• Archives of Plastic Surgery
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• v.33 no.4
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• pp.503-505
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• 2006

Purpose: Cutis verticis gyrata(CVG) is a morphologic syndrome, typically occurring on the scalp, characterized by varing development of permanent folds and furrows conferring a corrugated or convoluted appearance which resembles the outer surface of the cerebrum. Cutis verticis gyrata can be categorized into primary and secondary types according to various etiologic factors and associated conditions which cause disease process. Methods: We report a case of essential primary cutis verticis gyrata in a 24-year-old male who did not have any other underlying or associated conditions. Results: After we made an incision to the galea aponeurotica of patient's scalp four times under local anesthesia, we dissected along the subapponeurotic layer and adjusted the flaps each other, and then sutured the flap. Conclusion: After the operation, the clear margin disappeared and it did not recur.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.27-34
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• 2000

HTS wires processed by PIT method are now available for magnet applications. But, those wires can not be used over 40 K due to weak link. This leads to necessity of development of coated conductor which can retain high $J_c$ at high field in liquid nitrogen. In this paper, various technical issues and the R&D status for both PIT wires and coated conductor were discussed. The difference of coated conductor's processes were also investigated and summarized. Various requirements for a design of HTS magnets were discussed. Anisostropic $J_c$ property with respect to magnetic field was considered to determine the coil's critical current. Low n value is a critical parameter to degrade a field stability with respect to time for a persistent mode HTS magnet. The relation between the margin of operation current and n value was investigated. Prototype HTS magnets with PIT wires are being developed for various applications such as crystal growth, MRI, magnetic separator and etc. HTS magnets will come into wide use in various fields of industries if the HTS wires with a low performance cost is developed.

• Journal of Chest Surgery
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• v.23 no.4
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• pp.758-763
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• 1990

A congenital fistulous communication between the coronary artery and the cardiac chamber or the pulmonary artery is a rare condition, but increasing cases with this anomaly are being recognized with wide spread use of cardiac catheterization and coronary arteriography. Recently we experienced one case of right coronary artery fistula which was associated with atrial septal defect. The patient was a 24 year old female who was admitted because of cardiac murmur, palpitation and dyspnea on exertion after pregnancy. Cardiac catheterization and selective coronary arteriography revealed that a fistulous communication, forming a large aneurysm, was noted from the right coronary artery emptied into the right ventricle. On the operation field, the right coronary artery was curved and markedly dilated from the aorta to the middle segment at acute margin of the right ventricle. The egg-sized aneurysm of dilated right coronary artery was noticed on right ventricle. The aneurysm was incised longitudinally and both the proximal opening and the termination site of the fistula were closed directly with aneurysmectomy. The right atrium was also opened to evaluate the fistulous termination site and repaired only small interatrial septal defect. Postoperative course was uneventful and she was discharged without problems

• Journal of Chest Surgery
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• v.33 no.7
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• pp.581-584
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• 2000

Because the penetrating cervical tracheoesophageal injury may be associated with significant morbidity and mortality, it is important to choose the optimal method of diagnosis and management in patient with tracheoesophageal injury. We obtained a satisfactory result from repair of tracheoesophageal injuries using cardiopulmonary bypass. If the bleeding from the unidentified deep injury and the spread of infection could be controlled, the repair using CPB might increase the margin of safety during operation in the similar cases.

• Journal of Chest Surgery
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• v.46 no.3
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• pp.230-233
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• 2013

While a diaphragmatic rupture commonly results from trauma to the abdomen and chest, a spontaneous diaphragmatic rupture is very rare. A 68-year-old male presented with chest pain that had originated while doing farm work in a squatting position. Images revealed a 5 cm defect of the left diaphragmatic dome, and the entire stomach was displaced into the thorax. The diaphragmatic defect was round and half had a well-demarcated margin. The remaining fragile tissue was completely excised and was closed primarily. The patient was uneventfully discharged and resumed with a normal diet 10 days after the operation.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.147-149
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• 2004

This paper presents a new velocity estimation strategy of a non-salient permanent magnet synchronous motor(PMSM) drive without high frequency signal injection or special PWM pattern. This approach is based on the d-axis current regulator output voltage of the drive system which has the information of rotor position error. The rotor velocity can be estimated through a rotor position tracking PI controller that controls the position error to zero. For zero and low speed operation, the PI gains of rotor position tracking controller have a variable structure. The PI tuning formulas are derived by analyzing this control system using the frequency domain specifications such as phase margin and bandwidth assignment.

• Journal of Korean Neurosurgical Society
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• v.51 no.1
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• pp.37-39
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• 2012

We present a rare case of massive intracerebral hemorrhage resulting from a small, superficially-located supratentorial cavernous malformation, or cavernoma. These lesions rarely lead to massive, life-threatening intracerebral hemorrhages. A 17-year-old female presented with a 3-week history of declining mental status. Brain computed tomography and magnetic resonance imaging revealed a sizable intracranial hemorrhage, within the right occipital region, associated with a small nodule at the hematoma's posterior margin. An emergency operation removed the entire hematoma and nodule. Histological examination of the nodule was compatible with a diagnosis of cavernous malformation. The patient's post-operative course was uneventful.

• 유체기계공업학회:학술대회논문집
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• 1998.02a
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• pp.203-209
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• 1998

Rotordynamic analysis of a multistage turbine pump using finite element method is performed to investigate the effects of seal wear on Its system behavior. Stiffness and damping coefficients of the 2-axial grooved bearing are obtained as functions of rotating speed. Stiffness and damping coefficients of plane annular seals are calculated as functions of rotating speed as well as seal clearance. As the clearance of seals become larger, these stiffness and damping coefficients decrease drastically so that there can be significant changes in whirl natural frequencies and damping characteristics of the pump rotor system. Although a pump is designed to operate with a sufficient seperation margin from the 1st critical speed, seal wear due to long operation may cause a sudden increase in nitration amplitude by resonance shift and reduce seal damping capability.

• The KSFM Journal of Fluid Machinery
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• v.13 no.6
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• pp.57-62
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• 2010

MW-class gas turbines are suitable for distributed generation systems such as community energy systems(CES). Recently, biogas is acknowledged as an alternative energy source, and its use in gas turbines is expected to increase. Steam injection is an effective way to improve performance of gas turbines. This study intended to examine the influence of injecting steam and using biogas as the fuel on the operation and performance a gas turbine combined heat and power (CHP) system. A commercial gas turbine of 6 MW class was used for this study. The primary concern of this study is a comparative analysis of system performance in a wide biogas composition range. In addition, the effect of steam temperature and injected steam rate on gas turbine and CHP performance was investigated.

• International Journal of Automotive Technology
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• v.7 no.2
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• pp.201-208
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• 2006

This paper describes the control philosophy of ESP(Electronic Stability Program) which consists of the stability control the fault diagnosis and the fault tolerant control. Besides the functional performance of the stability control, robustness of control and fault diagnosis is focused to avoid the unnecessary activation of the controller. The look-up tables are mentioned to have the accurate target yaw rate of the vehicle and obtained from vehicle tests for the whole operation range of the steering wheel angle and the vehicle speed. The wheel slip control with a design goal of wheel slip invariance is implemented for the yaw compensation and the target wheel slip is determined by difference between the target yaw rate and actual yaw rate. Since the ESP has a high severity level and the robust control is required, the robustness margin for the stability control is determined according to several uncertainties and the robust fault diagnosis is performed. Both computer simulation and test results are shown in this paper.