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        검색결과 238

        42.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The outrigger damper system is a structural system with excellent lateral resistance when a wind load occurs. However, research on outrigger dampers is still in its infancy. In this study, dynamic response control performance of damper is analyzed according to change of stiffness value and damping value of damper. To do this, a real-scale 3D model of 50 stories has been developed and the artificial wind load has been entered for dynamic analysis. Generally, the larger the damping value, the smaller the stiffness value is, the more effective it is to reduce the maximum displacement and acceleration response. However, the larger the attenuation value as the cost of construction increases, it is necessary to select appropriate stiffness and damping value when applying an outrigger damper.
        4,000원
        43.
        2018.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order for the probe to perform ocean exploration and survey research, it is necessary to adjust the position of the ship as desired by dynamic positioning system. The dynamic positioning system of T/S NARA is applied to K-POS dynamic positioning system of Kongsberg, which makes maintaining the ship's position, changing position and heading control possible. T/S NARA is not capable of dynamic positioning if one or more propulsive forces are lost with DP Level One. However, it is predicted that dynamic positioning can be achieved even at the time of missing one thrust in a good sea condition. Therefore, we want to analyze the effect of each propulsion on the performance of dynamic position system. When one of the bow thruster and azimuth thrusters lost their propulsion, maintaining the ship's position, changing position and heading control performance were compared and analyzed. If the situation occurred disable from using the bow thruster, they can not maintain ship's position. Azimuth thruster was influential for the ship's position control and bow thruster was influential in heading control. The excellent dynamic positioning performance can be achieved, considering the propulsion power that will have a impact on each situation in the future.
        4,000원
        44.
        2018.05 구독 인증기관·개인회원 무료
        2012년부터 강화된 총인의 농도를 준수하기 위해서는 응집에 의한 물리화학적 처리가 필수적인 후단공정이 되었으며, 현재 국내 하수처리시설 중 약 60%의 처리시설에서 총인처리시설이 설치되었다. 하지만 총인처리시설 운전에 따른 응집제 사용량이 증가하게 되었고, 이에 따라 약품 비용 및 슬러지 처리비 증가 등의 운영비가 상승하였다. 특히 분리막 공법(MBR)의 경우 막 투과수의 응집액 부족으로 인한 응집효율 저하 및 응집제의 과다 주입으로 인한 처리수질 악화 등의 문제가 발생하는 경우도 있다. 본 연구에서는 MBR 공법내에서 별도의 총인처리시설 필요 없이 생물학적 인제거를 극대화 하는 동시에 응집제 사용량을 최소화하면서 처리수의 인농도를 0.2 mg/L 이하로 유지할 수 있는 방안을 도출하고자 하였다.
        45.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Since the encoder and resolver are expensive, it is difficult to apply it as a position sensor of a motor in a real industrial field. Optical position sensors, such as encoders and resolvers, are also difficult to mount because of their size and durability. Therefore, in order to solve these problems, we propose a system that uses a linear motor as a stator and a magnet plate as a mover, and a system that excludes a separate linear scale and uses two linear Hall sensors and permanent magnets to generate a conventional sine wave, A linear motor capable of detecting an absolute position and a movement position of a magnet, a control method thereof, and a technology development that can reduce a production cost by developing a position control system using a magnet mover that can improve stability and reliability.
        4,000원
        46.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        With the concerns of global climate change, the significant changes in rainfall patterns have aggravated the occurrence of pollutants from agricultural uplands. Heavy and intensive rainfalls have rinsed a variety of pollutants off the land, sending them into the neighboring water environments which further causes water pollution problems. Recently, the application of PAM(Polyacrylamide) in agricultural lands has gotten much attention for soil conditioning. Therefore, this study aimed to develop the automatic control system applying the chemical flocculant, liquid PAM in order to flocculate the suspended solids and deposit at the bottom of farmland water channel, so eventually minimize the amount of non-point pollutants discharged into receiving water. The optimum feed rate for liquid PAM was calculated through the experiment in artificial water channel and applied to the control system. As the results of the performance test of the automatic turbid water control system installed in the sloped field, the range of turbidity reduction rate was 25 to 33% with the average turbidity of 292 to 498 NTU in water channel.
        4,000원
        47.
