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        검색결과 23

        1.
        2023.11 구독 인증기관·개인회원 무료
        In general, systems are developed by repeatedly performing the processes of design, analysis, manufacturing, and performance testing. In particular, systems with temperature, pressure, and flow rate often utilize computational fluid dynamics tools at the design stage. In this paper, we aim to verify the reliability of the analysis results of Solidworks Flow Simulation, which is widely used in heat flow analysis at the design stage. A tube furnace was manufactured, various experiments were performed, and a study was conducted to compare the analysis results. The details of the experiment are as follows. First, an experiment was conducted in which the heater was heated to 900°C without insulating the exposed part of the tube. The detailed contents of the experiment are as follows; - Heating heater and measuring temperature without supplying flow inside the tube, - Tube flow supply (25°C, 15 lpm air) and heater heating/temperature measurement. Second, an experiment was performed in which the exposed part of the tube was insulated (thickness 50 mm) and the heater was heated to 900°C. The detailed contents of the experiment are as follows; - Insulate the outside of the tube except for the flanges at both ends of the tube, and heat the heater and measure the temperature without supplying flow inside the tube. - Insulate the outside of the tube except for the flanges at both ends of the tube, supply flow rate inside the tube (25°C, 15 lpm air) and measure heater heating/temperature. - Insulate the flange of the flow supply section, heat the heater and measure temperature without supplying flow inside the tube. - Insulate the flange of the flow supply section, heat the supply air (277°C, 15 lpm) and measure the temperature using a heating gun without heating the heater. - Insulate the flange of the flow supply section, supply heated air (277°C, 15 lpm) and measure heater heating/temperature. - Insulate the flange of the flow supply section and measure temperature according to heater heating (900°C) and supply temperature (25°C, 277°C 15 lpm). The following results were derived from the experimental and analysis results. - When the exposed part of the tube is insulated, the temperature inside the tube increases and the steady-state power decreases compared to non-insulated. - In areas with insulation, the temperature error between experiment and analysis results is not large. - When flow rate is supplied, there is a large temperature error in experiment and analysis results. - The temperature change after the center of the heater is not large for a temperature change of 15 lpm flow rate. From these results, it can be seen that Solidworks Flow Simulation has a significant difference from the experimental results when there is a flow rate in the tube. This was thought to be because the flow rate acts as a disturbance, and this cannot be sufficiently accounted for in the analysis. In the future, we plan to check whether there is a way to solve this problem.
        3.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, a mixed resin containing Bis-GMA was developed to produce a light-emitting sign using quantum dots. As a result of measuring the viscosity, color coordinates change, and luminance of the mixed resin, the following conclusions were obtained. The viscosity of the mixed resin decreased as the content of the diluent increased, and viscosity values ​​ranged from 3,627 to 1,349cps showed as a result. The viscosity of the mixed resin decreased as the temperature increased, and the viscosity showed a value of 5,156 to 1,132cps. For the optical properties of InP/GaP/ZnSe/ZnS quantum dots, the absolute quantum efficiency was 91% at 522nm and 90% at 618nm when the gallium was 0.01%. The luminance of the light-emitting sign using the resin mixed with quantum dots was showed 142.6cd/m2 in white and 104.2cd/m2 in the red region.
        4,000원
        5.
        2021.06 구독 인증기관 무료, 개인회원 유료
        This paper presented a case of the ICT Innovation Centres in Primary Schools in Kenya for the effective operation and management of ICT integrated education based on the results of the centre users’satisfaction and improved competency in ICT in education. Global society pursed results-based management to materialize the principles of effective development cooperation. In line with the principle, the project team for establishing the Centres has supported the local operators to operate and manage the centres with the manual and surveyed to capture the results of the operation and management focusing on the users' satisfaction and competency. As result, these two centres encouraged the users to be exposed to use facilities and equipment for understanding ICT and applying it in their teaching and learning activities physically. In particular, these centres helped them to participate in community activities which were recognized as the foundation of sustainable operation and management of the centres. The teaching and learning environment significantly affected the users' satisfaction and improved competency. But, still, additional content would be required for enhancing the performance of the users. For the long-term results, this study proposed that the impact of using the centres should be monitored continuously to carry out tangible results of teaching and learning performance because the centres were operated less than a year and still required to stock relevant data.
