• Title/Summary/Keyword: Image Transformation

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무릎 연골 두께 아틀라스를 통한 손상 평가 기법 (Knee Cartilage Defect Assessment using Cartilage Thickness Atlas)

  • 이용우;;안천수;신지태
    • 대한의용생체공학회:의공학회지
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    • 제36권2호
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    • pp.43-47
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    • 2015
  • Osteoarthritis is the most common chronic joint disease in the world. With its progression, cartilage thickness tends to diminish, which causes severe pain to human being. One way to examine the stage of osteoarthritis is to measure the cartilage thickness. When it comes to inter-subject study, however, it is not easy task to compare cartilage thickness since every human being has different cartilage structure. In this paper, we propose a method to assess cartilage defect using MRI inter-subject thickness comparison. First, we used manual segmentation method to build accurate atlas images and each segmented image was labeled as articular surface and bone-cartilage interface in order to measure the thickness. Secondly, each point in the bone-cartilage interface was assigned the measured thickness so that the thickness does not change after registration. We used affine transformation and SyGN to get deformation fields which were then applied to thickness images to have cartilage thickness atlas. In this way, it is possible to investigate pixel-by-pixel thickness comparison. Lastly, the atlas images were made according to their osteoarthritis grade which indicates the degree of its progression. The result atlas images were compared using the analysis of variance in order to verify the validity of our method. The result shows that a significant difference is existed among them with p < 0.001.

배구 레프트 스파이크와 라이트 스파이크 동작에 대한 운동역학적 변인 비교 분석 (Analysis of Sports Biomechanical Variable on the Motions of Left and Right Spikes of Volleyball)

  • 조주행;주명덕
    • 한국운동역학회지
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    • 제16권4호
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    • pp.125-134
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    • 2006
  • The purpose of this study was to analyze the Biomechanical elements by looking at the differences on the motions of the right and left spikes of right-handed offense volleyball players, using 3D image analysis and force platform. For that purpose, spike motions of six male university volleyball players were recorded three times each using two 16mm high speed cameras and the speed of recording was set at 60 frames/sec. The coordinated raw data was leveled as 6Hz using low pass filtering method and the calculation of 3D coordinates was done by using a DLT (Direct Linear Transformation) method. Also KWON 3D program was used to analyze the variables. Through the experiments and research, the following results were found: That is, in case of the right spike, the required time from the toss to the impact, which affected the success rate of offense showed as longer and on the take-off, the exact timing to touch the ball was longer because the pace between right and left feet was wider, and also after the jump, the distance between the feet indicated shorter, than the left. In addition, the degree of somersault and horizontal adduction of shoulder joint was smaller and the degree of medial rotation of shoulder joint showed bigger than the left, so it indicated that it was not centered on the body, but by the arm with an axis of shoulder using a swing motion. After the impact, the speed of the ball indicated slower compared to the left spike.

패치 CEGI를 이용한 메쉬 워터마킹 (A Mesh Watermarking Using Patch CEGI)

  • 이석환;권기룡
    • 전자공학회논문지CI
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    • 제42권1호
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    • pp.67-78
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    • 2005
  • 본 논문에서는 복소 가우시안 영상 (Complex Extended Gaussian Image, CEGI)을 이용한 3D 메쉬 모델의 블라인드 워터마킹을 제안하였다. CEGI는 메쉬의 법선 벡터 분포를 나타내는 3차원 방향 히스토그램으로, 이는 메쉬의 면적 및 임의의 기준점에 대한 거리로 표현되는 복소 가중치의 합으로 구현된다. 제안한 방법에서는 먼저 3D 메쉬 모델을 모델의 형상에 따라 여러개의 패치로 분할한다. 그리고 워터마크를 삽입하기 위하여 각 패치별로 CEGI를 구한 후에 복소 가중치의 크기가 큰 셀을 선택하여, 각 패치 CEGI 상에 통일한 순위의 셀들에 각각 삽입한다. 그리고 패치의 중점 좌표 및 셀 순위표를 이용하여 원 메쉬 모델없이 워터마크를 추출한다. 이 때, 회전과 같은 아핀 변환된 모델에서는 오일러 각을 이용한 재배열 과정을 수행한다. 실험 결과에서 제안한 방법이 절단, 아핀 변환, 및 랜덤 잡음 첨가등의 기하학적 공격 및 메쉬 간단화 등의 위상학적 공격에 견고하였으며 또한 워터마크의 비가시성을 확인하였다.