        2017.11 구독 인증기관·개인회원 무료
        채소의 고정된 절단 형태를 가공할 수 있는 절단기는 실용화되어 국내외에 시판돼 있다. 하지만, 기존 개발된 절단기는 특정 채소류의 절단 작업 시 단일 절단 형태에 국한되어 있고 채소의 절단 형태에 따라 칼날을 교체하여야 하며 사용자의 수동제어에 의존하고 있다. 따라서 본 연구에서는 채소의 종류에 상관없이 절단의 다양한 형태가 가능한 모터 자동제어시스템을 개발한다. 채소 투입 시 흐트러짐 방지를 위한 가압장치와 메인 블레이드 장치를 PWM(Pulse Width Modulation)제어로 펄스의 폭을 조정하여 부하 전력의 크기를 조절한다. 그러하여 기어드 모터의 토크를 유지하면서 속도를 제어한다. 1~25mm 절단 두께를 조절하기 위해서 구동 컨트롤러(펄스 발생기)가 일체형으로 스텝모터 드라이버가 내장되어 있는 리니어 스텝 모터로 선정하였다. 스텝 모터는 프로그래밍을 통한 시그널로 정밀한 각도 및 정밀 위치제어가 가능하고 정지 상태에서 큰 자기 유지력(Holding torque)을 갖는다. 또한, 채소 배출시 이송용 컨베이어 벨트 구동과 속도 제어를 하는데 기존 컨베이어 모터 방식은 모터가 외부에 노출되어 있어 설치나 분해 및 관리에서 애로사항이 발생하는데 드럼 모터는 기어 박스, 체인, 모터 등의 모든 부품들이 일체화되어 있어 기계 배치에 효율적이다. 또한, 물 세척이 가능하고 청소가 용이하여 유지관리에 장점이 있다. PLC로 위치결정 및 이송을 제어하여 전처리 작업의 자동 제어 시스템을 구현하였다. 10인치 터치스크린 패널에서 절단 두께, 속도 조절 및 세척 기능 등을 제어하여 작업자의 편의성 증대 및 작업과정을 모니터링할 수 있다.
        49.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to develop the technology to manage the growth of mushrooms, which were cultivated based on long-term information obtained from quantified data. In this study, hardware that monitored and controlled the growth environment of the mushroom cultivation house was developed. An algorithm was also developed to grow mushrooms automatically. Environmental management for the growth of mushrooms was carried out using cultivation sites, computers, and smart phones. To manage the environment of the mushroom cultivation house, the environmental management data from farmers cultivating the highest quality mushrooms in Korea were collected and a growth management database was created. On the basis of the database value, the management environment for the test cultivar (hukthali) was controlled at 0.5 °C with 3–7% relative humidity and 10% carbon dioxide concentration. As a result, it was possible to produce mushrooms that were almost similar to those cultivated in farms with the best available technology.
        4,000원
        50.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, a winch and load motion control system design method is introduced. Especially, the winch and load (moving cart) are connected with long wire rope which is extended to few kilometers long. Therefore, the rope length changes such that many dynamic parameter values are changed as well by winding and releasing the rope from the winch system. In this paper, the authors designed the control system by considering the real time parameter variation to occupy and keep good control performance continuously. The effectiveness of introduced method was evaluated by simulation results.
        4,000원
        51.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A baggage handling system (BHS) in airport is an unified system for moving the passengers’ baggage in designated time. Input baggage from the check-in counter travels to the baggage claim area or cargo handling terminal through this system. In particular, entryway BHS consists of conveyors, X-ray and sorters such as tilt-tray to send the baggage to departing airplane and it could have various problems for handling certain amount of baggage in restricted time such as baggage jamming at certain merge point. This causes systemic error such as delay of the time, omissions of the baggage and even breakdown of the equipment and inefficiency. Also the increasing maximum time of the baggage passing through the BHS could delay the flight schedule and finally decrease the service level. Thus, the algorithm for controlling the flow of the merge is essential to the system. The window reservation algorithm is the one of the most frequently used methods to control the merge configuration. Above all, the reserve location, so called reserve ahead point, that allocates the window is important for the performance of the algorithm. We propose the modified window reservation algorithm and the best reserve locations by changing the reserve ahead point in the induction conveyors. The effect of various reserve ahead points such as the capacity and utility of the system were analyzed and the most effective reserve ahead point combination was found. The total baggage processing time and the utilization of the tilt-tray are properly considered when choosing the optimal Reserve ahead point combination. In the layout of this study, the configuration of four conveyors merged into one tilt-tray is studied and simulation analysis is done by AutoMod®, 3D simulation software. Through the simulation, the window reservation algorithm is effectively operated with the best combination of reserve ahead point which reduces the maximum baggage travel time.
