• Journal of the Korean Society of Safety
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• v.32 no.2
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• pp.59-65
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• 2017

Calculation of the damage impact of chemical accidents is an important element in site, and the initial isolation distance and the protective action distances are significant factors in coping the chemical accident. In this study, three major cities that represent each Province were selected, and the safety distances were calculated considering regional climate conditions. The results were compared with the prescribed values in Emergency Response Guidebook. It is concluded that the regional meteorological conditions such as temperature, vapour pressure, relative humidity, wind speed, and cloud cover should be reflected in estimating the initial isolation distance and the protective action distance.

• Korean Security Journal
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• no.2
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• pp.83-98
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• 1999

The LPG station's explosion at Bucheon city was a major accident which with rare frequency of occurrence but large damage effect. Therefore, to prevent similar accident in the future from LPG chargings stations which located at inner urban area, it needs to identify the damage effects of such facilities by comparing theoretically quantities risks-PHAST. The BLEVE effects from the accident showed similar level in case of heat flux, however, the over pressure level reflected at reduced distance. The structure damage to the nearby area showed comparatively large reduction of concrete strength and shape changes through by heat effect while the overpressure effect was small.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.3
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• pp.236-242
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• 2002

This paper presents some advanced and supplemental methods to enhance the accuracy In case of calculating geometric divergence attenuation, attenuation by multiple screening structures, ground attenuation at unflat surfaces of sound during propagation outdoors by the methods specified in ISO 9613-2. Moreover, a calculation method for considering short-term wind effect, specified in ASJ Model-1998, is also introduced. To verity the accuracy of adopted methods, we have carried out highway traffic noise prediction and measurement at tile twelve locations appearing representative road shapes and structures, such as flat, retained cut, elevated, barrier-constructed roads. From the results, we have confirmed the predicted results show good correspondence with the measured at direct, diffracted and reflected sound fields within 30 m from the center of near side lane.

• Journal of the Korean Society of Safety
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• v.19 no.3 s.67
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• pp.108-117
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• 2004

Dynamic analysis method is Presented for analyzing rectangular liquid storage structures excited by horizontal and vertical ground motions. The irrotational motion of invicid and incompressible ideal fluid in rigid rectangular liquid storage structures subjected to horizontal and vertical ground motions and the motion of fluid induced by structural deformation are expressed by analytic solutions. Analysis methods are obtained by applying analytic solutions of the fluid motion to finite element equation of the structural motion. The fluid-structure interaction effect is reflected into the coupled equation as added fluid mass matrix. The free surface sloshing motion, hydrodynamic pressure acting on the wall and structural behavior due to horizontal and vertical ground motions are obtained by the presented method.

• Clean Technology
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• v.8 no.2
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• pp.93-99
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• 2002

Adsorption dynamics for toluene and trichloroethylene with an isothermal fixed bed of activated carbon fiber were investigated. Equilibrium isotherms were measured by a static method for toluene and trichloroethylene onto activated carbon fiber at temperatures of 298, 323, and 348 K and pressure up to 3 kPa for toluene and 6 kPa for trichloroethylene, respectively. These results were correlated by the Toth equation. And dynamic experiments in an isothermal condition of 298 K were examined. Breakthrough curves reflected the effects of the experimental variables such as partial pressures for adsorbate and interstitial bulk velocities of gas flow. To present the column dynamics, a dynamic model based on the linear driving force (LDF) mass transfer model was applied.

• KIEE International Transaction on Systems and Control
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• v.2D no.2
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• pp.120-124
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• 2002

A new methodology is presented to diagnose faults in equipment plasma. This is accomplished by using neural networks as a pattern recognizer of radio frequency (rf) impedance match data. Using a match monitor system, the match data were collected. The monitor system consisted mainly of a multifunction board and a signal flow diagram coded by Visual Designer. Plasma anomaly was effectively represented by electrical match positions. Twenty sets of fault-symptom patterns were experimentally simulated with variations in process factors, which include rf source power, pressure, Ar, and $O_$2 flow rates. As an input to neural networks, two means and standard deviations of positions were used as well as a reflected power. Diagnostic accuracy was measured as a function of training factors, which include the number of hidden neurons, the magnitude of initial weights, and two gradients of neuron activation functions. The accuracy was the most sensitive to the number of hidden neurons. Interaction effects on the accuracy were also examined by performing a 2$^$4 full factorial experiment. The experiments were performed on multipole inductively coupled plasma equipment.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1869-1874
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• 2004

Acoustic pressure field around the cross-flow fan is predicted by a hydrodynamic-acoustic splitting method. Unsteady flow field is obtained by solving the incompressible Navier-Stokes equations using an unstructured finite-volume method on the triangular meshes, while the acoustic waves generated inside the cross-flow fan are predicted by solving the perturbed compressible equations(PCE) with a 6th-order compact finite difference method. Computational results show that the acoustic waves of BPF tone are generated by interactions of the blades wakes with the stabilizer, which then are reflected from the rear-guider and mainly propagate towards the fan inlet. Also, a directivity of BPF noise predicted by the PCE is noticeably different from that of the FW-H equations, in which a fan casing effect cannot be included.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.71-74
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• 2008

This paper aims at studying the key design elements for the optimal ventilation system design, developing the design models and suggesting the design guidelines. The key elements include the basic exhaust emission rate, wall friction coefficient, vehicle drag coefficient and slip streaming effect, jet fan operating efficiency, natural ventilation force and installation scheme for jet fans and ventilation monitors in tunnel. The design models developed in this study are one-dimensional ventilation simulator to analyze the air flow, pressure profile and pollutant dispersion inside and outside tunnel, expert model to choose the optimal ventilation method, and the ventilation characteristic chart to evaluate the preliminary ventilation system. The study results are reflected in the design guideline for road tunnel ventilation system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.237-243
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• 1997

Most outdoor sounds go from sources relatively near the ground to receivers near the ground. When either source or receiver are near the ground, interference can occur between the direct sound and that reflected at the ground which travels a slightly longer path. The sound pressure at the receiver is very different depending on the state of ground surface i.e. ground impedance. Ground impedances could be characterized by the value of a single parameter, namely the flow resistivity of the ground surface. This study suggests the measurement method of the flow resistivity using two microphones and predicts the flow resistivities of various ground surfaces.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.59-65
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• 2005

The research is an objective which prevents a construction noise by developing prediction program on utility, helps comprehension of construction noise by case study. The program developed with Visual Basic of the Excel Logic. The standard noise is a data with report of the construction machine (National Institute of Environmental Research), construction noise of sound pressure level applied the distance decrease of the point source. The decrease effect of the barrier noise wall used the data of 5, 10, 15, 20dB where the diffraction is reflected. used a program, case study is suggested Prevention method to prevent noise of construction site.