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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 8, Issue 4 - Dec 1993
Volume 8, Issue 3 - Sep 1993
Volume 8, Issue 2 - Jun 1993
Volume 8, Issue 1 - Mar 1993
Selecting the target year
A Study on the Effects of EGR ratio on Engine Performance and Emission in a 4 Cylinder 4 Cycle Gasoline Engine
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 3~15
A multi-cylinder four cycle spark ignition engine equipped with on exhaust gas recirculation(EGR) system to reduce nitric oxide emission and to improve fuel consumption rate has been comprehensively simulated In a computer program including intake and exhaust manifolds. To achieve these goals, this program was tested against experiments performed on a standard production four cylinder four cycle gasoline engine with EGR system. As EGR rate Increased, the maximum temperature of combustion chamber and NO omission concentration decreased under each driving condition. But the emission concentration of CO didn't change much through whole district in spite of the increase of EGR rate. Fuel consumption rate improved under each driving condition according to the increased of EGR rate until 10 percent EGR rate. Therefore the degree of EGR depend not only on the NO emission but also on the economy and the engine performance criteria of the engine.
Deformation of the Tubes in Copper/Brass Radiator with Rise of Temperature and Pressure
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 16~20
The combined effect of increased pressure/temperature and the reduced material thicknesses act to increase the stress on the radiator componets. The design life of the radiator is influenced by the cyclic stresses and corrosion, which act to weaken the materials, radiator mechanical failure occurs when a tube or solder Joint ruptures, causing coolant loss or insufficient heat rejection. Therefore, in this study, through strain measurement of the tubes in copper/brass radiator, the strain distribution of the tubes in radiator as function of temperature and pressure is obtained.
Optimal Design of Golf Club by Considering Twisting Moment of Grip
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 21~26
This paper presents a method of stress analysis of golf club. We define the sweet spot of golf club by the magnitude of torsional moment. Transfer matrix method was used for optimal design on sweet spot of golf club.
A Study on the Creep Fracture Life of Al 7075 alloy( I )
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 27~40
High temperature tensile tests, steady state creep tests, Internal stress tests and creep rupture tests using A17075 alloy(
) were performed over the temperature range of 9
) and stress range of 0.64~17.2(kgf/
). The main results obtained in this paper were as follows. (1) The activation energies for yielding at the temperature of 0.4
were calculated to be 25.7~36.5kcal/mol, which were nearly equal to the activation energies for creep. (2) At around the temperature of 9
and under the stress level of 10~17.2(kgf/
), and at around the temperature of 200~41
and under the stress level of 1.53~9.55(kgf/
) and again at around the temperature of 470~50
and under the stress level of 0.62~l.02(kgf/
), the applied stress dependence of steady state creep rate
measured were, respectively, 3.15, 6.62 and 1.1, which were in good agreement the calculated stress dependence
obtained by the difference of the applied stress dependence of the Internal stress and the ratio of the internal stress to the applied stress. (3) At the temperature range of 0.4~0.43
, and at the temperature range of 0.52~0.75
and again at the temperature range of 0.82~0.85
, the activation energies
obtained by steady state creep rate, respective, 26. 16, 34.9, 36.2 and 36.1kcal/mol, which were in good agreement with those obtained with the activation energies under constant effective stress and the temperature dependence of Internal stress. (4) At the temperature range of the 0.52~0.73
and under the stress level of 1.53~9.55(kgf/
), the stress dependence of rupture life(n’) measured was 6.3~6.6, which was in good agreement with the stress dependence of steady state creep rate(n). And at the same condition the activation energy for rupture(
) measured was 32.0~36.9kca1/mol, which was also in good agreement with the activation energy obtained by steady state creep rate (
). (5) The rupture life(
) might be represented by athermal process attributed to the difference of the applied stress dependence of the internal stress and the ratio of the internal stress to the applied stress, and the thermal activated process attributied to the temperature dependence of the internal stress as
/dT) - (
/dT)｝/RT]. (6) The relationship betwween Larson-Miller rupture parameter and logarithmic stress was linearly decreased, so creep rupture life of Al 7075 alloy seemed to be predicted exactly with Larson-Miller parameter.meter.
