• Proceedings of the Korean Fiber Society Conference
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• 한국섬유공학회 1996년도 추계 학술발표회
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• pp.29-34
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• 1996

In the present paper, the flow distribution in the hot air drying chamber of a sizing machine was numerically analyzed with respect to the geometries of the intake duct to obtain the more uniform flow distribution in the chamber. The result shows that the velocity distribution in the inlet of the chamber was significantly dependent on the the geometry of the intake duct. The degree of the non-uniformity in the chamber was reduced as the incident angle of the intake duct became to be smaller.

• Bulletin of the Korean Space Science Society
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• 한국우주과학회 2004년도 한국우주과학회보 제13권2호
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• pp.356-359
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• 2004

Prelaunch thermal analysis of the KSLV (Korea Space Launch Vehicle)-I PLF (Payload Fairing) was performed to predict maximum/minimum liftoff temperatures and to evaluate of air conditioning performance. Prelaunch thermal analysis includes internal air conditioning effect, external convective heating/cooling, radiation exchange with the ground and sky, radiation between spacecraft and PLF, and solar radiation incident on PLF. Analysis was performed at two extreme conditions, hot day condition and cold day condition. The results showed that the maximum liftoff temperature was $53^{\circ}C$ and the minimum liftoff temperature was $-3.8^{\circ}C$. It was also found that conditioned air supplying, in $20{\pm}2^{\circ}C\;and\;1200\;m^3/hr$, is sufficient to keep the internal air in required temperature range.

• Proceedings of the KSR Conference
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.1-6
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• 2005

To improve safety management of railway and cope with the factors to threat technical and social safety, we need to establish railway safety management system based on analysis of hazards and assessment of risk for railway system. So we have to conduct PHA(Preliminary Hazard Analysis) first to understand weak points and factors to possibly threat safety using analysis of related data such as past accident/incident data and safety regulation and classification standards of hazards/causes of railway accidents. Therefore in this research, we led types/dangerous events/causes of risks/factors of risks from hazard log developed based on railway accident classification and hazards of railway accident. PHA model for domestic railway system will be used in risk analysis and risk assessment of railway accident.

• Journal of the Korean Society for Aviation and Aeronautics
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• 제28권4호
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• pp.21-31
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• 2020

There are two to three helicopter accidents every year in Korea, representing 5.7 deaths per 100,000 flights. In this study, an analysis was conducted on helicopter accidents that occurred in Korea from 2005 to 2017. The accident analysis was based on the aircraft accident and incident report published by the Aircraft and Railway Accident Investigation Board. This Research analyzed the characteristics of accidents occurring in Korea caused by human error by pilots. Accident analysis was done by classifying the organization, flight mission, aircraft class, flight stage, accident cause, etc. Pilot's huan error was classified as Skill-based error, decision error and perceptual error in accordance with the HFACS taxonomy. The accidents caused by pilot's human error were classified into five categories: powerlines collision, loss of control, fuel exhaustion, unstable approach to reservoir, and elimination of tail rotor.

• Agribusiness and Information Management
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• 제9권1호
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• pp.23-36
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• 2017

The incidents of garbage dumplings in 2004 and the report on giant castella are the examples that shows how big the influence of broadcasting on the industry is. There were discussions on the importance of securing the objectivity of broadcasting, however, the existing related researches have lacked the analysis of actual proof for the influence of broadcasting contents, and as that of the law and system was confined to theoretical arguments, there were not enough suggestions for realistic alternatives. In this paper, we will examine the influence of broadcasting contents on the food industry through an analysis of actual proof, and propose alternatives in terms of the law and policy for securing the objectivity and fairness of broadcasting, to solve this problem.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제24권6호
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• pp.644-653
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• 2013

In this paper, a formulation for obliquely incident electromagnetic wave has been presented for an analysis of highpower electromagnetic pulse penetration into multilayered dispersive media. Based on generalized models of measured dielectric constants and propagation channels reflecting the Earth's general features, the propagation phenomenon of the obliquely incident early-time(E1) high altitude electromagnetic pulse(HEMP) is analyzed. In addition, the polarization and critical angle are also considered. It is found that the total reflection occurs at an incident angle of about 38 degrees at the soil-rock interface, and that the parallel-polarized E1 HEMP penetrates better than the perpendicular-polarized one. The peak level of the penetrating electric field is found to be 5.6 kV/m at normal incidence, regardless of the type of polarization, and E1 HEMP is greatly reduced near the critical angle. Moreover, the penetrating E1 HEMP is analyzed as a variation of moisture content and depth of materials, resulting E1 HEMP could be useful in determining the levels of shielding required for buried facilities.

