플래쉬형 A/D 변환기를 위한 간단한 구조의 고속 비교기 설계

潘在景,方駿鎬,曺海豊 全北大學校 1992 論文集 Vol.34 No.-

A Flash A/D converter has many comparators for the high speed conversion operation, and its high performance can be achieved by the comparator with good characteristics. When the comparator is used in Flash A/D converter, the improved characteristics of the comparator are restrained by its size and power consumption. In this paper, a high speed CMOS comparator with simple architecture has been designed and simulated using a standard 1.5[㎛] processing parameter for the Flash A/D converter. The characteristics of the designed comparator are improved by using internal biasing circuits and the CMOS complementary gain stage. This comparator can be operated in a few nano second and have a small size achitecture.

AOD 와 CCD를 이용한 광학적 퓨리에 변환

潘在景 全北大學校 1991 論文集 Vol.33 No.-

In this paper, an optical Fourier transformer was composed of AOD and CCD. The resulting Fourier spectra are in good proportion to the input signal frquency and integration time T of CCD. These result show the good performance and flexibility of the optical Fourier transformer with regard to a varying bandwidth and resolution of an input signal with the integration time controlled by the computer.

효율적인 Perfect Shuffle의 광학적 구현에 관한 연구

潘在景,許賢 全北大學校 1994 論文集 Vol.37 No.-

The optical implementation of the perfect shuffle has been studied by many researchers. The efficiency is an important factor for implementation of optical multi-stage interconnection networks. In the implementation of PS, the one copy algorithm is the Dost efficient method. But until now the efficiency of grating used for one copy algorithm is low. so the performance of the system is degraded in case of constructing multi-stage interconnection networks. Therefore in this paper we propose the method of constructing of efficient optical PS and identify the increase of the efficiency of the proposed method with computer simulation. We use BQBPH algorithm for making the gratings.

광학적 영상투영 및 상관을 이용한 패턴인식에 관한 연구

潘在景 全北大學校 1993 論文集 Vol.35 No.-

In this paper, a pattern recognition technique of 2-D images using several 1-D projection correlations is introduced. The available features in 2-D image are extracted from its 1-D projection and 1-D correlations. The Optical Radon Transformer and AO(acousto-optic) correlator are applied to the processor. Three flights are used to evaluate the performance of this technique and successful simulated results are provided.

가상교육의 문제점과 개선방안

한판암,하경재 慶南大學校 附設 工業技術硏究所 2003 硏究論文集 Vol.21 No.1

현재의 가상교육이 가지고 있는 문제점을 파악하고 개선방안을 제시하기 위한 연구이다. 이 같은 목적 달성을 위하여 연구한 내용은 다음과 같다. 우선 가상교육의 실상을 파악하기 위하여 K대학에서 2002학년도 제2학기 가상교육에 참여했던 학습자를 대상으로 실시한 설문조사 결과를 분석했다. 이 분석 결과를 본 논문의 제3장에서 제시한 7가지 기준에 따라서 분류하여 문제점을 정리했다. 이렇게 도출된 문제점들은 가상교육에 중요한 역할을 하는 학습자, 교수자, 전달방법으로 구분하여 가상교육의 개선방안을 제시했다. 가상교육의 활성화를 위해서는 많은 문제점들에 대하여 개선이 필요한 형편이다. 그러므로 앞으로 가상교육의 발전을 위하여 제안된 개선 방안들은 반드시 해결해야할 과제들이다. In this paper, we analyze the existing problems on the cyber education and suggest a scheme to solve them and to improve its educational effects. In order to analyze the problems, we carried out surveys about educational effects for leaners participated in cyber classes of the 2nd semester, 2002 at the K university. The analyzed results of the surveys are arranged and classified in accordance with seven criteria proposed in section 3 of this paper. The arranged and classified results are used to suggest a scheme of improvement in educational effects of cyber classes in terms of learners, trainers and communication strategies which are key factors on the cyber education. Although it leaves much room for improvement in cyber education, our study is expected to contribute to stimulate the cyber education.

60Hz 전원동기를 이용한 스펙트럼 확산 전력선 통신에 관한 연구

許賢,潘在景 全北大學校 1996 論文集 Vol.41 No.-

Power line communication is very useful and economical for local area network, office automation, factory automation, and home automation. Electric power distribution circuits provide reasonably universal channels with a simple and standard interface in the from of a wall-socket plug. Disadvantages are limited bandwidth in comparison with ordinary communication links, high noise levels, and uncertain and varying levels of impedance. We presents the measurements of noise, attenuation, and impedance on the intrabuilding distribution circuits. Measurements were made at four different locations, such as laboratory, apartment, house, and hospital. These data are available for the design of communication systems. We consider pseudonoise(PN) modulation to overcome these impairments and present preliminary assessments of performance obtainable using a simple direct-sequence(DS) PN modem. Code synchronization is implemented by 60Hz zero crossing of the power frequency. The results have shown that data are transmitted and reconstructed well through power line up to 3kbps.

