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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 23, Issue 6 - Dec 2008
Volume 23, Issue 5 - Oct 2008
Volume 23, Issue 4 - Aug 2008
Volume 23, Issue 3 - Jun 2008
Volume 23, Issue 2 - Apr 2008
Volume 23, Issue 1 - Feb 2008
Selecting the target year
Development of Multi Channel Gas Leakage Detector for Large Facility
Jeong, Kyu-Won ;
Journal of the Korean Society of Safety , volume 23, issue 3, 2008, Pages 1~7
As a clean fuel, LNG or LPG is widely used in large restaurants or plants instead of coal. These fuels are easy to use and cheap. However, they are inflammable very much and easily exploded at the worst. So there are many laws and regulations legislated for the handling and usage of the gas facilities. Nevertheless, very harsh explosions occurred in several domestic or foreign places. In this paper a gas detection and alarm system was developed for large facilities. A new concept for connecting many gas detectors was proposed and based upon that a system including hardware and software have been developed and tested. Although up to 16 gas detectors apart 1 km from main controller can be connected currently, this system can be easily expanded for more detectors because each gas detector receiver communicates with main controller using industrial standard RS-485 multi drop technique. Furthermore several additive functions was included for the installation and maintenance convenience.
Residual Stresses Analysis of Ceramic Coating Materials
Han, Ji-Won ;
Journal of the Korean Society of Safety , volume 23, issue 3, 2008, Pages 8~11
In the present work, the measurement method of residual stresses in thermal barrier coatings(TBCs) which are received the thermal shock is performed numerically. For this, the internal residual stresses are predicted by commercial FEM software ABAQUS because the hole drilling strain gage method measures residual stresses only near the surface of a material. As the results of this study, the residual stresses are linearly increased when the surface temperatures are over
. It is also found that the values of residual stress are increased as the coating thickness is thin.
A Study on Fatigue Strength of Austenitic Stainless Steel for Centrifuge
Lee, Mee-Hae ; Kim, Yong-Soo ; Park, Joon-Woo ;
Journal of the Korean Society of Safety , volume 23, issue 3, 2008, Pages 12~16
For industrial centrifuges, the state of their welding areas, even with a naked-eye observation, offers potential safety problems such as inconsistent bead formation. STS304, which is used mainly in centrifuges, is made of metal alloys with chrome and nickel as the main ingredients, offering excellent corrosion resistance, thermal resistance, and high strength, and thus allowing it to be used for diverse purposes. This paper conducted tensile and fatigue tests of STS304 to improve the safety of centrifuges. In the findings, for the static behavior of the STS304 material, welded specimens increased their yield and tensile strength compared with the base test specimens, but decreased their elongation ratio. Also, the data dispersion phenomenon of welded specimens remarkably increased.
Evaluation of Plastic Collapse Bending Load of Elbows with Thinning Area of Various Shapes
Shin, Kyu-In ; Lee, Sung-Ho ; Yoon, Kee-Bong ;
Journal of the Korean Society of Safety , volume 23, issue 3, 2008, Pages 17~24
Elbows with various shapes of local wall thinning were numerically analyzed by finite element method to get load-displacement curves and the maximum loads. Results were compared with the experimental data obtained by another study. Elastic-plastic analysis were carried out under the combined loading conditions of internal pressure and in-plane bending loads. Two types of bending loads were considered such as elbow opening mode and elbow closing mode. Also, two different wall thinning geometries were modeled. Wall thinning area located extrados or intrados of elbow inner surface was considered. Longitudinal and circumferential lengths of the thinning area and the thinned thickness were varied for analysis. The results showed that the maximum load of the wall-thinned elbow decreased with increasing of the circumferential thinning length and the thinned thickness in both of extrados and intrados thinning locations in both loading types. The maximum load obtained by the analysis were in good agreement with the experimentally measured maximum load with the same wall thinning type and dimensions. This supports accuracy of the analysis results obtained in this study.
Thermal Stress Analysis of Ventilated Disc Brake
Kim, Yang-Sul ; An, Su-Chul ;
Journal of the Korean Society of Safety , volume 23, issue 3, 2008, Pages 25~29
In automotive disc brake system, friction heat is not uniformly distributed due to various reasons such as thermal expansion and imperfections in geometry. It is well known that thermoelastic distortion due to fictional heating affects the contact pressure distribution and can lead to thermoelastic instability, where the contact load is concentrated in one or more small regions on the brake disc surface. These regions then take very high temperatures and passage of hot spots moving under the brake pads can cause low frequency vibration called brake judder. This paper presents the FEM(finite element method) result for the temperature distribution of ventilated disc brake. A steady state two-dimensional model of disc brake system predicts the surface temperatures during a multi-stop driving schedule.
