• Journal of the Korean Society of Radiology
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• v.4 no.1
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• pp.11-17
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• 2010

A urolithiasis, also called calculus, is one of the brutal illnesses, which has constantly harassed humanbeings from time immemorial. However, there is no appropriate method of prevention so far. So, Urological therapy must be followed upon those patients. The biggest problem of urolithiasis is usually causing harsh pain, fever, and throw up. The pain would be more intensified when something came through the ureter or the moment of convulsion caused beyond transmission of urinary calculus. Even strong painkillers, such as fentanyl and Pethidine, can not handle those harshly pain easily. Therefore, a prompt action of medical check up and its therapy must be required to those patients. This thesis paper has put the accent on the specific therapy, known as ESWL (Extracorpereal Shock Wave Lithotripsy), which have generated quite optimum resolution to patients, who received harsh pain from Proximal ureteral stone and Mid ureteral stone and because of its low provability of pulverization. The results of the experiment confirmed that the stone, located between Proximal and Mid ureter, has lower provability of pulverization than distal ureter, because its accuracy rate on shock wave, in respect of breathing, are low. However, decrease in discharge interval have enhanced provability of pulverization. it can also intensify probability of pulverization and its safety by discharging high power with appropriate intervals, and that is more efficient than discharging low power with frequent time.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.441-446
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• 2009

Background: Side clamping of ascending aorta during proximal graft anastomosis in coronary bypassing surgery in-creases the risk of direct aortic injury as well as embolization of intimal atheroma. Heartstring proximal sealing system (Guidant Corporation, Santa Clara, Calif), developed to avoid aortic side clamping, may minimize risks of such complications. The aim of the current study is to compare the surgical outcomes of the two proximal anastomosis techniquesi.e., Heartstring system versus aortic side clamping in off pump coronary bypassing' surgery (OPCAB). Material and Method: From January 2003 to August 2008, 499 patients underwent OPCAB. Of them, proximal graft anastomosis was performed using Heartstring system in 182 patients (Group I) and conventional manual anastomosis in 317 patients (Group II). The two groups were compared for postoperative major complications and mortality. Result: Two groups showed similar characteristics in terms of preoperative demographic data, left ventricular ejection fraction, renal function and history of diabetes, hypertension and smoking. Although there was no inter-group difference in the history of cerebral ischemia (p=0.48), preoperative brain magnetic resonance angiography revealed greater incidence of severe carotid artery stenosis (>75% of lumen) in the Group I than in the. Group II (44.5% in the Group I and 30.0% in the Group II, p=0.003). There were no inter-group differences in postoperative mortality (p=0.40) and complications (p=0.47) including neurologic events (3 in the Group land 2 in the Group II, p=0.258). Whereas neurologic events all comprised transient ischemic attacks in the Group I, they comprised multiple embolic strokes in the Group II. One patient in the Group II experienced aortic dissection during proximal anastomosis which resulted in ascending aortic replacement. Conclusion: Although proximal anastomosis using Heartstring system did not show statistically significant benefit over aortic side clamping, the. absence of embolic stroke maybe a definite benefit which may be better defined through further studies over a larger cohort.

• Clinics in Shoulder and Elbow
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• v.15 no.1
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• pp.25-31
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• 2012

Purpose: The clinical and radiographic outcomes of the internal fixation, which were executed on patients over the age of 65 with proximal humerus fracture by using a polyaxial angular stable locking compression plate (Non-Contact-Bridging proximal humerus plate, Zimmer, Switzerland, NCB), were evaluated. Materials and Methods: Thirty two patients over the age of 65 among the proximal humerus fracture treated with NCB plate, between August 2007 and January 2011, were chosen as the subjects. The average age of patients was 71 years, and the average postoperative follow-up period was 11.5 months. The fractures included 14 two-part and 18 three-part fractures. The clinical results were evaluated, using the visual analog scale (VAS) score and the Constant score. The radiological results were evaluated by time to union and Paavolainen method, which measures the neck shaft angle. Results: At the last follow-up examination, the mean VAS score was 3 points and the mean Constant score was 64.5 points, with bone union achieved after the average of 16.2 weeks following the surgery in all the cases. The mean neck shaft angle was 125.9 and 24 cases had good results, while 8 cases had fair results by Paavolainen method, at the last follow-up. There were 1 case of delayed union and cerclage wire failure, and 3 cases of subacromial impingement. There were no complications, such as loss of reduction, nonunion, screw loosening, or avascular necrosis of the humeral head. Conclusion: Internal fixation, using a NCB plate, was considered to be an effective surgical method in treating proximal humerus fracture in the elderly patients, on whom the fixation of the fracture and maintenance of reduction are difficult.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.263-266
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• 1997

