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        검색결과 52

        3.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        곧 다가올 미래에는 자율운항선박, 육상 원격제어센터에서 제어되는 선박, 그리고 항해사가 탑승하여 운항하는 선박이 함 께 공존하며 해상을 운항할 것이며, 이러한 상황이 도래했을 때 해상 교통 환경의 안전을 평가할 수 있는 방법이 필요할 것으로 사료 된다. 이에 본 연구에서는 자율운항기술을 사용하여 항해사가 직접 조종하는 선박과 자율운항선박이 공존하는 해상환경 하에서 선박 조종시뮬레이션을 통해 통항 안전성을 평가하기 위한 방안을 제시하였다. 자선은 6-자유도 운동 기반의 MMG 모델을 심층 강화학습 기법 중 하나인 PPO 알고리즘으로 학습하여 자율운항 기능을 갖출 수 있도록 설계하였다. 타선은 평가 대상 해역의 해상 교통 모델 링 자료로부터 선박이 생성되도록 하였고, 기 학습된 선박모델을 기반으로 자율운항 기능을 구현되도록 하였다. 그리고 해양기상 자 료 데이터베이스로부터 조위, 파랑, 조류, 바람에 대한 자료를 수집하여 수치 모델을 수립하고 이를 기반으로 해양기상 모델을 생성하 여 시뮬레이터 상에서 해양 기상이 재현되도록 설계하였다. 마지막으로 안전성 평가는 기존의 평가 방법을 그대로 유지하되, 선박조 종시뮬레이션에서 해상교통류 시뮬레이션을 통한 충돌 위험성 평가가 가능하도록 하는 시스템을 제안하였다.
        4,000원
        4.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to develop virtual reality (VR)-based content on surgical aseptic techniques for nursing students and evaluate its effectiveness. Methods: The content was developed following the system development life cycle, involving analysis, design, implementation, and evaluation. Experts and fourth-year nursing students validated the content for its validity and usability of the content. The study was conducted from December 2022 to April 2023. Results: The VR content was developed using Keller's ARCS motivational design model (attention, relevance, confidence, and satisfaction) as the fundamental strategy. Upon applying the VR content developed in this study, the research participants confirmed the values of the following sub-factors: confidence (3.86 out of 5), relevance (3.74 out of 5), attention (3.68 out of 5), and satisfaction (3.65 out of 5). Conclusion: VR-based surgical content on aseptic techniques demonstrates potential benefits for nursing students. Therefore, through systematic development and utilizing of diverse nursing skill content, we can enhance the core competencies of nursing students, providing them with high-quality practical education.
        4,800원
        5.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to develop virtual reality (VR)-based content on surgical aseptic techniques for nursing students and evaluate its effectiveness. Methods: The content was developed following the system development life cycle, involving analysis, design, implementation, and evaluation. Experts and fourth-year nursing students validated the content for its validity and usability of the content. The study was conducted from December 2022 to April 2023. Results: The VR content was developed using Keller's ARCS motivational design model (attention, relevance, confidence, and satisfaction) as the fundamental strategy. Upon applying the VR content developed in this study, the research participants confirmed the values of the following sub-factors: confidence (3.86 out of 5), relevance (3.74 out of 5), attention (3.68 out of 5), and satisfaction (3.65 out of 5). Conclusion: VR-based surgical content on aseptic techniques demonstrates potential benefits for nursing students. Therefore, through systematic development and utilizing of diverse nursing skill content, we can enhance the core competencies of nursing students, providing them with high-quality practical education.
        4,800원
        7.
