• Title/Summary/Keyword: 안전 환경

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Numerical Analysis for Improvement of Windshield Defrost Performance of Electric Vehicle (전기자동차 전면유리 제상성능 개선을 위한 전산수치 해석)

  • Kim, Hyun-Il;Kim, Jae-Sung;Kim, Myung-Il;Lee, Jae Yeol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.5
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    • pp.477-484
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    • 2019
  • As the residence time in the vehicle increases, the passenger desires a pleasant and stable riding environment in addition to the high driving performance of the vehicle. The windshield defrosting performance is one of the performance requirements that is essential for driver's safe driving. In order to improve the defrosting performance of the windshield of a vehicle, relevant elements such as the shape of the defrost nozzle should be appropriately designed. In this paper, CFD based numerical analysis is conducted to improve defrost performance of small electric vehicles. The defrost performance analysis was performed by changing the angle of the defrost nozzle and the guide vane that spray hot air to the windshield of the vehicle. Numerical simulation results show that the defrosting performance is best when the defrost nozzle angle is $70^{\circ}$ and the guide vane installation angle is $60^{\circ}$. Based on the analytical results, the defrosting experiment was performed by fabricating the defrost nozzle and the guide vane. As a result of the experiment, it is confirmed that the frost of windshield is removed by 80% within 20 minutes, and it is judged that the defrost performance satisfying the FVMSS 103 specification is secured.

A Study on the Awareness of Visitors to King Mu Trekking Course Program of Iksan (익산 무왕길 탐방프로그램 이용자의 인식에 대한 연구)

  • Park, Yool-Jin
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.36 no.4
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    • pp.80-93
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    • 2018
  • The following results could be obtained from the research on awareness and satisfaction of the tourists who joined the program 'A Journey in Search of King Mu's Road'. With regard to awareness of the site tour program, tourists replied that they participated in the program mainly because of their interest in education for their children. They expressed great needs for the municipal government office to maintain walkways, signboards and guide maps as well as to reinforce safety facilities as a measure to increase satisfaction with the site tour on the part of visitors and tourists. In terms of satisfaction with operation and management of the site tour program, the contents of the program were highly appreciated while it turned out necessary to rediscover garden culture resources and to develop and operate an expanded internal tour course for tourists to look around inside the relics by utilizing the recently excavated Baekje historical resources. As a consequence, it might be expected possible to experience and educate the local history and garden culture thanks to the historical culture and environmental values that have been preserved in the Baekje cultural circles. Moreover, the importance of walking trips will be recognized for its effects to allow those who get tired from daily life to come into contact with nature, practice self-reflection and care for their health as well.

Music Teachers' Perceptions of the Music Therapy Curriculum in Special Education Schools (특수학교 음악교과의 운영과 음악치료적 접근에 대한 교사인식)

  • Gu, Sin-Sil;Hwang, Soon-Young
    • Journal of Music and Human Behavior
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    • v.16 no.1
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    • pp.89-117
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    • 2019
  • The purpose of this study was to explore and better understand special education music teachers' perceptions of their music curriculum. For this purpose, we conducted a focus group interview with seven special education music teachers. During the interview, four major themes and 14 sub-themes were identified. The main themes were the following: (a) types of applied activities and the goals of music classes (e.g., activities to be applied in various ways depending on the characteristics of the disability and intended outcome), (b) difficulty in implementing the music curriculum (e.g., lack of fit between textbook and students' chronological ages, lack of time and focus, self-evaluation of performance as a music teacher, (c) therapeutic experiences during music classes (e.g., expectation for positive effects through music therapy, joy of witnessing changes in students, and sense of togetherness), and (d) obstacles to the therapeutic approach of music classes and need for support (e.g., lack of professional knowledge regarding therapeutic approaches and problems with administrators and school environment). Based on these results, problems in implementing the music therapy approach as part of the music curriculum in special education schools are discussed and practical solutions for educators are offered.

