• Journal of Biosystems Engineering
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• v.26 no.6
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• pp.535-544
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• 2001

This study developed a manipulator for robotic harvester to harvest cucumber. The manipulator was designed and built fur transferring an end-effecter from a fixed point to a specified cucumber. Its development involved the integration of a manipulating system with a PC compatible, DC motors, geared boxes, timing belts, and a motor controller board. Software, written in Quick basic. combined the functions of motor control with various circumstances. In order to move smoothly and rapidly the manipulator, it's shoulder link and elbow link were minimized by using rotational inertial moment without a motor and a geared box. After 30 replications of exercising the manipulator, it was concluded that the precision values of the X, Y and Z axes were less than 0.5mm, 7.25mm and 0.35mm, respectively. The precision data indicated the manipulator was not missing any steps fur the harvester to reach a target cucumber.

• ETRI Journal
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• v.22 no.1
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• pp.20-29
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• 2000

In this paper, we present a design of video and audio single chip encoder/decoder for portable multimedia application. The single-chip called as video audio signal processor (VASP) consists of a video signal processing block and an audio single processing block. This chip has mixed hardware/software architecture to combine performance and flexibility. We designed the chip by partitioning between video and audio block. The video signal processing block was designed to implement hardware solution of pixel input/output, full pixel motion estimation, half pixel motion estimation, discrete cosine transform, quantization, run length coding, host interface, and 16 bits RISC type internal controller. The audio signal processing block is implemented with software solution using a 16 bits fixed point DSP. This chip contains 142,300 gates, 22 Kbits FIFO, 107 kbits SRAM, and 556 kbits ROM, and the chip size is $9.02mm{\times}9.06mm$ which is fabricated using 0.5 micron 3-layer metal CMOS technology.

• Fashion & Textile Research Journal
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• v.11 no.1
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• pp.121-129
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• 2009

Nowadays, global interest is being placed on research and development of smart clothing which is expected to create a high added-value industry in the future. The purpose of this research is to develop smart pants with vibrating massage functions that have excellent outer appearances and provide comfort to wearers and assess outer appearance, comfort, and massaging effects of smart pants. As the results of this research, smart pants where vibrating devices which are mainly composed of vibrating motor, controller, and switch are attached were completed. Vibrating motors were fixed on a thin and light non-woven fabric material, covered with a mesh material, and attached by snaps to the experiment pants. Switch was attached to the inside of a pocket, and batteries were positioned inside of pockets. Ten subjects marked their satisfaction of wearing smart pants on a 5-point scale. Noticeable changes in outer appearance when vibrating motors operate turned out to be low. Wearer's comfort in back waist and front thigh parts where vibrating motors were attached turned out to be high-satisfied. Massaging effects of smart pants turned out to be high. Attaching and detaching vibrating devices turned out to be convenient. Lining materials used for smart paints were effective in blocking electromagnetic waves generated from vibrating devices.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.5
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• pp.583-591
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• 2007

This paper reports the performance of a 150W PV-wave hybrid system with battery storage in buoy. This system was originally designed to meet a new hybrid ower system for buoy in Korea. In the case or lighted buoys and lighthouses, a light failure alarm system of wireless radio is attached so that light failures are immediately notified to the office. At lighthouse offshore fixed lights and light buoys where commercial electricity is not available, the power source depends on solar system and batteries. This power system has a various problems. Therefore energy derived from the sunshine, wind and waves has been used as the energy source lot aids to navigation. Recently a hybrid system of combining the solar, wind and the wave generator is a favorable system lot the ocean facilities like lighthouse and buoy. The hybrid system in this paper is intended for variable DC load like light, communication system in the buoy and includes a PV-wane generation system and battery. This is composed a high efficiency charging algorithm, switching converter and controller. This paper includes discussion on system reliability, power quality, and effects of hybrid system in the buoy. Simulation and experimental results show excellent performance.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.1
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• pp.81-88
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• 2007

In this paper, a new single-phase utility-interactive inverter system for residential power generation with fuel cell is proposed. The proposed inverter system is not only capable of working in both stand-alone and grid-connected mode, but also ensures smooth and automatic transfer between the two modes of operation. The proposed control method has little steady-state error and good transient response characteristic. Also, the control method can be implemented using low-cost, fixed point DSP since it has simpler structure, smaller amount of calculation, and smaller number of sensors. The controller for the proposed utility-interactive inverter system is described, and the validity is verified through simulation and experiment.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.6
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• pp.633-641
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• 2015

