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        검색결과 385

        21.
        2023.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Laver aquaculture, which occupies a large proportion in the aquaculture industry in Korea, is still highly dependent on human labor. Therefore, it is necessary to study the development of an automatic system to improve the working environment and increase the efficiency of aquaculture production systems. The purpose of this study is to evaluate the economic feasibility of an improved system in a study for the loading-unloading and automatic weighing systems in laver aquaculture industry. Economic analysis of the developed unloading and automatic weighing system were implemented under various conditions to calculate more accurate benefits and costs. As a result of this study, the economic feasibility was found to be very high in the three models: net present value (NPV), benefit-cost ratio (B/C), internal rate of return (IRR). Moreover, the results of sensitivity analysis showed that the economical efficiency of the automatic loading, unloading, and weighing system in laver aquaculture was very high.
        4,000원
        22.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In wastewater treatment, an emulsion polymer automatic dissolving system is used to mix and dissolve the polymer used as a polymer coagulant with water before it is put into the dissolution tank. In this study, a disperser is developed to mix water and emulsion polymer better in the dissolving system. For this purpose, the flow analysis of the three disperser models was performed to select the disperser for the emulsion polymer automatic dissolving system with the best performance. The excellence of mixing was evaluated by grasping the flow uniformity and the vorticit in the disperser, and it was confirmed that the TYPE3 disperser was excellent.
        4,000원
        24.
        2023.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This study examined effects of pronunciation training using automatic speech recognition technology on common pronunciation errors of Korean English learners. Participants were divided into two groups. One group was given instruction and training about the use of automatic speech recognition for pronunciation practice. The other group was not given such instruction or training as a control group. A pre- and post-test experimental design was used. The treatment period was four weeks. Participants who were taught about using automatic speech recognition for pronunciation practice showed small but significant improvements in pronunciation accuracy than those who did not. In addition, automatic speech recognition was found to assist in the diagnostic evaluation of common pronunciation errors, although it did not produce statistically significant improvements. Participants responded positively to the use of automatic speech recognition for pronunciation practice and testing, although there remain some concerns over technical aspects of the test.
        5,700원
        25.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the second-order Nomoto’s nonlinear expansion model was implemented as a Tagaki-Sugeno fuzzy model based on the heading angular velocity to design the automatic steering system of a ship considering nonlinear elements. A Tagaki-Sugeno fuzzy PID controller was designed using the applied fuzzy membership functions from the Tagaki-Sugeno fuzzy model. The linear models and fuzzy membership functions of each operating point of a given nonlinear expansion model were simultaneously tuned using a genetic algorithm. It was confirmed that the implemented Tagaki-Sugeno fuzzy model could accurately describe the given nonlinear expansion model through the Zig-Zag experiment. The optimal parameters of the sub-PID controller for each operating point of the Tagaki-Sugeno fuzzy model were searched using a genetic algorithm. The evaluation function for searching the optimal parameters considered the route extension due to course deviation and the resistance component of the ship by steering. By adding a penalty function to the evaluation function, the performance of the automatic steering system of the ship could be evaluated to track the set course without overshooting when changing the course. It was confirmed that the sub-PID controller for each operating point followed the set course to minimize the evaluation function without overshoot when changing the course. The outputs of the tuned sub-PID controllers were combined in a weighted average method using the membership functions of the Tagaki-Sugeno fuzzy model. The proposed Tagaki-Sugeno fuzzy PID controller was applied to the second-order Nomoto’s nonlinear expansion model. As a result of examining the transient response characteristics for the set course change, it was confirmed that the set course tracking was satisfactorily performed.
        4,200원
        26.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        스마트농업의 활성화를 위해서는 농업환경 데이터의 관측과 모델 그리고 통계자료의 상호운영성 확보가 중요하므로, 이를 위한 격자체계의 적용방안을 탐색하고자 한다. 국내외 격자체계 표준에 대한 사례조사와 농업분야의 격자표준 적용사례조사를 벤치마킹하고 국립농업과학원과 상위기관의 표준현황을 살펴보고, 농업환경 공간정보의 목록과 분류체계를 구축한 후, 사용자 요구사항을 파악하기 위한 설문을 실시하여 적정한 격자 크기를 선정하였다. 농업환경 공간정보의 공유와 활용을 위하여 국토지리 정보원의 기관표준을 차용하여 군 이하 소규모 지역은 10m, 광역시・도는 100m, 농촌경관 목적으로는 500m, 전국은 1km 격자 크기로 안을 제시하였고 원활한 표준 적용을 위한 전략을 제안하고, 현장 조사 및 관측 결과를 격자로 변환할 수 있도록 오픈소스 기반의 변환 툴을 개발하여 격자표준 적용 용이성과 시간 절약성을 확보하였다.
