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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
A Study on the Development of Performance Based Fire Risk Assesment Program
Rie, Dong-Ho ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 1~6
`SOS', Simulator Of Safety assessment for fire, was developed to simulate fire safety assessment for a structure which is geometrically complex. The program(SOS) is intended to use for searching as well as designing tools to analyse the evacuation safety through a wide range of structure conditions. The computer program has a function which importing FDS's calculating results to each individual resident in the structure. These attributes include a walking speed reduction by producing visibility reduction for each person on the fire.
pathfinding algorithm is adopted to calculate the simulation of escape movement, overtaking, route deviation, and adjustments individual speeds in accordance with the proximity of crowd members. This SOS program contributes to a computer package that evaluates the fire safety assessment of individual occupants as they walk towards, and through the exits especially for building, underground spaces like a subway or tunnel.
A Study on the Temperature Distribution at the Surface of Diesel Particulate Filter and Partitioned Electric Heater according to the Conditions of Heating and Flow using an Infrared Temperature Camera
Lee, Choong-Hoon ; Paik, Sung-Chon ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 7~14
The temperature distribution in a surface of diesel particulate filter(DPF) was measured using an infrared temperature camera. In order to regenerate the DPF, five partitioned electric heaters were used for heating the ceramic filter. The five partitioned heaters were switched on/off with some time interval one the other. The surface temperature distribution in the ceramic filter and electric heaters were measured with varying both the electrical power supply to the heaters and the mass flow rate of the air supply from a blower. The higher mass flow rate in the DPF system enhanced the uniformity in the surface temperature distribution of the ceramic filter due to effective convection heat transfer. The flow in the monolith ceramic structure of the DPF move mainly in the axial direction, which could be identified from the surface temperature of the ceramic filter.
A Forensic Engineering Study on Bursting Accident of Composite Pressure Vessel in CNG Bus
Kim, Eui-Soo ; Kim, Jin-Pyo ; Park, Nam-Kyu ; Kim, Youn-Hoi ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 15~21
The bus using compressed natural gas(CNG) trend to be extended in use internationally as optimal counter-plan for reducing discharge gas of light oil due to high concern about environment. But, Composit pressure vessels(CPV) to be equipped with CNG bus is always involved in the point that safety accidents happen due to having compressed natural gas. In this report, we analysis the cause of CPV bursting accident by reviewing design and manufacture factor and suggest preventive measure through this case.
Patch Reinforcement and Safety Evaluation for Pressure Vessel with Internal Wall Thinning
Song, Tae-Kwang ; Chun, Yun-Jae ; Myung, Man-Sik ; Kim, Yon-Jae ; Lee, Tae-Hee ; Park, Ji-Yoon ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 22~29
This paper provides the evaluation method for the pressure vessel with internal wall-thinning defect, which is based on ASME design criteria. Pressure vessel has wall-thinning partially and patch reinforcement has been attached for reliable operating. However, present partial wall thinning could be through wall thinning at the next inspection time with present corrosion progress speed. Therefore safety margin was calculated for various conditions from present wall-thinning condition to additive patch reinforced condition via two-dimensional and three-dimensional, geometrically linear FE analyses using elastic materials.
Measurement of Tensile Properties Dependent on the Small-Scaled Specimen Dimension for Evaluation of In-Service Materials Properties
Huh, Yong-Hak ; Kim, Dong-Iei ; Kim, Dong-Jin ; Lee, Hae-Moo ; Park, Jong-Seo ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 30~34
To evaluate the mechanical properties of in-service materials, tensile properties measurement using small-scaled specimen has been carried out. Tensile testing specimens with various dimensions, including standard and sub-size specimen specified in ASTM and ISO and small-scaled specimen, were prepared. Tensile strain in small-scaled specimen was measured using micro-ESPI system set up in this study. This system was used in the specimen with the parallel length of 2 mm and in subsequently measuring the strain under tensile loading. From each type of tensile specimen, stress-strain curves were determined. The dimension effect of the tensile properties was investigated comparing the tensile results obtained from standard specimens and small-scaled specimens. It was shown that the tensile strength for the small-scaled specimen is lower by 15% than those for the standard specimen.
