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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society of Safety
Journal Basic Information
Journal DOI :
The Korean Society Safety
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Volume & Issues
Volume 22, Issue 6 - Dec 2007
Volume 22, Issue 5 - Oct 2007
Volume 22, Issue 4 - Aug 2007
Volume 22, Issue 3 - Jun 2007
Volume 22, Issue 2 - Apr 2007
Volume 22, Issue 1 - Feb 2007
Selecting the target year
Theoretical Analysis of Geared Dynamic Characteristics in a Torsional System
Cho, Sung-Min ; Ahn, Min-Ju ; Son, Yu-Sun ; Yoon, Jong-Yun ; Lyu, Sung-Ki ;
Journal of the Korean Society of Safety , volume 22, issue 1, 2007, Pages 1~6
In the field of the system dynamics related to the vibration characteristics, there are lots of examples introduced for the translational system, however the analysis of the torsional systems such as driveline in the automobile is rare compared with the translational system. The purpose of this study is to show the simple concepts for the torsional system analysis and explain how to adjust the mathematical methods for the geared motions, which can be applied to the driveline of the automobile. In order to do it, there are several systematical approaches described about how the sub-system motions can be understood with the mathematical descriptions. Based upon this fundamental study, several torsional system modeling methods will be suggested. Therefore, the characteristics of the torsional system and the gear motions will be explained, which can be adjusted in a further study as a next step.
An Improvement Study on National Fire Safety Code of Sprinkler System for Hydraulic Calculation Application
Lee, Keun-Oh ; Kang, Joo-Hyeong ;
Journal of the Korean Society of Safety , volume 22, issue 1, 2007, Pages 7~12
There are two kinds of design process for sprinkler system. one is pipe schedule system and the other is hydraulically designed system. We have inefficient results when we design by hydraulically designed system because the design process for sprinkler system is restricted by domestic fire code. Therefore, it is essential to do an introduction of hydraulically designed system which is based on engineering for enhancing reliability and efficiency of sprinkler system. This study presents points at issue by comparing and studying design standards of sprinkler system from Korea, Japan and NFPA, and presents improvement plans of national fire safety code of sprinkler system by processing, comparing and analyzing designs according to piping schedule and hydraulically designed system about domestic objects. Installation standards of sprinkler system have to be applied not by object buildings but by hazard classification. It is hard to design an efficient sprinkler system for fire control when water supply requirement of sprinkler systems allocated according to a size of a building because the same purpose but other buildings may request more water requirement or less. We should sublate the pipe schedule system from national fire safety code and need to introduce the hydraulically designed system. The pipe schedule system presents easy access because it is based on the forecasted engineering calculations but it is applied to only small buildings like NFPA due to its low reliability.
A New Proposal for the Allowable Local Thickness of Straight Pipes in ASME Code Case N-597-2
Park, Jai-Hak ; Shin, Kyu-In ; Park, Chi-Yong ; Lee, Sung-Ho ;
Journal of the Korean Society of Safety , volume 22, issue 1, 2007, Pages 13~18
Structural integrity assessment of thin-walled pipes and pipe items has become one of the major issues in the nuclear power plant. ASME Section XI Code Case N-597-2 provides a criterion for acceptance of the pipes. But the code case has several limitations for application and sometimes gives too conservative or non-conservative results. So it is necessary to understand fully the technical bases of the code case. In the code case N-597, the allowable local thicknesses of thinned straight pipes are given for three different cases. Because of the different technical base, each case gives different thickness values and sometimes gives contradictory values. In this paper attempts were made in order to propose a unified rule for the allowable local thickness and in order to remove or relax the restrictions on the application of the code case. For this purpose elastic stress analyses were made using the finite element method and the stress results were examined. Based on the obtained bending stress results, a very simple procedure was proposed to obtain the consistent allowable local thickness for the thinned straight pipes.
A Study on the Residual Stresses of Ceramic Coating
Han, Ji-Won ;
Journal of the Korean Society of Safety , volume 22, issue 1, 2007, Pages 19~23
The aim of this study was to determine residual stresses in thermal barrier coatings(TBCs) by isothermal heating. Specimens were heated at the range of
. A finite element method was used to determine the residual stresses. Finite element coupled heat transfer and elastic-plastic thermal stress analysis using a general purpose commercial FEM software ABAQUS. I obtained the stresses were not affected below the temperature of
but affected over that of temperature.
A Study on Enhancement of UV Disinfection System Performance by the Vortex Generator
Kim, Bong-Hwan ; Ahn, Kook-Chan ; Kim, Dong-Jin ;
Journal of the Korean Society of Safety , volume 22, issue 1, 2007, Pages 24~29
The effectiveness of a UV(ultra violet) disinfection system depends on the characteristics of the waste water, flow conditions, the intensity of UV radiation, the amount of time the microorganisms are exposed to the radiation, and the reactor configuration. The wast water flow conditions are important factors in the design of UV disinfection system from the point of enhancement view of UV disinfection. The turbulent energy intensity in the wake by the vortex shedding are effective for UV radiation. Therewith the effectiveness of vortex generator is considered as a enhancement of UV disinfection. The experimental results presented give important evidences and explain that it is possible to predict UV disinfection performance based on flow experiments. An experimental investigation of two types of the vortex generator is presented. The qualitative and quantitative evaluations of the wake are made by flow visualization using smoke wire method and the measurement of vortex frequencies in the wind tunnel. From the experiment, following results were obtained that the delta wing type vortex generator is more effective than circular type because of the higher vortex frequencies and the smaller drag.
