Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Society of Safety
Journal Basic Information
Journal DOI :
The Korean Society Safety
Editor in Chief :
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
An Experimental Study for the Effect of Ventilation Velocity on Performance of a High Pressure Water Mist Fire Suppression System
Kim, Dong-Woon ; Bae, Seung-Yong ; Ryou, Hong-Sun ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 1~6
This experiments are perfol1ned to investigate the effect of ventilation velocity on a high pressure water mist tire suppression in train. The experiment is conducted in half scale modeled train of a steel-welled enclosure (5.0m
2.2m). The ventilation velocity is controlled by the ventilation duct through an inverter in the range of 0 to 3m/s. The coverage-radius and an injection angle of an high pressure water mist system are measured. The mist nozzle with 5-injection holes is operated with pressure 60bar. The heptane pool fires are used. The fire extinguishment times and the temperature are measured for the ventilation velocities. In conclusion, because the momentum of injected water mist is more dominant than that of ventilation air, the characteristics of water mist, the fire extinguishment times and the temperature are affected very little by ventilation velocity.
A Study on the Ultrnsonic Distance Amplitude Characteristics Curve for Weld Defects Evaluation of Titanium Weld Zone
Yi, Won ; Park, Hee-Dong ; Yun, In-Sik ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 7~12
This study proposes integrity evaluation method of weld zone in titanium using titanium distance amplitude characteristics curve(TDACC) and ultrasonic signals. For these purposes, the ultrasonic signals for porosity defects of weld zone in titanium are acquired in the type of time series data and echo strength. 4 lines in the DACC indicated damage evaluation standard of weld zone in titanium. The acquired ultrasonic signals agree fairly well with the measured results of reference block and sensitivity block(defect location, bean1 propagation distance, echo strength, etc). The proposed TDACC in this study agree fairy well with the measured results of weld zone in titanium(weld defects as porosity). The proposed TDACC in this study can be used for integrity evaluation of weld zone in titanium.
A Study on the Concave and Pressure Angle Error of Gear Finish Roll Forming
Jang, J.H. ; Kim, J.S. ; Bae, H.J. ; Uematsu, S. ; Cho, S.H. ; Lyu, S.K. ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 13~18
This study deals with finish roll forming by forced displacement can be conceived as a method of eliminating errors in conventional form rolling under constant loads. This method produces a high-precision tooth profile by low-speed form rolling when a high rigid screw or cam is used at the pressurized section. Tooth profile is decided in the beginning of roll forming and
mainly increases if the number of roll forming process is increased. Gear class is improved by one or two class after roll forming if the gear has convex type error and pressure angle error in KS 4 class. If the gear have concave type error and pressure angle error and pressure angle error, gear class is not improved in theory, but improved a little in practice. In the finishing roll forming, it inevitably yields both the concaving of tooth profile and plastic deflection of addendum of teeth. Experiments show that the concaving and the plastic deflection are successfully reduced, the accuracy of tooth profile reaches to KS 0 class.
The Static Strength Analysis of Prying Action for T-flange Shape Structure Using F10T High Strength Bolt
Park, Myung-Kyun ; Lee, Joong-Won ; Koo, Bon-Sung ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 19~24
This paper presents and discusses the experimental results on the F10T high strength bolts used in the T-flange joint structure. The experimental works were carried out for the parameters which are flange web thickness, the distance between bolts, prying ratio. The results show that the working stress imposed to bolts decreases as the flange web thickness increases on the other hand the imposed stress to the bolts increases as the distance between two bolts increases. In other words the strength of the T-flange joint increased as the web flange thickness increases and the distance between two bolts decreases. The prying ratio is increased as the distance between two bolts increases and as the flange web thickness decreases However, the degree of stress decrease in flange thickness variation is not that high as the distance variation between two bolts. Finally the equation for predicting the failure stress in T-flange joint structure using F10T high strength bolts was suggested.
The Evaluation of Crack Propagation in Functionally Graded Materials with Coatings
Kwon, Oh-Heon ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 25~29
Recently, new functionally graded material(FGM) that has a spatial variation in composition and properties is developed because of its good quality. This material yields the demands for resistance to corrosion and high temperature in turbine blade, wear resistance as in gears and high strength machine parts. Especially coating treatment in FGM surface brings forth a mechanical weak at the interface due to discontinuous stress resulting from a steep material change. It often, leads cracks or spallation in a coating area around an interface. The behavior of propagation cracks in FGMs was here investigated. The interface stresses were reduced because of graded material properties. Also graded material parameter with exponential equation was founded to influence the stress intensity factor. And the resistance curve with FGM coating was slightly increased.
Assessment of Grid Sensitivity in the FDS Field Model to Simulate the Flame Propagation of an Electric Cable Fire
Kim, Sung-Chan ; Lee, Seong-Hyuk ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 30~35
The present study has been conducted to examine the effect of grid resolution on the predicted results for electric cable fire using pyrolysis model in FDS(Fire Dynamics Simulator, version 5). The grid independent test for different grid resolutions has been performed for a PE coating cable and the grid resolution is defined by the non-dimensional characteristic length of fire and mean grid size. The calculated maximum heat release rate and mean flame spread rate were almost constant for higher grid resolution of 20
25 and the computing time for the grid resolution takes approximately 20hours to solve flame propagation with pyrolysis model. The geometrical simplification of a electric cable dose not greatly affect on the maximum heat release rate and flame spread rate and the rectangular approximation of cable shape gives acceptable result comparing with the round cable with stepwise grid.
