• 한국농공학회:학술대회논문집
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• 한국농공학회 2002년도 학술발표회 발표논문집
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• pp.329-332
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• 2002

In the present study, in order to apply a cyclic viscoelastic-viscoplastic constitutive model to multi-layered ground conditions during large earthquake, the numerical simulations of the 1995 Hyogoken Nanbu Earthquake at Port Island, Kobe, Japan, were performed by the seismic respons analysis. From the seismic response analysis, it was verified that a cyclic viscoelastic-viscoplastic constitutive model can give a good description of the damping characteristics of clay accurately during large event which induces plastic deformation in large strain range.

• 전기의세계
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• 제24권4호
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• pp.80-82
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• 1975

This paper presents a synthesis procedure of multi-channel active filters, which realizes an arbitrary N*N matrix of real rational functions in the complex variable s as a voltage transfer matrix. The resultant network reveals a transformerless grounded active RC(2N+1)-terminal network. The active network is consisted of six 2N-port RC networks with 2N single-ended operational amplifiers.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 I
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• pp.386-389
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• 2003

This paper proposes the architecture of a multiple ring based optical network with single hop between edge nodes using either the concept of circuit switching or multi-wavelength label. The structure of the multi-wavelength label, be shown through the single wavelength-band and the multiple wavelength-band that can reduce number of ring. To avoid the collision of the optical packets at an outward port, we proposed the dynamic allocation scheme of the outward optical packets based on the fiber do]ay lines(FDLs).

• 한국항해학회지
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• 제24권1호
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• pp.65-72
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• 2000

This paper deals with the development of the generalized model to assist the empty container repositioning and leasing problems for liner shipping companies. For this, the existing models have been reviewed. And then a mathematical model has been proposed to handle the specific characteristics of the empty container management; the dynamic characteristics, the multi echelon of the transportation and distribution systems, and the substitutions among various container types. In particular, this paper puts an emphasis on the modeling framework for considering substitutions among various container types.

• 한국항만경제학회지
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• 제17권1호
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• pp.27-51
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• 2001

The purpose of this paper is to investigate the productive efficiency of world container ports by using the DEA (Data Envelopment Analysis) method and raw data from previous research in measuring the international competitiveness of world container ports. Ports have to cope with rapid changes in shipping environments. In order for a port to compete in the global market, it must provide port services promptly and accurately. Basically, there are two approaches to measuring the international competitiveness of a container port. First, there is the traditional productivity analysis method, which analyzes productivity based on the container port's facilities (efficiency, selectivity, land availability), and by its general capacity (handling ability, storage capacity, terminal productivity). Second there is multi-attribute utility analysis, which considers several elements including the reasons for selecting particular container ports and factors determining international competitiveness. This paper follows the first method (traditional productivity analysis) and extends the limitation of previous studies by using the DEA method newly, and suggesting: the relative productive efficiency of container ports. The main results of this paper are as follows: First, the results of the DEA analysis in terms of world container ports matches that of a previous study (Jun et al., 1993) at a level of 35%. The low ratio is due to the constrained set of input-output elements, the result of only twenty container ports being analyzed in this paper. Second, the result of the DEA analysis in terms of North-East Asia's container ports matches with that of a previous study (Ha, 1996) at a level of 100 percent. Therefore we can conclude that the DEA analysis is the best measurement method for international competitiveness. Policy implications for this study are as follows: First, when port authorities want to measure the international competition power of container ports and enhance their productive efficiency, they should consider the traditional method and newly introduce the DEA method. Second, according to the analysis results of the DEA method, pen authorities should recommend benchmarking ports as reference ports in order to enhance the productive efficiency of container ports that show an efficiency score of below 1.

