• 제목/요약/키워드: reverse contrast images

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GaAs 웨이퍼의 적외선 영상기법 및 콘트라스트 반전 영상에 대한 새로운 해석 (Infrared Imaging and a New Interpretation on the Reverse Contrast Images in GaAs Wafer)

  • 강성준
    • 한국정보통신학회논문지
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    • 제20권11호
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    • pp.2085-2092
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    • 2016
  • IC 기판의 가장 중요한 성질들의 하나는 넓은 영역에 걸쳐 균일해야만 한다는 것이다. 웨이퍼 결함 분석의 다양한 물리적 접근 방법 중에서 적외선 조사 기법에 특별한 관심이 모아지고 있다. 특히, 높은 공간적 분해력을 가지고 있는 근적외선 흡수 방법은 반-절연 GaAs 내의 결함들을 직접적으로 관찰하는데 이용되고 있다. 적외선 전송에 기초를 둔 이 기법은 신속하고 비파괴 적이다. 이 방법은, 직접적으로 GaAs 반도체의 적외선 영상은 결함의 광흡수 작용에 기인한 것임을 밝히고 있다. 반-절연 GaAs 내의 EL2에 관련된, 비 균일 적으로 분포된 결함들의 적외선 흡수 영상에서 콘트라스트가 반전되는 현상에 대해 새로운 모델을 제시하고 있다. 저온 포토퀀칭 실험은, 직접적인 방법으로, GaAs 웨이퍼의 콘트라스트 반전 영상은 밴드갭의 지엽적인 변동이나 전하 재분포에 의한 것이 아니라 흡수와 산란의 두 메커니즘에 의한 것임을 증명하고 있다.

The efficacy of the reverse contrast mode in digital radiography for the detection of proximal dentinal caries

  • Miri, Shimasadat;Mehralizadeh, Sandra;Sadri, Donya;Motamedi, Mahmood Reza Kalantar;Soltani, Parisa
    • Imaging Science in Dentistry
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    • 제45권3호
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    • pp.141-145
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    • 2015
  • Purpose: This study evaluated the diagnostic accuracy of the reverse contrast mode in intraoral digital radiography for the detection of proximal dentinal caries, in comparison with the original digital radiographs. Materials and Methods: Eighty extracted premolars with no clinically apparent caries were selected, and digital radiographs of them were taken separately in standard conditions. Four observers examined the original radiographs and the same radiographs in the reverse contrast mode with the goal of identifying proximal dentinal caries. Microscopic sections $5{\mu}m$ in thickness were prepared from the teeth in the mesiodistal direction. Four slides prepared from each sample used as the diagnostic gold standard. The data were analyzed using SPSS (${\alpha}=0.05$). Results: Our results showed that the original radiographs in order to identify proximal dentinal caries had the following values for sensitivity, specificity, positive predictive value, negative predictive value, and accuracy, respectively: 72.5%, 90%, 87.2%, 76.5%, and 80.9%. For the reverse contrast mode, however, the corresponding values were 63.1%, 89.4%, 87.1%, 73.5%, and 78.8%, respectively. The sensitivity of original digital radiograph for detecting proximal dentinal caries was significantly higher than that of reverse contrast mode (p<0.05). However, no statistically significant differences were found regarding specificity, positive predictive value, negative predictive value, or accuracy (p>0.05). Conclusion: The sensitivity of the original digital radiograph for detecting proximal dentinal caries was significantly higher than that of the reversed contrast images. However, no statistically significant differences were found between these techniques regarding specificity, positive predictive value, negative predictive value, or accuracy.

악관절이 방사선상에 의한 비교 연구 (A COMPARATIVE STUDY OF RADIOGRAPHIC LANDMARKS OF T.M.J. BY VARIOUS TECHNIQUES)

  • 이유동
    • 치과방사선
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    • 제4권1호
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    • pp.31-37
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    • 1974
  • The author has studied roentgenographic images of temporomandibular articulation using various conventional roentgenographies. The roentgenographic images have obtained by application of the contrast media on the glenoid fossa and condylar head in a human dry skull. Comparing the various roentgenograms by Modified Transcranial projection, A-P T.M. articulation projection, Reverse Towne projection, Mayer projection and Bregma-Menton projection. The author has drawn following results. 1. The sharp radiogaphic details were obtained by all technics used except the Bregma-Menton projection, which seemed to be impractical to the study of T.M.J. because of to be shortened the image of condylar head. 2. The best image of the condyle-fossa relationship was appeared by Modified Transcranial projection and better image was acquired by Orbito-Ramus projection, but there were all inferior in Reverse Towne projection, Mayer projection and Bregma-Menton projection. 3. In all of the above techniques, the radiographic images of condylar head were clear and were appeared to be the convex type in Modified Transcranial projection, the angled type in Orbito-Ramus and Reverse Towne projection, the flat type in Mayer projection and the distorted angled type in Bregma-Menton projection. 4. The radiographic image of condylar head was shortened in Bregma-Menton projection only and was magnified somewhat in other projection.