An Experimental Investigation on Combustion Characteristics of the Knockdown Building
Lee, Jung-Yun ; Kim, Hong ;
Journal of the Korean Society of Safety , volume 23, issue 3, 2008, Pages 30~35
The recent fire incident in an elementary school of Chonan city causes the media focus on the fire safety of residential container buildings. In this study, real fire tests were conducted in this kind of buildings. Combustion products including
, HCI, HCN were measured, in order to investigate the hazard-reduction effects of employing gas mask protected with filter during the fire emergency of residential container buildings. According to the test results, whether or not employing the filter showed a sheer difference in the toxicity of the fire-induced gases, and then the importance of wearing a gas mask was evidently demonstrated.
The Compatibility of MSDS through the Investigation of the Combustible Properties for MEK
Ha, Dong-Myeong ;
Journal of the Korean Society of Safety , volume 23, issue 3, 2008, Pages 36~41
For the safety design and operation of many chemical process, it is necessary to know certain explosion limit, flash point and autoignition temperature(AIT) of handling substances. Also it is necessary to know explosion limit at high temperature and pressure. For the safe handling of MEK(methyl ethyl ketone), explosion limit at
and the temperature dependence of the explosion limits were investigated. And flash point and AIT for MEK were experimented. By using the literatures data, the lower and upper explosion limits of MEK recommended 1.8 vol% and 11.0 vol%, respectively. In this study, measured the lower and upper flash points of MEK were
, respectively. This study measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for MEK, and the experimental AIT of MEK was
. The new equations for predicting the temperature dependence of the explosion limits of MEK is proposed. The values calculated by the proposed equations were a good agreement with the literature data.
An Experimental and Analytical Study on Shear Transfer for Safety Evaluation of Concrete Structure
Kim, Kwang-Soo ;
Journal of the Korean Society of Safety , volume 23, issue 3, 2008, Pages 42~50
This study, push-off tests for the initially uncracked specimens were conducted to investigate shear transfer mechanism in reinforce concrete elements. Experimental programs for shear transfer were undertaken to investigate the effect of the concrete compressive strength, the presence of steel stirrups as shear reinforcement and the amount of steel stirrups. As the shear plane is loaded, several cracks form in a direction inclined to the shear plane, creating compression struts in the concrete. For this stage, shear is being transferred through a truss-like action produced by the combination of the compressive force in the concrete struts and the tensile force that the steel reinforcement crossing the shear plane develops. In the normal strength concrete specimens with steel stirrups, ultimate failure occurred when the compression struts crushed in concrete. In the high strength concrete specimens, on the other hand, ultimate failure occurred when the steel stirrups developed their yield strength.
The Evaluation of Compressive Strength in Cement Mortar using Electromagnetic Properties
Kim, Dong-Baek ; Kwon, Seung-Jun ;
Journal of the Korean Society of Safety , volume 23, issue 3, 2008, Pages 51~57
NDT(Non-Destructive Testing Evaluation) using electromagnetic(EM) properties can be used for evaluation of physical performance in cement-based materials. In this study, a technique for strength evaluation in cement mortar is proposed through the measured EM properties(conductivity and dielectric constant). For this research, cement mortar specimens with 5 W/C ratios are made for evaluation of compressive strength and they are also utilized for tests of EM properties in the range of
frequency considering exposure condition and curing period. The averaged conductivity and dielectric constant in
frequency are reduced to
, respectively with increasing water to cement ratios. Through the linear regression analysis, relationships between EM properties and results from the compressive strength are obtained, which shows higher correlated factor(
) in the specimens exposed to room condition. The gradients in dielectric constant for strength results is measured to be higher than those in conductivity by
times. The results from dielectric constant in room condition shows the most efficient relation for evaluation of strength.
