• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.4
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• pp.819-827
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• 1992

Investigations of the fatigue damage of roughing mill roll and experimentally. By the computer simulation for analysing the stresses on the roll surface and experimental hot rolling, the following results were drawn : The crakcs observed on the roll surface were initiated thermally in the initial stage of the rolling and propagated by repeated thermal and bending stresses. The size of the roll surface cracks smaller than 4.87mm could avoid the occurrence of tiny scab, surface defect of hot steel strip. Since the size of surface cracks observed on the roughing mill roll was very small, the fatigue damage of roll surface was found not to be the major factor for the formation of the scab.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.1
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• pp.292-300
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• 1995

According to the number of cold-rolled coils, the amount of roll wear and thermal expansion, and roll gap profile were calculated, by using the actual data from the finishing mill. Also, based on those data, the calculations of the deflection, the flattening, and the contact pressure of vwork rolls and backup rolls were made respectively. Specially, in the calculation of contact pressure, the numerical results were obtained not only during the normal rolling, but also during the abnormal rolling, by modeling mathematically the dynamic impact force which occurs when the head section of the strip is threading through rolls. With those results the growth of the fatigue region and the fatigue damage of rolls were predicted. Also the optimum roll-grinding depth was determined to maximize the roll life.

• 프린팅코리아
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• v.8 no.2
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• pp.88-89
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• 2009

(주)지엠피(대표이사 김양평, www.gmp.co.kr)는 최근 RFID안테나 생산용 롤 코터의 개발에 성공했다고 발표했다. 지엠피는 지식경제부의 주관 사업으로 진행된 중기거점개발사업의 하나인 'RFID 안테나 생산용 롤코터' 개발사업의 주관기업으로 선정된 지난 2006년 6월부터 총26개월에 걸쳐 기술개발을 진행해 왔으며 최근 산업기술평가원이 심사한 최종평가 결과 '성공'이라는 평가를 받아 그동안의 노력이 결실을 맺게 되었다. RFID 롤 코터기 개발과제에는 총 기술개발사업비 10억3760만원이 투입되었으며 이 가운데 정부출연금은 7억7280만원, 지엠피의 현물부담금은 2억6480만원이 소요되었다. 이번에 성공으로 평가 받은 것은 그동안의 기술개발기간을 마무리하고 최종 시제품에 대한 기술평가 심사과정에서 성공적이라는 결과를 받은 것이어서 그 의의가 더욱 큰 것으로 평가되고 있으며 RFID 사용의 확산에 중요한 전기를 마련하게 될 것으로 보인다.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.3
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• pp.87-92
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• 2011

This study analyzes structural stress and fatigue on control arm of automobile under nonuniform load. Maximum equivalent stress at bolt part is shown with 419.1MPa and the corner is deformed with maximum displacement of 1.1628mm. Among 3 cases of nonuniform fatigue loads applying on control arm, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of $-10^5MPa$ to $10^5MPa$ and the amplitude stress of 0 MPa to $10^5MPa$, the possibility of maximum damage becomes 3%. This stress state can be shown with 6 times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. Safety and durability on automobile can be effectively improved by applying the fatigue analysis result on control arm.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.316-321
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• 2000

The role of fatigue on the surface damage of 5% chrome cold milling work roll is evaluated. Uniaxial and torsional fatigue tests are carried out, and the baseline data for fatigue life evaluation are established. An appropriate multiaxial fatigue parameter is developed from the fatigue data. Fatigue tests are also performed under compressive mean stresses, and a mean stress model is formulated. A computer program is developed to assess the interaction of fatigue and grinding of the roll. The fatigue damage is computed for selected servicing conditions. It is found that the fatigue damage can be an important issue when the effect of mean stress is ignored, however the fatigue damage is negligibly small when the effect of mean stress including the residual stresses currently used is fully accounted. The result indicates that spalling due to the growth of thermal shock cracks is more important than fatigue damage in roll surface failure.

• Journal of Navigation and Port Research
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• v.38 no.5
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• pp.485-491
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• 2014

In this paper, it is proposed that the effects of simulator sickness due to scene movement in ship handling simulator can be measured by using center of pressure (COP) and a simulator sickness questionnaire (SSQ). For experiments of simulator sickness, twelve participants are exposed to scenes movement from ship handling simulator according to three steps of sea states. During experiments, COPs for subjects are measured by force plate. After exposure to scenes movement, subjects describe their sickness symptoms by answering the SSQ. Throughput analysing the results of scene movement, SSQ, and COP, the relation between the simulator sickness and COP is investigated. It is suggested that formulations for SSQ score and COP with respect to sea state are obtained by the curve fitting technique, and the longitudinal COP can be used for measuring the simulator sickness.

• Proceedings of the Korea Contents Association Conference
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• 2018.05a
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• pp.195-196
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• 2018

본 연구는 비비안 마이어의의 셀프포트레이트 창작 방식에 대해 탐구했다. 비비안 마이어는 셀프포트레이트 촬영을 통해 자신의 모습을 사진의 피사체로 적극적으로 활용했다. 특히 거울이나 유리 등에 비친 자신의 모습을 정방향의 프레임인 롤라이플렉스 카메라로 촬영함으로써 내면적 자아의 모습을 정직하게 담아내고 있다. 또한, 주변 배경에 대한 자신의 정서가 반영됨으로써 그 시대의 생활상이 상징적으로 나타나고 있다.

• Transactions of Materials Processing
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• v.6 no.2
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• pp.95-101
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• 1997

The thermal fatigue and wear properties of high speed steel roll which was recently developed were investigated by observing microstructure, by measuring mechanical and physical properties, by conducting thermal fatigue testing, and by measuring the amount of wear in actual mill. High speed steel roll had better thermal fatigue testing, and by measuring the amount of wear in actual mill. High speed steel roll had better thermal fatigue life than high chromium iron roll, which was due to lower carbide content, higher strength, and higher thermal conductivity. The amount of wear of high speed steel roll was nearly the same as that of high chromium iron roll in the first finishing stand, which was due to the oxide formation on the roll surface. However, in the third finishing stand, the wear resistance of high speed steel roll was 2~3 times as good as that of high chromium iron roll because the former had higher hardness at high temperature.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.493-496
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• 2008

Recently, shortage of natural aggregates resources and the amount of waste concrete hsve been rapidly increased, the technique of aggregates manufacturing of waste concrete is damanded. In this study, we evaluated the performance of gutter type roll crusher. Gutter type roll crusher is showed enhanced producing manufacturing ability. The gutter type roll crusher achieved more friction energy than general roll crusher, also a mount of producing showed same results.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.5
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• pp.683-688
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• 2009

The purposes of this paper is to propose new techniques to reconstruct measured optical images by using the template matching and B-Spline interpolation method based on image processing technology. To do this, we detect the matching template and non-matching template from each optical image. And then, we match the overlaped images from base level by correcting roll, pitch, and yaw error of images. At last, the matching image is interpolated by B-Spline interpolation. Finally, we show the effectiveness and feasibility of the proposed method through some experiments.