• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.154-156
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• 2007

This paper proposes new control method of maximum power point tracking for the seaflow generation system. This control system is performed by using the duty ratio control of DC/DC converter. An advantage of MPPT(Maximum Power Point Tracking)control method presented in this paper is not necessary to use the seaflow turbine characteristic at various seaflow speed and measure the tidal speed and/or the rotation speed of the seaflow generator. Therefore the resulting system ha s the characteristics of lower cost, higher efficiency and lower complexity. The fuzzy controller is used to control the duty ratio of DC/DC converter. So the reactivity and the reliablilty of the generation system is developed. Proposed control method was analyzed mathematically and tested by computer simulation by using Matlab $Simulink^{(R)}$.

• Proceedings of the ESK Conference
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• 1996.10a
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• pp.160-165
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• 1996

This paper presents the development of video-based 3-dimensional tracking system. Measurement of human motion is important in the application of ergonomics. The system uses advanced direct video measurement technology. Passive retro-reflecting markers are attached to a subject and movements of markers are observed by two CCD cameras. Infrared light emitted near the CCD cameras is reflected by the markers and is detected by the cameras. The image ae captured by Samsung MVBO2 board and the center of markers is calculated by DSP program. The position of markers are transferred from MVB02 board to the computer through AT bus. The computer then tracks the position of each marker and saves the data. This system has dynamic accuracy with 1% error and the sampling rate to 6-10 Hz, and can analyse the trajectory and speed of the marker. The results of this study can be used for operators motion analysis, task analysis, and hand movement characteristic analysis.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.262-265
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• 1999

This paper describes a new method for object extraction necessary for image tracking systems. The extraction method which this paper proposes here is that an M-array is set between a camera and the object and the obtained image including the object and M-array is pro-cessed for extracting the object. The image processing utilizes a characteristic of M-array which is robust to noise. When an M-array is overlapped on the object in background image, the object woud have a part of M-array, which is detected by use of partial correlation between the mosaic image of M-array and the standard M-array. Thus the shape and position of the object are extracted by extracting a common domain of width of high correlation value. Experiments are carried out by using an actual photo of Kumamoto city taken from an airplane as background, and by use of a rectangular and circular object. The results of experiment show a wide application of this method for practical image tracking systems.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.234-237
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• 2003

As the maximum power operating point (MPOP) of photovoltaic (PV) power systems changes with changing atmospheric conditions, the efficiency of maximum power point tracking (MPPT) is important in PV power systems. Many MPPT techniques have been considered in the past, but techniques using microprocessors with appropriate MPPT algorithms are favored because of their flexibility and compatibility with different PV arrays. Although the efficiency of these MPPT algorithms is usually high, it drops noticeably in case of rapidly changing atmospheric conditions. In this paper, we proposed a new MPPT control method called improved perturb and observe method (ImP&O), anda simple voltage and current characteristic equation of a PV array for PV array simulator. Experimental results verify the accuracy and excellent performance of the proposed MPPT method. ImP&O algorithm is very simple, and has successful tracked the MPOP, even in case of rapidly changing atmospheric conditions.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.4
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• pp.34-43
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• 2001

Analysis and control of intake charge motion such as swirl and tumble are very important to improve the performance of gasoline engines. In this paper, single frame double exposure PTV(particle tracking velocimetry) is used to investigate intake flow characteristic in a steady flow test rig of gasoline engine with 2-valve and pent-roof combustion chamber. To validate this PTV method, we confirmed reliability of this PTV method using chopper, and coaxial burner experiments. The velocity Held of intake flow is measured with the intake valve lift variation. It is shown that maximum flow velocity is increased and tumble flow become stronger than inverse tumble flow as valve lift increase.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.225-229
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• 1996

In this study, in order to develop outdoor insulating materials, SIN(simultaneous interpenetrating polymer network) was introduced to Epoxy resin and the environment resistance was investigated. The single network structure specimen(E series) formed of Epoxy resin alone and simultaneous interpenetrating polymer network specimen (EM series) in which epoxy resin was taken as the first network and methyl methacrylate resin as the second network were manufactured. Ten kinds of specimens were manufacture by filler (SiO$_2$) content. SEM were utilized in order to confirm their network structure changes, and AC voltage dielectric strength was measured. Also, UV-test and tracking test were carried out investigate the environment resistance characteristic. Therefore the variations of network structure were happened as a result of SEM test, and it was confirmed that simultaneous interpenetrating polymer network specimens were more excellent than single network structure specimens.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1654-1656
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• 1997

Tracking currents related to field exposure for ADSS in T/L is of importance. At phase-ta-phase voltage in excess of 100 kV self-supporting aerial cables with solid insulation tend to suffer damage in regions close to the tower. The damage can be put down to surface tracking currents resulting from different degrees of surface contamination and moisture. Main characteristic of this exposure is the induced voltage analysis and position of ADSS. For complicated calculation of induced voltage on ADSS, this paper described an effective numerical calculation method based on CSM. The proposed methods are applied to 275 kV T/L of Malaysia.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1813-1815
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• 1997

In this study, in order to develop outdoor insulating materials, SIN(simultaneous interpenetrating polymer network) was introduced to Epoxy resin and the environment resistance was investigated. Six kinds of specimen were manufacture by filler($SiO_2$) content. SEM was untilized in order to confirm their network structure changes. Also, tracking test, UV test and acid rain test were carried out investigate the environment resistance characteristic. Therefore it was confirmed that simultaneous interpenetrating polymer network specimens were more excellent than single network structure specimens. But, acid rain almost never changed resistance.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.11
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• pp.1455-1463
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• 1995

A new automatic tracking & recognition algorithm which decides the opening & the closing states of subject's eye and isn't affected by the subject's background is proposed. And it was tested in circumstances in which subject's background was not restricted using the developed system, ATRS(Automatic Tracking & Recognition System). The significant characteristic of the ATRS is new movement detection of object that is a body in motion with accelated velocity and it doesn't need any extra hardware except a formal CCD camera and an image grabber but it works so well and so fast. The ATRS would be particularly well suited to a way of communications of patients in a hospital, who can not communicate otherwise.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.1
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• pp.29-36
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• 2020

In this study, a variable step algorithm is proposed on the basis of the perturb and observe method. The proposed algorithm can follow the maximum power point (MPP) quickly when solar irradiance changes rapidly. The proposed technique uses the voltage change characteristic at the MPP when the environment changes because of insolation or temperature. The MPP is tracked through the voltage control using a variable step method. This method determines the sudden change of solar irradiance by setting the threshold value and operates in fast tracking mode to track the MPP rapidly. When the operation point reaches the MPP, the mode switches to the variable step mode to minimize the steady state error. In addition, the output disturbance is decreased through the optimization of the control method design. The performance of the proposed MPPT algorithm is verified through simulation and experiment.