• Title/Summary/Keyword: Indoor noise

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Landmark Recognition Method based on Geometric Invariant Vectors (기하학적 불변벡터기반 랜드마크 인식방법)

  • Cha Jeong-Hee
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.3 s.35
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    • pp.173-182
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    • 2005
  • In this paper, we propose a landmark recognition method which is irrelevant to the camera viewpoint on the navigation for localization. Features in previous research is variable to camera viewpoint, therefore due to the wealth of information, extraction of visual landmarks for positioning is not an easy task. The proposed method in this paper, has the three following stages; first, extraction of features, second, learning and recognition, third, matching. In the feature extraction stage, we set the interest areas of the image. where we extract the corner points. And then, we extract features more accurate and resistant to noise through statistical analysis of a small eigenvalue. In learning and recognition stage, we form robust feature models by testing whether the feature model consisted of five corner points is an invariant feature irrelevant to viewpoint. In the matching stage, we reduce time complexity and find correspondence accurately by matching method using similarity evaluation function and Graham search method. In the experiments, we compare and analyse the proposed method with existing methods by using various indoor images to demonstrate the superiority of the proposed methods.

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How do they Make Libraries Green?: A Case Based Study on Building Green Libraries (녹색도서관 사례분석을 기반으로 한 국내 녹색도서관 구축방향에 관한 연구)

  • Ahn, In-Ja;Kwak, Chul-Wan;Noh, Young-Hee;Park, Mi-Young
    • Journal of Information Management
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    • v.43 no.1
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    • pp.135-158
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    • 2012
  • Since the 1990s, discussions regarding green libraries started in the U.S.A, in the name of 'library and the environment', 'Green librarians', 'constructing of environmental sources', 'noise and library', 'building libraries as an environmental alternative' and etc. Currently, green libraries certified by an evaluation system are more than 50. This study proposes a direction to build a green library. The study analyzes national and international green libraries certified by the evaluation system. The cases are analyzed based on the six evaluation factors in the LEED certification system; Sustainable Site, Water Efficiency, Energy and Atmosphere, Material and Resources, Indoor Environmental Quality, Innovation and Design Process. Since the evaluation system focuses mainly on the architectural aspects, there was a need of expanding the concept of eco-friendly in this research. The newly expanded eco-friendly concept includes services, content, and supplies of libraries.

Current Interior Design and User Preference for Child Care Facilities - Focused on Interior Atmosphere, Finishing Materials and Colors - (보육시설 실내디자인 현황과 사용자 선호성향 - 실내분위기, 마감재, 색채를 중심으로 -)

  • Ha, Sook-Nyung;Chun, Jin-Hie
    • Korean Institute of Interior Design Journal
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    • v.17 no.3
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    • pp.111-122
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    • 2008
  • As Korea has undergone rapid modernization, urbanization and industrialization, women's social participation has increased. Accordingly, child care facilities have shown continuous growth in numbers. However, according to research, child care facilities in Korea lag behind those in other nations in terms of quality. Given that, it seem urgent to enhance the quality of child care facilities and improve their indoor environment. Above all, overall atmosphere, colors and finishing materials are connected directly with educational effects as well as feelings and health of facility users. This study assesses the current state of child care facilities and preferences by focusing primarily on interior atmosphere, materials and colors. For This Study, 7 facilities were surveyed, and 46 subjects were participated for this study. The findings suggest that "pretty" style is preferred to "natural" style. As regards flooring material, wood floor is preferred. It is recommended to lay pastel colored carpet or PVC flooring material to the wood floor. As for wall, it is desirable to divide the wall spaces by adding wood and painting to simple wallpapers. In case of the ceiling noise absorptive material is recommended to use instead of wallpapers. For the doors, it is desirable to use contrasting materials and colors given accessibility for children. In the meantime, rather than strong primary colors, soft color or pastel colors are desirable for furniture. This study has limitations because of insufficiency of case study samples. However, it is significant in that the study results may be used as primary source of information to improve the environment of child care facilities.

