• 한국통신학회논문지
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• 제14권6호
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• pp.611-620
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• 1989

본 논문에서, PC를 이용하여 개인을 확인할 수 있는 지문정합에 관한 방법을 논하였다. 지문정합법에서 첫째, 지문영상을 세션화하고 단점과 분기점의 위치와 방향으로 구성된 특징점을 추출한다. 지문식별은 추출된 데이터를 이용하여 참조지문과 입력지문의 일치 또는 불일치 판정으로 수행된다. 평활화와 2진화처리, 세션처리후에 세션영상은 정확한 특징량의 추출을 위해 복원처리를 행한다. 정합시에 참조지문과 입력지문사이의 단점과 분기점 위치를 평행이동과 회전이동에 의하여 보상하여 지문확인을 수행한다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.333-343
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• 2000

An automatic guidance system for combine was designed to harvest paddy rice by following a predetermined path. The automatic guidance system consisted of DGPS to locate position of combine, a gyro sensor system to measure heading angle, ultrasonic sensors to detect obstacles, a hydraulic system, microcomputer as a controller, and I/O interface system. Hydraulic cylinders and valves were installed to control movement of the combine. The heading angle and the position of the combine, and ultrasonic measurements from edge were used as the inputs of the controller. The operating position of hydraulic cylinder was determined as output of the controller. The automatic guidance system was evaluated at the 45-m straight path by changing the posture of the combine. The average RMS errors were 14.0 cm without offset and 15.0 cm with 1-m offset. The DGPS provided accurate position information within the limited error to guide the combine in the field. The results showed that the automatic guidance system could guide the combine autonomously in the paddy field when the posture of the combine was changed.

• Journal of Biosystems Engineering
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• 제21권2호
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• pp.123-133
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• 1996

An automatic drum seeder was developed to improve the seeding operation. It consisted of a conveyor to transfer seedling trays, a seed-hopper to supply seeds, a drum to drop seeds on the tray, and an air blower to remove extra seeds. A photo sensor was used to detect the transfer of seedling trays, and its signal was fed into microcomputer which operated a stepping motor driving the drum. The seeds were adhered to the surface of drum by vacuum pressure, and were dropped into tray cells by compressed air. An air connection unit was devised to alternate between vacuum pressure and compressed air. A control program for the system, written in C language, could operate the drum at the given number of revolutions and revolutions per minute. The results showed that the air connection unit could operate well and the seeds were dropped satisfactorily into tray cells. In case of cabbage and perilla seeds, which are regular and spherical shape, the missing rate was low and the single seeding rate was more than 97%. Low missing rate and high multiple seeding rate were observed in lettuce seeds which have narrow ends with tight weight. The missing rate of pepper seed was very high because of heavy weight and irregular shape. To improve the performance of the seeder, adjustment of vacuum pressure based upon shape and weight of the seeds, careful selection of the material of drum, maintenance of consistent air blower pressure, and replacement of stepping motor to DC motor are recommended.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1991년도 추계학술대회
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• pp.142-144
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• 1991

In this study, we have developed 64 channel computerized cardiac mapping system using micro-computer for basic research of electrophysiology and electrical propagation in cardiac arrhythmias. The significant problems of this study are the simultaneous acquisition of large amount data at 64 sites, the need of accurate and rapid analysis, and the effective display of the analyzed data. To solve these problems, we made 64 channel signal pre-processing board in order to amplify and filter the raw signals. And the software for cardiac isochronous mapping which were presented immediately via computer-generated graphics has been developed. This system is expected to enable us to study pathophysiology of cardiac arrhythmia and to improve the results of diagnosis and surgical treatment for cardiac arrhythmia.

• 수산해양기술연구
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• 제29권3호
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• pp.183-190
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• 1993

A cooperative Korea-Japan investigation for the demersal fisheries resources of the East China Sea carried out by using the training ship Oshoro Maru belong to Hok-kaido University, Japan, during 1-8 November, 1991. The research vessel sampled 15 stations with demersal trawls on the East China Sea, and 1,364 nautical miles of track line were surveyed hydroacoustically. The hydroacoustic observations were taken with a scientific echo sounder operating at two frequencies of 25 kHz and 100 kHz, and a microcomputer-based echo integrator. Fish samples were collected by demersal trawling, and temperature, salinity and dissolved oxygen were measured with a CTD system. The target strength of fish school was estimated from the relationship between mean scattering strength and catches caught by demersal trawling. The results obtained can be summarized as follows: 1. The mean backscattering strength for 15 layers occupied by demersal trawls at 25 kHz ranged from -70.4 dB to -59.1 dB. Then the catch per one hour ranged from 8.2 to 587.5 kg/hour. 2. The mean backscattering strength for the entire layer between transducer and seabed in the survey area of the East China Sea at 25 kHz and 100 kHz were -68.0 dB and -73.1 dB, respectively. 3. The mean fish-school target strength per one kilogram at 25 kHz and 100 kHz were -28.3 dB/kg, and -30.4 dB/kg, respectively.

