• Journal of Sensor Science and Technology
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• v.2 no.1
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• pp.49-56
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• 1993

This paper describes an effort of improving performances of ultrasonic ranging system using V40 microprocessor. Conventional ranging systems are somewhat inaccurate because they do not have capability of compensating changes in medium condition. The novel ranging system overcomes this disadvantage by placing a dummy sensor functioning as a standard calibrating instrument in the same medium and by providing data processing capability using V40 controller. Also data communication between V40 and personal computer via RS232C makes it possible to use the ranging system for varieties of other applications such as analysis of static and dynamic system.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.9
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• pp.958-963
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• 2012

Characteristics of off-grid hybrid renewable energy sources for high mountain villages are discussed. Considering reliability of electric power generation, Photovoltaic (PV)-wind hybrid and PV-hydro hybrid system are suggested. Connecting two or more villages with these hybrid systems, an extended hybrid off-grid can be formed. Sustainability of entire system is important in design of off-grid system, and income generation of the village people using the electricity should be considered.

• Journal of the Ergonomics Society of Korea
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• v.33 no.3
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• pp.203-214
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• 2014

Objective: This study aims to examine the psychological effects of pilots caused by the environmental differences between actual and simulated flights by measuring biochemical stress level and subjective stress level. Background: Currently, the flight system of the air force suffers from several problems including a limited training area, increase of complex and tangled missions and rise in oil prices. In order to overcome these problems an L-V-C (Live, Virtual, Constructive) training system has been proposed as a solution. However, to establish the effective L-V-C training system, it is required to figure out the characteristics of each system first. Also we have to solve the problems which could occur when these systems are connected together. Method: In order to measure the biochemical stress level of pilots, we investigated the differences in cortisol responses after actual and simulated flight training separately. Meanwhile, we conducted the questionnaire survey of about 40 pilots to identify the subjective stress level of pilots. Results: There was significant difference in cortisol level between actual and simulated flight tasks. However, we found that there was no significant difference in pilots' feelings about two flight tasks. Conclusion: The results from this study can be used as basis for the further research on not only how to decrease linkage errors of the L system and the V system but also how to make the L-V training system more practical. Application: The results of the analysis might help to develop the Live-Virtual-Constructive (LVC) pilot training system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.1
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• pp.1-7
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• 2008

In this paper, we proposed the method judging whether transmission system is radial system or loop system using simple set theory. And we proposed the method judging whether power device's operation causes of blackout or not. Using proposed method, we developed automatic judgement system of radial system for preventing power device's wrong control in SCADA. Finally, we simulated a variety of case study using SCADA simulator with developed system, and verified reliability of the result and performance of developed system.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.1
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• pp.31-40
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• 2016

In this study, mesophilic anaerobic digestion of source separated food waste was carried out by leachate recirculation system and methane gas was produced. Two systems - system A and B were fabricated and placed within water bath to maintain $36^{\circ}C$. Each system was comprised of an anaerobic bioreactor and a leachate tank. Leachate in bioreactor was separated through the screen located at 30 mm above the bottom and a pump was installed to transfer collected leachate to the leachate tank. Everyday, 2.5 L of the leachate was pumped from the bioreactor to the leachate tank for 30 min and transferred leachate was pumped back to the top of the bioreactor for 30min, sequentially. Source separated food waste used for this experiment was washed by water before transferring to the laboratory. Transferred food waste was warmed to $36^{\circ}C$ before being fed to bioreactors. System A was fed to 49.1 g VS (Volatile Solids) and System B was fed to 54.0 g VS at every two weeks, respectively. $NH_4{^+}-N$ and salinity were monitored to see the inhibition toward anaerobic bioreaction and it was found that concentrations of these materials were not high enough to affect the bioreaction. Although the food waste was fed biweekly for 112 days and 140 days at system A and B, respectively, there was no sludge withdrawal from each system. Average methane productions rates were 0.439 L $CH_4/g$ VS and 0.368 L $CH_4/g$ VS for system A and B, respectively.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.199-202
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• 1997

We are developing computer integrated polysomnography system. This system integrates conventional polysomnography with computer for data management, automatic analysis, scoring, and data transmission. In the first stage, we have developed the signal interface and user interface for the manual scoring and data management. For the automatic scoring of sleep stage, we have developed the protocol and have applied the analytic method in its primitive form. In the second stage we will develope a partially automatic scoring system, and finalize the fully automatic system in the final third stage.

• Journal of Korean Society of Rural Planning
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• v.7 no.1 s.13
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• pp.49-59
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• 2001

This study aimed at developing the through processing system of questionnaire works for public participating village appraisals. With the data-base system of standardized questions menu pool developed in the previous study, the system was developed using Visual Basic 6.0 and Access 97 and consisted of 3 subsystems; Questionnaire Design, Data-in, Analysis/Presentation. Using the system developed in this study, questionnaire works for village appraisal was carried out at the 3 sample villages and processed. The questionnaire results were compared with resources evaluation results from another past study at the same sample villages, which showed much accordance between them.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.320-322
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• 1993

In this paper, the decentralized adaptive control scheme is applied to the control of drum type boiler system. Because the scheme requires the stability of interconnections, static feedback is used to satisfy the requirement of the scheme. From a priori knowledge of the system, system parameter estimates are bounded to prevent parameter drifting. Computer simulation shows that the decentralized adaptive control is suitable for the control of drum type boiler system and robust in the presence of disturbance.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.464-467
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• 1999

Rapid progress in the modeling of biological structures and simulation of their development has occurred over the last few years. Cellular automata (CA) and Lindenmayer-system(L-system) are the representative models of development/morphogenesis of multicellular organism. L-system is applied to the visualization of biological plant. Also, CA are applied to the study of artificial life and to the construction of an artificial brain. To design the L-system and CA automatically, we make this model evolve. It is necessary to code the developmental rules for evolution. In this paper, we propose a DNA coding method for evolution the models of development/morphogenesis of biological multicellular organisms. DNA coding has the redundancy and overlapping of gene and is apt for the representation of the rule. In this paper, we propose the DNA coding method of CA and L-system.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.33-36
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• 1996

In this paper, we present the Computerized Polysomnographic System, which we developed for aiding manual polysomnographic diagnonis. This system is composed of four sub parts: patient information management tool, polysomno-graphic signal acquisition tool, signal analysis tool, and result-reporting tool. We calculated the parameters of sleep diagnosis, both on the sleep stage hypnogram and event lists. We developed this system on the Windows NT 4.0 and Pentium Pro 200Mhz. We are testing this system on the clinical site.