        4,000원
        52.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The demand for skyscrapers is increasing worldwide. Until now, various lateral resistance structures have been used for lateral displacement control of high-rise buildings. An outrigger damper system has been introduced recently to improve lateral dynamic response control performance further. However, a study of outrigger damper system is yet to be sufficiently investigated. In this study, time history analysis was performed to investigate the control performance of an outrigger damper system of high-rise building under eccentric loading. To do this, an actual scale 3-dimensional tall building model with an outrigger damper system was prepared. The control performance of the outrigger damper system was evaluated by varying stiffness and damping values. On the top floor torsional angle response to the earthquake load, was greatly affected by damping value. And the displacement response was affected greatly by the stiffness value and damping value of damper system. In conclusion, it is necessary to select the proper damping and stiffness values of the outrigger damper system.
        4,000원
        55.
        2017.05 구독 인증기관·개인회원 무료
        산업폐수 처리에서 미량오염물질(독성 유기물, 화합물, 연료 등)의 제거가 중요하다. 생물학적 처리에 의해서는 미량오염물질을 제거하기 어렵다. 따라서 본 연구에서는 분리막과 고도전기산화를 접목하여 색도, 미세입자등을 효과적으로 제거하고 막오염을 저감시키는 막결합형 고도전기산화시스템을 개발하였다. 색도는 원수 120 도(Pt-Co 색도 값)에서 처리수 20 도이하로 제거되었고, 탁도의 경우 처리수 0.1 NTU이하의 수준으로 감소하였다. 또한 막오염 저감의 성능으로 전극을 켜지않고 실험하였을때 16 kPa까지 증가하였으며 0.5 A/L전류를 공급하였을 때 5 kPa으로 유지되었다. 본 연구는 한국환경산업기술원의 환경융합 신기술 개발사업(No. 2015001640004) 연구결과의 일부이다.
        57.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was begun with the object of actively reflection the rapid technological advancements of the electronical control and mechanical control industries to sewage disposal methods. Or focuses on applying a flow control method that utilizes inverters and automatic valves to sewage treatment process systems.This study proposes that sewage treatment process systems architects must acquire a certain degree of technical skills in the areas of electrical and mechanical controls in order to raise the standard of completeness of sewage treatment process systems. And further emphasizes that there is required continuous research on automatics valves that are used in sewage treatment.
        4,000원
        58.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The train-centric control systems development has some distinct points in that a big size of government budget is in general expended in there and the development duration seems to be long. In addition, the changes are ever made continuously in the capability and operational requirements for Trains. Thus, the impact of the potential changes in the required operational capability on the development activities can induce some type of project risks [7]. As such, proper management of project risk has been one of crucial subjects in the train systems development. All these notes combined together make it the significance of the safety management process be raised further up in the train-centric control systems development. As such, the underlying safety management process should be capable of appropriately handling the potential risks that can be created due to the unexpected changes and the long-term development period. The process should also be complemented for the safety consideration of train-centric control systems, for instance, stop. To study these aspect is the objective of the paper. To do so, a step-by-step approach to analyzing the safety management process is first presented. Then, to enhance the process some necessary and useful activities are added in terms of risk and safety management. Then, to pursue some enhancement on the process, a set of necessary and useful activities are added in terms of risk and safety management. The resultant process is further analyzed and tailored using a design structure matrix method. The resultant process is applied in a train-centric control development as a case study.
        4,000원
        59.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent years, an outrigger damper system has been proposed to reduce dynamic responses of tall buildings. However, a study on outrigger damper system is still in its early stages. In this study, time history analysis was performed to investigate the dynamic response control performance of outrigger damper. To do this, a actual scale 3-dimensional tall building model with outrigger damper system has been developed. El Centro earthquake was applied as an earthquake excitation. The control performance of the outrigger damper system was evaluated by varying stiffness and damping values. Analysis results, on the top floor displacement response to the earthquake load, was greatly effected by damping value. And acceleration response greatly was effected by stiffness value of damper system. Therefore, it is necessary to select that proper stiffness and damping values of the outrigger damper system.
        4,000원
        60.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A new design concept for integrated thermal energy storage system is suggested to increase energy saving rate for heating and cooling system of the closed glass greenhouse. Heat pump of air source is installed in the mechanical room and air flows then controlled by damper system located between the greenhouse and outdoor environments. A damper control algorithm is designed to enhance the usage of excessive energy in the glass greenhouse. Since the proposed system is installed at the actual glass greenhouse site for experimental verification of energy savings, the proposed system with damper control is compared with conventional greenhouse heating and cooling system. From results, it is found that more than 10% increase of energy saving rate is achieved.
        4,000원
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