• 한국기계기술학회지
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• 제20권6호
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• pp.745-750
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• 2018

In this study, the thermal behavior of adaptor housing was analyzed by the numerical method. The boundary conditions used to die casting process were the temperature of molten metal and injection time. As the temperature of the molten metal increased, the tensile strength of the product decreased by the blow hole generated in the molten metal, and the decreasing tendency was gradually decreased. As the injection time of the molten metal increased, the heat flux rose, but the degree of the increase was very small. So, the injection time of the molten metal had little effect on the thermal behavior and diffusion of the adapter housing. As a result, the heat of the molten metal was transferred into the housing and the thermal behavior spread widely.

• Design & Manufacturing
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• 제18권2호
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• pp.64-73
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• 2024

The purpose of this paper is to introduce a fusion method that combines the design of experiments (DOE) and machine learning to optimize the bias of plastic products. The study focuses on the plastic motor housing used in automobiles, which is manufactured through plastic injection molding. Achieving optimal molding for the motor housing involves the optimization of various molding conditions, including injection pressure, injection time, holding pressure, mold temperature, and cooling time. Failure to optimize these conditions can lead to increased product deformation. To minimize the deformation of the motor housing, the widely used Taguchi method, which is one of the design of experiment techniques, was employed to identify the injection molding conditions that affect deformation. Machine learning was then applied to various models based on the identified molding conditions. Among the models, the Random Forest model emerged as the most effective in predicting deformation amounts. The validity of the Random Forest model was also confirmed through verification. The verification results demonstrated the excellent prediction accuracy of the trained Random Forest model. By utilizing the validated model, molding conditions that minimize deformation were determined. Implementation of these optimal molding conditions led to a reduction of approximately 5.3% in deformation compared to the conditions before optimization. It is noteworthy that all injection molding outcomes presented in this paper were obtained through robust injection molding simulations, ensuring both research objectivity and speed.

• 토지주택연구
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• 제3권2호
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• pp.187-193
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• 2012

최근 에너지 관련 연구분야에서 새롭게 주목받는 것이 주변의 에너지를 수확하는 에너지 하비스팅 기술이다. 본 논문에서는 다양한 에너지 하비스팅 기술들 중 압전 기술과 전자기 유도 방식을 조합한 에너지 블록의 발전성능이 조사되었다. 본 연구의 목적은 개발된 에너지 하비스팅 블록의 주택 도시 분야 적용성을 평가하기 위한 것이다. 이를 위해 본 논문에서는 실험실 규모의 다층 에너지 하비스터의 현 발전수준을 평가하여 제시하였다. 그 다음으로 증폭기술이 적용된 프로토타입의 특징을 설명하고 개발된 프로토타입 모듈의 발전성능을 다각적으로 평가하여 제시하였다. 성능 평가 결과, 개발된 에너지 블록은 기존 상용 제품에 비해서 255%와 505%까지 성능이 향상되었고 그 우수성이 입증되었다. 마지막으로 에너지 하비스팅 블록의 후속 연구 방향을 제시하였다.

• Design & Manufacturing
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• 제8권1호
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• pp.35-39
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• 2014

Window roller housings are durable because high-quality source materials such as stainless steel is used in making them. After a series of precise structure analysis, their design is optimized. They are subject to repetitive driving tests of more 100,000 times, durability tests, impact resistance tests, corrosion tests and others. For a long time, gaps often occur in press molded products owing to serious squareness deformation and flatness deformation of them. Severe burrs in press molded products require frequent grinding, which leads to short life cycle and rough or unreliable movement of assembled roller housing, which, in turn, causes product defects. This study focuses on developing measures to resolve existing defects and to improve lifespan of dies by designing and making a window roller shearing die.

• 소성∙가공
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• 제5권3호
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• pp.219-231
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• 1996

The current five-stage cold extrusion process to produce an axle-housing is investigated for the purpose of improved process. The main goal of this study is to obtain an appropriate reduced process sequence which can produce the required part most economically without tensile crack-ing workpiece buckling and overloading of the tools. The current process sequence is simulated and design criteria are examined. during the simulation several remeshings are done due to severe mesh distortions, Based on the results of simulations of the current five-stage process, design strategy for improving the process sequence are developed using the thick hollow pipes. The finished product of an axle-housing is produced in two operations and one annealing treatment while the conventional sequence consists of five operations and one annealing treat-ment. Also die loads of the new process are compared with those of the current one.

• 소성∙가공
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• 제24권5호
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• pp.332-339
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• 2015

In the current paper, a cold forging sequence was developed to manufacture a precisely cold forged H/Lower, which is used as the air back unit in commercial automobiles. The preform shape of the H/Lower influences the dimensional accuracy and stiffness of the final product. The shape factor (SF) ratio and shape of the tools are considered as the design parameters to achieve adequate backward extrusion height and maintain appropriate thickness variations. The optimal conditions of the design parameters were determined by using an artificial neural network (ANN). To experimentally verify the optimal preform and tool shapes, the experiments of the backward extrusion of the H/Lower were executed. The process design methodology proposed in the current paper, can provide a more systematic and economically feasible means for designing the preform and tool shapes for cold forging.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1995년도 추계학술대회논문집
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• pp.48-56
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• 1995

A manufacturing process for the axle-housing is analyzed by the rigid-plastic finite element method. The process contains five stages for the final product. During the simulation, remeshings are done four times due to severe mesh distributions. FE Analysis is performed mainly for strain distributions and load-stroke relationships. Those results are to be an useful design criteria for designing a new process sequence in future.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.603-606
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• 2007

