• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권3호
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• pp.99-104
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• 2002

lateral insulated gate bipolar transistors(LIGBTs) are extensively used in high voltage power IC application due to their low forward voltage drops. One of the main disadvantages of the LIGBT is its scow switching speed when compared to the LDMOSFET. And the LIGBT with reverse channel structure is lower current capability than the conventional LIGBT at the forward conduction mode. In this paper, the LIGBT which included p+ ring and p-channel gate is presented at the reverie channel structure. The presented LIGBT structure is proposed to suppress the latch up, efficiently and to improve the turn off time. It is shown to improve the current capability too. It is verified 2-D simulator, MEDICI. It is shown that the latch up current of new LIGBT is 10 times than that of the conventional LIGBT Additionally, it is shown that the turn off characteristics of the proposed LIGBT is i times than that of the conventional LIGBT. It is net presented the tail current of turn off characteristics at the proposed structure. And the presented LIGBT is not n+ buffer layer because it includes p channel gate and p+ ring.

• 한국광학회지
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• 제5권2호
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• pp.333-339
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• 1994

단일모드 광섬유를 부착한 고속 광통신용 PIN-전치증폭기 모듈을 GaInAs PIN 광검출기와 GaAs 전치증폭기를 하이브리드로 집적하여 제작하였다. PIN 광검출기의 정전용량은 0.35pF이었으며 이 소자의 수광직경은 $20{\mu}m$였다. 제작된 수광모듈의 -3dB 차단주파수는 2GHz 이상이었으며 2.5Gbps NRZ$(PRBS=2^{23}-1)$ 입력광신호에 대해 비트오율이 $10^{-9}$일 때 -25.2dBm의 수신감도를 보였다.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2001년도 3rd Korea-Japan Advanced Semiconductor Packaging Technology Seminar
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• pp.121-145
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• 2001

Chip Size Packages (CSP) are now widely used in high speed DRAM. The major driving farce of CSP development is its superior electrical performance than that of conventional package. However, the power dissipation of high speed DRAM like DDR or RAMBUS DRAM chip reaches up to near 2W. This fact makes the thermal management methods in DRAM package be more carefully considered. In this study, the thermal performances of 3 type CSPs named $\mu-BGA$^{TM}$$ $UltraCSP^{TM}$ and OmegaCSP$^{TM}$ were measured under the JEDEC specifications and their thermal characteristics were of a simulation model utilizing CFD and FEM code. The results show that there is a good agreement between the simulation and measurement within Max. 10% of $\circledM_{ja}$. And they show the wafer level CSPs have a superior thermal performance than that of $\mu-BGA.$ Especially the analysis results show that the thermal performance of wafer level CSPs are excellent fur modulo level in real operational mode without any heat sink.

• 한국표면공학회지
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• 제38권6호
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• pp.234-240
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• 2005

In this study, ion nitriding of a EHA pump part made of AISI 4340 steel was performed under different applied power conditions to study the relationship between dimensional changes of specimens and the type of applied power source. Microstructures and micohardness distribution at different processing conditions were also examined. Duplex surface treatment of ion nitriding with the optimum process conditions to produce the minimum dimensional variation in a EHA pump part and a TiN thin film coating by unbalanced magnetron sputtering was performed and the specimens with a duplex surface treatment were subjected to a high speed wear test to evaluate the wear performance of EHA hydraulic pump parts with various surface treatment conditions. Results indicated that uniform and continuous surface layer with a minimum dimensional variation could be obtained by ion nitriding with bipolar mode power source and much enhanced wear characteristics with a duplex surface treatment could be obtained, compared with results from ion nitriding or single-layerd TiN coating specimens.

• 한국산학기술학회논문지
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• 제15권8호
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• pp.4796-4801
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• 2014

관절형 고속철도차량의 승차감 향상 및 주행안전을 위해서는 객차 갱웨이 통로연결막에 대한 화재안전성, 방음기능과 함께 3축 회전각변위(롤링/요잉/피칭) 모드하의 내구성을 만족하는 것이 중요하다. 그러나 국내의 경우 본 통로연결막에 대한 내구성 시험 및 규격은 아직 표준화되지 않고 있다. 본 연구에서는 비선형 구조해석 결과와 고무피로특성으로부터 피로 수명을 예측하였다. 또한, 리그 피로시험을 구축하여 본 부품의 내구성을 검토하였다.