Evaluation of Structural Performance on Corbel in the Reinforced Concrete
Cho, Seong-Ho ; Park, Tae-Won ; Woo, Sung-Sik ; Chung, Lan ; Park, Hyun-Soo ; Kim, Dong-Baek ;
Journal of the Korean Society of Safety , volume 23, issue 3, 2008, Pages 58~64
In order to identify the exact behavior of corbel section, the horizontal force acting on corbel section should be considered as well as the vertical force. In this study, a new corbel section, which is economical and easy to construct, is developed by evaluating the exact strength of the section. Experiments were performed to verify the strengths of the proposed sections comparing with those of the currently used section. The summary of the experiment results are as follows: 1) In order to minimize the horizontal force effect, it was found that the use of pre-stressing was most effective, and that TB type corbel section is a most efficient section in terms of economy and workability. 2) The experimentally obtained strength of corbel section matched well with that estimated using shear friction theory. Therefore, it is concluded that shear friction theory would be very useful if a precise crack angie in the corbel section, which is pre-stressed by PS strings and threaded bolts, is available.
Variation of Relative Power Characteristics in EEG while Inducing Human Errors
Lim, Hyeon-Kyo ;
Journal of the Korean Society of Safety , volume 23, issue 3, 2008, Pages 65~70
Electroencephalogram(EEG) would be the most objective psychophysiological research technique on human errors though few research has been taken yet. This study aimed to get characteristics of human error while committing simple Odd-Ball tasks by utilizing the power spectrum technique of EEG data. Each experiment was composed of 3 tasks with different rules, and three young undergraduate students participated in this study as paid subjects. The result showed that subject and the interaction of subject and task factors were statistically significant on variation of power of
bands which implied there would exist groups with homogeneity in their response. And though the variation of band powers due to task factors were not so great as to get statistical significance, it implied that the task requiring decoding process would be more strange to human beings than the task merely requiring psychological recall process.
Identification of Age Threshold for Driving Performance
Kim, Tae-Ho ; Ko, Joon-Ho ; Won, Jai-Mu ; Hu, Ec ;
Journal of the Korean Society of Safety , volume 23, issue 3, 2008, Pages 71~78
This study aims to identity the age group where driving performance significantly decreases based on the data collected from the Korea Transportation Safety Authority's driver aptitude tests in 2006. The test includes following six driving simulator-based tests: estimation of moving objects' speed, estimation of stopping distance, three tests for drivers' multi-task ability, and kinetic depth perception. These six test results were utilized for the identification of the age threshold applying the CART technique, suggesting driving ability significantly be decreased over 50s. This finding was confirmed by two analyses using the accident history data containing the information of accident and non-accident drivers and the degree of accident severity. The results of this study imply that accident prevention efforts should be enhanced over a wider range of age group than the current practice where the age of 65 is generally applied for the threshold dividing senior and non-senior driver groups.
A Study of Adverse Health Symptoms of Spray Painters Using Isocyanates(HDI)
Lee, So-Gil ; Pisaniello, Dino ; Lee, Nae-Woo ;
Journal of the Korean Society of Safety , volume 23, issue 3, 2008, Pages 79~86
In the manufacturing industries using HDI(hexamethylene diisocyanate) product hardeners, exposure to HDI is common to spray painters in terms of inhalation and dermal or ocular contact. Due to a lack of information for spray painters in automobile and furniture industries, a questionnaire survey was conducted for the prevalence of adverse health symptoms(33 spray painters and an unexposed group n = 91) to assess the importance of personal controls. Despite the small sample size, common health symptoms were reported, such as skin symptoms(dry cracked skin-61% and dermatitis/skin irritation-33%) and respiratory symptoms(phlegm-49%, asthma-21%). In addition, other adverse health symptoms were reported, such as skin rash(12%), cough(39%), shortness of breath with wheezing(30%), chest tightness and difficulty in breathing(30%). No significant eye symptoms were reported. It was founded that the adverse health symptoms reported in this study were related to poor personal work practices and inappropriate PPE use. Therefore, appropriate personal controls like PPE use, work practices, regular training and education are suggested to minimize the risk of health symptoms. In addition, medical examination will also be suggested for individual health effects.
An Application of Time Discontinuous Finite Element Method for Heat Conduction Problems
Kim, Chi-Kyung ;
Journal of the Korean Society of Safety , volume 23, issue 3, 2008, Pages 87~92
A finite element method which is discontinuous in time is developed for the solution of the classical parabolic model of heat conduction problems. The approximations are continuous with respect to the space variables for each fixed time, but they admit discontinuities with respect to the time variable at each time step. The method is superior to other well-known approaches to these problems in that it allows a wider range of moving boundary value problems to be dealt with, such as are encountered in complex engineering operations like ground freezing. The method is applied to one-dimensional and two-dimensional heat conduction problems in this paper, although it could be extended to more higher dimensional problems. Several example problems are discussed and illustrated, and comparisons are made with analytical approaches where these can also be used.