• Title/Summary/Keyword: 변형재구성

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Newton's Huristics of the Discovery of Dynamics - Transformation and Synthesis (뉴턴의 발견법 - 변형재구성)

  • Park, Mi-Ra;Yang, Kyoung-Eun
    • Journal of Korean Philosophical Society
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    • v.148
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    • pp.157-181
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    • 2018
  • The aim of this essay is to identify elements of methodologies to investigate the development of Newtonian dynamics. This methodology involves the transformation and synthesis of preceding theories. My essay attempts to confirm my assertion by analyzing historical case of Newton's discovery of his dynamics. While discovering his mechanistic theory, Newton reconstructed theoretical concepts and structures of intellectual predecessors, such as Aristotle, Descartes, Galileo, and Kepler. Newton's synthesis was possible only after carefully reconstructing the appropriate and useful ideas of previous natural philosophers' ideas. As a result, Newtonian dynamics are completed with these modified and integrated concepts incorporated into Newton's law of motion and space-time concepts. This study consists of two parts. First, Lakatos' research program has been applied in order to analyze the structure of Newtonian dynamics. Second, the aforementioned methodologies of discovery are distilled from the case study.

Camber Reconstruction for a Prefab PSC Girder Using Collocated Strain Measurements (병치된 변형률 계측치를 이용한 프리팹 PSC 거더 캠버 재구성)

  • Kim, Hyun Young;Ko, Do Hyeon;Park, Hyun Woo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.2
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    • pp.151-162
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    • 2022
  • Prefab members have attracted attention because they can be mass-produced in factories through smart construction technology. For prefab prestressed concrete girders, it is important to manage the shapes of the girders properly from production to the pre-installation stage for consistency with the prefab floor plate during the erection process. This paper presents a camber reconstruction method using collocated strain measurements from the top and bottom of the prefab girder. In particular, the camber reconstruction method is applied to measured strain data in which the time-dependent behavior of concrete is considered after the introduction of prestress. Through Monte Carlo numerical simulations, the statistical accuracy of the reconstructed camber for a limited number of sensors, measurement errors, and nonlinear time-dependent behaviors are analyzed and validated.

Power-law Distributional Perturbation Analysis of the Topology of Reconstructed Genetic Networks (재구성된 유전자 네트워크의 섭동적(Perturbational) 토폴로지 변형 분석)

  • 이상근;장병탁
    • Proceedings of the Korean Information Science Society Conference
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    • 2003.10b
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    • pp.754-756
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    • 2003
  • DNA칩 기술로 얻어지는 대규모 섭동데이터(perturbation data)는 생물학적시스템(biological system)의 유전자네트워크(genetic network)를 재구성(reverse-engineering)하는데 있어 유용하다. 그러나 기존의 연구는 유전자 조절 관계의 규명이나 혹은 데이터를 설명하는 최적의 모델을 찾는 방향에만 관심을 두고 있고. 실험적인 한계로 인한 DNA칩 데이터의 오류가 재구성된 네트워크의 구조에 미치는 영향에 대해서는 중요하게 다루고 있지 않다. 본 논문에서는 유전자 네트워크의 멱함수(power-low) 분포 구조를 이용하여, 섭동 데이터의 오류가 재구성된 네트워크의 토폴로지(topology)에 미치는 영향을 분석하였다. 가상의 네트워크에 대한 데이터를 사용하여 실험한 결과, 데이터의 오류 정도에 따른 네트워크 토폴로지의 변형 양상을 관측할 수 있었다.

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Collision Configurations Reconstruction Using Deformation Shape and Deformation Severity of Car Body (차체의 변형상과 변형정도에 의한 자동차 충돌상황의 재구성)

  • 장인식;채덕병
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.1
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    • pp.171-180
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    • 2001
  • Collision accident reconstruction algorithm are developed based on the deformation shape and severity of a car body. At first, the body stiffness equation representing the force-deformation relationship is derived using finite element analysis for head on collision of two cars. The database of deformation shapes and energies is constructed for five different collision configurations; each configuration contains three velocity conditions. Deformation shapes are obtained using a curve fitting method and result in cubic polynomials. Deformation energies are calculated using a stiffness equation and deformation data. Three algorithms are developed to reconstruct collision configuration compared with constructed database. The developed algorithms show reasonably good performance to find collisions conditions for some test problems.