        4,800원
        31.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 자동계류 장치에 설치하여 선박의 접안 상황을 검출할 수 있는 시각 센서의 개발에 대하여 논하고 있다. 선박의 접 안 시 사고방지를 위해 선박의 속도를 통제하고 위치를 확인하고 있음에도 불구하고 부두에서의 선박 충돌사고는 매년 발생하고 있으며, 이로 인한 경제적, 환경적 피해가 매우 크다. 따라서 부두에 접안하는 선박에 대한 안전성 확보를 위해 선박의 위치 및 속도 정보를 신속 하게 확보할 수 있는 시각 시스템의 개발은 중요하다. 이에 본 연구에서는 선박의 접안 시 사람과 유사하게 영상을 통해 접안하는 선박을 관찰하고, 주변 환경에 따른 선박의 접안 상태를 적절하게 확인할 수 있는 시각센서를 개발하였다. 먼저, 개발하고자 하는 시각 센서의 적 정성을 확보하기 위해 기존 센서로부터 제공되는 정보, 감지 범위, 실시간성, 정확도 및 정밀도 측면에서 센서 특성을 분석하였다. 이러한 분석 자료를 바탕으로 LiDAR형태의 3D시각 시스템의 개념 설계, 구동메커니즘 설계 및 모션 구동부의 힘과 위치 제어기 설계 등을 수행 하여 대상물의 정보를 실시간으로 획득할 수 있는 3D 시각 모듈을 개발하였다. 최종적으로 시스템 구동을 위한 제어 시스템의 성능평가 와 스캔 속도에 대한 성능을 분석하였고, 실험을 통해 개발된 시스템의 유용성을 확인할 수 있었다.
        4,000원
        32.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The existing production and manufacturing process was manually operated and the cleaning process was not constant due to poor environmental conditions for several hours, so the production efficiency was significantly lowered and manufacturing cost was increased. In this R&D, productivity improved by doubling the production of 300 units per hour to 700 units, and in this development, manufacturing costs were lowered through this process improvement project based on automotive shoba automation technology.
        4,000원
        33.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The global power generation industry is becoming a key power generation industry with gas power generation and renewable energy solar power generation. This research aims to focus on solving two problems as a method to improve the solar light collection efficiency among fixed variable deformation methods. Maintaining the proper temperature of the water injection device through automatic temperature detection to solve efficiency degradation, and establishing an automatic operation system by finding the optimal angle for each season, are intended to derive a value that can represent the optimal power generation.
        4,000원
        34.
        2022.10 구독 인증기관·개인회원 무료
        To efficiently manage the waste packages like drums, it is meaningful to utilize the data of placement and emplacement of disposed waste in geological storage. For the transparent and real-time management of disposal data, both technical as well as administrative factors must be included. To this end, MIRAE-EN Co., Ltd. has developed a radioactive waste tracking and management system (m-trekⓇ v1.0) through radioactive waste management life cycle which is supported by KETEP. Enhancing the functional features of m-trekⓇ, IoT-based drum location measuring and data of those drums, such as position, radionuclides, activity, and dose etc., are to be collected and monitored through data modeling and visualization, which might be utilized in emplacing the loaded drums according to specifically certain criteria of internal and external data of disposal site. Position measuring using Beacon utilizes Received Signal Strength Indicator (RSSI) to locate the correct position in 3D area. Since RSSI is affected by the surrounding environment, it is required to corrective optimization. In addition, error and deviation of previously applied Gaussian filter method, was corrected and improved through AI learning model. According to this location information and those data, the prototype in future provides the visualization of drum position and its relevant data for administrative purpose such as monitoring, emplacement and other management policy.
        35.
