• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.6
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• pp.59-66
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• 2013

Spray characteristics of single round jet with liquid nitrogen and coaxial spray with liquid nitrogen and gaseous argon were observed. Shadowgraph method was used for spray visualization, and density gradient magnitude image was used to analyse the result. In subcritical condition, irregularity of the jet surface was harder in the coaxial spray. In supercritical condition, diffusion of nitrogen injected from shear coaxial injector was faster than single jet. Jet diameter was induced by averaging images, in supercritical condition, difference of diameter of coaxial jet was rapidly decreased than that of single jet.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.2 s.314
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• pp.144-152
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• 2007

We propose a 3D modeling method for surface inspection of non-linear moving object. The laser lines reflect the surface curvature. We can acquire 3D surface information by analyzing projected laser lines on object. ill this paper, we use multi-line laser to make use of robust of single stripe method and high speed of single frame. Binarization and channel edge extraction method were used for robust laser line extraction. A new labeling method was used for laser line labeling. We acquired sink information between each 3D reconstructed frame by feature point matching, and registered each frame to one whole image. We verified the superiority of proposed method by applying it to container damage inspection system.

• Journal of the Institute of Convergence Signal Processing
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• v.8 no.1
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• pp.15-21
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• 2007

We propose a 3D modeling method for surface inspection of non-constant velocity moving object. 1'lie laser lines reflect tile surface curvature. We can acquire 3D surface information by analyzing projected laser lines on object. In this paper, we use multi-line laser to improve the single stripe method and high speed of single frame. Binarization and edge extraction of frame image were proposed for robust laser each line extraction. A new labeling method was used for laser line labeling. We acquired some feature points for image matching from the frame data and juxtaposed the frames data to obtain a 3D shape image. We verified the superiority of proposed method by applying it to inspect container's damages.

• The Journal of Korean Academy of Sensory Integration
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• v.20 no.3
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• pp.1-13
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• 2022

Objective : The purpose of this study was to investigate changes in somato-sensory and occupational performance of individually tailored sensory integration interventions for school-age children with somatodyspraxia. Methods : A single subject study with an AB design was conducted the total sessions were 11 sessions, consisting of 3 baseline sessions and 8 intervention sessions. To compare the effects before and after the intervention, the intervention was measured by dividing it into Performance Area (PA) and Performance Factor (PF), and after each intervention session, the Goal Attainment Scale (GAS) was implemented. Results : The children participating in this study showed overall improvement in PA and PF after the intervention, and after each session, it was confirmed that the GAS increased when measuring the target activities (Supine Flexion Posture; SFP, Walking by Arms; WA, Stand on Balance Ball; SBB). Conclusion : This study provided evidence that sensory integration has a positive effect on performing target activities (SFP, WA, SBB) and improving relationships with peers in children with somatodyspraxia.

• Polymer(Korea)
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• v.26 no.1
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• pp.139-144
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• 2002

In this study, the PPS/ABS blend system was investigated in order to identify the relationship between the incorporation of compatabilizing moieties and the mechanical properties. ABS resin was chemically modified by the incorporation of maleic anhydride using reactive extrusion method to yield MABS resin, and PPS/MABS blend was prepared by a twin screw extruder. Single glass transition behavior was observed in the various compositions of PPS/MABS blend by dynamic mechanical analysis study. Upon the examination of the mechanical properties, the PPS/MABS blend exhibited an enhanced tensile, flexural and impact strength, which might be due to the better chemical compatibilization to result in the reduced interfacial tension between each components.

• Journal of the Korean Arthroscopy Society
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• v.12 no.3
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• pp.198-204
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• 2008

Purpose: The purpose of this study is to analyze the merits and demerits of double bundle reconstruction and achieve improvements hereafter, by comparing the results of double bundle and single bundle reconstruction using tibialis anterior allograft. Materials and Methods: Twenty seven patients were divided to undergo either double bundle(n=14) or single bundle(n=13) reconstruction with tibialis anterior allograft tendon. The evaluation methods were AP laxity with KT-2000 arthrometer, isokinetic knee strength measurements, pivot-shift test, IKDC subjective score, Lysholm knee score, Tegner activity score, radiographic evaluations with postoperative MRI, and second look arthroscopy. Results: Lysholm knee score and Tegner activity score were significantly better in double bundle reconstruction. In pivot-shift test, single bundle reconstruction was evaluated as grade 0 in 10 of the knees, grade 1 in 1, and grade 2 in 2. Double bundle reconstruction was evaluated as grade 0 in 13, and grade 2 in 1. In second look arthroscopy, single bundle was evaluated as excellent in 6 of the knees, fair in 7, anteromedial bundle of double bundle reconstruction was excellent in 13 and fair in 1, and posterolateral bundle was excellent in 4, fair in 9, and poor in 1. There were no significant differences in other evaluations. Conclusion: Favorable outcome may be expected with double bundle reconstruction of ACL. However there are still need for improvement in terms of reconstruction technique and rehabilitation protocol to reduce PL bundle injury.

