• 한국자동차공학회논문집
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• 제21권5호
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• pp.34-39
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• 2013

The gear shifting timing of a manual transmission vehicle is influencing fuel economy. This paper focuses on an gear shifting indicator of an city bus with manual transmission, which can improve fuel economy. The shift indicator is supposed to collect the vehicle data during driving, calculate and compare fuel economy with and without gear shifting, and indicate the proper gear shifting timing. The H/W and S/W of the shift indicator are developed and tested on city bus in this research. The experiments are carried out on real road by 3 different drivers and the results show the improvement of fuel economy from 6.0% to 21.4%. The average engine torque and speed are reduced due to early gear shifting and the usage of highest gear is increased. The results of chassis test are also performed and show 7.5% improvement of fuel economy.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 춘계학술대회
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• pp.371-373
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• 2018

자전거 등하교 및 출퇴근족의 안전을 위하여 방향 표시등의 기능은 반드시 필요하다. 본 연구에서는 아두이노를 활용하여 조립식 자전거에 방향 표시등 기능을 개발하였다. 아두이노의 간단한 기능을 통해 핸들에 스위치를 부착하여 방향 표시등을 켜고 끄게 할 수 있다. 또한 간단한 기능이므로 자전거를 가지고 있는 사람들이 스스로 DIY를 하여 제작할 수 있는 메이커 활동으로 적합하다고 판단된다. 본 논문에서 제안된 기능을 통하여 자전거에 필요한 서비스를 많이 부착할 수 있는 가능성을 열어두었다.

• Journal of Mechanical Science and Technology
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• 제20권12호
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• pp.2178-2188
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• 2006

The stress collapse in the formation of shear bands in elasto-thermo-viscoplatic materials is systematically studied within the framework of one-dimensional formulation via analytical and numerical methods. The elastic energy released in a domain is found to play an important role in the collapse behavior of shear localization. A non-dimensional parameter named the stability indicator is introduced to characterize the collapse behavior, with approximate forms of the incremental governing equations. The stability indicator offers useful information regarding the degree of severity of an abrupt change of deformations during the stress collapse. Numerical experiments are carried out to verify the stability indicator by varying material properties.

• 대한기계학회논문집B
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• 제23권3호
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• pp.398-407
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• 1999

In the present image processing technique, the concept of the gradient indicator(GI) has been introduced to find out the depth-of-field in sizing large particles ranging from $30{\mu}m$ to $30{\mu}m$ where using of the concept of the normalized contrast value(VC) is not appropriate. The gradient indicator is defined as the ratio of the local value to the maximum possible value of the gray-level gradient in an image frame. The gradient indicator decreases with the increases of the particle size and the distance from the exact focal plane. A particle is considered to be in focus when the value of the gradient indicator at its image boundary stays above a critical value. This critical gradient indicator($GI_{critical}$) is defined as the maximum gradient indicator($GI_{max}$) subtracted by a constant ${\Delta}GI$ which is to account for the particle-size effect. In the present ca.so, the value of ${\Delta}GI$ was set to 0.28 to keep the standard deviation of the measured particles mostly within 0.1. It was also confirmed that, to find the depth-of-field for small particles(${\leq}30{\mu}m$) with the same measurement accuracy, tho concept of the critical normalized contrast($VC_{critical}$) is applicable with 85% of the maximum normalized contrast value($VC_{max}$). Finally, the depth-of-field was checked for the size range between $10{\mu}m$ and $300{\mu}m$ when the both in-focus criteria ($GI_{critical}$ and $VC_{critical}$) were adopted. The change of the depth-of-field with the particle size shows good linearity in both the VC-applicable and the GI-applicable ranges with a reasonable accuracy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.2055-2056
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• 2006

From composition transmitter is detached in indicator to individual load direction of 4 channels and adding up display by load cell indicator indication method of Bluetooth way is identifying marks.