Importance-Performance Analysis of the Livestock Organic Wastes Recycling Policy (축산 유기성 폐기물 자원화 정책의 중요도-만족도 분석)

  • Kim, Won-Tae;Suh, Dae-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.12
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    • pp.523-531
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    • 2018
  • The purpose of this paper is to derive priorities and implications for the organic resource conservation policy in the livestock sector. We conducted a survey on the importance-performance of the organic waste resource reclamation of livestock sector using a 5-point Likert scale. The importance average for the resource recycling of livestock organic waste was 3.63 and the average of performance was 3.04. As a result of the IPA on livestock manure recycling measures, it is necessary to improve feed quality, establish a local recycling system, increase demand for compost and liquid, enhance customer linkages, and develop cost reduction technologies. It requires intensive support for promoting the spread of odor reduction technologies and integrated management of biomass. It is necessary to introduce mid- and long-term measures such as the revival of feed in tariff, promote by-product feeding, establish solid fuel process management standards, create hygiene safety standards, develop eco-beads and promotion of feed conversion. It is required to strengthen support for the development of odor reduction technologies and prepare consultative organizations among related departments, develop eco-friendly solid fuel technology, and support policies for renewable energy certification.

Design of Hazardous Fume Exhaust System in Vacuum Pressure Impregnation Process Using CFD (CFD를 이용한 진공가압함침공정 내 유해가스 배출시스템 설계)

  • Jang, Jungyu;Yoo, Yup;Park, Hyundo;Moon, Il;Lim, Baekgyu;Kim, Junghwan;Cho, Hyungtae
    • Korean Chemical Engineering Research
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    • v.59 no.4
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    • pp.521-531
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    • 2021
  • Vacuum Pressure Impregnation (VPI) is a process that enhances physical properties by coating some types of epoxy resins on windings of stator used in large rotators such as generators and motors. During vacuum and pressurization of the VPI process, resin gas is generated by vaporization of epoxy resin. When the tank is opened for curing after finishing impregnation, resin gas is leaked out of the tank. If the leaked resin gas spreads throughout the workplace, there are safety and environmental problems such as fire, explosion and respiratory problems. So, exhaust system for resin gas is required during the process. In this study, a case study of exhaust efficiency by location of vent was conducted using Computational Fluid Dynamics (CFD) in order to design a system for exhausting resin gas generated by the VPI process. The optimal exhaust system of this study allowed more than 90% of resin gas to be exhausted within 1,800 seconds and reduced the fraction of resin gas below the Low Explosive Limit (LEL).

Evaluation of a Thermal Conductivity Prediction Model for Compacted Clay Based on a Machine Learning Method (기계학습법을 통한 압축 벤토나이트의 열전도도 추정 모델 평가)

  • Yoon, Seok;Bang, Hyun-Tae;Kim, Geon-Young;Jeon, Haemin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.41 no.2
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    • pp.123-131
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    • 2021
  • The buffer is a key component of an engineered barrier system that safeguards the disposal of high-level radioactive waste. Buffers are located between disposal canisters and host rock, and they can restrain the release of radionuclides and protect canisters from the inflow of ground water. Since considerable heat is released from a disposal canister to the surrounding buffer, the thermal conductivity of the buffer is a very important parameter in the entire disposal safety. For this reason, a lot of research has been conducted on thermal conductivity prediction models that consider various factors. In this study, the thermal conductivity of a buffer is estimated using the machine learning methods of: linear regression, decision tree, support vector machine (SVM), ensemble, Gaussian process regression (GPR), neural network, deep belief network, and genetic programming. In the results, the machine learning methods such as ensemble, genetic programming, SVM with cubic parameter, and GPR showed better performance compared with the regression model, with the ensemble with XGBoost and Gaussian process regression models showing best performance.

Detection of The Real-time Weather Information from a Vehicle Black Box (차량용 블랙박스 영상에서의 실시간 기상정보 검지)

  • Kang, Ju-mi;Lee, Jaesung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.10a
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    • pp.320-323
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    • 2014
  • Today is going with the advancement of intelligent transportation systems and traffic environment and helping to provide safe and convenient service through a mobile device work with the popularization of the vehicle black box. The traffic flow by a variety of causes is constantly changing, it is often unable to prepare the driver, depending on external factors can not be controlled by the power of the public, leading to a major accident. The system needs to pass the real-time weather data in the inter-operator to prevent this. The proposed detection algorithm weather information delivered real-time weather information for this paper. The weather condition is detected by using the contrast between the histogram of the motion of the wiper and the clear day algorithm. In general, the wiper is worked in extreme weather conditions that will have a value different contrast due to rain or snow. Situation was considered clear, snowy conditions, such as using it on a rainy situation. First, designated as ROI (Region Of Interest) of the minimum area that can be detected in order to reduce the amount of calculation for the wiper, the wiper, which was detected through the operation of the threshold Thresholding the brightness of the vehicle wiper. In addition, we distinguish the value of each meteorological situation by using contrast. Results was obtained to 80% for the snow conditions, a rainy situation.