음릉천(陰陵泉)(Sp9)의 전침자극(電鍼刺戟)이 functional MRI상 뇌활성(腦活性) 변화(變化)에 미치는 영향(影響) (A fMRI study on the cerebral activity induced by Electro-acupuncture on Sp9(Yinlingquan))

  • 김정호;이현;임윤경;홍권의;이병렬;김연진
    • Journal of Acupuncture Research
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    • 제20권4호
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    • pp.114-133
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    • 2003
  • Objective : The meridian theory in oriental medicine explains that Sp9(Yinlingquan) has been considered very important for gynecological disorders, spleen and stomach disorders, and water metabolic disorders. Functional MRI is the best method of showing the evidences of the effect of the Electro-acupuncture treatment through scientific methods. On this supposition, Electro-acupuncture stimulation on Sp9(Yinlingquan) was carried out on six healthy volunteers, using the gradient echo sequence with the 3.0T whole-body MRI system(ISOL). Methods : Electro-acupuncture stimulation on Sp9(Yinlingquan), the experiment was carried out on six healthy volunteers, using the gradient echo sequence with the 3.0T whole-body MRI system(ISOL). After the needle insertion on right Sp9(Yinlingquan), 2Hz of electric stimulation was given for 30 seconds, repeated five times, with 30 seconds' intervals. The Image analysis including motion correction, talairach transformation, and smoothing was done using SPM99. Results : The electro-acupuncture stimulation on Sp9(Yinlingquan) activates Brodmann Area 13, 19, 22, 39, 40, 47 which may be the central pathways of the electro-acupuncture stimulation on Sp9(Yinlingquan). We also hypothesize that those brain areas may be directly or indirectly related with the mechanism of the effect of electro-acupuncture stimulation on Sp9(Yinlingquan).

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복류(復溜)(K7) 전침자극(電鍼刺戟)이 functional MRI상 뇌기능(腦機能) 변화(變化)에 미치는 영향(影響) (A fMRI study on the cerebral activity induced by Electro-acupuncture on K7(Fuliu))

  • 강재희;이현;이병렬;홍권의;임윤경;김연진
    • Journal of Acupuncture Research
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    • 제20권4호
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    • pp.66-84
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    • 2003
  • Objectve : Recent stuides suggested that there is a strong correlation between acupuncture stimulation and its cortical activation. Another study showed that either positive or negative BOLD effects could be observed depending on anatomical structure in acupuncture. Methods : 1) Subjects and paradigms: Two separate stimulation paradigms were performed in this study. To see the effects of electro-acupuncture stimulation on K7(Fuliu), the experiment was carried out on six healthy volunteers, using the gradient echo sequence with the 3.0T whole-body MRI system(ISOL). After the needle insertion on right K7(Fuliu), 2 Hz of electric stimulation was given for 30 seconds, repeated five times, with 30 seconds' intervals. During the intervals while there was no electro-stimulation, the subjects performed motor task as a reference. The image analysis including motion correction, talairach transformation, and smoothing was done using SPM99. Results: The electro-acupuncture stimulation on K7(Fuliu) activated Brodmann's Areas of 9, 19, 23, 24, 31, 32, 39 which may be the central pathways of the electro-acupuncture stimulation on K7(Fuliu) and those brain areas may be related with the function of the electro-acupuncture stimulation on K7(Fuliu).

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소규모(小規模) 상업(商業) 건축물(建築物)에 나타난 대중적(大衆的) 전통표현(傳統表現) 특성(特性)에 관(關)한 연구(硏究) - 대구시(大邱市) 인근지역(隣近地域) 상업건축물(商業建築物)을 사례(事例)로 - (A Study on the Characteristics of Popular Traditional Expression in Small Commercial Buildings - Focus on a commercial buildings in a suburb of Taegu -)

  • 이동찬;장수석;김정재
    • 건축역사연구
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    • 제12권4호
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    • pp.63-79
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    • 2003
  • Considering the established research about the characteristics of traditional expression in a contemporary korean architecture, there are two critical problems. the one is that the extent of a case is limited to a public building and a large exhibition building. the other is that the angle of research focus on the viewpoint of specific a level. To settle these problems and supplement a established research, this study is to investigate and analyze the characteristics of popular traditional expression in small commercial buildings. In A viewpoint on the expansion of a case and a various angle, A small commercial buildings is selected as a case. because it is felt that the populace's taste vis-a-vis traditional expression. To investigate and analyze, A main analytic criterion is follows. 1) A expressional method on traditional architectural form 2) A expressional aspect by architectural element 3) A expressional aspect in architectural material 4) A expressional aspect in architectural structure. In consequence we can find out the following results in the process of analysis. 1) In expressional method on traditional architectural form, the traditional expression is represented as the imitation and transformation of a traditional folk house forms, and the embodiment of traditional image 2) In expressional aspect by architectural element, the traditional expression elements is mainly represented at a straw roof and a mud-plastered wall 3) the traditional expression material is mainly straw, timber, small wood boards and mud 4) In expressional aspect in architectural structure, the traditional expression is represented from the viewpoint of decorative expression.

