• Title/Summary/Keyword: maintenance method

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Monthly Water Balance Analysis of Hwanggang Dam Reservoir for Imjin river in Border Area using Optical Satellite (광학위성을 활용한 임진강 접경지역 황강댐 저수지의 월단위 물수지 분석)

  • KIM, Jin-Gyeom;KANG, Boo-Sik;YU, Wan-Sik;HWANG, Eui-Ho
    • Journal of the Korean Association of Geographic Information Studies
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    • v.24 no.4
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    • pp.194-208
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    • 2021
  • The Hwanggang Dam in North Korea is located upstream of the Imjin River which is a shared river in the border area. It is known to have a reservoir capacity of 350 million cubic meters and releases a discharge primarily for generating hydroelectric power and partly for transferring to the Yesung River basin. Due to the supply of water from the Hwanggang Dam to another basin, the flow of the Imjin River has decreased, which has a negative impact on the water supply, river maintenance flow, water quality, and ecological environment in Korea. However, due to the special national security issue of the South and North Korea border region, the hydrological data is not shared, and the operation method of the Hwanggang Dam is unknown, so there is a risk of damage to the southern part of the downstream area. In this study, the monthly diversion as the long-term runoff concept was derived through the calibrated hydrological model based on optical remotely sensed Images and water balance analysis. As a result of the water balance analysis from January 2019 to September 2021, the average diversion of the Hwanggang Dam was 29.2m3/s, which is equivalent to 922 million tons per year and 45.6% of the annual inflow of 2.02 million tons into the Hwanggang Dam.

Analysis of Time Series Changes in the Surrounding Environment of Rural Local Resources Using Aerial Photography and UAV - Focousing on Gyeolseong-myeon, Hongseong-gun - (항공사진과 UAV를 이용한 농촌지역자원 주변환경의 시계열 변화 분석 - 충청남도 홍성군 결성면을 중심으로 -)

  • An, Phil-Gyun;Eom, Seong-Jun;Kim, Yong-Gyun;Cho, Han-Sol;Kim, Sang-Bum
    • Journal of Korean Society of Rural Planning
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    • v.27 no.4
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    • pp.55-70
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    • 2021
  • In this study, in the field of remote sensing, where the scope of application is rapidly expanding to fields such as land monitoring, disaster prediction, facility safety inspection, and maintenance of cultural properties, monitoring of rural space and surrounding environment using UAV is utilized. It was carried out to verify the possibility, and the following main results were derived. First, the aerial image taken with an unmanned aerial vehicle had a much higher image size and spatial resolution than the aerial image provided by the National Geographic Information Service. It was suitable for analysis due to its high accuracy. Second, the more the number of photographed photos and the more complex the terrain features, the more the point cloud included in the aerial image taken with the UAV was extracted. As the amount of point cloud increases, accurate 3D mapping is possible, For accurate 3D mapping, it is judged that a point cloud acquisition method for difficult-to-photograph parts in the air is required. Third, 3D mapping technology using point cloud is effective for monitoring rural space and rural resources because it enables observation and comparison of parts that cannot be read from general aerial images. Fourth, the digital elevation model(DEM) produced with aerial image taken with an UAV can visually express the altitude and shape of the topography of the study site, so it can be used as data to predict the effects of topographical changes due to changes in rural space. Therefore, it is possible to utilize various results using the data included in the aerial image taken by the UAV. In this study, the superiority of images acquired by UAV was verified by comparison with existing images, and the effect of 3D mapping on rural space monitoring was visually analyzed. If various types of spatial data such as GIS analysis and topographic map production are collected and utilized using data that can be acquired by unmanned aerial vehicles, it is expected to be used as basic data for rural planning to maintain and preserve the rural environment.

