• Composites Research
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• v.20 no.3
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• pp.8-16
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• 2007

Bending collapse of light-weight square tubes used for vehicle structure components is a dominant failure mode in oblique collision and rollover of vehicles. In this paper bending performances of aluminum-GFRP hybrid tube beams were evaluated in relation with bending deformation behavior and energy absorption characteristics. Aluminum/GFRP hybrid tube beams fabricated by inserting adhesive film between prepreg and metal layer were used in the bending test. Failure mechanisms of hybrid tubes under a bending load were experimentally investigated to analyze the bending performance as a function of ply orientation and composite layer thickness. Ultimate bending moments and energy absorption capacity of hybrid tube beams were obtained from the measured load-displacement corves. It was found that aluminum/GFRP hybrid tubes could be converted to rather stable collapse mode showing excellent energy absorption capacity in comparison to the pure aluminum tube beams. In particular, the hybrid tube beam with $[0^{\circ}/90^{\circ}]s$ composite layer showed a large improvement by about 78% in energy absorption capacity and by 29% in specific energy absorption.

• Advances in pediatric surgery
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• v.17 no.2
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• pp.125-132
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• 2011

The aim of this study was to compare peritoneal dialysis catheter insertion by the open method to the laparoscopic method. Twenty four laparoscopic and 10 open peritoneal dialysis catheter placements were performed in children between 2001 and 2008. Patient characteristics, operation related data, procedural complications and clinical outcome were compared. Although there were no cases of catheter obstruction, exit site infection or bleeding in the laparoscopic group, compared to the open method, there was no statistically significant difference between the two groups. Catheter removal rate due to complication was high in the open group and catheter survival rate was high in the laparoscopic group. We concluded that laparoscopic peritoneal dialysis catheter placement is feasible in children of all age groups with at least equivalent functional results compared to the open method. An advantage of laparoscopic catheter insertion is removal of the great omentum and easy fixation of the catheter to the abdominal wall.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.1
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• pp.8-15
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• 2014

The ablation characteristics of graphite nozzle throat insert is analyzed for the use in solid rocket propulsion system. The propulsion system is composed of three types of conventional nozzles, such as De-Laval type, blast tube type, and submerged type. Various kinds of propellants are used in the thirteen kinds of propulsion system that has different shapes of each other. Total thirty seven tests are performed. From the results of the analysis, it is found that the ablation rate is higher for the higher average chamber pressure and the higher concentration of oxidizing species in combustion gas.

• The Journal of the Acoustical Society of Korea
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• v.14 no.2
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• pp.5-15
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• 1995

An application of the cross correlation technique by adopting ultrasonic waves for water pipe flow measuring purpose is studied. It is a non-intrusive flow metering method by determining the time of the flight of the flow turbulent noise and its non-obstructing mechanism enables to reduce process energy loss due to the flowmeter obstruction. A digital signal processor for the purpose of the real time Fourier transform was employed for the fast time calculation of the flow velocity. The overall accuracy was found as about $1\%$ for flow velocities from 0.25 m/s up to 16 m/s and for the pipe inside diameters from 50mm to 248mm. The cross correlation technique can be used for the tap water utility including most common liquid flows.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.59-66
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• 2013

Lack of the space in many diesel vehicles make it difficult to design and install the catalytic muffler to reduce emissions. For this reason, inlet part of the catalytic muffler is made of L-type which has lower flow uniformity than conventional I-type, and catalytic muffler has complex internal structure by various insertions, which affect the flow uniformity and pressure drop of the systems. In this work, the flow characteristics such as flow uniformity and pressure drop have been numerically investigated by changing such various geometries as inlet shape, porosity, and outlet shape inside the muffler with the three-dimensional turbulent incompressible flow solver. Total 4 different cases are considered in order to find optimal configurations of the catalytic muffler in view of high flow uniformity and low pressure drop. The results show that Case 2 which has no induction cone and outlet perforated pipe has higher uniformity index and lower pressure drop than others considered in this work.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.9
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• pp.491-496
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• 2015

Generally, the phase of the refrigerants that circulate in air-conditioning systems is repeatedly changed from liquid to gas and from gas to liquid. In vapor-compression refrigeration, the refrigerant at the inlet of the evaporator is in a gas-liquid two-phase state; therefore, to enhance the heat-transfer performance of the evaporator, the even distribution of the refrigerant across multiple passages of the evaporator is essential. Unlike the distribution of a single-phase refrigerant, multi-phase distribution requires further considerations. It is known that the multi-phase distribution at the outlet of the distributor is affected by factors such as the operating condition, the distributor's shape, and the insertion depth of the outlet pipes; here, the insertion depth of the outlet pipes is especially significant. In this study, for a cylindrical distributor with a 90-degree bend entrance and three outlet pipes, the flow uniformity at the outlet pipes was numerically tested in relation to variations of the insertion depth of the outlet pipes.