• Journal of the Korea Institute of Information Security & Cryptology
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• 제23권3호
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• pp.515-530
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• 2013

The results of investigations into marine incidents have become an important basis in determining not only possible causes, but also the extent of negligence between the perpetrator and victim. However, marine incidents occur under special circumstances i.e. the marine environment, and this leads to difficulties in identifying causes due to problems in scene preservation, reenactment and acquisition of witnesses. Given the aforementioned characteristic of marine incidents, the International Convention for the Safety of Life at Sea (SOLAS) has adopted mandatory regulations on the carriage of Voyage Data Recorders (VDRs) and Automatic Identification Systems (AIS) for ships of a certain gross tonnage and upwards, so as to reflect recent developments in radio communication and marine technology. Adopted to provide an international standard for investigations and to promote cooperation, the Code of the International Standards and Recommended Practices for a Safety Investigation into a Marine Casualty or Marine Incident (Casualty Investigation Code) recommends member states to build capacity for analysis of VDR data. Against this backdrop, this paper presents methods for efficient investigations into the causes behind marine incidents based on data analysis of VDR, which serves as the black box of ships, as well as digital forensic techniques.

• Transactions of the Korean hydrogen and new energy society
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• 제23권6호
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• pp.588-597
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• 2012

In the present study, the dispersion characteristics of hydrogen leakage from a Fuel Cell Vehicle (FCV) were analyzed by numerical simulation in order to assess the risk of a hydrogen leakage incident in a long road tunnel. In order to implement the worst case of hydrogen leakage, the FCV was located at the center of a tunnel, and hydrogen was completely discharged within 63 seconds. The Leakage velocity of hydrogen was adopted sub-sonic speed because that the assumption of the blockage effect of secondary device inside a vehicle. The temporal and spatial evaluation of the hydrogen concentration as well as the flammable region in a road tunnel was reported according to change of ventilation operating conditions. The hydrogen was blended by supply air form a ventilation fan, however, the hydrogen was discharged to outside in the exhaust air. It is observed that the efficiency way to eliminate of hydrogen is supply air operating condition under the hazardous hydrogen leaking incident. The present numerical analysis can be provided useful information of ventilation under the hydrogen leaking situation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제15권2호
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• pp.65-70
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• 2015

In this paper, the solutions of TE (transverse electric) scattering problems by a conductive strip grating over grounded two dielectric layers are analyzed by applying the PMM (point matching method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, the scattered electromagnetic fields are expanded in a series of Floquet mode functions, and the conductive boundary condition apply to analysis of conducting strip. The most normalized reflected powers of the sharp variations in minimum values are scattered in direction of the other angles except incident angle. The numerical results for normalized reflected power are analyzed by according as the width and spacing of conductive strip, the relative permittivity and thickness of the two dielectric layers, and incident angles. The numerical results of present numericl analysis are shown in good agreement compared to those of the existing papers using FGMM (fourier galerkin moment method).

• Fire Science and Engineering
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• 제24권2호
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• pp.9-20
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• 2010

This study indicates direction on establishment of the operational plan for disaster mitigation and its implementation for maintaining business continuity of the local company of the first step, and seeks plans for maintaining their continuity through the establishment of early counter system constructed for achieving lasting safe at the any disaster. For achieving it, we investigated the standard of disaster management selected by the government called "Incident Preparedness and Operational Continuity Plan" Guideline, and investigated a guideline to be easily applied to domestic companies. And, we also studied on how to build the operational plan of disaster mitigation and apply IT techniques to A corporation. Especially, this study indicates the models of establishment of risk assessment, impact analysis, prevention and mitigation plan, response management plan for the establishment of plan among 5 main steps on "Incident Preparedness and Operational Continuity Management" Guideline. We devised the plan to activate the disaster mitigation activity throughout the country. It shows the skills to be prepared to upgrade the level of disaster response in this study.