• 전자공학회논문지S
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• 제35S권10호
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• pp.34-41
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• 1998

본 논문에서는 155Mbps 급 ATM 고속위성 전송에 적합한 동기 요소기술을 제시하고 추적성능 개선을 위한 최적 알고리즘을 제안하였다. 이때 신호변조는 QPSK방식을 사용하였고 수신기는 버스트 모드로 동작함을 가정하였다. 이러한 점을 바탕으로 주파수동기(AFC), 위상동기(CR), 비트동기(STR)의 여러 요소기술 및 방식을 검토하고 문제점을 개선한 방안을 제시하였다. 또한 AWGN 채널 환경하에서 요구 심벌수, 정상상태 안정도, 그리고 하드웨어(H/W) 구현 난이도에 중점을 두어 제안한 각 동기 요소기술의 제반 성능평가를 수행하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제33권6호
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• pp.918-924
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• 2009

This paper deals with the experimental assessment of the vibration suppression of the smart structures. First, we have presented the paper about the new high-speed active control system that we have developed using the DSP320C6713 microprocessor and a peripheral system composed of a data acquisition system, A/D and D/A converters, piezoelectric (PZT) actuator/sensors, and drivers using PA95. Since fast data processing is very important in the active vibration control of the structures, we utilized the fast processing DSP320C6713 microprocessor as a main processor to the controller and fast peripheral devices for fast control loop. To realize a fast active vibration control, we have analyzed and tested the processing time of the peripheral devices and provided the corresponding test results. Especially, we have focused on achieving the fast signal amplification of the PA95 device since it takes most of loop times of the control system. Finally, we performed numerous experiments of active vibration control of the aluminum plate to validate the superior performance of the developed control system based on previous mode tests of the plate.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.3013-3018
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• 2008

Supercharging system was adopted to investigate the influence of boost pressure on operating range, brake specific fuel consumption (BSFC) and exhaust emissions by using a supercharger at low temperature diesel combustion (LTC) condition in a 5-cylinder 2.7 L direct injection diesel engine. The experimental parameters such as injection quantity, injection timing, injection pressure and exhaust gas recirculation (EGR) rate were varied to find maximum operating range. The result showed that operating range with boost was expanded up to 41.9% compared to naturally aspirated LTC condition due to increased mixing intensity. The boosted LTC engine showed low BSFC value and dramatically reduced soot emission under all operating range compared with high speed direct injection (HSDI) mode. Finally, this paper presents the boosted LTC map of emission and the strategy of improved engine operating range.

• 한국통신학회논문지
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• 제25권9B호
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• pp.1518-1526
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• 2000

본 논문은 기존 표준 단일모드 광섬유 링크를 통하여 초고속 광신호의 장거리 전송이 가능하도록 분산보상 광섬유를 이용한 최적 분산보상 기법에 기반을 둔 전송링크 설계 방법을 제안하였다. 제안한 방법에서는 광섬유의 비선형성에서 비롯되는 자기위상변조(Self-Phase Modulation: SPM)와 광증폭기에서 발생하는 증폭자연방출(Amplified Spontaneous Emission : ASE) 잡음에 대하여 증폭기간 거리와 중계기간 거리를 최적화함으로써 전송신호 속도에 따른 최대 전송거리를 제시하였다. 또한 주어진 증폭기간 거리와 중계기간 거리에 대하여 ASE 잡음과 SPM의 효과의 균형적 관계로부터 최적의 입력 신호전력의 범위가 있음을 제시하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권10호
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• pp.4015-4033
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• 2015

The future mobile networks consist of hyper-dense heterogeneous and small cell networks of same or different radio access technologies (RAT). Integrating mobile networks of different RATs to provide seamless and smooth mobility service will be the target of future mobile converged network. Generally, handover from high-speed networks to low-speed networks faces many challenges from application perspective, such as abrupt bandwidth variation, packet loss, round trip time variation, connection disruption, and transmission blackout. Existing inter-RAT handover solutions cannot solve all the problems at the same time. Based on the high-layer convergence sublayer design, a new receiver-aided soft inter-RAT handover is proposed. This soft handover scheme takes advantage of multihoming ability of multi-mode mobile station (MS) to smooth handover procedure. In addition, handover procedure is seamless and applicable to frequent handover scenarios. The simulation results conducted in UMTS-WiMAX converged network scenario show that: in case of TCP traffics for handover from WiMAX to UMTS, not only handover latency and packet loss are eliminated completely, but also abrupt bandwidth/wireless RTT variation is smoothed. These delightful features make this soft handover scheme be a reasonable candidate of mobility management for future mobile converged networks.