A Study on the Effect and Formation of Shear Lip for Al 2024-T3 Materials
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 41~46
This Paper aims to examine the effect of shear lip formation from cross-sections on fatigue crack propagation rate in order to study the fatigue fracture behavior of the high strength aluminum material (Al 2024-T3). The following tests were achieved from this research. 1. As a result of depressing shear lip artificially by adding a side groove to a specimen, it is shown that the propagation rate of fatigue crack is faster than that of general specimen. 2. Through the two-step load test, the phenomenon that the shear lip decreases In the part of changed load gets observed. Consequently It Is shown that the crack propagation rate gets faster.
Prediction d Fatigue Growth Behavior of Short Cracks
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 47~53
The growth of short cracks can be well described in terms of the effective stress intensity factor range, which is calculated on the base of crack closure. The relation between the crack opening SIF and crack length is determined from the experimental results. The crack opening SIF of short cracks, Kop, can be predicted from the crack opening SIF at threshold of long crack, Kop.L. The growth rate of short cracks at notch root can be predicted from the crack opening SIF of short cracks, Kop, and the growth equation of long cracks in region II.
CAD/CAM System Development for Automatic Creation and Manufacturing of Three Dimension Objects
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 54~60
The purpose of this study is to develop a CAD/CAM system for automatic creation and manufacturing of three dimension objects. The computer system used in this study made RAM 2M, CPU 80386, VGA graphic card. The results in this paper are as follows ; 1. By interconnect PC(personal computer) and NC(numerical control) milling machine with RS232C connector, we was constructed with CAD/CAM system. 2. The developed algorithm in this study is able to be design of three dimension object on the computer CRT and manufacturing of NC milling machine. 3. Because of design and modifying on the PC of objects, we can be saving time, cost and improvable precision of objects. 4. Essentially, we expect industrial accident to reduse according as we takes advantage of CAD/CAM system.
Computer-Assisted System for Accident Analysis and Mul-function Protection in Industrial Robot
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 61~64
Until now, Industrial robotic sa(ety problems are not considered as a indust rial safety problems. In order to reduce industrial robotic safety problem, analyzing problem, risk control, and developing industrial robotic standard s are necessary. In this study, SAFEMIR(Safety Management for Industrial Robotic) is developed for preventing mul-function in industrial robotics. This system is consisted of Da ta Base Management System Module and Expert System Module which Is a part of Articial In telligence. Borland C++ and Foxpro 2.0 are used for implementing this system.
A Study on the Safety Work for an Injury of Operation Hazards( I ) (Press, Cran, Air Compressor)
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 65~72
This study is conducted for both examination of a possiblity of danger and investigation of operational condition of selected 120 companies, to establish the safety standard of workplace hazards.
A Study d the Optimazation the Cutting Condition Selecting System for the Rationality of Mould Manufacture
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 73~81
In recent years, mould industry in machining requires to increase machining productivity and to reduce costs, To adapt this trend it is necessary to optimize machine condition, Even though many researches in this area introduced various way to set the optimal condition, still there are not enough. Therefore this research was done to select the optimal cutting condition for industry, and to develop the computer program to select the optimal cutting condition automatically. The result of this research will contribute to increase machining productivity of various mould companies with the automatic selection of optimal cutting condition.
A Study on the Determination d Membership Function for Manual Materials Lifting
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 82~90
Manual lifting, as a part of Manual Materials Handling Activities, is recognized by authorities in the field of occupational health and safety as a major hazard to industrial workers. The most important problem in applying fuzzy model of manual materials lifting is the decision of membership functions on each approaches. : Biomechanical, Physiological, Psychophysical. The primary objectives of this paper suggests to process deciding the most acceptable membership functions for establishing permissible weights on manual lifting activities using fuzzy sets.
The Development of Fuzzy to Decide System Failure Rate
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 91~94
The main purpose of this study was to develop fuzzy models in order to decide system failure rate in industrial accident prevention. The purposed linguistic approach uses the Zadeh's concept of a linguistic variable with value which are not number. The problem of measurement Is the assignment of numbers to reprresnt properties of the involved events, object, or situation. Thus, in this study, part standard compatibility function was used.
