• 품질경영학회지
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• 제50권1호
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• pp.153-167
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• 2022

Purpose: The purpose of this study is to guide the operation managers who plan daily production of large mass-processing facility that services multi-customers with multi-product, small-batch item characteristics by providing the practical best production quantity and the inventory allowed to build. Methods: Close observation of a subcontract paint-shop operator captured the daily decision process which was reflected in the subcontractor-unique mathematical model and the system dynamics simulation model. Multiple simulations were run to find the practical best production quantity and the maximum allowable stock level of inventory that did not undermine the profit from practical best daily production. Actual data and a few constant values were obtained from the firm under study. Results: While the inventory holding cost for the customer-owned material harms the total profit of the subcontractor, the running cost of the processing facility hinders production in small batches. This balances the maximum possible productions and results in practical best daily production which can be found through simulation runs with actual data. The maximum level of stocked inventory is deduced from the practical best daily production. Conclusion: To build a large volume that enables economy-of-scale production, operators should deal with multi-product small-batch items from multiple customers. When the planned schedule of the time and amount of material in-flow tend not to be reliable, operators can find it practical to execute level production across the planning horizon instead of adjusting to day-to-day in-flow fluctuations.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 추계학술대회
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• pp.210-212
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• 2022

제조업에서 생산 설비의 상태를 모니터링하기 위해 각종 센서를 부착하고 있으며, 이를 통해 획득된 데이터의 경우 시계열 데이터인 경우가 많다. 생산 설비의 이상 여부를 판단하기 위해서는시계열 데이터로부터 패턴을 추출하는 과정이 선행되어야 하며 다양한 방법이 연구되고 있다. 본 논문에서는 수집된 다변량 시계열 데이터로부터 패턴을 추출하기 위해 매트릭스 프로파일 알고리즘을 적용하였으며, 이를 통해 현재 CNC 머신으로부터 수집 중인 다중 센서 데이터의 패턴을 추출하였다.

• 기술혁신연구
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• 제6권1호
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• pp.187-214
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• 1998

This paper tries to examine the effectiveness of inventory reduction to the productivity increase and the impact of production environments on its effectiveness utilizing the Profit Impact of Market Strategy (PIMS) Database from the Strategic Planning Institute, a large data set that covers a variety of manufacturing activities from the early 1970s to late 1980s. The empirical results of this paper support the robustness of the principle of "Lean Production" or JIT system (also referred to as "Stockless Production"). We also find that the overall environment in which manufacturing strategic business units operate is an important factor in determining the different degrees of effectiveness of the work-in process (and raw materials) invertory reductions. In particular, we find that the effectiveness of the work-in process reduction varies according to the position in the product life cycly as well as the complexity and characteristics of the production processes.roduction processes.

• Journal of information and communication convergence engineering
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• 제18권3호
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• pp.167-175
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• 2020

The net income per unit area from crop production could be the most critical consideration for agricultural producers during cultivation planning. This paper proposes a scheme for predicting the net income per unit area based on machine learning and related calculations. This scheme predicts rice production and operation costs by applying climate and price index data. The rice price is also predicted by applying rice production and operation cost data. Finally, these predicted results are employed to calculate the predicted net income, which is compared with the actual net income. Consequently, the proposed scheme shows a meaningful degree of conformity, which indicates the potential of machine learning for predicting various aspects of agricultural production.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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• pp.683-690
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• 2003

This purpose of this research is an attempt to measure and comparatively analyze the efficiencies and RTS(Returns to Scale) using panel data of OECD countries including Korea. In order to achieve this purpose, at first this study used efficient production frontier estimation combined with DEA for obtaining parameter estimates of a efficient production frontier. secondly using estimated results, measured R&D productivity and RTS(Returns to Scale) on all of the OECD countries. thirdly using time-series data related to R&D activity of korea, measured R&D productivity and RTS(Returns to Scale). Finally based on the results of R&D productivity and RTS(Returns to Scale) using efficient production frontier, some policy implications for enhancing the R&D competitiveness and the technological capabilities are discussed.

• Ocean and Polar Research
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• 제34권2호
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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.

• 복식
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• 제51권1호
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• pp.75-85
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• 2001

The purpose of this study is to provide for the basic data useful to the high quality knitwear production. For this purpose, knit promotions that product knitwear for 20 age ∼ 30 middle age women were sampled to survey the fabric planning and production·quality management of knitwear, and their directors were surveyed through direct interviews. Data is processed by a computer(SPSS) and analyzed by using frequency, percentage, mean. The results of this study are as fellows. 1. Most of the sample companies were getting smaller or pettier in terms of capital, number of employees. 2. Knit promotions were universally using acrid and wool as knit fabric. 3. Knitwear tended to be producted much in knit promotions. 4. It is needed to use high quality fabric and perform careful sewing for knitwear quality rising.

• International Journal of Precision Engineering and Manufacturing
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• 제6권2호
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• pp.40-45
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• 2005

This paper has presented an application of an optimum grinding conditions based on the fuzzy logic. Fuzzy logic can handle vague and uncertain knowledge, and presents a scheme for integrating data with various kinds of grinding data. Especially, this research is capable of determining the grinding conditions taking into account some fuzzy membership function represented for trapezoidal form such as hardness and surface roughness of workpiece, material tensile strength and elongation, and requirement of grinding method. Larsen's fuzzy production method utilizing the fuzzy production rule can be applied on the establishment of grinding conditions, and also the output value obtained by the center of gravity method can effectively utilize the optimum grinding conditions.

• Korean Journal of Geomatics
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• 제3권2호
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• pp.107-114
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• 2004

The National Geographic Information Institute (NGII) in korea, through the National Geographic Information System (NGIS) Program, has prepared to generate and disseminate digital elevation data for Korea. This is a pilot research to propose a policy for production, maintenance, and supply of Korea Digital Elevation Data(KDED). Customer demands for accuracy and resolution of DEM was surveyed through a questionnaire. In order to investigate the quality, the technical efficiency and the production cost, a tentative DEM in a small test site was generated based on digital topographic maps (original paper map scale 1:5,000), analytical plotter, and LIDAR. The Accuracy standard for KDED was derived based on source data generation methods. As a result of this research, a uniformly spaced grid model was recommended for KDED. Its preferable grid space is 5m in urban areas and its vicinity, and 10m in field and mountainous area. LIDAR has been valuated as a proper KDED generation method fulfilling customers' demands for the accuracy.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
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• pp.300-305
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• 2008

Using WindPRO that was software for windfarm design developed by EMD from Denmark, wind resources for the western Jeju island were analyzed, and the performance of WindPRO prediction was evaluated in detail. The Hansu site and the Yongdang site that were located in coastal region were selected, and wind data for one year at the two sites were analyzed using WindPRO. As a result, the relative error of the Prediction for annual energy Production and capacity factor was about ${\pm}20%$. For evaluating wind energy more accurately, it is necessary to obtain lots of wind data and real electric power production data from real windfarm.