A Study on The Performance of Ventilation and Maintaining Thermal Environment for a Combined Type Diffuser (급·배기 일체형 디퓨저의 환기 및 온열환경 유지성능에 대한 연구)

  • Lim, Seok-Young;Chang, Hyun-Jae
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.28 no.6
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    • pp.232-241
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    • 2016
  • Installing a ventilator for an apartment house composed of over 100 dwelling units was mandated in 2006 to improve indoor air quality. In the case of mechanical ventilators, the air change rate is kept stable, however 68% of dwellers do not operate their ventilator because of an increased electrical bill and noise. In the case of natural ventilators, the former problems are settled, but there are concerns about cold draught and an increase of heating/cooling cost. Authors are developing a heat recovery type natural ventilator which is a natural ventilator equipped with total heat recovery element, and it is expected that those problems of mechanical ventilator and natural ventilator are resolved by this. The combined type diffuser of this study is an under developed fit to the heat recovery type natural ventilator above. There are no standards to evaluate the performance for this type of diffuser. Due to this issue this study investigated the performance of the ventilation and maintained a thermal environment for the combined type diffuser by comparing it with existing diffusers. The results revealed that the performances of the combined type of diffusers showed different features from the existing ones, and was estimated to be high enough in the performances above.

Performance of hybrid modulation for digital IoT doorlock system with color grid (컬러그리드기반 디지털 IoT 도어락 시스템을 위한 혼합변조의 성능)

  • Lee, Sun-Yui;Sun, Young-Ghyu;Sim, Issac;Hwang, Yu-Min;Yoon, Sung-Hoon;Cha, Jae-Sang;Kim, Jin-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.6
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    • pp.91-97
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    • 2018
  • This paper presents implementation possibilities of digital IoT doorlock systems via VLC(Visible Light Communication)'s color grid. The color grid-based VLC modulation scheme which are discussed in this paper utilize the straightness of light and abundant frequency resources which are the properties of the light. Performance results in this paper are compared to that of conventional modulations with Bit Error Rate (BER) and Signal to Noise Ratio (SNR) simulations. With respect to a channel model, the proposed modulation schemes select the nearest Line Of Sight (LOS) except Non Line Of Sight (NLOS). Experiments in this paper show error rates of received symbols by changing power dB at a distance of 3m between Tx and Rx in an indoor environment. Through performance results and experiments, this paper demonstrates superiority of the proposed color grid-based modulation schemes.

Real-Time Change Detection Architecture Based on SOM for Video Surveillance Systems (영상 감시시스템을 위한 SOM 기반 실시간 변화 감지 기법)

  • Kim, Jongwon;Cho, Jeongho
    • The Journal of Korean Institute of Information Technology
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    • v.17 no.4
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    • pp.109-117
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    • 2019
  • In modern society, due to various accidents and crime threats committed to an unspecified number of people, individual security awareness is increasing throughout society and various surveillance techniques are being actively studied. Still, there is a decline in robustness due to many problems, requiring higher reliability monitoring techniques. Thus, this paper suggests a real-time change detection technique to complement the low robustness problem in various environments and dynamic/static change detection and to solve the cost efficiency problem. We used the Self-Organizing Map (SOM) applied as a data clustering technique to implement change detection, and we were able to confirm the superiority of noise robustness and abnormal detection judgment compared to the detection technique applied to the existing image surveillance system through simulation in the indoor office environment.

A Study on the Analysis of Environmental Hazards when Dismantling Non-Structure of Old Residential Buildings (노후 주거용 건축물 비구조체 해체 시 환경유해인자 분석)

  • Son, Byeung-Hun
    • Journal of Urban Science
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    • v.10 no.1
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    • pp.29-37
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    • 2021
  • The number of old buildings older than 30 years in Korea continues to increase from 29.9% in 2005 to 38.8% in 2020. Considering the growing urban regeneration projects, urban maintenance projects, the suppression of urban expansion, and the lack of idle land in the city, the dismantling of old buildings is expected to increase further in the future. As major accidents at building dismantling sites continue to occur, related agencies are also strengthening safety management of building dismantling works. While physical safety management such as collapse and fall is strengthened, there is a relative lack of interest in the health of workers at dismantling sites due to environmental hazards. Since relevant laws stipulate that construction waste should be separated and discharged, old buildings need to be considered for environmental hazards such as fine dust, floating bacteria, and floating molds when dismantling. In this study, we intend to find important safety management elements in the management of building dismantling sites, measure environmental factors harmful to dismantling workers, and present basic data for the management of dismantling sites in the future. "Safety management" was the highest priority, followed by "dust," "vibration," "noise," "bacteria," and "smell." The perception of the importance of "physical damage prevention" with workers working on dismantling and managers managing the site came out similar, but the perception of "work efficiency" and "health disorder prevention" through environmental hazard management showed different priorities. In the process of dismantling, floating bacteria and floating mold were collected, cultured, and measured the concentration in the indoor air. The measurement was measured by dividing it into pre-dismantling and during dismantling.