테스트 그룹을 기반으로한 SRGM의 구현

김정종,이창희,하경재,한판암 慶南大學校 附設 工業技術硏究所 1998 硏究論文集 Vol.15 No.3

소프트웨어 개발중에 테스트는 단위 및 통합 테스트는 개발 점검팀(Development Test Team), 확인 및 시스템 테스트는 독립 점검팀(Independent Test Team), 인수 테스트는 인수 점검팀(Customer Test Team)에 의해 수행된다. 그런데 테스트 그룹별로 테스트 수행방법, 절차, 도구, 노력, 요원 등이 서로 다르게 적용되고 있다. 이상과 같은 특징을 고려하여 본 논문에서는 소프트웨어 테스트 단계에서 테스트를 수행하는 테스트 그룹을 기반으로한 SRGM(Software Reliability Growth Model: 소프트웨어 신뢰도 성장 모델)을 제안한다. 그리고 실제 관측된 데이터를 기존의 지연 S자형 SRGM과 본 논문에서 제안한 테스트 그룹형 SRGM을 적용하게 위하여 최우 추정법에 의한 파라미터를 추정하고, 코무로고루프·스미루노프(Kolmogorov-Smirrnov : K-S)검정법으로 모델의 적합도 검정을 수행했다. 그리고 평균치 함수, 기대 잔존 결함수 및 소프트웨어 신뢰도를 추정하여 그 결과를 비교·분석했다. 그 결과 테스트 그룹형SRGM이 실제 데이터에 더 적합한 것으로 나타났다. Unit and integration test, validation and system test, and delivery test is performed by development test team, independent test team, and customer test team respectively in the development of software. Testing methods, procedures, tools, efforts, and man-power differ depending on the test groups. This paper proposes SRGM(Software Reliability Growth Model) based on test groups considering the above characteristics. The parameters are estimated by maximum-likelihood estimation method for the data to be applied th delayed S-shaped SRGM and test group based SRGM. The goodness-of-fit of two models is measured by Kolmogorov-Smirrnov test method. The results are analyzed and compared by estimating mean value function, expected number of remaining errors, and software reliability. The result shows that test group SRGM is fitter than delayed S-shaped SRGM for real data.

ZVS를 이용한 풀 브릿지 단일 전력단 고주파 공진 AC-DC 컨버터의 특성해석

남승식,황계호,오경섭,원재선,조규판,김동희 嶺南大學校 工業技術硏究所 2003 工業技術硏究所論文集 Vol.31 No.2

This paper proposes a single-stage high frequency resonant AC-DC converter using zero voltage switching with high input power factor. The proposed high frequency resonant converter ingegrates a half bridge boost rectifier as power factor corrector(PFC) and half resonant converter into a single stage. The input stage of the half bridge boost converter is working in discontinuous conduction mode(DCM) with constant duty cycle and variable switching frequency. Therefore, high power factor is achieved naturally. The results of simulation using the Pspice have demonstrated the feasibility of the proposed AC-DC converter. The proposed converter will be able to be practically used as power supply.

Fourier Spectrum of 2-D Image at Each Projection Angle Using Radon Transform

Pan, Jae-Kyung 全北大學校 1989 論文集 Vol.31 No.-

본 논문에서는 Radon 변환을 이용하여 2차원 영상의 투영각도에 따른 Fourier spectrum을 구하였다. 주어진 2차원 입력 영상을 Radon 변환하여 시간여역의 1차원 신호로 바꾼후 AOD와 CCD로 구성한 광학적 Fourier 변환기에 입력시켜 신호를 처리하였다. 광학적으로 구성한 Fourier 변환기는 triple-product 알고리즘에 근거하였다. 본 실험 결과는 광학적 구성의 단점인 융동성의 결여를 해결할 수 있으며, 광학적 처리방식과 전자적 처리방식을 채용한 복합 패턴인식 장치 등에 응용할 수 있다.

Fourier Spectrum of 2-D Image at Each Projection Angle Using Radon Transform

Jae Kyung Pan,Nam Kim,Han Kyu Park 대한전자공학회 1987 TENCON 87 - Computers and Communications Technolog Vol.- No.-