• Journal of Veterinary Clinics
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• v.29 no.6
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• pp.498-501
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• 2012

A 10-month-old intact male Maltese dog (body weight, 1.6 kg) presented with intermittent cough and abnormal heart sounds. The dog was diagnosed with a left-to-right patent ductus arteriosus (PDA) on the basis of the results of transthoracic echocardiography, color flow Doppler examination, and angiography. Transcatheter occlusion of the PDA was performed using the $Amplatz^{(R)}$ Canine Duct Occluder (ACDO) via the femoral artery. The device was placed under fluoroscopic guidance and successfully occluded the PDA. The continuous heart murmur disappeared immediately after the correction and no residual flow was detected. The dog was discharged the following day and regularly examined for complications and safety. This is the first report demonstrating the clinical application of ACDO for the transcatheter closure of PDA via the femoral artery in a small-breed dog in Korea.

• Speech Sciences
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• v.5 no.1
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• pp.121-139
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• 1999

Our experimental subject was a laryngectomee who had undergone total laryngectomy with $PROVOX^{(R)}$ insertion, and learned esophageal speech after the surgery, so he could produce both $PROVOX^{(R)}$ voice and esophageal voice. With this subject's production of $PROVOX^{(R)}$ and esophageal voice, we are to compare the acoustic and aerodynamic characteristics of the two voices, under the same physical conditions of the same person. As a result, the fundamental frequency of esophageal voice was 137.2 Hz, and that of $PROVOX^{(R)}$ was 97.5 Hz. $PROVOX^{(R)}$ voice showed lower jitter, shimmer and NHR than esophageal voice, which means that $PROVOX^{(R)}$ voice showed better voice quality than esophageal voice. In spectrographic analysis, the formation of formants and pseudoformants were more distinct in esophageal voice and several temporal aspects of acoutic features such as VOT and closure duration were more similar with normal voice in $PROVOX^{(R)}$ voice. During the sentence utterance, esophageal voice showed longer pause or silence duration than $PROVOX^{(R)}$ voice. Maximum phonation time and mean flow rate of $PROVOX^{(R)}$ voice were much longer and larger than esophageal voice, but mean and range of sound pressure level, subglottic pressure and voice efficiency were similar in the two voices. Glottal resistance of esophageal voice was much larger than $PROVOX^{(R)}$ voice which showed still larger glottal resistance than normal voice.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.4
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• pp.80-88
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• 1997

An experimental investigation of the fatigue through crack growth behavior under simple stepped variable loading condition has been performed using Al7075-T651. Experiments were carried out by using cantilever bending type specimens, with chevron notches on a small electro-magnetic test machine. Tensile overloads have a retarding effect on the fatigue crack growth rates, therefore tensile overloads were used for the beneficial effect on the fatigue life. While in most cases compressive overloads have only a vanishing effect on crack growth rates, some experiments with single edge crack tension specimens reveal a marked growth retardation. The stress ratios used in this investigations varies from R=0.32 to 0.81, from R=0.04 to 0.76, from R=-0.15 to 0.73, and from R=-0.33 to 0.68 and the peak load for each case was not varied. The crack growth and crack closure were measured by Kikukawa's compliance method with a strain gauge mounted on the backside of each specimens. The results obtained are as follows. When the stepped variable load was applied, the smaller the stress ration was, the larger the delayed retardation of the crack growth rate was. The fatigue crack growh rate data obtained for through cracks were plotted well against the effective stress intensity factor range from 4.0 to 20.0MP{a^{SQRT}m}. It was found that the effective stress intensity factor range ratio was related well to the opening stress intensity factor, the maximum stress intensity factor, and crack length.

• Journal of Korean Neurosurgical Society
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• v.53 no.5
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• pp.300-302
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• 2013

Reports of traumatic leptomeningeal cysts (TLMC) are rare in adults. The standard treatment approach is craniectomy with careful exposure of the intact dural edges, followed by duroplasty. However, occasionally, the location of the TLMC makes achieving watertight duroplasty impossible. Herein, we report the case of a 28-year-old male who presented with a soft growing mass on the vertex of his head 16 months after the head trauma. Upon enhanced CT examination, a bony defect involving both the inner and outer table of the cranium was observed close to the sagittal sinus, and a well-defined cystic mass, 5 cm in diameter, was nested within the defect. The risks associated with extension craniotomy were high because the lesion was located superficial to the sagittal sinus, we opted to use fibrinogen-based collagen fleece (TachoCombR$^{(R)}$) to repair the dural defect. Two months after surgery, the patient remained asymptomatic with a good cosmetic result. In cases like ours, when the defect is near the major sinuses and the risk of rupturing the sinus during watertight dural closure is high, fibrinogen-based collagen fleece (TachoCombR$^{(R)}$) is an effective alternative approach to standard dural suture techniques.

• Nuclear Engineering and Technology
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• v.37 no.6
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• pp.511-524
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• 2005

Thermalhydraulic reactor simulation of tomorrow will require a new generation of codes combining at least three scales, the CFD scale in open medium, the component scale and the system scale. DNS will be used as a support for modelling more macroscopic models. NEPTUNE is such a new generation multi-scale platform developed jointly by CEA-DEN and EDF-R&D and also supported by IRSN and FRAMATOME-ANP. The major steps towards the next generation lie in new physical models and improved numerical methods. This paper presents the advances obtained so far in physical modelling for each scale. Macroscopic models of system and component scales include multi-field modelling, transport of interfacial area, and turbulence modelling. Two-phase CFD or CMFD was first applied to boiling bubbly flow for departure from nucleate boiling investigations and to stratified flow for pressurised thermal shock investigations. The main challenges of the project are presented, some selected results are shown for each scale, and the perspectives for future are also drawn. Direct Numerical Simulation tools with Interface Tracking Techniques are also developed for even smaller scale investigations leading to a better understanding of basic physical processes and allowing the development of closure relations for macroscopic and CFD models.

