• Asian Pacific Journal of Cancer Prevention
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• 제17권7호
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• pp.3605-3610
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• 2016

Background: Histone acetylation in chromatin structures plays a key role in regulation of gene transcription and is strictly controlled by histone acetyltransferase (HAT) and deacetylase (HDAC) activities. HDAC deregulation has been reported in several cancers. Materials and Methods: The expression of 10 HDACs (including HDAC class I and II) was studied by quantitative reverse transcription-PCR (qRT-PCR) in a cohort of mesenchymal stem cells (MM-MSCs) from 10 multiple myeloma patients with a median age 60y. The results were compared with those obtained for normal donors. Then, a coculture system was performed between MM-MSCs and u266 cell line, in the presence or absence of sodium butyrate (NaBT), to understand the effects of HDAC inhibitors (HDACi) in MM-MSCs on multiple myeloma cases. Also, the interleukin-6 (IL-6) and vascular endothelial growth factor (VEGFA) gene expression level and apoptotic effects were investigated in MM-MSCs patients and control group following NaBT treatment. Results: The results indicated that upregulated (HDACs) and downregulated (IL6 and VEGFA) genes were differentially expressed in the MM-MSCs derived from patients with multiple myeloma and ND-MSCs from normal donors. Comparison of the MM-MSCs and ND-MSCs also showed distinct HDACs expression patterns. For the first time to our knowledge, a significant increase of apoptosis was observed in coculture with MM-MSCs treated with NaBT. Conclusions: The obtained findings elucidate a complex set of actions in MSCs in response to HDAC inhibitors, which may be responsible for anticancer effects. Also, the data support the idea that MSCs are new therapeutic targets as a potential effective strategy for MM.

• 전력전자학회논문지
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• 제19권6호
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• pp.488-493
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• 2014

This paper presents a carrier-based pulse-width modulation(PWM) method for reducing the common-mode voltage of a three-level four-leg converter. The idea of the proposed PWM method is intuitive and easy to be implemented in digital signal processor-based converter control systems. On the basis of the analysis of space-vector PWM(SVPWM) and sinusoidal PWM(SPWM) switching patterns, the fourth leg pole voltage of the three-phase converter called "f leg pole voltage" is manipulated to reduce the common-mode voltage. To synthesize f leg pole voltage for the suppression of the common-mode voltage, positive and negative pole voltage references of f leg are calculated. An offset voltage is also deduced to prevent the distortion of a, b, and c phase voltages. The feasibility of the proposed PWM method is verified by simulation and experimental results. The common-mode voltage of the proposed PWM method in peak-to-peak value is 33% in comparison with that of the conventional SVPWM method. The transition number of the common-mode voltage is also reduced to 25%.

• 한국정보처리학회논문지
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• 제7권2S호
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• pp.638-648
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• 2000

This paper introduces a new technique for block is matching motion estimation. Since the temporal correlation of the image sequence, the motion vector of a block is highly related to the motion vector of the same coordinate block in the previous image frame. If we can obtain useful and enough information from the motion vector of the same coordinate block of the previous frame, the total number of search points used to find the motion vector of the current block may be reduced significantly. Using that idea, an efficient predicted direction search algorithm (PDSA) for block matching algorithm is proposed. Based on the direction of the blocks of the two successive previous frames, if the direction of the to successive blocks is same, the first search point of the proposed PDSA is moved two pixels to the direction of the block. The searching process after moving the first search point is processed according to the fixed search patterns. Otherwise, full search is performed with search area $\pm$2. Simulation results show that PSNR values are improved up to the 3.4dB as depend on the image sequences and improved about 1.5dB on an average. Search times are reduced about 20% than the other fast search algorithms. Simulation results also show that the performance of the PDSA scheme gives better subjective picture quality than the other fast search algorithms and is closer to that of the FS(Full Search) algorithm.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제13권6호
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• pp.407-411
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• 2007

HTML은 웹 페이지의 시각적 표현을 목적으로 하고 있기 때문에, HTML로 작성된 웹 문서에 대한 색인과 질의는 쉬운 문제가 아니다. 그러나 웹 페이지를 표현하는 태그들이 가진 내재적 의미들은 검색 엔진의 성능을 향상시킬 수 있는 가능성을 가지고 있다. 본 논문은 이러한 HTML 태그의 내재적 의미를 이용하기 위해 마크업 패턴을 정의하고, 이를 웰 검색에 응용함으로서 검색 성능을 향상하고자 한다. 마크업 패턴은 웹 레이지 작성자의 표현 의도를 담고 있으며, 명시적으로 하나 이상의 HTML 태그의 연속으로 표현된다. 웹 페이지에서 마크업 패턴을 찾아내고, 이를 웹 검색에 응용하기 위해 본 논문에서는 웹 문서를 재색인하는 방법을 제안한다. 제안하는 방법을 적용한 웹 검색의 성능 향상을 증명하기 위해, BBC와 CNN 웹 사이트의 문서들을 대상으로 실험을 진행하였다. 대상 문서들은 제안한 방법을 통해 가중치를 갖게 되며, 특정 질의에 대한 정확도를 기존 검색 엔진과 비교하여, 본 논문에서 제안하는 마크업 패턴을 이용한 웹 검색의 성능 향상을 증명할 것이다.

