• Title/Summary/Keyword: Phase reconstruction

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A multi-institutional analysis of sternoclavicular joint coverage following osteomyelitis

  • Othman, Sammy;Elfanagely, Omar;Azoury, Said C.;Kozak, Geoffrey M.;Cunning, Jessica;Rios-Diaz, Arturo J.;Palvannan, Prashanth;Greaney, Patrick;Jenkins, Matthew P.;Jarrar, Doraid;Kovach, Stephen J.;Fischer, John P.
    • Archives of Plastic Surgery
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    • v.47 no.5
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    • pp.460-466
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    • 2020
  • Background Sternoclavicular joint (SCJ) osteomyelitis is a rare pathology requiring urgent intervention. Several operative approaches have been described with conflicting reports. Here, we present a multi-institutional study utilizing multiple surgical pathways for SCJ reconstruction. Methods A multi-institutional retrospective cohort study was conducted to identify patients who underwent surgical repair for sternoclavicular osteomyelitis between 2008 and 2019. Patients were stratified according to reconstruction approach: single-stage reconstruction with advancement flap and delayed-reconstruction with flap following initial debridement. Demographics, operative approach, type of reconstruction, and postoperative outcomes were analyzed. Results Thirty-two patients were identified. Mean patient age was 56.2±13.8 years and 68.8% were male. The average body mass index (BMI) was 30.0±8.8 kg/㎡. The most common infection etiologies were intravenous drug use and bacteremia (both 25%). Fourteen patients (43.8%) underwent one-stage reconstruction and 18 (56.2%) underwent delayed two-staged reconstruction. Both single and delayed-stage groups had comparable rates of reinfection (7.1% vs. 11.1%, respectively), surgical site complications (21.4% vs. 27.8%), readmissions (7.1% vs. 16.6%), and reoperations (7.1% vs. 5.6%; all P>0.05). The single-stage reconstruction group had a significantly lower BMI (26.2±5.7 kg/㎡ vs. 32.9±9.1 kg/㎡; P<0.05) and trended towards shorter hospital length of stay (11.3 days vs. 17.9 days; P=0.01). Conclusions Both single and delayed-stage approaches are appropriate methods with comparable outcomes for reconstruction for SCJ osteomyelitis. When clinically indicated, a single-stage reconstruction approach may be preferable in order to avoid a second operation as associated with the delayed phase, and possibly shortening total hospital length of stay.

IMPROVEMENT OF A SEMI-IMPLICIT TWO-PHASE FLOW SOLVER ON UNSTRUCTURED MESHES (비정렬 격자계에서의 물-기체 2상 유동해석코드 수치 기법 개선)

  • Lee, H.D.;Jeong, J.J.;Cho, H.K.;Kwon, O.J.
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.380-388
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    • 2010
  • A thermal-hydraulic code, named CUPID, has been developed for the analysis of transient two-phase flows in nuclear reactor components. A two-fluid three-field model was used for steam-water two-phase flows. To obtain numerical solutions, the finite volume method was applied over unstructured cell-centered meshes. In steam-water two-phase flows, a phase change, i.e., evaporation of condensation, results in a great change in the flow field because of substantial density difference between liquid and vapor phases. Thus, two-phase flows are very sensitive to the local pressure that determines the phase change. This in turn puts emphasis on the accurate evaluation of local pressure gradient. This paper presents a new numerical scheme to evaluate the pressure gradient at cell centers on unstructured meshes. The results of the new scheme for a simple test function a gravity-driven cavity, and a wall boiling two-phase flow are compared with those of the previous schemes in the cupid code.

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Utility of Gait Analysis and Functional Assessment of Prosthetic Reconstruction in Bone Tumor around the Knee (슬관절 주위에 발생한 골종양 환자에서 종양 대치물을 이용한 재건술 후 기능적 평가 및 보행 분석의 유용성)

  • Lee, Jin-Ho;Seol, Young-Jun;Jung, Sung-Taek
    • The Journal of the Korean bone and joint tumor society
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    • v.18 no.2
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    • pp.51-58
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    • 2012
  • Purpose: This study attempts to know functional results and gait analysis usefulness in patients with bone tumor around knee joint tumors who underwent prosthesis knee joint reconstruction. Materials and Methods: Retrospective study was conducted with 7 patients out of 30 patients who underwent prosthesis knee joint reconstruction after wide marginal excision for bone tumor around knee in orthopedics of this hospital from 2001 to 2010. Functional assessment and gait analysis were perforemed. Results: For the SF-36 score, while 'role physical' and 'role emotional' items showed 100% (100 points) high scores individually, general health, physical function, vitality, and social function showed low scores. The mean score of MSTS was 88.1% (23.8 points [17-27]), indicating a relatively high score. For the gait analysis, mean gait velocity was 97.2 m/s, mean cadence was 105.6 step/min, mean stride length was 111.3 m, mean step length was 61.5 cm, swing phase was 39.8%cycle, stance phase was 60.1%cycle, mean single limb support was 37.1%cycle, mean double limb support was 13.0%cycle, and mean push off was 60.7%cycle. Conclusion: It is expected that prosthesis reconstruction after wide marginal excision for bone tumor around knee has relatively good functional results. Gait analysis was considered one of method which showed gait phase and assessed functional ability objectively by quantitative assessment post operative patient condition. It might help treatment and post operative rehabilitation planning with the functional assessment.

