• Nuclear Engineering and Technology
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• v.50 no.5
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• pp.751-757
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• 2018

In this article, a UV sensor that is an appropriate tool for fire detection has been designed and constructed. The structure of this UV sensor is an air-filled single-wire detector that is able to operate under normal air condition. A reflective CsI photocathode is installed at the end of the sensor chamber to generate photoelectrons in the ion chamber. An electric current is produced by accelerating photoelectrons to the anode in the electric field. The detector is able to measure the intensity of the incident UV rays whenever the current is sufficiently high. Therefore, the sensitivity coefficient of this sensor is found to be $7.67{\times}10^{-6}V/photons/sec$.

• Tribology and Lubricants
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• v.16 no.5
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• pp.351-356
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• 2000

The feasibility of an ultrasonic technique using a pulse-echo method of normal-incident compressional waves was evaluated for its sensitivity to the worn surface and near surface damage due to wear. Worn surfaces were generated at various oscillation frequency under a given load and amplitude and these surface were in situ monitored using a ultrasonic wave detection system. Analysis of the ultrasonic waves received from the worn surface revealed a close relationship between the surface and near-surface damage and the maximum echo-amplitude of the compressional waves. The ultrasonic technique was successful in assessing the level of severity of the worn surface in real time during the wear process. It is also shown that the wear depth can be easily measured by the calculation of change of the specimen thickness based on the wave speed measured for the specimen medium.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.10a
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• pp.155-158
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• 2010

본 연구에서는 최근 도심지 대심도 지하도로 및 침매터널등에서 중요성이 부각되고 있는 터널내 화재안전 설계를 위한 영상유고감지시스템의 성능평가를 수행하였다. 영상유고감지시스템(VIDS)의 성능 평가를 위하여 터널 내부에서 발생할 수 있는 유고상황을 5가지로 구분하여 보행자, 낙하물, 정지차량, 역주행, 연기발생등의 상황을 인위적으로 발생시켰으며 이에 따른 감지 능력을 평가하였다. 실험결과 2, 3회 걸친 지속적인 교정과 세부조정을 거친 후에는 보행자 98.3%, 낙하물 96.7%, 정지차량 100%, 역주행 100%, 연기감지 100%의 감지율을 나타내었으며 카메라의 설치거리 100m 이내에서 비교적 높은 감지율을 나타내었다. 영상유고감지기의 적용 신뢰도는 터널내 조도, 카메라의 설치 위치에 따른 영상 변화등에 의존적이었으나 대심도 터널등의 신속한 화재감지를 위한 대안으로 적용될 수 있을 것으로 판단되었다.

• Journal of the Korea Safety Management & Science
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• v.19 no.4
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• pp.63-76
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• 2017

This thesis provides background information on DFS carried out by the government in an effort to reduce the accident rate, cases of DFS in other advanced countries to study their risk detection, risk assessment, risk control measures, and cases in which application of DFS during the designing phase succesfully led to reduction of the accident rate. Till now, the focus has been on incident responses after the occurance of accidents, it describes the importance of considering safety during the desining process through safety results and cases.

• Nuclear Engineering and Technology
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• v.34 no.1
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• pp.22-29
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• 2002

The angular correlation effect was investigated for Co-60 ${\gamma}$-ray spectroscopy by using HPGe detector and the effective angular correlation was theoretically calculated by considering the finite detector solid angle. For the calculation of effective angular correlation, the detection efficiency as a function of ${\gamma}$-ray incident direction was obtained by using Monte Carlo method and the first interaction model. The results and the methods used in the calculation are discussed.

• Journal of the Optical Society of Korea
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• v.7 no.2
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• pp.113-118
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• 2003

A two-photon interference experiment is presented in which an entangled pair of photons generated from a parametric down-conversion was incident on two input ports of a Mach-Zehnder interferometer. The experiment was carried out using two photon coincidence detection with two detectors at the two output ports of the interferometer. The measured coincidence counts exhibit an interference effect with visibility of 0.75 at simultaneous inputs and 0.38 at inputs with different arrival times according to the degree of photon number entanglement.

• Progress in Superconductivity and Cryogenics
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• v.24 no.2
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• pp.23-26
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• 2022

A lossless transport of an arbitrary waveform in a frequency range of 10⁶-10⁹ Hz through a conduction channel in a cryogenic temperature is of importance for a high-speed operation of quantum device. However, it is hard to use a commercial oscilloscope to directly detect the waveform travelling in a device located in a cryogenic system. Here, we developed a cryogenic voltage sampling technique by using a Schottky barrier gate prepared on a surface of a GaAs/AlGaAs device, which revealed that an incident rectangle waveform can transport through a 1 mm long two-dimensional conduction channel without waveform deformation up to 20 MHz, while further study is needed to increase the detection frequency.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.1
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• pp.25-38
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• 2017

Many security threats are occurring around the world due to the characteristics of industrial control systems that can cause serious damage in the event of a security incident including major national infrastructure. Therefore, the industrial control system network traffic should be analyzed so that it can identify the attack in advance or perform incident response after the accident. In this paper, we research the visualization technique as network forensics to enable reasonable suspicion of all possible attacks on DNP3 control system protocol, and define normal action based rules and derive visualization requirements. As a result, we developed a visualization tool that can detect sudden network traffic changes such as DDoS and attacks that contain anormal behavior from captured packet files on industrial control system network. The suspicious behavior in the industrial control system network can be found using visualization tool with Digital Bond packet.

• Journal of Digital Convergence
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• v.14 no.6
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• pp.547-562
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• 2016

The purpose of this research was to provide the information of mandatory regulation for Korean sports facilities and the preliminary data for building sport safety management manual through sports facilities abroad and system status. Futhermore, based on the information of sports facilities safety management, this research performed the benchmarking of each country sports facilities safety management system. As a result, in the U.S, Department of Homeland Security(DHS) leads effort to achieve a safe, secure, and resilient homeland. In Germany, law & regulations, sports facilities safety guideline and expert extension have been reviewed. Germany is more realistic and practical than other countries. In Australia, Major Hazard Facilities(MHF) is responsible for eliminating the risk of a major incident. Emergency Management System(EMS) should spontaneously respond when the alarm is raised as early detection and intervention are vital to ensuring that a small incident does not escalate to become a major disaster.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.1 no.1
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• pp.79-88
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• 2002

As a part of NERI:;, Truck Shipment Safety Information is divided into Optimal Route Guidance system and Emergency Response system. This study which is for developing of Truck Shipment Incident Emergency Response System intends to prevent or early response damage caused by incidents through realtime monitoring about the position and the state of Hazard material transport truck. For this, we divide it into three scenarios; realtime monitoring, management of incidents, information provision to related organizations and present functional requirements and architecture coming with each scenario. As a result of the first step among total three steps, it would able to not only realtime management of trucks but also guide for auto-enforcement or management about illegal act like dumping scrapped material. It is now under examination about position of detection and technology of communication to application. From now on, it is expect to test in the range of Metropolitan after selecting appropriate technology.