Three dimensional numerical model based on the finite element method(FEM) were developed to predict the mechanical behavior of hip implants. The purpose of this study is to investigate the stress distribution of two types of cementless total hip replacement femoral component -a straight stem and a curved stem, and to compare their effect on the stress shielding between two types by three dimensional finite element method. The authors analyzed von Mises stress in the cortex & stem and compared the stress between the straight and the curved stem. In comparison of stresses between two different design of femoral stem, there was 25% more decrease of stress in straight stem than curved stem in the medial cortex at proximal region. The straight stem had consistently much lower stresses than the curved stem throughout the whole medial cortex with maximum 70% reduction of stress. However, there was little change in stress between nature and 2 implanted femur throughout the lateral cortex. Stress of femoral stem was much higher in the straight stem than the curved stem up to 60%. The straight stem had more chance of stress shielding and a risk of fatigue fracture of the stem compared with the curved stem in noncement hip arthroplasty. In design of femoral stem still we have to consider to develop design to distribute more even stress on the proximal medial cortex.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.11
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• pp.4604-4622
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• 2015

It is not easy to reconstruct the geometrical characteristics of the distorted images captured by the devices. One of the most popular optimization methods is fast iterative shrinkage/ thresholding algorithm. In this paper, to deal with its approximation error and the turbulence of the decrease process, an adaptive proximal conjugate gradient (APCG) framework is proposed. It contains three stages. At first stage, a series of adaptive penalty matrices are generated iterate-to-iterate. Second, to trade off the reconstruction accuracy and the computational complexity of the resulting sub-problem, a practical solution is presented, which is characterized by solving the variable ellipsoidal-norm based sub-problem through exploiting the structure of the problem. Third, a correction step is introduced to improve the estimated accuracy. The numerical experiments of the proposed algorithm, in comparison to the favorable state-of-the-art methods, demonstrate the advantages of the proposed method and its potential.

• Journal of the Korean Data and Information Science Society
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• v.28 no.6
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• pp.1229-1244
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• 2017

In recent years, as demand for data-based analytical methodologies increases in various fields, optimization methods have been developed to handle them. In particular, various constraints required for problems in statistics and machine learning can be solved by convex optimization. Alternating direction method of multipliers (ADMM) can effectively deal with linear constraints, and it can be effectively used as a parallel optimization algorithm. ADMM is an approximation algorithm that solves complex original problems by dividing and combining the partial problems that are easier to optimize than original problems. It is useful for optimizing non-smooth or composite objective functions. It is widely used in statistical and machine learning because it can systematically construct algorithms based on dual theory and proximal operator. In this paper, we will examine applications of ADMM algorithm in various fields related to statistics, and focus on two major points: (1) splitting strategy of objective function, and (2) role of the proximal operator in explaining the Lagrangian method and its dual problem. In this case, we introduce methodologies that utilize regularization. Simulation results are presented to demonstrate effectiveness of the lasso.

• Journal of Chest Surgery
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• v.6 no.1
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• pp.89-94
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• 1973

