• 대한산업공학회지
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• 제27권3호
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• pp.233-238
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• 2001

This paper deals with demand forecasting of parts in an automobile model which has been extinct. It is important to estimate how much inventory of each part in the extinct model should be stocked because production lines of some parts may be replaced by new ones although there is still demands for the model. Furthermore, in some countries, there is a strong regulation that the automobile manufacturing company should provide customers with auto parts for several years whenever they are requested. The major characteristic of automobile parts demand forecasting is that there exists a close correlation between the number of running cars and the demand of each part. In this sense, the total demand of each part in a year is determined by two factors, the total number of running cars in that year and the failure rate of the part. The total number of running cars in year k can be estimated sequentially by the amount of shipped cars and proportion of discarded cars in years 1, 2,$\cdots$, i. However, it is very difficult to estimate the failure rate of each part because available inter-failure time data is not complete. The failure rate is, therefore, determined so as to minimize the mean squared error between the estimated demand and the observed demand of a part in years 1, 2,$\cdots$, i. In this paper, data obtained from a Korean automobile manufacturing company are used to illustrate our model.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.765-766
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• 2009

• International Journal of Automotive Technology
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• 제7권7호
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• pp.853-858
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• 2006

The method of die-face design based on the CAE platform for automobile panels can fast modify the die addendum. In contrast with the process of the die-face design based on the CAD platform, there are some special steps for the die-face design based on the CAE platform. The most obvious difference is that the auto-body part contour needs smoothing arlier than the design of addendum surfaces does. It is helpful to improve the design quality of addendum surface. In spite of extensive researches on the smoothing technique, here is still dearth of the published solutions about smoothing the part contour with additional surface. This paper attempts to analyze the difficulties and provides practical solutions. Main results include the algorithm to calculate the segments needing to be smoothed on boundary, the strategy to create the smoothing curve and the procedure of surface generation. The relevant function modules for parametric design are developed. A few examples and suggestions for future work conclude the paper.

• Tribology and Lubricants
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• 제25권2호
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• pp.120-124
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• 2009

In automobile chassis system, several environmental factors weaken durability of automobile's components. The environmental factors are temperature, humidity, intensity of radiation and dust particle inflow. Especially, dust particle inflow leads to increase in friction and wear of automobile's components. The wear of automobile's component leads to increase in noise and exerts a bad influence on life of components. In this study, dust particles were investigated for study on the influence of dust particle inflow. Dust particles are collected on urban area, rural area and highway in China. The size of dust particle is analyzed using the image plus program, and the element of dust particle is analyzed using the SEM and EDX. The elements of dust particle are $SiO_2$ and $Al_{2}O_{3}$. The other elements(Na, Ca, Cl etc..) are detected on urban area and highway.

• Journal of Mechanical Science and Technology
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• 제14권4호
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• pp.466-476
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• 2000

This paper presents atomization characteristics of a double impinging F -0-0- F type injector with four streams. A phase Doppler particle analyzer was employed to measure the droplet-size and water was used as the inert simulant liquid instead of reactive propellant liquids. The droplet mean diameter (SMD) and size distribution were measured to investigate the effects of the momentum ratio and pressure drop variations. This experimental results can be used during the preliminary design stage of a impinging stream type injector for liquid rockets.

• 자동차안전학회지
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• 제15권2호
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• pp.49-55
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• 2023

In this study, it was analyzed that it is necessary to clarify the quality certification parts system, to make certification codes mandatory for self-certification products that are normally distributed, and to conduct follow-up management so that prompt action and thorough management of test reports are necessary in case of defects. Big data-based data, the detailed number of parts replacement cases, parts cost by part group, share, average labor cost, calculated to analyze the detailed automobile parts industry, and automobile parts certification system and automobile parts market in major countries including Korea and Through the distribution structure analysis, improvement plans for the automobile quality certification parts system were derived.

