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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 17, Issue 4 - Dec 2002
Volume 17, Issue 3 - Sep 2002
Volume 17, Issue 2 - Jun 2002
Volume 17, Issue 1 - Mar 2002
Selecting the target year
Development of Adjust Plate Progressive Die
Bae, Yong-Hwan ; Ban, Gab-Su ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 1~4
A automatic production system was developed for high productivity and safety. The semi-progressive die was unfavorable for more productivity, safety, material extravagance and incongruent high-speed production. Developed progressive die is suitable for the high production and guarantee triple production by acceptance of three array type for automobile adjust plate. We adopt Pro-
for three dimensional computer aided design suitable for the disassembly and assembly evaluation. The conclusion of this study is as follow. First, press die parts solid modeling system is built by using Pro-
through this research and verified allowable tolerance and possibility of assembly and disassembly of parts. Therefore we can reduce die manufacturing time and cost. Second, We produce 1000 units pet hot coil 1ton by traditional method, but we can acomplish material saving effect about 12% as 120 units in case of new progressive die. Fourth, we acomplished manufacturing cost curtailment effect more than 20% in comparison with traditional method.
A Study on Creep Crack Growth Properties of 308 SS for FFS Evaluation of High Temperature Components
Lee, Kyung-Yong ; Baek, Un-Bong ; Yoon, Kee-Bong ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 5~10
For fitness-for-service evaluation of high temperature plant components with defects, crack growth life must be assessed properly as indicated in the recent draft of API 579 code. Type 308 stainless steel has been widely used as a field weld material in the petrochemical industry. In this study, creep crack data of type 308 stainless steel are collected and re-analyzed using
as a characterizing fracture parameter. A unique da/dt versus
relationship was obtained despite of difference of creep deformation constant of the reviewed materials and specimen geometry of the tested specimens. The obtained results can be employed for crack growth life assessment and fitness-for-service evaluation for the cracks in high temperature components. It is also argued that since the effect of creep properties and other material variability on the creep crack growth behavior would be minor the obtained model may be applied for most of the 308 stainless steels.
Development of Measurement System for Crack Growth Using Image Processing Technology
Ryu, Dae-Hyun ; Nahm, Seung-Hoon ; Kim, Yong-Il ; Kim, Si-Cheon ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 11~18
We proposed a new experimental method which is required to easily observe the growth behavior of fatigue cracks. In the proposed method, the image data of cracks were stored into the computer while the cyclic loading was interrupted. After testing, crack length was determined using an image processing software which was developed by authors. By comparing the data measured by the image processing system with those by the manual measurement with a microscope, the effectiveness of the image processing system was established. If the proposed method is used to monitor and observe the crack growth behavior automatically, the time and efforts for fatigue test could be dramatically reduced.
Development of Web-based Creep Property Database
Huh, Yong-Hak ; Baek, Un-Bong ; Lee, Wan-Kyu ; Park, Whi-Lib ; Jung, In-Hyeon ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 19~24
User-friendly-web-based database system for searching creep property data was developed. This system includes about 38000 creep data for 270 different materials including low carbon steel, stainless steel and alloy steel. Data on creep rupture, creep deformation, creep crack growth and creeping materials can be searched through this system. Retrieved data is displayed in numeric form and also presented in graphical form for visualizing the data. Furthermore, the creep rupture data is designed to be fitted to a regression equation of logarithmic stress using time-temperature parameter(TTP). The degree of the regression equation, orthogonal polynomials, was determined using analysis of variance.
The Improvement of Collection Efficiency of Electrostatic Precipitator
Ahn, Kook-Chan ; Kim, Bong-Hwan ; Lee, Gwang-Seok ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 25~30
This paper demonstrates the effects of dust electrical resistivity on electrostatic precipitability. The effects of gas temperature, velocity and humidity on the collection efficency were considered by used of coal fly ashes from fluidized bed combustion boiler. The experiments for collection efficiency were carried out in the pilot plant. The ashes which have non-spherical geometry and high electrical resistivity were used. Electrical resistivity is an important property for the collection efficiency in the electrostatic precipitators. Fly ash resistivity as a function of temperature up
and water concentration(up to 15%) has been experimentally investigated using the resistivity test equipment consisted of the movable electrode, dust cup, and furnace. As the resistivity of fly ash in the operating temperature(
) of an electrostatic precipitator was measured higher than
cm, flue gas conditioning in the electrostatic precipitator to reduce the resistivity of fly ash is required.
