• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1861-1867
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• 2010

This paper described the positioning algorithm of partial discharge in insulation oil by acoustic method for the application of an on-line diagnosis in oil-immersed transformers. In the experiment, five AE sensors having the resonant frequency of 150 kHz were used, and a signal conditioner was fabricated. A needle-plane electrode system which is composed of a needle with a curvature radius of $10{\mu}m$ and a plane electrode with a diameter of 60 mm was installed to simulate partial discharges in insulation oil. From the time difference of arrival (TOA) of acoustic signal, we calculated the location of partial discharge in insulation oil. In the experiment, an algorithm of positioning of PD occurrence by the time difference of arrival was proposed. From the experimental results, the positioning error of PD calculated by three AE sensors was within 4%.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권4호
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• pp.172-177
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• 2006

During normal machine operation, partial discharge(PD) tests were performed with partial discharge analyzer(PDA) in two hydrogenerators. Six cable couplers were installed in circuit ring bus and endwinding of three phases. PDA showed that the normalized quantity number(NQN) and the partial discharge magnitude$(Q_m)$ were very low in hydrogenerator #1 and #2, respectively. The trend analyses of NQN and $Q_m$ value are available for monitoring of the insulation condition in hydrogenerator stator windings. The insulation condition of stator winding can be assessed. Discharge at conductor surface was discovered in B phase(C2 coupler) of hydrogenerator #1. Internal discharges were generated in A and C phases(C2 coupler) of hydrogenerator #1 and in A, Band C phases(C1 and C2 couplers) of hydrogenerator #2. Slot discharges occurred in A, Band C phases(C1 coupler) of hydrogenerator #1. The stator windings of two hydrogenerators were in good condition.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권4호
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• pp.184-191
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• 2001

This paper proposes a prefilter type velocity compensating control system using modified chaotic neural networks for the trajectory control of robotic manipulator. Since the structure of modified chaotic neural networks(MCNN) and neurons have highly nonlinear dynamic characteristics, MCNN can show the robust characteristics for controlling highly nonlinear dynamics like robotic manipulators. For its application, the trajectory controller of the three-axis robot manipulator is designed by MCNN. The MCNN controller acts as the compensator of the PD controller. Simulation results show that learning error decrease drastically via on-line learning and the performance is excellent. The MCNN controller showed much better control performance and shorter calculation time compared to the RNN controller, Another advantage of the proposed controller could by attached to conventional robot controller without hardware changes.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1472-1473
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• 2006

During normal machine operation, partial discharge(PD) measurements were peformed with turbine generator analyzer(TGA) in two high voltage motors(rated 6.6 kV). These high voltage motors were installed with 80 pF capacitive couplers at the terminal box. TGA summarizes each plot with two quantities such as the normalized quantity number(NQN) and the peak PD magnitude (Qm). The trend analyses of NQN and $Q_m$ value are available for monitoring of the insulation condition in stator windings of high voltage motors.

• Transactions on Control, Automation and Systems Engineering
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• 제4권1호
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• pp.38-42
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• 2002

Conditions are discussed for operating a dissymmetric human master-small (or micro) slave system in best (large position gain-small velocity gain) conditions allowing higher operator dexterity when real effects (joint compliance, link flexion delay and transmission distortion) are taken into account. It is shown that position PD feedback law advantage for ideal case no longer holds, and that more complicated feedback law depending on real effects has to be implemented with adapted transmission line. Drawback is slowdown of master slave interaction, suggesting to use more advanced predictive methods for the master and more intelligent control law for the slave.

