• 한국자동차공학회논문집
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• 제17권2호
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• pp.112-117
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• 2009

The new suspension, called ISU(In-arm suspension system) was developed for Infantry Fighting Vehicle. During vehicle field test, early failure of ISU's sealing system was occurred after driving the paved road. From the failure analysis, ISU's displacement data was obtained. In analysis of PSD data, track induced vibration which has high frequency and small amplitude characteristics, was dominant. Such track vibration would result in early seal failure because of friction increase and lack of lubrication. To simulate track vibration environment in laboratory, seals were tested under the condition of 20Hz, ${\pm}1$, ${\pm}2mm$ amplitude. The same type of seal failure occurred in vehicle test, was reproduced in the lab test under ${\pm}1mm$ amplitude. From the test results, the durability of improved seal was increased by 2.5 times compared with the previous one.

• Tribology and Lubricants
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• 제26권1호
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• pp.61-67
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• 2010

The purpose of this paper is to study and analyze the failure examples on tribological characteristics of an automotive steering system. In this failure study, the grease leakage may stick leaked grease, dust, and wear particles between pinion and rack gears in mechanical steering system. In the case of seal failures such as a rod seal, o-ring and oil seals, the gear box and oil pump do not operate properly due to lack of oils. This means that oil pump does not supply a working fluid and produce a normal oil pressure of the steering system. This leads to leak a working fluid from the seals and produce a wear between pinion and rack gears. Especially, the leaked oil is usually mixed with internal wear particles and foreign dust/fine sands. Thus no leakage of working oils is very important design concepts, which is strongly related to the sealing components and smoothly operating of the mechanical friction parts of power steering system.

• 드라이브 ㆍ 컨트롤
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• 제15권1호
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• pp.10-15
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• 2018

The hydraulic cylinder seals are used not only to protect leakage of the working fluids but also to prevent incoming of foreign particles into the system. Chromium plating is generally applied to improve corrosion and wear resistance. It has been noticed that sealing surface damage occurs due to the hard foreign/wear particles contained in the hydraulic oil. In this study, a three-bodied sliding contact problem related with a PTFE seal, a spherical particle and chrome-plated steel substrate is modeled to investigate the relations to wear mechanism. Using the nonlinear finite element software, MARC/MENTAT, the deformed shapes, the von Mises and first principal stress distributions with plating thickness were compared. The sealing surface was mainly abraded by hard particles embedded in the seal. The plastic deformation of the steel substrate decreased with thicker plating. Hence it could be more effective to coat the sealing surface of a hydraulic cylinder with a hard material such as TiN, TiC and DLC.

• 스마트미디어저널
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• 제4권4호
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• pp.93-100
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• 2015

현재 국내 출판계의 전자책과 앱북 시장은 장르문학인 소설과 웹툰 분야의 매출이 전체의 80%에 이르는 특정분야 매출 편중 현상이 두드러지게 나타나는 상황이다. E-book에서 진화한 앱북은 오프라인에서 주로 판매되는 종이책과는 달리 가독성과 구매의 편리함이 강점이지만 일반화되기에는 대중적 전파력에 있어 시일이 걸린다는 점이 단점으로 작용하기도 한다. 그러한 상황 속에서도 국내 전자책 시장의 매출은 가파르게 성장하고 있으며 현재는 장르문학에 국한되지 않고 출판콘텐츠 분야에서 다양한 실험적 도전이 시행되고 있는 단계라고 할 수 있다. 본 연구는 부산관광콘텐츠를 기반으로 한 최초의 지역콘텐츠 소재 앱북의 기획과 개발과정을 통해 향후 웹 모바일 플랫폼으로서 관광 앱북을 개발하고 기존의 단순한 정보만을 제공하는 앱북의 단점들을 보완하여 유료다운로드를 통한 구매로 이어지는 지속적 사용이 가능한 여행 앱북의 활용 전략을 제안하고자 한다.