• 재활복지공학회논문지
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• 제7권2호
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• pp.109-115
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• 2013

본 논문에서는 전동휠체어용 압력분포 측정시스템을 개발하고, 실제 휠체어 사용자들을 대상으로 동작분석과 연계한 압력분포 변화실험을 통해 유의성을 검증하고자 하였다. 측정시스템은 휠체어 이동방향에 따른 압력분포 변화 측정을 위해 64ch의 시트쿠션 FSR 센서신호 및 좌 우 각 30ch의 팔걸이 FSR 센서신호를 2ch의 좌 우 바퀴형 엔코더 신호와 동시에 12bit, 10Hz의 샘플링 속도로 획득할 수 있도록 개발하였으며, 이 신호들을 USB 인터페이스를 통해 휠체어 뒤쪽에 장착 가능한 노트북PC로 전송 후 실시간으로 화면표시, 저장, 재생을 수행할 수 있는 실시간 신호처리 소프트웨어를 개발하였다. 개발된 측정시스템을 사용한 압력분포 변화 실험은 실제 휠체어 사용자 10인을 대상으로 적외선 마커 기반의 동작분석실에서 3D 동작분석과 연계하여 실시하였다. 실험결과, 휠체어 진행 중 회전구간에서 몸이 회전의 바깥 방향으로 기울어지는 것을 확인할 수 있었으며 실험결과 및 실험 후 인터뷰를 통해 전동휠체어 설계 시 시트의 형태에 대한 개선요구사항을 획득할 수 있었다.

• 전기화학회지
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• 제5권1호
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• pp.27-29
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• 2002

본 연구는 메탄올과 공기를 이용하여 상온, 상압에서 전기를 발생시키는 휴대폰용 전원공급 장치의 개발에 관한 것이다. 이 장치는 직접 메탄을 연료전지(DMFC)와 Back-up전지가 병렬로 연결되어 있어, 통화시 소요 전력의 최대 $50\%$ DMFC가 공급하고 나머지 부분은 Back-up 전지가 공급한다. 또한 통화 대기시에는 DMFC가 $100\%$ 필요 전력을 공급하고, 잉여 전력으로 Back-up전지를 충전한다. 상기 DMFC는 유효면적이 $9cm^2$인 8개의 단위전지가 직렬로 연결되어 있으며, 휴대폰의 작동 전압 범위인 2.5-3.9V의 전압을 출력한다.

• 한국건설관리학회논문집
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• 제1권3호
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• pp.75-80
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• 2000

공간의 분할이 많은 건축공사에서는 반복적 특성으로 인해 공정계획상에 다수의 대안이 존재한다. 공사기간은 각 액티비티의 기간뿐 아니라 반복되는 액티비티의 배열방법에 의해서도 많은 영향을 받는다. 본 연구는 각 액티비티에 적정한 선행 액티비티를 할당함으로써 여유시간을 최소화하는 공정계획기법을 제시하는 것을 목적으로 진행되었다. Line of Balance 기법을 기본으로 하는 기존연구와는 달리 본 연구에서는 AON방식의 네트워크 기법을 기본으로 하여 공간과 자원의 두 축 사이에 액티비티를 배열하였다. 각 액티비티별로 자원과 공간의 양방향으로 가장 적절한 선행 액티비티를 검색하여 여유시간을 최소화한다. 본 연구에서 제시한 액티비티 배열방법을 공동주택공사 건설공사를 대상으로 적용한 결과, 액티비티 배열을 달리함에 따라서 다수의 대안이 존재함을 확인할 수 있었으며 그중 적정대안을 찾아낼 수 있었다. 본 기법은 공동주택공사와 같은 다수의 유사공간으로 구성된 건설공사의 공정 계획에 도움을 줄 수 있을 것으로 판단된다.