Model-based Efficiency Analysis for Photovoltaic Generation O&M: A Case Study (태양광발전 운전 및 유지보수를 위한 모델기반 효율분석: 사례연구)

  • Yu, Jung-Un;Park, Sung-Won;Son, Sung-Yong
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.15 no.5
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    • pp.405-412
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    • 2022
  • This paper studies the method of estimating power loss and classifying the factors for improving the power generation efficiency through O&M. It is installed under various climatic conditions worldwide, operational and maintenance technologies suitable for the characteristics of the installation location are required. Existing studies related to solar power generation efficiency have been actively quantifying the impact on short-term losses by environmental factors such as high temperature, dust accumulation, precipitation, humidity, and wind speed, but analysis of the overall impact from a long-term operation perspective is limited. In this study, the potential for efficiency improvement was analyzed by re-establishing a loss classification system according to the power flow of solar power to derive a comprehensive efficiency model for long-term operation and estimating power loss through a case study for each region where climate conditions are classified. As a result of the analysis, the average annual potential for improving soiling loss was 26.9%, Death Valley 7.2%, and Seoul 3.8%. Aging losses was 6.6% in the 20th year as a cumulative. The average annual potential due to temperature loss was 2.9 % for Doha, 1.9% for Death Valley, and 0.2% for Seoul.

Analysis of Electrical Characteristics of CCFL Exit Light (CCFL유도등의 전기적 특성 분석)

  • Jung, Jong-Jin
    • Journal of the Society of Disaster Information
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    • v.17 no.1
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    • pp.184-193
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    • 2021
  • Purpose: In this study, since the operation principle of the CCFL Exit light is the same as that of general lighting equipment, the characteristics of the CCFL Exit light were analyzed by deriving test items that can affect the characteristics of the light source from the KS standard, which is the standard for lamp ballast performance certification of general lighting equipment. Method: The samples used in the experiment were performed on products of two manufacturers for each size, such as large, medium, and small, and the test items were power factor, crest factor, and current harmonic distortion. Result: As a result of the experiment, the power factor showed a value between 0.4 and 0.6 in all samples, which was smaller than the 0.9 value set by KS. The crest factor ranged from 3.6 to 3.7 for large, 4.4 to 4.7 for medium, and 3.5 to 3.7 for small. It showed a value more than two times higher than the KS standard of 1.7. Current total harmonic distortion ranged from 81% to 110%, and considering that the KS standard was less than 20%, it could be confirmed that all samples had a value significantly exceeding the KS standard. Conclusion: The crest factor and current total harmonic distortion may affect the temperature rise of the light source and the burnout of the device. When developing an exit light, if this item is developed within the scope of the KS standard, the quality improvement and maintenance of the exit light will be greatly improved.

Analysis on Media Reports of the 「Security Services Industry Act」 Using News Big Data -Focusing on the Period from 1990 to 2021-

  • Cho, Cheol-Kyu;Park, Su-Hyeon
    • Journal of the Korea Society of Computer and Information
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    • v.27 no.5
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    • pp.199-204
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    • 2022
  • The purpose of this study is to broaden the understanding of the Security Services Industry Act, and also to examine the meanings of various phenomena by analyzing the media report big data rather than the researchers' perspective on the Security Services Industry Act. In the research method, this study searched for a keyword 「Security Services Industry Act」 that prescribes the security work as an important subject of crime prevention and maintenance of public order in Korea. The data was searched from 1990 to 2021 the BIG KINDS could provide. Also, for the concrete analysis during the period of data search, it was divided into settlement period(1976~2001), growth period-quantitative(2002~2012), and growth period-qualitative(2013~2021). In the results of this study, the media report perception of the Security Services Industry Act is continuously emphasizing the social roles and importance of private security according to the flow of time. The consequent marketability of private security will play great roles in the protection of people's lives and properties in the combination with various other industries in the future. However, the private security industry that provides public peace service together with the police, could be rising as an element that hinders the development of private security industry because of various social issues caused by legal regulations and illegal problems, so it would be necessary to more strengthen its responsibility and roles accordingly.