The Design of an RFID/USN Event Monitoring System for N ext Generation Gas Safety Management
Lee, Chan-Gun ; Park, Jae-Hwa ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 35~42
There are many efforts toward the development of next generation gas safety management systems to improve the assurance, availability, and efficiency of the extant systems. Among them, the application of ubiquitous technology, such as RFID and USN, to the system is regarded as a promising approach for enabling such an innovation. Recently the ubiquitous technology became much affordable and available than before thanks to the reduced production cost and wide proliferation of the ubiquitous devices. In this paper, we analyze the core requirements for the next generation gas safety management systems based on the ubiquitous technology, and present an architectural design of a middleware to facilitate the realization of the system. We formally define an event model and present how to specify various situations related to gas safety management using the proposed event model.
Development of The Magnetic Abrasive Using Ba-Ferrite and GC, CBN
Kim, Hee-Nam ; Yun, Yeo-Kwon ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 43~48
The magnetic polishing is the useful method to finish some machinery fabrications by using magnetic power. This method is one of the precision polishing techniques and has an aim for clean technology in the transportation of the pure gas in the clean pipes. The magnetic abrasive polishing method is not so common in the field of machine that it is not known to widely. There are only few researchers in this field because of non-effectiveness of magnetic abrasive. Therefore, in this paper deals with development of the magnetic abrasive using Ba-Ferrite. In this development, abrasive grain GC and CBN has been made by using the resin bond fabricated at low temperature. And magnetic abrasive powder was fabricated from the Ba-Ferrite which was crushed into 200 mesh. The XRD analysis result shows that only GC, CBN and Ba-Ferrite crystal peaks were detected, explaining that resin bond was not any more to contribute chemical reaction. From SEM analysis, we found that GC, CBN abrasive and Ba-Ferrite were strongly bonding with each other.
Ionizing Characteristic of Glow Discharge by Controlled Air Flow Rate
Choi, Sang-Won ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 49~53
Glow discharge has lots of attractive properties, such as lower discharge sustaining voltage, no generation of ozone, and so on. And more, ionizer was developed recently using an atmospheric pressure glow discharge. On the other hand, ionizer needs a compressed or blown air to transport ion for charged objects. This air is very useful in explosive hazardous area to prevent the explosion of flammable gas and/or vapor by ignition sources, e.g. electrical spark. In this paper, we investigated the ionizing characteristic of atmospheric pressure glow discharge by controlled air flow rate from 5 liters to 60 liters a minute, and compared with decay time between the corona discharge and glow discharge as a function of some direction and distance from discharge ion source. We confirmed that an air flow rate needs 25 liters a minute to sustain the most suitable atmospheric pressure glow discharge and to increase an ionizing efficiency.
Reduction and Decomposition of Hazardous NOx by Discharge Plasma with
Park, Sung-Gug ; Woo, In-Sung ; Hwang, Myung-Whan ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 54~60
The objective of this study is to obtain the optimal process condition and the maximum decomposition efficiency by measuring the decomposition efficiency, electricity consumption, and voltage in accordance with the change of the process variables such as the frequency, maintaining time period, concentration, electrode material, thickness of the electrode, the number of windings of the electrode, and added materials etc. of the harmful atmospheric contamination gases such as NO,
etc. with the plasma which is generated by the discharging of the specially designed and manufactured
catalysis reactor and SPCP reactor. The decomposition efficiency of the NO, the standard samples, is obtained with the plasma which is being generated by the discharge of the combination effect of the
catalysis reactor and SPCP reactor with the variation of those process variables such as the frequency of the high voltage generator(
), maintaining time of the harmful gases(
), initial concentration(
), the material of the electrode(W, Cu, Al), the thickness of the electrode(1, 2, 3mm), the number of the windings of the electrode(7, 9, 11turns), basic gases(
, air), and the simulated gas(
) and the resulting substances are analyzed by utilizing FT-IR & GC.
Crack Opening Area Assessment of Circumferential Though Wall Crack in a Pipe Subjected to Tension and Bending
Kim, Sang-Cheol ; Kim, Maan-Won ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 61~66
It is important to calculate the exact crack opening area in the cracked pipe subjected to axial force and bending moment. Among many solutions for obtaining the crack opening displacement, Paris-Tada's expression, which is derived from energy method, is open used in fracture analysis for piping crack problems because of its simplicity. But Paris-Tada's equation has conservativeness when radius over thickness ratio(R/t) is ten or less, for it is based on the stress intensity factor solution having a compliance function derived from a simple shell theory. In this paper we derived a new expression using a different stress intensity factor solution which is able to consider the variation of compliance through wall thickness in a cracked pipe. Conservativeness of both equations was examined and compared to finite element analysis results. Conservativeness of the new equation is decreased when R/t > 10 and increased slightly when R/t < 10 compared with Paris-Tada's. But Both equations were highly conservative when R/t < 10 compared with finite element analysis results.
