• 제목/요약/키워드: Image Deformation

검색결과 364건 처리시간 0.036초

휴대폰 카메라용 비구면렌즈 사출성형의 수치해석 (Numerical analysis of injection molding of aspheric lenses for a mobile phone camera module)

  • 박근;엄혜주
    • 한국금형공학회:학술대회논문집
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    • 한국금형공학회 2008년도 하계 학술대회
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    • pp.143-148
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    • 2008
  • In order to produce high-quality optical components, aspheric lenses have been widely applied in recent years. An aspheric lens consists of aspheric surfaces instead of spherical ones, which causes difficulty in the design process as well as the manufacturing procedure. Although injection molding is widely used to fabricate optical lenses owing to its high productivity, there remains lots of difficulty to determine appropriate mold design factors and injection molding parameters. In the injection molding fields, computer simulation has been effectively applied to analyze processes based on the shell analysis so far. Considering the geometry of optical lenses, a full-3d simulation based on solid elements has been reported as a reliable approach. The present work covers three-dimensional injection molding simulation and relevant deformation analysis of an injection molded plastic lens based on 3d solid elements. Numerical analyses have been applied to the injection molding processes of three aspheric lenses for an image sensing module of a mobile phone. The reliability of the proposed approach has been verified in comparison with the experimental results.

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A Review on Remote Sensing and GIS Applications to Monitor Natural Disasters in Indonesia

  • Hakim, Wahyu Luqmanul;Lee, Chang-Wook
    • 대한원격탐사학회지
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    • 제36권6_1호
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    • pp.1303-1322
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    • 2020
  • Indonesia is more prone to natural disasters due to its geological condition under the three main plates, making Indonesia experience frequent seismic activity, causing earthquakes, volcanic eruption, and tsunami. Those disasters could lead to other disasters such as landslides, floods, land subsidence, and coastal inundation. Monitoring those disasters could be essential to predict and prevent damage to the environment. We reviewed the application of remote sensing and Geographic Information System (GIS) for detecting natural disasters in the case of Indonesia, based on 43 articles. The remote sensing and GIS method will be focused on InSAR techniques, image classification, and susceptibility mapping. InSAR method has been used to monitor natural disasters affecting the deformation of the earth's surface in Indonesia, such as earthquakes, volcanic activity, and land subsidence. Monitoring landslides in Indonesia using InSAR techniques has not been found in many studies; hence it is crucial to monitor the unstable slope that leads to a landslide. Image classification techniques have been used to monitor pre-and post-natural disasters in Indonesia, such as earthquakes, tsunami, forest fires, and volcano eruptions. It has a lack of studies about the classification of flood damage in Indonesia. However, flood mapping was found in susceptibility maps, as many studies about the landslide susceptibility map in Indonesia have been conducted. However, a land subsidence susceptibility map was the one subject to be studied more to decrease land subsidence damage, considering many reported cases found about land subsidence frequently occur in several cities in Indonesia.

아리랑 5호 위성 영상에서 수계의 의미론적 분할을 위한 딥러닝 모델의 비교 연구 (Comparative Study of Deep Learning Model for Semantic Segmentation of Water System in SAR Images of KOMPSAT-5)

  • 김민지;김승규;이도훈;감진규
    • 한국멀티미디어학회논문지
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    • 제25권2호
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    • pp.206-214
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    • 2022
  • The way to measure the extent of damage from floods and droughts is to identify changes in the extent of water systems. In order to effectively grasp this at a glance, satellite images are used. KOMPSAT-5 uses Synthetic Aperture Radar (SAR) to capture images regardless of weather conditions such as clouds and rain. In this paper, various deep learning models are applied to perform semantic segmentation of the water system in this SAR image and the performance is compared. The models used are U-net, V-Net, U2-Net, UNet 3+, PSPNet, Deeplab-V3, Deeplab-V3+ and PAN. In addition, performance comparison was performed when the data was augmented by applying elastic deformation to the existing SAR image dataset. As a result, without data augmentation, U-Net was the best with IoU of 97.25% and pixel accuracy of 98.53%. In case of data augmentation, Deeplab-V3 showed IoU of 95.15% and V-Net showed the best pixel accuracy of 96.86%.