• Journal of the Korean Arthroscopy Society
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• v.16 no.2
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• pp.107-113
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• 2012

Purpose: The purpose of this study was to evaluate the posterior cruciate ligament (PCL) reconstruction with single bundle, single-incision technique using Achilles tendon and tibialis anterior allograft with ligament remnant preservation. Materials and Methods: Twenty six patients underwent PCL reconstruction was included. There were 21 males and 5 females. Mean age was 32 years. Used graft was a fresh frozen Achilles tendon allograft (group I, 14 cases) and tibialis anterior allograft (group II, 12 cases). Arthroscopic PCL reconstruction was performed using transtibial, single-incision and single bundle technique with remnant preserving as possible. For clinical evaluation, range of motion, posterior drawer test, Lysholm score, Tegner activity scale, International Knee Documentation Committee (IKDC) grade and posterior stress radiograph were used. The mean follow-up period was 21.6 months (12-40 months). Associated injuries were 5 medial collateral ligament injuries, which were treated by conservative method. Results: Range of motion (ROM) was returned to normal range in 24 cases, but ROM deficit under $10^{\circ}$ flexion was 2 cases at final follow-up period. Preoperative posterior drawer test was 17 cases in grade II and 9 cases in grade III. At final follow-up 13 cases returned within normal grade, 7 cases grade I and 6 cases grade II posterior instability. Lysholm mean score was improved from preoperatively 62 to 90 at final follow-up period. Tegner activity mean scale improved from preoperatively 3.5 to 5.6 at final follow-up period. IDKC grade was grade A was 3 cases, grade B 17 cases, grade C 6 cases. In posterior stress radiograph, posterior displacement was improved from mean 12 mm preoperative to 4.5 mm at final follow-up. There were no statistical differences between two groups in clinical evaluations. There were two cases of re-rupture of graft at the bone-tendon junction in group I. Conclusion: We had successful results of PCL reconstruction with single-incision, single bundle technique using Achilles and tibialis anterior allograft without difference between two groups in patients with PCL injury. There were more re-rupture of graft in Achilles tendon group.

• Tuberculosis and Respiratory Diseases
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• v.53 no.3
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• pp.285-293
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• 2002

Background : The lung is the most common site for a metastasis of extrapulmonary malignant tumors. however, reports on an endobronchial metastasis are rare. An endobronchial metastasis is defined as a documented extrapulmonary neoplasms metastatic to the segmental or more proximal central bronchus within a bronchoscopically visible range. The purpose of this study was to define the clinical characteristics of an endobronchial metastasis of extrapulmonary malignancies. Materials and Methods : The clinical features and treatment outcomes of 27 endobronchial metastatic cancer cases were reviewed from June, 1991 to May, 2001 in the Severance Hospital. Results : The patients' age ranged from 18 to 75. There were 17 men and 10 women. The primary tumors included the colorectum in 7, the uterine cervix in 4, the stomach and the breast in 3 patients each, and an osteosarcoma in 2 patients. The main complaint of most patients was coughing and a chest X-ray revealed a hilar mass, a parenchymal, and an atelectasis. The mean recurrence interval time was 45.5 months. The median and mean survival times were 10 and 12.3 months, respectively. Conclusion : An endobronchial metastasis is an ominous finding, and is associated with advanced-stage diseases. It requires differential diagnosis with a primary bronchogenic carcinoma. If atypical clinical features are present or an atypical cell type is discovered by a biopsy of the lesion in the lung mass, the appropriate diagnostic studies should be undertaken.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6C
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• pp.267-274
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• 2012

The conventional approach to evaluate the contaminant transport in soils adopts the macro-scale implementation while the pore configuration and network is a dominant factor to determine the fate of contaminant. However, the observation of fate and transport at pore scale may not be readily approachable because of the computational expenses to solve Navier-Stokes equation. We herein present the 2D Lattice-Boltzmann method that enables to assess the local fluid velocity and density efficiently for the case of single phase and multi-components. The solute fate spatio-temperal space is explicitly determined by the advection of fluid flow. Two different types of idealized pore space provides the path of fluid. Also, solute transport, the velocity field and average concentration of solute are computed in steady state. Results show that the pore geometry such as tortuosity mainly affect the solute fate. It highlights the significance of the pore configuration and shape in granular soils and rock discontinuity in spite of the equivalent porosity.

• Applied Chemistry for Engineering
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• v.26 no.4
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• pp.406-412
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• 2015

Unidirectional carbon/carbon (C/C) composites were manufactured using phenolic resins as a precursor of the carbonized matrix throughout a one-step manufacturing process. Also, molybdenum oxide ($MoO_3$) and binder pitches were impregnated with phenolic resins to improve the bulk density and mechanical property of the C/C composites. In this study, the influence of $MoO_3$ and binder pitches on mechanical properties of the C/C composites were investigated by measuring flexural strength (${\sigma}_f$) and interlaminar shear strength (ILSS). The results show that the enhancement of interfacial adhesions between the fibers and matrix resins of the C/C composites with $MoO_3$ and binder pitches which led to the improvement of mechanical properties of the C/C composites. This indicates that the presence of $MoO_3$ and binder pitches in C/C composites can develop the graphite structure and increase the bulk density.