The Measurement and Calculation of the Lower Flash Points using of Binary Systems Using Cleveland Open Cup Tester
Lee, Sung-Jin ; Ha, Dong-Myeong ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 67~72
The lower flash points for the flammable binary systems, 2-propanol+formic acid and 2-propanol+n-butyric acid, were measured by Cleveland open cup tester. The optimization method using van Laar equation and the Raoult's law were used to estimate the lower flash points and were compared with experimentally-derived data. The calculated values based on the optimization method were found to be better than those based on the Raoult's law.
A Study on the Fire Hazards of Puzzle Mats in Group Day Care Home
Park, Hyung-Ju ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 73~78
The fire hazards and combustion heat of puzzle mats in group day care home were analysed using variable external irradiation level. The fire hazards such as ignition time, ignition temperature, mass loss rate, and flame temperature profile were measured. Incident heat fluxes of
were selected for these experiments. All samples were tested in the horizontal orientation and were wrapped in a single layer of aluminium foil. Each sample was nominally 20mm thick and 100mm square. Five samples of puzzle mat were tested in the study : Type A, B, C, D and E. Type A, B and C are all general grades whereas Type D and E are both Flame retardant grades. As results, Type E of FR-grade showed the best characteristics in safety of the early fire from ignition time, critical heat flux, and ignition and flame temperature data of this study. All specimen of G-grade(Type A, B and C), however, showed the weak in safety of fire.
An Improvement of Welding Method for the Corrugated Stainless Steel Tubing(CSST)
Kim, Wan-Jin ; Yi, Yeong-Seop ; Choi, Jin-Lim ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 79~83
The corrugated stainless steel tubing(CSST) for the fuel gas piping system can be installed easily and quickly. It is often constructed under the ceiling and the wall which has a good flexibility and installation in comparison with iron pipe. However, the quality of the CSST is determined to depend upon the welding skill of stainless steel tubing. In this study, it is tested by controlling jet point of Ar as inert and cooling gas, and also compared with the bead state of welding point and the performance. As a result, it has the best condition when the jet point of Ar is located behind
of the welding point.
Risk Evaluation of Longitudinal Cracking in Concrete Deck of Box Girder Bridge
Kim, Eui-Sung ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 84~90
The occurrence of longitudinal cracking in concrete deck of box girder bridge is affected by many factors, but the most important factors are the shrinkage and thermal gradient of deck slabs. In this study, therefore, the tensile stresses at the bottom of deck were calculated from the experimental data(autogeneous shrinkage, drying shrinkage, and thermal gradient of deck slab). Also, the possibility of longitudinal cracks at bottom of deck was estimated. For this purpose, full-scale box girder segments have been fabricated and tested. The thermal gradients and shrinkage strains of deck slabs were measured after placement of concrete. Also, analytic program was conducted for the evaluation of longitudinal cracking in bridge deck considering differential shrinkage induced from non-uniform moisture distributions in concrete.
Hydraulic Behavior Affecting the Safety of Reflected Breakwater
Kim, Sung-Duk ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 91~96
A reflected breakwater can be affected by wave pressure and power because it is to be concentrated by wave energy. The present study is to estimate hydraulic behavior affecting around a reflected breakwater, which is discontinuity cases and various angle of coner at the breakwater. The numerical model to investigate wave diffraction, which is important hydraulic factor in the ocean, is performed by using direct boundary element method. The present numerical results are compared with the solutions of approximate and absolute based on an eigenfunction, and the solution of analytical by Fresnel integral. The results of the present numerical simulation agreed well with those of the published numerical and analytical data. As a result of this study, wave height is high at the comer of breakwater, and it is to be high if angle of conner at the reflected breakwater is small.
A Study on the Evaluation of Durability of Fiber Reinforced Concrete According to the Change of External Conditions
Kim, Nam-Wook ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 97~104
This study was intended to evaluate the permeable performance through a change of reinforcing materials, curing condition, durability evaluation and permeability test, and to select the reinforcing material which could reduce the durability and water tightness from it, as the study for considering how the change of the outside's environment factors that the concrete structure actually contacted with impacted the concrete's durability especially the permeability by referring to such the background of the study. Accordingly, it was judged that evaluating the permeability by considering the severe environment condition where the concrete structure was placed in was more reasonable than measuring the existing permeability coefficient conducted in the sound state for the permeability evaluation of actually-used concrete structure. In this study, it also could be known that the specimen of hybrid fiber reinforced concrete which mixed the long and short steel fiber was the most effective for water tightness enhancement in severe environmental conditions.
