• 전기학회논문지
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• 제64권5호
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• pp.830-837
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• 2015

A study which is to develop the low-cost urban railway system for low-density line such as Gwang-ju subway Line 2 is in progress, and its TCS(Train Control System) is required as an economic system which is able to train operation suitable in low-density line. We have developed the signaling equipment which is configured with automatic block system between stations, and the control center's equipment in order to meet the requirements of TCS mentioned above. In this paper, we propose the control procedure of ATS to be required for train operation management in the low-density line such as Gwang-ju subway Line 2. The control procedure of ATS considered all features such as the requirements analysis for train operation management, the functions of train control system to be applied and the block type. Also, it considered the station(interlocking, passenger, turn-back) type, station control(stop, route, departure, turn-back departure, turn-back) type, and train operation management for exiting and entering depot. The ATS control procedure proposed in this paper has an advantage in the cost and efficiency through unification and optimization of its function. And in cost of operating and maintenance, the ATS system has a feature that can be significantly reduced.

• 한국항공운항학회지
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• 제29권4호
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• pp.105-116
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• 2021

The importance of a systematic approach to collect, process, analyze, and share safety data in aviation safety management is continuously increasing. Accordingly, the domestic aviation industry has been making efforts to build a Big-data platform that can utilize multi-field safety data generated and managed by various stakeholders and to develop safety management technology based on them. Big data platforms not only must meet appropriate technical requirements, but also need to establish a management system for effective operation. The purpose of this study is to suggest the requirements of the aviation safety big data platform operation procedure and plan by reviewing the advanced overseas cases (FAA ASIAS). This study can provide overall framework and managerial direction for the operation of the aviation safety big data platform.

• 산업경영시스템학회지
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• 제23권58호
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• pp.17-27
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• 2000

In FMS where tool movement policy is adopted, a mathematical model has been developed which determines the selection of a tool type for each operation and tool loading-part assignment simultaneouly. The objective is to minimize the total cost of operation including machining time cost, tool cost, tool replacement and loading time cost, and tool change time cost. Due to the complexity of the problem, an approximate solution procedure has been developed utilizing the special structure of the model. Tool selection was determined first to allocate one tool type to each operation considering more than one tool type alternatives for each operation. Tool loading-part assignment was determined to minimize tile total number of tool changes due to part mix based on the tool selection.

• Journal of Chest Surgery
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• 제45권3호
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• pp.141-147
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• 2012

Background: Although the aortic valve-sparing procedure has gained popularity in recent years, it still remains challenging in patients with advanced aortic regurgitation (AR). We compared the long-term outcomes of the aortic valve-sparing procedure with the Bentall operation in patients with advanced aortic regurgitation secondary to aortic root dilatation. Materials and Methods: A retrospective review of 120 patients who underwent surgery for aortic root dilatation with moderate to severe AR between January 1999 and June 2009 was performed. Forty-eight patients underwent valve-sparing procedures (valve-sparing group), and 72 patients underwent the Bentall procedure (Bentall group). The two groups' overall survival, valve-related complications, and aortic valve function were compared. Results: The mean follow-up duration was $4.9{\pm}3.1$ years. After adjustment, the valve-sparing group had similar risks of death (hazard ratio [HR], 0.61; p=0.45), and valve related complications (HR, 1.27; p=0.66). However, a significant number of patients developed moderate to severe AR in the valve-sparing group at a mean of $4.4{\pm}2.5$ years of echocardiographic follow-up (p<0.001). Conclusion: Both the Bentall operation and aortic valve-sparing procedure showed comparable long-term clinical results in patients with advanced aortic regurgitation with aortic root dilatation. However, recurrent advanced aortic regurgitation was more frequently observed following valve-sparing procedures.

• Archives of Plastic Surgery
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• 제45권4호
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• pp.340-344
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• 2018

Background In performing extended latissimus dorsi (ELD) flap procedures, a skin paddle design on the bra line helps reduce visible scarring. This improves the patient's satisfaction with the outcome. However, such a design leads to a longer operation time and increased fatigue of the surgeon due to the narrow operative field. In this study, the authors propose a method that elongates the axillary incision line posteriorly by 1.5 cm from the lateral border of the latissimus dorsi muscle. We examined whether this method could shorten the operation time and compared the incidence of complications between patients who underwent this novel procedure and patients who underwent the traditional procedure. Methods In this study of patients who underwent ELD flap procedures for immediate breast reconstruction, 89 underwent surgery with the elongated axillary incision and 45 underwent surgery without the elongated incision. The total operation time and complications were retrospectively examined based on the patients' medical records, and we examined whether there was any statistically significant difference in the total operation time. Results In the experimental group with the elongated axillary incision, the operation time ranged from 125 to 255 minutes (median, 175 minutes). In contrast, in the control group without the elongated axillary incision, the operation time ranged from 142 and 340 minutes (median, 205 minutes). The operation time was statistically significantly different between the two groups, and no significant complications were observed in the experimental group. Conclusions Elongation of the axillary incision alone may shorten the operation time of the ELD flap procedure without causing additional complications.