Development of Noise Evaluation Simulation Tool for Factory Design
Kim, Tae-Gu ; Lee, Hyung-Won ; Jeong, Dae-Up ;
Journal of the Korean Society of Safety , volume 22, issue 1, 2007, Pages 30~35
With the rapid industrialization and civilization development, noise has become a major problem in cities and is a very serious issue for the environment. Noise induced in a factory has a bad influenced on operation efficiency, accuracy and detail of work. The purpose of this paper is to develop a new noise evaluation software for predicting acoustic condition including noise properties during the design of a factory. Majority of commercial softwares for this purpose have been developed in foreign countries and they are quite expensive and hard to use. A new home-made software tool has been developed in the present work, which aimed at providing a more user-friendly environment. The tool developed in this work consists of four major part; the prediction and evaluation of noise in system design, database design, noise analysis development and 3D graphic modeling. The outcome of present work is expected to provide domestic users with a more user-friendly and economic acoustic design tool.
A Study on Minimum Ignition Energy by Controlled Discharge Energy
Choi, Sang-Won ; Ohsawa, Atsushi ;
Journal of the Korean Society of Safety , volume 22, issue 1, 2007, Pages 36~39
It is important to know Minimum Ignition Energy(MIE) of flammable materials for ignition hazard of chemical processes etc.. Currently a capacitor discharge is used mainly to measure the MIE. Then, it is impossible to control actively discharge energies and discharge time because the MIE measurement uses a high voltage capacitor and fixed capacitor. However, the control of discharge energy and discharge time will be convenient if self-sustain discharge is used. In this paper, we measured the MIE by self-sustain discharge of a pulse shape to propose the new measuring method of the MIE. AS a result, ignition energies are increased gradually as discharge duration time gets longer, and discharge current grows larger. Also, an arc discharge and a glow discharge occurred during the experimental period, and the ignition by glow discharges happened when discharge duration time was
, discharge current was 8A and 1A Especially, the MIE occurred the 0.05mm and 0.08mm of the gap distance between discharge electrode in the same discharge duration time.
Evaluation on Electric Shock Risk due to the Electric Potential Distribution in Bathtub
Kim, Chong-Min ; Kim, Han-Sang ; Kim, Sung-Chul ; Kim, Doo-Hyun ;
Journal of the Korean Society of Safety , volume 22, issue 1, 2007, Pages 40~46
It is evaluated that electric shock risk in bath so that we made and designed a bathtub which is the same size in real public bath. And then, we did an experiment, provided of electric leakage in various conditions, so we measured how to form an electric potential and knew the electric potential is formed variously under exposed conductor in bath. Also, we made certain that electric shock risk is down if we insert an insulated pipe in bathtub pipe which is prevent from being formed the electric field sharply. The results show that the increased shock risk and safe distance are estimated by the bathtub of limited width and depth, and the voltage simulated on the basis of Flux 3D concept is compared with the measured value.
A Study on the Stress Evaluation for Steel Box Girder Support Diaphragm
Kim, Doo-Hwan ; Park, Woo-Young ;
Journal of the Korean Society of Safety , volume 22, issue 1, 2007, Pages 47~53
A study is carried out to evaluate the stresses for steel box girder support diaphragm using finite elements method. This study includes the stress characteristic compared with experimental method for diaphragm design. The results from the finite elements method are compare with the results from experimental investigations and shown to give good agreement. The shear stresses were generally uniformed in the outer plane. increased rapidly above the bearing. The horizontal direct stresses were generally low except in the vicinity of the bearing and opening comer where a local increase in compressive stresses occured.
A Case Study on the Slope Reinforcement by Improved Steel Pipe Nailing
Choi, Dong-Nam ; Lim, Heui-Dae ; Song, Young-Su ; Lee, Kyu-Hwan ;
Journal of the Korean Society of Safety , volume 22, issue 1, 2007, Pages 54~60
This paper describes typical design and construction practice for in-situ ground reinforcement technique using improved steel pipe pressure grouting. A case history is presented to illustrate the benefit gained by application of the technique. This technique was applied to cut slopes developed in the construction of auxiliary spillway of 00 dam. Applicable conditions, method of survey, slope stability analysis and construction are given in this parer. As for the construction method, a procedure is given and the main points are the control of construction work. As a result of the pull-out test, it is shown that seel pipe nailing is particularly useful for stabilizing rock slope.
Estimation of Car Driver Error Probabilities Through Driver Questionnaire
Lee, Jae-In ; Lim, Chang-Joo ;
Journal of the Korean Society of Safety , volume 22, issue 1, 2007, Pages 61~66
Car crashes are the leading cause of death for persons of every age. Specially, human-related factor has been known to be the primary causal factor of such crashes than vehicle-and environmental-related factors. There are various studies to analyze driver's behavior and characteristics in driving for reducing the car crashes in many areas of car engineering, psychology, human factor, etc. However, there are almost no studies which analyze mainly the human errors in driving and estimate their probabilities in terms of human reliability analysis. This study estimates the probability of human error in driving, i.e. driver error probability. First, fifty driver errors are investigated through DBQ (Driver Behavior Questionnaire) revision and the error likelihoods in driving are collected which are judged by skillful drivers using revised DBQ. Next, these likelihoods are converted into driver error probabilities using the results that verbal probabilistic expressions are changed into quantitative probabilities. Using these probabilities we can improve the warning effects on drivers by indicating their driving error likelihoods quantitatively. We can also expect the reduction effects of car accident through controlling especially dangerous error groups which have higher probabilities. Like these, the results of this study can be used as the primary materials of safety education on drivers.