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Clinical Application of Dose Reconstruction Based on Full-Scope Monte Carlo Calculations: Composite Dose Reconstruction on a Deformed Phantom (몬테칼로 계산을 통한 흡수선량 재구성의 임상적 응용: 변형된 팬텀에서의 총제적 선량재구성)

  • Yeo, Inhwan;Xu, Qianyi;Chen, Yan;Jung, Jae Won;Kim, Jong Oh
    • Progress in Medical Physics
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    • v.25 no.3
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    • pp.139-142
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    • 2014
  • The purpose of this study was to develop a system of clinical application of reconstructed dose that includes dose reconstruction, reconstructed dose registration between fractions of treatment, and dose-volume-histogram generation and to demonstrate the system on a deformable prostate phantom. To achieve this purpose, a deformable prostate phantom was embedded into a 20 cm-deep and 40 cm-wide water phantom. The phantom was CT scanned and the anatomical models of prostate, seminal vesicles, and rectum were contoured. A coplanar 4-field intensity modulated radiation therapy (IMRT) plan was used for this study. Organ deformation was simulated by inserting a "transrectal" balloon containing 20 ml of water. A new CT scan was obtained and the deformed structures were contoured. Dose responses in phantoms and electronic portal imaging device (EPID) were calculated by using the XVMC Monte Carlo code. The IMRT plan was delivered to the two phantoms and integrated EPID images were respectively acquired. Dose reconstruction was performed on these images using the calculated responses. The deformed phantom was registered to the original phantom using an in-house developed software based on the Demons algorithm. The transfer matrix for each voxel was obtained and used to correlate the two sets of the reconstructed dose to generate a cumulative reconstructed dose on the original phantom. Forwardly calculated planning dose in the original phantom was compared to the cumulative reconstructed dose from EPID in the original phantom. The prescribed 200 cGy isodose lines showed little difference with respect to the "prostate" and "seminal vesicles", but appreciable difference (3%) was observed at the dose level greater than 210 cGy. In the rectum, the reconstructed dose showed lower volume coverage by a few percent than the plan dose in the dose range of 150 to 200 cGy. Through this study, the system of clinical application of reconstructed dose was successfully developed and demonstrated. The organ deformation simulated in this study resulted in small but observable dose changes in the target and critical structure.

The Simulation of Dies and Forming Processes for Clod Forging by Using Rigid-Plastic Finite Element Analysis (강소성 유한요소법을 이용한 냉간단조 금형 및 가공 공정 해석)

  • 이낙규;윤정호;양동열
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.13 no.6
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    • pp.1070-1081
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    • 1989
  • 본 논문의 목적은 일반적인 곡면을 갖는 냉간단조 공정을 컴퓨터 시뮬레이션 을 통해 해석하고자 강소성 유한요소법의 프로그램을 개발하고, 이를 축대칭 및 평면 변형 단조성형에 적용하고자 한다. 축대칭 문제로는 산업적으로 이용이 많은 치차 블랭크(gear blank) 형태의 예제를 선택하였고 평면변형으 경우 정밀 단조품의 하나인 터어빈 블레이드(turbine blade)를 평면변형 문제로 보아 해석하였다. 한편 심한 변형을 하는 후방압출과 같은 문제의 수렴성을 향상시키고 공정을 계속적으로 해석하 기 위하여 격자 재구성기법을 도입함으로서 냉간단조 문제의 일반적인 해석을 하도록 한다.

