• Title/Summary/Keyword: statistical reconstruction

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Clinical Results of Anatomical Single Bundle Anterior Cruciate Ligament Reconstruction Using Autogenous Quadriceps Tendon (자가 대퇴사두건을 이용한 해부학적 단일 다발 전방십자인대 재건술의 임상적 결과)

  • Park, Jin;Kim, Young Sin;Lee, Ju Hong;Wang, Seong Il;Park, Chan Ill
    • Journal of the Korean Arthroscopy Society
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    • v.16 no.1
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    • pp.26-33
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    • 2012
  • Purpose: The purpose of this study was to evaluate the clinical outcomes and stability of anatomical single bundle anterior cruciate ligament reconstruction (SBACLR) with quadriceps tendon comparable to double bundle anterior cruciate ligament reconstruction (DBACLR). Materials and Methods: We retrospectively reviewed 28 consecutive patients (16 male, 12 female) who underwent SBACLR using quadriceps tendon from March 2009 (Group 1) and compared its clinical results to whom DBACLR with semitendinosus tendon for 53 patients (51 male, 2 female) from August. 2006 (Group 2). Mean age were 34.9 (range, 16-52) in Group 1 and 21.6 (range, 17-55) in Group 2. Mean follow up periods were 13.9 months (range, 12-20) in Group 1 and 36.2 months (range, 20-52) in Group 2. Lysholm score, International Knee Documentation Committee (IKDC) evaluation form and Tegner score were performed for evaluating the clinical outcome. Lachman test, pivot shift test and KT-1000 arthrometer (MEDmetric Corp., San Diego, CA, USA) were performed for stability. Results: There was no statistical significant difference between the two groups in terms of Lysholm score (Group 1: $85.9{\pm}2.6$, Group 2: $90.9{\pm}1.0$, P=0.226), IKDC score (P=0.345) and Tegner score (Group 1: $6.9{\pm}1.4$, Group 2: $7.1{\pm}1.3$, P=0.523). Nor was there statistical significance between the two groups in terms of KT-1000 arthrometer (Group 1: $1.5{\pm}1.1\;mm$, Group 2: $1.5{\pm}1.6\;mm$, P=0.457), Lachman test (P=0.547) and pivot shift test (P=0.073). Conclusion: Anatomical SBACLR with quadriceps tendon shows similar clinical outcomes and stability comparable to anatomical DBACLR with hamstring tendon.

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Usability Evaluation of Applied Low-dose CT When Examining Urinary Calculus Using Computed Tomography (컴퓨터 단층촬영을 이용한 요로결석 검사에서 저선량 CT의 적용에 대한 유용성 평가)

  • Kim, Hyeon-Jin;Ji, Tae-Jeong
    • The Journal of the Korea Contents Association
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    • v.17 no.6
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    • pp.81-85
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    • 2017
  • The aim of this study was to evaluate the usability of applied Low dose Computed Tomography(LDCT) protocol in examining urinary calculus using computed tomography. The subjects of this study were urological patients who visited a medical institution located in Busan from June to December 2016 and the protocol used in this study was Adaptive Statistical Iterative Reconstruction: low-dose CT with 50% Adaptive Statistical Iterative Reconstruction (ASIR). As results of quantitative analysis, the mean pixel value and standard deviation within kidney region of image(ROI)of the axial image were $26.21{\pm}7.08$ in abdomen CT pre scan and $20.03{\pm}8.16$ in low-dose CT. Also the mean pixel value and standard deviation within kidney ROI of the coronal image were $22.07{\pm}7.35$ in abdomen CT pre scan and $21.67{\pm}6.11$ in low dose CT. The results of qualitative analysis showed that four raters' mean values of observed kidney artifacts were $19.14{\pm}0.36$ when using abdomen CT protocol and $19.17{\pm}0.43$ in low-dose CT, and the mean value of resolution and contrast was $19.35{\pm}0.70$ when using abdomen CT protocol and $19.29{\pm}0.58$ in low-dose CT. Also the results of a exposure dose analysis showed that the mean values of CTDIvol and DLP in abdomen CT pre scan were 18.02 mGy and $887.51mGy{\cdot}cm$ respectively and the mean values of CTDIvol and DLP when using low-dose CT protocol were 7.412 mGy and $361.22mGy{\cdot}cm$ respectively. The resulting dose reduction rate was 58.82% and 59.29%, respectively.