• Journal of Mechanical Science and Technology
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• 제20권12호
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• pp.2189-2196
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• 2006

The present work is concerned with the development of a procedure for adaptive computations of shear localization problems. The maximum jump of equivalent strain rates across element boundaries is proposed as a simple error indicator based on interpolation errors, and successfully implemented in the adaptive mesh refinement scheme. The time step is controlled by using a parameter related to the Lipschitz constant, and state variables in target elements for refinements are transferred by $L_2$-projection. Consistent tangent moduli with a proper updating scheme for state variables are used to improve the numerical stability in the formation of shear bands. It is observed that the present adaptive mesh refinement procedure shows an excellent performance in the simulation of shear localization problems.

• Structural Engineering and Mechanics
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• 제35권2호
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• pp.127-140
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• 2010

This paper focuses on a number of criteria that enable controlling the influence of geometric simplification on the quality of finite element (FE) computations. To perform the mechanical simulation of a component, the corresponding geometric model typically needs to be simplified in accordance with hypotheses adopted regarding the component's mechanical behaviour. The method presented herein serves to compute an a posteriori indicator for the purpose of estimating the significance of each feature removal. This method can be used as part of an adaptive process of geometric simplification. If a shape detail removed during the shape simplification process proves to be influential on mechanical behaviour, the particular detail can then be reinserted into the simplified model, thus making it possible to readapt the initial simulation model. The fields of application for such a method are: static problems involving linear elastic behaviour, and linear thermal problems with stationary conduction.

• 대한기계학회논문집A
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• 제25권9호
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• pp.1444-1451
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• 2001

The evolutionary structural optimization(ESO) method has been under continuous development since 1992. The bidirectional evolutionary structural optimization(BESO) method is made of additive and removal procedure. The BESO method is very useful to search the global optimum and to reduce the computational time. This paper presents the ranked bidirectional evolutionary structural optimization(R-BESO) method which adds elements based on a rank, and the performance indicator which can estimate a fully stressed model. The R-BESO method can obtain the optimum design using less iteration number than iteration number of the BESO.

• 실천공학교육논문지
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• 제5권2호
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• pp.123-127
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• 2013

청년취업아카데미 사업은 대학 졸업예정자 및 졸업생을 대상으로 산업계 주도의 맞춤형 취업역량향상 프로그램을 지원함으로써, 산업현장에 맞는 인재를 양성하고 청년실업의 구조적 수급불일치 해소를 목적으로 한다. 이 사업의 주요 특징 중의 하나는 기업맞춤식 교육에 있어서 M-to-M 모델을 적용하여 여러 기업에 공통적으로 적용될 수 있는 업종별 공통기술을 교육한다는 점이다. 청년 취업아카데미 사업의 운영기관은 사업시작 후 1년 6개월이 지난 시점에서의 최종 취업률에 의해 평가를 받으므로 중간평가의 의미를 가지는 운영기관 성과지표가 개발되어 사용되고 있다. 본 연구에서는 운영기관 성과지표의 타당성을 분석하였다. 성과지표와 성과평가 결과, 성과평가 결과와 최종 취업률 그리고 성과지표와 최종 취업률간의 상관관계를 분석하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.593-596
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• 2008

The reed switch position transmitter (RSPT) is used as a position indicator for the control rod in commercial nuclear power plants made by ABB-CE. But this position indicator has some problems when directly adopting it to the integral reactor. The Control Element Drive Mechanism (CEDM) for the integral reactor is designed to raise and lower the control rod in steps of 2mm in order to satisfy the design features of the integral reactor which are the soluble boron free operation and the use of a nuclear heating for the reactor start-up. Therefore the resolution of the position indicator for the integral reactor should be achieved to sense the position of the control rod more precisely than that of the RSPT of the ABB-CE. This paper adopts seismic resistance reed switches to the position indicator in order to reduce the damages or impacts during the handling of the position indicator and earthquake.