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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 26, Issue 6 - Dec 2011
Volume 26, Issue 5 - Oct 2011
Volume 26, Issue 4 - Aug 2011
Volume 26, Issue 3 - Jun 2011
Volume 26, Issue 2 - Apr 2011
Volume 26, Issue 1 - Feb 2011
Selecting the target year
Water-hammer in the Pump Pipeline System with and without an Air-Chamber
Lee, Sun-Kon ; Yang, Cheol-Soo ;
Journal of the Korean Society of Safety , volume 26, issue 1, 2011, Pages 1~7
When the pumps stopped in the operation by the power failure, the hydraulic transients take place in the sudden change of a velocity of pipe line. Each and every water hammer problem shows the critical stage to be greatly affected the facts of safety and reliability in case of power failure. The field tests of the water hammer executed at Cheong-Yang booster pump station having an air chamber. The effects were studied by both the practical experiments and the CFD(Computational Fluid Dynamics : Surge 2008). The result states that the system with water hammering protection equipment was much safer when power failure happens. The following data by a computational fluid dynamic analysis are to be shown below, securing the system stability and integrity. (1) With water hammering protection equipment. (1) Change of pressure : Up to
in contrary to estimating
. (2) Change rate of water level : 52~33% in contrary to estimating 55~27%. (3) Note that the operational pressure of pump runs approx. 145 m, lowering 155 m of the regularity head of pump. (4) Note that the cycle of water hammering delays from 80 second to 100 second, together with easing the function of air value at the pneumatic lines. (2) Change of pressure without water hammering protection equipment : Approximate
. The comprehensive result says that the computational fluid dynamics analysis would match well with the practical field-test. It was able to predict Max. or Min. water hammering time in a piping system. This study aims effectively to alleviate water hammering in a pipe line to be installed with air chamber at the pumping station and results in making the stability of pump system in the end.
Optimum Design of High Voltage Fuse Holder with a Built-in Acoustic Absorber System
Jin, Yeung-Jun ; Lee, Hae-Won ; Hwang, Yu-Sub ;
Journal of the Korean Society of Safety , volume 26, issue 1, 2011, Pages 8~14
Noise and vibration are likely to disturb the sensory system of human body leading to psychological stress and thereby property damage. In this research, a cut out switch(COS) with a built-in acoustic absorber along with a COS fuse broken was developed to reduce percussion noise. This new system is based on a design approach that combines existing absorber systems: expansion type, resonator type, and acoustic absorber type silencer The noise performance of the new system was simulated using the
software under optimized parameters: the diameter of perforated plate 2 mm, the plate thickness 3 mm, the width of expansion room 25 mm, the impinging vortex room 14 mm, and the noise absorbtion room 10 mm. The results showed that it reduced noise by approximately 41.1 dB compared to the current systems available in the market. Furthermore, it showed reduced noise by approximately 12 dB more than a product with an acoustic absorber of the Fault Tamer(USA).
A Study on the Effect of the Shot Peening in SCM420H Planetary Gear
Ahn, In-Hyo ; Ahn, Min-Ju ; Lyu, Sung-Ki ;
Journal of the Korean Society of Safety , volume 26, issue 1, 2011, Pages 15~20
This study deals with the effect of the shot peening in SCM420H planetary gears. The hardness and roughness of the gear surface can be improved by shot blast and shot peening. there in, the shot peening techniques are welcomed especially as one of the physical surface improvement methods. The two treatments are used widely, because of the qualitative analysis of shot blast and shot peening has become possible and the surface treatment can be done with little costs compared with other surface improvement methods. Therefore, this study investigates the effects of shot blast and shot peening in surface shape. The fatigue strength test at a constant stress amplitude is performed by using an electrohydraulic serve-controlled pulsating tester. And fatigue test also explained characteristics of shot blast and shot peening of planetary gears.
An Investigation of the Extinction and Ignition Characteristics Using a Flame-Controlling Method
Oh, Chang-Bo ; Lee, Eui-Ju ; Hwang, Cheol-Hong ;
Journal of the Korean Society of Safety , volume 26, issue 1, 2011, Pages 21~26
Extinction and ignition characteristics of
-air counterflow diffusion flame were numerically investigated using a Flame-Controlling Method(FCM). A skeletal reaction mechanism, which adopts 17 species and 58 reactions, was used in the simulation. The extinction and ignition conditions of the
-air diffusion flames were investigated with varying the global strain rate. Upper and middle branches of S-curve for the peak temperature in the inverse of the global strain rate space were obtained with the FCM. The structures of diffusion flames in the upper and middle branches of S-curve were compared. It was found that the global strain rate was not correlated with the local strain rate well in the low global strain rate region. It is expected that the FCM is very useful to obtaining the extinction and ignition condition of diffusion flame, such as fires.
