• Journal of Gastric Cancer
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• v.19 no.3
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• pp.355-364
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• 2019

Totally laparoscopic distal gastrectomy (TLDG) frequently involves the use of delta shaped gastroduodenostomy (DSG) for intracorporeal anastomosis. However, DSG has some drawbacks, and the book binding technique (BBT) was developed as a new technique to overcome these drawbacks. Subsequently, this technique was further improved with the development of modified book binding technique (MBBT). This study evaluated the safety and feasibility of MBBT in patients undergoing TLDG. Thirty-three patients who underwent TLDG with MBBT were retrospectively evaluated. The mean operation time was $277.6{\pm}37.1minutes$, including $51.9{\pm}15.7minutes$ for reconstruction. Two patients had anastomosis-related complications, one patient with stricture after leakage and 1 patient with stenosis. The former patient was treated with endoscopic balloon dilatation, and the latter was managed conservatively; neither required re-operation. MBBT is a safe and feasible technique, with acceptable surgical outcomes. It may be a good alternative option for the treatment of intracorporeal anastomosis in patients undergoing TLDG.

• Journal of the Korean Vacuum Society
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• v.22 no.3
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• pp.111-118
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• 2013

The influence of gas flow on the plasma generation in the atmospheric plasma jet is described with the theory of hydrodynamics. The plasma discharge is affected by the gas-flow streams with Reynolds number (Re) as well as the gas pressure with Bernoulli's theorem according to the gas flow rate inserted into the glass tube. The length of plasma column is varied with the flow types such as the laminar flow of Re<2,000 and the turbulent flow of Re>4,000 as it has been known in a general fluid experiments. In the laminar flow, the plasma column length is increased as the increase of flow rate. Since the pressure in the glass tube becomes low as the increase of flow velocity by the Bernoulli's theorem, the breakdown voltage of plasma discharge is reduced by the Paschen's law. Therefore, the plasma length is increased as the increasing flow rate with the fixed operation voltage. In the transition of laminar and turbulent flows, the plasma length is decreased. When the flow becomes turbulent as the flow rate is increasing, the plasma length becomes short and the discharge is shut down ultimately. In the discharge of laminar flow, the diameter of plasma beam exposed on the substrate surface is kept less than the glass diameter, since the gas flow is kept to the distinct distance from the nozzle of glass tube.

• Journal of the Korea Society for Simulation
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• v.27 no.2
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• pp.35-48
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• 2018

The study of air defense against North Korean tactical ballistic missiles (TBM) should consider the rapidly changing battlefield environment. The study for target re-designation for intercept missiles enables effective operation of friendly defensive assets as well as responses to dynamic battlefield. The researches that have been conducted so far do not represent real-time dynamic battlefield situation because the hit probability for the TBM, which plays an important role in the decision making process, is fixed. Therefore, this study proposes a target re-designation algorithm that makes decision based on hit probability which considers real-time field environment. The proposed method contains a trajectory prediction model that predicts the expected trajectory of the TBM from the current position and velocity information by using random forest and moving window. The predicted hit probability can be calculated through the trajectory prediction model and the simulator of the intercept missile, and the calculated hit probability becomes the decision criterion of the target re-designation algorithm for the missile. In the experiment, the validity of the methodology used in the TBM trajectory prediction model was verified and the superiority of using the hit probability through the proposed model in the target re-designation decision making process was validated.

• Journal of Navigation and Port Research
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• v.33 no.10
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• pp.659-664
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• 2009

LNG carriers have, up to 2006, mainly been driven by steam turbines. The Boil-Off Gas from the LNG cargo tanks has so far been used as fuel. This is a costly solution that requires special skills during construction and operation. Alternative propulsion systems offer far better fuel economical efficiency than steam turbines. Instead of previous practice using Boil-Off Gas as a fuel, the Re-liquefaction system establishes a solution to liquefy the Boil-Off Gas and return the LNG to the cargo tanks. This Re-liquefaction of Boil-Off Gases on LNG carriers results in increased cargo deliveries and allows owners and operators to choose the most optimum propulsion system. In this study, thermodynamic cycle analysis has been performed on two type of LNG Re-liquefaction system which was designed and adopted for the Q-Flex(216,000$m^3$) and Q-Max(266,000$m^3$) LNG carrier under construction at Korea ship yards and variable key factor was simulated to compare efficiency, power and nitrogen consumption of each Re-liquefaction system.