• Journal of Gastric Cancer
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• v.3 no.2
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• pp.93-96
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• 2003

Purpose: Synthetic absorbable monofilaments offer excellent glide characteristics and cause minimal tissue trauma as a result of their smooth monofilament structure and gradual absorption within the healing tissues. For these reasons, these suture materials are commonly used in various surgical fields such as gastroenterology, urology, gynecology, and plastic surgery. The aim of this study was to evaluate the safety and usefulness of a new synthetic absorbable monofilament, Glycoside-..-caprolactone-trimethylene carbonate interpolymer (GCT), in gastrointestinal anastomosis and closure. Materials and Methods: We evaluated 55 gastrointestinal anastomoses and closures using GCT $MONOSYN^{R}$, B. Braun, Germany) in 47 patients who underwent gastric surgery between December 2001 and May 2002 at Seoul National University Hospital. Patient's characteristics, operative procedure, surgeon's opinion of handling properties of GCT, and suture-related complications were analyzed. Results: There were 34 males and 13 females (M:F= 2.6:1) with an average age of 54.2 years old. Forty-five cases of gastrointestinal anastomosis (20 gastrojejunostomies and 25 jejunojejunostomies) and 10 cases of intestinal closure (7 gastrostomy closures and 3 duodenal stump closures) were performed in 41 cases of stomach cancer, three of peptic ulcer disease, two of GIST, and one MALToma. The handling properties of GCT according to the criteria of knot breaking load, knot security, and placing property were always scored with 7 to 9 points (10=excellent, 1=very poor). Two cases of postoperative complications ($3.6\%$) were noted. One was a leak of the gastrojejunostomy site which was successfully managed conservatively, and the other was a stricture of the gastrojejunostomy site which was managed by reoperation (side-to-side jejunojejunostomy). Conclusion: GCT seems to be an applicable suture material for various gastrointestinal anastomoses and closures.

• Journal of Veterinary Clinics
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• v.33 no.4
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• pp.221-224
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• 2016

An 8 month-old male Maltese (weighing 2.0 kg) was referred with loud heart murmur at routine physical exam in local animal clinic. Electrocardiogram found left ventricular hypertrophy pattern (4.5 mV R-wave). Diagnostic imaging studies revealed the elongation of left ventricle (LV) with classic triple bumps on the main pulmonary artery, aorta and left atrium on the ventrodorsal view of radiograph. Echocardiography revealed patent ductus arteriosus (PDA) duct and continuous turbulent shunt flow (maximal velocity 4.83 m/s) between the aorta and pulmonary artery with left to right direction. The PDA in this dog was successfully closed through femoral vein (transvenous approach) using a 5 mm Amplatz$^{(R)}$ Canine Duct Occluder. To the best of author's knowledge, this is the first case of PDA occlusion treated with Amplatz Canine Duct Occluder through femoral vein.

• Journal of the Korean Ceramic Society
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• v.33 no.5
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• pp.602-615
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• 1996

The purpose of the present study is to investigate the microstructural effect on the R-curve behavior in three aluminas with different grain size distributions by analyzing the bridging stress distribution. The crack opening displacement (COD) according to the distance behind the stationary crack tip was measured using an in situ SEM fracture method. The measured COD values in the fine-grained alumina agreed well with Wiederhorn's sollution while they deviated from Wiederhorn's solution in the two coarse-grained aluminas because of the increase of the crack closure due to the grain interface bridging in the crack wake. A numerical fitting procedure was conducted by the introduction of the power-law relation and the current theoretical model together with the measured COD's in order to obtain the bridging stress distribution. The results indicated that the bridging stress function and the R-curve computed by the current model were consistent with those computed by the power-law relation providing a reliable evidence for the bridging stress analysis of the current model. The strain-softening exponent in the power-law relation n, was calculated to be in the range from 2 to 3 and was closely related to the grain size distribution. Thus it was concluded from the current theoretical model that the grain size distribution affected greatly the bridging stress distribution thereby resulting in the quantitative analysis of microfracture of polycrystalline aluminas through correlating the local-fracture-cont-rolling microstructure.

• The Journal of Korea Robotics Society
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• v.12 no.4
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• pp.385-394
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• 2017

Side scanning sonar (SSS) provides valuable information for robot navigation. However using the side scanning sonar images in the navigation was not fully studied. In this paper, we use range data, and side scanning sonar images from UnderWater Simulator (UWSim) and propose measurement models in a feature based simultaneous localization and mapping (SLAM) framework. The range data is obtained by echosounder and sidescanning sonar images from side scan sonar module for UWSim. For the feature, we used the A-KAZE feature for the SSS image matching and adjusting the relative robot pose by SSS bundle adjustment (BA) with Ceres solver. We use BA for the loop closure constraint of pose-graph SLAM. We used the Incremental Smoothing and Mapping (iSAM) to optimize the graph. The optimized trajectory was compared against the dead reckoning (DR).

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.4
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• pp.277-284
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• 2021

This paper deals with multi-objective optimization using response surface method to improve the hydraulic performances of a 2 vane pump for wastewater treatment. For analyzing the internal flow field in the pump, steady Reynolds-averaged Navier-Stokes equations were solved with the shear stress transport turbulence model as a turbulence closure model. The impeller and volute variables were defined in the shape of the 2 vane pump. The objective functions were set to satisfy the total head at the design flow rate as well as to improve the efficiency. The hydraulic performance of the optimally designed shape was verified by numerical analysis results.