• International Journal of Precision Engineering and Manufacturing
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• v.7 no.2
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• pp.18-24
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• 2006

This paper proposes a LuGre Model-Based Neural Network (MBNN) friction compensation algorithm for a linear motor stage. For matching the friction phenomena in both the motion-start region and the motion-reverse region, the LuGre dynamic model is employed into the proposed compensation algorithm. After training of the model-based neural network is completed, the estimated friction for compensation is obtained. From the obtained result we find that the new structure gains advantage over the non-friction compensation system on the performance of the compensator in both regions. The proposed compensator is evaluated and compared experimentally with an uncompensated system on a microcomputer controlled linear motor tracking system in the final section of the paper. The experimental results show the improvement on the maximum velocity error and the root mean square tracking error in the motion-start region ranges from 34% to 53% and from 53% to 75% respectively, and in the motion-reverse region from 48% to 65% and from 79% to 90% respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.6
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• pp.611-620
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• 1989

In this paper, Fingerprint matching method which is able to confirm one's identity using microcomputer is discussed. In matching method, fingerprint image is thinned and we extracted feature point data which is composed of position and direction of end-point and branch-point. Identification is conducted by decision of disagreement between reference finger print and input fingerprint us ing this extracted data. After averaging and binariztion process, thining method is conducted. Restoration process is carried out to seek precise feature pointdatd. We compensate position difference of reference fingerprint and input fingerprint, which is divied end-point and branch-point, and translated and rotated its position. Using this compensdate difference of position, we decide whether fingerp-print identity is true or not.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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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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• v.21 no.2
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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.

• Proceedings of the KOSOMBE Conference
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• v.1991 no.11
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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.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.29 no.3
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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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• v.2
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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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• v.18 no.4
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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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• v.12 no.1
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• pp.12-25
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• 1987

A basic multichannel analyser (MCA) system have been designed and constructed with the successive approximation type ADC (Analog to Digital Converter). Linear Gate, window, and palse stretcher consist of mainly linear and logic IC's, and are properly combined together to achieve short dead time and good linearity of the system. ADC 1211 (analysing time: $120{\mu}sec$) and S-RAM (static random acess memory) 6264 are used in ADC module. Two 6264 memories are connected in parallel in order to-provide enough counting capacity ($2^{16}-1$). Interfaced microcomputer Apple II controls this system and analizes the counted data. The system is tested by input pulses between 0V to 10V from oscillator.

• Computational Structural Engineering
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• v.2 no.4
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• pp.69-77
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• 1989

Until recently post-processing of finite element model has been heavily relied on expensive graphic peripheral devices. With the aid of inexpensive microcomputers, very economical post-processor graphics program called MICRO-POST has been developed. Model geometry or results of analysis for the unlimited meshes can be easily presented in a number of low-cost graphic devices. The paper presents the procedure obtaining the device-independent graphics, and the structure and functions of the program. It also describes efficient I/O scheme to overcome the memory limitation, and dialogue-type input technique to control the plot operation in an interactive manner. Through the post processing examples for the general purpose finite element programs, it demonstrates the usefulness of the program.