• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 제39회 하계학술대회
• /
• pp.1067-1068
• /
• 2008

The Operation of high speed train in year 2004 bring about a great change in railroad industry. Especially in railroad construction field we have acquired great Know-how. And up to now we are building up operation skills. But the high speed train system are totally imported, so it is necessary to investigate some of the equipment based on our own environment. In case of Toughened Glass Stem Insulator, we don't have any application case in domestic and limited in abroad. So there must be some characteristic estimation. The estimation was made in three different ways. First electrical field cause, Second physical field cause and finally in circumstance cause. In Electrical field cause, amplitude and number of time for abnormal peak voltage data are collected. And in physical field cause, amplitude and trend of vibration in to the insulator are examined. And I circumstance cause, possibility of flying gravel and ice clod are investigated. Through this basic data suitability for Toughened Glass Stem Insulator using in domestic will be accumulated.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.286-288
• /
• 2007

In this paper, the fast locking PLL Frequency Synthesizer with low phase noise in a 0.18um CMOS process is presented. Its main application IS for the 915MHz ISM band wireless transponder upon the CPFSK (Continuous Phase Frequency Shift Keying) modulation scheme. Frequency synthesizer, which in this paper, is designed based on self-biased techniques and is independent with processing technology when damping factor and bandwidth fixed to most important parameters as operating frequency ratio, broad frequency range, and input phase offset cancellation. The proposed frequecy synthesizer, which is fully-integrated and is in 320M $^{\sim}$ 960MHz of the frequency range with 10MHz of frequency resolution. And its is implemented based on integer-N architecture. Its power consumption is 50mW at 1.8V of supply voltage and core area is $540{\mu}m$ ${\times}$ $450{\mu}m$. The measured phase noises are -117.92dBc/Hz at 10MHz offset, with low settling time less than $3.3{\mu}s$.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
• /
• pp.478.2-478.2
• /
• 2014

Atomic layer deposition (ALD) provides self-limiting processes based on chemisorption-based reactions. Such unique features allow for superior step coverage, atomic-scale control in thickness, and surface-dependent reaction controls. Furthermore, the surface-limited deposition enables the artificial deposition of oxide and/or metallic materials onto the porous systems as long as the supply is guaranteed in terms of time in providing reactant species and removing the byproducts and redundant reactants. The unique feature of atomic layer deposition is applied to solid oxide fuel cells whose incorporates two porous cathode and anode compartments in addition to the ionic electrolyte. Specific materials are deposited to the surface sites of porous electrodes, with the aim to controlling the triple phase boundaries crucial for the optimized SOFC performances. The effect of ALD on the SOFC performance is characterized using current-voltage characteristics in addition to frequency-dependent impedance spectroscopy. The pros and cons of ALD-controlled SOFCs are discussed toward high-performance SOFC systems.

• 대한전기학회논문지:전력기술부문A
• /
• 제49권6호
• /
• pp.305-311
• /
• 2000

This paper presents a hybrid algorithm for solving optimal power flow(OPF) in order to enhance a systems capability to cope with outages, which is based on combined application of evolutionary computation and local search method. The efficient algorithm combining main advantages of two methods is as follows : Firstly, evolutionary computation is used to perform global exploitation among a population. This gives a good initial point of conventional method. Then, local methods are used to perform local exploitation. The hybrid approach often outperforms either method operating alone and reduces the total computation time. The objective function of the security constrained OPF is the minimization of generation fuel costs and real power losses. The resulting optimal operating point has to be feasible after outages such as any single line outage(respect of voltage magnitude, reactive power generation and power flow limits). In OPF considering security, the outages are selected by contingency ranking method(contingency screening model). The OPF considering security, the outages are selected by contingency ranking method(contingency screening model). The method proposed is applied to IEEE 30 buses system to show its effectiveness.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2008년도 춘계학술대회 논문집
• /
• pp.423-427
• /
• 2008

The Operation of high speed train in year 2004 bring about a great change in railroad industry. Especially in railroad construction field we have acquired great Know-how. And up to now we are building up operation skills. But the high speed train system are totally imported, so it is necessary to investigate some of the equipment based on our own environment. In case of Toughened Glass Stem Insulator, we don't have any application case in domestic and limited in abroad. So there must be some characteristic estimation. The estimation was made in three different ways. First electrical field cause, Second physical field cause and finally in circumstance cause. In Electrical field cause, amplitude and number of time for abnormal peak voltage data are collected. And in physical field cause, amplitude and trend of vibration in to the insulator are examined. And I circumstance cause, possibility of flying gravel and ice clod are investigated. Through this basic data suitability for Toughened Glass Stem Insulator using in domestic will be accumulated.