Interlaminar Shear Stresses of Laminated Composite Plates Subjected to Transversely Imp
Ahn, Kook-Chan ; Park, Seung-Bum ; Kim, Bong-Hwan ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 31~37
This paper demonstrates the analyses of the interlaminar shear stress of laminated composite plates subjected to transversely impact. For this purpose, a plate finite element model based on the higher order shear deformation plate theory in conjunction with static contact laws is developed. Test materials were CFRP with cross-ply laminate
stacking sequences and angle-ply laminate
stacking deguences with
dimension. As a result, stacking seguence and fiber orientation were found to have a significant effect on the interlaminar stresses in composite laminates.
Application of Fractal Geometry on the Static Growing Crack of STS316 CT Specimen with a Side Groove
Yun, Yu-Seong ; Kwon, Oh-Heon ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 38~44
The application of fractal concept provides an useful method in the study for the quantitative analysis of irregular variations like the fracture surfaces and crack profiles. Fractal curves have characteristics that represents a self-similarity based on the fractal dimension. The fractal dimensions were obtained by the box counting method. In this report, we obtained the nearly stable fractal dimensions of fracture crack profiles for STS316 with CT specimen as the crack advances and the relationships between crack length and fractal dimension. Moreover fractal fracture parameter that corresponds to J-R curve is shown by the relationships between fractal dimension and crack extension. From the results, we concluded that crack extension of high toughness material also shows the fractal characteristics, which can be used in order to evaluate the crack life precisely.
Fracture Characteristics of Carbonized Silicon Grinding Wheels
Oh, Dong-Seuk ; Lee, Byong-Gon ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 45~51
In this study, the fracture characteristics of carbonized silicon grinding wheels were examined with tensile, compression, impact and bending test. The experiment was performed for the various grinding wheels with grain size #46, #80, and grade H, L, P, and one vitrified bond and one structure No.7. Also the centrifugal fracture rpm of carbonized silicon grinding wheels were measured and compared with the calculated values for the various wheel diameters and thicknesses. The results showed that the fracture tensile strength was
, and it was increased by decreasing grain size and increasing grade. The fracture compression loads were
, and the inner stress was higher than outer's. And the absorption energy of impact test was 3.3~4.7 J, and it was increased by decreasing grain size but it was not effected by grade. The fracture bending stress was
, and it was increased by decreasing grain size and increasing grade. The centrifugal fracture rpm of carbonized silicon grinding wheel was about 8,500~12,000 and agreed well with the calculated value, and it was increased by decreasing diameter. However, it was almost constant for the reduction of wheel thickness.
Criterion for Failure of Internally Wall Thinned Pipe Under a Combined Pressure and Bending Moment
Kim, Jin-Weon ; Park, Chi-Yong ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 52~60
Failure criterion is a parameter to represent the resistance to failure of locally wall thinned pipe, and it depends on material characteristics, defect geometry, applied loading type, and failure mode. Therefore, accurate prediction of integrity of wall thinned pipe requires a failure criterion adequately reflected the characteristics of defect shape and loading in the piping system. In the present study, the finite element analysis was performed and the results were compared with those of pipe experiment to develop a sound criterion for failure of internally wall thinned pipe subjected to combined pressure and bending loads. By comparing the predictions of failure to actual failure load and displacement, an appropriate criterion was investigated. From this investigation, it is concluded that true ultimate stress criterion is the most accurate to predict failure of wall thinned pipe under combined loads, but it is not conservative under some conditions. Engineering ultimate stress estimates the failure load and displacement reasonably for al conditions, although the predictions are less accurate compared with the results predicted by true ultimate stress criterion.
