• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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• pp.359-362
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• 2003

In PDP(Plasma Display Panel), sub-field method is used to implement gray scale. Each sub-field has different periods. And Every gray level has information of which sub-field has to be displayed. This is called sub-field mapping. There are several sub-field mapping values in some gray levels. So, it is possible to select best choice in this paper, we propose new sub field mapping method using a fuzzy inference system to select best sub-field mapping values in accordance with input image and environment temperature. In order to implement fuzzy system, we used MATLAB fuzzy inference editor.

• PNF and Movement
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• 제12권2호
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• pp.81-88
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• 2014

Purpose: The purpose of this study is to examine the needs of prior field learning and the academic achievement of field experience learning in a college. Methods: This study was performed from May 1 to October 30, and students were given questionnaire. The research questionnaire as follows: (1) to investigate the academic achievement after field experience learning, (2) to verify the needs of field experience learning. A statistical analysis was performed using SPSS 17.0 for window version. Results: The results was as follows : First, satisfaction of field learning had scored good(47.2%) in lesson goal, good(51.8%) in acquisition of knowledge and techniques, good(51.0%) in preparation of study and good(45.9%) in association. Second, curriculum of field learning had scored normal(35.5%) in prior education, good(47.4%) in composition, good(50.8%) in guidance and good(47.2%) in contents. Third, curriculum of field learning had scored good(44.6%) in duration, good(46.1%) in numbers, good(51.3%) in convenience and normal(38.1%) in means of transportation. Forth, needs of field learning had scored good(46.6%) in field learning of practicum, good(48.2%) in field learning of theory subject, 3-4 times(42.0%) in frequency of field learning and 2hours(57.3%) in a field learning hour. Conclusion: These findings suggest that college student's thinking of field experience learning is positive. Field experience learning provided that college students have directly an opportunity of gaining valuable experience to feel the field.

• 천문학회보
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• 제36권2호
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• pp.84.2-84.2
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• 2011

A numerical simulation study of the solar coronal plasma reveals that a ballooning instability can develop in the course of flux rope merging. When magnetic field lines from different flux ropes reconnect, a new field line connecting farther footpoints is generated. Since the field line length abruptly increases, the field line expands outward. If the plasma beta is low, this expansion takes place more or less evenly over the whole field line. If, on the other hand, the plasma beta is high enough somewhere in this field line, the outward expansion is not even, but is localized as in a bulging balloon. This ballooning section of the magnetic field penetrates out of the overlying field, and eventually the originally underlying field and the overlying field come to interchange their apex positions. This process may explain how a field structure that has stably been confined by an overlying field can occasionally show a localized eruptive behavior.

• 천문학회보
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• 제35권1호
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• pp.26.2-26.2
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• 2010

It has been a puzzle in solar physics how a low-lying magnetic structure such as a solar prominence surrounded by a strongly line-tied overlying field sometimes intrudes through the latter and goes into eruption. A numerical simulation study of the solar coronal plasma reveals that a ballooning instability can explain this type of eruptive process. We consider an idealized situation with two flux ropes merging. When magnetic field lines from different flux ropes reconnect, a new field line connecting farther footpoints is generated. Since the field line length abruptly increases, the field line expands outward. If the plasma beta is low, this expansion takes place more or less evenly over the whole field line. If, on the other hand, the plasma beta is high enough somewhere in this field line, the outward expansion is not even, but is localized as in a bulging balloon. This ballooning section of the magnetic field penetrates out of the overlying field, and eventually the originally underlying field and the overlying field come to interchange their apex positions. This process may explain how a field structure that has stably been confined by an overlying field can occasionally show a localized eruptive behavior.

• 한국태양에너지학회 논문집
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• 제34권5호
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• pp.33-41
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• 2014

Heliostat field in a tower type solar thermal power plant is the sun tracking mirror system which affects the overall efficiency of solar thermal power plant most significantly while consumes a large amount of energy to operate it. Thus optimal operation of it is very crucial for maximizing the energy collection and, at the same time, for minimizing the operating cost. Heliostat field operational algorithm is the logics to control the heliostat field efficiently so as to optimize the heliostat field optical efficiency and to protect the system from damage as well as to reduce the energy consumption required to operate the field. This work presents the heliostat field operational algorithm developed for the heliostat field of 200kW solar thermal power plant built in Daegu, Korea. We first review the structure of heliostat field control system proposed in the previous work to provide the conceptual framework of how the algorithm developed in this work could be implemented. Then the methodologies to operate the heliostat field properly and efficiently, by defining and explaining the various operation modes, are discussed. A simulation, showing the heat flux distribution collected by the heliostat field at the receiver, is used to show the usefulness of proposed heliostat field operational algorithm.