Esophagel atresia and tracheoesophageal fistula may occur as separate entities but usually occur in combination. First described by Durston in 1670, esophageal atresia was not successfully treated until 1939 when Ladd in Boston and Leven in St. Paul obtained the first survivors utilizing the methods of gastrostomy, esophagostomy and extrapleural ligation of the tracheoesophageal fistula as multiple operations which required months of hospitalization. Two years later Cameron Haight performed the first successful primary repair and afterward about 2000 cases of esophageal atresia with distal tracheoesophageal fistula reported in the world. In Korea, there appeared about 27 cases in the literature and 8 successful repaired cases noted in these year. Anther report two cases of esophageal atresia, of which one case was successfully treated with Haight`s method. Case 1.: Normal full term delivered boy with chief complaints of respiratory difficulty and persistent drooling with chocking, 3. lkg, was admitted with emergency 5 hours after delivery. Physical findings revealed no specific abnormal signs except distended abdomen and grunting respiration. Esophagograrn and bronchogram revealed proximal esophageal atresia and distal tracheoesophageal fistula proximal to the carina. Parent refused operative therapy and patient died 24 hours after discharge. Case 2. :3. lkg. normal full term delivered girl was admitted 4 days after delivery with chief complaints of regurgitation after feeding, chocking, cyanotic spell and fever since the day after delivery. Physical examination revealed persistent drooling, grunting respiration, and fever with moderate dehydration. Tracheoesophageal suction and fluid therapy with antibiotics improved her condition and subsided ]pneumonic condition. Esophagogram revealed markedly dilated proximal esophagus as blind loop and stomach distended with gas, and repairing operation as Haight`s method was performed on the 7th day after delivery. Patient tolerated all the operative procedure well and recovered uneventfully. Esophagogram on the 7th postoperative day showed passage of the lipiodol through the anastomotic side with moderate stricture,and feeding permitted. Patient tolerated all the feeding amount well and discharged on the 11th postoperative day. Followup revealed intermittent regurgitation after feeding and corrected with bougination.

• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.250-260
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• 1995

Bases have been used in order to prevent the leakage of bleachingagents through dentinal tubules in bleached teeth. But the proximal surfaces where the actual resorption takes place havenot been protected. The purpose of this study was to compare the conventional basing method with the basing of the labial and two proximal surfaces to the cementoenamel junction. The bases were placed after conventional root canal treatment. Group I: 2mm thickness bases were placed to the level of labial cementoenamel junction line. Group II : 2mm thickness bases were placed to the level of all c-e J lines including cervical area. Control : No bases were placed. After placement of sodium perborate and 30% hydrogen peroxide mixtureinto the teeth, the changes of pH were measured. The results were as follows. 1. Group II showed smaller leakage of bleaching agents and was statistically significant difference compared to Group I.(p<0.05) 2. Group I showed no statistically significant difference compared to the control group. (p>0.05) 3. There were no significant among the upper and lower teeth groups in each group and between the groups.(p>0.05). According to the above results, it was considered that basing of the labial and proximal surfaces to the cementoenamel junction can reduce the leakage of bleaching agents during bleaching procedure of pulplessteeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.1
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• pp.12-20
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• 2021

The purpose of this retrospective study was to evaluate the survival rate by comparing Class II restoration using flowable resin composite with stainless steel crown in primary molars. Electronic medical records and radiographs of 1,504 primary molars with proximal caries of 590 patients from June 2015 to August 2019 were analyzed. With the collected data, survival analysis was performed using the Kaplan-Meier method. The 1-year survival rate of flowable resin composite in the primary molar was 98.5%, 3-year survival rate was 87.7%, and mean survival time was 39 months. There was no statistically significant difference between flowable resin composite and stainless steel crown (p = 0.896). Within the limits of this study, Class II restoration using flowable resin composite can be considered a promising option for the treatment of proximal caries in primary molars.

• Journal of Korean Neurosurgical Society
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• v.29 no.7
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• pp.886-890
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• 2000

Objective : placement of ventricular catheter is important to achieve long-term patency of the shunt system. We describe a method of calculating the insertion site, trajectory, and the length of the ventricular catheter using CT parameters in shunt surgery. Patients and Methods : These can be rapidly obtained using a caliper from a scout cut and two axial scans at lateral ventricular and upper 3rd ventricular level. To compare this technique with traditional one, we analyzed 40 consecutive patients who underwent shunt surgery. Results : Of 20 patients undergoing ventriculoperitoneal shunt insertion using this technique, none had poor location of the proximal catheter. In the counterpart, 9 patients had poor location(p＝0.001). The number of patients who required revision surgery were also lower in the group using this technique, but it was not statistically significant (4 versus 2, p＝0.422). Mean follow-up period was shorter in this technique group. Conclusion : This technique provides an accurate placement of the proximal catheter without special instrument or additional expenses.