CDMA 시각 동기용 GPS 시스템의 고주파부 설계 및 제작

홍성일,김영민,변건식 東亞大學校 附設 情報通信硏究所 1996 情報通信硏究所論文誌 Vol.4 No.1

When GPS(Global Positioning System) is used as synchronous signal in CDMA digital cellular base station system and high speed digital synchronous communication network, antenna cable lengh is increased, comparing with other GPS application such as positioning or car navigation. In this paper, it is proposed that a type of new GPS antenna system including RF stage for reduction of cable loss in case of long cable. The antenna system with TMPA(Truncated-corners Microstrip Patch Antenna) is designed and fabricated because GPS signal has RHCP(Right-Hand Circular Polarization), consequently antenna size can be made small size. NAN(Low Noise Amplifier) is designed by using HEMT(High Electron Mobility Transistor) which has lower noise figure and better AGC characteristics at low voltage than GaAs FET, and we equipped mixer, in GPS antenna unit, which converts from 1575.42MHz to 75.42MHz. As result of comparing between typical system and proposed system when cable length is 60m, 63dB, 55dB and 25dB gain are obtained for RG-316/U, RG-58C/U and RG-213/U, and better characteristics are achieved than typical system as far as cable length is longer.

GPS 동기신호 수신기 개발 : 중간 주파수단과 데이타 추출

홍성일,이수영,박재운,변건식 동아대학교 공과대학 부설 한국자원개발연구소 1993 硏究報告 Vol.17 No.2

This paper concerns IF-stage and data recovery as a basic study for home products of GPS receiver. Using a transmission simulator, the same data can be received as transmission simulator transmits. Consequently, it is considered that IF-stage and the part of data recovery operate fairly good and attaching microprocessor control and time interval counter to this system will operate better. It can be expected that providing the system with RF-stage and antenna will be complete GPS receiver.

대용량 어휘를 기반으로 한 화자의 적용 알고리즘

홍승준,권영헌,이건상 한양대학교 이학기술연구소 2001 이학기술연구지 Vol.3 No.-

화자독립인식기의 평균적인 성능은 좋더라도 사용하는 화자에 따라 인식률이 많이 차이가 난다. 이러한 문제점을 해결하기 위한 방법으로 본 논문에서는 기존의 codebook을 사용하여 사용자의 적은 어휘로써 높은 인식률을 가질 수 있는 화자 적응 방법을 제안한다. 본 논문에서는 대용량 어휘인식을 위해 음소인식에 뛰어난 성능을 지닌 CHMM(continuous hidden Markov model)을 사용하였고, 적응 알고리즘인 MAP(maximum a posterior)를 사용하여 HMM의 파라미터를 적응시키는 방법으로 대용량 어휘 인식률을 계산하였다. 화자 적응 알고리즘을 적용하기 이전과 화자 적응 알고리즘을 적용했을 때 인식률을 비교하였을 경우 음소 인식률이 40%이상 좋아짐을 알 수 있었다. In this paper. we propose a speaker adaptation algorithm. We make an experiment using CHMM which shows good performance for phoneme recognition. MAP formulation is developed to adapt the characteristics of speaker with the estimation of the HMM parameter from the training data. The proposed adaptation algorithm is evaluated in large vocabulary continuous speech recognition. In the experiment. we compare the recognition accuracy of the adapting acoustic model with that of common speaker. At the experimental results. MAP algorithm achieve up to about 40% additional reduction of error in phoneme recognition.

Q 不變 能動 R 共振器

洪昌熹,金斗泳,邊健植 동아대학교 공과대학 부설 한국자원개발연구소 1981 硏究報告 Vol.5 No.2

A method that simulate a series resonator of one port network when op amp is a integrator of one pole roll of with a frequency characteristics of 6 ㏈/octave roll off but it is not a ideal VCVS is proposed. the proposed resonator that constructed with only resonators and two op amps was designed by using SFG and Sensitivity is good as be low 1.

BER을 경감하기 위한 직접파와 지연파를 분리, 합성하는 시스템

洪性一,邊健植,鄭宗宇,朴在云 東亞大學校 附設 情報通信硏究所 1993 情報通信硏究所論文誌 Vol.1 No.1

본 논문에서는 다중 경로에 따른 수신신호의 노화, 특히 이동통신에 대해서 문제가 되는 페이딩 대책으로 직접파와 지연파를 분리, 합성하는 적응 배열 안테나 시스템을 제시하고 분리된 직접파 출력 또는 지연파 출력만을 이용하는 시스템보다 두 신호를 합성한 시스템의 BER이 개선됨을 제시하였다. 시뮬레이션을 행한 결과 적응 배열 안테나가 적절히 동작하는 상황에 대해서는 분리된 출력을 적응적 Weight 조정을 하여 합성함으로써 직접파만을 이용하는 것보다 오율이 향상됨이 확인되었다.

화자 식별과 얼굴 인식을 이용한 대규모 보안 시스템

홍승준,구자윤,권영헌,이건상 한양대학교 이학기술연구소 2000 이학기술연구지 Vol.2 No.

