• 제목/요약/키워드: 김대성

검색결과 384건 처리시간 0.023초

SIFT 기법을 이용한 중.저해상도 위성영상간의 자동 기하보정 (Automatic Image-to-Image Registration of Middle- and Low-resolution Satellite Images Using Scale-Invariant Feature Transform Technique)

  • 한동엽;김대성;이재빈;오재홍;김용일
    • 한국측량학회지
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    • 제24권5호
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    • pp.409-416
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    • 2006
  • 영상 기하보정은 여러 가지 데이터의 조합으로부터 얻어질 수 있는 영상 분석 작업에 매우 중요한 전처리 과정 중 하나다. 본 연구는 최근 평면 영상간 기하보정에 많이 사용하고 있는 SIFT 기법을 적용하여, 다양한 해상도를 가진 위성영상의 자동 기하보정을 수행하는데 초점을 맞추고 있다. 2차원 영상의 조건을 만족하기 위해 기복변위의 영향이 상대적으로 적은 중 저해상도 위성영상의 기하보정을 수행하였으며, 다양한 해상도 영상을 조합함으로써 공간해상도의 차이를 보이는 영상의 기하보정에 SIFT 기법을 적용할 수 있는지를 실험하였다. 결과를 통해, SIFT 기법이 기존의 상관계수를 이용하여 특징점의 정합을 수행하는 방법에 비해 높은 정합률을 나타냈으며, 추출된 정합쌍을 자동 영상 기하보정에 사용할 수 있을 것으로 기대한다.

변화탐지를 위한 Hyperion 초분광 영상의 자동 기하보정과 밴드선택에 관한 연구 (A Study on Automatic Coregistration and Band Selection of Hyperion Hyperspectral Images for Change Detection)

  • 김대성;김용일;어양담
    • 한국측량학회지
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    • 제25권5호
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    • pp.383-392
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    • 2007
  • 본 연구는 초분광 영상을 이용한 변화탐지 기법의 전처리 과정 중 하나인 영상간 기하보정과 밴드선택에 초점을 맞추고 있다. 최근 그 성능이 입증된 SIFT(Scale-Invariant Feature Transform) 기법을 이용하여 자동화된 기하보정을 수행하였으며, 분광정보의 불변 특성을 반영하는 PIF(Pseudo-Invariant Feature)를 추출하여 영상의 잡음을 추정함으로써, 변화탐지를 위한 유효 밴드를 선택하였다. 또한, 기대최대화(Expectation-Maximization) 기법을 이용한 객관적인 밴드선택 방법을 구현하였다. 제안된 기법들을 실제 적용하기 위해 Hyperion 영상을 사용하였으며, 영상에 나타나는 보정되지 않은 밴드 및 Striping 잡음의 특성을 부가적으로 제거하였다. 결과를 통해, 변화탐지를 위한 최소한의 요구조건인 0.2화소 이내의 정확도(RMSE)를 만족하는 신뢰도 높은 기하보정을 수행할 수 있었으며, 시각적인 판단에 의존하던 밴드선택을 PIF를 통해 객관화할 수 있음을 확인하였다.

호흡기 증상에 대한 복합제 HAE의 완화 효과 (Relief Effect of Medicinal Herb Mixture HAE Series on Respiratory Symptoms)

  • 장보윤;김다은;한지혜;이주석;김대성;조형권;김성연
    • 생약학회지
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    • 제46권4호
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    • pp.334-341
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    • 2015
  • HAE series (HAE 01 - 06), are the mixtures of medicinal plants; Lonicerae Folium et Caulis (Lonicera japonica), Scutellariae Radix (Scutellaria baicalensis), Adenophorae Radix (Adenophora triphylla var. japonica), Polygonati Oddorati Rhizoma (Polygonatum odoratum var. pluriflorum), Platycodi Radix (Platycodon grandiflorum), Liriopis seu Ophiopogonis Tuber (Liriope platyphylla). HAE 06 showed the significant antitussive effect in HAE series. HAE 04, 05, and 06 increased the effect of expectorant measured by secretion of phenol red in rats. All tested HAE series were observed to have the anti-oxidant activity determined by the scavenging activity. HAE 01, 03 and 06 were significantly reduced the production of nitric oxide (NO) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) increased by LPS. HAE 06 was selected based on the results and done further experiments. HAE 06 inhibited the number of coughing induced by citric acid in dose dependent manner. HAE 06 effectively increased the effect of expectorant. HAE 06 exhibited anti-inflammatory effects by inhibiting the production of NO and TNF-${\alpha}$. In addition, HAE 06 significantly suppressed inducible Cyclooxygenase-2 (COX-2). Especially HAE 06 has the highest effect in alleviating the respiratory symptoms. Moreover, the enhancement antioxidant activity and reduction inflammation partly were attributed to it. HAE 06 may become the promising candidate for the treatment of respiratory symptom in the future.

