturing cell is called the cell formation. The purpose of this study is to develop a clustering algorithm based on the neural network approach which overcomes the drawbacks of ART1 algorithm for cell formation problems. In this paper, a generalized learning vector quantization(GLVQ) algorithm was devised in order to transform a 0/1 part-machine assignment matrix into the matrix with diagonal blocks in such a way to increase clustering performance. Furthermore, an assignment problem model and a rearrangement procedure has been embedded to increase efficiency. The performance of the proposed algorithm has been evaluated using data sets adopted by prior studies on cell formation. The proposed algorithm dominates almost all the cell formation reported so far, based on the grouping index($\alpha$ = 0.2). Among 27 cell formation problems investigated, the result by the proposed algorithm was superior in 11, equal 15, and inferior only in 1.

• 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.

• 약학회지
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• 제41권4호
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• pp.433-438
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• 1997

MT 51005 as a potent inhibitor of phospholipase C(PLC) was purified from the culture broth of a fungal strain No. 51005 isolated from soil. It was identified as a benzaldehyde d erivative, anguillosporal. by the physico-chemical properties and spectroscopic data. Anguillosporal showed the inhibitory activity against purified PLC with an $IC_{50}\;of\;13{\mu}g/ml$. And it also inhibited the formation of inositol phosphates($IP_t$) in platelet-derived growth factor(PDGF)-stimulated $NIH3T3{\gamma}1$ cells with an $IC_{50}\;of\;0.8{\mu}g/ml$.

• 한국컴퓨터정보학회논문지
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• 제21권4호
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• pp.47-54
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• 2016

Cellular formation and layout problem has been known as a NP-hard problem. Because of the algorithm that can be solved exact solution within polynomial time has been unknown yet. This paper suggests a systematic method to be obtain of 2-degree partial directed path from the frequency of consecutive forward order. We apply the modified Kruskal algorithm of minimum spanning tree to be obtain the partial directed path. the proposed reverse constructive algorithm can be solved for this problem with O(mn) time complexity. This algorithm performs same as best known result of heuristic and metaheuristic methods for 4 experimental data.

• 한국멀티미디어학회논문지
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• 제19권8호
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• pp.1415-1423
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• 2016

Interference in device-to-device (D2D) communication underlaying cellular network needs to be elaborately investigated because of channel sharing. The objective is to improve the quality of D2D communications while maintaining high performance for cellular users. In this paper, we solve the above problem by jointly considering channel allocation and power control using coalition formation game. Our cooperative game theoric approach allows to enhance network-wide performance. We design a merge-and-split algorithm to deal with the complexity of the combinatorial structure in coalition formation problem. The analytical and numerical results show that our algorithm converges to a stable point which achieves high network performance.

• 한국미생물·생명공학회지
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• 제25권6호
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• pp.592-597
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• 1997

During the screening of inhibitors against phospholipase C (PLC) and the formation of inositol phosphates (IP$_{t}$) at NIH3T3${\gamma}$1 cells from microbial secondary metabolites, we selected a fungal strain MT60109 which was capable of producing an inhibitor. By the taxonomic studies, this fungus was identified as Pseudallescheria sp. MT60109 and an inhibitor of PLC was purified by BuOH extraction and chromatographic techniques from the culture broth of Pseudallescheria sp. MT60109. The inhibitor was identified as thielavin B by the physico-chemical properties and spectroscopic analysis of UV, FAB-MS, $^{1}$H, $^{13}$C-NMR, $^{1}$H-$^{1}$H COSY and HMBC. Thielavin B showed potent inhibitory activity against PLC purified from bovine brain with an IC$_{50}$ of 20 $\mu$M. And it also inhibited the formation of inositol phosphates in platelet-derived growth factor (PDGF) -stimulated NIH3T3${\gamma}$1 cells with an IC$_{50}$ of 20 $\mu$M.

• Animal cells and systems
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• 제12권1호
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• pp.1-9
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• 2008

In the developing limb, chondrogenesis is an important prerequisite for the formation of cartilage whose template is required for bone formation. Chondrogenesis is a tightly regulated multi-step process, including mesenchymal cell recruitment/migration, prechondrogenic condensation of the mesenchymal cells, commitment to the chondrogenic lineage, and differentiation into chondrocytes. This process is controlled exquisitely by cellular interactions with the surrounding matrix and regulating factors that initiate or suppress cellular signaling pathways and transcription of specific genes in a temporal-spatial manner. Understanding the cellular and molecular mechanisms of chondrogenesis is important not only in the context of establishing basic principle of developmental biology but also in providing research direction toward preventive and/or regenerative medicine. Here, I will overview the current understanding of cellular and molecular mechanisms contributing to prechondrogenic condensation processes, the crucial steps for chondrogenesis, focusing on cell-cell and cell-matrix interactions.

• Molecules and Cells
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• 제39권6호
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• pp.484-494
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• 2016

Plant cells have a remarkable ability to induce pluripotent cell masses and regenerate whole plant organs under the appropriate culture conditions. Although the in vitro regeneration system is widely applied to manipulate agronomic traits, an understanding of the molecular mechanisms underlying callus formation is starting to emerge. Here, we performed genome-wide transcriptome profiling of wild-type leaves and leaf explant-derived calli for comparison and identified 10,405 differentially expressed genes (> two-fold change). In addition to the well-defined signaling pathways involved in callus formation, we uncovered additional biological processes that may contribute to robust cellular dedifferentiation. Particular emphasis is placed on molecular components involved in leaf development, circadian clock, stress and hormone signaling, carbohydrate metabolism, and chromatin organization. Genetic and pharmacological analyses further supported that homeostasis of clock activity and stress signaling is crucial for proper callus induction. In addition, gibberellic acid (GA) and brassinosteroid (BR) signaling also participates in intricate cellular reprogramming. Collectively, our findings indicate that multiple signaling pathways are intertwined to allow reversible transition of cellular differentiation and dedifferentiation.