        2023.11 구독 인증기관·개인회원 무료
        Economical radioactive soil treatment technology is essential to safely and efficiently treat of high-concentration radioactive areas and contaminated sites during operation of nuclear power plants at home and abroad. This study is to determine the performance of BERAD (Beautiful Environmental construction’s RAdioactive soil Decontamination system) before applying magnetic nanoparticles and adsorbents developed by the KAERI (Korea Atomic Energy Research Institute) which will be used in the national funded project to a large-capacity radioactive soil decontamination system. BERAD uses Soil Washing Process by US EPA (402-R-007-004 (2007)) and can decontaminate 0.5 tons of radioactive soil per hour through water washing and/or chemical washing with particle size separation. When contaminated soil is input to BERAD, the soil is selected and washed, and after going through a rinse stage and particle size separation stage, it discharges decontaminated soil separated by sludge of less than 0.075 mm. In this experiment, the concentrations of four general isotopes (A, B, C, and D which are important radioisotopes when soil is contaminated by them.) were analyzed by using ICP-MS to compare before and after decontamination by BERAD. Since BERAD is the commercial-scale pilot system that decontaminates relatively large amount of soil, so it is difficult to test using radioactive isotopes. So important general elements such as A, B, C, and D in soil were analyzed. In the study, BERAD decontaminated soil by using water washing. And the particle size of soil was divided into a total of six particle size sections with five sieves: 4 mm, 2 mm, 0.850 mm, 0.212 mm, and 0.075 mm. Concentrations of A, B, C, and D in the soil particles larger than 4 mm are almost the lowest regardless of before and after decontamination by BERAD. For soil particles less than 4 mm, the concentrations of C and D decreased constantly after BERAD decontamination. On the other hand, the decontamination efficiency of A and B decreased as the soil particle became smaller, but the concentrations of A and B increased for the soil particle below 0.075 mm. As a result, decontamination efficiency of one cycle using BERAD for all nuclides in soil particles between 4 mm and 0.075 mm is about 45% to 65 %.
        8.
        2023.11 구독 인증기관·개인회원 무료
        At domestic nuclear power plant, concrete containers are stored to store waste generated before waste acceptance criteria (WAC) was established. Concrete container store concentrated waste liquid and waste resin. In order to disposal radioactive waste to a disposal site, it is necessary to conduct a characteristic evaluation inside the waste to check whether it satisfies the WAC. Two types of concrete containers are stored: round and square. The round type is filled with one 200-liter drum, and the square type is filled with four 200-liter drums. In the case of a round shape, the top lid is fastened with bolts, so it is possible to collect samples after opening the top lid without the need for additional equipment. However, in the case of a square shape, there is no top lid, and concrete is poured to cure the lid, so the separate equipment for characteristic evaluation is required. It is necessary to install a workstation for sample collection on the top of the concrete container, equipment for coring the top of the concrete container, and a device to prevent concrete dust scattering. Currently, the design of equipment for evaluating the characteristics of concrete containers has been completed, and equipment optimization through mock-up test will be performed in the future.
        10.
        2023.05 구독 인증기관·개인회원 무료
        Decommissioning plan of nuclear facilities require the radiological characterizations and the establishment of a decommissioning process that can ensure the safety and efficiency of the decommissioning workers. By utilizing the rapidly developed ICT technology, we have developed a technology that can acquire, analyze, and deliver information from the decommissioning work area to ensure the safety of decommissioning workers, optimize the decommissioning process, and actively respond to various decommissioning situations. The established a surveillance system that monitors nuclide inventory and radiation dose distribution at dismantling work area in real time and wireless transmits data for evaluation. Developed an evaluation program based on an evaluation model for optimizing the dismantling process by linking real-time measurement information. We developed a technology that can detect the location of dismantling workers in real time using stereovision cameras and artificial intelligence technology. The developed technology can be used for safety evaluation of dismantling workers and process optimization evaluation by linking the radionuclides inventory and dose distribution in dismantling work space of decommissioning nuclear power plant in the future.
        11.