Several complex processes that are employed in industries, such as shipping, power plants, and the petrochemical industry, involve time-varying behavior as well as strong nonlinear behavior during operation. The fixed-parameter proportional-integral-derivative (PID) controllers have difficulty in dealing with control problems that occur in such processes. In this paper, we propose a method of designing a nonlinear PID controller for industrial processes that exhibit a large number of nonlinearities and time-varying behavior. The gains of the nonlinear PID controller are characterized by a simple nonlinear function of the error and/or error rate depending on the process set-point and output. We tune the user-defined parameters using a genetic algorithm by minimizing the integral of time absolute error (ITAE) index. We verify the effectiveness of the proposed method by performing a comparison of the proposed method and two other nonlinear and adaptive methods that are employed for reference tracking, disturbance-rejection performances, and robustness to parameter changes on a continuously stirred tank reactor.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.351-358
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• 2016

An Electrical Point Machine (NS:New-type Switch), which is equipped and operated at railways in Korea, has been used since the 1960s after being imported from Japan. On the other hand, although the mechanical configuration has improved the position motor control circuit, the electrical connection has not been improved, so NS may have a problem, such as the interlocking system of automatic train operation. In addition, NS is the most vulnerable part in the railway system and a huge train accident may occur due to minor defects. The existing NS wiring set of the circuit controller should be checked only if fixed. Therefore, an excessive inspection time only by a Railroad Signal expert is required. In this paper, the improvement of electrical connection in a NS wiring set, such as the position motor control circuit, was developed and the prototype was installed at Seoul Metro in the distance to go section. The results can be used to help make appropriate adjustments. The improvement of the NS wiring set enhance the maintenance efficiency, passenger service and the stability of the signal system as well as reducing the maintenance cost.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.3
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• pp.88-97
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• 2013

This paper presents a robust air-to-fuel ratio (AFR) control algorithm for managing exhaust gas recirculation (EGR) systems. In order to handle production tolerance, deterioration and parameter-varying characteristics of the EGR system, quantitative feedback theory (QFT) is applied for designing the robust AFR control algorithm. A plant model of EGR system is approximated by the first order transfer function plus time-delay (FOPTD) model. EGR valve position and AFR of exhaust gas are used as input/output variables of the plant model. Through engine experiments, parameter uncertainty of the plant model is identified in a fixed engine operating point. Requirement specifications of robust stability and reference tracking performance are defined and these are fulfilled by the following steps: during loop shaping process, a PID controller is designed by using a nominal loop transmission function represented on Nichols chart. Then, the frequency response of closed-loop transfer function is used for designing a prefilter. It is validated that the proposed QFT-based AFR control algorithm successfully satisfy the requirements through experiments of various engine operating points.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.3
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• pp.49-58
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• 2000

This paper deals with a systematic approach to neural network controller design for static VAR compensator (SVC) using a learning algorithm of error back propagation that accepts error and change of error as inputs, the momentum learning technique is used for reduction of learning time, to improve system stability. A SVC, one of the Flexible AC Transmission System(FACTS), constructed by a fixed capacitor(FC) and a thyristor controlled reactor(TCR), is designed and implemented to improve the damping of a synchronous generator, as well as controlling the system voltage.TO verify the robustness of the proposed method, we considered the dynamic response of generator rotor angle deviation, angular velocity deviation and generator terminal voltage by applying a power fluctuation and rotor angle fluctuation in initial point when heavy load and normal load. Thus, we prove the usefulness of proposed method to improve the stability of single machine-infinite bus with SVC system.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.2
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• pp.27-34
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• 2014

Buzz margin scheduling and control technique which are suitable to regulate stable and high pressure air in wide range of Mach number are suggested for fixed geometry of a supersonic intake. From the analysis of preceding study, most effective control variable is induced and scheduling law is newly suggested in a real application point of view. The appropriateness of the control law in wide range of Mach number is addressed by numerical simulation of controlled propulsion system. Also, the simulation for stabilization and tracking performances of the controller are studied to investigate the phenomena under flight maneuver and disturbances.