• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.609-614
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• 2008

The heating and cooling performance of system multi-air conditioner under high-head and long-line conditions are experimentally investigated. The maximum head and tube length were 110 m and 1000 m, respectively. The experimental system was composed of 4 outdoor units with module systems, and 13 indoor units which were joined with the mode change unit by single-tube circuit. Field tests without indoor and outdoor temperature control were performed in a general office building with 22 different working conditions. Experimental results were prepared on the p-h diagram. Also the oil level in the compressor was normally maintained at the safety zone for the system multi-air conditioner with high-head and long-line conditions.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.304-309
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• 2008

The heating and cooling performances of system multi-air conditioner for various refrigerant flow rates with high-head and long-line conditions are experimentally investigated. The maximum head and tube length were 110 m and 1000 m, and the two different adjustments of refrigerant flow rates were +20 % and -20 %, respectively. The experimental system was composed of 4 outdoor units with module systems, and 13 indoor units which were joined with the mode change unit by single-tube circuit. Field tests without indoor and outdoor temperature control were performed in a general office building with two different refrigerant flow rates. Especially, the oil level in the compressor was normally maintained at the safety zone. Experimental results were prepared on the p-h diagram.

• 센서학회지
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• 제31권6호
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• pp.433-440
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• 2022

Recently, owing to global warming, average summer temperatures are increasing and the number of hot days is increasing is increasing, which leads to an increase in heat stroke. In particular, outdoor workers directly exposed to the heat are at higher risk of heat stroke; therefore, preventing heat-related illnesses and managing safety have become important. Although various wearable devices have been developed to prevent heat stroke for outdoor workers, applying various sensors to the safety helmets that workers must wear is an excellent alternative. In this study, we developed a smart helmet that measures various vital signs of the wearer such as body temperature, heart rate, and sweat rate; external environmental signals such as temperature and humidity; and movement signals of the wearer such as roll and pitch angles. The smart helmet can acquire the various data by connecting with a smartphone application. Environmental data can check the status of heat wave advisory, and the individual vital signs can monitor the health of workers. In addition, we developed an algorithm that classifies the risk of heat-related illness as normal and abnormal by inputting a set of vital signs of the wearer using a support vector machine technique, which is a machine learning technique that allows for rapid binary classification with high reliability. Furthermore, the classified results suggest that the safety manager can supervise the prevention of heat stroke by receiving feedback from the control system.

• 한국환경복원기술학회지
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• 제19권4호
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• pp.1-17
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• 2016

In this study, remodeling projects are perceived as a sustainable urban management policy to boost the value of old apartments and stimulate urban regeneration and development. To evaluate the physical environmental performance of external spaces of remodeled apartments, an evaluation model was developed. After applying it to the target places, the following results were obtained. First, analysis of the external space change index of the target apartments revealed that institutional standards are necessary in line with the building arrangement type, parking lot expansion method, and changes in the building-to-land ratio. Second, the score ratio as to the external space change index performance is as follows: safety (48.30); pleasantness (25.90); convenience (18.90); eco-friendliness (14.90). In other words, "safety" had the biggest score ratio. Third, to boost the external space performance of remodeled apartments, the needs of residents and neighboring environmental plans should be considered from a communality standpoint.

• 산업경영시스템학회지
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• 제38권4호
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• pp.226-232
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• 2015

The aging of Korea is rapidly advancing in an unprecedented rate in the world. Indoor and outdoor safety accidents involving the elderly frequently occur, with elderly population increasing. Because the physical strength of elderly is decreased, it is necessary to develop devices that aid the everyday life of the elderly to prevent safety accidents. Among many activities, the motions of standing from and sitting on a chair require much physical strength from particular body parts, which causes an overload for particular body parts. To the elderly the repeating motion of standing from and sitting down on a chair is burdensome, because they do not have enough physical strength compare to young persons. As a result the elderly could be injured or falling during standing or sitting. Therefore, the development of a lift chair that considers the problems mentioned above is necessary to prevent the safety accidents of the elderly. The study designed a non-motorized lift chair that comfortably aids the standing and sitting down motion for the use of the elderly by reflecting the anthropometric data of the Korean elderly over 65 years old. Also the design was implemented to smoothly aid the standing motion by considering the knee angle of the elderly when standing. Because the regained strength to stand from a chair is depend on the knee angle. Unlike existing lift devices, this device utilizes a tilting mechanism that does not use electric power so that the product could be composed inexpensively than existing chairs released in the market.

• 한국산업보건학회지
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• 제22권4호
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• pp.284-292
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• 2012

Objectives: The objective of this study was to investigate the relations between the bacterial concentration and the environmental factors in the water soluble metal working fluids at factories. Methods: The bacterial concentrations for airborne and fluid samples of 7 factories were quantified during the summer season. And we statistically analysed the relations between the bacterial concentrations and the factors such as temperature, relative humidity, usage quantity, mixing ratio and exchange interval. Results: The geometric mean levels of the airborne bacterial concentrations were 79.1(range : N.D.~686) $CFU/m^{3}$ and 68.1(range: N.D.~919) $CFU/m^{3}$ in the process and outdoor. The airborne bacterial concentrations showed no statistical difference by process, usage quantity, mixing ratio and exchange interval. The airborne bacterial concentrations had negatively weak correlations with air temperature and relative air humidity(p<0.05). The bacterial concentrations and pH showed significantly negative correlations in the fluids(p<0.05). And the airborne bacterial concentrations in factories and those in metal working fluids showed no statistical relationship. Conclusions: In the water soluble metal working fluids using factories, the airborne bacterial concentrations of the process were related to those of the outdoor and environmental factors, rather than the onsite contaminated metal working fluids.