Reconstruction of the Volcanic Lake in Hanon Volcano Using the Spatial Statistical Techniques (공간통계기법을 이용한 하논화산의 화구호 복원)

  • Choi Kwang-Hee;Yoon Kwang-Sung;Kim Jong-Wook
    • Journal of the Korean Geographical Society
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    • v.41 no.4 s.115
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    • pp.391-403
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    • 2006
  • The Hanon volcano located in the southern pan of Cheju Island, Korea has a wetland in its crater being used as a farmland. Previous researchers presumed this wetland was a maar lake in the past. Based on the seismic refraction method, the wetland sediment layer was estimated between 5 to 14 m deep, which is mostly in accordance with previous researches. However, this shows only the depths at some sites, not representing the whole spatial distribution. This study is an attempt to reconstruct the volcanic lake in Hanon crater by applying the spatial statistical techniques based on the depth information from the seismic survey and known data. The procedure of reconstruction is as follows: First, the depth information from the seismic survey and known data were collected and it was interpolated by IDW and Ordinary Kriging method. Next, with the interpolation map and the present DEM the paleo DEM was constructed. Finally, using the paleo lake level on core data, the boundary of volcanic lake was extracted from the paleo DEM. The reconstructed lake resembles a half-moon in the north of the central scoria cone. It is estimated that the lake was 5 m deep on average and 13 m deep at the deepest point. Although there are slight differences according to the interpolation techniques, it is calculated that the area of the lake was between 184,000 and $190000m^2,$ and its volume approximately $869,760m^3$. Because of the continuous deposition processes after the crater formation, the reconstructed volcanic lake would not indicate an actual lake at a specific time. Nevertheless, it offers a significant clue regarding the inner morphology and evolution of the crater.

Short Term and Midterm Surgical Results for Infective Endocarditis - Does Wide Debridement and Reconstruction Affect the Post Operative Mortality and Morbidity? (90년대 중반 이후 시행한 감염성 심내막염의 중단기 수술 성적)

  • Yie, Kil-Soo;Oh, Sam-Sae;Kim, Jae-Hyun;Shinn, Sung-Ho;Kim, Jong-Hwan;Kim, Soo-Cheol;Na, Chan-Young
    • Journal of Chest Surgery
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    • v.40 no.5 s.274
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    • pp.341-350
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    • 2007
  • Background: We present here the early and midterm surgical results for infective endocarditis and we especially focus on the effect of aggressive reconstruction or root implantation after wide debridement. Material and Method: Between January 1995 and Jun 2006, we enrolled 79 adult infective endocarditis patients who underwent surgical treatment. There were 63 and 16 native and prosthetic valve endocarditis cases, respectively. They included 27 cases of culture negative endocarditis. With performing valve replacement or repair, 28 of the patient underwent a more aggressive surgical option, for example, aortic root replacement or reconstruction, or heart base reconstruction etc. Result: There were statistical relationships between the in-hospital mortality and staphylococcal infection, urgent-based operation and operation during the active phase of endocarditis. Wide debridement and aggressive reconstruction were not related to either the post operative mortality or the early morbidity. Culture negative endocarditis was not related to the postoperative mortality and morbidity. Conclusion: Physicians must pay attention to patients' medical treatment during the preoperative period of the infective endocarditis. If surgery is considered for treating infective endocarditis, it should be performed before the downhill course of the disease so that the surgical outcome is improved. Wide debridement and more aggressive reconstruction are also warranted.