Investigation of Effects of Duct Thickness an Counterflow Flam Structure
Park, Woe-Chul ; Ko, Kyung-Chan ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 61~65
Nonpremixed counterflow flames at low strain rates,
, were numerically simulated to investigate the effects of the duct thickness on the flame structure in normal gravity. For small values of the duct thickness, the positions of the flame and stagnation point were highly sensitive to the duct thickness. When the duct thickness was greater than 6mm, however, the effects of the duct thickness on the flame structure were negligible. The computed temperature along the duct centerline agreed well with measurements.
Combustion Characteristics of the Miao-Gravity Condition
Lee, Keun-Oh ; Lee, Kyeong-Ook ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 66~70
The transient soot distributions within the region bounded by the droplet surface and the flame were measured using a full-filed light extinction technique and subsequent tomographic inversion using Abel transforms. The soot volume fraction results for n-heptane droplets represent the first quantitative assessment of the degree of sooting for isolated droplets burning under microgravity condition. The absence of buoyancy(which produces longer residence times) and the effects of thermophoresis produce a situation in which a significant concentration of soot is produced and accumulated into a soot-cloud. Results indicate that indeed the soot concentration within the microgravity droplet flames(with maximum soot volume fractions as high as ~60ppm) are significantly higher than corresponding values that are reports for normal-gravity flames. This increase in likely due to longer residence times and thermophoretic effects that manifested under microgravity conditions.
Evaluation of Thermal Degradation of 2.25Cr-1Mo Steel Using Ultrasonic Nonlinear Effect and X-ray Diffraction Method
Kim, Duk-Hee ; Park, Un-Su ; Park, Ik-Keun ; Byeon, Jai-Won ; Kwun, Sook-In ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 71~79
It was attempted to evaluate the degree of degradation of thermally aged 2.25-1Mo steek by ultrasonic monlinear parameter(UNP) measurement and X-ray diffraction analysis of extracted carbide. Artificial aging was performed to simulate the microstructural degradation in 2.25Cr-1Mo steel arising from long time exposure at
. Microstructural analysis (number of carbides per unit area) and measurements of mechanical properties(Vickers hardness, DBTT) and degradation evaluation parameters(UNP and intensity ration of X-ray diffraction peak of electrolytically extracted carbide) were performed. Both of UNP and intensity ratio of X-ray diffraction peak for M6C carbide to that of M23C6 carbide(IR) increased abruptly in the initial 1000 hour of aging and then changed little. UNP and IR were proposed as potential parameters to evaluate the degree of aging degradation of 2.25Cr-1Mo steel.
Analysis of Safety Management System between Inside and Outside County
Tae, Soon-Ho ; Kim, Yong-Soo ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 80~86
To reduce the nation from facing increasing industrial disasters following the grave foreign exchange crisis in 1997, this thesis compared inside with outside of the current country safety manager system, presented way about introduction to comprehensive safety management measures.
New Fuzzy Controller for High Performance of Induction Motor Drive
Chung, Dong-Hwa ; Lee, Jung-Chul ; Lee, Hong-Gyun ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 87~93
This paper is presented new fuzzy controller for high performance of induction motor drive. New fuzzy controller took out appropriate amounts of accumulated control input according to fuzzy described situations in addition to the incremental control input calculated by conventional direct fuzzy controller. The structures of the proposed controller was motivated by the problems of direct fuzzy controller. The direct controller was given generally inevitable overshoot when one tries to reduce rise time of response. The undesirable characteristics of the direct fuzzy controller are caused by integrating operation of the controller, even though the integrator itself is introduced to overcome steady state error in provide a thorough comparative insight into the behavior of induction motor drive with direct and new fuzzy speed controller. The validity of the comparative results is confirmed by the simulation results for induction motor drive system.
Experimental Investigation of the Electrostatic Discharge(ESD) Damage in Packaged Semiconductor Devices
Kim, Sang-Ryull ; Kim, Doo-Hyun ; Kang, Dong-Kyu ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 94~100
As the use of automatic handling equipment for sensitive semiconductor devices is rapidly increased, manufacturers of electronic components and equipments need to be more alert to the problem of electrostatic discharges(ESD). In order to analyze damage characteristics of semiconductor device damaged by ESD, this study adopts a new charged-device model(CDM), field-induced charged model(FCDM) simulator that is suitable for rapid, routine testing of semiconductor devices and provides a fast and inexpensive test that faithfully represents ESD hazards in plants. High voltage applied to the device under test is raised by the field of non-contacting electrodes in the FCDM simulator, which avoids premature device stressing and permits a faster test cycle. Discharge current and time are measured and calculated. The characteristics of electrostatic attenuation of domestic semiconductor devices are investigated to evaluate the ESD phenomena in the semiconductors. Also, the field charging mechanism, the device thresholds and failure modes are investigated and analyzed. The damaged devices obtained in the simulator are analyzed and evaluated by SEM. The results obtained in this paper can be used to prevent semiconductor devices form ESD hazards and be a foundation of research area and industry relevant to ESD phenomena.
