짧은 펄스로 구동되는 반도체 발광소자의 파장측정에 관한 연구

김경식(Kyung-Sik Kim),김재창(Jae-Chang Kim),조홍성(Ho-Sung Cho),홍창희(Tchang-Hee Hong) 한국해양대학교 해사산업연구소 1991 海事産業硏究所論文集 Vol.1 No.-

본 연구에서는 매우 짧은 전류펄스에 의해 구동되는 반도체 발광소자의 파장특성을 측정하기 위한 장치를 고안하였다. 이 장치는 600grooves/mm의 회절격자에 초점거리가 275mm인 분광기와 X-Y recorder 그리고 아날로그 분석을 위한 scanning motor와 최대값 검출기가 결합된 증폭기로 구성시켰다. 특히, 최대값 검출기는 짧은 펄스 신호를 연속적인 값으로 변환하기 위하여 사용하였다. 이 장치를 이용하여 상용화된 발광다이오드와 AlGaAs/GaAs LD및 InGaAsP/InP BH-LD를 duty cycle이 0.01인 전류펄스로 구동하면서 그 파장특성을 분석한 결과 약 1Å정도의 분해능과 10㎼정도의 수신감도를 가지는 것을 확인하였다. In this paper, a system has been propsed for the measurement of the spectral characteristic of semiconductor light sources driven by very short pluse currents. This system has been constituted a monochrometer of 600 grooves/mm grating and of 275mm focal length, X-Y recorder, scanning motor which enables the system to get the analog data, and amplifier coupled with peak detector. Especially, peak detector was used to convert the short pules signal to continuous one. In order to verify the resolution with slit width, several slits were made with hands. By using this system, thspectra of commericial LEDs, AlGaAs/GaAs LD, and InGaAsP /InP BH-LD which were diriven with pulse current (duty cycle=0.0I%) were measured. Form these measurements, it has been shown that the proposed system has about 1Å Resolution and 10㎼ resolution and 10㎼ sensitivity.

2영역 모델을 이용한 선박용 디젤기관의 NO 생성농도 예측에 관한 연구

정영훈(Young-Hoon Jung),최재성(Jae-Sung Choi) 한국해양대학교 해사산업연구소 2000 海事産業硏究所論文集 Vol.10 No.-

오늘날 대기오염과 지구 환경에 대한 관심이 고조됨에 따라 대기오염을 유발하는 배기 배출물에 대한 규제가 본격적으로 시작되면서 인체에 유해한 배기 배출물 즉 질소산화물 (NOx)과 미립자와 같은 유해배기가스의 저감을 위한 연구가 활발하게 진행되고 있다. 본 논문에서는 대형저속박용디젤기관의 NOx 발생에 관한 기초연구로서 연소실내의 연소과정에서 생성되는 NO 농도의 조성을 예측할 수 있는 프로그램을 개발하여 질소산화물의 배출농도를 정량적으로 예측하고, 예측결과와 박용엔진에서 실제 계측한 결과를 비교함으로써 정량적 예측방법에 관하여 검토하였다. Diesel engine is a major source of the air pollution. In general, the concentrations of these pollutants in diesel engine exhaust gas differ from values calculated assuming chemical equibrium. Thus the chemical mechanisms about these pollutions form are important in determining emission levels. In this study, the computer program has been developed to calculate the required thermodynamic properties of combustion products (10 spacies) for both equilibrium and non-equilibrium in cylinder for diesel engines. Nitric oxide emissions are calculated by using the extended Zeldovich Kinetic mechanism. By the results, the predictions show well the general trend in NO emission behaviour for Marine diesel engine when compared with experiment.

컨테이너 크레인 시뮬레이터 개발을 위한 환경설정에 관한 기초연구

소명옥(M. O. So),최한우(H. W. Choi),이윤형(Y. H. Lee),윤학진(H. J. Yeun),최재준(J. J. Choi) 한국해양대학교 해사산업연구소 2003 海事産業硏究所論文集 Vol.14 No.-

The skill of the crane operator has influence on the overall profitability of a transport. But, It is very hard to train crane operators effectively by actual crane. Therefore, it is desirable for the crane simulator to be used properly, considering various condition of the crane operation. The purpose of the container crane simulator is to provide a facility for training and evaluation of crane operators and aspirants. Training using crane simulator provides crane operators with the increased safety and high efficiency. Hence, as the basic study on crane simulator, this paper introduces developers the kinds of training education programs and the setting up of environmental conditions for virtual reality crane simulator.

유용미생물의 종류별 선박 주방폐기물의 냄새저감에 관한 연구

김인수(In-Soo Kim),김동근(Dong-Geun Kim),고성정(Sung-Jeung Ko) 한국해양대학교 해사산업연구소 2002 海事産業硏究所論文集 Vol.12 No.-

In accordance with the 'Regulations for the prevention of pollution by Garbage from ships', ship's food waste should be dumped at an area farther than 12 miles away from a nearest land. But during a ship's anchoring, food wastes gathered for the time being make residence uncomfortable owing to the rotten odor. In order to observe the EM's efficiency of odor reduction, we have fermented food wastes with EM for 2 weeks, varying the quantity, kind and procedure of EM enzyme, the below conclusions were obtained. 1) Using EM, Degree of odor is 1- 2˚ like alcohol smell. Not using, Degree of odor is 4 - 5˚ like rank odors. 2) The degree of efficiency of odor reduction is much according to kinds and quality of EM, but little according to the quantity of EM(0.3~3.0%). 3) EM mixed rice bran and chaff is more effective than general EM and show high density of enzyme microorganisms. 4) At the moment liquid from food wastes is soaked out, should be removed because it spread odor by rapid rottenness. 5) As EM itself have deodorant action, it can remove odor not using a deodorant. 6) The efficiency of odor reduction is too enough, even if EM enzyme is scattered and pressed, not mixed with food wastes.