Design of Snubber for PWM Inverter
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 95~100
In power transistor switching circuit have shunt snubber(dv/dt limiting capacitor) and series snubber (di/dt limiting inductor). The shunt snubber is used to reduce the turn-off switching loss and the series snubber is used to reduce the turn-on switching loss. Design procedures are derived for selecting the capacitance, inductor and resistance to limit the peak voltage and current values. The action of snubber is analyzed and applied to the design for safety PWM inverter.
A Study on the Electrification Phenomena Affecting Industrial Disaster
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 101~106
The streaming current of insulating oil increases with increasing oil velocity and oil amount, A contact potential difference as an energetic state exits in the polymer thin film, both sides of which are contacted by two different metals having different work functions. Accordingly, the potential difference may be a cause for the short circuited transient current flowing through the external circuit. The polymers are electrificated as the electric field Is supplied, and the currents flow with increasing temperature.
A Study on the Explosion to Fire Transition Phenomena of Liquidfied Petroleum Gas
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 107~113
Small rectangular explosion chamber of its size 25cmX25cmX32cm with a circular bursting diaphram at the top was used to study the mechanism of gas explosion to fire transition phenomena, the process of ignition of solid combustibles during a gas explosion. To visulize the explosion to fire transition phenomena, transparent acryl window and high speed camera system were used. The test piece of solid combustible in this experiments was a 5cm
5cm square sheet of newspaper which was placed in the explosion chamber filled with a LPG-air mixture. The mixture was ignited by an electric spark at the center of the chamber. Explosion to fire transition phenomena and the behavior of out flow and in flow of gas through the opening yielded by bursting the diaphram was visualized with shlieren system and without shlieren system. Diameter of a bursting dlaphram at the top of the explosion chamber was varied 5cm, 10cm, and 15cm, and the position of test piece were varied with 6 point. Explosion pressure was measured with strain type pressure transducer, and the weight difference of the test piece before and after each experimental run was measured. By comparing the weight difference of solid combustibles before and after the experiment and the behavior of out flow and inflow of gas after explosion, it was found that the possibility of ignition was depends on the LPG-air mixture concentration and the exposure period of test piece to the burnt gas. Test result of this experiments it was found that the main factor of this phenomena are that heat transfer to the test piece, and the pyrolysis reaction of test piece. Based on the results, the mechanism of the explosion to fire transition phenomena were inferred ; gas explosion- heat transfer to solid combustibiles ; pyrolysis reaction of solid combutibles : air inflow ; mixing of the pyroly gas with air ignition.
Explosion Characteristics of Nonhomogeneous LPG-Air Mixtures
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 114~119
The explosion characteristics of nonhomogeneous LPG-Air mixtures was measured in a cylindrical vessel and a pipe. The maximum explosion pressure, the maximum rate of explosion pressure rise, and the flame propagation velocity were measured and compared with that of homogeneous explosion by changing the effective factors on the explosion of nonhomogeneous mixtures such as pressure difference, effusion time and delay time. Explosion was occured even in the lower concentration than the lean flammability limit of mixture. The maximum explosion pressure was increased with increase of LPG concentration, however, the maximum explosion pressure rise was not in the nonhomogeneous explosion. An d the flame propagation velocity was decreased with nonhomogeneity, however, the maximum explosion pressure was always above 0.7kg/
Effects of Screen Packing Materials an Gas Discharge Dust Containing
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 120~126
This work was carried out to investigate the effects of solid mass flow rate, mean particle diameter and mesh number of screen packing material on minimum carrying velocity, which defined as the superficial gas velocity of the upper limit of chocking phenomenon. Vertical pneumatic conveying was studied on a 4.6cm 1. D. pipe, 180cm in length. Experiments were performed in both the empty and the screen-packed pipe. It was also examined the effect of superficial gas velocity, solid mass flow, mean particle diameter, and mesh number of packing material on pressure drop. Minimum carrying velocity in screen packed-pipe was lower than that in an empty pipe. besides minimum carrying velocity was decreased with increase in mesh number of screen packing material. The pressure drop In vortical packed-pipe was Increased with superficial gas velocity, mean particle diameter, and mesh number of screen packing material.
