• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.562-564
• /
• 2008

This paper deals with the three phase high voltage power-grid connection topology using multi-level inverter. Due to the multi-level inverter, these are improved effect of fluctuating voltage, problem of EMC and switching loss using suitable switching patterns of device, above all thing, it is easy to realize the system because of using lower voltage rating switch. This topology can be applicable to power-grid connection of wind system, there is a good point about economical efficiency. The simulation results are presented to verify the validity of the proposed topology.

• IMMUNE NETWORK
• /
• v.12 no.6
• /
• pp.230-239
• /
• 2012

Activation-induced cytidine deaminase (AID) is an enzyme that is predominantly expressed in germinal center B cells and plays a pivotal role in immunoglobulin class switch recombination and somatic hypermutation for antibody (Ab) maturation. These two genetic processes endow Abs with protective functions against a multitude of antigens (pathogens) during humoral immune responses. In B cells, AID expression is regulated at the level of either transcriptional activation on AID gene loci or post-transcriptional suppression of AID mRNA. Furthermore, AID stabilization and targeting are determined by post-translational modifications and interactions with other cellular/nuclear factors. On the other hand, aberrant expression of AID causes B cell leukemias and lymphomas, including Burkitt's lymphoma caused by c-myc/IgH translocation. AID is also ectopically expressed in T cells and non-immune cells, and triggers point mutations in relevant DNA loci, resulting in tumorigenesis. Here, I review the recent literatures on the function of AID, regulation of AID expression, stability and targeting in B cells, and AID-related tumor formation.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.39 no.6
• /
• pp.557-567
• /
• 1990

This paper describes the static and dynamic characteristic analysis of the Series Resonant DC to DC Converter with frequency control. The natural commutation of all switch element is realized when the switching frequency is below the resonant frequency of the tank circuit, and the analysis is limited to only this region. For the analysis method, state plane technique is adopted, and each operation mode is defined from normalized switching frequency Fsn. Under this condition, circuit performance is analyzed ideally. The physical characteristics of the series resonant converter is easily grasped by this analysis method with frequency control and this analytical results are directly applicable to the actual converter design. The validity of the analysis is verified by comparing with experimental results and the stability of the converter is confirmed against small variations around the operating point by conventional frequency domain analysis.

• Proceedings of the IEEK Conference
• /
• 1999.06a
• /
• pp.154-157
• /
• 1999

Photonic Slot Routing(PSR) is a promising approach to solve the fundamental scalability problem of all-optical packet switched WDM networks. In photonic slot routing, packets destined for the same subnetwork are aggregated to form a photonic slot which is jointly routed as a single unit of information through the network. The relative location of the nodes from bridge may cause to fairness problem in the unidirectional WDM ring network based on PSR. As photonic slots from different subnetworks can originate contentions at the bridge, packets may be dropped and retransmitted. Thus we evaluated the performance of PSR based WDM ring network in the point of fairness for each node and slot contentions at the bridge. Simulation results show that the PSR based WDM ring requires a slot access mechanism to guarantee the transmission fairness and efficient switch architecture to resolve slot contention at the bridge.

• Proceedings of the KSPS conference
• /
• 1996.10a
• /
• pp.117-122
• /
• 1996

This paper proposes a derivational account of tensing and neutralization of obstruents in Korean within the theory of Government Phonology (GP) (Kaye, Lowenstamm and Vergnaud 1990, henceforth KLV; Park 1996). We begin by outling the relevant tensing and neutralization data in Korean. We point out several problems that need to be addressed in any account of these data. We then set out the central notions of GP, pointing out how adherence to the requirement that government relations remain constant throughout a derivation under the Projection Principle prevents a GP account of tensing and neutralization in Korean, which requires government relations to switch between lexical and phonetic representations. To address this problem, we propose abandoning the Projection Principle, extending lexical representations in GP along the lines of the Markedness Theory approach (Michaels 1989), and adopting the economy principles for derivation of the Minimalist approach (Chomsky 1993; Chomsky & Lasnik 1991). finally, we summarize the analysis of obstruent phenomena in Korean within GP extended in these ways.