Failure pattern of twin strip footings on geo-reinforced sand: Experimental and numerical study

  • Mahmoud Ghazavi;Marzieh Norouzi;Pezhman Fazeli Dehkordi
    • Geomechanics and Engineering
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    • 제32권6호
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    • pp.653-671
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    • 2023
  • In practice, the interference influence caused by adjacent footings of structures on geo-reinforced loose soil has a considerable impact on their behavior. Thus, the goal of this study is to evaluate the behavior of two strip footings in close proximity on both geocell and geogrid reinforced soil with different reinforcement layers. Geocell was made from geogrid material used to compare the performance of cellular and planar reinforcement on the bearing pressure of twin footings. Extensive experimental tests have been performed to attain the optimum embedment depth and vertical distance between reinforcement layers. Particle image velocimetry (PIV) analysis has been conducted to monitor the deformation, tilting and movement of soil particles beneath and between twin footings. Results of tests and PIV technique were verified using finite element modeling (FEM) and the results of both PIV and FEM were used to utilize failure mechanisms and influenced shear strain around the loading region. The results show that the performance of twin footings on geocell-reinforced sand at allowable and ultimate settlement ranges are almost 4% and 25% greater than the same twin footings on the same geogrid-reinforced sand, respectively. By increasing the distance between twin footings, soil particle displacements become smaller than the settlement of the foundations.

Extra-phase Image Generation for Its Potential Use in Dose Evaluation for a Broad Range of Respiratory Motion

  • Lee, Hyun Su;Choi, Chansoo;Kim, Chan Hyeong;Han, Min Cheol;Yeom, Yeon Soo;Nguyen, Thang Tat;Kim, Seonghoon;Choi, Sang Hyoun;Lee, Soon Sung;Kim, Jina;Hwang, JinHo;Kang, Youngnam
    • Journal of Radiation Protection and Research
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    • 제44권3호
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    • pp.103-109
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    • 2019
  • Background: Four-dimensional computed tomographic (4DCT) images are increasingly used in clinic with the growing need to account for the respiratory motion of the patient during radiation treatment. One of the reason s that makes the dose evaluation using 4DCT inaccurate is a change of the patient respiration during the treatment session, i.e., intrafractional uncertainty. Especially, when the amplitude of the patient respiration is greater than the respiration range during the 4DCT acquisition, such an organ motion from the larger respiration is difficult to be represented with the 4DCT. In this paper, the method to generate images expecting the organ motion from a respiration with extended amplitude was proposed and examined. Materials and Methods: We propose a method to generate extra-phase images from a given set of the 4DCT images using deformable image registration (DIR) and linear extrapolation. Deformation vector fields (DVF) are calculated from the given set of images, then extrapolated according to respiratory surrogate. The extra-phase images are generated by applying the extrapolated DVFs to the existing 4DCT images. The proposed method was tested with the 4DCT of a physical 4D phantom. Results and Discussion: The tumor position in the generated extra-phase image was in a good agreement with that in the gold-standard image which is separately acquired, using the same 4DCT machine, with a larger range of respiration. It was also found that we can generate the best quality extra-phase image by using the maximum inhalation phase (T0) and maximum exhalation phase (T50) images for extrapolation. Conclusion: In the present study, a method to construct extra-phase images that represent expanded respiratory motion of the patient has been proposed and tested. The movement of organs from a larger respiration amplitude can be predicted by the proposed method. We believe the method may be utilized for realistic simulation of radiation therapy.

현대회화에서의 형태와 물질 -Digital Transfiguration에 관한 연구- (Digital painting: Image transfonnation, simulation, heterologie and transfonnation)