Development of Korean Pedestrian Accident Reconstruction Model (한국형 보행자 사고재현 모형 개발에 관한 연구)

  • Lee, Su-Beom;Lui, Tae-Sun
    • Journal of Korean Society of Transportation
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    • v.23 no.6 s.84
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    • pp.103-113
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    • 2005
  • A pedestrian accident is generally less fully understood than the 'typical' car-to-car collision. For this reason, the analysis of the pedestrian accident is, in many respects, more complicated and demanding. The purpose of this study is to identify clearly the impact point that is the main subject of struggle in pedestrian accidents. In order to develop the model, it is very significant to classify actual accident data including impact velocity. vehicle damage and injury scale of pedestrian. These data were collected from three local branches of RTSA(Road Traffic Safely Authority). The number of collected data were 34 cases and 61.7% of them were fatal accidents. In consequence of analyzing the data by statistical method, it revealed that there is correlation between impact velocity and throw distance. It, also shows that the impact velocity has strong linear correlation to vehicle damage and injury scale. Consequently, reconstruction analysis models of pedestrian accidents considering in local circumstances(such as the physical characteristics of pedestrians and vehicles) was developed However. it is difficult to apply the result of this study to all sorts of pedestrian accidents, because the actual accident data which were used to develop the model were limited. To overcome this limitation, it is necessary to develop an analysis model applicable to diverse circumstances with a wide range of pedestrian accident data on a national basis.

The changes of cerebral blood flow by brain imaging algorithm in the Normal Brains : Analysis by Statistical Parametric Mapping (정상 뇌혈류 영상에서 재구성 알고리즘 적용에 따른 섭취율 차이 : 통계적 파라미터 지도를 사용한 분석)

  • Lee, Hyo-Yeong;Kim, Yun-Jin;Sin, Sung-Gyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.11
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    • pp.5311-5316
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    • 2012
  • Single Photon Emission Computed tomography(SPECT) was performed on 13 healthy adults (average age: 39) to investigate the changes of cerebral blood flow according to brain imaging analysis algorithm. The acquired images were filtered and reconstructed through Filtered Back Projection (FBP) and Ordered Subset Expectation Maximization (OSEM). The brain distribution data of radiopharmaceuticals were compared using Statistical Parametric Mapping (SPM), and the changes of blood flow was expressed in Cluster. As a result, uptake rate was increased in Sub-gyral, Sub-Lobar, Extra-Nuclear, Limbic lobe and Cingulate Gyrus, while uptake rate was decreased in Middle frontal gyrus, Inferior Frontal Gyrus and Precentral Gyrus. The discriminable SPM was shown according to cerebral blood flows in Cluster by the reconstruction algorithm.

Segmentation and estimation of surfaces from statistical probability of texture features

  • Terauchi, Mutsuhiro;Nagamachi, Mitsuo;Koji-Ito;Tsuji, Toshio
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10b
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    • pp.826-831
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    • 1988
  • This paper presents an approach to segment an image into areas of surfaces, and to compute the surface properties from a gray-scale image in order to describe the surfaces for reconstruction of the 3-D shape of the objects. In general, an rigid body has several surfaces and many edges. But if it is not polyhedoron, it is necessary not only to describe the relation between surfaces, i.e. its line drawings but also to represent the surfaces' equations itself. In order to compute the surfaces' equation we use a probability of edge distribution. At first it is extracted edges from a gray-level image as much as possible. These are not only the points that maximize the change of an image intensuty but candidates which can be seemed to be edges. Next, other character of a surface (color, coordinates and image intensity) are extracted. In our study, we call the all feature of a surface as "texture", for example color, intensity level, orientation of an edge, shape of a surface and so on. These features of a surface on a pixel of an image plane are mapped to a point of the feature space, and segmented to each groups by cluster analysis on this space. These groups are considered to represent object surface in an image plane. Finally, the states of object surface in 3-D space are computed from distributional probability of local and overall statistical features of a surface, and from shape of a surface.a surface.