The Study Used Brog's Scale on the Lower Extremity Supporter
Kim, Yu-Chang ; Chang, Eon-June ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 105~110
This study focused on the decreased effect of the work load on using the lower extremity supporter in kneeling posture. Fatigue measures included subjective discomfort ratings through the use of the Borg's CR-10 scale based parameters. The resting period and work method were considered as independent variables. The break time conditions are grouped into 10 seconds after work for 1 min and not exist break time. The method of work conditions are divided into four types. There are kneeling with the lower extremity supporter, kneeling with the knee protector, just kneeling and squatting. The result of the ANOVA of the shift value of subjective discomfort showed the followings: 1) There were differences as regards to the method of the work, the break time and the part of body(
). 2) The lower extremity supporter showed the least subjective discomfort in other part of body except the upper leg.
Perceptional Characteristics of Effective Safety Signs Corresponding to International Criteria
Lim, Hyeon-Kyo ; Park, Young-Won ; Jung, Gwang-Tae ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 111~118
In usual safety signs are final means to transmit hazard information so that the importance of them cannot be emphasized too much. Nevertheless, in Korea, few people are interested in functions of safety signs so that evaluation of safety signs are seldom committed. This research was conducted to evaluate and compare perceptional characteristics of safety signs, especially "Fall" signs, by Semantic Differential Method and Multi-dimensional Scaling Method, with undergraduate students as well as industrial workers. According to research results on several signs evaluated high through suggested procedure, action inducibility was different for students majoring in different sciences, but it had common elements in the sense of 'openness' or 'arrangements'. Besides, perceptional images on safety signs were mainly recognized with bases of 'arrangement' for student group and 'simplicity' for industrial workers, respectively, and their maps corresponded well with each other by partial rotating so that students and workers seemed to recognize safety signs with similar factors though their name might be different. However, since perceptional characteristics including image map, comprehensibility, and action inducibility were similar for student group whereas those were not for worker group, it was concluded that the test for action inducibility would be absolutely necessary for safety signs for workers' group.
Comparison of Different Work/Rest Schedules of a Repetitive Upper-limb Task Based on Perceived Discomfort and Heart Rate
Lee, In-Seok ; Haslam, Roger ; Song, Young-W. ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 119~124
Many automobile assembly workers often do several cycles of tasks continuously, i.e., without breaks, to get a longer break. This is not recommended since the dose of fatigue increases exponetially with time and it takes much longer time to recover. In this study, a laboratory experiment was conducted to investigate the effect of work/rest schedules on workload of a repetitive upper-limb task. Eleven male subjects participated in the experiment, in which simulated screw driving tasks were carried out repetitively with 3 different work/rest schedules: standard breaks(1 cycle of work at a time, 60 20-s breaks), medium breaks(5 cycles of work at a time, 12 100-s breaks), and long breaks(10 cycles of work at a time, 6 200-s breaks). The result showed that medium- and long-breaks schedules significantly increased the level of perceived discomfort and %HRR as compared to the standard-break schedule. The subjects' preference was not statistically different among work/rest schedules, which might be caused from the absolutely low level of workload of the experimental tasks. From the results, it is recommended to have frequent and shorter breaks rather than infrequent and longer breaks to decrease the level of physical workload. A more expanded studies, however, should be carried out to provide more practical safety guidelines on the work practice of continuous working without breaks among automobile assembly workers.
Optimal Design of the PSC Beam Reinforcement for Minimum Life-Cycle Cost
Bang, Myung-Seok ; Han, Sung-Ho ;
Journal of the Korean Society of Safety , volume 23, issue 5, 2008, Pages 125~130
To optimize the selected reinforcing method for application to PSC Beam bridges, the reliability analysis was performed with consideration for the increase and decrease of the member section based on the standard design section, and the minimum life-cycle cost(LCC) was calculated from this analysis with consideration for the aleatory uncertainty. Moreover, the mean, 50%, 75%, and 90% distributions of the analysis results were re-evaluated quantitatively by considering the effect of the epistemic uncertainty. The reliability results gained from the application of the reinforcing method, as well as the optimal design method based on the minimum LCC, will provide more reasonable design criteria for the PSC Beam bridges.