• Proceedings of the Korea Society for Simulation Conference
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• 2000.11a
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• pp.165-173
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• 2000

Analytic models have been developed to solve integrated production-distribution problems in supply chain management (SCM). As one of major constraints in analytic models, capacity, which is the total operation time in this paper has mostly been known or disregarded assuming infinite capacity. Also, as major factors, machine processing time to fabricate or assemble a part or product at a certain machine center in production system and vehicle processing time to deliver a product to a customer by a certain vehicle in distribution system have been fixed and regarded as a static factor, But in the real systems significant differences exit between capacity and the required time to achieve the production-distribution plan and between processing time and consumed time to process a part or product. In this paper, capacity and processing times in the analytic model are considered as dynamic factors and adjusted by the results from independently developed simulation model, which includes general production-distribution characteristics. Through experiments, we obtain the more realistic solutions reflecting stochastic natures by performing the iterative analytic-simulation procedure.

• Applied Biological Chemistry
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• v.16 no.2
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• pp.94-98
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• 1973

1. Tomato variety used was Bogsu No. 2 and it was grown in field. Experiments were conducted in 1971 and 1972 to examine the changes of $CO_2$ product on in each growth-period and the contents of acid, sugar and vitamine C during storage. 2. By controlled atmospheric pressure the effects of respirationreduction in tomato fruits were the most effective at 660 Torr. part. 3. $CO_2$ production of tomato fruits harvested at each growth-period was differently changed at each growth-period and $CO_2$ production in tomato fruit at the same maturity from the plant showed Sigmoid type. 4. $CO_2$ production of tomato fruits harvested at the same ripeness score was in influenced by controlled atmospheric pressure during growth period and $CO_2$ production was reduced at SAP part compared with NAP part during the full growth-period. 5. The change of weight in tomato fruits was decreased in NAP part than in SAP part during storage and contents of acid, sugar, and vitamine C showed the same tendency.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.04a
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• pp.151-156
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• 2000

Ultra precision progressive die have used for above one million's lot size of production part. In the field of design and making tool for press working, the progressive die for sheet metal (STS 304, thickness : 0.5mm) is a specific division. In order to prevent the defects, the optimum design of the production part, strip layout, die design, die making and tryout etc. are necessary. They require analysis of many kinds of important factors, i.e. theory and practice of metal press working and its phenomena, die structure, machining condition for die making, die materials, heat treatment of die component, know-how and so on. In this study, we designed and constructed a progressive die of multi-stage and performed try out. Out of these processes the die development could be taken for advance. Especially the result of tryout and its analysis become the characteristics of this paper (part 1 and part 2) that nothing might be ever seen before such as this type of research method on all the processes. In the part 2 of this study we treated die making and tryout mostly.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.589-594
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• 1991

Group Technology (GT) is a technique for identifying and bringing together related or similar components in a production process in order to take advantage of their similarities by making use of, for example, the inherent economies of flow production methods. The process of identification, from large variety and total of components, of the part families requiring similar manufacturing operations and forming the associated groups of machines is referred as 'machine-component grouping'. First part of this paper is devoted to describing a hierarchical divisive algorithm based on graph theory to find the natural part families. The objective is to form components into part families such that the degree of inter-relations is high among components within the same part family and low between components of different part families. Second part of this paper focuses on establishing cell design procedures. The aim is to create cells in which the most expensive and important machines-called key machine - have a reasonably high utilization and the machines should be allocated to minimize the intercell movement of machine loads. To fulfil the above objectives, 0-1 integer programming model is developed and the solution procedures are found. Next an attempt is made to test the feasibility of the proposed method. Several different problems appearing in the literature are chosen and the results air briefly showed.

