• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.2
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• pp.111-117
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• 2013

In this paper, we have proposed novel technique to improve maintainability for training vehicle of underwater weapon system. In case of under water weapon, the fire procedure is related with operation of expulsion system in submarines. So the submarine crews should practice the complex fire procedure of weapon system by using training vehicle, which is safer and cheaper than operational weapon. After emitted from submarine, the training vehicle rise to the surface and should be withdrawn from the sea. The recovered training vehicle is transported to maintenance depot and pass through the recycling procedure including disassembling the vehicle, data acquisition & analysis, battery charge, replacing expandable components, testing the captive equipment, and assembling the vehicle. The disassembling & assembling of training vehicle which is composed of watertight section or airframe, is time-consuming work. So in this paper, we have studied the elements of recycling procedure and propose the method to exclude the assembling & disassembling work for maintainability improvement.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.361-366
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• 2001

The present study describes a practical estimation procedure about the pantograph under several severe aerodynamic load conditions. As the operating speed of the Korean Train Express(KTX) reaches 350km/h, structural safety at various conditions should be examined at the design stage. In the present study, a compact and reliable procedure is developed to get aerodynamic loads on each part of the pantograph regarding the typhoon condition, the train/tunnel interaction, the train/train interaction and the side wind condition. In the estimation procedure, 3-dimensional steady and unsteady CFD simulation around the high speed train facilitates assigning the external local flow condition around the pantograph. The procedure is verified using the results of the low speed wind tunnel test at JARI and applied to 7 flow conditions and 4 operation configurations.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.661-661
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• 2006

• Proceedings of the Korean Nuclear Society Conference
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• 2003.05a
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• pp.201-201
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• 2003

• Proceedings of the Korean Nuclear Society Conference
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• 2001.10a
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• pp.91-91
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• 2001

• Journal of Chest Surgery
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• v.19 no.2
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• pp.280-287
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• 1986

Between March 1978 and August 1985, 29 cases at various congenital heart diseases were reoperated because of remnant shunt of residual anomalies at Seoul National University Hospital. They were consisted of 10 cases of Tetralogy, 4 simple VSD, 6 complicated VSD. 3 partial ECD, and 5 other rare congenital anomalies. The interval between the initial and the second procedure ranged from 1 day to 122 months [mean; 26.9 months]. In 4 cases of them, the second procedure was done during initial hospitalization within 3 weeks post-operatively. The primary operation intended to be corrective surgery except four whose primary operation was palliative or exploratory one even though it was done with extracorporeal circulation. The indication for second operation was mainly residual shunt or valvular obstruction due to patch detachment or inadequate relief of stenotic lesion. Others were paravalvular leak, valvuloplasty failure, prosthetic valve failure, and inadequate primary diagnosis. Four patients were dead [14.3%]; three complicated VSD`s and one Tetralogy. There were 7 cases of nonfatal complication with subsequent improvement except one [diffuse cerebral dysfunction].

• Journal of Chest Surgery
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• v.49 no.2
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• pp.112-114
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• 2016

The half-turned truncal switch (HTTS) operation has been reported as an alternative to the Rastelli or $r{\acute{e}}paration$ $\grave{a}$ $l^{\prime}{\acute{e}}tage$ ventriculaire procedures. HTTS prevents left ventricular outflow tract (LVOT) obstruction in patients with complete transposition of the great arteries (TGA) with a ventricular septal defect (VSD) and pulmonary stenosis (PS), or in those with a Taussig-Bing anomaly with PS. The advantages of the HTTS procedure are avoidance of late LVOT or right ventricular outflow tract (RVOT) obstruction, and of overstretching of the pulmonary artery. We report the case of a patient who underwent HTTS for TGA with VSD and PS, in whom there was no LVOT obstruction and only mild aortic regurgitation and mild RVOT obstruction, including observations at 12-year follow-up. Our experience with long-term follow-up of HTTS supports a solution for late complications after the Rastelli procedure.

• 전기의세계
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• v.14 no.3
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• pp.10-17
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• 1965

This paper presents a method of the voltage-reactive power control in the long and short range operations and introduces a conception, "optimum control pattern." The optimum control pattern, aiming at the over-all system control, is defined as the optimum voltage distribution which minimizes the system operating cost under the conditions that the specified power be supplied and the system voltage be kept within the specified bounds. The following procedure was adopted to obtain this optimum pattern. In the first place, a power system was divided into three blocks, namely, load, substation and generator. Lagrange's, multiplier method is applied to each block in turn, paying attention only at the operating voltage distribution. Phase angles at each bus are then modified so that the continuity of active power is maintained. This procedure may be called "block relaxation method with Lagrange's multipliers." In a long range operation, this control pattern determines the optimum installation capacity of reactive power sources. In a short range operation, it also gives the reference state of real time control and the optimum switching capacity of reactive power souces. The real time control problem is also studied from the standpoint of cooperation of control devices such as generators, shunt capacitors, shunt reactors and ratio load controllers. A proposal for the real time control will contribute to the automation of power system operation in the near future. in the near future.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.855-859
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• 2009

In this paper, we introduce the estimation method by Risk or SIL(Safety Integrity Level) for the criterion of safety assurance and summarize each application method and target. IEC 62278(EN 50126) which is international standard for the specification and verification of the railway system RAMS indicate a criterion of safety assurance. Especially, it recommend the safety verification by continuous verification as the order of requirement establishment, design, manufacture, installation, operation, and maintenance for the equipment not easy to quantify the operation environment. In this paper, we study the SIL requirement allocation method relating to internal new system development and existing system improvement by analysing SIL recommendations which were used to understand SIL for a train control equipment in 1990s in IRSE and theoretically their allocation background. This paper help the safety management of Korea train control system to develope the quantitative management procedure as international level by analyzing the SIL requirement allocation by operation agency and the right SIL verification procedure by manufacture and indicating the example to assure safety because it is necessary for improvement and localization for the Korea train control system having highly dependence on aboard technology.

• Journal of the Korean Society for Railway
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• v.13 no.3
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• pp.257-263
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• 2010

Operation and maintenance cost of a rolling stock is generally higher than its acquisition cost. Therefore, it is necessary for reducing life cycle cost (LCC) to make rolling stocks easy and low costly for operation and maintenance. In addition, their operation and maintenance support systems should be effective and efficient. To accomplish this, operator should specify LCC requirements in the early stage of acquisition and make a contractor to provide the rolling stocks of low LCC. This article presents a procedure and a verifiable LCC model available in the general acquisition process where an operator specify requirements and a contractor provide the rolling stock meeting the requirements.