• 한국산업경영시스템학회:학술대회논문집
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• 한국산업경영시스템학회 2002년도 춘계학술대회
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• pp.217-226
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• 2002

Under the sudden change of competitive environment, the economic cooperation as a part of survival strategy is being a big issue among countries. There was much discussion based on the geological adjacency as well as cultural homogeneity regarding the economic cooperation of three countries, Korea, China, Japan. It has been also known that major trade countries of the world concluded the treaty of region trade, then extended the number of export, and drew a success in foreign direct investment. Resent automobile industry is being ran by the center of America, Europe and Japan. Korea only has a successful experience of restoration of automobile industry in the half of a century after his beginning. It is true that China is trying to do best to raise his automobile industry. Also Japan is a leading automobile country guiding automobile industry all over the world. It can be considered that Korea will play a major role in the three countries' automobile industry based on Japanese demonstrated technology, Chinese resources, market and experience with their economic cooperation. Therefore it is expected that a big result will be achieved throughout such a role play of each country. This paper has a purpose to light up the distinctive quality and the present condition of each country in automobile Industry, and to promote the foundation of three countries' economic cooperation. It is convinced that the economic cooperation of three countries, Korea, China and Japan in automobile industry, will play a great role in the world automobile market.

• 한국공작기계학회논문집
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• 제10권6호
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• pp.63-70
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• 2001

This study is concerned with Finite Element Analysis on welded part of control link fur automobile. For analysis, control link was modeled into two parts, ring and rod. Heating condition, temperature distributions and fatigue fracture strength were analyzed using "HEAT III" and "NDURE" module of NISA II. Metal flow in the process of welding was simulat- ed by $DEFORM^{TM}2D$.The analyzed results were compared with experimental inspection. Quality of welded part was able to be improved by controlling metal flow in the process of welding by increase the friction constant of ring part. Heat transfer analysis and flow simulations were in good agreement wish welding experiments.

• 디지털융복합연구
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• 제19권1호
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• pp.67-75
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• 2021

국내 수입차량 판매 증가에도 불구하고 부품 물류센터의 판매 예측에 관한 연구는 매우 부족한 현실이다. 이러한 측면에서 본 연구는 부품 물류센터의 상위 판매 상품에 대한 판매 예측을 수행 하는 것을 연구의 목적으로 한다. 연구는 판매 예측에 대한 동적특성과 영향을 주는 변수의 인과관계 및 피드백 루프를 고려할 수 있는 시스템 다이내믹스 방법론을 도입하였다. 연구결과 'Oil'의 경우 시간이 지날수록 소모품 판매 수량이 증가하는 패턴을 보이고, MAPE을 실시한 결과 31.3%의 합리적 예측모델로 평가되었다. 상품 'Battery'의 경우 실제 데이터와 예측 데이터 모두 매년 10월을 기점으로 판매가 증가하여 12월에서 가장 높은 판매를 보이고 다음해 2월부터 감소하는 계절성 판매패턴을 보였다. 본 연구는 기존 연구에는 존재하지 않았던 특정 수입 자동차 부품 물류센터의 실제 데이터를 확보하고, 시스템 다이내믹스를 통하여 미래 판매 물동량 예측을 정량적으로 분석하여 제시하였다는 점에서 학문적 시사점을 갖는다.

• 무역학회지
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• 제44권3호
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• pp.253-269
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• 2019

This study examines the utilization effect of FTA on the sales and profit of the secondary auto-part suppliers in two aspects: 1) firm-level survey on the utilization of FTA and 2) statistical inference on the FTA effects on their sales and profit. We use the GLS statistical technique, panel and survey data of 130 secondary auto-part suppliers in the Daegu and Kyungpook area in 2007-2016. The evidence shows that the secondary auto-part suppliers struggle to prepare documents for the FTA certificates of origin due to their small firm size, although they utilize the FTA at the relatively high rate of 92 percent. Statistical evidence shows that an increase in the export of the first vender significantly affects the sale of the secondary auto-part vendors, but not their profit. The low profit and high managing cost of utilizing the FTA deteriorate the utilization effect of the FTA of the secondary auto-part vendors, which is a key factor in a global supply chain and for the competitiveness of the automobile industry. Government policies are required for the secondary auto-part suppliers to utilize the FTA more effectively and share the benefits of tariff reduction with first auto-part vendors under FTA transaction.