A Study on Back EMF of BLDC Motor Using Numetical Analysis Method
Kim, Hyun-Cheol ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 36~41
This report describes the analytical solution of back EMF for BLDC motor using numerical analysis of air gap flux density. The analysis of air gap flux density is the key to expect the performance of back EMF for the design of brushless motor. The numerical analysis and FEM analysis are performed to vary attachment of stator side or rotor side, radial flux magnetization or parallel flux magnetization, magnet arc angle in the condition of constant air gap. This results have more reliable data comparing with test result of the back EMF for 7 phase BLDC motor.
An Experimental Study on the Implementation and Stabilization of Atmospheric Pressure Glow Discharge
Choi, Sang-Won ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 42~46
Ionizers are essential in various areas of manufacturing industries to protect electrostatic hazards and to reduce inferior products. For ion sources used in the charge neutralizers, there are corona discharge, soft X-ray, ultraviolet and glow discharge. Glow discharge has lots of attractive properties, such as lower discharge sustaining voltage, no generation of ozone, and so on. In this paper, we did an experimental study to trace the mechanism and stabilization of atmospheric pressure glow discharge using the several size and shape of electrodes. As an experimental result, to sustain conditions of atmospheric pressure glow discharge is that discharge voltage is 360V, discharge current is 12mA, apply frequency is 1kHz between electrodes when positive electrode is molybdenum(Mo) and negative electrode is copper(Cu). We confirmed that the mechanism and stabilization of atmospheric glow discharge is deeply concerned with the shape and material of electrode for discharge. Especially, glow discharge in atmospheric pressure was well generated and sustained according with the physical properties used electrode materials, example melting point, thermal conductivity, and etc.
Analysis of Thermal Characteristics for the Fire Risk Assessment According to Partial Disconnection on the VCTF and IV Electric Wire
Kim, Doo-Hyun ; Kim, Sung-Chul ; Lee, Jong-Ho ; Park, Jong-Young ; Park, Young-Ho ; Lee, Hyung-Jun ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 47~52
Many researches on fire risk for normal electric wiring have been pursued in advanced countries such as the USA and Japan, but comparative studies of the partial disconnection and normal state of electric wires have not been conducted. Detection system for the cause of partial disconnection is not developed and prevention countermeasure for electrical fire by the cause is not effective. Therefore, in this paper, partial disconnection characteristics on electric wires were derived and analyzed by experiment and electrical-thermal finite element method(Flux 3D) on the model wires which consist of VCTF(PVC insulated PVC sheathed Cap Tyre Flexible Cord, KS C 3304) and IV(lndoorwire PVC, KS C 3302). VCTF is used in wiring portable electric appliances and the IV is used indoors. Interrelationships between partial disconnection premonitory symptom and current were derived and analyzed by the characteristics based on experiments and thermal analysis for electric wire according to current under normal state and 200% overload state of rated current.
Assessing the Safety Performance of Small-sized Contractors and Improvement Measures
Choi, Seung-Mo ; Lee, Dong-Eon ; Son, Chang-Baek ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 53~58
This paper presents the findings obtained from the investigation of fatal disasters occurred by small-sized construction firms which have been accepted as to provide lower safety performance other than large-sized construction enterprises and cause more than half of the safety accidents in average. The study identifies the current status of safety performance provided by the small-sized construction contractors in details, find the issues involved with lack of safety performance, and suggest the improvement measures derived from the findings. A survey questionnaire was administered to the construction contractors, which are listed in the database of Construction Association of Korea as to fall into rank between 501st and 1000th in construction capacity. Safety issues such as the performance of safety management system, safety control structure, safety cost relative to safety control, education devoted to safety improvement, usage of safety garments or individual protective tools, and activities to maintain safety performance on site, etc were investigated from the study.
Prediction Model of Chloride Penetration in Concrete Bridge Deck Considering Environmental Effects
Kim, Eui-Sung ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 59~66
Recently, the deterioration of reinforced concrete structures, primarily due to corrosion of steel reinforcement, has become a major concern. Chloride-induced deterioration is the most important deterioration phenomenon in reinforced concrete structures in harsh environments. For the realistic prediction of chloride penetration into concrete, a mathematical model was developed in which the effects of diffusion, chloride binding and convection due to water movement can be taken into account. The aim of this research was to reach a better understanding on the physical mechanisms underlying the deterioration process of reinforced concrete associated with chloride-induced corrosion and to propose a reliable method for estimating these effects. Chloride concentrations coming from de-icing salts are significantly influenced by the exposure conditions such as salt usage, ambient temperature and repeated wet-dry cycles.