• 조명전기설비학회논문지
• /
• 제25권11호
• /
• pp.73-82
• /
• 2011

The solid insulation system of stator windings in high voltage rotational machines is usually aging in accordance with long time operation. The partial discharge test have been known to check whether insulation deterioration exist or not, and the PD test can effectively diagnose a solid insulation condition regardless of during operation(on-line) or not(off-line). The on-line PD measurement have proven to be a successful technique in monitoring stator insulation condition nowadays. This paper describes the characteristics of comparing the on-line PD measurement data using PDMS-HG(Partial Discharge Monitoring System for Hydro-electric Generator) installed in field with the off-line diagnosis measurement data(insulation resistance, winding resistance, PI, ${\Delta}tan{\delta}$ and PD) on hydro generator(13[kV]) stator windings. These results make good use of managing rotational machines through evaluating the solid insulation condition of stator windings.

• Journal of Communications and Networks
• /
• 제17권6호
• /
• pp.656-664
• /
• 2015

This study analyzes the performance of power-line communications for sending open automated demand response (OpenADR) signals. In particular, we study main channel disturbances that can affect end-to-end communications and which have not been previously studied in detail. Our analysis takes into account physical phenomena, such as background and impulsive noise sources, channel attenuation, and multipath effects, and considers the physical, network, and applications layers of the communications structure. The performance of the physical layer is the basis for computing the packet error rate. In analyzing application performance, we focus specifically on the latency in several communication environments. If a channel is impaired only by background noise, latencies are less than 40 seconds. With the addition of impulsive noise in the channel, this value increases as long as 68 seconds. Using these figures, we find that power-line technology is more suitable for "slow" demand programs, such as day-ahead or day-of curtailments, rather than ancillary services markets, which require near-real-time communication.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
• /
• pp.32-33
• /
• 2006

As next generation nonvolatile memory, chalcogenide-based phase change memory can substitute for a conventional flash memory from its high performance. Also, fast writing speed, low writing voltage, high sensing margin, low power consumption and repetition reliability over $10^{15}$ cycle shows its possibility. At our laboratory, we invented ${Ge_1}{Se_1}{Te_2}$ material to alternate with conventional ${Ge_2}{Sb_2}{Te_5}$ for improve its ability. We respect the ${Ge_1}{Se_1}{Te_2}$ material can be a solution for high power consumption problem and long time at 'set' performance. A conductivity experiment from variable temperature was performed to see reliability of repetition at read and write performance. Compare with conventional ${Ge_2}{Sb_2}{Te_5}$ material, these two materials are used as complex compound to get the finest parameter.

• 한국전기전자재료학회논문지
• /
• 제28권4호
• /
• pp.249-251
• /
• 2015

In this study, the application of biosensor having a large surface area for more effective and AAO (anomic aluminium oxide) template in order to gain concentration and voltage of anodizing process morphology changes to the control of experiments were conducted. The biosensor surface may increase the response characteristics by having a large surface area. So the entrance to a little more efficient wide depth sensing experiment was carried out to obtain a structure body with a branch shape with a large surface area with increasing. Experimental results from the FE-SEM observation was obtained template morphology. As a result, depending on the anodizing time, the depth of the layer of aluminum oxide was found that it was confirmed that the deepening of the pore size changes according to anodizing condition. And measuring the detection performance according to the conditions in the electrolyte and the reaction because of blood using a biosensor measuring sensing property according to the depth of the pore depth is considered that does not have a significant impact.

• Journal of Power Electronics
• /
• 제12권5호
• /
• pp.813-820
• /
• 2012

This paper presents the development of a software supported acquisition system for metrological verification and testing of the equipment for monitoring and analysis of the basic electrical power quality parameters. The described procedure consists of two functionally connected segments. The first segment involves generation of the reference three-phase voltage signals, including the possibility of simulation of the various power quality disturbances, typical for electrical power distribution networks. The second part of this procedure includes the real-time recording of power quality disturbances in three-phase distribution networks. The procedure is functionally supported by the virtual instrumentation concept, including a software application developed in LabVIEW environment and data acquisition boards NI 6713 and NI 9215A. The software support of this system performs graphical presentation of the previously generated and recorded signal waveforms. A number of the control functions and buttons, implemented on the virtual instrument front panels, are provided to adjust the basic signal acquisition, generation and recording parameters.