• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.816-823
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• 2007

Electric car tract plays the role of supply high electric power to the electric car from the substation by using Pantograph of the electric car. It is always exposed to the external atmosphere, which results in quite substantial fluctuations in current and voltage during operation of electric car. This generates possibility of occurrence of accident at all times. Since range of wiring metallic globe installed on the catenary cannot achieve complete electrical contact, accidents are occurring due to circulating current caused by arc caused by incomplete contact due to occurrence of hairline fracture of Pantograph due to pressure or vibration of wiring. Furthermore, rapid increase in the operational current due to increase in the operational frequency of the electric car is causing erosion and short circuit of the metallic globe at the contact points. This study on arc is generated as current transmitted out of the substation courses through power line or wiring metallic globe other than the main circuit as the current is being collected at the electric car through feeder and feeder divergence device. Accordingly, since heat generated by the arc becomes the cause for generation of circulating current due to melting of metal or softening of metal due to increase in temperature accompanying increase in contact resistance, this research shall describe causes and measures against occurrence of circulation current.

• 한국안전학회지
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• 제32권5호
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• pp.13-19
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• 2017

In this paper, study of vehicle fire cases caused by connector and power wiring of anti-lock brake system(ABS) module damage is presented. The purpose of ABS module is to improve braking and steering ability under sudden stop of the vehicle by repeatedly activating and releasing the brake with electric signal via electric control unit. The electric control unit for ABS may experience incomplete contact between power line and signal line or electrical breakdown on the printed circuit board by undergoing repetitive signal change which would consequently result in electrical heat and spark, eventually leading to automotive fire. Therefore, the purpose of this paper is to provide fundamental data by analyzing connector and power wiring of ABS module damage conducive to the precise investigation on the cause of vehicle fire.

• 한국수소및신에너지학회논문집
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• 제23권4호
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• pp.330-336
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• 2012

FCEV uses 250 ~ 450 V instead of using 12 V battery. High voltage vehicle can cause electric shock, fire and explosion accident. Therefore, it has potential factors that can cause hazard of safety for users. United states of America and Europe legislate regulations such as ECE R100, FMVSS 305 for regulating electrical safety during driving or after collision. The company manufacturing high voltage components must do advanced R&D about Method for improving and confirming the safety of high voltage. We develop the specific hardware components of high voltage wiring system for the power train system and power supply system of Hyundai Motors FCEV. This paper shows test method of insulative performance for securing the electrical safety of high voltage components such as power cable, connectors and buss-bar, and proposals the guide line value for human safety of FCEV according to the test result of our development components.

• 한국전기전자재료학회논문지
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• 제21권2호
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• pp.182-187
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• 2008

This paper dealt with the detection algorithm of series arcing, which is a cause of electric fires in low-voltage wiring systems. To find the distinguished electrical features of series arc, we simulated series arcing by the arc generator specified in UL1699. An electric heater, an inverter-controlled vacuum cleaner, and a phase-controlled incandescent lamp were used as loads to generate series arcing. A high-pass filter (HPF) with the low cut-off frequency of 3 kHz at -3 dB was fabricated and applied to separate the series arc signal from the AC voltage source. The experiment showed that the high frequency signal generates randomly during series arcing, and the phase-controlled incandescent lamp produces high frequency pulses even in normal state. In this case, the magnitude, the width, and the randomness of high frequency signal should be analyzed to estimate series arcing precisely.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.37-42
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• 2006

전선에서 전압강하는 열 손실을 의미한다. 이 열은 절연체의 특성을 변화시켜 절연성능을 저하시키게 되고 나아가 누전, 감전, 정전 및 화재 등의 사고를 일으키는 원인이 되기도 한다. 그러므로 전압강하에 대한 최적화 설계는 전기설비의 안전성과 경제성을 보장하는 중요한 요소가 되고 있다. 이에 저압의 전기설비인 가로등, 빌딩, 지하철역사 등 공공의 안전확보가 요구되는 다중 분산부하계통에서의 전압강하가 전기배선에 미치는 영향을 분석하고, 안전성 및 경제성 확보를 위한 전압강하산정 프로그램 및 최적화 방안을 연구 제시하고자 한다.

• 한국임상수의학회지
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• 제33권2호
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• pp.124-128
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• 2016

A 7-year-old intact female Maltese dog presented with a history of bite wounds. Physical examination revealed labored breathing, four puncture wounds with subcutaneous emphysema of the thorax, and paradoxical respiratory movement of the right thoracic wall. On radiography, a segmental fracture of the right 7th rib and a single fracture of the 8th rib were evident on the dorsal thorax. An inward displacement of the fractured segment and contusion of the right caudal lung lobe were identified with computed tomography. A diagnosis of pseudo-flail chest was made. Exploratory thoracotomy revealed a full-thickness muscular defect, a marked discoloration of the right caudal lung lobe, a segmental fracture of the right 7th rib, and a single fracture of the right 8th rib. Necrotic tissues were removed using surgical debridement. The fractured 7th and 8th ribs were corrected using a single interfragmentary wiring technique. The thoracic wall was reconstructed using the latissimus dorsi muscle flap. Additional thoracic stabilization using a thermoplastic splint was applied to correct paradoxical respiratory movement. The external splint was removed 4 weeks postoperatively. There was no evidence of respiratory abnormalities 18 months postoperatively.

