• Title/Summary/Keyword: Model Reconstruction

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Image-Based Approach for Modeling 3D Shapes with Curved Surfaces (곡면을 포함하는 형상의 영상을 이용한 모델링)

  • Lee, Man-Hee;Park, In-Kyu
    • Journal of KIISE:Computer Systems and Theory
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    • v.34 no.1
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    • pp.38-48
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    • 2007
  • In this paper, we propose an image-based method for modeling 3D objects with curved surfaces based on the NURBS (Non-Uniform Rational B-Splines) representation. Starting from a few calibrated images, the user specifies the corresponding curves by means of an interactive user interface. Then, the 3D curves are reconstructed using stereo reconstruction. In order to fit the curves easily using the interactive user interface, NURBS curves and surfaces are employed. The proposed surface modeling techniques include surface building methods such as bilinear surfaces, ruled surfaces, generalized cylinders, and surfaces of revolution. In addition to these methods, we also propose various advanced surface modeling techniques, including skinned surfaces, swept surfaces, and boundary patches. Based on these surface modeling techniques, it is possible to build various types of 3D shape models with textured curved surfaces without much effort. Also, it is possible to reconstruct more realistic surfaces by using proposed view-dependent texture acquisition algorithm. Constructed 3D shape model with curves and curved surfaces can be exported in VRML format, making it possible to be used in different 3D graphics softwares.

Volume Reconstruction by Cellboundary Representation for Medical Volume Visualization (의료영상 가시화를 위한 셀 경계 방식 체적 재구성 방법)

  • Choi, Young-Kyu;Lee, Ee-Taek
    • Journal of KIISE:Computer Systems and Theory
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    • v.27 no.3
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    • pp.235-244
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    • 2000
  • This paper addresses a new method for constructing surface representation of 3D structures from a sequence of tomographic cross-sectional images, Firstly, we propose cell-boundary representation by transforming the cuberille space into cell space. A cell-boundary representation consists of a set of boundary cells with their 1-voxel configurations, and can compactly describe binary volumetric data. Secondly, to produce external surface from the cell-boundary representation, we define 19 modeling primitives (MP) including volumetric, planar and linear groups. Surface polygons are created from those modeling primitives using a simple table look-up operation. Comparing with previous method such as Marching Cube or PVP algorithm, our method is robust and does not make any crack in resulting surface model. Hardware implementation is expected to be easy because our algorithm is simple(scan-line), efficient and guarantees data locality in computation time.

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A Study on Analysis of Teachers' Recognition on Field Practice and Effectiveness of Creativity and Character Education (창의·인성교육의 현장 실천도 및 효과성에 관한 교사들의 인식 분석)

  • Won, Hyo-Heon;Park, So-Young;Im, Sung-Min;Oh, Jung-Sook;Park, Jong-Un;Kang, Beo-Deul
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.5
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    • pp.1096-1107
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    • 2014
  • The purpose of this study was to investigate teachers' recognition on field practice and effectiveness of creativity and character education. This study used post tests to examine the effects of teacher training for creativity and character education on 451 teachers. The results were as follows. Firstly, the average in satisfaction of teacher training for creativity and character education was 4.65 for elementary teachers and 4.35 for secondary teachers in summer, and 4.55 for elementary teachers and 4.42 for secondary teachers in winter. Secondly, effectiveness of teacher training on creativity and character education was showed highly as more than 4.0 and was higher in winter than in summer. Thirdly, in the case of field practice and effectiveness of teacher training for creativity and character education, the average of elementary teachers(3,66) was higher in respect of educational environment than that of secondary teachers(3.20) and the averages of elementary teachers and secondary teachers were 3.85 and 3.42 in respect of subject activity, respectively. In practising creativity and character education, it was analyzed that both elementary(ave. 3.89) and secondary(ave. 3.84) teachers went through some difficulties for curriculum reconstruction, development of instructional model, program development, and human and physical supports.

