• Journal of the Korea Society of Computer and Information
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• v.15 no.5
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• pp.93-101
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• 2010

Although various network management architectures such as centralized, distributed, and hybrid have been presented, any one is not always efficient in all the environment. In this paper, we propose a hierarchical and split network management architecture based on MA+SNMP in order to manage a network of many small NEs distributed over the wide area. Our hierarchical architecture has MA-based proxy management nodes for the flexibility and overhead reduction in NMS as well as SNMP-based NEs considering NE's capacity. Through the analysis with real experiments, we show that our proposal improves some drawbacks and the processing delay of the existing architectures in the given environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.2B
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• pp.133-142
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• 2007

WPANs are formed in relatively small area and a PNC that serves as a central control device plays an important role in the operation and organization of a piconet. Typical applications of WPANs are security system and health monitoring system. In these type of systems, guaranteeing realtime service is very important, and communications cannot take place when the PNC malfunctions. Thus, in this situation, it is necessary to elect a new PNC as soon as possible. For this reason, we propose distributed PNC election scheme that considers not only QoS support but also network connectivity to avoid possible network partition. Simulation results show proposed mechanism can select PNC with guaranteeing QoS and connectivity for a limited period.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.1
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• pp.1-7
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• 1998

The near field radiated from the monopole antenna of the cellular phone was calculated by using the modified finite difference time domain algorithm derived from the integral form of Maxwell's equations. Substituting the near field value into the differential form of Maxwell's equations, SAR's distribution in the human head was obtained. The human head was simulated by a model of 800,000 block cells with dielectric constant and conductivity. The cell size was taken to be 0.5 cm. the transmitted power of the cellular phone was assumed to be 0.6 watts at the frequency of 833 MHz. The distance between the head and the cellular phone was 2.0 cm, the maximum SAR induced in the human head was about 1.5 W/kg and was below the IEEE's upper safety limit of 1.6 W/kg.

• The KIPS Transactions:PartC
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• v.13C no.7 s.110
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• pp.897-904
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• 2006

In large-scale MANETs, the performance of MANET routing protocols is degraded significantly. To avoid this, zone-based hierarchical architecture is proposed. In this architecture, single large-scale MANET is divided into multiple small-scale MANETs. In this paper, we propose autoconfiguration-coupled MANET routing protocol to reduce routing overhead of mim user nodes. If MANET routing protocol utilizes the autoconfigured information of each user node, its overhead or procedure can be reduced. Proposed method shows the degradation of routing overhead of user nodes via simulation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.181-182
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• 2009

In the machinery, the brake system is as important part as machine's working. If the machine doesn't stopped, would be big occident. For the ships, it is important too. Use the windlass winch to stop the voyage and use mooring winch to keep the stop in the port. In this study, improve the braking power divided the brake band and search the optimize portion.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.6
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• pp.547-553
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• 1999

A new multi-step voltage source inverter is proposed in this paper. The proposed scheme is composed of t the double-connected 12-step inverter with an auxiliary circuit. The auxiliary circuit includes two voltage d dividing capacitors, two switching devices and a low KV A autotransformer. The resultant system is shown to b be a 24-step inverter suitable for medium power level SVC applications in which the PWM method can not be e employed. A 36-step operation can also be 이)tained by the addition of a bidirectional switch to the ProlXlsed I inverter. The design parameters are derived from the analysis of voltages and currents by means of switching f functions. The validity of the proposed scheme is confirmed by the simulated and experimental results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.5
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• pp.939-948
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• 1997

In this paper, we propose the new rate-based transmission rates control algorithm that allocates the fair band-width for ABR service in ATM network. In the traditional ABR service, bandwidth is allocated with constant rate increment or decrement, but in the proposed algorithm, it is allocated fairly to the connected calls by the fuzzy inference of the available bandwidth. The fuzzy inference uses buffer state and the buffer variant rate as the input variables, and uses the total transmission rate as a output variable. This inference a bandwidth is fairly distributed over all ABR calls in service. By simmulation, we showed that the proposed method improved 0.17% in link effectiveness when RIF, RDF is 1/4, 38.6% when RIF, RDF 1/16, and 82.4% when RIF, RDF 1/32 than that of the traditional EFPCA.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.4
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• pp.63-69
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• 2012

This paper describes novel scheme of a gray scale capacitive fingerprint image for high-accuracy capacitive sensor chip. The typical gray scale image scheme used a DAC of big size layout or charge-pump circuit of non-volatile memory with high power consumption and complexity by a global clock signal. A modified capacitive detection circuit of charge sharing scheme is proposed, which uses DLC(down literal circuit) based on a neuron MOS(vMOS) and analog simple multiplexor. The detection circuit is designed and simulated in 3.3V, $0.35{\mu}m$ standard CMOS process. Because the proposed circuit does not need a comparator and peripheral circuits, a pixel layout size can be reduced and the image resolution can be improved.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.06a
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• pp.76-79
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• 2019

본 논문에서는 얼굴 검출에서 좋은 성능을 보이는 Dual Shot Face Detector (DSFD)을 WIDER FACE 데이터 기반으로 네트워크의 성능 및 특성을 분석한다. 얼굴 검출 엔진의 동작 및 학습을 확인하기 위해 WIDER FACE 데이터를 기반으로 DSFD 를 학습한 후 기존 논문에서 발표되었던 성능을 보이는지 확인한다. 성능 확인된 얼굴 검출기 DSFD 를 세부적으로 분석하기 위하여 테스트 데이터를 10 개 그룹으로 분할하여 AP 측정 후 성능 열화가 높은 그룹의 이미지를 집중적으로 분석하였다. 분석 결과 얼굴 영역 주변에 모자 헬멧, 방패 등에 의해 가려진 경우 얼굴 검출에 많은 어려움이 발생했다. 또한 이미지에 있는 상황을 61 개로 구분하여 정량적 분석을 수행하며 분석 결과 Car Accident 와 People Marching 상황에서 성능이 열화되는 것을 확인하였다. 본 논문에서는 DSFD 네트워크의 성능 열화 부분 및 경향 등을 분석하였다. 이러한 내용은 DSFD 얼굴 검출기의 성능을 개선하거나 특정 도메인에 맞는 검출기를 개발하는데 매우 중요한 자료가 될 것으로 생각한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.6
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• pp.69-74
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• 2023

In this paper we review techniques for building and analyzing wavelets on irregular point sets in one and two dimensions. In particular we focus on subdivision schemes and commutation. Subdivision means the skill that approximates the initial lines or mesh into a tender curve or a curved surface by continuous partitioning operation. The key to generalizing wavelet constructions to non-traditional settings is the use of generalized subdivision. The first generation setting is already connected with subdivision schemes, but they become even more important in the construction of second generation wavelets. Subdivision schemes provide fast algorithms, create a natural multi-resolution structure, and yield the underlying scaling functions and wavelets we seek.