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Numerical Simulation on Control of Tsunami by Resonator (I) (for Imwon and Mukho ports) (공진장치에 의한 지진해일파의 제어에 관한 수치시뮬레이션(I) (임원항과 묵호항에 대해))

  • Lee, Kwang-Ho;Jeon, Jong-Hyeok;Kim, Do-Sam;Lee, Yun-Du
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.32 no.6
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    • pp.481-495
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    • 2020
  • After the resonator on the basis of the wave-filter theory was designed to control the waves with a specific frequency range surging into the harbor, the several case with the use of resonator have been reported in some part of sea, including the port of Long Beach, USA, and yacht harbor at Rome, Italy in order to control the long-period wave motion from the vessels. Recently, the utility and applicability of the resonator has been sufficiently verified in respect of the control of tsunami approximated as the solitary wave and/or the super long-period waves. However, the case with the application of tsunami in the real sea have not been reported yet. In this research, the respective case with the use of existing resonator at the port of Mukho and Imwon located in the eastern coast of South Korea were studied by using the numerical analysis through the COMCOT model adapting the reduction rate of 1983 Central East Sea tsunami and 1993 Hokkaido Southwest off tsunami. Consequently, the effectiveness of resonator against tsunami in the real sea was confirmed through the reduction rate of maximum 40~50% at the port of Mukho, and maximum 21% at the port of Imwom, respectively. In addition, it was concluded that it is necessary to study about the various case with application of different shape, arrangement, and size of resonator in order to design the optimal resonator considering the site condition.

Study on the Analysis of Spatial Structure in Jeju Island Focusing on Parking Status (주차실태를 중심으로 한 제주도 공간구조 분석 연구)

  • Hwang, Kyung-Soo;Yang, Jeong-Cheol;Jo, Hang-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.2
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    • pp.667-675
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    • 2021
  • The purpose of this study is as follows: First, to analyze the spatial structure of Jeju by analyzing the rate of parking demand and supply; Second, to determine the parking service imbalance between regions; and third, to elucidate the causes of this spatial structural parking service imbalance and provide effective measures. Due to the rapid population and tourism growth, Jeju is suffering from traffic congestion and serious parking problems. For this, the ways to efficiently utilize the existing parking spaces were identified through spatial structure analysis based on the parking demand and supply in the Jeju area. As short-term policy, the following changes were proposed: switching to small-scale eup or myeon blocks of parking space, use of shared parking system, and repairing side streets in residential areas. As mid-to-long-term policy, it is linked to other means of transportation as follows: parking demand management policy through modal share by reorganizing public transportation routes or expanding traffic facilities; securing park-and-ride lots; and different parking pricing for different time periods. To implement these policies, each area of the public sector, private sector, and private-public partnership should develop the bond of sympathy by areas and participants.

Numerical Simulation on Control of Tsunami by Resonator (II) (for Samcheok port) (공진장치에 의한 지진해일파의 제어에 관한 수치시뮬레이션(II) (삼척항에 대해))

  • Lee, Kwang-Ho;Jeon, Jong-Hyeok;Kim, Do-Sam;Lee, Yun-Du
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.32 no.6
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    • pp.496-505
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    • 2020
  • In the previous research, the effectiveness of resonator was confirmed through the numerical analysis on two cases with the use of existing resonator at the Mukho and Imwon ports located in the eastern coast of South Korea by discussing the reduction rates of 1983 Central East Sea tsunami, and 1993 Hokkaido Southwest off tsunami, respectively. In this study, the reduction rates of tsunami height with three different resonators, Type I, II-1, and II-2, at the Samcheok port were examined respectively through the numerical analysis using COMCOT model under the same condition as the previous study. It was discussed the spatial distribution of maximum height of tsunami, change of water level, and effectiveness of resonator with the presence of new types of resonator, and change of their sizes. As a result, the effectiveness of resonator was verified through the application of new types of resonator reducing about maximum 40% of tsunami height. In order to design the optimal resonator for the variety of site condition, it is necessary to research about the various cases applying different shape, arrangement, and size of resonator as further study.