• 자원리싸이클링
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• 제28권4호
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• pp.37-43
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• 2019

현재 우리나라의 차량 증가에 따른 폐차도 증가추세에 있어 이에 따른 각종 환경오염 문제로 인해 자원 재순환에 대한 관심이 고조되고 있는 실정이다. 본 연구에서는 국내 자동차 부품 재제조시장의 사업도입에 따른 경제적 효과를 정량적으로 평가하고자 자동차의 부품중 상대적으로 재제조율이 낮은 부품인 범퍼, 도어, 펜더에 대해서 비용편익을 분석하였다. 분석 결과 각각 비용 편익은 제품별 개당 54,000원으로 발생하는 것으로 나타났고, 신제품의 50%를 재제조할 경우 매립비용의 절감으로 개당 226,060원의 이익이 발생하는 것으로 나타났다. 이와 같이 범퍼, 도어, 펜더를 재제조 했을 경우 상당한 편익이 발생하여 재제조업체의 충분한 경제성 확보가 가능할 것으로 판단된다.

• Tribology and Lubricants
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• 제31권1호
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• pp.13-20
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• 2015

The impact beam, a beam-shaped reinforcement installed horizontally between the inside and outside panels of car doors, is gaining importance as a solution to meet the regulations on side collision of vehicles. In order to minimize pelvis injury which is the biggest injury happening to the driver and passengers when a vehicle is subject to side collision, energy absorption at the door impact beam should be maximized. For the inner panel, the thrust into the inside of the vehicle must be minimized. The impact beam should be as light as possible so that the extent of pelvis injury to the driver and passenger during side collision of the vehicle is minimal. To achieve this, the weight of the impact beam, has to be optimized. In this study, we perform a design analysis with a goal to reduce the weight of the current impact design by 30% while ensuring stability, reliability, and comparison data of the impact beam for mass production. We conduct three-point bending stress experiments on conventional impact beams and analyze the results. In addition, we use a side-door collision test apparatus to test the performance of beams made of three (different materials: steel, aluminum, and composite beams).

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.95-96
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• 2015

This paper aims to identify patterns in users' requests for facility management (FM) services in higher education facilities. We analyzed data collected from 309 service request forms, made available via a department office and an enterprise resource planning system, at a private university in Seoul between May 2009 and February 2015. We found that the number of user requests were the highest in September and October. Requests for electronic and communication (E/C) services outnumbered those for architectural services and mechanical and plumbing (M/P) services. Repair requests for doors and windows were the most common under architectural services; repairs for air-conditioners and radiators were the most commonly under M/P services; and installation of electrical outlets, telephone wires, and internet services were the most sought-after E/C services. Maintenance requests were received every three months, while repair requests were received every six or seven months.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2003년도 춘계학술대회 논문집
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• pp.90-93
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• 2003

This study aims to validate the effectiveness of VE system with an arm-master in the evaluation of virtual prototype. A virtual kitchen with a refrigerator was presented in a CAVE system. Subjects put in and pull out virtual objects by using the arm-master. Twelve subjects participated in six experimental conditions: three types of refrigerator door grips and two reaction forces. After each trial, subjects evaluated a virtual refrigerator in terms of easiness of operation, similarity in force, presence etc. The results show the subjects preferred vertical grip than horizontal grip and light reaction force than heavy one. The VE system with the arm-master will be very helpful in the design evaluation of virtual prototypes.