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THE ADAPTATION METHOD IN THE MONTE CARLO SIMULATION FOR COMPUTED TOMOGRAPHY

  • LEE, HYOUNGGUN;YOON, CHANGYEON;CHO, SEUNGRYONG;PARK, SUNG HO;LEE, WONHO
    • Nuclear Engineering and Technology
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    • v.47 no.4
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    • pp.472-478
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    • 2015
  • The patient dose incurred from diagnostic procedures during advanced radiotherapy has become an important issue. Many researchers in medical physics are using computational simulations to calculate complex parameters in experiments. However, extended computation times make it difficult for personal computers to run the conventional Monte Carlo method to simulate radiological images with high-flux photons such as images produced by computed tomography (CT). To minimize the computation time without degrading imaging quality, we applied a deterministic adaptation to the Monte Carlo calculation and verified its effectiveness by simulating CT image reconstruction for an image evaluation phantom (Catphan; Phantom Laboratory, New York NY, USA) and a human-like voxel phantom (KTMAN-2) (Los Alamos National Laboratory, Los Alamos, NM, USA). For the deterministic adaptation, the relationship between iteration numbers and the simulations was estimated and the option to simulate scattered radiation was evaluated. The processing times of simulations using the adaptive method were at least 500 times faster than those using a conventional statistical process. In addition, compared with the conventional statistical method, the adaptive method provided images that were more similar to the experimental images, which proved that the adaptive method was highly effective for a simulation that requires a large number of iterations-assuming no radiation scattering in the vicinity of detectors minimized artifacts in the reconstructed image.

Management of Defects on Lower Extremities with the Use of Matriderm and Skin Graft

  • Choi, Jun-Young;Kim, Seong-Hun;Oh, Gwang-Jin;Roh, Si-Gyun;Lee, Nae-Ho;Yang, Kyung-Moo
    • Archives of Plastic Surgery
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    • v.41 no.4
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    • pp.337-343
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    • 2014
  • Background The reconstruction of large skin and soft tissue defects on the lower extremities is challenging. The skin graft is a simple and frequently used method for covering a skin defect. However, poor skin quality and architecture are well-known problems that lead to scar contracture. The collagen-elastin matrix, Matriderm, has been used to improve the quality of skin grafts; however, no statistical and objective review of the results has been reported. Methods Thirty-four patients (23 male and 11 female) who previously received a skin graft and simultaneous application of Matriderm between January 2010 and June 2012 were included in this study. The quality of the skin graft was evaluated using Cutometer, occasionally accompanied by pathologic findings. Results All 34 patients showed good skin quality compared to a traditional skin graft and were satisfied with their results. The statistical data for the measurement of the mechanical properties of the skin were similar to those for normal skin. In addition, there was no change in the engraftment rate. Conclusions The biggest problem of a traditional skin graft is scar contracture. However, the dermal matrix presents an improvement in skin quality with elastin and collagen. Therefore, a skin graft along with a simultaneous application of Matriderm is safe and effective and leads to a significantly better outcome from the perspective of skin elasticity.

Missing Value Estimation and Sensor Fault Identification using Multivariate Statistical Analysis (다변량 통계 분석을 이용한 결측 데이터의 예측과 센서이상 확인)

  • Lee, Changkyu;Lee, In-Beum
    • Korean Chemical Engineering Research
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    • v.45 no.1
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    • pp.87-92
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    • 2007
  • Recently, developments of process monitoring system in order to detect and diagnose process abnormalities has got the spotlight in process systems engineering. Normal data obtained from processes provide available information of process characteristics to be used for modeling, monitoring, and control. Since modern chemical and environmental processes have high dimensionality, strong correlation, severe dynamics and nonlinearity, it is not easy to analyze a process through model-based approach. To overcome limitations of model-based approach, lots of system engineers and academic researchers have focused on statistical approach combined with multivariable analysis such as principal component analysis (PCA), partial least squares (PLS), and so on. Several multivariate analysis methods have been modified to apply it to a chemical process with specific characteristics such as dynamics, nonlinearity, and so on.This paper discusses about missing value estimation and sensor fault identification based on process variable reconstruction using dynamic PCA and canonical variate analysis.