        4,000원
        6.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Since the implementation of the Odor Prevention Act in 2005, the number of odor complaints has continuously increased due to the increased interest in the living environment. The current odor control means is a concentrationbased method for the source of odor. That is why there is a difference between the odor sensitivity and the result of the odor measurement in the odor damage area. The government is considering the introduction of the grid method, which is the odor management method of Germany, as the method of odor investigation in the odor damage area in the second comprehensive Odor Prevention Policy (2019-2028). The grid method is receptor-based odor measurement method that investigators use to judge odors in the field, task that expensive and requires substantial manpower and time. To study an odor measurement method that is suitable for domestic conditions, this study compared the correlation between results based on the odor frequency concept grid method around the livestock facilities and the result of ammonia concentration measured by passive air sampler. The correlation coefficient (R) that is between the frequency of odor per spot for the entire odor and the ammonia concentration that was measured by passive air sampler was 0.65 which is relatively good. Among the entire odor detected by the grid method, the correlation coefficient (R) between the odor frequency selected only for livestock odor and the ammonia concentration was significantly increased to 0.80. In addition, the correlation between odor exposure (ECPexist) and the ammonia concentration for the overall odor was 0.81 (linear) and 0.86 (index). If only the livestock odors were selected, the correlation between odor exposure and the ammonia concentration was very high at 0.96 (linear) and 0.95 (index).
        4,000원
        9.
        2017.04 구독 인증기관 무료, 개인회원 유료
        In order to secure competitiveness of companies in the semiconductor industry, state management of equipment is one of the most important key factors. Particularly, after carrying out preventive maintenance (PM) work to maintain the best equipment condition, process reliability inspection is carried out. This work must be performed manually by the intervention of the operator. This inspection work is becoming more and more difficult due to the difficulty of the manufacturing worker, the increase of the simple repetitive workload, and the increase of the inspection items for the engineer, as the condition and the procedure continuously change as the semiconductor scaling down. Therefore, we would like to carry out an empirical study on the construction of an automatic inspection system in order to carry out the more reliable and efficient inspection procedure by eliminating the problems and unreasonableness of the past based on the investigation and analysis of the work procedures and conditions of the existing manual method.
        4,000원
        10.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study of small & Medium-Sized construction sites construction disaster prevention technology conduction-site visits from the map results report by the inspector on-site advice and technical guidance for the analysis of deficiencies and potential construction of disaster revealed the potential factors causing an accident as follows. As a results, Should not be a once a month visits. Therefore should be changed at least twice a month to help prevent accidents of this system is to be judged.
        4,000원
        14.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        바람에 의한 초고층 건축물의 거동은 매우 복잡하기 때문에 구조체에 대한 풍하중의 설계는 매우 어렵다. 현재 사용되고 있는 풍하중 산출방법은 풍동실험에 의존하고 있으며, 1차 탄성거동을 전제로 행해지고 있다. 가장 불리한 조건인 1차 모드로 가정하는 것은 다소 과대설계가 되어 안전하지만, 비경제적이다. 따라서 초고층 건축물에 작용하는 풍하중은 다차 모드 해석에 의해 산출하는 것이 안전성과 경제성을 동시에 확보할 수 있는 방법일 것이라 판단된다. 다차 모드를 고려한 풍하중의 산정은 풍압적분법(Pressure Integral Method)을 응용하면 가능하다. 본 연구는 풍압적분법(Pressure Integral Method)의 유효성을 검증하는 것이 목적이며, 공력진동실험에 의한 풍응답 해석결과와 비교하여 그 유효성을 검증하였다.
