• Proceedings of the KSME Conference
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• 2007.05a
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• pp.746-750
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• 2007

Vertebroplasty has drawn much attention as a medical treatment for the compression fracture of spine, which strengthens the vertebral body and corrects deformity, and relieves pain in patients by injecting bone cement. However vertebroplasty can cause fracture on adjacent vertebra due to relative stiffness change. This study involves the biomechanical evaluation of the vertebroplasty especially on adjacent vertebral body. The finite element method has been employed to analyze the patient who was treated vertebroplasty under static and dynamic loading. For this study, a three-dimentioal model of the three-level ligamentous lumbar segment ($L1{\sim}L3$)is created from medical image data (CT)and compared with the experimental results in vitro.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.101-102
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• 2006

345kV 변전소는 국내 전력계통의 근간으로서 고장 시계통 안정도에 미치는 영향이 크기 때문에 고장 제거가 착신하고 신속해야 한다. 따라서 345kV 변전소의 보호 장치들은 CT, PT, 차단기(trip coil), 보호계전기, DC전원 등이 모두 2계열화되어 있으며 보호 계전기는 각 계열마다 주보호와 후비보호가 따로 구비되어 있다. 본 논문에서는 34skv 변압기 보호용 보호계전기에 내장된 계전요소들의 유기적인 성능 검증을 할 수 있는 동특성 시험에 관한 기반 구축 과정 및 결과에 대해서 기술한다.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1943-1950
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• 2010

Superimposition of horizontal and vertical curves may hamper the ride comfort and the running stability of train and largely affect the maintenance cost. However, in many cases, it's not easy to make a track plan because of the fixed points (bridge, tunnel, turnout, catenary system, etc.) to be avoided due to the geographic conditions or to be passed for utilization of existing structures. In this study, when the horizontal and vertical curves are superimposed, in order to optimize the horizontal curve in aspect of the ride comfort, the object function $P_{CT}$ was developed and verified by vehicle dynamic analysis. Also, the solution algorithm for simplified evaluation method was presented.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.12
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• pp.205-212
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• 2003

Many people are exposed to accidents by vehicles or sports. The most frequent injuries by these accidents is concerned with a knee joint. The three-dimensional surface model of a knee is needed for dynamic analysis of knee motion and knee reconstruction. three-dimensional motion data of a knee joint were obtained using X-ray and precise magnetic sensors. The surface data of a femur and a tibia were obtained using cross-sectional pictures by CT. The three-dimensional surface models of a femur and a tibia were made by the method of optimal triangular patch. Using obtained motion data, we simulated the motion of three-dimensional knee joint model.

• Parasites, Hosts and Diseases
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• v.45 no.2 s.142
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• pp.77-85
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• 2007

Among several diagnostic tools for clonorchiasis (Clonorchis sinensis infection), radiologic examinations are commonly used in clinical practices. During the 2 past decades, many reports regarding imaging findings of clonorchiasis were introduced. The basic imaging finding of clonorchiasis is diffuse dilatation of the peripheral intra-hepatic bile ducts, without dilation of the large intrahepatic or extrahepatic bile ducts. By this finding, however, active clonorchiasis cannot be differentiated from cured infection. Some recent radiologic studies suggested specific findings of active clonorchiasis. Besides direct demonstration of worms, increased periductal echogenicity on sonography and periductal enhancement on dynamic contrast-enhanced CT or MR imaging possibly represent active clonorchiasis. Those images of the liver clonorchiasis are known to be correlated with worm burdens (EPG counts) in their frequency and also severity. The images of cholangiocarcinoma associated with clonorchiasis show both the tumor with obstruction images and diffuse dilatation of the peripheral intrahepatic bile ducts. Radiological images can be a good practical alternative diagnostic method of clonorchiasis.

• Tuberculosis and Respiratory Diseases
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• v.57 no.5
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• pp.489-493
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• 2004

Unilateral pulmonary artery agenesis is a rare congenital anomaly usually associated with other cardiovascular anomalies such as tetralogy of Fallot or septal defect. Unilateral pulmonary artery agenesis without other coexisting cardiovascular abnormality (isolated unilateral pulmonary artery) is extremely rare and often asymptomatic until adulthood. In these patients, diagnostic clue is found in a plain chest roentgenogram, showing a hyperlucent contracted hemithorax. We have recently experienced a case of isolated right pulmonary artery agenesis, which was diagnosed by chest dynamic CT, perfusion scan, echocardiogram and 3-dimensional reconstruction cardiac CT angiography in a 50-year old female who had suffered from mild dyspnea on exertion and improved with conservative treatment. We report this case with a brief review of the relevant literature.