        2022.10 구독 인증기관·개인회원 무료
        For countering nuclear proliferation, satellite imagery is being used to monitor suspicious nuclear activities in inaccessible countries or regions. Monitoring such activities involves detecting changes over time in nuclear facilities and their surroundings, and interpreting them based on prior knowledge in terms of nuclear proliferation or weaponisation. Therefore, analysts need to acquire and analyze satellite images periodically and have an understanding of nuclear fuel cycle as well as expertise in remote sensing. Meanwhile, as accessibility of satellite information has been increasing and accordingly a large amount of high-resolution satellite images is available, a lack of experts with expertise in both fields to perform satellite imagery analysis is being concerned. In this regard, the Institute of Korea Nonproliferation and Control (KINAC) has developed a prototype of semi-automatic satellite imagery analysis system that can support monitoring of potential nuclear activities to overcome the limitations of professionals and increase analysis efficiency. The system provides a satellite imagery database that can manage acquired images, and the users can load images from the database and analyze them in stages. The system includes a preprocessing module capable of resizing, correcting and matching images, a change detection module equipped with a pixel-object-based change detection algorithm for multi-temporal images, and a module that automatically generates reports with relevant information. In particular, this system continuously updates open-source information database related to potential nuclear activities and provides users with an integrated analytics platform that can support their interpretation by linking related images and textual information together. As such, the system could save time and cost in processing and interpreting satellite images by providing semi-automated analytic workflows for monitoring potential nuclear activities.
        37.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: A spinal extension and intensive rehabilitation program reduced the symptoms and pain of kyphosis, and improved function. Objects: This study aimed to demonstrate the effect of a spine extension device on the degree of thoracic kyphosis and extension angles, confirm reduction of the kyphosis angle and an increase in flexibility. Methods: Thirteen adults were enrolled in the experiment, using the spine extension device, which was set to passively extend the spine. The angle between the spinous process of the first thoracic vertebra and the spinous process of the twelfth thoracic vertebra was measured by dual inclinometer before and after using the spine extension device. Results: In the static posture, the thoracic kyphosis decreased after using the spine extension device in the thoracic extension posture, and there was a significant difference (p < 0.05); thoracic extension angle increased with statistical significance (p < 0.05). Conclusion: In this study, the thoracic kyphosis angle and thoracic extension angle of the subjects before and after using spine extension device was compared and analyzed, which proved that the spine extension device can effectively improve the mobility of spinal extension.
        4,000원
        39.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, a two-stage electrostatic precipitator (ESP) was developed using a novel automatic dry cleaning device to reduce the ultrafine particles in subway stations. Collection efficiency was evaluated with a pilot scale ESP (1.2m× 1.2m) and the scale of the test duct was half of the subway air handling unit. The maximum collection efficiency for 0.3 μm particles was 96.9%. In addition, we studied a method of automatic dry cleaning for maintenance of the ESP. The cleaning efficiency was analyzed according to the cleaning flow rate for each particle loading amount to achieve a recovery rate over 90%. In addition, we derived the equation to estimate the reduction in collection efficiency according to the particle loading amount. It was confirmed that the performance of the contaminated ESP was restored to the initial state by the automatic dry cleaning in this study and that the electrical energy consumption was 5 times lower compared to utilizing conventional water cleaning.
        4,200원
        40.
        2022.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the removal efficiency of PFCs(perfluorinated compounds) in the GAC(granule activated carbon) process based on the superheated steam automatic regeneration system was investigated in laboratory scale and pilot-scale reactor. Among PFCs, PFHxS(perfluorohexyl sulfonate) was most effectively removed. The removal efficiency of PFCs was found to be closely related to the EBCT, and the removal efficiencies of PFOA(perfluorooctanoic acid), PFOS(perfluorooctyl sulfonate), and PFHxS were 43.7, 75, and 100%, respectively, under the condition of EBCT of 6 min. Afterward, PFOA, PFOS, and PFHxS exhibited the earlier breakthrough time in the order. After that, GAC was regenerated, and the removal efficiency of the PFCs before and after regeneration was compared. As a result, it was shown that the PFCs removal efficiency in the regenerated GAC process were higher, and that of PFOA was improved to 75%. The findings of this study indicate the feasibility of the superheated steam automatic regeneration system for the stable removal of the PFCs, and it was verified that this technology can be applied stably enough even in field conditions.
        4,600원
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