        4,000원
        15.
        1997.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Several studies have evaluated the effects of types of relative frequency and delay interval of knowledge of results(KR) on motor skill learning independently. The purpose of this study was to determine more effective types of KR relative frequency and KR delay interval for motor learning. Forty-six healthy subjects (15 female, 31 male) with no previous experience with this experiment participated. The subjects ranged in age from 20 to 29 years (mean=23.9, SD=0.474). All subjects were assigned to one of four groups: a high-instant group, a high-delay group, a low-instant group, and a low-delay group. During the acquisition phase, subjects practiced movements to a target (400 mm) with either a high (83%) or low (33%) KR relative frequency, and with either an instantaneous or delayed (after 8s) KR. Four groups were evaluated on retention (after 3min and 24hr) and transfer (450 mm) tests. The major findings were as follows: (1) there were no between-group differences in acquisition and short-term retention (p>0.05, (2) a low (33%) KR relative frequency during practice was as effective for learning as measured by both long-tenn retention and transfer tests, compared with high (83%) KR practice conditions (p<0.05), (3) delayed (8s) KR enhanced learning as measured by both long-term retention and transfer tests, compared with instantaneous KR practice conditions (p<0.05), and (4) there were no interactions between KR relative frequency and KR delay interval during acquisition, retention, and transfer phases. The results suggest that relatively less frequent and delayed KR are more effective types for motor learning than more frequent and instantaneous KR.ㅂ
        4,800원
        16.
        2021.12 KCI 등재 서비스 종료(열람 제한)
        이 연구는 한국해양과학기술원 동해연구소 독도전문연구센터가 동해의 바닷속 펼쳐진 거대한 독도의 해양영토를 밝히고 그 가치를 찾아 한국의 영토로서 확고한 주권확립과 이용관리에 기여하고 있으며, 과학연구 활동으로 많은 성과를 이루어내고 있기 때문에 독도 해양과학연구 성과를 중심으로 홍보현황과 활성화 방안에 대하여 조사와 분석을 한 것이다. 이 독도전문연구센터는 2006년도에 설립되어 올해 16년째 독도 해양과학연구를 꾸준 히 하고 있으며, 축적된 연구 성과에 대하여 홍보를 하였다. 이러한 독도 해양과학연구 성과의 홍보 방법으로는 학술논문, 학술활동, 특허, 서적출간, 언론홍보, 전시회 및 학술행 사, 독도관련 화보집, 총서와 독도체험시스템 등이 있다. 독도전문연구센터의 독도 해양과 학연구 성과의 홍보현황을 보면 2006년부터 2020년까지 학술논문은 82편, 학술발표 226편, 특허 11건, 서적 35종, 언론홍보 1158건, 전시회 32건, 학술행사(워크숍, 세미나, 심포지엄 등) 227건, 대중강연 107건, 견학(방문) 791건, 자료제공 226건 등 약 3천건 정도로 집계되었다. 독도 시민단체와 반크 등 일반인의 독도 홍보활동은 많이 이루어지고 있지만, 독도 해양과학 연구자들의 독도 성과와 홍보에 관한 것은 아직 충분치 않은 실정이 라고 할 수 있다. 그래서 본고에서는 다음과 같은 활성화 방안을 제시하였다. 첫째, 새로운 해양, 해저지형 표기에 있어서 동도, 서도 외 89개 부속 섬의 전체 바위명칭 부여 및 지도, 리플릿 제작 배포가 필요하다. 둘째, 독도 이용개발에 있어서 육상의 경우에는 자연환 경에 의한 풍화작용 등의 영향으로 바위가 훼손되는 현상을 지속적으로 모니터링 해야 한다. 셋째, 독도 해양 및 환경자료 활용을 확대하여 독도 통합관측시스템을 구축 및 운영하 여 실시간 서비스 제공도 지속적이어야 한다.
        17.
