• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.332-335
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• 2011

Electro-Mechanical Ignition Safety Device(EMISD) for solid rocket motor is designed and manufactured. The EMISD utilizes a true rotary solenoid for arming mechanism and an electric squib(initiator) for generating ignition energy. In order to prove the ignition capability of the EMISD, 10-cc Closed Bomb Test(CBT) is performed, which measures the pressure built by high temperature and high pressure gas generated by operating EMISD.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.3
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• pp.328-331
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• 2008

This study presents on the analysis fire hazards of drum type electric washing machine. In order to analyze fire hazards fire experiment is conducted. The fire experiment is conducted to simulate under the normal condition and abnormal condition. The experiment under the abnormal condition is simulated in safety device failure, situation of accumulated dust and tracking phenomenon caused by humidity. The results show that fire hazard is high at the abnormal condition. In this paper, we suggest to use the safety device of low operating temperature in electric washing machine for reducing fire hazard.

• Journal of the Korean Society of Safety
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• v.31 no.6
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• pp.19-24
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• 2016

One of key parameters on lightning protection system design of electric, information and communication system is grounding impedance. Earth impedance includes numerous information about earthing performance of grounding system. This paper suggests grounding impedance measuring device which is comprised of wideband current source, voltage and current measuring components. We used IQ Demodulation to measure more accurate phase difference of voltage and current. The range of frequency is up to 1 MHz that is IEEE defined as the range of lightning surge. We compared developed grounding impedance measuring device with existing one to test its performance, and we used grounding system while we implemented measurement and analysing by using fall of potential method IEEE Std.81 proposed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.703-704
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• 2010

The environmental tests simulating the flight condition have been performed to manufacture the high reliable safety and arming device(SAD). A motor assay in preliminary design was reinforced with the structure to resist severe vibration and shock environment, and the design change had been verified by conducting the principal environmental test again.

• Journal of the Korea Society of Computer and Information
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• v.22 no.11
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• pp.49-55
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• 2017

Recently, for safety of people, there are proposed so many technologies which detect density of people at the specific place or space. The representative technology for crowd density estimation was using image analysis method from CCTV images. However, this method had a weakness which could not be used and which's accuracy was lower at the dark or smog space. Therefore, in this paper, to solve this problem, we proposed a user density estimation system at closed space using high frequency and smart device. The system send inaudible high frequencies to smart devices and it count the smart devices which detect the high frequencies on the space. We tested real-time user density with the proposed system and ten smart devices to evaluate performance. According to the testing results, we confirmed that the proposed system's accuracy was 95% and it was very useful. Thus, because the proposed system could estimate about user density at specific space exactly, it could be useful technology for safety of people and measurement of space use state at indoor space.

• Korean Journal of Computational Design and Engineering
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• v.19 no.2
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• pp.157-168
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• 2014

In this paper, HSE (Health and Safety Environments) research with smart device and biometrics is conducted for the worker's HSE enhancement in the manufacturing shop floor. Today, various kinds of smart devices are popularized extensively. In addition, the wearable type devices are being introduced such as google glass very recently. Smart device of werable type is exptected to bring great opportunity out in terms of HSE functionality. Smart devices of phone or tablet type are being used for on-line work between control center and manufacturing shop floor by virtue of wireless communication. However, those devices are not appropriate for detecting of worker's physical senses such as temperature and pulse. In this paper, we developed a glass type smart device and required funictions for HSE enhancement with the investigation of biometrics technology. Also, required sensors are investigated for the detecting of temperature, pulse and noxious gasses. Smart device of glass type has advantages in that most senses of personnel are gathered around faces, and also it's possible to detect neutral axis of body because the wearing location is fixed. We expect that the proposing HSE product of glass type smart device could contribute the enhancement of the HSE of manufacturing shop floor.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.576-577
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• 2005

In this paper, the oxidization characteristics were analyzed according to the shapes of Residual Current Protective Device(RCD) contacts. RCD is an electrical safety device specially designed to immediately switch the electricity off when electric leakage is detected at a level harmful to a person using electrical equipment. The shapes of RCD contacts are a little bit different according to the models. When RCD is turned on, stationary and moving contact do not fit together. So, it can cause the increase of contact resistance. To discover the deterioration characteristics of RCD contacts by switching repetition, the contacts were analyzed by stereo microscope, Scanning Electron Microscope(SEM) and Energy Dispersive X-ray Spectrometer(EDS).

• Korea Journal of Hospital Management
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• v.23 no.4
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• pp.15-25
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• 2018

Purposes: The objectives of this study present the direction of the criteria for the separately reimbursement of therapeutic medical device. Methodology: We summarized experts' opinion using Delphi survey and Analytic Hierarchy Process(AHP). 48 experts were gathered from Medical Insurance Review Nurses Association, medical device industry, academy and association, Medical Device Expert Evaluation Committee. Descriptive statistics, consistency index, content validity ratio were analyzed. Findings: Clinical utility, patient safety, infection control, cost-homogeneity, cost-effectiveness showed high feasibility and importance, but market contribution and functional utility showed low feasibility and importance in a relative sense. The results of functional utility differed between clinical and non-clinical experts. Measurability was low across the whole area. Among the criteria for the separately reimbursement of therapeutic medical device. Patient safety/infection control and clinical utility showed the highest relative importance values, analyzed using AHP. Practical Implications: Patient safety and infection control are needed to be considered as one of Value Assessment Criteria. It is important to find out how to improve the measurability of therapeutic medical device.

• Journal of radiological science and technology
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• v.45 no.2
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• pp.127-134
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• 2022

In order to overcome the image quality limitations of the conventional C-arm, a flat panel detector (FPD) is used to enhance spatial resolution, detective quantum efficiency, frame rate, and dynamic range. Three-dimensional (3D) visualized information can be obtained from C-arm computed tomography (CT) equipped with an FPD, which can reduce patient discomfort and provide various medical information to health care providers by conducting procedures in the interventional procedure room without moving the patient to the CT scan room. Unlike a conventional C-arm device, a C-arm CT requires different basic safety and essential performance evaluation criteria; therefore, in this study, basic safety and essential performance evaluation criteria to protect patients, medical staff, and radiologists were derived based on International Electrotechnical Commission (IEC) standards, the Ministry of Food and Drug Safety (MFDS) standards in Korea, and the rules on the installation and operation of special medical equipment in Korea. As a result of the study, six basic safety evaluation criteria related to electrical and mechanical radiation safety (leakage current, collision protection, emergency stopping device, overheating, recovery management, and ingress of water or particulate matter into medical electrical (ME) equipment and ME systems: footswitches) and 14 essential performance evaluation criteria (accuracy of tube voltage, accuracy of tube current, accuracy of loading time, accuracy of current time product, reproducibility of radiation output, linearity and consistency in radiography, half layer value in X-ray equipment, focal size and collimator, relationship between X-ray field and image reception area, consistency of light irradiation versus X-ray irradiation, performance of the mechanical device, focal spot to skin distance accuracy, image quality evaluation, and technical characteristic of cone-beam computed tomography) were selected for a total of 20 criteria.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2004.10a
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• pp.45-51
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• 2004