• Water for future
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• v.29 no.2
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• pp.209-219
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• 1996

The existing gate operation rule of Paldang hydroelectric plant has been used since the construction of the dam in 1973 except partial modification due to the construction of Chungju multipurpose dam in 1985. The water level near the downstream of Paldang dam has been lowered about 3 m because of the channel maintenance of Han River development project. Thus, the discharge estimation formula based on the submerged orifice type spillway has to be re-evaluated by considering various patterns of the gate operation rules and lowered channel bed. In this study, three types of gate openings were tested to select the proper gate operation rules through the hydraulic model test for various discharges and opening heights. Also, the numerical analysis has been performed to simulate the flow patterns of downstream. As a result, the gate operation rule, which opens 5 gates each time from the left side, was selected as the proper gate operation rule of Paldang dam.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.149-155
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• 2004

This paper presents how to find proper operating points of FACTS devices to enhance the steady-state security level considering line contigency analysis. Three generic types of FACTS devices such as series controllers, shunt controllers, and series-shunt controllers are introduced and applied to moximize a security margin and to minimize security indices. Security indices related to line flows and bus voltages are utilized and minimized iteratively in this paper. Contingency analysis is performed to detect the most severe single line fault. In various load conditions, FACTS devices are tested to establish appropriate preventive or corrective action without generation re-dispatching or load shedding. The FACTS operation scheme is verified on the IEEE 57-bus system in a line-faulted contingency.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.5D
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• pp.649-656
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• 2011

The increase in the traffic demand and behavioral pattern of its use reached the limit for the only means of road construction to bear; thus the multilateral efforts to find a solution to this problem together with the examination and research on this issue, among which the most representative strategy is Ramp Metering System controlling access traffic volume to connection roads. The operation standard and running time was re-established in consideration of geographical conditions and traffic circumstances by considering the standard of operation and running time of the currently operated Jangsu- Jungdong section of the outer ring expressway of Seoul. For this purpose, this research analyzed the operative standard of RMS home and abroad and suggested a new operative standard of ramp metering through the analysis of break points.

• Journal of the Korea Safety Management & Science
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• v.13 no.1
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• pp.121-126
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• 2011

The provisions regarding the standard cost for recycling stated under the Extended Producer Responsibility (EPR) since 2002, include different and complicated obligatory steps to be taken on a variety of subject items regarding the collection, the transportation and the treatment, making the corporations face in their calculating and executing the standard cost. This study presents more objective calculation scope and standard for the purpose of efficient operation of the standard cost for recycling, in consideration of the general industry perception toward cost issue as well as domestic/overseas case studies regarding the standard cost for recycling. Besides, the study presents the checking items and the calculation contents per step to calculate the standard cost for recycling. Therefore, it is expected not only to be used as the objective standard to calculate the standard cost for recycling, but also to contribute to increasing the work efficiency in the following ongoing re-calculation process and to maintaining the consistent operation of the institution.

• Advances in pediatric surgery
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• v.17 no.1
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• pp.45-50
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• 2011

Meckel's diverticulum (MD) has various clinical presentations and due to the limitation of imaging studies, pre-operative diagnosis is a challenge in pediatric patients. Recently, laparoscopic exploration has been suggested as a favorable method for the diagnosis and treatment of complicated MD. We investigated the results of laparoscopic-assisted surgery compared with open technique. We retrospectively studied patients who underwent resection of complicated MD at our institute from 1997 to 2010 and compared 11 treated by laparoscopic-assisted diverticulectomy (LD) with 11 treated by open diverticulectomy (OD) for complicated MD. Operation time was not significantly different in the two groups. Hospital stay and time to diet were not significantly different. Two patients were re-admitted due to mechanical ileus in the LD group. None of patients in either group needed re-operation. Considering the possibility of false-positive results with imaging studies and the cosmetic benefit, laparoscopic-assisted surgery is a safe and effective treatment modality to diagnose and treat complicated Meckel's diverticulum.

• Archives of Plastic Surgery
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• v.42 no.6
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• pp.741-745
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• 2015

Background Microvascular complications after free-flap breast reconstructions are potentially devastating problems that can increase patient morbidity and lead to flap loss. To date, no comprehensive study has examined the rates of salvage and the methods of microvascular revision in breast reconstruction. We reviewed the treatment of microvascular complications of free-flap breast reconstruction procedures over a seven-year period. Methods A retrospective review of all patients who underwent microvascular breast reconstruction at our institution between April 2006 and December 2013 was conducted. Based on their surgical records, all patients who required emergency re-exploration were identified, the rate of flap salvage was determined, the factors associated with flap salvage were evaluated, and the causes and methods of revision were reviewed. Results During the review period, 605 breast reconstruction procedures with a free lower abdominal flap were performed. Seventeen of these flaps were compromised by microvascular complications, and three flaps were lost. The overall salvage rate was 82.35%. No significant differences between the salvaged group and the failed group were observed with regard to age, BMI, axillary dissection, number of anastomotic arteries and veins, recipient vessel types, or use of the superficial inferior epigastric vein in the revision operation. Successful salvage of the flap was associated with a shorter time period between recognizing the signs of flap compromise and the take-back operation. Conclusions The salvage rate of compromised lower abdominal flaps was high enough to warrant attempting re-exploration. Immediate intervention after the onset of flap compromise signs is as important as vigilant postoperative monitoring.