• Proceedings of the KIEE Conference
• /
• 2002.07c
• /
• pp.1674-1676
• /
• 2002

In this paper, High Frequency PD measuring system using directional coupler sensors(DCS) is introduced. Especially the principles of the DCS and characteristics of the system are introduced. Evaluation of this system was carried by an adoption to the test circuit of 345kV XLPE $2000mm^2$ cable and EB-A, EB-G, PIJ, PNJ. In the test a PD measurement was carried out without shieldroom and under the on-line state and in the high frequency range at the remote site from the test object. The test result was satisfactory and this is due to the use of DCS and using a high frequency range and specific filter for radio and TV signal and low pass. This system can be used to the test of a new construction of cable and accessories and measuring of long-term deterioration of cable and accessories. And this will bring us the reliability of a power transmission.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.11 no.4
• /
• pp.203-207
• /
• 2011

LED is in the spotlight as next generation's lighting due to the fact that it has good efficiency on converting electricity to light and has long life time. Recently it expands the scope up to taillight of car, signal lamp and indoor light. Additionally it can send data information simultaneously with lighting, which is called lighting-communication convergence. In this paper, the channel characteristics of LED wireless communication is studied in the condition that indoor is latticed with 1mm span and photons started from LED are firstly arrived at each lattice after that these move as straight line before meeting photodiode(PD).

• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.36 no.1
• /
• pp.113-124
• /
• 2020

The purpose of this study is to suggest an improvement for the CPTED(Crime Prevention Through Environmental Design) guidelines for the urban linear park. We analysed the Changjeon-dong section of Gyeongui Line Forest Park into 12 sub-areas and evaluated CPTED design applied on the park based on analysis framework derived from 15 precedent studies by conducting on-site observations. Both surveys and in-depth interviews on users of the park were conducted and the results of analysis on the evaluation from users and the on-site observation were compared. We found that the lighting condition and the height of wall and trees at the park boundaries are very important to insure natural surveillance since the adjacent areas are easy to be hidden from passers-by and subject to invasion and threat of crime while protecting the privacy of residents on the boundary. There should be improvement on management facilities and crime prevention facilities for more safe and convenient use of the linear park and the adjacent commercial use during nighttime also need to be managed for conflicts between various type of users.

• ETRI Journal
• /
• v.38 no.5
• /
• pp.981-987
• /
• 2016

We present a cost-effective dual polarization quadrature phase-shift coherent receiver module using a silica planar lightwave circuit (PLC) hybrid assembly. Two polarization beam splitters and two $90^{\circ}$ optical hybrids are monolithically integrated in one silica PLC chip with an index contrast of $2%-{\Delta}$. Two four-channel spot-size converter integrated waveguide-photodetector (PD) arrays are bonded on PD carriers for transverse-electric/transverse-magnetic polarization, and butt-coupled to a polished facet of the PLC using a simple chip-to-chip bonding method. Instead of a ceramic sub-mount, a low-cost printed circuit board is applied in the module. A stepped CuW block is used to dissipate the heat generated from trans-impedance amplifiers and to vertically align RF transmission lines. The fabricated coherent receiver shows a 3-dB bandwidth of 26 GHz and a common mode rejection ratio of 16 dB at 22 GHz for a local oscillator optical input. A bit error rate of $8.3{\times}10^{-11}$ is achieved at a 112-Gbps back-to-back transmission with off-line digital signal processing.

• Proceedings of the KIEE Conference
• /
• 2004.11a
• /
• pp.101-103
• /
• 2004

본 연구는 전력 계통에 상용화된 $SF_6$ GIS(Gas Insulated Switchgear) 내부에서 발생되는 부분방전 검출 방법을 개발하기 위하여, GIS의 내부에 유입되거나 생산과정에서 형성 될 수 있는 세 가지 결함들을 연구용 GIS 내부에 모의하였으며 또한 특성이 다른 센서(UHF, CT, AE)를 제작 또는 이용하여 그 부분방전 패턴 결과와 주파수 분석 결과를 상호 비교하였다. 실험결과에 의하면, 동일한 결함에 의하여 센서의 검출 결과는 다르게 나타나거나 전혀 검출이 되지 않음이 밝혀졌다. 따라서, 부분방전 패턴분석을 하나의 분석방법에 의존하는 것은 바람직하지 못한 것으로 사료되며 신뢰성 있는 GIS 진단을 위하여 적합한 센서개발 및 두 가지 이상의 분석 방법이 병행되는 것이 절대적으로 필요한 것으로 사료된다.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.12
• /
• pp.6017-6022
• /
• 2012

