• Journal of Power Electronics
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• v.16 no.4
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• pp.1612-1620
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• 2016

This paper presents the dynamic excitation control of a siphon-turbine coupled pico-hydro powered cage rotor induction generator and load matching for off-grid electricity generation. Through the proposed dual-role of the current-controlled voltage source converter (VSC), acting as static synchronous compensator and load controller, real and reactive power are dynamically controlled in a decoupled manner with a self supported DC-bus. The proposed scheme entails minimal computation for ensuring the rated (set) capacity of real power. The scheme also exhibits fault immunity for protection, thus enabling the effective handling of constant power electrical loads presented by base telecom station towers in remote locations. The performance of the system is evaluated under MATLAB/Simulink and is experimented through a developed hardware prototype. Simulation and experimental results show close conformity and validate the effectiveness of the proposed scheme.

• Steel and Composite Structures
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• v.15 no.4
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• pp.425-438
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• 2013

A new-styrofoam-concrete composite sandwich slab with function of heat insulation is designed. Four full-scale simply supported composite sandwich slabs with different shear connectors are tested. Parameters under study are the thickness of the concrete, the height of profiled steel sheeting, the influence of shear connectors including the steel bars and self-drilling screws. Experimental results showing that four specimens mainly failed in bending failure mode; the shear connectors can limit the longitudinal slippery between the steel profiled sheeting and the concrete effectively and thus guarantee the good composite action and cooperative behavior of two materials. The ultimate sagging bending resistance can be determined based on plastic theory. This new composite sandwich slab has high sagging bending resistance and good ductility. Additionally, these test results help the design and application of this new type of composite sandwich slab.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1224-1226
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• 2003

In this work, we developed a high resolution printing technique based on transferring a pattern from a PDMS stamp to a Pd and Au substrate by microcontact printing Also, we fabricated various 2D metallic and polymeric nano patterns with the feature resolution of sub-micrometer scale by using the method of microcontact printing (${\mu}$CP) based on soft lithography. Silicon masters for the micro molding were made by e-beam lithography. Composite poly(dimethylsiloxane) (PDMS) molds were composed of a thin, hard layer supported by soft PDMS layer. From this work, it is certificated that composite PDMS mold and undercutting technique play an important role in the generation of a clear SAM nanopattern on Pd and Au substrate.

• Asia pacific journal of information systems
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• v.12 no.1
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• pp.45-65
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• 2002

Factors influencing the success or failure of information systems(IS) have been discussed in many literature. However, limited theoretical development or empirical research have examined the effectiveness of hospital information systems(HIS). This study set out the research model of influencing factors and the performance of HIS through theoretical studies based on Management Information Systems, and then empirically tested hypotheses related to the model. The model was tested using LISREL analysis on the sample of 274 respondents who have worked with the HIS. The major results of this study are as follows: First, system characteristics and organizational characteristics have a statistically significant influence on user satisfaction. Second, the hypothesis 3, proposing that computer self-efficacy would relate positively to user satisfaction, was not supported by the results, though. According to these results, system quality, information quality, service quality and support of top management are very important variables for IS success. The study's findings also indicate DeLone and McLean's model is correct in proposing that the indirect relationship between influencing factors and organizational effectiveness, mediated by user satisfaction, is an important one.

• English Language & Literature Teaching
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• v.17 no.4
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• pp.75-95
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• 2011

The purpose of this study was to evaluate a group activity, reciprocal peer tutoring (RPT), in order to investigate advantages and challenges of RPT in promoting cooperative and collaborative learning environment for EFL University reading instruction. The participants in this study were 89 students taking an English reading course at a Korean university. RPT is a learning strategy whereby learners help each other and learn by teaching. This program was supported by a Vygotskyan perspective which assumes that learners gain mastery and develop cognitive skills through social interaction with more proficient others and their environment. This study relied particularly on participant perceptions through questionnaire survey and Anonymous Online class Report of the course. This study showed various advantages for tutors such as learning through teaching and becoming more autonomous and responsible for their own learning. Non-threatening and highly motivating learning atmosphere are parts of benefits for tutees. Other advantages for tutees included improved level of academic self-confidence, and motivation. This study also revealed several drawbacks associated with the problem of inaccuracy in students' production and students' demand for more direct teacher role. (182 words).