• Archives of Plastic Surgery
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• v.38 no.6
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• pp.775-782
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• 2011

Purpose: Nasal bone fracture is most common facial bone fracture. The cause of fractures is mainly trauma such as fighting, automobile accident and fall down, and it commonly involves young males. Very frequently nasal bone fractures are associated with other facial injuries such as orbital bone fracture, maxillary bone fracture and nasal septal deformities. Because of various dynamic directions of power are involved, phenomenon of fractures are also various and treatment cannot be simple. Methods: We studied and analyzed retrospectively 452 cases nasal bone fractures from January 2008 to December 2010. Diagnosis were made with physical examination, Nasal bone X-rays, Facial bone CT and 3D facial bone CT. Four surgeons are involved in treatments of these patients and applied different procedure along patient's condition and deformity. We analyzed the cause of nasal bone fractures, deformities, associate injuries and applied surgical technique, and patient's satisfaction rate. In this study, old nasal bone fractures were excluded. Results: Young male group was most commonly sustained nasal bone fracture and physical violence was most common cause of injury. 64 of 452 patient was involved associate injuries of face. Closed reduction were applied 246 cases and C-arm quide reduction were 167 cases and in 20 cases lateral osteotomy were applied. Approximately, more than 80% of the Patients were satisfied with the outcomes. Conclusion: Diagnosis and treatment of nasal bone fractures are considered simple but because of various deformity and associate injuries, treatment is not always simple and universal. Time to time, we face unsatisfied patient after treatment of nasal bone fractures. For obtaining satisfactory result, cause of injury and state of deformities and associate injuries such as nasal septal deformity should be evaluated properly and proper treatment should be applied.

• Journal of radiological science and technology
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• v.41 no.2
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• pp.123-128
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• 2018

Recently, the use of contrast agents has been increasing as a broader range of tests and dynamic tests have become common due to the development of equipment and imaging techniques such as Multi-Detector CT. However, the side effects of using contrast agents have been reduced by the development of non-ionic contrast agents, but they are still occurring often. The purpose of this study was to propose a method to minimize the side effect of contrast agent by using the amount of contrast agent injected to the brain angiography test to suppress excessive use of contrast agent and analyze the amount of contrast agent. Patients who were prescribed Brain Angiography due to cerebrovascular disease, According to the results of the comparison of the results obtained by dividing into 4 groups of 10ml each according to the amount of contrast medium injected with contrast agent according to the BMI of the patient, BA and SNR were not different between groups, and even if the amount of contrast injection was reduced, there was no problem in the evaluation of CT angiography through 3D reconstruction. This result shows that even if the contrast medium is injected into the blood vessels of the patient first and then the contrast medium is used as the physiological saline solution, the contrast medium is reduced by 40% it can be expected to minimize.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.3 no.1
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• pp.38-46
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• 2010

The lesions around hip joint including bone, joint and soft tissue can cause the pain. For diagnosis of these lesions, physical examination and simple X-ray were accomplished primarily. Some special cases, CT or MRI was a useful tool. However ultrasonography could provide non-invasive and dynamic images for the lesions of tendon and bursa, and it could be a useful tool for follow up after hip surgery. Due to the deep location of hip joint, ultrasonography is not easy for physician to examine and its application was impossible in some obese patients. This article deals with the normal and pathologic ultrasonographic findings of the hip joint and various applications using ultrasonography.

• Nuclear Engineering and Technology
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• v.21 no.3
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• pp.165-170
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• 1989

The strain rate effects on fracture toughness and fracture resistance characteristics of A533B-1 nuclear pressure vessel steels were examined in the quasi-dynamic test conditions through the microscopic investigation of the intense strain region around crack tip and the microroughness of fracture surface. J-value calculated from the recrystallization etch technique was the same as calculated from the modified-J when the crack extension is less than 1.5mm in a 1/2T-CT specimen. Local fracture strain was calculated from the fracture surface micro-roughness. The local strains were calculated to be the values of 1.8 and 2.0 and were much higher than the macroscopically measured values. It was nearly independent on strain rate and was regarded as a material constant in ductile dimpled rupture. The fracture toughness increased with increase in strain rate while the tearing modulus showed little variation.