• 한국항공우주학회지
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• 제49권10호
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• pp.849-858
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• 2021

항공기 내 장비의 장착 위치 결정은 환경조건, 감항성, 정비성 등 고려해야 할 사항이 많아 정량적인 기준을 세우기 힘들다. 또한 장비의 숫자 증가에 따라 설계안은 기하급수적으로 늘어나기 때문에 제한된 일정 내에 검토하기 위하여 설계자의 경험에 많이 의존하여 설계가 진행되고 있다. 본 논문에서는 설계안을 비교할 수 있는 정량적인 기준을 만들기 위하여 장비의 위치에 따른 와이어링 하네스 길이 및 중량을 계산하는 방법과 유전 알고리즘을 이용하여 와이어링 하네스의 중량과 장비들의 CG를 최적화하는 방법을 제안하였다. 그리고 최적설계와 실제설계를 비교하여 최적화 결과가 유용함을 확인하였다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 추계학술대회
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• pp.346-348
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• 2022

물리적으로 넓은 구역을 모니터링하기 위해서는 많은 CCTV가 필요하다. 실내에서 CCTV를 구축할 때는 배선 환경이 충분하여 많은 CCTV를 설치할 수 있다. 그러나 실외에서는 상대적으로 배선이 어렵다. 또 먼 거리를 모니터링할 때는, 모니터링 장소까지 배선 비용이 발생한다. 그러므로 물리적으로 먼 거리에 CCTV를 설치할 때, 무선 기술을 적용할 필요가 있다. 본 연구에서는 기존 CCTV 시스템의 구성을 확인하고 이를 무선 환경으로 전환하기 위한 요구사항을 도출하였다. 그리고 요구사항에 따라 무선 기반 지능형 CCTV 시스템을 제안하였다. 그 결과 본 연구에서 제안하는 무선 기반 지능형 CCTV는 무선 환경에서도 정상 동작함을 확인하였다. 본 연구는 Wifi 환경을 기준으로 연구하였으며, 이동통신 환경으로 확장하기 위한 추가 연구가 필요하다.

• Journal of Chest Surgery
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• 제48권4호
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• pp.265-271
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• 2015

Background: Stainless steel wiring remains the most popular technique for primary sternal closure. Recently, a multifilament cable wiring system (Pioneer Surgical Technology Inc., Marquette, MI, USA) was introduced for sternal closure and has gained wide acceptance due to its superior resistance to tension. We aimed to compare conventional steel wiring to multifilament cable fixation for sternal closure in patients undergoing major cardiac surgery. Methods: Data were collected retrospectively on 1,354 patients who underwent sternal closure after major cardiac surgery, using either the multifilament cable wiring system or conventional steel wires between January 2009 and October 2010. The surgical outcomes of these two groups of patients were compared using propensity score matching based on 18 baseline patient characteristics. Results: Propensity score matching yielded 392 pairs of patients in the two groups whose baseline profiles showed no significant differences. No significant differences between the two groups were observed in the rates of early mortality (2.0% vs. 1.3%, p=0.578), major wound complications requiring reconstruction (1.3% vs. 1.3%, p>0.99), minor wound complications (3.6% vs. 2.0%, p=0.279), or mediastinitis (0.8% vs. 1.0%, p=1.00). Patients in the multifilament cable group had fewer sternal bleeding events than those in the conventional wire group, but this tendency was not statistically significant (4.3% vs. 7.4%, p=0.068). Conclusion: The surgical outcomes of sternal closure using multifilament cable wires were comparable to those observed when conventional steel wires were used. Therefore, the multifilament cable wiring system may be considered a viable option for sternal closure in patients undergoing major cardiac surgery.

• 한국산학기술학회논문지
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• 제17권9호
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• pp.351-358
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• 2016

국내철도 노선에 사용되는 NS형 선로전환기는 1960년대 말 일본에서 도입 되어 국산화 과정을 거처 개량되어 현재까지 설치 운용하고 있다. 선로전환기는 열차운행 상 가장 취약한 개소로 관리되고 있으며 사소한 결함에도 대형 열차사고가 발생될 수 있어 선로전환기 관리는 매우 중요하다. NS 선로전환기는 기계적인 구성품 개량은 꾸준히 이루어졌지만 표시 동력 제어회로 등 전기적인 접속부의 개선 없이 50년 전 도입 당시 기술을 그대로 사용하고 있어 최근 도입 운영되고 있는 자동 무인운전 시스템과 인터페이스에 문제가 있을 수 있다. 또한, 기존 NS 선로전환기 배선세트는 회로제어기와 제어계전기를 고정한 상태에서만 점검이 가능하여 고장발생 시 복구를 위한 점검시간이 과다하게 소요될 뿐만 아니라 철도신호 숙련자만 점검이 가능하여 원활한 열차소통에 어려움이 있는 것이 현실이다. 따라서 본 논문에서는 국내 NS 선로전환기의 표시 동력 제어회로 등 전기적인 접속부에 대한 개선 방안을 도출하고 최적화된 NS 선로전환기의 개선방안을 제시하고 서울2호선 자동운전(Distance to go) 구간에 시제품을 제작 하여 설치하였다. 이를 보다 확대 적용하면 안정적인 신호시스템 구성과 더불어 효율적인 유지보수가 이루어져 철도이용 승객 서비스 증대 및 유지보수비용 절감 등의 효과가 있을 것으로 판단된다.