본 논문에서는 화자 식별과 얼굴 인식을 이용하여 대규모 보안 시스템을 개발하였다. 인식 에러를 줄이기 위해 전 처리 화자 식별기로 DHMM(Discrete hidden Markov Model)을 사용하였고, 후 처리기에서는 얼굴 인식을 위해 신경망을 사용하였다. Visual C++MFC을 사용하여 Sound Card와 Digital camera를 제어하였다. 그리고 본 논문에서 개발한 프로그램을 사용하여 실시간으로 실험하였다. 본 논문에서 인식에 사용한 특징 벡터로는 Filter bank energy, LSF와 Cepstrum coeffient이고, 얼굴 인식의 대표 벡터는 2차원 Filter bank energy를 사용하였다. 실험에서 사용된 사람은 학교에서 무작위로 83명을 선택하였다. Test를 위해 2049개의 음성 데이터와 365개의 얼굴 이미지를 사용하였다. 복합 모델로 구성한 본 시스템은 등록화자에 대해 98.8%의 Access rate와 비 등록화자의 99.82%의 deny rate을 나타내었다. In this paper, we developed the large scale security system using speaker identification and face recognition. In order to reduce the recognition error we used DHMM(Discrete Hidden Markov Model) in speaker identification for pre-processor and neural network in face recognition for post-processor. To test the on-line performance of total system we directly controlled the sound card and the digital camera in the environment of Visual C++MFC. And we developed the program to test the performance of the system in real time. We used filter bank energies, LSF and cepstrum coefficients as the feature vectors of speech, and the 2-dimensional filter bank energies extracted in the range of the representative feature on face. In experiments, we randomly selected 83 persons in school, and then chosen 10 persons as an enrolled person and 73 persons as a non-enrolled person. So we tested 2049 speech data and 365 image data. It turned out that the hybrid system would have 98.8% access rates for the enrolled persons and 99.82% deny rates for the non-enrolled persons.

Kartagener's Syndrome의 1例

홍순표,정복기,조건국 조선의대 1983 The Medical Journal of Chosun University Vol.8 No.1

Kartagener's Syndrome의 1예

홍순표,정복기,조건국 朝鮮大學校 附設 醫學硏究所 1983 The Medical Journal of Chosun University Vol.8 No.1

Kartagener's syndrome is a rare disease, characterized by situs inversus, sinusitis, dextrocardia and bronchiectasis. This is a report of a rare case of kartagener's syndrome in 20-year-old-male whose chief complaint was purulent sputum, rhinorrhea, & exertional dyspnea. Chest P-A view revealed the dextrocardia and the magenblase in the right subphrenic area, suggesting situs inversus totalis. Multiple small cystic radielu-concies are also seen in lower halves of both thorax, suggesting bronchiectasis. P.N.S view revealed the homogenous increase-d density in all sinuses, tut didn't clear bony destruction. Bronchogram revealed the saccular and tubular dilation of the segmental bronchi in all bronchi, Particularly in the right lower lobe bronchus. EKG finding was alternation of voltage, right atrial hypertrophy and dextrocardia.

General Priessmann 技法에 의한 開水路 不定流 解析

朴在弘,韓健淵 경북대학교 산업기술연구소 1993 産業技術硏究誌 Vol.21 No.-

Numerical instability of Preissmann scheme is studied for unsteady flow analysis in open channel. The solution strategies to the instability problems are presented in this paper. The main causes of numerical instability of Preissmann scheme are mixed flow, abrupt change in cross section, inappropriate roughness coefficients, time-distance step, rapidly rising hydrograph, dry bed and so on. To overcome these difficulties, general Preissmann model is developed by introducing distance weighting factor(Φ) and the scheme has more dissipative characteristics than existing Preissmann scheme. Verification with the observed data of a natural channel is required in the future. This model presented in this study is expected to contribute to floodwave analysis using Preissmann scheme.

콘크리트의 水密性에 關한 實驗的 硏究 : 高爐水碎 슬래그를 잔骨材로 하고 減水材를 混合使用한 콘크리트를 중심으로 Focused on using Mixedly Water Cooled Blast Furnace Slag as a Fine Aggregate and Water Reducing Admixture

黃弘淳,朱永根 大田産業大學校 1994 한밭대학교 논문집 Vol.11 No.0201

This thesis aims to stuffy and analyze the strength and permeability of concrete in order to see the suitability in general structure in using water cooled blast furnace slag produced from the iron industry as a fine aggregate. Under the similar condition of workability, in the 14th day of curing period, there is the difference about 3.4% in compressive strength between the general concrete and water cooled blast furnace slag concrete, but in the 28th day of curing period, there is no big difference between them. the permeability relations of concrete is almost same in W/C 45%, 55% and in W/C of 65% water cooled blast furnace slag concrete is more permeable than general concrete. And the result of using mixedly water reducing admixture is that the unit volume of cement is reduced about 8% and 20% of permeability effect.