녹차추출물이 인체 피지선세포주에서 지질 생성에 미치는 효과 (Effect of Green Tea Extract on Lipid Synthesis in Human Sebocyte Cell Line)

  • 박시준;전병국;김대성;이강태;문연자;이건국;우원홍
    • 동의생리병리학회지
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    • 제25권4호
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    • pp.608-613
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    • 2011
  • The aqueous Green tea comes to be used with the Oriental medicine plant, it has the numerous health benefits, including antioxidant, anti-inflammatory, and anti- carcinogenic properties. Epidermal progenitor cells give rise to multiple skin lineages: hair follicle, sebaceous gland and the overlying interfollicular epidermis. Sebocytes are the cells of the sebaceous gland, which synthesize and accumulate lipid dropolets. In order to determine the effect of Green tea on lipid production, several experiments were performed in SZ95 cells (sebocytes). We found that Green tea increased lipid droplets compared with control in a dose-dependent manner. Human sebaceous glands produce sebum, a lipid mixture of squalene, wax esters, triglycerides, cholesterol esters, and free fatty acids that is secreted onto the skin. Therefore, to investigate the effects of Green tea on intracellular lipid levels, we treated SZ95 cells with Green tea, and then examined cholesterol and triglyceride levels. After treatment of the cells with Green tea, the cholesterol and triglyceride levels of SZ95 cells were increased significantly in a dose-dependent manner.

천정기보단(天精氣保丹)의 자외선에 의한 세포 손상 억제 효과 (Protective Effect of Cheonjeongkibo-Dan UV-Induced Cellular Damage in Human Dermal Fibroblast)

  • 이강태;박시준;이정로;이광식;김대성;문연자;이건국;우원홍
    • 동의생리병리학회지
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    • 제24권6호
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    • pp.950-955
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    • 2010
  • In this study, we prepared CheonJeongKiBo-Dan(7 oriental medicinal plants, 7OMP: Astragalus Membranaceus root, Panax Ginseng root, Glycyrrhiza Glabra (licorice) root, Schizandra Chinensis fruit, Polygonatum Odoratum, Rehmannia Glutinosa root, Paeonia Albiflora root) by extracting them in one reactor and studied its efficacies on skin. UV irradiation has been suggested as a major cause of photoaging in skin. In order to investigate protective effects against UV-B induced cellular damage, 7OMP was extracted with 70% ethanol and dissolved in DMSO. The protective effect was detected by MTT assay, reactive oxygen species (ROS) generation, phosphorylation of ATR and p53 in human dermal fibroblast cell system after UV-B irradiation. 7OMP reduced UV-B-induced cellular damage in HDFs cells, and inhibited ROS generation. UV-B-induced toxicity accompanying ROS production and the resultant DNA damage are responsible for activation of ATR, p53 and Bad. In this study, 7OMP hampered phosphorylations of ATR and p53 in human dermal fibroblasts. Therefore, 7OMP may be protective against UV-induced skin photoaging.

신경전도검사의 정상치에 관한 연구 (Study on Normal Nerve Conduction Parameters)

  • 한송이;김대성;박규현
    • Annals of Clinical Neurophysiology
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    • 제1권2호
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    • pp.118-125
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    • 1999
  • Background and Aims : Nerve conduction study is invaluable in clinical neurology, especially for assessing peripheral neuropathies. Abnormal nerve conduction studies may result not only from peripheral nerve dysfunction itself, but also from other various mechanical, technical, and physiological factors such as age, sex, height and temperature. So we conducted this study to establish the our own normal values. Methods : In this study, from March. 1997 to July. 1998, 40 Korean adults among person came to Health Promotion Center over the age of 20 without any suspicion of neurological deficits were analysed to determine the effect of compound effects of several physiological factors. Results : The nerve conduction velocities of the upper extremity and proximal segments were faster than those of the lower extremity and distal segments. Physiological factors such as age, height and temperature affect the results of nerve conduction studies in multiple regression analysis. The sex difference is recognized over peroneal motor nerve. There are no sex differences in amplitude transformed into normal distribution. The significant physiological factor affecting the amplitude of nerve conduction is age, whereas height and temperature play no role. Conclusions : In multiple regression analysis, height is widespread variable for the nerve conduction velocities and temperature is important variable for lower extremities. The parametric statistical analysis cannot be applied to the amplitude of the compound muscle or nerve action potentials because of marked left shift in distribution. Sqareroot transformation of the CMAP and CNAP may be useful in normalizing the distribution. The most significant physiological factor affection the amplitude is age. Sex differences are not seen in nerve conduction study.

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PBL적용 자유탐구 기법이 과학탐구능력과 자기주도적 학습특성에 미치는 효과 (The Effects of Free Inquiry Method Based on PBL on Science Process Skill and Self-Directed Learning Characteristics)

  • 이용섭;김대성
    • 대한지구과학교육학회지
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    • 제3권3호
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    • pp.239-247
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    • 2010
  • The purpose of this study is to examine the effects of an free inquiry method based on PBL(Problem-Based Learning: PBL) to improve students science process skills and self-directed learning characteristics. To verify this research, twenty-two third-grade students were selected from Chung-ryeol Elementary School located in Busan. They have received pre-test and post-test about their abilities in their science process skills and abilities for self-directed learning characteristics. Also, their self-reflection data was analyzed. The teaching and learning PBL process is to provide the information named 'I am the expert on Earth and Moon' which is recreated by analyzing the science curriculum and characteristics of students from Lesson 3 'Earth and Moon', and to make plans for solving the information with K/NK method. Then, to solve the information is gathered and investigated using the PBL workbook. Lastly, students present their finding using the free inquiry method in a group. The post-test showed following results : first, the free inquiry method based on PBL stimulates inquisitiveness in students about science learning and the research group shows improved science process skill. It shows us that using the free inquiry method based on PBL can be used effects to elevate science process skill. Second, the free inquiry method based on PBL has a positive effect on self-directed learning. The research tells us that using the free inquiry method based on PBL can improve a student self-directed learning characteristics.