2007년 현재 우리나라의 아파트 시장은 건설업체의 이름보다 브랜드가 더 알려져 있는 것이 현실이다. 이런 아파트의 브랜드화는 10년 전으로 거슬러 올라간 외환위기 이 후부터 존재하기 시작하였다. 외환위기 이 후 분양가 자율화와 주택시장의 구조변화로 인해 건설업체간의 경쟁은 브랜드 아파트라는 새로운 개념을 창출 해 냈고, 현재 브랜드가 분양시장에 있어서는 매우 큰 영향력을 발휘하고 있는 것은 누구나 다 알고 있는 사실이 되어버렸다. 이와 같이 브랜드가 건설업체의 중요한 요소로 두각 되고 있음에도 불구하고, 브랜드 아파트를 형성하고 있는 여러 요인들과 그것의 실제 사용자인 거주자에 관한 상관관계에 대한 연구는 거의 이루어지지 않고 단편적인 측면의 브랜드 전략과 거주자의 만족도에 대한 연구만이 진행되어 왔다. 이에 본 연구는 아파트 브랜드와 주거의 상관관계의 영향변수를 분류하여 이들 간의 상호작용을 시스템 사고 이론에 입각하여 연결하고, 그 구조를 동태적으로 파악하여 상관관계가 어떻게 이루어지고 있음을 보이고, 나아가서 아파트 브랜드에 대한 건설업체의 전략수립의 기초정보를 제공하고자 한다.

• 대한가정학회지
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• 제35권3호
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• pp.287-305
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• 1997

The purpose of this study was to analyze a causal effect on the housewife's leisure activity participation, leisure expenditure and leisure life satisfaction. Data was collected 249 housewives in Pusan. Data were analysed using descriptive statistics, one-way Anova, multiple regression, Pearson's correlation and path analysis. The main findings of the research were as follows: First, there were significant differences in leisure activity participation according to socio-demographic and economic variables. Physical type showed significant differences when housewife was 30's and unemployed, size of family was 3 and 4, age of the lastborn child was under 6, occupation of husband was professionals and technicians, educational attainment of housewife was under highschool graduate, pattern of housing was collective, income was higher. There were significant differences that occupation of husband was professionals and technicians, educational attainment of housewife was over junior college graduate, pattern of housing was collective, income was higher in self-developing type. restful type showed significant differences when housewife was 40's, age of the lastborn child was under 13-18, educational attainment of housewife was under highschool graduate. There were significant differences that housewife was unemployed in home-oriented type. There were significant differences that housewife was 30's and unemployed, size of family was 4, age of the lastborn child was under 6, occupation of husband was market and sales worker, educational attainment of housewife was over junior college graduate, pattern of housing was collective in time-spending type. Second, there were significant differences in leisure time, leisure expenditure and leisure life satisfaction according to socio-demographic and economic variables. Leisure time showed significant differences when housewife was unemployed, age of the lastborn child was under 13-18, occupation of husband was service, educational attainment of housewife was under highschool graduate, income was higher. Leisure expenditure showed significant differences when housewife was 30's, size of family was under 3, age of the lastborn child was under 6, occupation of husband was senior officials and manager, educational attainment of housewife was over junior college graduate, pattern of housing was collective, income was over 5,000,000 won. There were significant differences that housewife was unemployed in leisure life satisfaction. Third, casual effect was path analysed according to path model. Employment and unemployment of housewife, income and occupation of husband (product & transport equipment operator) had an effect on phycial type. Age of housewife, employment and unemployment of housewife and occupation of husband (product & transport equipment operator) had an effect on children-concerned type. Age of housewife had an effect on social-concerned type. Education of husband, income, age of lastborn child and occupation of husband (professor and teacher) had an effect on self-developing type. Age of lastborn child, employment and unemployment of housewife and occupation of husband(product & transport equipment operator) had an effect on children-concerned type. Age of lastborn child and children number had an effect on religious-social type. Employment and unemployment of housewife had an effect on home-oriented type. Age of housewife, education of husband had an effect on time-spending type. Restful type, employment and unemployment of housewife, and occupation of husband(service) have an effect on leisure time. Income, leisure time, self-developing type, children concerned type and occupation of husband(senior officials and manager) had an effect on leisure expenditure. Leisure expenditure, self-developing type, employment and nemploymentof housewife, income had an effect on leisure life satisfaction.

• 한국식품조리과학회지
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• 제18권2호
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• pp.247-261
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• 2002

This study was designed to identify the purchasing practice on the bakery products by the female university students in Seoul and Kyunggi area. Total 262 questionnaires were used for the analysis among 285 responses. The results showed that 50.76% of the respondents bought the bakery products 1∼3 times a month mainly for supper or snacks. The most favored bakery products were bread, danguaja bbang, cake, pie and jori bbang, and there was a signigicant difference in the preference of bakery products by the type of dwelling (p<0.001). Students with non-food science major significantly preferred bakeries as light meals (p＜0.01). Students with food science major liked bread, jori bbang, cake and pie, but the non-food science majors liked bread, sweat red-bean bread and sandwich (p＜0.05). Depending upon the housing status and the major of the respondents, there was a signifcant difference in the purchase factor like nutrition, taste, size and sanitation of the store (p<0.05), while the purchasing frequency was not affected by those factors (p＜0.05). As to the question if there is a room for improvement, different housing status influenced significantly the respondents in citing the factors like business hours and service, and the shape of product and service(p＜0.05).