  • 정숙영
    • 조형예술학연구
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    • 제10권
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    • pp.161-181
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    • 2006
  • The words which appeared in my theoretical study and work are image transformation to digital painting, simulation, heterologie and transfiguration, etc. Firstly, let's look into 'digital era' or 'new media era'. Nowadays, the image world including painting within the rapid social and cultural change, which is called as digital era, is having the dramatic change. Together with the development of scientific technology, large number of events which was deemed to be impossible is happening as real in image world Moreover, these changes in image world is greatly influencing to our life. The word which compresses this change of image world and shows is 'digital'. Digit, which means fingers in Latin, indicates separately changing signal, and to be more narrow, it indicates the continual signal of '0' and ' 1' in computer. The opposite word is 'analogue'. As analogue is the word meaning 'infer' or 'similarity', it indicates the signal or form which continuously changes along the series of time when it is compared to digital. Instead of analogue, digital is embossed as a major ruler along the whole area of our current culture. In whole culture and art area, and in whole generalscience, digital is appearing as it has the modernism and importance. The prefix, 'digital', e.g. digital media, digital culture, digital design, digital philosophy, etc, is treated as the synonym of modernism and something new. This advent of digital results the innovative change to the image world, creates the new beauty experience which we could not experience before, and forecasts the formation of advanced art and expansion of creative area. Various intellectual activities using computer is developing the whole world with making the infrastructure. Computer in painting work immediately accomplishes the idea of painters, takes part in simulation work, contingency such as abrupt reversal, extraction, twisting, shaking, obscureness, overlapping, etc, and timing to stimulate the creativity of painters, and provides digital formative language which enables new visual experience to the audience. When the change of digital era, the image appeared in my work is shown in 'transfiguration' like drawing. The word, 'transfiguration' does not indicate the completed and fixed real substance but indicate endlessly moving and floating shape. Thus, this concept is opposite to the substantial consideration, so that various concepts which is able to replace this in accordance with the similar cases are also exist such as change, deterioration, mutation, deformity of appearance and morphing which is frequently used in computer as a technical word. These concepts are not clearly classified, and variably and complicatedly related. Transfiguration basically means the denial of "objectivity' and '(continual) stagnation' or deviation from those. This phenomenon is appeared through the all art schools of art ever since the realism is denied in the 19th century. It is called as 'deformation' in case of expressionism, futurism, cubism, etc, in the beginning of the century, which its former indication is mostly preserved within the process of structural deviation and which has the realistic limit which should be preserved. On the contrary, dramatic transfiguration which has been showing in the modern era through surrealism is different in the point that dramatic transfiguration tends to show the deterioration and deviation rather than the preservation of indicated object. From this point, transfiguration coming out from morphing using computer deteriorates and hides the reality and furthermore, it replaces the 'reality'. Moreover, transfiguration is closely approached to the world of fake or 'imaginary' simulation world of Baudrillard. According to Baudrillard, the image hides and deteriorates the reality, and furthermore, expresses 'not existing' to 'imaginary' under the name of transfiguration. Certain reality, that is, image which is absent from the reality is created and overflowed, so that it finally replaces the reality. This is simulation as it is said by Baudrillard. In turn, Georges Bataille discusses about the image which is produced by digital technology in terms of heterologie. Image of heterologie is the visual signal which is established with the media. Image of media is to have the continuous characteristics of produce, extinction, and transformation, and its clear boundary between images becomes meaningless. The meaning of composition, excess, violation, etc of digital image is explained to heterological study or heteologie suggested as important meaning of Georges Bataille who is a heretic philosopher. As the form and image of mutation shows the shape in accordance with mechanical production, heterologie is introduced as very low materialism (or bas materialisme), in this theory. Heterologie as low materialism which is gradually changing is developing as a different concept and analysis because of the change of time in the late 20s century beside high or low meaning. Including my image, all images non-standardizes and transforms the code. However, reappearance and non-standardization of this code does not seem to be simple. The problem of transformation caused by transfiguration which appears in my digital drawing painting, simulation, heterologie, etc, are the continual problems. Moreover, the subject such as existence of human being, distance from the real life, politics and social problems are being extended to actual research and various expressing work. Especially, individual image world is established by digital painting transfiguration technique, and its change and review start to have the durability. The consciousness of observers who look at the image is changing the subject. Together with theoretical research, researchers are to establish the first step to approach to various image change of digital era painting through transfiguration technique using our realistic and historical image.

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함수비에 따른 불포화 도로성토의 동적 안정성 평가 (Dynamic-stability Evaluation of Unsaturated Road Embankments with Different Water Contents)

  • 이충원;히고 요스케;오카 후사오
    • 한국지반공학회논문집
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    • 제30권6호
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    • pp.5-21
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    • 2014
  • 지진시 불포화 도로성토의 붕괴는 지하수 및 강우의 침투에 기인한 함수비의 증가가 그 원인이 됨이 지적되어 왔다. 따라서, 이와 같은 지반재해의 방지를 위한 합리적 보강방안 및 적절한 설계기준의 정립을 위해 불포화 도로성토의 동적안정성 및 변형모드에 대한 함수비의 영향을 연구할 필요가 있다. 본 연구에서는 불포화 도로성토의 변형 및 파괴거동에 대한 함수비의 영향을 연구하기 위해 상이한 함수비를 갖는 도로성토 모형에 대하여 동적 원심모형실험을 진행하였다. 본 실험에서는 도로성토 모형에 대한 동적하중 부가시의 변위, 간극수압 및 가속도의 계측을 통해 최적함수비 부근 및 최적함수비보다 높은 함수비를 갖는 불포화 도로성토에 대한 동적 거동을 고찰하였다. 이와 함께, 화상해석에 의한 변위 및 변형율 분포의 분석을 통하여 최적함수비보다 높은 함수비를 갖는 불포화 도로성토의 변형모드를 구명하였다. 이로부터 사면 천단부의 침하는 천단부 아래에서의 체적압축에 기인하며, 구속압력이 작은 사면 선단부 및 사면 표면부 부근에서는 체적팽창을 동반한 큰 전단변형이 발생함을 확인하였다.