A Study on the Strength Comparison of Steel Pipe Support using the Structural Analysis Program
Paik, Shin-Won ; Park, Jong-Keun ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 67~71
Formwork is a temporary structure that supports its weight and that of fresh concrete as well as construction live loads. Slab formwork consists of sheathing, stringer, hanger and shore. In construction site, pipe supports are usually used as shores which are consisted of the slab formwork. In this study, compressive strength of 80 pipe supports was measured by knife edge test and plate test. Buckling load of pipe supports was analyzed by structural analysis program(MlDAS). Theoretical buckling load with/without initial deformation was got by theoretical analysis. According to these results, buckling load which was analyzed by structural analysis program(MlDAS) was larger than compressive strength of knife edge test and plate test. Theoretical buckling load without initial deformation was larger than compressive strength of knife edge test and plate test. But Theoretical buckling load with initial deformation was lower than compressive strength of knife edge test and plate test. Initial deformation equation for test method according to the pipe support length was suggested. Therefore, the present study results will be used to design the slab formwork safely.
Safety Management Information System in Construction Work;Focus on Tunnel Work
Park, Jong-Keun ; paik, Shin-Won ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 72~78
In any form of construction work, it is essential that accidents be prevented at every stage from foundation preparation to build completion. For this, it is necessary to use models that can assess risk and provide instruction for safe work processes so that the risk of accidents is reduced. Currently, however, very few models can perform these tasks. In this paper, we presents a model that assesses risk quantitatively by analyzing risk factors involved in stage of construction such as foundation work, erection work, structural work, equipment work, finishing work and etc work. The model performs assessment based on examples of accidents and by investing actual conditions during construction. In addition, we presents in this paper a safety management system was developed to assess risk during construction and to effectively train laborers.
The Effects of Reinforcing in Concrete Crack by AIG Method
Oh, Se-Wook ; Youn, Il-Ro ; Cho, Hong-Dong ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 79~84
Auto injector grouting method as low pressure injected by using epoxy and Boyle's law is very excellent method in economical efficiency and construction work because injected process can be dealt with collectively. For estimation of filling capacity purpose of this study compared the Auto injector method with the piston injector method. In this study, the tests allow for width of crack, injected angle of epoxy resin and injected method were performed using concrete block specimen making artificial crack. The results of test, tilling et1iciency of epoxy by Auto Injector grouting method verify to better than the piston injector method and uniaxial strength increased about 11% than standard specimen.
The Evaluation of Work Ability and Job Stress for Subway Worker
Kim, Yu-Chang ; Kim, Jong-Gone ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 85~89
Work ability and job stress have become the important issues in Korean workplace recently. This study researched work ability and job stress and also analyzed correlation with work ability and job stress using the Work Ability Index and the Karasek's Job Content Questionnaire against 742 subway workers. As the results, Work ability in subway workers was good in general. The relation between job stress and job type showed statistical significance (p<0.05). The relation between job stress and diseases showed statistical significance in musculoskeletal disorders(p<0.05), heart disease, and gastrointestinal disease. The correlations between work ability and job stress showed statistical significance in job demand and social support(p<0.05). The result of this study could be useful to manage the work ability of aging worker and the job stress in industry.
An Analysis of the Vulnerable-Pedestrian Crossing Time in Test Crosswalk
Kim, Tae-Ho ; Hu, Uk ; Hwang, Eu-Pyo ; Won, Jai-Mu ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 90~98
Presently, pedestrian's signal time models in korea are not considering Vulnerable-Pedestrian. So, the safety of Vulnerable-Pedestrian is being threatener and the number of accidents is increasing. Besides, the existing operational system for pedestrians can't offer the cross signal time in road corresponded the changing environment when the school zone is revitalized and the Silver zone is introduced for Vulnerable-Pedestrian. Conclusively, Vulnerable-Pedestrian's signal time models which are able to consider classified Vulnerable-Pedestrian speed, Vulnerable-Pedestrian perception-reaction time, Vulnerable-Pedestrian Spare(congestion-delay) time are suggested by the result of experiment in virtual crosswalk. the application of suggested models in this study to the site. It is possible to use as a basic stuff on study of pedestrian's signal time and expected to contribute the safety and mobility in future.
Flame Retardancy and Electrical/Mechanical Properties of LDPF/EVA Blend
Ryu, Boo-Hyung ; Lee, Chung ; Kim, Ki-Yup ;
Journal of the Korean Society of Safety , volume 23, issue 4, 2008, Pages 99~104
In this research, magnesium hydroxide as a flame retardant agents and zinc borate as a synergist were mixed with LDPF/EVA blended samples, in order to improve their flame retardancy. We attempted to select the best mixing ratio of the LDPF/EVA blend and the optimum amount of magnesium hydroxide and zinc borate by the comparison and analysis of the flame retardancy, the electrical properties such as the volume resistivity and dielectric loss tangent, and the mechanical properties such as the tensile strength and elongation at break. Particularly, specimen which is the 6phr of zinc borate and 10phr of magnesium hydroxide 70/30phr adding to the LDPF/EVA blended samples has been most excellent in flame retardancy and electrical/mechanical properties.