• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.814-819
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• 2005

There is growing consciousness of the environmental performance of buildings in Hong Kong. The Buildings Department, the Lands Department and the Planning Department of the Hong Kong Government issued the first of a series of joint practice notes [1] to promote the construction of green and innovative buildings. Green features are architectural features used to mitigate migration of noise and various air-borne pollutants and to moderate the transport of heat, air and transmission of daylight from outside to indoor environment in an advantageous way. This joint practice note sets out the incentives to encourage the industry in Hong Kong to incorporate the use of green features in building development. The use of green features in building design not only improves the environmental quality, but also reduces the consumption of non-renewable energy used in active control of indoor environment. Larger window openings in the walls of a building may provide better natural ventilation. However, it also increases the penetration of direct solar radiation into indoor environment. The use of wing wall, one of the green features, is an alternative to create effective natural ventilation. This paper therefore presents a preliminary numerical study of its ventilation performance using Computational Fluid Dynamics (CFD). The numerical results will be compared with the results of the wind tunnel experiments of Givoni.

• 전기전자학회논문지
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• 제27권4호
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• pp.439-449
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• 2023

In an era marked by the increasing use of drones and the growing demand for indoor surveillance, the development of a robust application for detecting and tracking both drones and humans within indoor spaces becomes imperative. This study presents an innovative application that uses FMCW radar to detect human and drone motions from the cloud point. At the outset, the DBSCAN (Density-based Spatial Clustering of Applications with Noise) algorithm is utilized to categorize cloud points into distinct groups, each representing the objects present in the tracking area. Notably, this algorithm demonstrates remarkable efficiency, particularly in clustering drone point clouds, achieving an impressive accuracy of up to 92.8%. Subsequently, the clusters are discerned and classified into either humans or drones by employing a deep learning model. A trio of models, including Deep Neural Network (DNN), Residual Network (ResNet), and Long Short-Term Memory (LSTM), are applied, and the outcomes reveal that the ResNet model achieves the highest accuracy. It attains an impressive 98.62% accuracy for identifying drone clusters and a noteworthy 96.75% accuracy for human clusters.

• 토지주택연구
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• 제13권3호
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• pp.107-113
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• 2022

건축물의 에너지소비를 줄이기 위해 건물의 기밀도가 지속적으로 향상되고 있으며, 이로 인해 건물 내부의 평균적인 상대습도가 높아지고 있다. 평균 상대습도가 높아짐에 따라 단열 취약부 및 습기발생 행위 시 결로가 발생하며, 습기제어를 위하여 기계 환기장치의 중요성이 향상되고 있다. 그러나, 기계환기장치는 추가적인 에너지 소비 및 소음 발생으로 재실자의 불쾌감을 유발하기 때문에, 서로 상충되는 기준에 대한 적절한 환기전략 선정이 필요하다. 본 연구에서는 공동주택 내 기계환기장치의 환기성능, 에너지 소비량, 소음도를 측정하여, 서로 상충하는 운영기준 중 우선순위에 있는 환기전략을 찾기위해 다기준 의사결정기법인 TOPSIS를 이용하였다. 또한, 재실자의 환기장치 운영기준 선호도에 따라 달라지는 적절 환기전략을 도출하였으며, 향후 AI 기술을 활용한 재실자 맞춤 환기전략 제시가 가능할 것으로 사료된다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.289-294
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• 2002

In this study, performance, flow characteristics and noise of a cross-flow-fan system, used in indoor unit of the split-type air conditioner, were predicted by computational simulation. Triangular elements were used to mesh the calculation domain and quadrilateral elements were attached to the blade surfaces and walls to enhance the simulation quality. The unsteady incompressible Wavier-Stokes equations were solved using a sliding mesh technique on the interface between rotating fan region and the outside. Two stripes of velocity stream inside the cross-flow-fan were shown - the one was due to the eccentric vortex and the other was due to the normal entrance flow. As the flow rate increased, the center of the eccentric vortex moved toward the inner blade tip and rear-guide, and the exiting flow still had velocity variation along the stabilizer, which can increase the noise level. The acoustic pressure was calculated by using Lowson's equation. From the calculated acoustic pressure, it was found that the trailing edge is a dominant of acoustic generation.

• International Journal of Internet, Broadcasting and Communication
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• 제13권4호
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• pp.11-21
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• 2021

The causes of noise generation according to the classification of indoor spaces are very diverse. Individual happiness is infringed by this noise. In this paper, We tried to visualize the spatial sound characteristics of public places using sound color to express them so that anyone can sympathize. The noise inside a conference room of a medical device company was measured for 100 minutes, and the frequency band was divided into three different types of existing sound pressure expression units. Because the size of the noise is expressed differently depending on the situation, There are cases where there is a difference of opinion between the measurer and the researcher. This noise measurement experiment was conducted, and the sound color was applied to classify it on a log scale considering auditory characteristics. As a result of comparing this with the result expression for different loudness expression units, A specific table in different units yielded almost similar results. In addition, the sound source section for 100 minutes was divided into three analysis sections, the analysis sections were different, and the size of the energy ratio for each analysis section was divided in the form of an envelope. The characteristics of the low-frequency region of the space have a high energy ratio, and the decrease in the energy ratio according to the increase in frequency is constant and regular. You can see that conversations are possible.

