• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.5
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• pp.405-412
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• 1999

Meta! Halide Discharge(]\1HD) Iamps have good color rendition, long life and good focusing capability but h have flickers bv acoustic resonances. We have designed the electronic ballast for reducing acoustic resonances in high pressure discharge tube. The ballast consists of main two parts, the first part is a half-bridge inverter to make a square wave form a and the st'Cond part is a flyback converter to combine the low frequency and high frequency component. As a r result of this study, we conclude that MHD lamps of 70 watt 따c very well light(D without acoustic resonance p phenomena by the elestronic ballast.

• 대한예방의학회:학술대회논문집
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• 1996.10a
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• pp.3-26
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• 1996

Epidemiology and preventive medicine are changing together with Population and health and with ever expanding medical and non medical technologies. New technologies make epidemiology methodologically more sophisticated, but such advances risk overshadowing epidemiology's most important role: raising questions, providing answers, and helping the medical decision-making at ail levels of prevention. Epidemiology also plays a major role in the evaluation of new and other technologies whose effectiveness is poorly known. Epidemiological approaches, methods, techniques, and interpretations are widely used in new and rapidly expanding fields of medicine: research evaluation and synthesis (meta-analysis), establishment of guidelines for clinical preventive practices, new medical technology assessment, guidelines for national and international health policies, evidence-based medicine, outcomes research and disease management ('population-based' medicine and quality of care improvement). In the nearest future, infectious and noninfectious diseases may cease to be almost the sole subjects of epidemiology and they may share their place with other mass phenomena of the next millennium, such as medical practices and care, or political, social and economic actions and their consequences. Not only will primary, secondary, and tertiary Prevention will remain in the epidemiological mainstream, but health protection and health promotion will require perhaps a redefinition of epidemiology in these domains. Epidemiology and preventive medicine are both subjects of medical ethics and dilemma for right choices.

• Journal of Educational Research in Mathematics
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• v.26 no.2
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• pp.173-188
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• 2016

Research on didactic transposition in mathematics education has about 25-year and about 35-year long history in and out of Korea, respectively. This study attempts to investigate in trends of those research and to suggest tasks needed to be tackled. Major findings are followed. First, studies done in Korea tended to focus on the application of the didactic transposition theory for proving its effectiveness in understanding mathematics textbooks and mathematics lessons in-depth. It is suggested to conduct meta-analysis of the accumulated results or analysis of further applications of the didactic transposition theory to improve theoretical aspects of didactic transposition. Second, new categories for extreme teaching phenomenon were found and new typology in knowledge to be considered in the didactic transposition was developed in a few studies done in other subject matter education. Application of these to mathematics education may enhance research in didactic transposition of mathematical knowledge. Third, praxeology or a complex of praxeology for Korean school mathematics should be explored as did in other countries. Fourth, there have been rich attempts to link perspectives in didactic transposition to other perspectives or fields such as anthropology, human and education in technology era, praxeology theory in economics, epistemology in other countries but not in Korea. It is suggested to extend the scope of discussion on didactic transposition and to relate various concepts given in other disciplines. Fifth, clarification or negotiation of meaning for the main terms used in the discussion on didactic transposition such as personalization, contextualization, depersonalization, decontextualization, Topaze Effect, Meta-Cognitive Shift is suggested by comparing researchers' various descriptions or uses of the terms.

• The Journal of the Convergence on Culture Technology
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• v.4 no.3
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• pp.113-125
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• 2018

In recent years, new media art is developing to play its roles as a means of remediation to overturn, reuse, and alter the old technologies rather than technology-dependent art to accept new technologies and use them as artistic tools. Here, the concept of new should mean looking at the old technologies in an indirect way and finding new meanings in them rather than presenting new technologies. The starting point of this study was the concept of spatialization in which the concept of new media art would externalize games from inside to outside the screen in gamification-applied spaces. Participatory new media art adds a platform for viewer's participation and utilizes the entire space of the exhibition hall instead of allowing for simple viewing at the exhibition hall. The study focused on the changes and phenomena in the process of games belonging to the artistic space through the interactivity of gamification. Here, the premise was that gamification meant the "spatialization of games." The study examined several cases of games being altered in the spatialization process to figure out interactivity for viewers and developmental directions for interface design at a gallery.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.29-37
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• 2020