Abatement Study of TNT Wastes by Porphyrin-Metal Complexes
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 127~132
Porphyrin-catalyzed reduction of TNT to triaminotoluene was performed in both batch reactions and a continuous process. Packed-bed reactors were used to study porphyrin-catalyzed reduction in a continuous process. A reactor was packed with DEAD(diethylaminoethyl)-substituted glass beads on which
_centered deuteroporpgyrin Ⅸ, -2, 4-disulfonic acid was immobilized, and another containing only DEAE glass beads was used as a control. The porphyrin exhibited catalytic activity in its immobilized state up to 100 hours of operation. Based on the successful abatement of nitrobodies by porphyrin-catalyzed reduction in both batch and continuous process, this process is recommended to be used as a pretreatment for biological treatment or carbon adsorption treatment of TNT wastes.
Dynamic Simulation and Controller Design for the Safe Operation of Boiler Drum
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 133~138
The stable and safe operation of a boiler system is essential for ensuring stability of the chemical processes. A dynamic simulation of a boiler drum was performed to identify the dynamics of the boiler drum. The obtained results represented that the variation of process variables disturb boiler system. So, disturbance rejection with tracking and constraints handing was necessary for stable operation of boiler drum. Among many controller, GPC has been known to show good performance in set point tracking than disturbance. In order to improve disturbance rejection performance measurable disturbance term was Introduced in basic GPC model. The controller which had tracking and disturbance rejection was designed for Improving the stable operation of a boiler system.
A Study on the Highway Snow Melting and Deicing System Using Geothermal Energy
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 139~148
Thermosyphons are simple devices that can passively transport thermal energy over relatively long distance with little temperature degradation. These attributes permit the use of low grade thermal energy for thermal control of structures including the snow melting and deicing to the pavement surface. The thermosyphon system requires no costly energy input and Is completely maintenance free. This paper presents the experimental results of the snow melting system in which thermosyphon was utilized to transfer the geothermal energy to the pavement to obviate slipping traffic accidents due to freezing of pavement in winter.
Causes of Industrial Accidents in Costruction Industry : An Exploratory Study
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 149~164
Safety Assessment of Nuclear Waste Incineration Process by Estimating Radiation Dose of Workers and Residential Individuals
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 165~174
For the safety assessment of the demonstration-scale incineration plant for treating the combustible radioactive wastes, radiation doses of a worker and a residential individual were estimated. The demonstration plant showed a good performance of trial-burn tests using non-radioactive tracers with resulting In high mass reduction of around 40 times and very low emmission of dusts through a stack, which promised a high decontamination factor in an order of 10
. Based on the result s obtained from the trial-burns in the process, the estimation of radiation dose for workers and general publics near the plant was made using dose pathway calculation theories. The parametric values for calculation were selected from design and operational results of the process and from more conservative conditions In reference data. The estimated annual doses for workers and residential indivisuals were 3.07
and 4.35 X 10
Sv/y, respectively, which were high enough to operate the process when comparing with the allowable dose limit in the regulation. The dose calculation models were quite applicable with showing an excellent safety for the process.
Volatilization and Toxicity Control of Heavy Metal Chlorides under Combustion Conditions
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 175~182
Volatilization of toxic heavy metals, especially, metal chlorides at elevated temperatures in oxidation conditions was observed using a thermogravimetric furnace since such metal chlorides used to be a cause for the disease of industrial workers by their toxicity and high volatile extent. Most of tested metal chloride compounds were evaporated or decomposed into gas phase at elevated temperatures ranged from 200~90
, while CrCl
became stable with converting into oxide forms. A kinetic model for evaporation/condensation could predict maximum evaporation flux and the calculated values were compared with real evaporation flux. The ratio of two fluxes could be explained as the fraction of impinging gas molecules to the condensing surface(
) and obtained in the range of 10
for the experimented toxic heavy metal chlorides. This ratio might be used to define the volatile extent or toxicity of such toxic metal compounds. The schemes to avoid volatilization of toxic heavy metals Into the atmosphere were suggested as follows ; 1 ) controlling the compositions of metals and Chlorine produced substances( such as PVC ) in the treated materials using a reverse estimation from regulatory limit and characteristics of a processing facility, 2) Installation of wet type devices such as a scrubber for condensing the metal compounds.