        2019.10 KCI 등재 서비스 종료(열람 제한)
        건강증진센터를 방문한 환자를 대상으로 CT 지방측정 위치에 따른 내장지방 면적과 Inbody로 측정한 내장지방 면적의 차이를 비교하여 보았다. CT 지방측정에서 L4-5와 CT Umbilicus 위치에서 측정한 내장지방 면적은 남·여 성별에 다른 차이는 없었다. 또한, CT 지방측정 위치에 따른 내장지방 면적과 Inbody로 측정한 내장지방 면적과의 상관관계에서 CT 내장지방 면적과 Inbody로 측정한 내장지방 면적 간의 차이가 없 었다. CT 내장지방 측정 위치는 남자 L4-5, L5-S1 위치, 여자 L3-4, L4-5, L5-S1, Umbilicus 위치에서 높은 상관관계를 보였다. Inbody 내장지방 면적과 CT 내장지방 면적 관계 간의 연구를 할 때 CT L4-5 위치의 내 장지방 면적과 비교하는 것을 제안한다.
        18.
        2019.10 서비스 종료(열람 제한)
        2018년도 시설물의 안전 및 유지관리에 관한 특별법이 전면 개정됨에 따라 제1종 및 제2종시설물 중에서 사회기반시설물 범주에 해당하는 시설물(이하 ‘성능평가 대상시설물’)에 대해 성능평가를 실시하도록 하여 성능등급을 지정하도록 하고 있다. 본 연구에서는 성능평가를 통해 도출된 시설물별 성능등급을 시설물 유형별로 성능등급으로 분석할 수 있는 방법을 도출하고 그 결과를 개선할 수 있는 방안에 대해 고찰하였다.
        19.
        2019.01 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 최근의 토양통 개정 결과를 반영하여 제주도를 대상으로 새로운 수문학적 토양군 분류 방법을 제시하였다. 또한 제시한 수문학적 토양군 분류 방법은 기존의 수문학적 토양군 분류 방법과 비교하여 평가하였다. 이를 위해 본 연구에서 제시한 수문학적 토양군 분류 방법과 기존의 수문학적 토양군 방법들을 적용하여 제주도 전체 유역을 대상으로 CN 값을 산정하고 그 결과를 비교하였다. 그 결과를 정리하면 다음과 같다. (1) 2007년 이후 개정된 토양통을 기존 토양통과 비교한 결과, 토성은 43개의 토양통에서, 배수등급은 1개의 토양통에서, 투수속도는 15개의 토 양통에서, 불투수층 깊이는 26개의 토양통에서 변경된 것으로 확인되었다. (2) 개정된 토양통을 반영하여 제주도의 수문학적 토양군을 분류한 결과, 1987년의 분류 방법을 따를 경우에는 수문학적 토양군 C군(46.43%)이 가장 많이 나타나나, 1995년의 분류 결과에서는 B군(27.69%)이, 2007년의 분류 결과에서는 D군(35.82%)이, 본 연구에서 제시한 분류 결과에서는 B군(49.25%)이 가장 많이 나타나는 것으로 나타났다. (3) 본 연구에서 제시한 방법을 제주도 전체에 적용한 경우에 추정된 CN 값은 기존 방법에 의한 값보다 작은 것으로 나타났다. 이 결과는 기존 방법을 적용할 경우 CN 값이 과대 추정되었을 가능성을 제시하는 것이기도 하다.
        20.
        2016.04 서비스 종료(열람 제한)
        In this study, repair and reinforcement priority determining method for each component of existing dams is suggested. Condition assessment results from in-depth inspection followed by “specific guide for in-depth inspection on dams” are used. Condition assessment is subdivided into several steps and evaluation indices are determined by considering weights such as influence coefficients and adjustment factors for each component through all of the steps. These weights are counted backward to determine the priority for each component and facility. An algorithm is designed to analyze this procedure and 4 target dams are adopted to verify the method. This method can be used for establishing an efficient maintenance strategy related to the repair and reinforcement priority determination.
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