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역재분포 소견과 심근조영 심초음파에서 보인 심내막하경색과의 관계 (Correlation between Reverse Redistribution and Subendocardial Myocardial Infarction Observed in Myocardial Contrast Echocardiography)

  • 김성은;최원식;권준
    • 대한핵의학회지
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    • 제34권3호
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    • pp.228-233
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    • 2000
  • 목적: 역재분포(reverse redistribution)는 심근관류영상에서 초기 thallium 섭취가 정상이거나 정상에 가까운 지역이 재분포 영상에서는 결손으로 보이는 것으로 정의되는데 역재분포의 특성을 더욱 잘 이해하기 위하여 심근조영 심초음파(myocardial contrast echocardiography, MCE)에 의해 진단된 심내막하심근경색과 심근 SPECT 영상에서 관찰되는 역재분포를 연관시켜 분석하였다. 대상및 방법: 급성심근경색으로 진단된 20명의 환자들을 대상으로 경피적 관동맥 성형술로 재혈관화 한 후에 심근조영 심초음파를 시행 한 후 24시간 이내에 심근 SPECT를 시행하였다. 심근조영 심초음파로 미세혈관분포에 대한 조영증강 정도를 세 단계로 평가하였고(1: 정상 조영증강, 0.5: 부분 조영증강, 0: 조영증강 없음) 심내막하경색의 진단은 심외막에만 국한되어 조영이 되고 심내막이 조영되지 않을 경우로 하였다. 심근관류 결손은 4단계(경도, 중등도, 고도, 정상)로 나누었고 24시간 지연영상에서 1단계 이상 나빠지는 경우 역재분포가 존재한다고 판단하였다. 비모수적 Kendall 상관 계수를 SAS 통계 패키지를 이용하여 계산하였다. 결과: 20예 중 15예(75%)가 일치하였다(8예는 양쪽 검사 모두에서 양성, 7예는 음성). 통계 분석상 심근조영심초음파 양성(심내막하 심근경색)인 예와 SPECT 양성(역재분포인 예)인 예의 사이에는 Kendall 상관계수가 0.5025였고 P값이 0.0285였다. 결론: 급성심근경색 환자에서 재혈관화치료 후에 관찰되는 역재분포 소견은 심근조영 심초음파에 보이는 심내막하 심근경색 소견과 유의한 연관이 있었다.

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GaAs 웨이퍼의 대역단 영상에 대한 정량적 해석 (Quantitative Analysis on Near Band Edge Images in GaAs Wafer)

  • 강성준;나철훈
    • 한국정보통신학회논문지
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    • 제21권5호
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    • pp.861-868
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    • 2017
  • 도핑 되지 않은 반 절연 LEC GaAs내의 EL2와 얕은 준위 분포를 영상화하기 위해 대역단 적외선 영상 기법을 활용했다. 대역단 적외선 투사 매핑에 근거한 본 기법은 분석 속도가 빠르고 비파괴적인 방법이다. EL2 흡수 영상이 콘트라스트 반전되는 대역단 부근에 대한 정량적인 해석은 아직 보고되지 않고 있다. 본 논문은 대역단 부근에서 영상의 특정 부분(cell, wall)에 대한 포토퀀칭 메커니즘의 스펙트럼-, 공간- 및 온도- 종속성을 논하고 있다. 결함 부분별(EL2w, EL2b)로 포토퀀칭 개시점이 다른 것은 불순물 종류의 차이로 인한 서로 다른 전기적 작용에 기인한 것으로 해석할 수 있다. 전위(dislocation) 밀도가 높은 곳에서는 EL2b 밀도는 약간 적은 반면 EL2w 밀도는 보다 많다는 것을 정량적 해석으로부터 확인 했다.

기술적인 화질 지표 조절양 최적화를 통한 감성 화질 향상 방안 (Methodologies to Improve Emotional Image Qualities by Optimizing Technological Image Quality Metrics)

  • 유재희
    • 감성과학
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    • 제20권1호
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    • pp.57-66
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    • 2017
  • 다양한 이미지 샘플의 Eye test를 바탕으로 기술적인 화질 지표 조절을 통하여 감성 화질을 최적화 시키는 방법이 소개된다. 여러 가지 이미지 콘텐츠의 다양한 이미지에 대하여, 콘트라스트, 명도, 채도 화질 지표 톤 커브를 사용하여 평가가 수행 되었다. 이미지 화질 향상에 기여하는 우선순위는 명암, 채도 및 밝기 순으로 분석 되었다. 이미지 감성 화질 측정치의 기술적인 화질 지표 변화에 따른 기울기의 공통점을 살펴본 결과, 거의 0, 중간 그리고 최대 기울기의 영역으로 구성된 함수 형태로 모델링을 할 경우, 기존의 역 U 형태의 성질 뿐 아니라 log 또는 포화 형태의 감성 화질 변화까지 분석 가능함을 알 수 있었다. 단일 및 복수의 화질 지표의 경우에 대하여도 화질 개선 방안이 모색되었으며, 기존 및 본 논문에서 분석된 결과를 위한 새로운 함수가 소개 되었다. 복수의 통합적 이미지 화질 지표를 통하여 향상 시킬 경우 오직 몇몇 한정된 지표 제어의 경우에만 실현 가능하다는 것을 알 수 있었다. 또한, 화질 향상 방법은 영상 콘텐츠에 따라 크게 차이가 없음을 알 수 있었다.

