• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2014년도 추계학술대회
• /
• pp.773-776
• /
• 2014

본 연구에서는 채널 길이와 폭의 변화에 따른 실리콘 나노와이어 MOSFET 소자의 아날로그 특성을 비교 분석 하였다. 측정 온도는 $30^{\circ}C$, $50^{\circ}C$, $75^{\circ}C$, $100^{\circ}C$이다. 사용된 소자의 폭은 20nm, 30nm, 80nm, 130nm 와 길이는 250nm, 300nm, 250nm, 500nm을 사용하였다. 소자의 아날로그 특성은 이동도, 트랜스컨덕턴스, Early 전압, 전압이득, 드레인 전류 이다. 이동도는 폭이 증가함에 따라 증가하고 길이와 온도가 증가할수록 감소한다. 트랜스 컨덕턴스는 폭이 증가하면 증가한다. Early 전압은 길이와 온도가 증가함에 따라 증가하고 폭이 증가함에 따라 감소한다. 따라서 이득은 폭의 감소와 길이가 증가함에 따라 증가하고 온도가 증가함에 따라 감소하는 것을 알 수 있었다.

• 한국전기전자재료학회논문지
• /
• 제19권2호
• /
• pp.169-175
• /
• 2006

This study investigated variation leakage current maximum value and waveform considering applied voltage phase angel by simulating three environmental conditions, such as fog, salt fog, and kaolin contamination .As the result of applied voltage phase angel characteristics, leakage currents presented almost in phases in the early stage regardless of environmental conditions just after applying the voltage, and the phase of leakage currents certain phase lags for the discharge of the applied voltage when surface discharges occurred due to the continuous environmental contamination. In addition, the difference in phase significantly increased according to the intensity of discharges. The change in distortion rates according to the environmental contamination presented a nearly same level just after applying the voltage. The distortion rate of third harmonic for the fundamental wave presented by the order of fog>salt fog>kaolin when surface discharges occurred due to the applied voltage for certain continued periods. In the case of the fog and salt fog, the scale of spectrums decreased according to the increase in frequencies from the results of the analysis of high frequencies. In addition, the even number frequency presented a relatively large level compared to the odd number frequency under the kaolin contamination.

• 한국전기전자재료학회논문지
• /
• 제29권7호
• /
• pp.449-453
• /
• 2016

The amount of electrical energy has been increased with the rapid development of the industrial society. Accordingly, operating voltage of the power equipment and facility capacity are continuously increasing. Development trends of recent high-voltage electrical equipment are ultra high-voltage, large-capacity and compact. Early diagnosis of a failure of the power plant has been emerging as an important task as to supply high quality power to users. In this study, we have tried to develope an algorithm for distinguishing an arc fault signal generated in the power plant by using UV sensor.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1994년도 추계학술대회 논문집
• /
• pp.134-138
• /
• 1994

According to request of insulating materials for high-voltage, recently we make effort not only to develop diagnostic skills of aging state but also to discover defects in insulating material in the early. Especially, partial discharge has been actively studied as a non-destructive diagnosis technique and very useful method. Because the method of partial discharge measurement has damages less than other conventional diagnosis technique. In this paper, the characteristics of partial discharge was investigated and studied on many samples with voids. In order to adapt as a practical diagnosis technique, it is studied on the characteristics of partial discharge and insulation breakdown in the high voltage. We suggest that partial discharge measurement can be used in order to diagnose defects in high-voltage insulation materials.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제16권6호
• /
• pp.832-841
• /
• 2016

The voltage-frequency island (VFI) design paradigm has strong potential for achieving high energy efficiency in communication centric manycore system-on-chip (SoC) design called network-on-chip (NoC). However, because of the diminished scaling of wire-dimension and supply voltage as well as threshold voltage in modern CMOS technology, the vulnerability to link failure in VFI NoC is becoming a crucial challenge. In this paper, we propose an energy-optimized topology generation technique for VFI NoC to cope with permanent link failures. Based on the energy consumption model, we exploit the on-chip communication traffic patterns and characteristics of link failures in the early design stage to accommodate diverse applications and architectures. Experimental results using a number of multimedia application benchmarks show the effectiveness of the proposed three-step custom topology generation method in terms of energy consumption and latency without any degradation in the fault coverage metric.