• 한국지역사회생활과학회지
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• 제17권1호
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• pp.165-173
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• 2006

The farmers' nutritional condition can not be compared with other citizens according to the Korean National Health & Nutrition Examination Survey, and based on other literature reviews. These farmers have either less access to educational materials or have no idea and do not understand the importance of nutritional education. The purpose of this study is to develop an appropriate reading material on nutrition to educate the farmers. To do this, the first step was to gather sufficient available materials for the review of related literature. Second, a survey was conducted to assess the needs of farmers and extension workers for educational materials on nutrition. The results showed that the farmers preferred the following topics: Menu Planning or Menu for Health' (62.1%), Dietary Assessment (49.7%), Dietary Guideline for Farmers (35.7%), and Cooking Method and Recipe (32.6%). They also preferred the booklet type (62.7%). These materials basically contained literature review, lesson plan, and needs assessment. The booklets contained in detail: 1) Dietary assessment - nutritional assessment, and assessment of meal 2) Dietary guidelines for farmers - reduce salt intakes, eat calcium-rich foods, ideal body weight, reduce alcohol-drinking and smoking, tips on eating soybean, eat meat and fish, tips on eating fruits, eat shellfish and seaweeds, and tips on eating dietary fibers, and 3) Plan a meal - menu planning and sample menu by farming patterns. Finally, the text of the final material was improved by the graphic designer using Quark Express 3.3, Photoshop 6.0, Illustrator 10.0, and Painter 8.0. The booklet has 46 pages and divided into three chapters. This contains simple and affordable recipes and provides some helpful tips for dietary and changing lifestyles. This booklet is made available for farmers and other groups interested in nutrition education.

• 디자인학연구
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• 제13권1호
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• pp.187-197
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• 2000

본 논문은 최근 디자인계에 대두되고 있는 사용자 중심의 디자인을 위한 노력의 일환으로서 문화인류학의 대표적인 리서치 방법인 애쓰노그래피를 디자인 리서치에 어떻게 적용할 수 있는지에 대한 고찰과 그 구체적인 적용사례를 제시하는 논문이다. 논문은 크게 두 부분으로 구분된다. 먼저, 문헌 고찰을 통한 애쓰노그래피의 기본개념을 소개하고 제품 디자인 영역에서의 "문화"의 개념을 정의내림으로써 디자인 리서치의 내용적 프레임？을 설정하는데 필요한 지식 기반을 구축한다. 둘째로는 감성적 미래형 전자레인지 개발을 목적으로 진행한 프로젝트를 중심으로, 애쓰노그래피가 디자인 리서치에 적용된 구체적인 예를 보여준다. 이 과정은 먼저 애쓰노그래피 리서치를 실행하는 프로세스를 소개하고, 리서치를 통해 얻은 데이터를 분석결과, 그리고 이 결과의 종합을 통한 디자인 암시의 도출을 통해 애쓰노그래피 리서치의 효용성을 논의하는 것으로 구성되어 있다. 이는 구체적인 사례를 통해 향후 디자인 리서치에 애쓰노그래피의 개념을 어떻게 적용할 것인지에 대한 아이디어를 제시하고, 그 활성화를 꾀할 목적으로 진행되었다.적으로 진행되었다.

• 대한방사선기술학회지:방사선기술과학
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• 제39권4호
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• pp.631-636
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• 2016

공간 분해능을 평가하기 위해서 이제까지는 일정하게 두 물체의 간격(이중 표적)을 근접한 것부터 점점 떨어진 간격으로 만들어진 테스트 패턴이나 팬텀을 이용하였다. 이러한 방법으로 공간분해능을 평가하면 분해능은 테스트용으로 제작된 팬텀에 있는 표적 간격으로 제한된다. 본 연구는 이러한 문제를 극복하고자 1개의 단일 표적으로 공간 분해능을 간편하게 측정할 수 있는 새로운 방법을 제안하고 검증한 것이다. 이를 위해 PSF 및 JND를 이용하여 공간 분해능을 추정하는 개념을 제시하였다. 이렇게 유도된 공간 분해능 추정 이론을 검증하기 위해, 상용 팬텀을 이용하여 실험하였다. 실험으로 얻어진 디지털 영상에서 라인 픽셀 프로파일을 구하기 위해 만든 LabVIEW 프로그램을 이용하여 분석한 결과, 본 연구에서 유도한 단일 표적을 이용한 공간 분해능 추정 이론과 실험적으로 일치하는 것을 알 수 있었다. 실험 결과로 디지털 영상에서 공간분해능의 상대적 평가는 단일 표적을 가지고도 충분하다는 것을 증명할 수 있었다. 따라서 단일 표적 공간분해능 평가법을 이용하면 이제까지 사용되어 왔던 이중 표적을 이용한 공간분해능 평가의 한계를 극복할 수 있다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제35권2호
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• pp.128-136
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• 2008