• Journal of Advanced Marine Engineering and Technology
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• 제37권6호
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• pp.638-643
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• 2013

유압시스템의 출력밀도를 높이기 위해 고압화, 대형화 되고 있으나, 유압동력 발생장치(HPU)를 구동할 때 110 dB(A) 정도의 높은 소음이 발생한다. 최근 산업안전규제 강화와 작업장 환경개선 요구 등으로 인하여 HPU의 소음저감을 위한 방안으로 실외나, 지하에 별도의 설치공간을 만들어 HPU를 이용하는 경우가 있었으나, 배관에서의 작동유 유동마찰로 인한 동력손실과 고장 났을 때 신속하게 대응하는데 문제가 있었다. 본 연구에서는 HPU의 동력변환 과정에서 필수적으로 발생되는 소음을 효과적으로 차폐시키면서 동력손실을 저감시키는 방음챔버(chamber)를 채용하여 소음특성을 개선하는 연구를 실험적으로 하였다.

• Tribology and Lubricants
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• 제21권6호
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• pp.268-271
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• 2005

In this study, the wear characteristics of five different dental composite resins cured by conventional halogen light and LED light sources were investigated. Five different dental composite resins of Surefil, Z100, Dyract AP, Fuji II LC and Compoglass were worn against a zirconia ceramic ball using a pin-on-disk type wear tester with 15N contact force in a reciprocal sliding motion of sliding distance of 10mm/cycle at 1Hz under the room temperature dry condition. The wear variations of dental composite resins were linearly increased as the number of cycles increased. It was observed that the wear resistances of these specimens were in the order of Dyract AP > Surefil > Compoglass > Z100 > Fuji II LC. On the morphological observations by SEM, the large crack formation on the sliding track of Fuji II LC specimen was the greatest among all resin composites. Dyract AP showed less wear with few surface damage. There is no significant difference in wear performance between conventional halogen light curing and light emitting diodes curing sources. It indicates that a light emitting diodes (LED) source can replace a halogen light source as curing unit for composite resin restorations.

• 한국농촌건축학회논문집
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• 제2권1호
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• pp.13-24
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• 2000

This study aims at revealing important utilization planning by surveying and analyzing unused classrooms in primary school's facilities. That is various and positive utilization planning of unused classrooms in order to cope with the changes of educational environment focused on high and multi-functionization, rather qualitative aspect than quantitative. By field-survey and interview, physical and environmental factors such as, the change procedure of students, unused facilities in schools and improvement affairs and purpose stressed by schools were surveyed. Additionally, the way of educational facilities to future society linked with residents was examined by surveying about the relationship between educational facilities and regional communities. The curriculums and "School facilities standard ordinance" have been revised in part by several times individually and couldn't meet with educational facilities, educational and social change positively. In rural area, to apply the standard of the capacity by a class with 40 students like city is not desirable. To make educational environment better qualitatively, the capacity should be reduced by 30 students and the unit square per a student enlarged by $2.4m^2$. By room unit module "school institution and managerial regulations under high school" should be applied distinctively to break down like 6, 7~12, 13~24 and over 25 classes. So re-institution of the capacity by a class and the standard unit of the number of class by scale is needed.

• Perspectives in Nursing Science
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• 제15권1호
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• pp.18-28
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• 2018

Purpose: This study was designed to explore the levels of physical activity and fatigue among nurses and to identify the relationship between these variables. Methods: Participants were 89 nurses working at an intensive care unit and an operating room in a children's hospital. Data were collected using self-reported questionnaires including the International Physical Activity Questionnaire and Brief Fatigue Inventory. Results: Most of the nurses' physical activity was work related, and there was a significant difference according to the working unit. Nurses with higher work stress and lower job satisfaction showed higher levels of fatigue than their counterparts did. Work-related physical activity and the interference of fatigue with relationships were related positively, whereas transport and leisure time physical activity were negatively related to usual fatigue and the interference of fatigue with life enjoyment. Conclusion: The levels of physical activity and fatigue of nurses were higher than those observed among other populations. The appropriate level of physical activity for these nurses needs to be investigated carefully. Also, in the intervention for nurses' fatigue, their level of work-related and leisure-time physical activity should be considered separately, and their work environment and psychological satisfaction level should be included.