Electrical Properties of Low Density Polyethylene Film by Superstructure Change
Shin, Jong-Yeol ; Shin, Hyun-Taek ; Lee, Soo-Won ; Hong, Jin-Woong ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 101~109
The electrical properties of polyethylene are changed by the superstructure. Such crystalline polymer as polyethylene or polypropylene changes crystallinity and products spherulite or trans-crystal when it is cooled slowly. In this study, after thermal treatment of LDPE at 100[
], in silicone oil for an hour, we made specimens in order of slow cooling, water cooling, quenching according to cooling speed. Also, to study the influence of electrical properties due to the superstructure change, we analyzed physical properties and performed dielectric breakdown experiments using DC and impulse voltage Moreover we measured space charges in bulk using Laser Induced Pressure Pulse(LIPP) method. Trap level of specimen is 0.064[eV] at the low temperature region 0.31[eV] at the high temperature region in DC dielectric strength, 0.03[eV] at the low temperature region 0.0925[eV] at the high temperature region in impulse dielectric strength. As its result shows that the quantity of charges induced from the electrode surface increases with applied voltage time, and the distribution of space charges in samples increases the quantity of charges in proportion to applied voltage.
Development of RBI Procedures and Implementation of a Software Based on API Code (II) - Semi-Quantitative Approach
Song, Jung-Soo ; Shim, Sang-Hoon ; Kwon, Jung-Rock ; Yoon, Kee-Bong ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 110~118
During the last ten years, the need has been increase for reducing maintenance cost for aged equipments are ensuring safety, efficiency and profitability of petrochemical and refinery plants. American Petroleum institute(API) developed a code, API 581 for proposing standard procedures of risk based inspection. Even though the API 581 code covers general RBI procedures, there must be some limitations. In this study, a semi-quantitative assessment algorithm for RBI based on the API 581 code was reconstructed for developing an RBI software. The user-friendly realRBI software is developed with a module for evaluation semi-quantitative risk category using the potential consequence factor and the likelihood factor. Also, inspection planning module for inspection time and inspection method for equipments are included.
A Study on the Evaluation of Indoor Air Environment in Super High-Rise Dwelling House
Park, Mi-Jin ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 119~125
The concept of dwelling space is tend to be changed not only to have reasonable mobility but also to have high quality of indoor air with psychologicaa satisfaction and comfortable. Moreover, recent constructed buildings have a big problem because of exhausted pollution gas and particles from building materials. More serious problem occurs from its high air tightness reducing the ventilation for saving the energy and superior adiabatic insulators to have high heat efficiency. Indoor air quality in super high-rise dwelling house was investigated by measuring pollutants such as
, HCHO, Offensive ordor. Subjective evaluation of residential environment is processed for the inhabitants who live in research space by testing environmental load in accordance with environment morphology, exterior environmental factor and post occupancy correlation and influence of attention.
Interrelationships of Fire and Explosion Properties for Chlorinated Hydrocarbons
Ha, Dong-Myeong ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 126~132
By using the reference data, the empirical equations which describe the interrelationships of explosion properties and physical properties of n-chlorinated hydrocarbons have been derived. The properties which have been correlated are the lower and upper explosive limits, the stoichiometric coefficients, the heats of combustion, the carbon numbers. Also, the new equations using the mathematical and statistical methods for predicting the temperature dependence of lower explosive limits(LEL) of chlorinated hydrocarbons on the basis of the literature data are proposed. The fire and explosion properties calculated by the proposed equations in this research were a good agrement with literature data within a few A.A.P.E.(Average Absolute Percent Error) and A.A.D.(Average Absolute Deviation.) From a given explosive properties, by using the proposed equations, it is possible to predict to the fire and explosion characteristics for the other chlorinated hydrocarbons.