Positioning-error Analysis of Vibration Sensors for Prognostics and Health Management in Rotating System (갠트리 크레인 호이스트의 건전성 평가를 위한 진동 모사시스템 구축과 데이터 통계 분석)

  • Jang, Jaewon;Han, Zhiqiang;Zhang, Haiyang;Oh, Daekyun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.2
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    • pp.346-353
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    • 2022
  • Recently, studies on the integrity of rotating machines, such as gantry cranes, which are used in the shipbuilding industry, have been actively conducted. Gantry cranes are driven at relatively low revolutions per minute (RPM), are frequently operated and stopped, and are impacted by external environmental factors, such as shock and noise in the measurement data. The purpose of this study was to construct a replica of a gantry crane hoist used in indoor shipbuilding and analyze the acquired data for errors caused by the shift in operating conditions (RPM) and the change in the position of the data acquisition sensor. Consequently, we observed that the error caused by differences in sensor positions did not occur significantly under low operating conditions but occurred significantly under relatively high operating conditions. Thus, we determined that both the operating condition and position of the acquisition sensor affected the data acquired by the rotary machine.

Investigations on the emergency operation status of existing medical facilities to prepare for emerging infectious diseases in the post-COVID-19 era (포스트 코로나 시대 신종 감염병 대비를 위한 기존 의료시설의 비상시 운영사례 조사 및 분석)

  • Lee, Sejin;Lee, Wonseok;Kim, Eunseok;Yeo, Myoungsouk
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.29 no.1
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    • pp.43-51
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    • 2023
  • Purpose: To accommodate the increasing number of patients during the COVID-19 pandemic, numerous portable HEPA filter units (PHUs) were installed in the general wards of existing medical facilities(EMFs) to convert them into emergency conversion facilities (ECFs). The purpose of this study was to build a dataset in preparation for emerging infectious diseases in the post-COVID-19 era by analyzing the construction and operation of ECFs. Methods: Field investigations were conducted during ECF operation periods based on the analysis of heating, ventilation, and air conditioning (HAVC) system design documents for six ECFs across Korea. Interviews were conducted with facility managers during the field investigations. Results: When constructing an ECF within an EMF, the installation status and characteristics of the existing system should be considered. Field investigations and verifications of the operation of HAVC systems must be conducted beforehand for smooth ECF operations. If heating and cooling are required with indoor air circulation type equipment in an ECF zone, the implementation of a heating and cooling method that can satisfy the comfort requirements of the occupants while minimizing cross-contamination is essential. When using PHUs that do not meet the performance standards required by medical equipment, the noise level resulting from such equipment operation must be evaluated and improved. Implications: For EMFs, various guidelines that can be referred to for the construction and operation of ECFs must be developed to prepare for emerging infectious diseases in the future.

Impact of Indoor Green in Rest Space on Fatigue Recovery Among Manufacturing Workers (휴게공간에서의 식물 도입이 생산직 근로자의 피로 회복에 미치는 효과)

  • ChoHye Youn;LeeBom Chung;Minji Kang;Juyoung Lee
    • Journal of Environmental Science International
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    • v.33 no.3
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    • pp.217-226
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    • 2024
  • Manufacturing workers face increased fatigue and stress due to environmental factors in workplace such as noise and vibration. Addressing this issue requires creating conducive rest spaces; however, the existing conditions of rest spaces in manufacturing workplace are subpar and lack sufficient scholarly evidence. This study investigated the effect of nature-based rest spaces on the physical and emotional recovery from fatigue on manufacturing workers. Three manufacturing complexes with nature-friendly rest spaces were selected, and 63 manufacturing workers participated in the study. The measurement tools included the Multidimensional Fatigue Scale (MFS) for fatigue levels, physiological indicators (blood pressure and heart rate), and emotional indicators (Zuckerman Inventory of Personal Reaction Scale; ZIPERS, Perceived Restorativeness Scale; PRS, Profile of Mood States; POMS and State-Trait Anxiety Inventory; STAI). The study compared recovery levels during a 7-minute rest between a space without plants and a space with natural elements. The results indicated a significant reduction in systolic and diastolic blood pressure of participants in green rest spaces compared with those in conventional rest spaces. Regarding fatigue levels, green rest spaces showed a decrease in systolic blood pressure in the middle-fatigue and high-fatigue groups. Positive feelings increased in green spaces, whereas negative emotions decreased, suggesting that short breaks in nature-friendly environments effectively promote workers' physical and emotional recovery. Furthermore, this study emphasizes the importance of green space in various work environments to promote well-being in workers.