• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.346-349
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• 1996

In this paper development of a CAD of control systems is introduced which enables us to do not only analysis of control systems, design of controllers but also real-time implementation of controllers. By utilizing this software, the control engineer is able to repeat the procedure of modification of controllers and experiments without recompile to attain better performance. The software also offers the facility to update the parameters of controllers without stopping real-time control, which helps on-line tuning of controllers. If some parameters of the controller is changed on-line, the control input may change discontinuously. It has serious effect on the control systems. A method for on-line tuning of state feedback controller with state observer is proposed and verified through the experiment with an inverted pendulum.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.8
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• pp.994-1001
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• 2018

In this paper, to studied about future power system construction using PSS / E-Python API. Python-based future system automatical construction methods and modeling of renewable sources. it confirmed the stability of the powert system for each renewable area by calculating the weighted short circuit ratio (WSCR) index. it calculated the short circuit ratio (SCR) and selected the transmission line linkage scenario to improve the stability of vulnerable areas. it confirmed the WSCR index improvement through the selected transmission line linkage of scenario, and analyzed the stability of the renewable power system applying the scenario. It describes Facts and Shunt devices adjustment for the load flow convergence. It describes the stable methed of the bus voltage through the transformer Ratio Tap adjustment. By performing PSS/E ASCC using the Python it was performed three-phase short circuit fault capacity analysis, it is confirmed whether excess of the fault current circuit breaker capacity. In order to contingency accident analysis, it have described the generation of one or two line list of each areas using the Python. The list is used to contingency analysis and describe the soluted of the transmission line overload through comparison before and after adding the scenario line.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.230-235
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• 1997

During laser welding, a laser induced matal vapour and plasuma is formed. The plasma shows strong fluctuation combined with acoustic sound emission. On-line monitoring of the process is possible by measuring and analysing the plasma and acoustic sound emission. This paper introduce the method of on line process monitoring in the laser beam welding and analysis being monitoring signal. The results show the complementary information on the process.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1515-1524
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• 2008

In this study, railway accidents from constructing or maintaining works on/near operating line were reviewed during 2005-2007 years. Causes and hazards analysis of these accidents was performed to make an accident scenario for risk assessments. And the risk of worker casualty on/near operating line was quantitatively assessed. Also a constitution method of Risk Matrix for manage tolerable risk level was proposed.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.3
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• pp.174-179
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• 2005

This paper presents 3D line segment extraction method, which can be used in generating 3D rooftop model. The core of our method is that 3D line segment is extracted by using line fitting of elevation data on 2D line coordinates of ortho-image. In order to use elevations in line fitting, the elevations should be reliable. To measure the reliability of elevation, in this paper, we employ the concept of self-consistency. We test the effectiveness of the proposed method with a quantitative accuracy analysis using synthetic images generated from Avenches data set of Ascona aerial images. Experimental results indicate that the proposed method shows average 30 line errors of .16 - .30 meters, which are about $10\%$ of the conventional area-based method.

• Journal of Broadcast Engineering
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• v.25 no.1
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• pp.48-57
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• 2020

Recently, with the rapid development of image recognition technology, the demand for object analysis in road CCTV videos is increasing. In this paper, we propose a method that can adaptively find the counting line for traffic analysis in road CCTV videos. First, vehicles on the road are detected, and the corresponding positions of the detected vehicles are modeled as the two-dimensional pointwise Gaussian map. The paths of vehicles are estimated by accumulating pointwise Gaussian maps on successive video frames. Then, we apply clustering and linear regression to the accumulated Gaussian map to find the principal direction of the road, which is highly relevant to the counting line. Experimental results show that the proposed method for detecting the counting line is effective in various situations.