Evaluation on usefulness of three dimensional reconstructive computed tomography images after pedicle screws fixation (척추경 나사못 고정술 시행 후 3차원 재구성CT영상의 유용성 평가)

  • Kim, Hyeon-Ju;Jang, Hyun-Chul;Cho, Jae-Hwan
    • Journal of Digital Contents Society
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    • v.11 no.4
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    • pp.553-559
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    • 2010
  • By applying the various reformation techniques by using a circle raw data of after computed tomography image in the patient enforcing the spine screw fixation, this research tried to look into the various information including the exact location of the position of the screw spike and accuracy of an operation. In a clinical, by applying the or multi planar reformatting(MPR), that is the re-composition technique used mainly, maximum intensity projection (MIP), and volume rendering technique(VRT) and transformation removal from a register modifying VRT, video data were compared and were analyzed by the quantitative method and qualitative method. It is judged as the transformation volume rendering technique of the re-composition technique which is most useful in minimizing the artifact shadow by the exact location of the position of a screw and metal among the analysis and evaluation result computed tomography image reformation technique of the reformation image after the spine screw fixation.

Uncertainty of Measurements in the Analysis of Vehicle Accidents (차량 사고 분석에서 측정의 불확실성)

  • Han, In-Hwan;Park, Seung-Beom
    • Journal of Korean Society of Transportation
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    • v.28 no.3
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    • pp.119-130
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    • 2010
  • Reconstruction analysis of traffic accident is done by analyzing diverse data such as the road, accident traces and damage on the automobile. Most data can be a variable in the process of analysis, and measurement error of the data occurs from the investigator, tool and the given environment. Therefore, accident analysis always has some risks of measurement uncertainty. This research quantify the uncertainty in traffic accident analysis by conducting repetitive measurement experiments for variables with high probability of uncertainly such as length (i.e. geometric structure of the road, tire marks) and coefficient of friction. This paper also suggests an analysis result for the uncertainly of photographic observation of automobile crush measurement. These statistical distributions can help determine appropriate ranges for the input data in order to estimate the accident reconstruction uncertainty.

Virtual DressUp system by using image deformation method (이미지 변형 기법을 이용한 가상 드레스업 시스템)

  • Kim, Na-Ri;Yoon, Jong-Chul;Lee, In-Kwon
    • Journal of the Korea Computer Graphics Society
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    • v.15 no.2
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    • pp.1-8
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    • 2009
  • This paper introduces a virtual dress up system, according to user's input model and garment image. At first step, we deform the garment image by using skeleton structures and ARAP method. Next step, sampling the boundary points and find their matching vertices which are used for optimizing the boundary fitting. In 2D rendering of the dress up, they have some unrealistic results, so we reconstruct the garment mesh to the 3D mesh. Rendering from the reconstructed 3D mesh, we can get the final dress up result. We present that our system produce a visually plausible and well-fitted virtual dress up results.

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Flattening Class Hierarchy for Reorganization of Object-Oriented Software (객체지향 소프트웨어의 재구성을 위한 클래스계층 구조의 평탄화)

  • Hwang, Seok-Hyeong;Yang, Hae-Sul;Park, Jeong-Ho
    • The KIPS Transactions:PartD
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    • v.8D no.6
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    • pp.853-860
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    • 2001
  • In the object-oriented software development, redesigning of classes and reorganizing of class hierarchy structures should be necessary to reduce many of the headaches of object-oriented software design and maintenance. To support this task, in this paper, we propose a theoretical foundation for class hierarchy reorganizations that is relatively complete, correct, formal and easy to understand and use. We introduce the flattened class hierarchy that characterizes the class hierarchy structures in object-oriented software evolution. And we also present an algorithm which transforms a given class hierarchy into the normalized form. The flattened class hierarchy helps us map the inheritance and aggregation paths in a class hierarchy to paths in an object hierarchy that is an instance of the class hierarchy. By applying the algorithm into a given class hierarchy, we can make a new, object-preserved, and flattened class hierarchy that is the cornerstone for reorganization of class hierarchy structure and plays an important role as a bridge on the incremental evolutionary changes and reuse of object-oriented software to reorganize class hierarchies.

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