A Development of Nontoxic Composite Latex Using
Seul, Soo-Duk ; Lee, Sun Ryong ; Lee, Nae-Woo ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 133~139
Core-shell polymers of inorganic/organic pair, which are consisted of both core and shell component, were synthesized by sequential emulsion polymerization using ethyl methacrylate (EMA) as a shell monomer and ammonium persulfate as initiator. We found that
core should be prepared by adding 2.0wt% SDBS(sodium dodecyl benzene sulfonate),
core/PEMA shell polymerization was carried out on the surface of
particle during EMA shell polymerization in the core-shell polymer preparation. The structure of core-shell polymer were investigated by measuring the degree on decomposition of
by HCI solution, thermal decomposition of polymer composite on thermogravimetric analyzer, glass transition temperature on differential scanning calorimeter, and morphology using scanning electron microscope.
Flash Points of Water+n-Propanol System Using Closed-Cup Measurement Apparatus
Ha, Dong-Myeong ; Choi, Yong-Chan ; Lee, Sung-Jin ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 140~145
The Flash Point is one of the most important combustible properties used to determine the potential for fire and explosion hazards of chemical materials. An accurate knowledge of the flash point is important in developing appropriate preventive and control measures in industrial fire protection. The lower flash points for the Water + n-Propanol systems were measured by using Pensky-Martens closed cup tester. The experimental data were compared with the values calculated by the laws of Raoult and van laar equation. The calculated values based on the van Laar equation were found to be better than those based on the Raoult's law.
Study on Plastic Deformation of Interior Support at the Continuous I-Beam Bridge
Chung, Kyung-Hee ; Kim, Jin-Sung ; Yang, Seung-Ie ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 146~152
The steel shows plastic deformation after the yield point exceeds. Because of overloads, the plastic deformation occurs at the interior support of a continuous bridge. The plastic deformation is concentrated at the interior support, and the permanence deformation at the interior support remains after loads pass. Because local yielding causes the positive moment at the interior support, it is called "auto moment". Auto moment redistributes the elastic moment. Because of redistribution, auto moment decreases the negative moment at the interior support of a continuous bridge. In this paper, the moment-rotation curve from Schalling is used. The Plastic rotation is computed by using Beam-line method, and auto moment is calculated based on the experiment curve. The design example is presented using limit state criterion.
Removal Method for a Deposit at Sewerage with Polymer Additives
Jeon, Chan-Yeal ; Oh, Yool-Kwon ; Hwang, Se-Joon ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 153~159
This experimental study is aimed to increasing the velocity in the sewerage and also development of easy removal method for a corrosion and sand in the flow pipe. And the result by the increasing the out flow per unit time, diameter of sewerage pipe is becoming small size, cut down the construction fee and the same time reducing the tubulent flow pattern in the flow pipe. As a result of detected experimental velocity signal from the probe in the test wall surface, reducing the pump power and increasing the out flow unit time. Apparent water velocity decreases as the value of void ratio increases depends on the varies center of pipe.
A Comparative Study on the Safety Management Level of Construction Companies
Son, Chang-Baek ; Hong, Sung-Ho ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 160~167
In order to prepare effective safety management program, the evaluation of safety management level must be implemented. But research efforts on the safety management in Korea are limited to evaluate large construction companies. This study is initiated with the purpose of understanding safety management system in medium- and small-sized construction companies. The study performed questionnaire survey with 54 large companies, 46 medium- and small-sized ones. Employing 'Management Safety Health Index' of Maekyung Economic Institute, 34 questionnaire items were chosen by 9 associated experts. Based on the questionnaire survey, analyses were performed to compare safety management level between large companies as well as medium- and small-sized ones.
A Study on the Effectual Making Schemes of the Safety Assessment for the Construction Works
Choi, Jin-oo ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 168~172
The Safety Assessment for Construction works is used in order to make the safety plans to protect calamities in construction sites. However in Korea it is problem that the Safety Assessment has strict and meaningless contents. So it is not used well. This study suggests the effectual making methods of the Safety Assessment to solve the problems which are found through investing serious calamities and interviewing experts.