Factors Influencing Changes in Quality of Life in Patients undergoing Hematopoietic Stem Cell Transplantation: A Longitudinal and Multilevel Analysis (다층모형을 적용한 조혈모세포이식 환자의 삶의 질 변화 영향요인)

  • Song, Chi Eun;So, Hyang Sook
    • Journal of Korean Academy of Nursing
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    • v.45 no.5
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    • pp.694-703
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    • 2015
  • Purpose: This study was a prospective longitudinal study to identify changes in quality of life in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). It was based on Roy's adaptation model. Methods: The questionnaires were administered before HSCT, 30 and 100 days after HSCT. Of the 48 potentially eligible patients, 44 (91.7%) participated in the study and 40 (90.9%) completed the questionnaires at 100 days after HSCT. Multilevel analysis was applied to analyze changes in quality of life. Results: Overall, quality of life showed a decreasing tendency from pre-HSCT to 100 days after HSCT. The adaptation level of participants was compensatory. Type of conditioning was the significant factor influencing quality of life before HSCT (${\beta}_{00}$=79.92, p <.001; ${\beta}_{01}$= - 12.64, p <.001) and the change rate of quality of life (${\beta}_{10}$= - 1.66, p =.020; ${\beta}_{11}$=2.88, p =.014). Symptom severity (${\beta}_{20}$= - 1.81, p =.004), depression (${\beta}_{30}$= - 0.58, p =.001), social dependency (${\beta}_{40}$= - 0.35, p =.165), and loneliness (${\beta}_{50}$= - 0.23, p =.065) had a negative effect on changes in quality of life. Symptom severity and depression were statistically significant factors influencing changes in quality of life. Conclusion: According to the results of this study, the development of nursing intervention is needed to improve quality of life in patients undergoing allogeneic hematopoietic stem cell transplantation in the early immune reconstruction period. The interventions should include programs to enhance coping capacity and programs to help control symptom severity and depression. Also these interventions need to be started from the beginning of HSCT and a multidisciplinary approach would be helpful.

Establishment of Quick Model for Private Consumption Symptom (민간소비 이상징후에 대한 속보성 모형 구축)

  • Ahn, Sung-Hee;Lee, Zoonky;Ha, Ji-Eun
    • The Journal of Bigdata
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    • v.2 no.1
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    • pp.59-69
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    • 2017
  • According to precedent research of disaster economics, most of the studies are either based on belated macroeconomic indicators or are limited to specific industries. It is certain that preventing disaster is important, but immediate analysis and reconstruction policy are crucial as well. This research analyzed the ripple effect of consumer spending followed by April 16 ferry disaster and MERS outbreak; it was done by applying credit card company's real-time big data with Marketing Mix Modeling. The main focus of this research is to see if it is possible to predict the scale of damage during ongoing disasters. It is found that setting up weekly MMM and moving the timeline draws significance conclusion. When disasters or events occur in future, this research may be the basis of building quick and intuitive indicator to monitor possible effects.

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Hinge rotation of a morphing rib using FBG strain sensors

  • Ciminello, Monica;Ameduri, Salvatore;Concilio, Antonio;Flauto, Domenico;Mennella, Fabio
    • Smart Structures and Systems
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    • v.15 no.6
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    • pp.1393-1410
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    • 2015
  • An original sensor system based on Fiber Bragg Gratings (FBG) for the strain monitoring of an adaptive wing element is presented in this paper. One of the main aims of the SARISTU project is in fact to measure the shape of a deformable wing for performance optimization. In detail, an Adaptive Trailing Edge (ATE) is monitored chord- and span-wise in order to estimate the deviation between the actual and the desired shape and, then, to allow attaining a prediction of the real aerodynamic behavior with respect to the expected one. The integration of a sensor system is not trivial: it has to fit inside the available room and to comply with the primary issue of the FBG protection. Moreover, dealing with morphing structures, large deformations are expected and a certain modulation is necessary to keep the measured strain inside the permissible measure range. In what follows, the mathematical model of an original FBG-based structural sensor system is presented, designed to evaluate the chord-wise strain of an Adaptive Trailing Edge device. Numerical and experimental results are compared, using a proof-of-concept setup. Further investigations aimed at improving the sensor capabilities, were finally addressed. The elasticity of the sensor structure was exploited to enlarge both the measurement and the linearity range. An optimisation process was then implemented to find out an optimal thickness distribution of the sensor system in order to alleviate the strain level within the referred component.

Animal Experiments of Heart Transplantation for Complicated Congenital Heart Disease in Neonate (신생아의 복잡심장기형에서 심장이식을 위한 동물실험)

  • 박영환;윤치순;정원석;김명옥;조범구
    • Journal of Chest Surgery
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    • v.32 no.6
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    • pp.504-509
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    • 1999
  • Background: Heart transplantation is considerated for a selected certain group of complicated congenital heart disease in neonates because corrective surgery is very difficult and has high mortality. Precise planning of transplantation is necessary to adequately fit the donor heart to the recipient. Material and Method: We have performed 4 neonatal pig heart transplantations to test the technical feasibility. Experiment 1: The transplantation was performed using the same technique as the adult heart transplantation. Experiment 2: The transplantation for hypoplastic left heart syndrome was simulated as we reconstructed the whole aortic arch with donor aorta. Experiment 3: The heart transplantation was done with radical pulmonary artery reconstruction. Experiment 4: The experiment was performed for a long term survival. Result: Preoperative planning was very important for adequate fitting. All animals could be weaned from cardiopulmonary bypass, however, two animals died due to bleeding at pulmonary artery and left atrium. Conclusion: We concluded that the neonatal heart transplantation can be applied in some complicated Further using animal model is mandatory.