• Proceedings of the KIPE Conference
• /
• 1998.07a
• /
• pp.260-264
• /
• 1998

Three phase Boost/Buck converter which have economical merits and simple control scheme, are analyzed and evaluated through comparative methods and digital simulation for equivalent load. Those play a part of voltage boost/buck as well as power factor correction with single switch. Controller operating in constant and variable frequency is used for rapid output response and stable system condition respectively. Moreover low THD property of single switched converters is available for inverter arc welding machine known as high power and low power factor. So, in this paper a comparison of the characteristics in boost and buck converter is described and then simulation results conforms the merits from point of view of power factor and voltage regulator.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.39 no.9
• /
• pp.934-943
• /
• 1990

There are no turn-on losses in the series Resonant Converter which operates above the resonance frequency, and the commutation stress on the switched component is low. For a given Series Resonant Converter with specified load resistance, the output voltage is a function of the operation frequency. This paper describes the static and dynamic characteristic analysis of the Series Resonant DC to DC Converter, which is operating above the resonant frequency, with frequency control. For the analysis method, state plane technique is adopted, and the circuit operation is defined from normalized switching frequency, Fsn. Under this condition, circuit performance is analyzed ideally. The validity of the proposed analysis is verified by comparing with experimental results, the stability of the converter is confirmed against small variations around the operating point by conventional frequency domain analysis, and the stress quantity added to switch component is shown.

• Journal of KIISE:Computing Practices and Letters
• /
• v.5 no.3
• /
• pp.336-343
• /
• 1999

본 논문은 지능형 정보 제공 시스템(IP : Intelligent Peripheral)의 주요 소프트웨어 블록 중 하나인 자원 서비스 제어부의 구현 방법을 설명한 것이다. 본 연구의 자원 서비스 제어부는 ITU-T INCS-1에 정의된 특수자원 기능실체(SRF : Specialized Resource Function)의 상태모델을 실현시킨 소프트웨어 블록으로서 IP 하드웨어 구성요소의 하나인 특수자원교환기(SRS : Specialized Resource Switch) 의 CROS(Concurrent Realtime perating System)상에서 CHILL(CCITT High Level Programming Language)로 구현되었으며, 지능망서비스제어시스템(SCP : Service Control Point)이 보낸 지능망 응용프로토콜(INAP : Intelligent Network Application Protocol)오퍼레이션을 분석하여 IP가 보유한 자원 구동에 필요한 모든 절차를 제어한다. 또한 동시에 수신된 INAP오퍼레이션들에 대한 순서제어기능, 통계데이타 제공기능, 사용자 상호작용 종료 기능등을 제공한다. 제안된 구현기술은 자원서비스 제어부가 실제 자원을 동작시키는 IP 하드웨어 구성요소인 특수자원유닛(SRU : Specialized Resource Unit)을 클라이언트/서버형태로 유지하여 이들 자원의 상태를 관리함으로써 IP의 확장성을 보잔하여, 교환기 실시간 데이터베이스를 이용하여 IP가 생성하는 수만여개의 메시지를 효율적으로 관리할 수있다.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.2 no.6
• /
• pp.110-116
• /
• 1994

In this research, the tensile strength of molded parts and pressure distribution were analyzed to study the cavity filling stage and packing stage in injection molding. The measurement of cavity pressure was obtained by a data acquisition system with the installation of transducers in the cavity. Molded parts were tested by a universal testing machine to obtain the tensile strength. For the experimental work, the tensile strength of molded parts increased with longer packing time and exact freezing time of the gate was obtained by a cavity pressure curve. In addition, the effect of packing did not occur and tensile strength was almost constant after early 1.5 sec of the freezing time of gate. Density tended to be higher about 0.2% due to a larger degree of mold temperature and melt temperature. Also, changing pressure in the cavity was effectively sensed. Thereafter, the possibility of the development of pattern recognition expert system was confirmed on the basis of the experimental results.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.8
• /
• pp.1360-1366
• /
• 2007

In this paper, the load balancing which is one of the distribution power system's operation purposes was studied. Reconfiguration of Distribution power system presents that the configuration is changed by changing the switch on/off status which exists in the system according to the mentioned purpose. Through this method, the load of distribution power system is shown to be balanced. As a characteristic of complicated distribution power system, system is designed by being applied by OOP(Object Oriented Programming) method which connected more flexibly than existing Procedural Programming method, and the process of calculating the distflow and the loss of configurated system is shown. In addition, this paper suggests more efficient method compared by the results of reconfiguration on the purpose of the loss minimization and by the result of distribution power system reconfiguration on the purpose of load balancing. Moreover, it searches for the method to approach the global optimal solution more quickly.