• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.825-829
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• 2005

This paper presents an approach for designing a fuzzy logic-based adaptive SVC damping In controller for damping low frequency power oscillations. Power systems are often subject to low Frequency electro-mechanical oscillations resulting from electrical disturbances. Generally, power system stabilizers are designed to provide damping against this kind of oscillations. Another means to achieve damping is to design supplementary damping controllers that are equipped with SVC. Various approaches are available for designing such controllers, many of which are based on the concepts of damping torque and others which treat the damping controller design as a generic control problem and apply various control theories on it. In our proposed approach, linear optimal controllers are designed and then a fuzzy logic tuning mechanism is constructed to generate a single control signal. The controller uses the system operating condition and a fuzzy logic signal tuner to blend the control signals generated by two linear controllers, which are designed using an optimal control method. First, we design damping controllers for the two extreme conditions; the control action for intermediate conditions is determined by the fuzzy logic tuner. The more the operating condition belongs to one of the two fuzzy sets, the stronger the contribution of the control signal from that set in the output signal. Simulation studies done on a one-machine infinite-bus and a four-machine two-area test system, show that the proposed fuzzy adaptive damping SVC controller effectively enhances the damping of low frequency oscillations.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1445-1456
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• 2011

This paper presents the research of Low Pass Filter(hereinafter called "LPF") which is the part of Chopper Gate Control Unit on the electric rolling stock. Chopper Gate Control Unit controling the propulsive equipments of electric rolling stock consists of several electronic parts, PCB, Power Supply, Gate Circuit Amp, Freon Cooling Device, and has been used the parts made by japan manufacturer Mitsubish. But these parts recently have been more broken down and slow down performance because of long-term use, deterioration. Most of the malfunctions are low performance of LPF. Furthermore, it is physically impossible to repair LPF. Because it is molding type part and no longer manufactured. Also it needs high cost for custom-building. Therefore, it is now making up for through self-developed LPF and operating on Busan metro 1st after on-board testing. This research performed the PS Pice simulation testing, analysis of self-developed LPF performance and the wave form characteristic by multi-function synthesizer, spectrum analyzer, oscilloscope.

• Research in Community and Public Health Nursing
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• v.21 no.2
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• pp.200-209
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• 2010

Purpose: This study was conducted to determine the effects of a fall prevention program on knowledge, efficacy, and prevention behavior of falls among the low-income elderly. Methods: This study used a nonequivalent control group pre and post test quasi-experimental research design. The study was conducted from August to October, 2008 with 20 subjects in the experimental group and 22 in the control group who were registered at the public health center of S District in D City. Results: Hypothesis 1 "The experimental group that participated in the fall prevention program will show a higher degree of knowledge about falls than the control group" was supported. Hypothesis 2 "The experimental group will have a higher degree of self-efficacy of falls than the control group" was not supported. Hypothesis 3 "The experimental group will report fall prevention behavior more frequently than the control group" was supported. Conclusion: It was verified that the fall prevention program in this study was an effective intervention to improve knowledge about falls and fall prevention behaviors among the low-income elderly. The results can be used as part of an intervention to prevent falls for the vulnerable elderly such as the low-income elderly.

• The Korean Journal of Community Living Science
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• v.17 no.2
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• pp.89-103
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• 2006

This study was performed to provide sources of nutrition education for female adolescents by identifying eating disorder patterns and their relationships with self-body image, weight control, and eating behavior. A total of 329 female middle school students were recruited and completed a general characteristics survey, the Eating Attitudes Test(EAT-26), a perception of self-body image survey, a concern for weight control survey, an eating behavior survey, and the Mini Dietary Assessment Index(MDA). Eating disorder patterns were identified to be obesity stress and weight control(OW), risk of binge eating(RB), and dietary restraint(DR) by factor analysis. OW pattern was related with stout body shape, body dissatisfaction, experience of weight control, skipping of dinner, and low MDA score. RB pattern was associated with lean body shape, body satisfaction, indiscreet snack behavior, and the eating time of snacks. The DR pattern was associated with normal body shape, regular meal times, desirable snack behavior, and high MDA scores. The results indicated that the eating patterns of adolescent were not identical to existing diagnostic categories. Furthermore, each eating pattern displayed different characteristics of perception on self-body image, concern for weight control, and eating behavior. In conclusion, nutrition education for female middle school students could reflect the different characteristics of each eating disorder pattern.

• Korean Journal of Child Studies
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• v.31 no.2
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• pp.17-34
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• 2010

This study was aimed to at examining whether the effects of cooperative learning on children's social competence and self-esteem would be different in terms of young children's intellectual ability. To this end, a total of 64 five-year-old children attending two kindergartens in Kyunggi-Do were selected to participated in this study. Each child was tested on the short form of K-WPPSI and fell into one of two levels (high or low). The children in the experimental group took part in thirty-five 30~40 minute sessions of cooperative learning, while the control group engaged in individual learning. The results were as follows : First, children who participated in cooperative learning achieved higher improvements in social competence and self-esteem than children engaged solely in individual learning. Second, there were no any significant differences in improvement in terms of social competence and self-esteem between the high and the low intelligence levels. On the basis of these results, it could be concluded that cooperative learning had a number positive effects upon the levels of young children's social competence and self-esteem.