NeRF, PBD 및 병렬 리샘플링을 결합한 실시간 3D 볼륨 변형체 시각화 (Real-Time 3D Volume Deformation and Visualization by Integrating NeRF, PBD, and Parallel Resampling)

  • 권상민;전소진;박준이;김다솔;계희원
    • 한국컴퓨터그래픽스학회논문지
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    • 제30권3호
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    • pp.189-198
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    • 2024
  • 딥러닝 기반 모델과 물리 시뮬레이션을 결합한 연구는 의료 분야에서 중요한 발전을 이루고 있다. 이는 의료영상 데이터에서 필요한 정보를 추출하고, 물리적 법칙을 기반으로 골격 및 연조직의 변형에 대한 빠르고 정확한 예측을 가능하게 한다. 본 연구는 신경 방사 필드(NeRF), 위치 기반 동역학(PBD), 병렬 리샘플링을 융합하여 3D 볼륨데이터를 쉽게 생성하고 실시간으로 변형 및 시각화하는 시스템을 제안한다. NeRF는 2D 이미지와 카메라 좌표 정보를 사용해 고해상도 3D 볼륨 데이터를 생성하며, PBD는 물리 기반 시뮬레이션으로 획득한 데이터에 대한 실시간 변형과 상호작용을 가능하게 한다. 병렬 리샘플링은 사면체 메쉬와 GPU 병렬 처리를 통해 렌더링 효율성을 높인다. 이 시스템은 광선투사방식으로 렌더링 되어 빠른 실시간 시각화를 제공하며, 비싼 장비 없이 간단하게 3D 데이터를 생성하고 변형할 수 있어 공학, 교육, 의료 등 다양한 분야에서의 활용 가능성을 보여준다.

세포 자동 계수를 위한 광학현미경 이미지 처리 (Optical Microscope Image Processing for Automated Cells Counting)

  • 조미경;문상준;심재술
    • 한국정보통신학회논문지
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    • 제15권11호
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    • pp.2493-2499
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    • 2011
  • 나노 바이오산업의 발전과 더불어 세포 성장 과정에서 발견되는 세포의 이동, 분열, 통합, 아포토시스(apoptosis), 모양 변형, 세포들 간의 상호 작용 등을 포함하는 세포의 행동을 분석하기 위한 자동화된 시스템의 개발은 매우 중요하다. 본 연구에서는 세포 배양 과정에서 광학현미경을 통해 얻은 세포의 실시간 이미지들의 변화/변형 과정을 2D 또는 3D 분석 하기위한 전처리 방법과 세포와 클러스터(둘 이상의 세포의 결합)를 자동 식별하기 위한 방법, 시간의 흐름에 따라 변화되는 세포와 클러스터의 개수를 계수하기 위한 방법을 제시한다. 제안된 방법들은 30분 간격으로 촬영한 3T3 세포 배양 이미지들을 이용하여 실험하였으며 세포 및 클러스터를 분류하고 각각의 개수를 자동계수한 결과 평균 99.8%의 정확도를 보여 주었다.

볼록거울을 장착한 야간 사격훈련용 예광탄 탄도 모니터링 단일 카메라 시스템 (A Single Camera System Equipped Convex Mirror for Monitoring Tracer Bullet to Teach Night Firing Exercises)

  • 이인정
    • 한국통신학회논문지
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    • 제37C권9호
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    • pp.757-762
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    • 2012
  • 일반적으로 보통의 카메라는 초당 24 프레임을 갖는다. 이런 카메라를 가지고는 초당 1000m에 가까운 스피드를 가지는 총알을 촬영하기 어렵다. 하지만 볼록거울을 사용하면 스테레오그래픽 투영방법에 의해 긴 길이를 짧은 화면에 담을 수 있다. 대부분 고속 물체를 촬영하기 위해서는 초당 프레임이 보통 카메라의 몇 배에 달하는 카메라를 사용하거나 전자장비를 사용하여 여러 개의 카메라를 매우 작은 시간차를 두고 촬영하는 방법을 사용한다. 본 논문에서는 보통의 카메라와 볼록거울을 사용하여 야간 사격훈련용 예광탄 탄도 모니터링 시스템을 제안하며 250m 사격장에서 표적에 명중한지 아니한지 발견 가능함을 보였다.