In the past, meta-heuristic optimization algorithms were developed to solve the problems caused by complex nonlinearities occurring in natural phenomena, and various studies have been conducted to examine the applicability of the developed algorithms. The self-adaptive vision correction algorithm (SAVCA) showed excellent performance in mathematics problems, but it did not apply to complex engineering problems. Therefore, it is necessary to review the application process of the SAVCA. The SAVCA, which was recently developed and showed excellent performance, was applied to the advanced Muskingum flood routing model (ANLMM-L) to examine the application and application process. First, initial solutions were generated by the SAVCA, and the fitness was then calculated by ANLMM-L. The new value selected by a local and global search was put into the SAVCA. A new solution was generated, and ANLMM-L was applied again to calculate the fitness. The final calculation was conducted by comparing and improving the results of the new solution and existing solutions. The sum of squares (SSQ) was used to calculate the error between the observed and calculated runoff, and the applied results were compared with the current models. SAVCA, which showed excellent performance in the Muskingum flood routing model, is expected to show excellent performance in a range of engineering problems.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.4
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• pp.527-531
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• 2012

In this paper, a novel DPSO-QI (Distributed PSO with quantum-infusion mechanism) algorithm improving one of the fatal defect, the so-called premature convergence, that degrades the performance of the conventional PSO algorithms is proposed. The proposed scheme has the following two distinguished features. First, a concept of neighborhood of each particle is introduced, which divides the whole swarm into several small groups with an appropriate size. Such a strategy restricts the information exchange between particles to be done only in each small group. It thus results in the improvement of particles' diversity and further minimization of a probability of occurring the premature convergence phenomena. Second, a quantum-infusion (QI) mechanism based on the quantum mechanics is introduced to generate a meaningful offspring in each small group. This offspring in our PSO mechanism improves the ability to explore a wider area precisely compared to the conventional one, so that the degree of precision of the algorithm is improved. Finally, some numerical results are compared with those of the conventional researches, which clearly demonstrates the effectiveness and reliability of the proposed DPSO-QI algorithm.

• Journal of The Korean Association For Science Education
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• v.36 no.1
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• pp.15-28
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• 2016

The purpose of this study is to investigate the changes of students' modeling ability in terms of 'meta-modeling knowledge' and 'modeling practice' through co-construction of scientific model. Co-construction of scientific model instructions about astronomy were given to 41 middle-school students. The students were given a before and after instruction modeling ability tests. The results show that students' 'meta-modeling knowledge' has changed into a more scientifically advanced thinking about models and modeling after the instruction. Students were able to be aware that 'they could express their thoughts using models', 'many models could be used to explain a single phenomena' and 'scientific models may change' through co-construction modeling process. The change in the 'modeling practice' of the students was divided into four cases (the level improving, the level lowering, the high-level maintaining, the low-level maintaining) depending on the change of pre-posttest levels. The modeling practice level of most students has improved through the instruction. These changes were influenced by co-construction process that provides opportunities to compete and compare their models to other models. Meanwhile, the modeling practice level of few students has lowered or maintained low level. Science score of these students at school was relatively high and they thought that the goal of learning is to get a higher score in exams by finding the correct answer. This means that students who were kept well under traditional instruction may feel harder to adapt to co-construction of scientific model instruction, which focuses more on the process of constructing knowledge based on evidences.

• The Journal of Korean Academic Society of Nursing Education
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• v.15 no.1
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• pp.32-43
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• 2009

Purpose: The purpose of this study was to identify the trend of nursing research by analyzing the doctoral dissertations in one college of nursing in Korea. Method: The areas of research, the methodological characteristics, and theories used in the research were explored in all doctoral dissertations (n=120) published from 1989 to 2006. Result: Mainly "Nursing" has been studied (44.9%) among four meta-paradigms of nursing science. The "client" domain (46.7%) and the "practice" domain (41.7%) were most frequently studied in type of nursing knowledge. The main purpose of the thesis was to develop nursing interventions and examine the effectiveness of the practice (40.8%) in quantitative research. Almost all (94.7%) of the qualitative dissertation studies were to explore phenomena in the nursing field. Almost half of the dissertations (43.9%) were an experimental design, 34.7% were a model construction, and 15.8% were a qualitative design. The majority of dissertations (83.3%) were to apply the specific theory and almost half (43.8%) studied borrowed theories from other fields. Conclusion: It is necessary to develop more rigorous and various research designs such a longitudinal design, or randomized controlled trial and this will lead to expanding the body of nursing knowledge.