현대회화에서 드러난 해체의 형식론에 관한 연구 -타의적 해체와 자의적 해체의 성격규정을 중심으로- (A study of the destructive styles from Contemporary Paintings - Focused on distinguishing enmity-destruction and self-destruction -)

  • 박기웅
    • 조형예술학연구
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    • 제7권
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    • pp.5-63
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    • 2005
  • Generally, the meanings of destruction are related in the meaning of demolition, breakdown, into fragments ... and so on, and the similar meanings are twist, crush, demolish, split, cut, into pieces , break up ... etc. Further, it has related in the cruelty and destructive heart which are linked with orgy, Sadism, Necrophilia and so on. The meanings are also expressed by the initial , which are deprivation, deface, defame, deform, degrade, delegitimize, denounce , deride, destroy, devalue, as well as debase, debunk, declaim, declassify, decry, delete, denigrate, deprecate, despise or detract ...and so on. Dario Gamboni has discussed the meaning in his book as two categories Iconoclasm and Vandalism. And the similar meanings could be found in the words which has the initial of , like abase, abate, abhor, abjure, abolish, abridge, abuse ...and so on. Even though the distinct meanings of Iconoclasm and Vandalism, it is not easy to distinguish clearly between the differences when the results are accomplished in contemporary paintings because of the similarity of the results. In korean vocabulary there are no similar words to distinguish between the meanings of destruction and deconstruction, and the deconstruction is not recorded in the general dictionaries. However the meaning of is diminishing, separation, contrast and so on. So the unification of the word as do-construction is not construct, minus construction, reverse construction. And Vincent Ditch explained that there are the meaning of destroy the text. From Jacques Derrida, the deconstruction strategy is to criticise the world of traditional metaphysics and logocentrism, and not to reconstruire the philosophical meaning of texts but $d\'{e}construire$ them. And Saussure emphasized that the signifers could have more meaning that there can be more signified in traditional texts in the art. as a result, deconstruction is explained that there are many signified meanings in a signifer. In this thesis , from using the meanings of destruction and deconstruction, to distinguish the expressive skills in contemporary art works are arising. Therefore, special methods which are linked in the destruction styles are selected. As a result, the two different purposes of destruction is arising, one is enmity destruction and the other is self destruction another word, auto destruction or destruction to create The enmity destruction can be distinguished by the two category Iconoclasm and Vandalism. They come from the moment of different historical aspect is arising and want to attack the Icon or masterpiece this concept is from the study of John Philips and especially iconoclasm is linked with religious and artistic heart, but Vandalism is come from the political attack. Sometime, this distinguish is not clearly arising, because the two aspects are co-related in the attack. As a result, firstly, the Iconoclastic controversy had arisen in the methods of Dadaism which has developed by Man Ray, Francis Picabia and Marcel Duchamp. They want to attack the pre-established master-pieces and painting spaces, and they had 'non-artistic attitude' not to be art. Since 1980, the German artist Anselm Kiefer adapted the methods and made them his special skills so he had tried to paint tough brush strokes and draw with hugh pallette image line and fire and water images , they can be the image attack as the Iconoclasm. secondly, the model of vandalism is to be done by hammer, drill, canon and so on. the method is to attack the content of painting. Further, the object of destruction is bound by cords and iron lings to demolish or to declare the authority of pre-statues; it symbolize the pre-authority is gone already. Self-destruction based paintings are clearly different in the purpose of approaching the art work. First of all, they can be auto-destruction, creative destruction and metamorphosis destruction, which is linked with the skill the material aspect and basic stature, and sign destruction or signifier destruction, which is link with the inner meaning destruction that is considered as the Semiotical destruction in post-modern paintings. Since 1960, the auto destruction is based on the method of firing, melting, grinding and similar skills, which is linked with Neo-Dada and reverse-assemblage. Metamorphosis destruction is strongly linked with the basic inner heart price and quality, so it can be resulted in the changedness of expectation and recognition. Tony Cragg has developed the skills to metamorphose the wood as stone or iron as cloth and stone as sponge and rubber and so on. The researcher has developed the same style in the series of since 2003. The other self-destructive methods are found in the skill of sign destruction. In the methods the meaning of the art is not fixed as one or two, but is developed multi-meaning and differ from original starting situation, so Jacques Derrida called the difference meaning in deconstruction. It is the destruction of textes. These methods are accomplished by David Salle, Francesco Clemente, and recently Tracy Emin, who has developed the attacking heart in the spectators' emotion. Sometime in the method of self-destruction, it is based on horror and shock, the method is explored by Demian Hirst and Jakes and Dinos Chapman. Their destructive styles stimulate ambivalent heart and destroy original sign of girl and animals.

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