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MRI Artifact Correction due to Unknown Respiratory Motion (미지 호흡운동에 의한 MRI 아티팩트의 수정)

  • 김응규
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.5
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    • pp.53-62
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    • 2004
  • In this study, an improved post-processing technique for correcting MRI artifact due to the unknown respiratory motion in the imaging plane is presented. Respiratory motion is modeled by a two-Dimensional linear expending-shrinking movement. Assuming that the body tissues are incompressible fluid like materials, the proton density per unit volume of the imaging object is kept constant. According to the introduced model, respiratory motion imposes phase error, non-uniform sampling and amplitude modulation distortions on the acquired MRI data. When the motion parameters are known or can be estimatead a reconstruction algorithm based on biliner superposition method was used to correct the MRI artifact. In the case of motion parameters are unknown, first, the spectrum shift method is applied to find the respiratory fluctuation function, x directional expansion coefficient and x directional expansion center. Next, y directional expansion coefficient and y directional expansion center are estimated by using the minimum energy method. Finally, the validity of this proposed method is shown to be effective by using the simulated motion images.

TISSUE-ENGINEERED RECONSTITUTION OF ORAL MUCOSA USING POLYDIOXANONE MESH (Polydioxanone mesh를 이용한 구강점막의 조직 공학적 재건)

  • Moon, Seon-Jae;Joo, So-Yeon;Kim, Jin;Kim, Hak-Yong;Park, Jung-Keug;Cha, In-Ho
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.29 no.4
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    • pp.249-256
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    • 2003
  • The lack of sufficient oral mucosa available for intra-oral reconstruction has been dealt with by the use of skin or oral mucosa grafts harvested from donor sites but grafts requires more than one surgical procedures and could cause donor site morbidity. Many investigators have attempted to increase available soft tissue by tissue engineered skin or oral mucosa replacements for clinical applications. But, reconstructed mucosa by several methods have low physical properties such as rolling and contraction. The aims of this study were to develope an in vitro experimental model that maintains an epithelial-mesenchymal interaction by organotypic raft culture, and to characterize biologic properties of three-dimensionally cultured oral mucosa embedded with Polydioxanone mesh by histological and immunohistochemical analysis. The results were as follows; 1. Oral mucosa reconstructed by three-dimensional organotypic culture revealed similar morphologic characteristics to equvalent normal oral mucosa in the point that they show stratification and differentiation. 2. The expression of cytokeratin 10/13 and involucrin in the cultured tissue showed the same pattern with normal oral mucosa suggesting that organotypic co-culture condition is able to induce cellular differentiation. 3. After insertion of polydioxanone mesh, increased tensile strength were observed. These results suggest that three-dimensional organotypic co-culture of the oral mucosa cell lines with the dermal equvalent consisting type I collagen and fibroblasts reproduce the morphologic and immunohistochemical characteristics similar to those in vivo condition. And increased physical properties by use of polydioxanone mesh will helpful for clinical applications.

Object Tracking in HEVC Bitstreams (HEVC 스트림 상에서의 객체 추적 방법)

  • Park, Dongmin;Lee, Dongkyu;Oh, Seoung-Jun
    • Journal of Broadcast Engineering
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    • v.20 no.3
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    • pp.449-463
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    • 2015
  • Video object tracking is important for variety of applications, such as security, video indexing and retrieval, video surveillance, communication, and compression. This paper proposes an object tracking method in HEVC bitstreams. Without pixel reconstruction, motion vector (MV) and size of prediction unit in the bitstream are employed in an Spatio-Temporal Markov Random Fields (ST-MRF) model which represents the spatial and temporal aspects of the object's motion. Coefficient-based object shape adjustment is proposed to solve the over-segmentation and the error propagation problems caused in other methods. In the experimental results, the proposed method provides on average precision of 86.4%, recall of 79.8% and F-measure of 81.1%. The proposed method achieves an F-measure improvement of up to 9% for over-segmented results in the other method even though it provides only average F-measure improvement of 0.2% with respect to the other method. The total processing time is 5.4ms per frame, allowing the algorithm to be applied in real-time applications.