• Journal of Electrical Engineering and Technology
• /
• 제4권1호
• /
• pp.123-130
• /
• 2009

The partial discharge (PD) measurement is a very effective method to assess the winding insulation condition of high-voltage machines, since most of the insulation failure processes are directly or indirectly caused by PD. On-line PD measurements, which can detect insulation defects of winding in the early stages on rotating machines in operation, have been accepted as the most important technique. The epoxy mica capacitive coupler is currently and extensively used for on-line detection of PD pulses of high-voltage rotating machines. To evaluate the feasibility of developing a capacitive coupler that is easier to manufacture at a lower cost compared to epoxy mica couplers, a 100pF capacitive coupler made of ceramic material is designed, fabricated and tested for on-line PD measurements of 23 kV electrical machines. A series of electrical tests and accelerated aging tests are performed on the ceramic coupler to evaluate the performance requirements, long-term reliability and thermal stability for in field application. The test results show that the newly developed ceramic coupler provides equal and improved performance at a lower cost compared to epoxy mica couplers, and estimated voltage life is anticipated to surpass 100 years.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 하계학술대회 논문집 A
• /
• pp.44-46
• /
• 2002

Service restoration following a complete or partial collapse starts with reenergize a transmission line from black-start generators. Voltage problems can arise by Ferranti effect as unloaded transmission line is reenergized. This paper presents analytical results on the primary restorative transmission system focused on the voltage problem during the early restoration process. Methodologies to handle load pick-up compensating Ferranti effect. and terminal voltage and reactive capability limitation of black-start generators about self-excitation are presented. An algorithm for static analysis about these methodologies is developed, and EMTDC simulation for verifying the efficiency of the algorithm is performed.

• Asian-Australasian Journal of Animal Sciences
• /
• 제14권12호
• /
• pp.1763-1768
• /
• 2001

The combined effects of low voltage electrical stimulation (ES) and early short-term temperature conditioning on meat quality of Hanwoo beef (Korean native cattle) during storage were investigated. Shear force was influenced by ES and aging. Combination of ES and the $30^{\circ}C$ conditioning resulted in higher myofibril fragmentation index and improved lightness. There was no substantial difference in drip loss among treatments but ES samples showed higher cooking loss than control. Negative effect on shelf-life was not found by early short-term high temperature conditioning. Therefore, the meat quality of Korean native cattle was effectively improved by the combination of ES and the $30^{\circ}C$ conditioning.

• 대한전자공학회논문지SD
• /
• 제42권1호
• /
• pp.25-32
• /
• 2005

본 논문에서는 단 채널 GaAs MESFET과 SOI-구조의 Si JFET가 갖는 전형적인 특성: i) 드레인 전압 인가에 의한 문턱전압 roll-off, ii) 포화영역에서의 유한한 ac 출력저항, iii) 채널길이에 대한 드레인 포화전류의 의존성 약화, 등을 통합적으로 기술할 수 있는 해석적 모델을 제안하였다. 채널 방향의 전계 변화를 포함하는 새로운 형태의 가정을 기존의 GCA와 대체하고, 채널의 전류 연속성과 전계-의존 이동도를 고려하여, 공핍영역과 전도 채널에서 2차원 전위분포 식을 도출해 내었다. 이 결과, 문턱전압, 드레인 전류의 표현 식들이 동작전압전 구간의 영역에 걸쳐 비교적 정확하게 도출되었다. 또한 본 모델은 기존의 채널 shortening 모델에 비해 Early 효과에 대한 보다 더 적절한 설명을 제공하고 있음을 보이고 있다.

• 한국진공학회지
• /
• 제14권1호
• /
• pp.29-34
• /
• 2005

실리콘-게르마늄 바이시모스(SiGe BiCMOS) 소자 제작시 발생하는 실리콘-게르마늄 이종접합 바이폴라 트랜지스터(SiGe HBT) 열화 현상에 대하여 고찰하였다. 독립적으로 제작된 소자에 비해 SiGe BiCMOS 공정에서의 SiGe HBT소자는 얼리 전압(Early voltage), 콜렉터-에미터 항복전압 및 전류이득등의 DC특성이 열화되고 상당한 크기의 베이스 누설전류가 존재한다는 것을 알 수 있었다. 또한 AC 특성인 차단주파수(f/sub T/) 및 최대 진동주파수(f/sub max/)도 1/2이하로 현저하게 저하되는 것을 확인하였다. 이는 고온의 소오스-드레인 열처리에 의한 붕소의 농도분포 변화가 에미터-베이스 및 콜렉터-베이스 접합 위치에 변화를 주고, 결국 실리콘-게르마늄 내에서의 접합 형성이 이루어지지 않아 전류 이득이 감소하고 기생 장벽이 형성되어서 발생한 현상이다.