• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.5
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• pp.104-110
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• 1998

In automotive industries, various processes for the cost reduction have been investigated lively. As one of them, powder metallurgy becomes influential. Compared to other methods used for he manufacture of steel components the Powder metallurgy process is competitive primarily due to the small number of production steps to reach the final geometry and thereby also the energy-efficiency. In this paper, to alter present forging process into powder metallurgy process by which the automotive clutch disc spline hub is manufactured machining process, the mechanical properties of sintered materials is investigated by specimen test. Selecting the 3 kinds of materials-SMF 4040, SMF 9060 and DHP-1, their properties according to heat treatment such as carburizing -tempering and plasma-nitrodizing are compared. By result of specimen test - tensile test, compression ring test, Impacting test, measurment of hardness, and microstructure analysis - we concluded that SMF 9060 and carburizing-tempering heat treatment is an optimal material and heat treatment method for the spline hub. It will be able to reduce manufacturing cost and weight.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.2
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• pp.166-173
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• 2002

The wheel bearing hub unit is developed type of wheel bearing unified with the hub parts. It has advantage of reducing the weight and the number of components. And, it also improves uniformity of manufacturing quality, In order to design the wheel bearing hub units, many techniques are used such as load analysis, structure analysis and bearing characteristics analysis and so forth. These techniques need highly accurate load conditions founded on service conditions. In this study, to design the wheel bearing hub units used widespread in passenger cars, the service load was measured through driving tests on the public roads and in the special events. The public roads are classified into highway, intercity road, rural road, urban road, and unpaved road so as to know what the characteristics of the road loads are. The results of the tests showed that the wheel force was relative to the lateral acceleration, and also could be calculated from the lateral acceleration. The lateral acceleration was measured from 0.0G to 0.6G in general driving on the public roads, with different distributions in each road type. In special events, the maximum lateral acceleration was measured from 0.8G to 1.3G.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.11a
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• pp.234-236
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• 2018

현대 사회에서 항만이 전반 공급체인에서 차지하는 역할이 날로 중요해지고 있다. 항만의 역할은 이미 단순한 하역작업이 아닌 화물에 부가가치를 부여하는 중요한 경제활동중심으로 진화하였다. 이러한 항만의 중요성으로 인해 각국은 모두 허브항 육성을 주요 성장전략으로 삼고 있다. 특히 동북아시아는 대형 항만이 가장 밀집된 지역으로 되어 항만 간 경쟁이 매우 치열하다. 부산항은 배후단지 활성화를 통한 안정적인 물동량 유치를 통해 역내에서 경쟁력을 확보하고 있다. 본 연구는 부산항 신항 배후단지에서 처리하는 주요 화물들의 원단위를 산정하여 실제 부산항 신항 배후단지에서 창조하는 부가가치에 대해 정량적으로 분석하였다. 분석결과, 케미칼 제품, LME 벌크, 자동차 부품, LME 컨테이너, 일반화물, LME 내륙운송의 순으로 원단위 비용이 점차 감소하였다. 향후 연구에는 부산항 신항 배후단지에서 취급되는 전체 화물에 대한 세부적인 연구가 이루어질 필요가 있다. 이를 통해 항만이 창출하는 가치를 보다 정밀하게 파악하고 효과적인 물동량 유치 전략을 실행할 수 있다.

• Journal of Distribution Research
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• v.7 no.1
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• pp.1-20
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• 2002

Many of logistics-related research in automobile industry has focused on inbound logistics and procurement. Research into outbound logistics is relatively few. As a starting research into outbound logistics in automobile industry, this paper examined its logistics network problems with three aspects - location strategy, inventory strategy and transportation strategy. We proposed alternatives of logistics network design resolution, and presented three practical scenarios based on those alternatives. Based on interview, on-site visit and internal data collection processes, we identified major domestic outbound logistics problems such as redundant logistics bases, inefficient delivery policy, insufficient inventory capacity, inventory stock quality deterioration, inefficient transportation system, and etc. In order to cope with those problems, we proposed such strategic alternatives as introduction of hub-and-spoke system, integration of logistics bases, introduction of (automatic) parking building, diversification of transportation mode, and etc. At the same time, we constructed three practically executable scenarios based on those ideas. The first is "Center Hub" scenario, the second is "Metropolitan Hub" scenario. The third and last scenario is "Regional Consolidation of Warehouses (distribution centers)".

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.725-732
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• 2017

Weight reduction is one of the important issues in the automotive industry and the development of internal combustion engines vehicles, future vehicles, and eco-friendly vehicles for improving fuel efficiency. The objective of this study is to investigate the improvement of driving performance by weight reduction and optimum design for a formula-type self-designed on-road vehicle. This study is divided into the four steps. Firstly, the engine room was replaced and designed with a lighter engine. Secondly, an optimization study was conducted to simplify and lighten the vehicle components with the design of the frame. Thirdly, the structure design was optimized and the suspension was analyzed with the design of the frame. Finally, the design of an upright and hub with reduced weight was carried out using lighter parts. As a result, we reduced the weight of the vehicle by 48.5kg compared to the previous year (19.5%) and increased the acceleration from 6.8 s to 5.8 s.s.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.29-36
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• 2008