• 가족자원경영과 정책
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• 제13권3호
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• pp.247-280
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• 2009

The purpose of this study was to investigate the actual conditions of management of the healthy family field practicum and to present suggestions for its improvement. For this purpose, a preliminary investigation, survey, data analysis, interview as secondary source, and final data analysis were processed as research methods. The subjects of this study were the 42 supervisors in the centers which oversee the field practicum experience and the 12 supervisors in the centers which do not oversee the field practicum experience. 3 supervisors were interviewed to inquire about the reformation of field instruction in Healthy Family Support Centers. Analysis was made of the general characteristics of the above-mentioned 54 supervisors, including sex, age, academic background, certificate of qualification, class of position, and length of career related to the healthy family program. The environment of the field practice, such as the numbers of students supervised, time of field practice, practice hours, and so on, was examined in the centers which oversee the field practicum experience. The actual condition of operation investigated was divided into the preparatory stage, the early stage, the midterm stage, and the end stage. Research was conducted on the improvement of the field practicum, including the proper number of students supervised, adequate practice hours, interaction with universities or colleges, obstacles to the field practicum, and of practicum. The possibility and preparation of a further field practicum was conducted for 12 Healthy Family Support Centers, by inquiring about (a) the reasons for not overseeing the field practicum experience and (b) the needs of universities or colleges for a field practicum. The 54 supervisors surveyed suggested a particular need for improvement in human resources, the space of field instruction, system of field practicum, length of practice hours, orientation for students etc. This study investigated the actual conditions and suggested improvements of the field practicum in Healthy Family Support Centers. Therefore, its results should be meaningfully used to develop the Field Practicum for the Healthy Family and to conduct further studies.

• KIEAE Journal
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• 제5권1호
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• pp.43-49
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• 2005

People grow up and build up most of their character through living in dwelling space and have relax and refresh at home. Creating healthy dwelling space is being considered very important in architectural planning and design for providing comfortable living environment and improving quality of life. One of the properties of the earth is that the earth has a magnetic field associated with it- the Geomagnetic field. The geomagnetic field is produced by a combination of crustal rocks, external electric current systems that surround the earth that surround the earth and currents induced in the outer layers of the earth by magnetic field variations. Human beings have evolved with the background of magnetic field, they are accustomed to living in its presence. Geopathic stress occurs at geopathic zones where the geomagnetic field is disturbed. Geopathic zones exhibit magnetic charges. Geopathic zones are characterized by variations in geomagnetism, for the geomagnetic field is not uniform but exhibits many highly localized distortions, some random, some fairly regular. These occur in geological faults, caves and underground water channel. Many research papers and experiments of the western countries indicates that the geomagnetic field affects the people and living organism in dwellings. Therefore, it is necessary to investigate the geomagnetic field and people's response in living space. In this study the Health Hazard of geomagneic field in dwelling are studied through literature survey of related science field.

• 대한수학회보
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• 제55권6호
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• pp.1823-1834
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• 2018

The position vector field x is the most elementary and natural geometric object on a Euclidean submanifold M. The position vector field plays very important roles in mathematics as well as in physics. Similarly, the tangential component $x^T$ of the position vector field is the most natural vector field tangent to the Euclidean submanifold M. We simply call the vector field $x^T$ the canonical vector field of the Euclidean submanifold M. In earlier articles [4,5,9,11,12], we investigated Euclidean submanifolds whose canonical vector fields are concurrent, concircular, torse-forming, conservative or incompressible. In this article we study Euclidean submanifolds with conformal canonical vector field. In particular, we characterize such submanifolds. Several applications are also given. In the last section we present three global results on complete Euclidean submanifolds with conformal canonical vector field.

• 대한방사선치료학회지
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• 제21권1호
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• pp.17-23
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• 2009

