• Journal of Trauma and Injury
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• 제30권2호
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• pp.25-32
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• 2017

Purpose: The use of computed tomography (CT) to evaluate acute abdominal complaints has increased over the past two decades. We investigated how the clinical practice of patients with intestinal perforation has changed with the increasing use of abdominal CT in the emergency department (ED). Methods: We compared ED arrival to CT time, ED arrival to surgical consultation time, and ED arrival to operation time according to the method of diagnosis from 2003-2004 and 2013-2014. Results: In patients with gastrointestinal perforation, time from ED arrival to CT was shorter ($111.4{\pm}66.2min$ vs. $199.0{\pm}97.5min$, p=0.001) but time to surgical consultation was longer ($135.1{\pm}78.8$ vs. $77.9{\pm}123.7$, p=0.006) in 2013-2014 than in 2003-2004. There was no statistically significant difference in time to operation for perforation confirmed either by plain film or CT between the two time periods. There was no statistically significant difference in length of hospital or ICU stay or mortality between the two groups. Conclusion: With the increasing use of abdominal CT in ED, ED arrival to CT time has decreased and ED arrival to surgical consultation time has increased in gastrointestinal perforation. These changes of clinical performance do not delay ED arrival to operation time or adversely influence patient outcome.

• Journal of Chest Surgery
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• 제56권6호
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• pp.445-448
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• 2023

A 25-year-old man returned to Seoul National University Children's Hospital with mild dyspnea on exertion. He had undergone an arterial switch operation at 1 month after birth to correct a complete transposition of the great arteries and a ventricular septal defect. When the patient was 15 years old, dilatation of the neo-aortic sinus and annulus was first identified; since then, it had gradually increased. Given the young age of the patient and the degree of aortic regurgitation (AR), which was mild to moderate, we opted to perform a valve-sparing neo-aortic root replacement with aortic valve repair. Postoperative echocardiography showed successful reductions in the sizes of the aortic sinus and annulus, with only mild AR remaining.

• ETRI Journal
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• 제38권5호
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• pp.911-921
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• 2016

This paper presents the description, practical implementation, and stability analysis of a recently proposed, energy-efficient, medium access control protocol for wireless sensor networks, ALOHA-Q, which employs a reinforcement-learning framework as an intelligent transmission strategy. The channel performance is evaluated through a simulation and experiments conducted using a real-world test-bed. The stability of the system against possible changes in the environment and changing channel conditions is studied with a discussion on the resilience level of the system. A Markov model is derived to represent the system behavior and estimate the time in which the system loses its operation. A novel scheme is also proposed to protect the lifetime of the system when the environment and channel conditions do not sufficiently maintain the system operation.

• Nuclear Engineering and Technology
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• 제40권3호
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• pp.163-174
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• 2008

As part of the spent fuel treatment program at the Idaho National Laboratory, a vacuum distillation process is being employed for the recovery of actinide products following an electrorefining process. Separation of the actinide products from a molten salt electrolyte and cadmium is achieved by a batch operation called cathode processing. A cathode processor has been designed and developed to efficiently remove the process chemicals and consolidate the actinide products for further processing. This paper describes the fundamentals of cathode processing, the evolution of the equipment design, the operation and efficiency of the equipment, and recent developments at the cathode processor. In addition, challenges encountered during the processing of irradiated spent nuclear fuel in the cathode processor will be discussed.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권4호
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• pp.524-533
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• 2017

This paper presents a novel reset scheme for mm-scale sensing systems with stringent volume and area constraints. In such systems, multi-layer structure is required to maximize the silicon area per volume and minimize the system size. The multi-layer structure requires wirebonding connections for power delivery and communication among layers, but the area overhead for wirebonding pads can be significant. The proposed reset scheme exploits already existing power wires and thus does not require additional wires for system-wide reset operation. To implement the proposed reset scheme, a power management unit is designed to impose reset condition, and a reset detector is designed to interpret the reset condition indicated by the power wires. The reset detector uses a coupling capacitor for the initial power-up and a feedback path to hold the developed supply voltage. The prototype reset detector is fabricated in a $180-{\mu}m$ CMOS process, and the measurement results with the prototype mm-scale system confirmed robust reset operation over a wide range of temperatures and voltages.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2021년도 추계학술대회
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• pp.72-73
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• 2021

자율운항선박(MASS, Maritime Autonomous Surface Ship) 도입을 위한 국제해사기구의 논의가 본격화됨에 따라 국제항로표지협회 제27차 이네비게이션(ENAV) 위원회 워킹그룹(WG2)에서 MASS 운영지원을 위한 시스템 개발시 사이버보안(사이버 위험관리) 측면을 우선적으로 고려하도록 하는 논의가 진행되었다. 우리나라는 2020년 자율운항선박 기술개발사업을 착수하였으며, 2021년부터 사이버보안 기술개발을 위한 세부과제를 추진 중에 있다. 디지털 해상통신시스템 환경에서의 MASS 운용은 기존 해상통신환경에서는 고려되지 않았던 다양한 디지털 장비들의 네트워크 보안이 요구된다. 본 연구에서는 사이버보안 기술개발 세부과제에서 수행중인 MASS 운용 지원을 위한 네트워크 보안장비 기본 개념을 소개하고, 기초단계에서의 MASS 선박 적용을 위한 네트워크 보안장비 인터페이스를 정의한다.

• 한국암반공학회:학술대회논문집
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• 한국암반공학회 2008년도 국제학술회의
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• pp.101-114
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• 2008

An efficient mine management system demand constant attention of mine managers on the key performance indicators like production targets, equipment status, condition of haul roads, safety etc.. There is a wealth of information generated during day to day working of the mine. The success of a mining enterprise is a function of reliability of accumulated information and decision making on the basis of such information. In the present paper a computerized mine operations management system developed for a large opencast mine making use of the potential benefits of geographical information systems, real time kinematic global positioning systems and a communication network to improve the overall efficiency of the mine is presented.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2002년도 추계학술발표회요약집
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• pp.97-97
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• 2002

• 대한조선학회논문집
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• 제45권5호
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• pp.495-501
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• 2008

Samsung Heavy Industries (SHI) and NRC's Institute for Ocean Technology (IOT) collaborated on a project to predict the performance of a new design for a Suezmax size tanker that had acceptable open water performance but was also capable of operating in ice. The resulting hull form was a single screw, single rudder design with a bulbous bow, modified for operation in ice. An important design consideration is the ability of the ship to maneuver in different ice conditions. This paper presents the results of maneuvering experiments in pack ice and level ice, using a free running model.

• Journal of Power Electronics
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• 제13권4호
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• pp.584-591
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• 2013

In this paper, a hybrid booster power module with Si IGBT and Silicon Carbide (SiC) Schottky Barrier Diode (SBDs) is presented. The switching characteristics of the hybrid booster module are compared with commercial Silicon IGBT/Si PIN diode based modules. We applied the booster power module into a non-isolated on board vehicle charger with a simple buck-booster topology. The performances of the on-vehicle charger are analyzed and measured with different power modules. The test data is measured in the same system, at the same points of operation, using the conventional Si and hybrid Si/SiC power modules. The measured power conversion efficiency of the proposed on-vehicle charger is 96.4 % with the SiC SBD based hybrid booster module. The conversion efficiency gain of 1.4 % is realizable by replacing the Si-based booster module with the Si IGBT/SiC SBD hybrid boost module in the 6.6 kW on-vehicle chargers.