• International Journal of Aeronautical and Space Sciences
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• 제4권2호
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• pp.79-87
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• 2003

Acoustic response control of a comer-pinned plate using piezoelectric wafers was studied, both theoretically and experimentally. Three different sizes of aluminum alloy plates were used and available ball joints were employed to hold the plate at the four comers. The plate with the largest aspect ratio showed the largest and most clear responses to the acoustic excitation in the range of frequencies (0~200Hz), and sound pressure levels (80~100dB) as predicted. The reduction of the acoustic response of the plate by piezoelectric actuator was very significant, more than expected, but abatement of the sound transmission through the plate was only slightly altered by the piezoelectric actuator. This work is an original work extending earlier work with doors excited by acoustic fields. The important difference is the used of ball joints to simulate the joints.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.421-428
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• 2004

Acoustic response control of a corner-pinned plate using piezoelectric wafers was studied, both theoretically and experimentally. Three different sizes of aluminum alloy plates were used and available ball joints were employed to hold the plate at the four corners. The plate with the largest aspect ratio showed the largest and most clear responses to the acoustic excitation in the range of frequencies (0～200Hz), and sound pressure levels (80～100dB) as predicted. The reduction of the acoustic response of the plate by piezoelectric actuator was very significant, more than expected, but abatement of the sound transmission through the plate was only slightly altered by the piezoelectric actuator. This work is an original work extending earlier work with doors excited by acoustic fields. The important difference is the used of ball joints to simulate the joints.

• 대한인간공학회지
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• 제6권2호
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• pp.9-18
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• 1987

The purpose of this study was to find the optimal stroke width-to-height ratio of the Korean character (Hangeul) which yields the greatest reading distance. In this study, black characters on a white background were used under 200 lux conditions in-doors, with the stroke width-to-height ratios ranging from a very thin 1:125 to heavier 1: 8.3. The criterion was the average reading distance at which three subjects (male university students) having normal visual acuity (1.2) could read the characters. Using the data obtained from the experi- ment, we analyzed the relationship between stroke width-to-height ratio and reading distance. In the case of the black characters on a white background, the greatest reading distances occurred with a range from 1:11.4 to 1:17.9.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2005년도 공동추계학술대회
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• pp.183-192
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• 2005

Recently, community computing has been proposed for group formation and group decision-making. However, legacy community computing systems do not support group need identification for ad hoc group formation, which would be one of key features of ubiquitous decision support systems and services. Hence, this paper aims to provide a multi-agent based methodology to enable nomadic community computing which supports ad hoc need identification and group formation. Focusing on supporting group decision-making of relatively small sized multiple individual in a community, the methodology copes with the following three characteristics: (1) ad hoc group formation, (2) context-aware group need identification, and (3) using mobile devices working in- and out-doors. NAMA-US, an RFID-based prototype system, has been developed to show the feasibility of the idea proposed in this paper.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.633-636
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• 2004

Acoustic response control of a corner-pinned plate using piezoelectric wafers was studied, both theoretically and experimentally. Three different sizes of aluminum alloy plates were used and available ball joints were employed to hold the plate at the four comers. The plate with the largest aspect ratio showed the largest and most clear responses to the acoustic excitation in the range of frequencies $(0\sim200Hz)$, and sound pressure levels $(80\sim100dB)$ as predicted. The reduction of the acoustic response of the plate by piezoelectric actuator was very significant, more than expected, but abatement of the sound transmission through the plate was only slightly altered by the piezoelectric actuator. This work is an original work extending earlier work with doors excited by acoustic fields. The important difference is the used of ball joints to simulate the joints.

• Journal of information and communication convergence engineering
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• 제19권3호
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• pp.161-165
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• 2021

Since the first commercialization of beacon-based services in 2011, various services have been provided to improve Bluetooth performance, and research has been conducted to accurately recognize user locations using beacons. The various measurement methods of indoor positioning systems (IPS) include methods using receiver signal strength indicator (RSSI) the strength of which varies greatly in accuracy depending on whether there are obstacles such as cement walls or doors. In this paper, we present a method to provide accurate positioning services even in the presence of obstacles in indoor spaces. To this end, we connect the HM-10 module supporting the beacon with Arduino Uno, to place beacons in three directions in real-world indoor space, and derive an optimal trilateration equation. Based on the derivation, we select the optimal expression for calculating the distance between the beacon and the moving station and use it to verify the coordinate determination for the moving station.