Background: Resveratrol has been reported to have potential chemopreventive and apoptosis-inducing properties in a variety of tumor cell lines. Objective: In this study, to investigate the effects of resveratrol on protein kinase C (PKC) activity and apoptosis in human colon carcinoma cells, we used HT-29 cells and examined the $PKC{\alpha}$ and ERK1/2 signaling pathways. Methods: To test the effects of resveratrol on the growth of HT-29 cells, the cells were exposed to varying concentrations and assessed with the the MTT cell-viability assay. Fluorescence-activated cell sorter (FACS) analysis was applieded to determine the effects of resveratrol on cell apoptosis. Western blotting was performed to determine the protein levels of $PKC{\alpha}$ and ERK1/2. In inhibition experiments, HT-29 cells were treated with G$\ddot{o}$6976 or PD98059 for 30 min, followed by exposure to $200{\mu}M$ resveratrol for 72 h. Results: Resveratrol had a significant inhibitory effect on HT-29 cell growth. FACS revealed that resveratrol induced apoptosis. Western blotting showed that e phosphorylation of $PKC{\alpha}$ and ERK1/2 was significantly increased in response to resveratrol treatment. Pre-treatment with $PKC{\alpha}$ and ERK1/2 inhibitors (G$\ddot{o}$6976 and PD98059) promoted apoptosis. Conclusion: Resveratrol has significant anti-proliferative effects on the colon cancer cell line HT-29. The PKC-ERK1/2 signaling pathway can partially mediate resveratrol-induced apoptosis of HT-29 cells.

• Journal of Korean Port Research
• /
• v.14 no.3
• /
• pp.291-301
• /
• 2000

T his paper presents the lateral and longitudinal control algorithm for the driving of a 4WS AGV(Automated Guided Vehicle). The control law to the lateral and longitudinal control of the AGV includes adaptive agin tuning ability, that is the controller gain of the gravity compensated PD controller can be changed on a real-time. The gain tuning law is derived from the Lyapunov direct method using the output error of the reference model and the actual model, And to show the performance of the presented lateral and longitudinal control algorithm, we simulate toe nonlinear AGV equations of the motion by deriving the Newton-Euler Method, The read path is from quay yard area to docking position in loading yard area. The quay yard area is where the quay crane loads the container to the AGV and the docking position is where the container is transferred to the gantry crane. The road types are constructed in a straight line and J-turn. When driving the straight line, the driving velocity is 6㎧ and the J-turn is 3㎧.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.8 no.5
• /
• pp.76-82
• /
• 1999

During operating given working a robot manipulator makes some problems such as the accumulation of the error or the deviation from the command trajectory. These problems are mainly due to the disturbance noise or unmodeled system parameters. To solve these problems most of robot manipulators equip the controller. But if exact controller gains are not seleced we can't decrease the working efficiency(such as compensation about error or deviation) of the robot manipulator. So in this paper we present the controller gain tuning law by which we can find the controller gain which satisfies the per-formance specification of the robot manipulator during working of the robot. The proposed algorithm is derived from the Laypunov direct method. And by the simulation on the 4-axis SCARA type robot(SAMSUNG SM5 Robot) we guarantee the performance of this algorithm.

• Proceedings of the KIEE Conference
• /
• 2000.07d
• /
• pp.2729-2731
• /
• 2000

In this paper, we propose an adaptive controller using RBFN(radial basis function network) for robot manipulators. The structure of the proposed controller consists of a RBFN and a fixed gain PD controller. On the basis of the Lyapunov stability theorem, we guarantee the UUB (uniformly ultimately boundedness) for the total system. And the learning law of RBFN is established by the Lyapunov method. Finally, we apply the proposed controller to tracking control for the 2 link SCARA type robot manipulator.

• Journal of Electrical Engineering and Technology
• /
• v.3 no.2
• /
• pp.263-270
• /
• 2008

We studied partial discharge detection by sensing electromagnetic waves emitted from the partial discharge source in an HV Rotating Machine using a UWB sensor. In this study, we design a new type of compact low frequency UWB sensor based on micro-strip technology. We also perform many experiments of offline and dismantled testing compared with the existing HFCT on stator winding of the HV generator. We mention the detailed design of a new compact UWB sensor along with the time domain PRPD pattern and frequency domain results of partial discharge in the stator winding of a 6.6kV rotating machine by offline testing performed in a laboratory.