• Korean Institute of Interior Design Journal
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• v.23 no.4
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• pp.140-148
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• 2014

The objective of this study is to address Effective Learning Methodology by subjects to acquire National Certification which is an essential requirement to get employed. For this purpose, analysis was completed after conducting a survey on the class to obtain Interior Architecture Engineer Certification. 23 applicants were selected based on effectiveness of each subject, level of difficulty, degree of understanding, mentoring effect, self-driven learning, and group discussion. Results are as below. Upon the first written test, Interior Design Theory and Chromatics showed a high learning effectiveness in self-driven learning and mentoring. Ergonomics showed a high learning effectiveness in mentoring, self-driven learning and group discussion while Building Materials, Architecture Construction presented a high effectiveness only in mentoring and group discussion. Architecture Environment showed average learning effectiveness in mentoring and group discussion and showed a low effectiveness in self-driven learning. Upon the second practice test, Interior Architecture Construction and Planning/Management of Construction Materials presented an average learning effectiveness in mentoring and group discussion. Process Control and Adding Up(Supply Calculation) showed a low learning effectiveness in self-driven learning and presented an average to below average learning effectiveness in mentoring and group discussion. Lastly, Interior Design Plan, Interior Design Drawings presented average learning effectiveness in mentoring and group discussion however they showed a high effectiveness in self-driven learning.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.22 no.4
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• pp.294-301
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• 2011

Objectives : This study investigated factors related to suicide in high school students and focused on perceived academic performance. Methods : We surveyed 293 grade 10 high-school students in Jeju and Gyeonggi provinces and gave them self-assessment questionnaires. To evaluate the suicide risk, the questionnaire included questions about suicidal thoughts, plans, threats, deliberate self-injury, and suicide attempts from the Scale for Suicide Ideation (SSI). Also, it included the Beck Depression Inventory (BDI), Beck Hopelessness Scale (BHS), Locus of Control Scale (LOC), Rosenberg's Self Esteem Scale (RSE) and Perceived Academic Performance (PAP) to identify factors related to suicide in high school students. Results : Depression, hopelessness, and low self-esteem were related with suicidal thoughts, plans, attempts, and severe suicidal ideation (SSI score${geq}$16). In the multivariate analysis, a low level of PAP (OR=3.796, 95%CI 1.280-11.257) was significantly associated with severe suicidal ideation (SSI score${geq}$16). Deliberate self-injury was most prevalent in failing the PAP group and also having a high level of PAP (OR=6.161, 95%CI 1.474-25.760). Conclusion : The authors found that the suicide risk of high school students is related to depression, hopelessness, low self-esteem and a low level of PAP. These results provide significant indicators in planning an adolescent suicide prevention program.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.327-339
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• 2003

In this paper, a self-organizing fuzzy controller(SOFC) for the industrial robot manipulator with a actuator located at the base is studied A fuzzy login composed of linguistic conditional statements is employed by defining the relations of input-output variable of the controller, In the synthesis of a FLC, one of the most difficult problems is the determination of linguistic control rules from the human operators. To overcome this difficult SOFC is proposed for a hierarchical control structure consisting of basic level and high level that modify control rules. The proposed SOFC scheme is simple in structure, fast in computations and suitable for implementation of real-time control. Performance of the SOFC is illustrated by simulation and experimental results for robot with low joints.

• Science of Emotion and Sensibility
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• v.26 no.4
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• pp.29-40
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• 2023

Anxiety is known to upset the balance of the attentional system and prioritize the stimulus-driven system over the goal-directed system; however, self-instruction induces goal-directed behavior with the self-regulation effect. This study verified the effects of meteorological and self-instruction conditions on pilot anxiety and flight task performance for in-service pilots in a virtual reality environment. The meteorological conditions were divided into visual meteorological and very low visibility conditions, and the flight tasks were conducted by varying whether or not self-instruction was performed. The experiment results reveal that anxiety and heart rate were higher, and the performance of the flight task was lower in the very low visibility condition. However, anxiety and heart rate were lower, and the performance of the flight task was higher in the self-instruction condition. This result suggests that accidents due to difficulty in flight may increase because of anxiety, but such accidents may decrease because of flight performance improvement by self-instruction.

• Clinical and Experimental Pediatrics
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• v.54 no.2
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• pp.45-50
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• 2011

Compared to that in the Caucasian population, type 1 diabetes mellitus (T1DM) incidence rates are very low in Koreans. Therefore, compared to the recent development of pharmacological therapy applicable to Korean children with T1DM, interest in nonpharmacological therapy and psychosocial support systems remains low, as is the development of Korean-style T1DM education programs for therapeutic application. Children who have been newly diagnosed with diabetes are placed in completely new environments for treatment. For appropriate control of diabetes, patients have to self-monitor blood glucose levels and inject insulin several times a day and must use extreme self-control when they eat foods to avoid increases in blood glucose levels. Blood glucose excursions resulting from impaired pancreatic ${\beta}$ cell functions cause mental stress due to vague fears of chronic complications of diabetes. In addition, children with diabetes cannot be excluded from the substantial amount of studies required of Korean adolescents, and the absolute shortage of time for ideal control of diabetes adds to their mental stress. Many of these patients are psychologically isolated in school where they spend most of their time, and they are not appropriately considered or supported with respect to blood glucose control in many cases. In this respect, this author will introduce some of the newest views on nonpharmacological therapy and psychosocial support systems that account for important parts of T1DM management and seek measures to apply them in conformity with the social characteristics of Korea.