• 디지털융복합연구
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• 제11권4호
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• pp.243-249
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• 2013

본 논문에서는 GPS(Global Positioning System)를 사용할 수 있는 실외와 GPS(Global Positioning System)를 사용할 수 없는 실내에서 Wi-Fi(Wireless Fidelity)를 이용한 안드로이드 기반의 위치 정보 시스템을 설계 및 구현하였다. 보행자의 위치를 실내에서 추정하기 위해서는, 보행자의 위치에 상관없이 절대위치를 구하는 것이 필요하고, 보행자의 움직임에 따라서 상대위치를 연속적으로 추정하는 것이 필요하다. 보행자의 초기위치를 추정하기 위해서 Wi-Fi fingerprinting을 사용하였다. 기존의 Wi-Fi fingerprinting에서 가장 위치 오차가 작은 WKNN(Weighted K Nearest Neighbor) 알고리즘의 단점을 보완한 EWKNN(Enhanced Weighted K Nearest Neighbor) 알고리즘을 사용해 위치의 정확도를 높였다. 그리고 보행자의 상대위치를 추정하기 위해서는, 스마트폰에 탑재되어 있는 IMU(Inertial Measurement Unit)를 사용하였기 때문에 추가적인 장비가 필요하지 않았다.

• 한국입자에어로졸학회지
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• 제9권3호
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• pp.139-147
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• 2013

The performances of indoor air cleaners including particle cleaning capacity and collection efficiency are usually tested at the condition of the maximum air flow rate of the air cleaners. However, the power consumption of the air cleaners is highly dependent on the air flow rate of the individual air cleaners. Therefore, there seems to be an optimized air flow rate for the air cleaning capacity considering power consumption. In this study, clean air delivery rate(or standard useful area as suggested room size) and power consumption have been investigated for different maximum air flow rates of 15 air cleaners and then compared those for different air flow rate modes of the individual 5 air cleaners selected from the 15 cleaners. For the maximum air flow rate conditions of 15 air cleansers, the power consumption per unit area was less related to the maximum air flow rate. However, for the different air flow rate modes of the selected 5 air cleaners, the lower power consumption per unit area was corresponding to the lower air flow rate mode of the individual air cleaners. When considering the operation time to the desired particle concentrations, there was an optimized one in the medium air flow rate modes for the individual air cleaners. Therefore, not only the maximum air flow rate but also lower air flow rates of individual air cleaners should be considered for estimating air cleaning capacity based on energy consumption per unit area.

• 한국주거학회논문집
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• 제20권3호
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• pp.1-10
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• 2009

The final aim of this study was to propose guidelines for the indoor environment of apartment remodeling projects. The first task of this study was to understand the major elements and the actual condition of the remodeling for apartment unit by carrying out in-depth interviews on residents and specialists. The open-access interviews were conducted with interior designers who have a wide experience of apartment remodeling and residents who live in recently remodeled apartment units. The second task was to evaluate the actual condition of the indoor environment and to analyze the main factors that affect the indoor environment in remodeled apartment units. Field measurements were carried out in twenty apartment units occupied after remodeling, recording indoor environment elements (indoor temperature, globe temperature, relative humidity, $CO_2$, CO, PM10, TVOC, HCHO, illumination, and equivalent noise level). Moreover, resident interviews and researcher observations were carried out to determine the contents of the remodeled unit and to investigate the architectural and living factors(like ventilation characteristics, etc.) related to the indoor environment. The results are as follows. The remodeling elements generally included the changing of lighting fixtures and finishing materials in all the spaces, the integration of the balcony into the children's room, the installation of furniture in the kitchen and the entrance, the changing storage furnitures and equipments in the bathroom. The average levels of each unit of relative humidity, $CO_2$, TVOC, HCHO, equivalent noise level, and illumination were proved to be on the whole in inadequate condition. The factors that affect these indoor elements were classified as remodeling factors (remodeling amounts, extent balcony integration, and lighting fixture exchange), ventilation characteristics, and living factors. According to these results, this research proposed the guidelines for the indoor environment in apartment remodeling projects.