한국어 구문 분석의 초기 단계로서 병렬구조의 해석은 파싱의 효율을 높일 수 있다. 본 논문은 병렬구조 해석을 위한 비지도식 언어에 독립적인 확률 모델을 제안한다. 이 모델은 병렬구조의 대칭성과 상호교환성에 근거한다. 대칭성은 같은 구조가 반복된다는 것이고, 교환성은 좌우 구성요소를 교환해도 같은 의미를 지닌다는 것이다. 병렬구조는 일반적으로 대칭성을 따르지만, 수식어의 성질에 따라서 한쪽만을 수식하는 비대칭적인 구조가 출현하기도 한다. 비대칭 병렬구조 해석을 위해서 추가적으로 수식관계 통계정보를 사용한다. 제안된 모델을 본 논문에서는 "와/과" 조사로 이루어진 한국어의 명사구 병렬구조를 해석하는데 사용되는 것[1]을 중점으로 보여준다. 지도적 방식에 의한 모델을 포함한 다른 모델들에 비해 효율적임을 실험적으로 보여준다.

• 한국과학교육학회지
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• 제14권1호
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• pp.85-102
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• 1994

The purpose of this study was to analyze students' physics problem solving processes and to find the patterns of their problem spaces when high school and university students solved the physics problems. A total of 51 students in a high school and in two universities participated in this study. Their thinking processes in solving 5 physics problems on electric circuit were recorded by using 'thinking aloud' method and were transferal into protocols. 'The protocols were analyzed by the coding system of problem solving process. One of the major theoretical contributions of the computer simulation approach to problem solving is the idea of problem space. Such a concept of problem space was applied to physics problems on electric circuit in this study, and students' protocols were analyzed by the basic problem spaces which were made up from the item analysis by the researcher. The results are as follows: 1) On the average 4.0 test items among 5 ones were solved successfully by all subjects, and all of the items were solved correctly by only 19 persons among all of them. 2) In regard to the general steps of problem solving process, there was little difference for each item between the good solvers and the poor ones. But according to the degree of difficulty of task there was a good deal of difference. For a complex problem all of 4 steps were used by most of students, but for a simple one only 3 steps except evaluating step were used by most of them. 3) It was found in this study that most of students used mainly the microscopic approach, that is, a method of applying Ohm's law on electric circuit simply and immediately, not using the properties of electric circuits. And also it was observed that most of students used the soloing tom below, that is, a solving path in which they were the first to calculate physical Quantities of circuit elements, before they caught hold of the meaning of the given problem regardless of the degree of difficulty.

• 한국과학교육학회지
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• 제17권4호
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• pp.525-540
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• 1997

The present study tested the hypothesis that maturation of the prefrontal lobes is a crucial factor determining the performance of scientific reasoning tasks, Functions of the prefrontal lobes, such as activating relevant information, sequential planning and monitoring, and inhibiting irrelevant information, are related thinking patterns with scientific reasoning. Therefore, we inferred the idea that the prefrontal lobes play an important role in scientific reasoning. To test the hypothesis. the present study investigated a prefrontal lobe patient's task solving procedures in scientific reasoning tasks and the correlation and regression analysis between a test of prefrontal lobe function and two scientific reasoning tasks, The perseverative errors in the Wisconsin Card Sorting Test(WCST) was used as a measure of the prefrontal lobe function, The Melinark Type Task and the Classroom Test of Scientific Reasoning were used as measures of scientific reasoning abilities. Ages and Group Embedded Figure Test were also used as measures of two alternative hypotheses, general maturation and field independency respectively. The prefrontal lobe patient showed a crucial deficiency in solving scientific reasoning tasks. In the tasks, the patient could not used the reasoning of If... and... then... therefore pattern. In correlation study, the perseveration errors of the WCST showed a significantly negative correlation with two scientific reasoning tasks. Multiple regression study also showed that the perseveration errors measured as a function of the prefrontal lobes have more contribution to scientific reasoning ability than contributions of alternative hypotheses. Therefore, the present study supported the hypothesis that prefrontal lobes play a crucial role in scientific reasoning ability, What function of the prefrontal lobes do play crucial role in scientific reasoning? The present study provided an explanation for the question, which inhibiting ability of the prefrontal lobes is responsible for the scientific reasoning ability, in a part at least. That is, perseverative tendency in task-solving procedures causes a deficiency of an ability to inhibit the wrong information to solve a task. The present study provided a possibility of neuropsychological approach in science education research. The present study also showed an importance of the prefrontal lobe development in the performance of scientific reasoning task.