합리적인 여성해기사 보호제도에 관한 연구

이윤철(Lee Yun-Cheol) 한국해양대학교 해사산업연구소 1999 海事産業硏究所論文集 Vol.9 No.-

Women are allowed to come on board, substantially, as officers in Korea from the year of 1995. The protective system for female officers is not enough yet. Though the number of female officers is increasing slowly, we need to have a reasonable and logical system to protect them. The biological difference between men and women is very big, so the protective system for motherhood is a simple way to admit the difference. We still have wrong general idea about woman and motherhood to understand the protective system. Therefore, it should be considered and changed by developing scientific technology. To protect woman and make a reasonable system for female officers. we have to change the general idea about them and agree that they are just human and have the equivalent right to male officers. I tried to suggest a system through the comparative study of domestic and international systems in this paper. In conclusion, I think the protective system for female officers has to be changed reasonably and reformed to protect the motherhood. And it should contain the same right between male and female officers as a human being.

선박엔진 통합시스템의 실시간 고장진단 기법에 관한 연구

정경열(K.Y.Chung),김달현(D.H.Kim),류길수(K.S.Rhyu) 한국해양대학교 해사산업연구소 1999 海事産業硏究所論文集 Vol.9 No.-

This paper presents the diagnostic method of an integration system where both diagnosis system and monitoring system are combined. Knowledge base for ship engine fault diagnosis is implemented using hybrid knowledge representation technique by EE(Element Expert) shell, and using a certainty-factor method to handle uncertainties of evidences and rules. Whenever alarm occurs, the monitoring system sends alarm data to the diagnosis system. At the same time, the diagnosis system converts alarm data type to diagnosis data type, verifies alarm data, and calculates data's trend. To map alarm data to evidences of knowledge base, the diagnosis system uses two databases. The real-time diagnosis results are provided by a reasoning mechanism implemented using visual C++ for driving OLE automation server of EE shell.

선박용 발전기관의 배기배출물에 관한 실험적 연구

조권회(Kwon-Hae Cho),이진욱(Jin-Uk Lee),이상득(Sang-Deuk Lee) 한국해양대학교 해사산업연구소 2004 海事産業硏究所論文集 Vol.15 No.-

The internal combustion engine has been widely used as power source, such as vehicles, industrial machine, power plant, military and marine engine. etc.. Especially, diesel engine has come to occupy most of engines for marine use, due to high thermal efficiency, durability, reliability and high output. But, the exhaust gas emissions of diesel engine came to be considered the major pollutional source, like the destruction of ozone layer, global warming, acid rain and photochemical smog, etc. Therefore, IMO adopted the regulations for the prevention of air pollution from ships as MARPOL 73/78 Annex Ⅵ in September, 1997 and this convention will be effectuated on May 19. 2005. But the restriction for NOx is applied to each diesel engine with a power output of more than l30㎾ which is installed on a ship constructed, which undergoes a major conversion on or after 1 January 2000. In this study, the generation mechanism was investigated for various exhaust gas emissions in diesel engine. And the emission characteristics of exhaust gas was understood for generating diesel engine.

도허티 이론을 이용한 전력증폭기의 효율 향상에 관한 연구

전중성(Joong Sung Jeon),예병덕(Byeong Deok Yea) 한국해양대학교 해사산업연구소 2004 海事産業硏究所論文集 Vol.15 No.-

In this paper, Doherty amplifier is designed by the need of improving the linearity and efficiency of wireless network and repeater for WCDMA. It is designed to maintain the high linearity and efficiency at the low efficiency period of the power amplifier after analyzing Doherty technique using the active load-pull in condition of the high efficiency power amplifier implementation according to the variation of input power. CW 1-tone experimental results at the WCDMA frequency 2.11~2.17 ㎓ shows that Doherty amplifier, which achieves power add efficiency(PAE) 50 % at 6 ㏈ back off the point from maximum output power 52.3 ㏈m, obtains higher efficiency of 13.3 % than class AB. Finding optimum bias point after adjusted gate voltage, Doherty amplifier shows that IMD₃ improves 4 ㏈.

다국적기업의 판매촉진전략에 관한 비교분석

신한원(Han-Won Shin) 한국해양대학교 해사산업연구소 1993 海事産業硏究所論文集 Vol.3 No.-

L-band의 위성통신 시스템을 위한 극소형 25 Watt 고출력증폭기에 관한 연구

이영섭(Young-Sub Lee),전중성(Joong-Sung Jeon),홍창희(Tchang-Hee Hong) 한국해양대학교 해사산업연구소 2001 海事産業硏究所論文集 Vol.11 No.-

The 25 Watt hybrid MIC SSPA has been developed in the frequency rang from 1.6265 GHz to 1.6465 GHz for uplink of INMARSAT's earth station. To simplify the fabrication process, the whole system is designed of two parts composed of a driving amplifier and a power amplifier. The Motorolas MRF-6401 is used for driving part, the Motorolas MRF-16006 and MRF-16030 is used the power amplifier. We reduced weight and volume of high power amplifier through arranging the bias circuits in the same housing. The realized SSPA has more than 30 dB for gain within 20 MHz bandwidth, and the voltage standing wave ratios(VSWR) of input and output port are less than 1.7, respectively. The output power of 44 dBm is achieved at the 1 dB gain compression point of 1.6365 GHz. These results reveal a high power amplifier of 25 Watt which is the design target. The Proposed SSPA manufacture techniques in this paper can be applied to the implementation of high power amplifiers for some radars and SCPC.