• 한국가스학회지
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• 제20권6호
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• pp.73-79
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• 2016

이동형 LP가스 사용시설은 야외에서 임시적으로 구성 및 사용되는 LP가스 시설로서 국내 지역축제 등에 설치되는 천막, 포장마차 등의 LP가스 시설을 의미한다. 이러한 이동형 LP가스 시설은 법정검사 대상이 아니기 때문에 안전관리의 주체 또는 방법이 모호하여 효과적인 안전관리를 위한 방안이 필요하다. 본 연구에서는 국내에서 개최되는 지역축제 및 포장마차 등의 실태조사 및 위험요소 분석을 통해 안전관리 개선 방안의 방향성을 살펴보고 금속배관의 사용, 공동 용기보관 등의 개선방안을 제시하고자 하였다. 본 연구의 결과를 통해 국내 이동형 LP가스 사용시설의 안전 관리 효율성 증대에 도움이 될 수 있을 것으로 기대한다.

• 한국조경학회지
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• 제52권1호
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• pp.34-45
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• 2024

반려견이 사회의 일원으로 인식되기 시작하면서 도시의 옥외 공공공간을 함께 이용하는 주체로 부상하고 있다. 그러나 이러한 흐름은 위생, 소음 등의 문제를 발생시키거나 반려인과 비반려인 간 갈등을 야기하는 요인이 되기도 한다. 본 연구는 '반려견', '반려동물', '강아지'와 관련된 공개민원 자료를 텍스트마이닝 기법을 통해 분석하여, 반려견 관련 공간갈등의 원인과 주요 이슈를 밝히기 위해 수행되었다. 연구의 주요 결과는 다음과 같다. 첫째, 반려견과 관련된 민원자료 중 대다수는 옥외 공공공간의 이용과 연관이 있었다. 둘째, 주요 옥외 공공공간 유형별로 공간의 이슈가 다르게 발생하고 있다. 셋째, 반려견 관련 민원자료의 주제는 총 4개로, '반려견 놀이터 조성 요구', '동물 관련 안전 문제 제기', '반려견 전용구역 외 시설에 대한 이용 문제 제기', '펫티켓 관련 공원 관리·단속 강화 요청'이다. 본 연구는 동물이 이용할 수 있는 공공공간의 범위가 확대되는 시점에서, 반려견을 둘러싼 시민들의 인식을 분석했다. 특히, 시민들이 문제점과 요구사항을 명확하게 제시하는 민원자료를 분석 대상으로 채택함으로써, 시민들의 의견을 수렴하는 새로운 방식을 적용한 점에서 의의가 있다.

• 제어로봇시스템학회논문지
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• 제19권11호
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• pp.1017-1021
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• 2013

The traffic signal has been widely used in the transport system with a fixed time interval currently. This kind of setting time was determined based on experience for vehicles to generate a waiting time while allowing pedestrians crossing the street. However, this strict setting causes inefficient problems in terms of economic and safety crossing. In this research, we propose a monitoring algorithm to detect, track and check pedestrian crossing the crosswalk by the patterns of behavior. This monitoring system ensures the safety for pedestrian and keeps the traffic flow in efficient. In this algorithm, pedestrians are detected by using HOG feature which is robust to illumination changes in outdoor environment. According to a complex computation, the parallel process with the GPU as well as CPU is adopted for real-time processing. Therefore, pedestrians are tracked by the relationship of hue channel in image sequence according to the predefined pedestrian zone. Finally, the system checks the pedestrians' crossing on the crosswalk by its HOG based behavior patterns. In experiments, the parallel processing by both GPU and CPU was performed so that the result reaches 16 FPS (Frame Per Second). The accuracy of detection and tracking was 93.7% and 91.2%, respectively.

• Journal of Computational Design and Engineering
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• 제3권3호
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• pp.250-265
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• 2016

Owing to our rapidly aging society, accessibility evaluation to enhance the ease and safety of access to indoor and outdoor environments for the elderly and disabled is increasing in importance. Accessibility must be assessed not only from the general standard aspect but also in terms of physical and cognitive friendliness for users of different ages, genders, and abilities. Meanwhile, human behavior simulation has been progressing in the areas of crowd behavior analysis and emergency evacuation planning. However, in human behavior simulation, environment models represent only "as-planned" situations. In addition, a pedestrian model cannot generate the detailed articulated movements of various people of different ages and genders in the simulation. Therefore, the final goal of this research was to develop a virtual accessibility evaluation by combining realistic human behavior simulation using a digital human model (DHM) with "as-is" environment models. To achieve this goal, we developed an algorithm for generating human-like DHM walking motions, adapting its strides, turning angles, and footprints to laser-scanned 3D as-is environments including slopes and stairs. The DHM motion was generated based only on a motion-capture (MoCap) data for flat walking. Our implementation constructed as-is 3D environment models from laser-scanned point clouds of real environments and enabled a DHM to walk autonomously in various environment models. The difference in joint angles between the DHM and MoCap data was evaluated. Demonstrations of our environment modeling and walking simulation in indoor and outdoor environments including corridors, slopes, and stairs are illustrated in this study.