• 산업경영시스템학회지
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• 제41권4호
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• pp.213-219
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• 2018

Mechanical components are to be produced with accurate dimensions in order to function properly in assemblies of a machine. Once designs of mechanical components are created, designers examine the designs by adopting many known experimental methods. A primary test method includes stress and strain evaluation of structural parts. In addition, fatigue test and vibration analysis are an important test method for mechanical components. Real experiments at a laboratory are established when products are manufactured. Since design changes should be done before producing the designs in factories, rapid modifications for new designs are required in production industries. FEM simulation is a proper choice for a design evaluation with speed at a detail stage in design process. This research focuses modeling and mechanical simulation of a mechanical component in order to ensure structural safety. In this paper, a universal joint, being used in driving axels of vehicles, is studied as a target component. A design model is created and tested in some ways by using commercial software of FEM. The designed component is being twisted to transmit heavy power and thus, torsional stress should be under strengths of the component's material. The next is fatigue analysis to convince fatigue cycles to be within the endurance limit of the material. Another test is a vibration analysis for rotational components. This research draws final conclusions from these test analyses and recommends whether the designed model is under safety condition in terms of mechanical structure.

• 한국기계가공학회지
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• 제7권3호
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• pp.36-40
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• 2008

This study is analyzed by the simulation of automotive steering system. The maximum equivalent stress of $2.2418{\times}109Pa$ and the maximum total displacement of 0.014929m are shown at the universal joint and its lower part respectively. As the minimum cycle of 34.047 is shown at the universal joint in case of fatigue analysis, it is possible to have greatest damage at this part. In case of natural frequency analysis at vibration, its frequency of 47 to 59Hz is occurred generally. The maximum total displacement of 0.5m is shown at handle on the natural frequency of 57 to 58Hz. And the displacement over 2m is shown at the lower part of universal joint on the natural frequency of 58 to 59Hz. As the basis of the simulation analysis of steering system, passenger's comfort of car body can be improved in the design of practical part and the design effect necessary to safe driving can be promoted.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 A
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• pp.247-249
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• 1998

This paper has proposed an optimized universal motor for improving its performance and cost using FEM program. To do this, various design parameters are set such as air gap length, shape of stator and pole shoe, rotor slot, rotor shaft diameter, etc. As results, the optimized model has made good improvement compared with those of the initial.

• 교육시설
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• 제24권2호
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• pp.13-17
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• 2017

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권11호
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• pp.5625-5641
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• 2017

Certificateless public key cryptography resolves the certificate management problem in traditional public key cryptography and the key escrow problem in identity-based cryptography. In recent years, some good results have been achieved in speeding up the computation of bilinear pairing. However, the computation cost of the pairing is much higher than that of the scalar multiplication over the elliptic curve group. Therefore, it is still significant to design cryptosystem without pairing operations. A multi-signer universal designated multi-verifier signature scheme allows a set of signers to cooperatively generate a public verifiable signature, the signature holder then can propose a new signature such that only the designated set of verifiers can verify it. Multi-signer universal designated multi-verifier signatures are suitable in many different practical applications such as electronic tenders, electronic voting and electronic auctions. In this paper, we propose a certificateless multi-signer universal designated multi-verifier signature scheme and prove the security in the random oracle model. Our scheme does not use pairing operation. To the best of our knowledge, our scheme is the first certificateless multi-signer universal designated multi-verifier signature scheme.

• 한국실내디자인학회논문집
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• 제24권4호
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• pp.111-123
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• 2015

This study aims to suggest 'an eco-friendly residential housing design guideline as an elderly housing alternative' by mixing the concept of a 'senior citizen community' housing environment with the concept of an 'eco-friendly' housing environment, based on the directivity of an elderly housing alternative for surviving in a super-aged society and the directivity of a sustainable housing environment for providing against global warming. Basically, this study considered the directivity of 'an eco-friendly residential building as an elderly housing alternative' by analyzing housing environment elements and elements to be considered in an elderly housing environment and setting the directivity of an elderly housing environment, which reflects the change in the design paradigm. In relation to the concept of universal design, for considering the perspective of elderly users, existing elements were compared and major planning elements were applied to the scope of complex planning, communal space and housing unit space. In relation to the concept of eco-friendly design, also, a guideline was re-organized and planning elements were applied to each category by comparing domestic and foreign green building certification systems. Based on domestic and foreign authorized guidelines of universal design and green building certification systems, this study was focused on suggesting an eco-friendly residential housing design guideline as an elderly housing alternative to make users perceive the need for a specific indoor environment design guideline and system.

• 한국환경생태학회지
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• 제23권1호
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• pp.78-89
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• 2009

유니버설디자인은 '모두를 위한 디자인'이고 '적응 가능한 디자인'으로 생활권 숲길에서 도입 필요성이 높다. 본 연구는 유니버설디자인 7원칙을 기본으로 정비한 생활권 숲길인 경상북도 포항시 도음산과 강원도 춘천시 안마산을 대상으로 숲길 보행시설의 중요도-성취도 분석으로 이용객 평가를 실시하여 효율적인 유니버설디자인 적용 숲길 조성을 위한 기초자료 제공을 목적으로 하였다. 이용객 평가는 설문조사로 하였으며, 포항 도음산에서 134부, 춘천 안마산에서 113부 총 247부의 응답 자료를 분석에 이용하였다. 응답자 거주지는 포항 도음산, 춘천 안마산 모두 주변 거주자가주를 이루었다. 도음산의 방문목적은 자연관찰과 교육이라는 응답 비율이 가장 높았고, 안마산은 건강을 위한 숲길이용이 주를 이루어 생활권 숲길 이용 행태의 전형적인 유형이었다. 포항 도음산의 중요도-성취도 분석 결과 중요도 평균값은 3.87, 성취도 평균값은 4.04로 높았다. 이는 유니버설디자인 적용 숲길의 시설 정비에 대해 매우 긍정적인 평가를 하였기 때문에 나타난 결과로 생각된다. 유도 및 안전 핸드레일의 안전·편리성과 안내사인의 내용을 쉽게 이해할 수 있도록 고려할 필요가 있으며, 이용목적에 부합하도록 생태해설 사인 도입이 요구된다. 또 숲길 접근 편리를 위해 노면 단차를 없애는 관리가 필요하다. 춘천 안마산에서 중요도 평균값은 3.92, 성취도 평균값은 3.99이었으며, 노면포장재료와 경계안전시설의 안전성 개선이 필요한 것으로 판단된다.

• 월간포장계
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• 통권142호
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• pp.112-116
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• 2005

• 월간포장계
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• 통권142호
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• pp.107-111
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• 2005

• 월간포장계
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• 통권142호
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• pp.102-106
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• 2005