목 적: 두경부암의 치료에 있어 상부 두경부의 양측면조사면과 하경부의 전방조사면의 접합부위에 균등한 선량을 조사하는 것은 매우 중요하다. 접합부위의 선량분포개선을 위하여 하경부 전방조사면의 치료시 Field-in-Field technique을 이용하여 부족선량(under dose)과 초과선량(over dose)으로 인한 선량불균등을 개선하고 일반치료와의 비교를 통하여 두경부암치료에 적용하고자 한다. 대상 및 방법: 상부 두경부의 양측면 조사시 빔의 확산으로 일어나는 입사점과 출사점의 선량차이를 알아보기 위하여 인체모형팬톰을 이용하였다. 인체모형팬톰을 전산화단층촬영하고 전산화치료계획에서 관심점의 선량비교를 시행하였고, 하경부 접합부위의 선량비율을 계산하여 이를 보정하였다. 조사면 접합부위의 선량분포를 알아보기 위하여 하경부의 접합부위에 저감도 필름을 놓고 일반적인 치료인 상부 두경부의 양측면조사와 하경부의 전방조사시 선량분포를 측정하였다. 또한, 상부 두경부 양측면 조사에 따른 빔의 확산을 고려한 Field-in-Field technique을 이용하여 하경부 전방조사를 할 때의 접합부위의 선량분포 차이를 측정하여 비교하였다. 접합부위의 관심점 선량을 알아보기 위하여 열형광선량계를 이용하여 인체모형팬톰내의 관심점에서의 선량변화를 비교, 분석하였다. 결 과: 전산화치료계획에서 하경부의 접합부위에 Field-in-Field technique을 적용하여 치료계획시 상부 두경부 양측면 조사와 선량합성을 한 경우 부족선량 영역의 선량이 4.7~8.65% 이상 증가하였다. 초과선량 영역의 선량도 2.75~10.45% 감소하였다. 또한, 저감도 필름을 이용한 측정에서는 부족선량영역에서 11.3% 증가, 초과선량영역에서 5.3% 감소한 것으로 나타났다. 열형광선량계를 이용한 관심점선량측정에서도 Field-in-Field technique 적용시 부족선량을 최소 7.5%에서 최대 17.6%까지 보정해주는 것으로 나타나 불균등한 선량분포를 개선할 수 있었다. 결 론: 전산화치료계획시 빔의 확산을 고려한 Field-in-Field technique을 적용하면 접합부위의 선량보정을 통해 냉점(cold spot)과 온점(hot spot)을 줄일 수 있었으며 특히, 빔의 확산에 따른 입사점의 부족선량을 보정할 수 있었다. 본 실험을 통해 Field-in-Field technique의 임상적용시 경부임파절의 저선량으로 인한 임파절전이에 대한 위험도를 감소시킬 수 있을 것으로 사료된다.

• 혜화의학회지
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• 제8권1호
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• pp.559-592
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• 1999

It has been known that Ki(氣) energy is very effective on many adult diseases. Oriental Medicine has acknowledged Ki as an existing reality and investigated its effects on the body. However, the existence of Ki has not been fully explained. In order to find a conclusive evidence on the existence of Ki, this experiment was done to study the mutual relationship of Ki with a magnetic field and BEP (biological energy projector). The BEP apparatus was irradiated under the magnetic field on rats in the hyperlipidemic induced state. Following criterias were measured in this experiment: weight change, weight of the visceral organs, serum, hepatic lipid peroxide, bleeding time, tissue factor, and etc. The following results were obtained in this study: 1. The weight of rat significantly decreased in the magnetic field treated group and radically reduced in the group treated with both magnetic field and BEP. 2. The weight of liver, heart, and kidney increased in both the magnetic field treated group and magnetic field+BEP group compared to the normal group, but decreased in comparison to the control group. No changes were witnessed in the weight of spleen. 3. Serum and hepatic total cholesterol, total lipid, and lipid peroxide level significantly decreased in both magnetic field treated group and magnetic field+BEP treated group, while lipase activity has increased noticeably. 4. Serum HDL showed a significant increase in both magnetic field treated group and magnetic field+BEP treated group compared to the control group, while LDL and VLDL level decreased significantly. 5. A bleeding time significantly increased in both magnetic field treated group and magnetic field+BEP treated group compared to the control group. A tissue factor value of the lung decreased in the magnetic field treated group and magnetic field+BEP treated groups while increased in the control group. 6. Serum and hepatic lipid peroxide and glutathione level were significantly decreased in the magnetic field treated group and magnetic field+BEP treated group, while hepatic glutathione level was significantly increased compared to the control group. 7. A significant increase was found in the serum hydroxyl radical and SOD activity in the dietary hyperlipidemic rats, and significant decrease was found in the serum lipid peroxide content and superoxidase activity. 8. Hepatic cytosolic enzyme xanthine oxidase and aldehyde oxidase showed a significant decrease in the magnetic field treated group and magnetic field+BEP treated group. Through the above experimental results, one can suggest that the magnetic field with BEP can suppress hyperlipidemia and boost lipid metabolism and restructuring a lipid in liver, which increases the function of liver. To conclude, BEP is considered to show more potent effects under the exposure of magnetic field because magnetic field seems to increase the flow of Ki in the body.