• 한국전자파학회논문지
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• 제28권2호
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• pp.85-96
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• 2017

본 논문에서는 6-포트 회로망을 이용한 잡음파라미터 측정방법의 측정 주파수 대역을 확장하기 위한 2~18 GHz 광대역 6-포트 회로망을 설계 및 제작하였다. 광대역 6-포트 회로망을 설계하기 위해서 광대역 특성을 가지는 윌킨슨 전력분배기와 방향성 결합기를 설계하였다. 윌킨슨 전력분배기는 3단 구조로 설계하여 광대역 특성을 구현하였다. 방향성 결합기는 3단 구조 및 다층기판을 활용한 slot-coupled 구조로 설계하여 광대역 특성을 구현하였다. 설계된 광대역 전력분배기와 결합기를 이용하여 광대역 6-포트 회로망을 설계 및 제작하였다. 2~18 GHz 대역에서 제작된 6-포트 회로망의 측정결과는 잡음 파라미터 측정방법에 적용 가능한 특성을 보였다.

• 전자공학회논문지C
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• 제36C권8호
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• pp.22-34
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• 1999

본 논문에서는 내장된 이중-포트 메모리를 위한 효율적인 테스트 알고리듬을 제안하였다. 제안된 테스트 알고리듬은 기존의 멀티-포트 메모리 테스트 알고리듬들보다 훨씬 빠르게 이중-포트 메모리를 테스트할 수 있으며, 고착 고장, 천이 고장 및 결합 고장을 완벽하게 검출할 수 있다. 또한, 본 연구에서는 제안된 알고리듬을 수행할 수 있는 BIST 회로를 Verilog-HDL을 이용하여 설계하고 시뮬레이션과 합성을 수행하였으며, BIST로 구현된 제안된 테스트 알고리듬의 높은 효율성을 다양한 크기의 내장 메모리에 대한 실험을 통하여 확인할 수 있었다.

• 대한전자공학회논문지SD
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• 제42권2호
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• pp.57-64
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• 2005

본 논문에서는 내장된 메모리의 테스트를 편리하게 하기 위하여 간단한 사용자 설정에 의해 자동으로 BIST IP를 생성해 내는 범용 CAD 툴을 개발하였다. 기존의 툴들은 널리 사용되고 있는 알고리즘에 국한되어 있어 메모리의 모델이 변하게 되면 다시 메모리 모델에 따라 BIST IP를 설계해야 하는 번거로움이 있었다. 하지만 본 논문에서는 사용자가 원하는 메모리 모델에 따라 알고리즘을 적용해 자동으로 BIST IP를 생성해 주는 툴을 개발하였다. 내장된 메모리로는 리프레쉬가 필요 없는 다중-포트 비동기식 SRAM이 가장 많이 사용되며, 본 연구에서는 이중-포트 SRAM에 대하여 연구 하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1999년도 추계학술대회논문집
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• pp.333-344
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• 1999

Currently many studies on the unmanned gantry crane for the automated container terminal are accomplished. This is needed for the development of large scale, automation, high speed, unmanned system and information system in port facility. In order to do efficient container handling job in port yard, the automated handling system is well adapted to the job environments and all-season weather, In order to realize the automatic and unmanned system for container handling job, the required functions and main structure system are studied. The major problems of operation of the conventional gantry crane are that the vibration of gantry structure body is occurred by operation and that high-speed and precision position-velocity control and the capability to dope to the external disturbances caused by the wind, rain, fog and job environments. In this paper, the fundamental study for establishment of the concept and the dynamic modelling of the major sub system of the unmanned gantry crane is presented. These studies are useful for design and manufacturing of the new concept model of the unmanned gantry crane for efficient operation of the automated container terminal.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.465-470
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• 2002

A novel phased array antenna system for space-borne polarimetric SAR is proposed and completed in this paper.The antenna system assures polarimetric and multi-mode capability of SAR. It has broadband, high polarization isolation and high port to port isolation. The antenna system is composed of broadband polarimetric microstrip antenna, T/R modules and multifunction beam controller nit. The polarimetric microstrip antenna has more than 100MHz bandwidth at L-band with -30dB polarization isolation and high port to port isolation. The microstrip element and T/R module's structure and characteristics, the subarray's performances measuring results are presented in detail in this paper. A design scheme on beam controller of the phased array antenna is also proposed and completed, which is based on Digital Signal Processing (DSP) chip -TMS320F206. This beam controller unit has small size and high reliability compared with general beam controller. In addition, the multifunction beam controller unit can acquire and then send the T/R module's working states to detection system in real time.