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실리카-PMMA 나노 하이브리드 코팅액 제조 및 특성에 관한 연구 (Studies on the Synthesis and Characteristic of Silica-PMMA Nano Hybrid Material)

  • 손대희;김대성;이성호;김송혁;이근대;박성수
    • 공업화학
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    • 제23권1호
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    • pp.53-58
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    • 2012
  • 투명한 플라스틱 필름의 표면경도를 향상시키기 위하여 유-무기 하이브리드 코팅 용액을 졸-겔 공정을 이용하여 합성하였다. 무기성분으로 콜로이드 실리카와 유기성분으로 PMMA, 유-무기 성분 간의 결합력을 향상시켜 하이브리드 코팅 층의 특성을 더욱 향상시키기 위하여 실란커플링제로서 vinyl trimethoxy silane (VTMS)과 [3-(metha cryloyloxy)] propyl trimethoxy silane (MAPTMS)를 이용하였고, 알콕시 실란의 종류, 콜로이드 실리카/PMMA의 함량비 등의 반응조건에 따라 콜로이드 실리카/PMMA 졸을 합성하였다. 이러한 졸을 PET 필름에 바코팅시키고, 열경화 시켜 하드코팅막을 제조하여 물리적 화학적 특성을 조사하였다. PMMA에 비해서 하이브리드 형태에서 코팅 막의 연필경도와 기재와의 부착력이 우수하였다.

미래문제해결 프로그램이 창의성과 과학적 태도에 미치는 효과 (Effects of Future Problem Solving Program on Creativity and Scientific Attitude)

  • 김대성;이용섭
    • 대한지구과학교육학회지
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    • 제5권1호
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    • pp.51-59
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    • 2012
  • The purpose of this study was to examine the effects of Future Problem Solving Program on creativity and scientific attitude. For this study the 4 grade, 2 class was divided into a research group and a comparative group. The class was pre-tested in order to ensure the same standard. The research group had the science class with FPSP, and the comparative group had the class with teacher centered lectures for 9 classes in 10 weeks. The FPSP was focused on finding problems, finding key problems, creating solutions, selecting the standard of judgement, making alternative solutions, and learning creative steps of solutions consisting of development of action planning. To prove the effects of this study, creativity was split up according to fluency, originality, abstractness, accuracy, and openness. Also, scientific attitude consisted of honesty, patience, curiosity, preparedness, autonomy, criticism, and openness. The results of this study are as follows. First, the science class with FPSP with finding problems, finding key problems, and creating solutions had the effect of developing the scientific creativity; fluency, originality, abstractness of the title, accuracy, and openness. Second, the FPSP had the effect of developing the scientific attitude. Students made ideas and solved the problems through divergent thinking and convergent thinking. During the class it had the effect of developing the scientific attitude; honesty, patience, curiosity, preparedness, autonomy, criticism, and openness. As a result, the elementary science class with FPSP had the effects of developing scientific creativity and scientific attitude. It means the science class with FPSP has potential possibilities and value to develop scientific creativity and scientific attitude.

흡입독성평가를 위한 비부노출 챔버의 유동흐름 특성 (Characteristics of flow field of nose-only exposure chamber for inhalation toxicity evaluation)

  • 노학재;봉춘근;봉하경;김용구;조명행;김상화;김대성
    • 한국입자에어로졸학회지
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    • 제12권1호
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    • pp.1-9
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    • 2016
  • In this work, we evaluated the characteristics of flow field and uniformity of the nose-only exposure chambers for the inhalation toxicity test. Computational fluid dynamics (CFD) modeling was carried out to demonstrate uniformity of the nose-only exposure chambers. Because it is very important in the inhalation toxicity experiments that test materials are distributed uniformly to each holder of the chamber. The test was done with these 3 types of chamber with different form to develop inhalation toxicity evaluation system, easy-to-operate system among exposure chamber used for evaluating inhalation toxicity of environmental chemical mixtures. Through CFD interpretation, nose-only exposure chamber was made with the selection of the optimal conditions. For its evaluation, one type of fragrance was selected and measured particle size distribution of each port. The gene becoming luminous to green fluorescence was combined with GPT-SPE, a type of tGFP vector, to be inhaled to the mouse. Based on this, luminous intensity was checked. As a result, total particle number concentration of each port had average value of $3.17{\times}10^6{\sharp}/cm^3$ and range of the highest and lowest concentration value was approximately ${\pm}4.8%$. Autopsy of lung tissues of mouse showed that it had clearly better delivery of gene compared to the control group.