• International Journal of CAD/CAM
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• v.6 no.1
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• pp.51-58
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• 2006

In rapid prototyping, the optimal part orientation during fabrication is critical as it can improve part accuracy, minimize the requirement for supports and reduce the production time. Through investigating the geometric issues of STL model and process planning of RPM, This paper establishes optimizing model based on the considerations of staircase effect, support area and production time. The general satisfactory degree function is constructed employing the multi-objective optimization theory based on the general satisfactory degree principle. The best part-building orientation is obtained by solving the function employing generic algorithm. Experiment shows that the methods can effective resolve the part-building orientation in RP.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.1
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• pp.65-72
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• 2002

Generally, there are laser operating equipments( aligner, stepper) and electronic microscope( SEM, TEM) as a high precision manufacturing and inspection equipment in semiconductor production companies, precision examination and measuring laboratories. Mostly, these equipments are characterized by projection and target part. The relative displacements between projection and target part are dominant roles in vibrational problem in these precision equipments. These relative displacements are determined by the position of incoming vibration and the difference of vibration response in projection and target part. In this study, the allowable vibrational limits are suggested and the vibrational reduction plans are proposed by measurement and analysis of vibration phenomenon in the Clean Room in PDP(plasma display panel) production building. The vibration performance is evaluated by comparison relative displacements between projection and target part before/after the vibration isolation plan.

• Korean Journal of Organic Agriculture
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• v.17 no.1
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• pp.1-17
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• 2009

The production of bio-energy crops is a major research project in the emphasizing the "low carbon green growth" strategy. For this, the possibility of the introduction of the new energy crops improve the agricultural income from fanning must be diagnosed. This study describes the level of agricultural income per unit area by cropping system based on the income of crops in the field. Especially, we have chosen the southern part attracting the attention in the possible area of the bio-energy crop production. This study consists of five chapters. Chapter I is the introduction. Chapter II is on the status of the southern part cropping system and the analysis of the economic value. Chapter III is on the economic value analysis introducing new bio-energy crops. Chapter IV is on the comparative analysis for the economic value of the croping system introducing new bio-energy crops. Chapter V is the conclusion.

• Korean Journal of Computational Design and Engineering
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• v.16 no.1
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• pp.41-51
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• 2011

Both enterprise information systems and CAD utilizes the BOM (Bill of Material) as the means of collaborative integration during the product design and production since the BOM has been commonly used for design, production planning, procurement, and production works. Therefore, BOM can be the referential data when it expresses not only the part lists but also product information required by product development process. Outfitting design is one of major design works in marine vessel design since marine vessels have various outfitting systems and huge number of parts. Also, the outfitting BOM has the evolutional forms that change from the initial design to the production design. In order to express the product information and part list in the enterprise BOM and the evolutional BOMs in each lifecycle, enterprise BOM of outfitting that consists of structure BOM and display BOM is suggested. Thereafter, we have developed the prototype of enterprise BOM in which some features of the outfitting BOM are implemented.

• International Journal of Quality Innovation
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• v.4 no.1
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• pp.148-159
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• 2003

Variation is the archenemy of quality. To reduce or control the variation in a complex production unit, firstly we need to identify the location of the root cause of the variation. This paper discusses the detection of variability and the techniques used for reduction of variation for a production unit consisting of many processes. In the first part of this paper, the background of variability detection in production systems is introduced which is then followed by a weighted network corresponding to correlation matrix of all processes. Based on the network and clustering criterion of maximum spanning tree, a classification of all processes is derived. Furthermore, the variation of each process in a class is determined by residual analysis. In the last part, the use of methods of robust design for the processes with a larger variability is discussed.

• Ocean and Polar Research
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• v.34 no.2
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• pp.229-237
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• 2012

Using results from an Earth System model, we investigated change in primary production in the East China Sea, under a global warming scenario. As global warming progresses, the vertical stratification of water becomes stronger, and nutrient supply from the lower part to the upper part is reduced. Consequently, so is the primary production. In addition to the warming trend, there is strong decadal to interdecadal scale variability, and it takes a few decades before the warming trend surpasses natural variability. Thus, it would be very hard to investigate the global warming trend using data of several years' length.