A Study of Improvements in the Standards of Cost Estimate for the New Excellent Technology in Construction (건설 신기술의 원가산정기준 개선방안에 대한 연구)

  • Lee, Ju-hyun;Tae, Yong-Ho;Baek, Seung-Ho;Kim, Kyoungmin
    • Korean Journal of Construction Engineering and Management
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    • v.23 no.5
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    • pp.65-76
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    • 2022
  • The New Excellent Technology (NET) designation system, introduced in 1989 for the purpose of promoting the development of domestic construction technology and enhancing national competitiveness, reviews the statement of construction cost of new technologies. And the cost reduction effect such as design, construction, and maintenance cost and the effect of reducing the construction duration are evaluated as an evaluation criteria of economic feasibility. However, in this evaluation process, differences of opinion between the institution of construction cost estimating standard management and the new technology developer about unique technologies frequently occur. In addition it is difficult to objectively compare the construction duration with existing similar technologies because there is no information on productivity as the current cost estimating standards for new technologies only present the required amount per unit quantity. In this study, the current state of cost estimating criteria review procedure, evaluation criteria, and cost estimating standards establishment method were analyzed when screening for the designation of a new construction technologies, and compared with overseas cost estimating standards, measures to improve the cost estimating standards of current construction new technologies were suggested. Through the improved cost estimating standards of this study, it is expected that cost information on new technologies will be provided to clients in more detail than the current ones, and the availability and applicability of new construction technologies would be improved by simplifying the construction cost calculation process more.

Comparison of the Postoperative Pain Control Effects of a Buprenorphine Transdermal Patch on Total Knee Arthroplasty Surgery Patients according to Its Applied Sites: Retrospective Case-Control Study (슬관절 인공관절 전치환술 환자에서 부프레노르핀 경피 패치의 적용부위에 따른 수술 후 통증 조절 효과 비교: 후향적 환자-대조군 연구)

  • Kim, Ok-Gul;Lee, Sang-Wook;Kim, Hyun-Min
    • Journal of the Korean Orthopaedic Association
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    • v.55 no.6
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    • pp.527-533
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    • 2020
  • Purpose: This study compared the effects of a buprenorphine transdermal patch (BTDP) on the chest and knee for pain control after total knee arthroplasty (TKA). Materials and Methods: A retrospective case-control study was conducted from August 2018 to August 2019 on 231 patients who underwent TKA. Two hundred cases were selected considering age, sex, and body mass index. Before and after applying the BTDP, the Numeric Rating Scale (NRS), adverse effects and compliance were measured. All measurements in the chest application group (group A=100) and knee application group (group B=100) were compared. Results: NRS was similar in rest between the groups treated with BTDP, but at two days and three days afternoon, five, six, and seven days postoperatively in group B, the NRS was significantly lower than that of group A. The adverse effects of the central nervous system and gastrointestinal system after applying BTDP were significantly lower in group B than in group A. No significant differences in adverse effects of the cardiovascular system and skin were observed between the two groups. Regarding the maintenance of BTDP, group B was significantly higher than group A. Conclusion: The direct application of BTDP after TKA to painful knee joints showed excellent results in early postoperative pain control and can be a useful method for increasing patient compliance by reducing the frequency of adverse effects.

A Study on the Application of IPA Method for Exploring the Properties of Urban Residents' Choice of Indoor Plants

  • Jeong, Na Ra;Kim, Kwang Jin;Yoon, Ji Hye;Han, Seung Won;You, Soojin
    • Journal of People, Plants, and Environment
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    • v.23 no.6
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    • pp.603-614
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    • 2020
  • Background and objective: This study was conducted to understand urban residents' perception of indoor plants in order to assist in the preparation of guidelines for growing plants indoors. Methods: Questionnaires were distributed to urban residents currently growing plants or with experience of growing plants. The data of 247 respondents were subjected to analysis to assess their level of interest and ability with regard to growing plants, and their recognition of the selection and function of plants. Results: Respondents showed high interest in growing plants at a level of 6.77, but their ability was moderate. This suggests that information regarding plant maintenance should be provided to urban residents. They recognized the function of plants for improving the environment as important, and expected that indoor plants would improve their mood and visual experience. Satisfaction with growing plants was high from an emotional perspective. They recognized that the function of air purification function was important even if the actual performance or effect was not great. This indicates that the function of air purification should be emphasized more. As the result of the IPA, plants should be selected in consideration of morphological characteristics such as leaf, flower and fruit, and continuously managed to maintain their characteristics. Since the performance of pots was less satisfactory compared to their importance, they should be selected so that they harmonize better with plants and are of the appropriate size to fit the space. The type of plants is an important factor in plant selection in order to perform an environmental function, and the flower color and pot size are important in terms of aesthetics and healing. Conclusion: When horticulture information on indoor plants is provided to urban residents, first, it should be provided to satisfy the functions of the plants required by urban residents and in order to promote and maintain the proper growth of plants. Second, various contents that utilize components should be developed to achieve plant function so that resident can determine the function of plants and select the type, quantity, and shape of plants to achieve the desired function.