• 한국산업보건학회지
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• 제34권1호
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• pp.1-7
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• 2024

Objectives: The study was performed to investigate characteristics of hazardous factors regarding chemical(liquid lime) tank dredging workers by case survey. Methods: Field data such as working condition, MSDS and respirators applied to chemical tank dredging work were analyzed and the work environmental factors of noise and indoor air quality were measured to compare existing data with actual work situations. Results: No health hazards to workers due to working conditions were confirmed during dredging work inside the chemical storage tank. All air quality measurement data during dredging work satisfied the management standards, and there were no by-products. During dredging work, there was a significant change in noise depending on the type of work, but considering the noise reduction rate(NRR) of the earplugs worn by workers, there was no actual health hazard due to noise exposure. Conclusions: A fit test for respirator and the expiration date of the safety helmet should be observed to ensure an appropriate level of safety and health for dredging workers in the chemical storage tank.

• 대한기계학회논문집 C: 기술과 교육
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• 제2권1호
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• pp.9-13
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• 2014

현재 소비자들이 자동차를 선택하는 여러 이유 중에서, NVH 성능이 아주 중요한 역할을 하고 있다. 근래 하이브리드 및 전기자동차들은 전통적인 차량의 주요 소음원 이었던 엔진의 소음이 거의 발생되지 않아 자동차 실내의 소음에 대한 관심은 더욱 커지고 있다. 해외 참고문헌에 의하면 자동차 휠의 높은 Lateral Dynamic Stiffness(LDS)가 운전 중 발생되는 Structure Bone Noise(SBN)를 저감시키는 것으로 기술되어 있다. 하지만 유효한 기준 및 시험적 결과가 미비하여, 본 연구에서는 LDS가 서로 다른 휠에 동일 타이어를 부착하여 실내소음을 시험 측정하였다. 그 결과 휠의 LDS에 따라 실내소음이 변화되는 것을 확인하였다. 이는 휠의 최적설계로 실내소음의 저감이 가능할수 있다.

• 융합신호처리학회논문지
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• 제20권1호
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• pp.16-23
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• 2019

PM 2.5로 불리는 초미세먼지는 인간의 건강을 해치는 2.5 ㎛ 이하 직경의 입자크기를 갖는 공기 중의 미세먼지를 말하며, 미세먼지 집중도는 공기 질 정보로 사용할 수 있다. 사람은 일반적으로 90% 이상을 실내에서 거주하며 실내에 대한 공식적인 먼지 집중도 자료는 제공되지 않기 때문에, 본 연구는 실내의 관점에서 공기 질 측정에 초점을 두었다. 실내 먼지데이터 모니터링은 병원과 같은 환경에서 매우 중요할 뿐만 아니라 교실, 시멘트 공장, 컴퓨터 서버 룸, 석유화학 저장고 등의 장소에서도 유용하게 사용할 수 있다. 본 논문에서는 전자기파로부터 자유로운 실내 먼지 모니터링을 위해 맨체스터 코딩기법을 이용한 가시광 통신 시스템을 제안한다. 넓은 범위의 먼지 집중도를 포함한 중요한 실내 환경정보가 가시광 채널을 통해 전송된다. 강력한 주변광 및 저주파 잡음 제거를 위해 평균전압트레킹 기법을 사용한다. 입력광은 광다이오드에 의해 수신되고, 동시에 수신 마이크로콘트롤러에 의해 신호처리 한다. 사용자는 실시간으로 실내 공기 질 정보를 모니터링 할 수 있으며, 공기 질 정보에 따라 미리 적합한 대처를 할 수 있다.

• 한국주거학회논문집
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• 제8권2호
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• pp.71-84
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• 1997

The Purpose of this study is to estimate how inclination to move can be appeared by understanding the cognition of a resident on stress due to the residential environment. 240 housewives living in Chiniu were Questioned statistical analysis were used with factor analysis, F-test. Duncan's Multiple range analysis, stepwise regression analysis and stepwise discriminant analysis, The result were summarized as follows 1) The stress of residential environment were clissified by six factors indoor facility, educational environmental. indoor structure, air Pollution noise, traffic convenience. 2) The extent of a stress from residential environment was significantly different in the socio-demographic variable and housing-related variable. 3) The stress of residential environment were affected by the direction of house. 4) The variable discriminating inclination to move were the stress of residential environment(air Pollution). an educational level, the type of housing possession, residential Period and the size of house.

• 전기학회논문지
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• 제64권6호
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• pp.935-939
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• 2015

In this paper, we analyze indoor visible light communication environment based on LightTools. If the environments for VLC are too various, it is not easy to analyze the VLC environment using mathematical techniques. To overcome this problem, we use LightTools program for the analysis of various VLC environment.