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대중스타의 패션 트렌드에 관한 연구 (A Study on the Fashion Trends of a Popular Star)

  • 이은숙
    • 한국의상디자인학회지
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    • 제10권1호
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    • pp.69-78
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    • 2008
  • A new coinage which calls a modern was appeared variously by values, taste, feature of lifestyle and the meaning of a new coinage has influence in the change of lifestyle. Particularly a popular star is a person who situates in the center of a new coinage, his role, behavior, and appearance have great influence in the birth of a new coinage. He is a fashion leader as well as the object of fashion imitation to the new generation being sensitive for fashion. As his fashion is appeared with important fashion icon in fashion market, fashion companies have developed actively star marketing marking him as an advertising model. Therefore, because the fashion trends of a popular star introduce season's fashion trends and can be important factor forecasting fashion behavior of consumer, this study aims at analysis for fashion trends of a popular star including a public entertainer. The dates of this study were collected by TV drama, internet, and magazines, etc. The fashion trends were divided into feminine fashion trend, sexy fashion trend, tomboy fashion trend, and retro fashion trend. Feminine fashion trend was based on feminity but it was classified in masculine look, simple look, chic look, and natural & romantic look according to the standard of a transformation of feminine image. Sexy fashion trend was divided into two sexy images according to the method wrapping oneself in a dress and the method exposing a specific body part. Tomboy fashion trend could be the immature boyish style which concealed bust or hip or pelvis symbolizing feminity. Retro fashion trend could be style being based on 1980's style and Y line. Fashion items as leggings, baby doll dress, tunic style, dot pattern, garsonne look were come into fashion.

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실천공동체로서의 네트워크 발달에 대한 질적 사례연구 : 서울시 S구 재가복지연합회 사례를 중심으로 (A Qualitative Case Study on the Development of Network as Communities of Practice in Welfare Network of S District in Seoul, Korea)

  • 김영숙;임효연
    • 한국사회복지학
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    • 제62권3호
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    • pp.299-321
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    • 2010
  • 본 연구는 사회복지사들의 네트워크 활동을 실천공동체 관점에서 보고 발달과정상의 내용을 분석하고자 했다. 연구는 질적사례 연구방법으로 수행했으며, 연구에는 10명의 사회복지사가 참여했다. 심층면담으로 자료를 수집했고 수집된 자료는 Strauss와 Corbin(1990)이 제시한 지속적 비교방법으로 분석했다. 잠재기의 주요내용은 "현실타개를 위한 아래로부터의 연대"로 분석되었다. 결합기에는 "규범적 가치기반의 획득"이 주요내용으로 분석되었다. 성숙기에는 "연대의 강화", "정체성의 재확인"이 있었다. 유지기의 주요내용은 "공동체 고유이미지 구성", "사적연대에서 공적인 연대로의 전환"으로 분석되었다. 변형기에는 지식공유와 실천이 결합된 "혼합공동체로의 전이"가 주요내용으로 분석되었다.

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가상 양시점화 방법을 이용한 비전기반 3차원 손 인터페이스 (Vision based 3D Hand Interface Using Virtual Two-View Method)

  • 배동희;김진모
    • 한국게임학회 논문지
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    • 제13권5호
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    • pp.43-54
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    • 2013
  • 최근 3차원 분야의 지속적인 발전으로 인해 보다 사실적이고 실감나는 영상을 경험할 수 있게 되었고 게임과 같은 다양한 응용분야에서 활용가능하게 되었다. 특히 가상환경에서의 객체들과 상호작용하며 이를 제어하는 증강현실 분야에 많은 발전을 가져왔다. 본 연구는 한 대의 카메라를 활용한 가상 양시점화 방법을 통해 3차원 공간의 객체를 제어하는 3차원 사용자 인터페이스를 제안한다. 이를 위해 임의의 두 카메라 위치 사이의 변환 정보를 담고 있는 호모그래피(homography) 행렬을 계산하고, 한 대의 카메라에서 얻은 2차원 손 좌표, 호모그래피 행렬 그리고 카메라의 투영행렬을 이용하여 3차원 좌표의 복원을 수행한다. 이러한 방법을 통해 보다 정확하고 빠른 3차원 정보를 얻을 수 있게 된다. 이는 두 대의 카메라를 동시에 구동할 때보다 연산량이 감소하여 실시간 처리에 효과적일 수 있으며 경제적인 부담도 줄일 수 있는 장점을 가지고 있다.

선형특징을 사용한 불변 영상정합 기법 (Invariant Image Matching using Linear Features)

  • 박세제;박영태
    • 전자공학회논문지S
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    • 제35S권12호
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    • pp.55-62
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    • 1998
  • 두개의 영상을 정합 하는 것은 많은 컴퓨터 시각장치의 응용과정 중 기본적인 과정이다. 본 논문에서는 선형특징을 사용한 정합기법으로서 회전각도와 크기비율에 불변한 영상정합 기법을 제안한다. 영상은 edge 검출, 세선화, 선형화 과정에 의해 선형 세그먼트의 집합으로 묘사된다. 세그먼트 사이의 각도차이와 새로운 거리척도에 의한 크기비율을 사용해 Hough 공간에서 최대로 일치하는 변환 파라메터를 추정한다. 추정된 파라메터는 1단계 relaxation과 Hough 기법으로 이루어진 고속 선형특징 정합과정에 의해 검증된다. 제안한 기법은 변환 파라메터에 대한 사전정보를 필요로 하지 않으며 추출된 선형 세그먼트 크기의 변화에 민감하지 않은 특성과 기존의 relaxation 기법에 비해 빠른 처리속도를 가진다.

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