• 한국식품과학회지
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• 제35권5호
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• pp.884-892
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• 2003

균질화 속도와 시간, 그리고 온도, 물 첨가량에 따른 감귤과피 물균질액의 제조공정시 최적조건을 찾기 위하여 물균질액의 추출효율지수를 나타내는 EI와 감귤과피 물균질액으로 코팅한 유색미의 색도를 나타내는 b value를 변수로 하여 최적화를 시도하였다. 감귤과피를 이용한 물균질액 제조시 EI는 추출온도를 제외한 균질화 속도와 시간, 물 첨가량에 크게 영향을 받았다. 수립된 회귀식에 대한 적합성 결여 분석결과 EI, b value에 대해 유의성이 없어 반응표면 모형이 통계적으로 유의하였다. 최적조건을 선정하기 위하여 비교적 영향이 적은 것으로 판단되는 균질화 시간과 온도를 중심점으로 고정하고 제한 변수를 최대로 하는(EI을 400이상, b value를 24이상) 물균질액 제조의 최적조건은 물 첨가량 42mL, 균질화 속도 8,500rpm이었다. 다음으로 첨가량과 균질화 속도를 이 조건으로 고정하고서 EI을 400이상, b value를 24이상으로 하는 감귤과피 물균질액의 제조조건으로는 물의 온도는 $53^{\circ}C$ 및 균질화 시간은 2.8분으로 결정할 수 있었다.

• 품질경영학회지
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• 제46권3호
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• pp.739-752
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• 2018

Purpose: The purpose of this study was to investigate the relationship between kiln processing parameters and NOx emissions that occur in the sintering and calcination steps of the cement manufacturing process and to derive the main factors responsible for producing emissions outside emission limit criteria, as determined by category models and classification rules, using data mining techniques. The results from this study are expected to be useful as guidelines for NOx emission control standards. Methods: Data were collected from Precalciner Kiln No.3 used in one of the domestic cement plants in Korea. Thirty-four independent variables affecting NOx generation and dependent variables that exceeded or were below the NOx emiision limit (>1 and <0, respectively) were examined during kiln processing. These data were used to construct a detection model of NOx emission, in which emissions exceeded or were below the set limits. The model was validated using SPSS MODELER 18.0, artificial neural network, decision treee (C5.0), and logistic regression analysis data mining techniques. Results: The decision tree (C5.0) algorithm best represented NOx emission behavior and was used to identify 10 processing variables that resulted in NOx emissions outside limit criteria. Conclusion: The results of this study indicate that the decision tree (C5.0) can be applied for real-time monitoring and management of NOx emissions during the cement firing process to satisfy NOx emission control standards and to provide for a more eco-friendly cement product.

• 스마트미디어저널
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• 제9권3호
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• pp.31-40
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• 2020

현재 제조 분야 빅데이터 분석을 위하여 black-box 기반 기계 학습 알고리즘을 활용하고 있다. 해당 알고리즘은 높은 분석 정합성 가지는 장점이 있지만, 분석 결과에 대한 해석이 어렵다는 단점이 있다. 그러나 제조업에서는 분석 알고리즘은 제조 공정 원리 기반 해석을 통하여 결과의 근거 및 도출 타당성에 대한 검증이 중요하다. 이러한 기계 학습 알고리즘의 결과 설명력 한계를 극복하기 위하여 유전 프로그래밍을 활용한 제조 빅데이터 분석 방법을 제안한다. 본 알고리즘은 생물학적 진화유전 프로그래밍 알고리즘은 생물학적 진화를 모방한 진화 연산 (선택, 교배, 돌연변이) 반복하면서 최적의 해를 찾아간다. 그리고 해는 수학적 기호를 활용하여 변수 간의 관계로 나타나며, 가장 높은 설명력을 가지는 해가 최종적으로 선택된다. 이를 통하여 입력 및 출력 변수 관계 수식화를 통한 결과를 도출하므로 직관적인 제조 매카니즘에 대한 해석이 가능하며 또한 수식으로 나타낸 변수간의 관계 기반으로 기존 해석이 불가한 제조 원리 도출도 가능하다. 제안 기법은 대표적인 기계 학습 알고리즘과 성능을 비교 분석 결과 동등 또는 우수한 성능을 보였다. 향후 해당 기법을 통하여 다양한 제조 분야 활용 가능성을 검증하였다.