        2023.05 구독 인증기관·개인회원 무료
        The concrete structure of a nuclear power plant is a major safety structure that performs shielding functions to block radioactive materials and radiation, heat removal, and isolation functions. Therefore, concrete structures of nuclear power plants must prove structural safety from immediately after construction to dismantling, and a representative method for this is to investigate compressive strength. The compressive strength and specimen standards of concrete structures are specified in ASTM C 42/C 42M, and samples must be obtained through core drilling in order to collect samples according to this standard. However, commercial equipment requires anchor installation work causes radiation dust generation. Even commercial products have developed equipment that does not require anchor installation work, but it can only be applied to flat walls and cannot be applied to curved walls such as bioshields. To solve this problem, a method of fixing to the scaffolding pipe was designed. The equipment developed based on this method fundamentally blocks the generation of radioactive dust. The vertical position can be adjusted using guide shafts and jack screws, and the horizontal position can be adjusted using scaffolding clamps. In addition, the distance between the installation location and the wall can be adjusted by adjusting the scaffolding clamp location of the device. Lastly, it can be rotated to the left and right, so that even on a curved wall, the sampling position can be performed perpendicular to the wall. Core drills that take specimens for measuring compressive strength use the wet type. Core drilling by wet type in radioactively contaminated concrete leads to the disposal of sludge as radioactive waste. Water supplied during core drilling is scattered in all directions by the rotation of the core drill bit, which causes radiation exposure to workers, so measures must be taken to ensure that the water does not splash and gather in one place. Nileplant Co., Ltd. has developed a sludge collection device that can be used with a core drilling device. It can be inserted into a 4-inch core drill bit to meet the specimen regulations of ASTM C 42/C 42M, and nylon resin was used as a material to withstand friction with water, and the wall of the drainage part was thickened to increase durability. Based on these results, it is expected to be able to work more quickly and safely when collecting core drilling samples of radioactively contaminated concrete or radiation and concrete.
        14.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : High concentrations of particulate matter (PM) are emitted or generated from vehicle emissions in urban roads with dense transient populations. To reduce the effect of PM emission on bus stop users at roadsides, a plan to reduce PM emitted from the roadside must be devised. In this study, an atmospheric environment at a roadside is simulated in a large-scale environment chamber, and a test for reducing PM around the bus stop is conducted by installing a bus stop adapted to a PM reduction system. METHODS : Exhaust gas is injected into the experimental and reference chambers using diesel and gasoline vehicles for roadside airquality simulations. The two vehicles are operated in an idle state without an acceleration operation to emit exhaust gas uniformly, and the initial conditions are achieved by injecting car emissions for approximately 40 min. The initial condition is set to 1 ppm of NOx concentration in the environment chamber. Between the two environment chambers, a bus stop adapted to the PM reduction system is installed in the experimental chamber to conduct a PM reduction experiment pertaining to the air quality around the roadside. The experimental progress is set as the start time of the experiment based on the time at which the initial conditions are achieved; simultaneously, the PM reduction system in the experimental chamber is operated. After the simulation is commenced, the PM concentration, which changes over time, is measured using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) without additional injection of car emissions or pollutants. The HR-ToF-AMS measures the chemical composition of non-refractory PM1.0 (NR-PM1.0) in real time. RESULTS : The NR-PM1.0 compound (organic aerosol (OA), NO3 -, SO4 2-) increases by 160% compared with the simulated initial concentration up to T90min in both environmental chambers; this is speculated to be due to secondary formation. The reference chamber indicates a slight decrease or a steady-state after T90min, whereas the experimental chamber indicates a gradually decrease as the experiment progresses. The bus stop adapted to the PM reduction system reduces the amount of black carbon in the experimental chamber by 37% at 200 min. This implies that the PM emitted from the roadside is filtered via the PM reduction system installed at the bus stop, and cleaner air quality can be provided to passengers. CONCLUSIONS : The PM reduction system evaluated in this study can be detached from and attached to the outdoor billboard of a bus stop. Since it adopts air filtration technology that uses a high-efficiency particulate air filter, it can be maintained and managed easily. In addition, it can provide an atmospheric environment with reduced PM emission to passengers as well as provide a better air-quality condition to passengers waiting for public transportation near roadsides.
        4,000원
        15.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The purpose of this study was to develop the evaluation methodologies for spraying amount and sprayed condition of curing compound based on IoT technology when concrete pavements are constructed. METHODS : To measure the spraying amount of curing compound, a turbine type flowmeter was selected and a number of laboratory experiments were performed to verify the applicability of the selected sensor. To evaluate the uniformity of the sprayed curing compound on the concrete pavement surface, image process technologies were examined using pictures taken from the actual construction sites and from the test specimens. RESULTS : By performing experiments using water and curing compound, the selected flowmeter was verified to properly be applied to measure the spraying amount of curing compound with an acceptable accuracy. By conducting image processing using pictures of the sprayed curing compound on the concrete pavement surface, it was found that the 8 color analysis method was the best to evaluate the uniformity of the sprayed curing compound. CONCLUSIONS : From this study, it was concluded that the spraying amount of curing compound could be accurately measured using a turbine type flowmeter and the uniformity of the sprayed curing compound on the concrete pavement surface could be properly evaluated using an image processing technology.