Sex Differences in Physical Growth Model
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 183~188
Anthropometric characteristics and considerations of sex differences are essential for the correct design of ergonomic work spaces. This paper is concerned with longitudinal study on the physical growth in Korean youth. Three hundred eighty-seven subjects were selected from third year students of high schools, and their records on physical examination during the last twelve years were surveyed by longitudinal method. For boys and girls, this study investigated the anthropometric characteristics of physical structure and the shape of physical growth. The result showed that the physical growth spurt of girl occurred earlier than that of boy. Also, by regression analysis, the third-order polynomial function was suitable for the growth curves of stature and weight, and there were significant sex differences in the fitted curves.
Anthropometry of Korean People and Safety Reach Standards
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 189~193
Elimination of dangerous points is the most effective method for safety in mechanical equipments. The next effective method is recognized as isolation and/or safe-guarding of dangerous spots from human beings. With progress of mechanical automation technique such as industrial robots, the need for safe-guard-ins is now being enlarged. It is needless to say that when a machine-guard is designed and installed, a comprechensive understanding of human movement is indispensable. But in this country, there is no scientific for those thems, and no one verifield whether it is valid to apply general guideline such as OSHA's to Korean or not. Further, basic anthropometric items for safety reach standards are neither availble nor included in nation-wide anthropometry project. In this research, human anthropometry data of Korean youngsters are analyzed for safety barrier and safety slit width, and compared with guidelines of other countries-Germany, United Kingdom, Japan, and USA. Though they are standards for safety, since they are based upon their own peoples' data, some of them especially foot reach are not not applicable in this country. It should be notified that careful application of numeric value is very important.
A Study on the Grinding Residual Stress of Al 7075 Alloys( I )
Park, Dae-Bong ; Kim, Nam-Kyung ;
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 194~200
Grinding experiments for Al 7075 alloy were carried out to study the influence of grinding conditions and supply methods of grinding fluid on residual stress and surface roughness and grinding force. The residual stress was measured by an X-ray method. The supply method of grinding fluid with a guide nozzle has large decrease value of the tensile residual stress and of grinding force than a normal nozzle. In sparking out state of the grinding work, it is desirable to decrease the depth of cut and the workpiece feedrate for improving surface roughness and mechanical properties.
Space-Time Finite Element Analysis of Transient Problem
Kim, Chi-Kyung ; Lim, Hong-Bin ;
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 201~206
A space-time finite element method was presented for time dependent problem. The method which treat both the space and time unformly were proposed and numerically tested. The weighted residual process was used to formulate a finite element method in a space-time domain based upon continuous Galerkin method. This method leads to a conditional stabie high-order accurate solver.
Numerical Study on Enhanced Heat Conduction of Phase-Change Thermal Energy Storage Devices in The Presence of Natural Convection
Chung, Hong-Chul ;
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 207~212
Numerical inverstigation of heat transfer in phase-change energy storage devices was performed in order to aid In the design process for a finned Phase-Change Material( PCM). A simplified model based on a quasi-linear, transient, thin fin equation, which predicts the fraction of melted phase-change material, and the shape of liquid-solid interface as a function of time, is used. The model is solved by using Finite Volume Method(FVM), and the numerical results have showed good agreement with experimental data.
Automation of Tower Cranes based on Optimal Control Method
Lee, Jin-Woo ; Kim, Sang-Bong ;
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 213~222
This paper is concerned with automation of tower cranes in view of the robust control of tower crane during take-off, load hoisting, load lowering and landing. The model equation of the tower crane is induced by using Lagrange's equation and it is linearized at equillibrium point. The control is realized by adopting the optimal regulator method. The effectiveness is proved through the experimental results for the oscillation control of cargo rope and the position controls of trolley and boom by the implementation of digital control using 16 bits microcomputer for the designed optimal control law.
Electrification Phenomena of Paticles and Counter-Plan of Static Electricity Troubles
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 223~230
일본의 금속 리사이클링 현황( I ) (Fe, Cu, Pb에 대하여)
Journal of the Korean Society of Safety , volume 8, issue 4, 1993, Pages 231~235