• Transactions on Electrical and Electronic Materials
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• 제12권3호
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• pp.115-118
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• 2011

Process characterization of the chemical mechanical polishing (CMP) process for undensified phosphosilicate glass (PSG) film is reported using design of experiments (DOE). DOE has been addressed to experimenters to understand the relationship between input variables and responses of interest in a simple and efficient way. It is typically beneficial for determining the adequate size of experiments with multiple process variables and making statistical inferences for the responses of interests. Equipment controllable parameters to operate the machine include the down force (DF) of the wafer carrier, pressure on the backside of the wafer, table and spindle speed (SS), slurry flow rate, and pad condition. None of them is independent; thus, the interaction between parameters also needs to be indicated to improve process characterization in CMP. In this paper, we have selected the five controllable equipment parameters, such as DF, back pressure (BP), table speed (TS), SS, and slurry flow (SF), most process engineers recommend to characterize the CMP process with respect to material removal rate (RR) and film uniformity as a percentage. The polished material is undensified PSG. PSG is widely used for the plananization in multi-layered metal interconnects. We identify the main effect of DF, BP, and TS on both RR and film uniformity, as expected, by the statistical modeling and analysis on the metrology data acquired from a series of $2^{5-1}$ fractional factorial design with two center points. This revealed the film uniformity of the polished PSG film contains two and three-way interactions. Therefore, one can easily infer that the process control based on better understanding of the process is the key to success in semiconductor manufacturing, typically when the wafer size reaches 300 mm and is continuously scheduled to expand up to 450 mm in or little after 2012.

• 한국생산제조학회지
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• 제6권3호
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• pp.26-35
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• 1997

In this study, the drawing characteristics of circular drawbead are examined with the plane strain elastic-plastic FE Method. Both the clamping load and the drawing load investigated by varying the process variables such as drawbead radius, closing depth and friction condition. The effective strain induced by the draw bead is also investigated. In order to verify the results, the computed results are compared with the existing experimental results. It has been found that both the clamping load and drawing loads are related with the geometry of the bead rather than the lubrication conditions.

• 품질경영학회지
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• 제7권2호
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• pp.22-28
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• 1979

The problem considered in this paper is to select the vital factor effect to the product quality through the experimental design and analysis of response surface, so as to control the quality improvement of industrial product. In this time, even through the mathematical model is unknown it could be applicable to control the quality of industrial products and to determine optimum operating condition for many technical fields, particulary, for industrial manufacturing process. When a set of data is available from an experimental design, it is often of interest 1:0 fit polynominal repression model in independent variables (eg, time, temperature, pressure, etc) the optimize the response variable (eg. yield, strength etc). This paper proposes a method known to obtain the optimum operating condition, and how to find the condition by using table of orthogonal array experiments, and optimization methodology of statistical model. A criterion can be applied determining to optimum operating conditions in manufacturing industry and improving the fit of response surface which may be used for prediction of responses and quality control of industrial products.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.422-427
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• 2000

Gear design carried in former type determined a few variables like module, pressure angle, helix angle. After investigating repeatedly results obtained through stress analysis and making a determination an optimal shape, but its design process was not only complex but also difficult to get a precise profile curve from operating by hand. In this study, rotating shape of gear profile curves were generated automatically with standard spur gear, equivalent helical gear, shifted gear & pinion by using developed program which is Auto_LISP language supported in Auto-CAD. Output tooth profile by using CAE program is applied as Preprocessor for stress analysis in each contact points. This program which can be determined rapidly an optimal shape of gear will be successfully supported for Small & Medium companies designing and manufacturing gears by using Auto-CAD.

• 한국생산제조학회지
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• 제18권4호
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• pp.430-435
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• 2009

The cooling stage greatly affects the product quality in the injection molding process. The cooling system that minimizes temperature variance in the product surface will improve the quality and the productivity of products. The cooling circuit optimization problem that was once solved by a response surface method with 4 design variables. It took too much time for the optimization as an industrial design tool. It is desirable to reduce the optimization time. Therefore, we tried the back-propagation algorithm of artificial neural network(BPN) to find an optimum solution in the cooling circuit design in this research. We tried various ways to select training points for the BPN. The same optimum solution was obtained by applying the BPN with reduced number of training points by the fractional factorial design.

• 한국생산제조학회지
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• 제18권4호
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• pp.355-361
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• 2009

In this paper, an analysis technique is presented for performing the effective design of bus structure. Sensitivity analysis is carried out for the natural frequency of component structures consisting of bus B.I.W. Local vibration modes of substructure, which large affect on the global vibration mode of the bus B.I.W., are obtained through the sensitivity analysis technique using the mathematical chain rule. And also the design variables, which are determined from the sensitivity analysis, are redesigned through optimum design process. The proposed analysis technique shows that the bus structure can be effectively designed considering the vibration characteristics.

• 산업공학
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• 제16권spc호
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• pp.39-44
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• 2003

As one of many design variables, the role of dimension tolerances is to restrict the amount of size variation in a manufactured feature while ensuring functionality. In this study, a nonlinear integer model has been modeled to allocate the optimal tolerance to each individual feature at a minimum manufacturing cost. While a normal distribution determines statistically worst tolerances with its symmetrical property in many previous tolerance allocation studies, a asymmetrical distribution is more realistic because its mean is not always coincident with a process center. A nonlinear integer model is modeled to allocate the optimal tolerance to a feature based on a beta distribution at a minimum total cost. The total cost as a function of tolerances is defined by machining cost and quality loss. After the convexity of manufacturing cost is checked by the Hessian matrix, the model is solved by the Complex Method. Finally, a numerical example is presented demonstrating successful model implementation for a nonlinear design case.