        4,000원
        16.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : Over the years, the concentration of fine dust is gradually increasing, thereby aggravating the seriousness of the situation. Accordingly, this study intends to install a clean road system using low impact development (LID) techniques on the roadside in order to reduce the scattering of dust on roads effectively. This system stores rainwater collected through gutters in rainy weather and sprays water onto the pavement surface to reduce the scattering of road dust. METHODS : The developed clean road system consists of a water tank, controller, rain detection sensor, and solar cell. Based on this, a test-bed construction was used to evaluate its applicability. By applying the developed system, actual applicability was evaluated through total suspended solid (TSS) test and fine dust measurement. TSS test was conducted to measure the reduction rate of scattering dust on the road owing to the water injected by the clean road system. A spray nozzle was used for the TSS test, and a nebulization nozzle was used for the measurement of fine dust. In order to increase the reliability of the test, three measurements were taken each, for normal road as well as unfavorable conditions road that reproduced the construction site. RESULTS : In this study, fine dust concentration measurement and TSS test were conducted to evaluate the practical applicability of the developed clean road system. From the TSS test, it was found that for both general roads and roads depicting bad conditions, the TSS value after the first spray was the highest, and the value after the second spray was sharply reduced, such that most of the re-dispersed dust was washed out after the first spray, and similar TSS value results were obtained after the third spray. Based on this result, the result of fine dust measurement showed similar fine dust reduction effect of 9%-15.9% regardless of the concentration of fine dust in the atmosphere. These results indicate that the concentration of fine dust in the atmosphere does not significantly affect of the degree of reduction in fine dust. CONCLUSIONS : In this study, a clean road system for reducing fine dust on the road was developed and its applicability was evaluated. In a future study, we intend to check the performance of the drainage pavement through performance evaluation of water permeability coefficient test and performance test in the form of drainage pavement. Through this, we intend to evaluate the applicability of the clean road system to which drainage pavement is applied. Moreover, we will develop a clean road system that applies drainage packaging, and analyzes the degree of fine dust reduction according to the spray angle, spray amount, and spray time of the clean road system in order to study the spray system with the optimum amount of fine dust reduction. In addition, in order to reduce fine dust in the winter, when fine dust is mainly generated, it is planned to install heating wires in spray pipes where freezing is expected. Lastly, the black ice prevention effect will be analyzed by mixing a certain amount of sodium chloride when spraying water.
        4,000원
        18.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        수출입 증명, 위생등급제, 식품 민원처리, 식품 관련 인증, 식품 위해정보 관리 및 식품이력추적 관리제도 등 식품안전관리 시스템에 블록체인 기술도입의 적절성을 효과성과 제약성 평가지표에 따라 전문가 대상 설문조사를 실시하여 평가하였다. 식품안전 업무영역별 블록체인 도입 적절성에 대한 포트폴리오 분석을 진행하여 블록체인 도입 우선순위를 설정하였다. 블록체인 도입 시 효과를 기대할 수 있는 영역은 식품인증, 위생등급제, 위해정보 및 수출입 증명 업무였다. 반면, 이력추적 및 민원처리 업무의 경우 블록체인 도입의 효과성이 낮아 도입대상에서 제외할 것으로 평가되었다. 한편 조사된 6가지의 식품안전관리 업무영역 모두에서 블록체인 도입 시 비용, 법·제도 개정 등 보통 이상의 제약성이 존재하였다. 특히, 식품이력추적관리 분야는 도입 추진 시 가장 제약사항이 많을 것으로 평가되었다. 블록체인 도입 시 수출입 증명 업무의 효과는 높으나 비용과 법 개정 등 제약성이 높아 블록체인 도입을 위해서는 제도개선 등이 필요할 것으로 판단되었다. 평가대상 업무분야들 중 식품인증, 위생등급제 및 위해정보 관련 업무는 블록체인 도입 시 신뢰성과 투명성을 크게 향상시키면서 제약성이 상대적으로 낮아 블록체인을 우선적으로 도입하는데 적합할 것으로 평가 되었다.
        4,000원
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