• Journal of the Korean Chemical Society
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• v.64 no.5
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• pp.277-290
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• 2020

In this study, four gifted students in the second year of middle school at Gifted Education Center of the National University in Jeollanam-do were surveyed students' perceptions of the effectiveness of science class using science writing heuristic in terms of metacognition and the goals of the 2015 revised science curriculum. Through questionnaires and interviews with gifted science students, science gifted students recognized that the science class using science writing heuristic had a positive effect on the four subdomains (planning, monitoring, control, and evaluation) of metacognition. For this reason, the science gifted students presented self-directed experience in designing experiments, continually checking the collected experimental data, feedback process, and reflecting experience in preparing conclusions. Science gifted students recognized that science class using science writing heuristic had a positive effect on the goals of the 2015 revised science curriculum(attitudes, inquiry, knowledge, Science·Technology·Society(STS), and the enjoyment and usefulness of science learning) that correspond to through inquiry science writing lessons. For this reason, the science gifted students presented self-directed inquiry experiences, continual inquiry experiences on the same subject, thinking process at each stage of inquiry, learning experiences through inquiry, experience of the whole inquiry process, and inquiry of phenomena closely related to real life. Therefore, for the effective science class, it is necessary to apply the characteristics of science class using science writing heuristic which is responded by science gifted students to general science class as well as science gifted class later.

• Journal of the Daesoon Academy of Sciences
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• v.24_1
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• pp.315-349
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• 2014

This paper was carried out to bring the researches on Cultivation Practice of Daesoonjinrihoe which have been at a standstill after analyzing the directions of studies on Cultivation Practice and diagnosing its problems, in addition to that, the paper was also conducted in a way of discussing the research directions in the future. This work enables scholars who have interests in Daesoon Thoughts to easily comprehend over the length and breadth of Cultivation Practice of Daesoonjinrihoe as well as help them understand what level of researches regarding Cultivation Practice has been demanded. Furthermore, this paper will be a step-stone for scholars to ponder how and on what perspective they approach a wide variety of studies on Daesoon Thoughts. The problems reflected on the previous researches on Cultivation Practice are summarized as follows: first, except a few researches in general, problem recognition, research target, style, method, and content are not diverged from the frame defined by Jang Byeong-Gil, who set it up in Daesoon Religion and Thought (Daesoon Jonggyo Sasang) in 1989. Proliferating overlapped researches without developing problem awareness is of great concern. And such researching climate has gradually set in. Secondly, there are numerous researches intending to reveal the researcher's forceful attitude implying faith. Thirdly, most of the previous researches neglect to focus on defining the range of researches. Fourthly, when defining concepts, more thorough insight is needed. Lastly, the researches on analysing symbols and attempting signification analysis are relatively few, only to find many errors. To solve these problems, this paper suggests to develop theories which back up Cultivation Practice by researching on the fields of theory of mind-nature(心性), theory of mind-qi(心氣), theory of pain, Religious Ethics, viewpoint of God/gods, and psychology. Secondly, all the symbols and meanings of elements shown in Cultivation Practice need analyzing more elaborately sophisticatedly and more in-depth. In order to fulfil this goal, by adapting the recent trends of historical studies, it is essential to attempt to engraft Cultivation Practice of Daesoonjinrihoe on cultural phenomena, to analyze thick layers of meanings beneath its surface, to interpret differently, utilizing various perspectives such as focusing on the gender problems, and to extract true meanings out of Cultivation Practice by analyzing everyday events which can occur in real cultivation practices. Thirdly, the terms and concepts regarding Cultivation Practice base the principle themselves. Fourthly, by utilizing methodology of comparative studies on religions, the comparative researches on cultivation practice of different religious traditions are also needed. Lastly, the history of aspects on Cultivation Practice such as transition of mantras, processes which have been conducted through proprieties of prayer and training should be collected and classified. In this context, this work is very important since it helps understand the aspects of transition of originality and characteristics in Cultivation Practice of Daesoonjinrihoe according to passage of time.