ELECTRICAL RESISTANCE IMAGING OF TWO-PHASE FLOW WITH A MESH GROUPING TECHNIQUE BASED ON PARTICLE SWARM OPTIMIZATION

  • Lee, Bo An;Kim, Bong Seok;Ko, Min Seok;Kim, Kyung Youn;Kim, Sin
    • Nuclear Engineering and Technology
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    • v.46 no.1
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    • pp.109-116
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    • 2014
  • An electrical resistance tomography (ERT) technique combining the particle swarm optimization (PSO) algorithm with the Gauss-Newton method is applied to the visualization of two-phase flows. In the ERT, the electrical conductivity distribution, namely the conductivity values of pixels (numerical meshes) comprising the domain in the context of a numerical image reconstruction algorithm, is estimated with the known injected currents through the electrodes attached on the domain boundary and the measured potentials on those electrodes. In spite of many favorable characteristics of ERT such as no radiation, low cost, and high temporal resolution compared to other tomography techniques, one of the major drawbacks of ERT is low spatial resolution due to the inherent ill-posedness of conventional image reconstruction algorithms. In fact, the number of known data is much less than that of the unknowns (meshes). Recalling that binary mixtures like two-phase flows consist of only two substances with distinct electrical conductivities, this work adopts the PSO algorithm for mesh grouping to reduce the number of unknowns. In order to verify the enhanced performance of the proposed method, several numerical tests are performed. The comparison between the proposed algorithm and conventional Gauss-Newton method shows significant improvements in the quality of reconstructed images.

A Study on Obstacle Reasons of BIM in Construction Phase (시공단계에서의 BIM 도입 저해요인에 관한 기초연구)

  • Kim, Ji-Sun;Yoo, Seung-Kyu;Kim, Ju-Hyung;Kim, Jae-Jun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.11a
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    • pp.61-62
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    • 2011
  • Construction plans for large construction projects are problems such as Incompatibility of information, omissions due to technical limitations of 2D CAD. In addition to, Plan established for the validation such as process, cost and construction technology plan is difficult. By occurring Frequent changes in the course of business, Inefficiency of management has occurred. In the construction process, there is occurred costs and construction delays due to reconstruction or communication error. In this study, It was deemed BIM will complement Existing 2D CAD problem. And, BIM case studies in the construction phase of domestic construction were analyzed, How to apply BIM in the construction phase investigated.

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Surface Form Measurement Using Single Shot Off-axis Fizeau Interferometry

  • Abdelsalam, Dahi Ghareab;Baek, Byung-Joon;Cho, Yong-Jai;Kim, Dae-Suk
    • Journal of the Optical Society of Korea
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    • v.14 no.4
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    • pp.409-414
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    • 2010
  • This paper describes the surface form measurement of a spherical smooth surface by using single shot off-axis Fizeau interferometry. The demodulated phase map is obtained and unwrapped to remove the $2\pi$ ambiguity. The unwrapped phase map is converted to height and the 3D surface height of the surface object is reconstructed. The results extracted from the single shot off-axis geometry are compared with the results extracted from four-frame phase shifting in-line interferometry, and the results are in excellent agreement.

Optical Encryption System using a Computer Generated Hologram

  • Kim, Jong-Yun;Park, Se-Joon;Kim, Soo-Joong;Doh, Yang-Hoi;Kim, Cheol-Su
    • Journal of the Optical Society of Korea
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    • v.4 no.1
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    • pp.19-22
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    • 2000
  • A new image encoding and identification scheme is proposed for security verification by us-ing a CGH(computer generated hologram), random phase mask, and a correlation technique. The encrypted image, which is attached to the security product, is made by multiplying a QP- CGH(quadratic phase CGI) with a random phase function. The random phase function plays a key role when the encrypted image is decrypted. The encrypted image can be optically recovered by a 2-f imaging system and automatically verified for personal identification by a 4-f correlation system. Simulation results show the proposed method can be used for both the reconstruction of an original image and the recognition of an encrypted image.