• Journal of the Korean Society of Radiology
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• v.84 no.1
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• pp.280-285
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• 2023

Uterine leiomyoma is the most common benign pelvic tumor in female and being symptomatic is an indication for surgical removal. As laparoscopic surgery has been developed, some cases related to parasitic leiomyomas in the port site have been reported. A 40-year-old female who a history of previous laparoscopic surgery to remove uterine myoma 2 years ago visited in outpatient clinic of general surgery with palpable mass in left lower abdomen. Contrast enhanced abdomen CT and pelvis MRI were done to evaluate the mass. It was diagnosed parasitic leiomyoma in pathologic study after surgical removal and parasitic leiomyoma should be considered when patient visited presenting abdominal mass with the history of laparoscopic myomectomy.

• Journal of Broadcast Engineering
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• v.24 no.2
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• pp.329-340
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• 2019

Recently, broadcasting technologies have evolved as high-quality AV services such as domestic terrestrial UHD(Ultra-High Definition) broadcasting have been increasing, and broadcasting standards have been newly defined. Also, as network technology develops, contents are consumed not only in the country but also the world. Accordingly, content insertion technology, which is a method of providing suitable contents in accordance with the national and local environments, will be needed. This paper proposes a content insertion service system model and synchronization scheme using ATSC(Advanced Television Systems Committee) 3.0 Event Signaling standard under heterogeneous network environment of broadcasting network and internet network based on transmission standard DASH(Dynamic Adaptive Streaming over HTTP)/ROUTE(Real time Object delivery Over Unidirectional Transport) and MMT(MPEG Media Transport) of terrestrial UHD broadcasting. It also verifies that the service operates in an environment that meets the broadcast standard.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.403-409
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• 1996

Background : Pleural fluid collections may pose a difficult therapeutic problem. Complete drainage of complicated effusions or empyemas and reexpansion of atelectatic lung are important in obtaining a satisfactory clinical outcome. The usual approach to the diagnosis and treatment of patients with pleural effusion and empyema has been with needle thoracentesis and chest tube drainage. With chest tube drainage, technical difficulties and failures may occur as a result of improper tube drainage, particularly when there is a loculation or multiple and inaccesible collections. Fluoroscopic or sonographic guidance facilitates the proper tube insertion and drainage. Method : Twenty eight patients were required for tube drainage due to pleural fluid collections between January 1994 to February 1996. The author compared the results of drainage under applying each different method between blind chest tube insertion and image guided catheter insertion. Results : The conventional blind chest tube group comprised 14 patients; 6 empyema, 6 tuberculous effusion, and 2 parapneumonic effusion. The image guided catheter group of smaller french were composed of 14 patients; 2 empyema, 6 tuberculous effusion, 5 parapneumonic effusion, and 1 effusion of undetermined origin. Radiologic improvement with successful drainage was noticed in 79% with the blind chest tube group, whereas in 93% with the image guided catheter group. The complication with the latter method was unremarkable. Conclusion : Image guided catheter drainage was safe and highly successful in treating patients, not only with complicated effusion also with loculated empyema. Image guided catheter drainage offers an alternative in patients in whom closed drainage is required as the initial treatment.

• Journal of the Korean Orthopaedic Association
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• v.56 no.4
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• pp.310-316
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• 2021

Purpose: Septic arthritis of the knee is an orthopedic emergency that requires early diagnosis and surgical treatment. This study examined the effectiveness of drain insertion and irrigation in the treatment of septic arthritis of the knee under local anesthesia. Materials and Methods: A retrospective study was conducted on nine cases (eight patients) diagnosed with septic arthritis of the knee from September 2017 to February 2020 and treated with drain insertion and irrigation under local anesthesia. After penetrating through the superolateral portal to the superomedial portal and inserting the drain, daily irrigation of approximately 3 L of normal saline was done. The following were investigated: age, sex, underlying disease, cause, degree of osteoarthritis, time from diagnosis to surgery, duration of hospitalization, duration of normalization of C-reactive protein, and smear and culture. Results: The initial white blood cell count of joint fluid was 71,472±51,667/mm³ (32,400-203,904/mm³), and polymorphic leukocytes were 91.1%±2.6% (86%-95%). The average time from diagnosis to surgery was 8.3±1.3 hours (6-10 hours), and the irrigation period was 8.2±3.2 days (4-15 days). The average length of hospitalization was 20.8±8.7 days (9-37 days). There was no reoperation or recurrence. Smear and culture tests were not identified. Conclusion: In the treatment of septic arthritis of the knee, the insertion of a drain tube and irrigation under local anesthesia is a relatively fast and simple method to reduce pain by repetitive draining of purulent joint fluid and can be used as an alternative treatment for patients with a risk of general or spinal anesthesia.