• Korean Journal of Hydrosciences
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• 제2권
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• pp.99-113
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• 1991

Integrated irrigation management system (IIMS) that is incorporated with a microcomputer-based decision support system (DSS) has been developed and applied to paddy rice irrigation systems management. The system hardwares consist of field data acquisition units, data transmission units, central data processing units, and printing and displaying units. Ridld data to be collected include incremental rainfall, streamflow and reservoir water levels, and water levels at several irrigation canal sections within an irrigation sidtricts. The softwares are to process field data, real-time forecasting, irrigation control data, and decision variables from data-base and simulation model subsystems. And the user-interface subsystems are incorporated to present the water system operators and managers the results from data and model sugsystems. User-friendly menu with animated graphic modules are adopted to help understand irrigation controls for the district. This paper issues the overal descriptions of DSS as applied to Anjuk irrigation district. The details of major model components for the irrigation controls are presented along with real-time data collection systems. The potentials of DSS have been appraised very practical and promising for better irrigation system operation and management.

• Journal of Biosystems Engineering
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• 제18권4호
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• pp.328-343
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• 1993

To control depth of tractor implement, an automatic depth control system based upon microcomputer was developed. This system consists of data aquisition system to measure and to record travel speed, draft and depth of the implement, hydraulic system to control the implement depth and 3-point hitch to attach the implement. Program, written in C language, was able to select position control, draft control and mixed control. To analyze parameters affecting this system, the performance of the system was evaluated through use of computer simulation and verified in soil bin experiments. 3-point hitch was lifted by hydraulic pressure and lowered by implement weight. Dead band was one of the important factors which affect the stability and the accuracy of the system. The system became unstable when the flow rate was increased or when the dead band was decreased. The position control mode with on-off control showed the great ability to control the implement at the given plowing depth. With the draft control, the tractor load could be reduced, however the plowing depth was changed unexpectedly when the soil was hard and inconsistent. The mixed control could improve the performance of the system to maintain the plowing depth without overload of the tractor.

• Journal of Radiation Protection and Research
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• 제12권1호
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• pp.12-25
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• 1987

SA(Successive Approximation)형 ADC(Analog to Digital Converter)를 사용하여 방사선다중채널파고 분석기를 설계 제작하였다. 선형게이트, 윈도우 및 펄스스트레처는 논리 IC와 선형 IC들을 위주로 결합하여 구성하였으며, 분석시간이 $120{\mu}sec$인 ADC 1211(12 bit)을 중심으로 한 ADC 모듈의 메모리로는 S-RAM 6264 (Address 13 bit, Data 8 bit) 2개를 병렬로 연결하여 사용하였다. 마이크로 컴퓨터 (Apple II)가 전체 시스템을 제어하고 또 계측된 결과의 데이타를 분석할 수 있도록 인터페이스와 소프트 웨어도 만들었다. 제작된 시스템의 동작시험은 표준펄스 발생기로 $0{\sim}10V$ 사이의 일정한 펄스를 만들어 시스템에 입력시켜 그 펄스들을 계측하게 하고, 계측이 끝난 후 컴퓨터가 그 결과를 받아들여 분석하게 함으로써 이루어졌다.

• 전산구조공학
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• 제2권4호
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• pp.69-77
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• 1989

최근까지만해도 유한요소 모델의 그래픽 후처리는 주로 대형컴퓨터와 이에 수반되는 고가의 도화장비에 의존할 수 밖에 없었다. 그러나 우수한 그래픽 기능을 갖춘 저렴한 소형컴퓨터의 등장에 힘입어 대단히 경제적인 후처리 그래픽 프로그램인 MICRO-POST가 개발되었다. 이 프로그램을 이용하여 무제한 요소망으로 이루어진 대형 유한요소 모델의 기하형태나 해석결과를 각종 저가의 도화장비에 호환하여 도화처리할 수 있게 되었다. 본 논문에는 도화장비의 호환을 위한 프로그램 절차와 프로그램의 구성 및 그 기능들을 기술하였다. 또한 소형컴퓨터의 메모리 용량 극복을 위한 효율적인 I/O 기법과 도화처리를 교호 작용하면서 관리할 수 있는 대화형식의 입력방식도 기술하였다. 범용 유한요소해석 프로그램에 접속시킨 이용사례를 통하여 프로그램의 효율성을 입증하였다.

• 유공압시스템학회논문집
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• 제2권2호
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• pp.8-13
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• 2005

This paper investigates a fast, accurate and inexpensive hydraulic motor speed control system using high speed on-off solenoid valves. In order to retain the advantages of the two position valve and obtain better performance, the valves are operated by pulse width modulation(PWM) control. PWM signal is generated from a LabWIEW program in microcomputer in order to set up various duty ratio and frequency of carrier wave in PWM signal with varying system parameters. As the results of experiments, the speed control of a hydraulic motor was successfully implemented using on-off solenoid valves. In order to attenuate the pressure ripple and speed variation due to discontinuously controlled flow through the on-off valves, a resonator hose fabricated for automobile power steering system was connected between the valve and a hydraulic motor. From experimental results obtained in the hydraulic motor system with a resonator hose, it was ascertained that the resonator hose showed excellent performances in reducing pressure ripple and motor speed variation.