In this paper, the orbital forming analysis of an automotive hub bearing was studied to predict forming performances using the explicit finite element method. To find an efficient solution technique for the orbital forming, axisymmetric finite element models and 3D solid element models were solved and numerically compared. The time scaling and mass scaling techniques were introduced to reduce the excessive computational time caused by small element size in case of the explicit finite element method. It was found from the numerical simulations on the orbital forming that the axisymmetric element models showed the similar results to the 3D solid element models in forming loads whereas the deformations at the inner race of bearing were quite different. Finally the strains at the inner race of bearing and the forming forces to the peen were measured for the same product of the numerical model by test, and were compared with the 3D solid element results. It was founded that the test results were in good agreements with the numerical ones.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.142-151
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• 2005

To predict the fatigue life of the Hub Bearing Unit(HBU), preload effect and initial axial clearance have to be considered. Various theory and equations for the HBU design used in the passenger car are well developed in many literatures. But most design hand book for bearings or bearing catalogues do not consider the initial axial clearance and preload effect. So there are limits and difficulties to use those data in actual bearing design. To consider the preload effect and initial axial clearance, complex elliptic integrals and nonlinear equations are involved. These equations are difficult to solve during the design process. In order to solve these problems effectively, a program is developed to solve these equations reliably and to help the designer in obtaining the performance data of the HBU such as load distribution, maximum contact stress and fatigue life. The preprocessor of the program helps users to prepare the input data through a dialog box and the post processor makes graphical presentation of the result. In this paper, theoretical and numerical background for the prediction of the fatigue life of the HBU is explained. A simple example is presented to show the usefulness of developed program.

• Journal of Korea Society of Industrial Information Systems
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• v.26 no.5
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• pp.79-94
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• 2021

Despite the importance of the supply chain risk due to the negative word-of-mouth (NWOM) in social media, related research is insufficient. Thus, this study analyzes how the NWOM of the product is distributed through social media and the characteristics of the distributor based on social exchange theory. For this purpose, we collected information on car recalls from four companies using Twitter from the National Highway Traffic Safety Administration (NHTSA). Based on the Seed Tweet, a Re-Tweet (RT) network was constructed to examine the distribution and spread of NWOM, and regression analysis was performed to test the hypothesis. As a result, it was confirmed that NWOM is a small world network structure that spreads around hub users connected to many users. Moreover, it was found that the more interactive and reciprocal relations the first distributor has, the greater the speed and scale of distribution of NWOM.

• Journal of the Economic Geographical Society of Korea
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• v.24 no.3
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• pp.243-258
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• 2021

By using the trade in value-added(TiVA) database and employing social network analysis, this paper analyzes changes in global trade to be triggered by the Belt and Road Initiative (BRI) and the US-China trade war. The main results are summarized as follows. First, the BRI will help maintain China's core position as the world's manufacturing hub, and will strengthen Europe's service industry capabilities within the global value chain(GVC) network. Second, the US R&D industry, US wholesale and retail industries, and Germany's automobile industry were considered the most influential industries in the GVC network during the 1995-2011 period, and will retain their status until 2049, when the US-China trade war and the BRI are reflected. Third, the increase of the number of communities shows that the BRI might spur fragmentation of the production process. Finally, community structures of inter-industry trade relations, including China's electronics industry, Germany's automobile industry, and US R&D, show important features that are related to the competiveness of each country's service industries.

• The Magazine for Energy Service Companies
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• s.79
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• pp.30-35
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• 2012

작년 9월 15일, 정전대란이 일어났다. 우리나라도 이제 전력 수요가 많아짐에 따라 블랙아웃에 절대 안심할 수 없는 지경에 이르렀다. 최근 전력수급과 에너지 효율성 등에 대한 관심이 커지고 있는 시점에 열린 2012 대한민국 녹색에너지대전은 '제4의 에너지'로 일컬어지는 신재생과 '제5의 에너지'인 에너지절약을 강조하는 행사로 다양한 에너지 문제에 대한 다양한 해법을 제시하였다. 지난 10월 9일부터 12일까지 코엑스에서 열린 '2012 대한민국 에너지대전'에서 대체에너지 생산과 에너지절약에 대한 지혜를 발견할 수 있었다. 녹색에너지대전, 신재생에너지대전, 녹색일자리엑스포 등 3가지 행사를 한 자리에서 볼 수 있었으며 '에너지절약시설자금 투자설명회'가 개최 돼 녹색에너지와 에너지절약을 궁금해 하는 일반인들과 에너지절약기업의 큰 관심을 끌었다. '2012년 대한민국 녹색에너지대전'은 에너지, 기후, 신재생 분야의 최신 제품, 기술, 정보 등 녹색 교류의 장이자, 동북아대표 기술교류 허브(Hub)로써 에너지효율, 기후변화-신재생에너지등 미래 에너지의 새로운 패러다임을 제시한 행사로 평가된다. 또한 에너지절약 차원으로는 에너지효율 향상을 주도하는 제품 및 기술 제안하여 보일러, 고효율조명, LED, 단열재, 하이브리드 자동차, 고효율가전기기, 전력수요관리설비 등 에너지효율 향상 제품이 전시되었고 기후변화대응과 녹색정책 및 기술 발표가 이어져 에너지 관련 공공기관, 협회 등 정책, 사업, 기술동향 등(CDM프로젝트, 탄소배출권 거래체, 탄소금융 사업 등)이 소개되었다.