A THERP Application for Assessing Human Error Rates
Jae, Moo-Sung ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 173~177
THERP (Technique for Human Error Rate Prediction) methodology has been widely used for probabilistic safety assessments. The NUREG report involving this methodology is also called the HRA handbook. The THERP assumes that all actions involved in implementing a task are considered as components. In this paper human error rates associated with maintenance are evaluated by the THERP methodology. A gas governor system is used as an example which is also a risky system like nuclear power plants. It is also demonstrated that this approach is flexible in that it can be applied to any operator actions related to test and maintenance.
Effects of External Load and Upper Extremity Postures on Perceived Discomfort
Kee, Do-Hyung ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 178~183
The purpose of this study was to quantitatively investigate the effects of external load upper extremity posture on perceived discomfort. An experiment was conducted for measuring discomfort scores depending upon external loads and upper extremity postures, in which the free modules and numeric estimate method of the magnitude estimation was adopted as a tool for obtaining discomfort ratings. The upper extremity postures were controlled by wrist flexion/extension, elbow foexion, shoulder flexion, and shoulder adduction/abduction. The results showed that all experimental variables except shoulder adduction/abduction were significant at
=0.01 or 0.05. The effect of external load was very much larger than that of upper extremity postures. Therefore, it is recommended that a new posture classification scheme taking effect of external load to into consideration be developed for quantifying postural load.
A Study on Safety Management for Aging Society
Chang, Seong-Rok ; Kim, Eun-A ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 184~188
According to a recent report, Korea first reached aging society in 2000 and it is forecasted that the number of aged people over 65 years old will increase form 7.13%(2000) to 14% or more of total population in Korea in 2022. As many aged peoples are employed as day labor under the financial circumstances after Korean Financial Crisis, it is critical that we should take safety control measures for them. Thus, this study focused on analyzing aged accidents in terms of their characteristics, based on the actual trend of industrial accidents from 1996 to 2001 and the applications of medical treatment for the affected or wounded in Busan metropolitan area for recent 3 years (1999 to 2001) in order to analyze accident characteristics to cope with emergent aging period. As a result of analyzing the above data by job type, it was found that the construction work amounted to 38% of total job type. This result implies that accidents of the aged often occurs in 3D jobs including construction works without reasonable automation, which requires us to establish some preventive policies against those accidents. Moreover, it is found that rapid increasing accidents such as upset or occupational diseases or damages are typically attributed to those in the aged, mainly because the aged employees over 55 years old often have disadvantageous physical conditions such as relatively degraded balance and muscular control ability comparing to the younger. Therefore, it recommended that we should make effective safety policies for the aged and actively apply those policies to them. Moreover, it is required that we should encourage them to actively participate in safety compliance through corresponding trainings.
Out-of-Plane Buckling Analysis of Curved Beams Using DQM
Kang, Ki-Jun ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 189~195
The differential quadrature method (DQM) is applied to computation of the eigenvalues of out-of-plane bucking of curved beams. Critical moments including the effect of radial stresses are calculated for a single-span wide-flange beam subjected to equal and opposite in-plane bending moments with various end conditions, and opening angles. Results are compared with existing exact solutions where available. The differential quadrature method gives good accuracy even when only a limited number of grid points is used. New results are given for two sets of boundary conditions not previously considered for this problem: clamped-clamped and clamped-simply supported ends.
Transmission Characteristics LonWorks/IP-based Virtual Device Network for Predictive Maintenance
Choi, Gi-Heung ;
Journal of the Korean Society of Safety , volume 17, issue 4, 2002, Pages 196~201
Web-based predictive maintenance (PM) utilizes Virtual Device Network (VDN). VDN inevitably the implementation of Distributed Monitoring and Control Networks (DMCN). In general, one needs to integrate fieldbus protocol and TCP/IP to realize DMCN over IP network or internet, which can be viewed as Virtual Device Network (VDN). Interoperability between devices and equipments is essential to enhance the quality and the performance of predictive maintenance (PM). This paper investigates the transmission characteristics of VDN and suggests a basic framework for web-based PM using DMCN over IP network.