• 전기학회논문지
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• 제67권6호
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• pp.773-781
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• 2018

In recent years, a study of power-line inspection using an unmanned aerial vehicle (UAV) has been actively conducted. However, relevant studies have been conducting power-line inspection with an UAV operated by manual control, and they have developed just power-line detection algorithm on aerial images. To overcome limitations of existing research, we propose a drone-based power-line tracking system in this paper. The main contributions of this paper are to operate developed system under configured environment and to develop a power-line detection algorithm in real-time. Developed system is composed of the power-line detection and the image-based tracking control. To detect a power-line in real-time, a region of interest (ROI) image is extracted. Furthermore, clustering algorithm is used in order to discriminate the power-line from background. Finally, the power-line is detected by using the Hough transform, and a center position and a tilt angle are estimated by using the Kalman filter to control a drone smoothly. We design a position controller and an attitude controller for image-based tracking control, and both controllers are designed based on the proportional-derivative (PD) control method. The interaction between the position controller and the attitude controller makes the drone track the power-line. Several experiments were carried out in environments where conditions are similar to actual environments, which demonstrates the superiority of the developed system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1936-1938
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• 2004

In this paper, we discussed measurement method of PD (Partial Discharge) of 22.9[kV] cable. Cable rail track laying portable detector that can detect partial discharge of cable connection ashes by on-line done spot way to detect Lemke equipment and high broadcasting CT sensor that use antenna sensor using ICM mounting was explained. Because measurement corona signal is very big, analysis of partial discharge is difficult state, we used connector. It could be attenuated by 2 times. We found out that corona signal which generated on B phase is flowed on A phase and C phase. It could measure that partial discharge of A phase happens actually. We could confirm that partial discharge of about 250 ${\sim}$ 300 [pC] on A phase is dangerous.

• Journal of Gastric Cancer
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• 제23권1호
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• pp.207-223
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• 2023

Gastric cancer (GC) is the fourth leading cause of cancer-related deaths worldwide. Under the standard of care, patients with advanced GC (AGC) have a median survival time of approximately 12-15 months. With the emergence of immunotherapy as a key therapeutic strategy in medical oncology, relevant changes are expected in the systemic treatment of GC. In the phase III ATTRACTION-2 trial, nivolumab, a monoclonal anti-programmed cell death 1 (PD-1) antibody, as a third- or later-line treatment improved overall survival (OS) compared with placebo in patients with AGC. Furthermore, nivolumab in combination with 5-fluorouracil and platinum as a first-line treatment improved OS in patients with human epidermal growth factor receptor-2 (HER2)-negative AGC in the global phase III CheckMate-649 study. Another anti-PD-1 antibody, pembrolizumab, in combination with trastuzumab and cytotoxic chemotherapy as a first-line treatment, significantly improved the overall response rate in patients with HER2-positive AGC. Therefore, immune checkpoint inhibitors (ICIs) are essential components of the current treatment of GC. Subsequent treatments after ICI combination therapy, such as ICI rechallenge or combination therapy with agents having other modes of action, are being actively investigated to date. On the basis of the success of immunotherapy in the treatment of AGC, various clinical trials are underway to apply this therapeutic strategy in the perioperative and postoperative settings for patients with early GC. This review describes recent progress in immunotherapy and potential immunotherapy biomarkers for GC.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1894-1896
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• 2003

In this paper, a novel monitoring system, data acquisition & diagnosis unit (DADU), for high-voltage rotating machines is proposed. This system monitors the insulation condition, current, voltage, vibration, and temperature of the stator winding by on-line measurements of partial discharge (PD), flux, etc. This helps more efficient operation and maintenance of the rotating machines.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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• pp.112-116
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• 2004

On-line monitoring of fault discharge is an important approach for indicating the condition of electrical insulation of stator winding in high voltage motor. In this paper, several key aspects of on-line monitoring system are discussed, involving the characteristics of fault discharge of stator winding in high voltage motor, spectrum analysis of four simulation fault signals, feature extraction of internal fault discharge from apply voltage to breakdown. The study of the partial discharge activities allows to highlight the ageing stage in the winding fault under test. During the life of the winding insulation fault, the shape of PD signal change relating to the ageing stage. The ageing of stator winding insulation fault of high voltage motor is investigated based on the characteristics of partial discharge pulse distribution and statistical parameters, such as maximum, skewness and kurtosis using discrete wavelet transform coefficients.