• Journal of the Korean Society of Costume
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• v.58 no.2
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• pp.162-180
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• 2008

The purpose of this study is to find the basic design factors that affect the changes in body surface lines caused by lower limb movements, thereby resulting in slacks that fit well regardless of whether the human form is static or in motion. Using unmarried female university students aged 18-24 as subjects, a total of 32 body surface lines (15 body surface total lines and 17 body surface segment lines) were measured in one static and 9 movement poses, The analysis first involved the calculation of the expansion and contraction rates per body part in body surface line in 9 lower limb movements, Second, a factor analysis was conducted using the expansion and contraction rates of these changes in body surface line. The results of this study are as follows, According to the factor analysis, basic design factors that affect changes in body surface lines comprised 8 types of factors as illustrated in fig, 2-fig, 9, which explained 79.2% of total variate for the variables studied, Factor 1, comprising the lower segment of center back leg line, center front leg line and inner leg line, and lower limb girth except midway thigh girth and ankle girth below hip girth, accounted for 30.3% of total variance, Factor 2, comprising waist girth, the total and upper segment of center back leg line and center tront leg line, and front and back segment of crotch length, explained 17.4% of total variance, Factor 3, the total and upper segment of lateral leg line at the center, accounted for 56.5% of total variance in accordance with Factors 1, 2, and 3, Factor 4 was the contracting upper part of lower leg between legscye girth and midway thigh girth, Factor 5 comprised the total and upper segment of inner leg line and posterior knee girth, Factor 6 was the total crotch length, Factor 7 was the ankle girth, Factor 8 was the abdomen girth.

• The KIPS Transactions:PartA
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• v.9A no.4
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• pp.563-572
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• 2002

A performance monitor is indispensable to trace and evaluate performance of a program under distributed processing environment. A performance monitor il classified as off-line and on-line according to its output method. An off-line performance monitor analyzes its performance after a program terminates, and an on-line performance monitor analyzes its one while a program runs. Therefore, the on-line function is essential to analyzing and debugging the program fast. JaNeC, distributed processing environment that is implemented in Java, contains an off-line performance monitor for this. However, this performance monitor may not analyze the program running on JaNeC efficiently. Consequently, this paper explains that an on-line performance monitor is designed and implemented for fast analysis and debugging of the program running on JaNeC. This on-line performance monitor is designed to minimize effects on a program to analyze, and provides various forms of graphic output, to analyze the program effectively. In addition, even after a program terminates, it provides interface with the off-line performance monitor, to analyze again.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.509-517
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• 2008

Rolling stock is the method of railway transportation. Especially, in the subway system which has short headways particularly during the rush hours, even one train's trouble on the main line might influence the whole line. Accordingly, to prevent a train trouble on the main line, high expense is used for the maintenance parts, workforce and facilities, etc. according to the preventive maintenance program. Therefore, in designing a EMU, emphasis should be put on the minimization of trouble and its extending influence on the mainline with the priority of safety and reliability. Seoul subway line 5 is the line that complements the first stage Seoul subway(lines 1,2,3 and 4) and is built deeply with many curved sections causing lots of dust. Studies were made to find out the importance of car design, selection of specifications and continuous maintenance on the basis of the analysis and countermeasure of the line 5 EMU inverter trouble case.

• Communications of Mathematical Education
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• v.38 no.2
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• pp.93-120
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• 2024

On-line education in mathematics education changed in various aspects before and after COVID-19. This study conducted a systematic literature review of 98 academic papers on on-line education published from 2017 to 2023 in the field of mathematics education before and after COVID19. In particular, this study conducted content analysis to organize on the definitions of various similar terms related to online education. In addition, this study explored research trends on year, research subject, research method, on-line education type, and research topic by the pre-COVID-19, COVID-19, and post-COVID-19 era. Also, a comparative analysis was conducted on literatures on the effects of online education. As a result, first, it was confirmed that there is a need to organize the definitions of terms similar to online education. Also, the implications of identifying the differences and hierarchies between each term can be found. Second, it was confirmed that teachers' expertise for on-line mathematics education was emphasized based on the result of the rapid increase in the number of on-line education studies on teachers since COVID-19. Third, it was confirmed that the number of studies on blended and flipped learning was high in pre-COVID-19, but decreased in the COVID-19 era. Instead, in the COVID-19 era, studies on real-time interactive classes were rapidly active, and even in the post-COVID-19 era, studies on real-time interactive classes still occupied a large proportion. Finally, it was confirmed that the effectiveness of on-line education varies depending on the research background and model. Accordingly, the need to be cautious in interpreting the results of each study on the effectiveness of on-line education was confirmed. Based on these findings, this study presented implications for future research on on-line education in mathematics education.