• Journal of Chest Surgery
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• 제28권8호
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• pp.759-765
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• 1995

We reviewed our experiences on 33 patients who underwent a bidirectional cavopulmonary shunt[BCPS from February 1992 to July 1994. There were 19 male an 14 female patients, and their weight ranged from 4.4 to 13.3 Kg[mean weight 8.4 $\pm$2.9 Kg . The age ranged from 2 to 55 months [mean age 16.7 $\pm$15.5 months . Their diagnosis included single ventricle group in 16, unbalanced ventricles in 8 whose associated anomalies were double outlet right ventricle, transposition of great arteries and total anomalous pulmonary venous return, tricuspid atresia in 7, hypoplastic left heart syndrome in 1 who underwent a Norwood procedure and double outlet right ventricle with pulmonic stenosis and tricuspid stenosis in 1 who underwent biventricular repair. Among them 10 patients had received other palliative operation before [Norwood procedure 1, pulmonary artery banding 3, modified Blalock-Taussig shunt 6 . The BCPS operations were performed under the cardiopulmonary bypass. 16 patients underwent unilateral BCPS and 17 patients who had bilateral SVC underwent bilateral BCPS. Three patients whose associated anomalies were interruption of IVC underwent total cavopulmonary shunt. There were 5 operative deaths [mortality rate 15.1 % and 2 late deaths. The risk factor for the operation was high mean pulmonary artery pressure [p value<0.05 . The survivors showed good postoperative course and their postoperative oxygen saturation was increased significantly compared to that of preoperative status[p value<0.05 .Conclusively, BCPS operation is effective and safe palliative procedure for the many cyanotic complex congenital anomalies with decreased pulmonary blood flow especialy for the patients who have the high risk factors for Fontan operations.

• 대한후두음성언어의학회지
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• 제9권2호
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• pp.152-155
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• 1998

Laryngeal framework surgery to improve change the voice is a challenging development in phoniatric surgery. Basically two categories can be distinguished : (1) attempted medialization of the vocal fold, as for the treatment of paralytic dysphonias (2) adjustment of the vocal fold's tension of transsexuals or mutational dysphonia. Vocal pitch can be elevated by various surgical technique 1) cricothyroid approximation 2) A-P expansion of the thyroid ala 3) longitudinal incision in the cords 4) intrachondral injection of the steroid, and 5) evaporation of the cords by $CO_2$ laser. We have experienced a case of pitch elevation procedure after transsexual operation. After transsexual operation, he had received anterior commissure laryngoplasty modified from Le Jeune with no change in voice pitch(Fo=110Hz). 8 monthes later, he had received cricothyroid approximation resulting in pitch elevation(Fo=160Hz).

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 춘계학술대회 논문집
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• pp.203-207
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• 2003

As the upending is one of the critical steps in the installation of offshore structure, datail procedure of upending operation is studied in the paper. For larger offshore structure installation, launching method is often applied. However after launching, the upending process is to be followed. To ensure successful upending operation, datail process is analysed considering various factors affecting on the operation including reserved buoyancy, free flotation position, seabed clearance, ballast and hook load. To investigate the influence of each factor on the procedure, twelve numerical jacket models with various dimensions are simulated and studied. From the study, it is revealed that the increase of buoyance and decrease of self weight generate a large seabed clearance. The law seabed clearance during flooding creates higher hook load and height. The paper also introduces a guideline for the related structure design and construction with the effects of contribution factors in the upending operation.

• Journal of Chest Surgery
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• 제51권6호
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• pp.395-398
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• 2018

Neo-aortic insufficiency associated with root enlargement following an arterial switch operation is a serious late complication. To achieve successful surgical correction of this condition, multiple factors should be considered, including the individual patient's anatomy, the challenging nature of the redo procedure, and the patient's young age. However, limited publications have described the use of valve-sparing techniques for the treatment of neo-aortic insufficiency associated with root enlargement following an arterial switch operation. Herein, we report our recent experience of a valve-sparing aortic root procedure with ascending aorta and hemiarch replacement despite the presence of a discrepancy in leaflet size and nearby severe adhesions.

• Archives of Reconstructive Microsurgery
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• 제19권2호
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• pp.101-107
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• 2010

Purpose: The free flap has been widely used as one stage reconstructive procedure the skin and soft tissue defect. The secondary adjuvant operations are often needed for better results as functional and aesthetic compartment. Therefore, we focus on the secondary adjuvant surgeries for better outcome after free flaps. Methods: One hundred ninety six consecutive patients underwent free flaps between January, 2002 and February 2009. The cases constituted ninety two male patients and one hundred four female patients. For the patients who got free flap operation, we investigated secondary adjuvant operations what type of procedures was applied according to the reconstructed sites. All clinical data were based on the patient's medical records. Results: Of one hundred ninety six patients in whom free flap was performed, a total of eighty two patients(41.8%) received the secondary adjuvant operation. Because of many patients got multiple secondary adjuvant operations, the number of the secondary adjuvant operation become one hundred fifty five cases. The most common used procedure is a liposuction, and the second one is a lipoinjection. Conclusion: As the secondary adjuvant operation like a liposuction, lipoinjection, etc., satisfaction for operative result was increased in the aspects of function and aesthetics. So the secondary adjuvant operation in free flap surgeries contributed in raising the patient's quality of life.