• Journal of Korean Academy of Nursing
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• v.35 no.5
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• pp.904-913
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• 2005

Purpose: The purpose of this study was to investigate smoking cessation behavior of male taxi drivers in Korea on the basis of the Transtheoretical model(TTM), and to validate the usefulness of TTM. Method: Data were collected using a self-reported questionnaire including smoking history and major factors of TTM from 208 subjects who were current smokers or ex-smokers. Data were analyzed by descriptive statistics and ANOVA. Result: Most subjects ($85.1\%$) were current smokers. Stages of change were precontemplation ($44.7\%$) and contemplation ($27.4\%$). Subjects in precontemplation stages had the lowest mean score in processes of change and the highest mean scores in decisional balance(pros) and temptation(positive affective, habitual/craving). According to stages of change, there were statistically significant differences in processes of change, decisional balance, and temptation. Conclusion: This study supported the generalization of TTM. As this study showed that the subjects didn't have motivation in smoking cessation, applying tailored smoking cessation programs for taxi drivers is needed.

• The Korean Journal of Community Living Science
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• v.14 no.3
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• pp.3-11
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• 2003

The objectives of the study were to analyze the current conditions of the“NONGCHON ILGAM GATCI”project (an income generating project for rural areas) and to suggest possible improvements. Among the 567 business which have been supported by the project, implemented in 1990 by the Department of Rural-Home-Improvement of the Rural Development Administration, 361 (63.7%) can be categorized as being in the self-supporting stage. Another 126 (22.2%) can be said to be in the incubation stage. Data for the case study was collected from 20 project sites. The“NONGCHON ILGAM GATCI”project has been progressing successfully when compared with other rural development projects. However, there are still some problems. Among the problems are the lack of a business mindset and management abilities in individuals, and the fact that the businesses and their products are not well hewn on the market. To remedy these problems, education toward improving business and management skills, a unified public relations system, and institutional support from the government are greatly needed.

• Proceeding of KASS Symposium
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• 2005.05a
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• pp.167-172
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• 2005

In the dynamic analysis of cable structures, geometrical non-linearity due to the flexibility of cables must be considered efficiently. In this paper, formulation of tangent stiffness matrix of elastic catenary cable is derived by using relative nodal displacements, self-weight and unstressed cable length. Free vibration analysis of simply supported cable using elastic catenary cable elements is conducted and compared with that using truss elements. The result shows that elastic catenary cable elements are more compatible than truss elements in the case of analysis of cable structures. Furthermore, the characteristic of dynamic behaviors of cable structures by temporary unstability phenomenon is confirmed.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.460-466
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• 2015

The remaining features in this study using the Freecad proceeds according to the overall effect was not supported by the modeling Freecad were conducted a study to complement using the CATIA program or other commercially available. The focus of this study is that there can be obtained the stability through the center of gravity of the balancing of two parts by increasing the weight of the other magnet through a Fortuna other end of the weight of the bar, using the center of gravity. Finally, to find the optimal design of the weight and thickness of the main bar through the center of gravity balancing is the purpose of this study.

• Journal of Families and Better Life
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• v.14 no.1
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• pp.163-176
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• 1996

This study explores the overall social activities of the middle-aged women. The middle-aged married women of this study are the 40-59 years old and having youngest child above 10 years. Their social activities are categorized into work activities leisure avtivities social network with kin friends and neighbors and religious activities. The results are summarized as follows: (1) The work activities of he middle-aged married women are characterized by stable employment preparation of reentry to the job worries of unemployment and preparation of retirement(2) The leisure activities of the middle-aged married women are devided into two styles; family oriented activities and self developing activities. (3) In social networks especially the social relation with neighbor are increased and the relation with kinship tends to be bilineages. (4) Their religious activities are more supported by families than other activities. From he result this study suggests that : (1) The middle-aged m rried women might accept their midlife as a developmental stage. (2) The volunteer activities might be extended throughout the social activities (3) New social education programs for helping women's growth might be developed.