Developed Vacuum Film Packaging Method Maintains Quality of Enoki Mushrooms (Flammulina velutipes) during Simulated Vessel Export to Vietnam (팽이버섯의 베트남 모의수출 중 진공포장방법 개선을 통한 품질 유지 효과)

  • Choi, Ji Weon;Lim, Sooyeon;Lee, Ji Hyun;Eum, Hyang Lan;Lee, Jung-Soo;Park, Hye Sung;Im, Ji-Hoon;Do, Kyung Ran
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.28 no.2
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    • pp.133-142
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    • 2022
  • Korean enoki mushrooms are exported to Southeast Asia and the United States, where there are complaints due to quality deterioration during the distribution process. In this study, we evaluated the efficacy of vacuum film packaging on quality maintenance in Korean enoki mushrooms during simulated vessel export to Vietnam using selected film, which was developed with vacuum packaging machine and oxygen absorber. We selected two MA film, one was 2-layerd 30 ㎛ CPP film (control) and the other was 3-layered 30 ㎛ CPP film (treatment) which is optimized film of higher gas and moisture permeability. The Korean enoki mushrooms were packaged with these two films using PAC-2000 or PAC-3000 vacuum packaging machine which was improved vacuuming of higher speed. Packed mushrooms were stored at 1℃ for 2 weeks and distributed at 20℃ for 2 days or 8℃ for 6 days. The efficiency of the film packaging was analyzed by vacuum maintaining index, and overall the quality characteristics such as off odor, color, cap cleavage, stem elongations and sensory evaluation were evaluated during storage and distribution. Results suggest that postharvest loss of fresh enoki mushroom could be reduced by packaging mushroom with 3-layered 30 ㎛ CPP films packaged using PAC-3000 machine during simulated vessel export to Vietnam due to vacuum maintaining. Oxygen absorber promoted off-odor at 20℃ distribution temperature, and did not affect storability at 1℃ storage compared to treated group without oxygen absorber treatment.

A Systemic Review of Positive Behavior Support Intervention Studies on Problem Behaviors of Children With Autism Spectrum Disorders: Focusing on Korean Single-Subject Research Design (자폐스펙트럼장애 아동의 문제행동에 대한 긍정적 행동지원 중재 연구의 체계적 고찰: 단일대상연구 설계를 중심으로)

  • Yoo, Yung-Mee;Choi, Yoo-Im
    • Therapeutic Science for Rehabilitation
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    • v.10 no.4
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    • pp.7-24
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    • 2021
  • Objective : This study examined the characteristics of the literature involving a single-subject research design among positive behavior support intervention studies to improve problem behavior in children with autism spectrum disorders and assess the quality level. Methods : This is a literature study, and the targets of analysis were nine single-subject research papers published between 2011 and 2020. The subject papers were analyzed by dividing them into general characteristics and the qualitative levels according to the content of the research method. Results : Analysis of analyzing the contents of the study showed that the subjects were preschool and elementary school-age children at the same ratio. Furthermore, the study design involved mostly the middle and multiple baseline designs among the behaviors. All papers presented social validity, intervention fidelity, and observer reliability. Problem behaviors included self-injury and aggression behaviors, disturbing behaviors, and seat break-away behaviors, while the most dependent variables were measured through partial interval recording. As a result of confirming the intervention effect, the effect was confirmed in intervention, maintenance, and generalization. All analysis studies showed high-quality levels. Conclusion : This study confirmed the content and qualitative level of the thesis that applied the single-subject research design among positive behavior support intervention studies for problem behaviors of children with autism spectrum disorders. Positive behavior support intervention, an evidence-based intervention for children with autism spectrum disorders, was confirmed an effective intervention for autism spectrum disorders.