Countermeasures for Safety Management in Subcontractor Work at Construction Site using AHP Technique
Son, Ki-Sang ; Gal, Won-Mo ; Choi, Jea-Nam ; Song, In-Yong ;
Journal of the Korean Society of Safety , volume 26, issue 1, 2011, Pages 27~35
There are many countermeasures collected by field experts, safety managers with their subjective decisions, without analysis. Subcontractor does not know which one of those can be more defective countermeasures. More weighted countermeasures should be taken for subcontractor's economical aspects. But there are almost no measures with useful weight so that subcontractors can select some as they need more effective even though there are not many measures at construction sites. AHP technique has been introduced into the analysis of counter measures for subcontractor. Countermeasures which car collected from field-experienced safety engineers have been weighed with frequency rate saying how many responders selected. And then, they are analyzed by AHP Technique for making out relative important level of the countermeasures, by each step such as Direct, Indirect, Management level, and policy level, quantitatively. AHP level in the study is composed of two stories, not three stories, in order to make respondents easier when they are asked. At least 15-year-experienced expert are asked for AHP questionnaire.
Nonlinear Soil-Structure Interaction Analysis Considering Complicated Soil Profile
Park, Jang-Ho ;
Journal of the Korean Society of Safety , volume 26, issue 1, 2011, Pages 36~42
This paper presents a nonlinear soil-structure interaction analysis approach, which can consider precisely characteristics of structures, complicated soil profiles and nonlinear characteristics of soil. Although many methods have been developed to deal with the soil-structure interaction effects in past years, most of them are nearly unpractical since it is difficult to model complicated characteristics of structure and soil precisely. The presented approach overcomes the difficulties by adopting an maligned mesh generation approach and multi-linear model. The applicability of the proposed approach is validated and the effects of complicated characteristics of structure and soil on soil-structure interaction are investigated through the numerical example by the proposed nonlinear soil-structure interaction analysis approach.
Cost Estimation of Accidents in Auto-Glass Manufacturing Process
Lim, Hyeon-Kyo ; Lee, Seung-Hoon ;
Journal of the Korean Society of Safety , volume 26, issue 1, 2011, Pages 43~48
Estimation of accident costs would set a sound criterion on which invest judgement for work improvement would be decided. Unfortunately, however, the professional agency and most companies in Korea still adopt the conventional cost estimation method based on Heinrich's theory would not be applicable any more since it was developed about a century ago. This research was carried out to confirm the validity of conventional accident cost estimation method. With 110 accident cases occurred in an autoglass manufacturing plant for last 7 years, post-accident treatment procedure was simplified as a model with several phases, and practical costs were analyzed case by case. The results showed that, as expected, the company should the largest portion of loss due to accidents, and that mean indirect cost were 10.10(
) times as much as direct cost estimated by conventional method. Therefore, finally, accident types and items influenced much on accidents costs were analyzed and discussed.
Survey on Performance of the Risk Assessment of Musculoskeletal Disorders
Park, Jae-Hee ; Lee, In-Seok ; Kee, Do-Hyung ; Jung, Hwa-Shik ; Park, Jung-Keun ;
Journal of the Korean Society of Safety , volume 26, issue 1, 2011, Pages 49~57
A questionnaire study was carried out to understand the status of performing the risk assessment of work-related musculoskeletal disorders(WMDSs), which is the employers' legal responsibility when the employees are involved in doing tasks with risk factors. Employers or managers from 340 companies and the representative employees from 250 companies participated in the survey. According to the participated employers and employees, 35.0~46.2% of companies had performed the first risk assessment before the end of 2005. However, it is presumed that the real condition might not be as much as the result, because most companies were very reluctant to took part in the survey. It was found that the type of business and size of the company are the main factors affecting the performance of the risk assessment in terms of the performing ratio, method, and so on. The participants were positive in the thought that the assessment would be helpful in preventing msuculoskeletal disorders, while there was a little difference between the employers and employees in the thought that the assessment would be helpful in finding the injuries in the early stage. It was found that it is necessary to modify and improve the definition and criteria of the tasks to be examined in the assessment.
Effects of the Handle Width, Height and Horizontal Angle on the Pushing, Lifting and Twisting Forces Required for the Handling of Barrows
Kim, Kyoung-Ah ; Lee, Ho-Cheol ; Song, Young-Woong ;
Journal of the Korean Society of Safety , volume 26, issue 1, 2011, Pages 58~64
This study evaluated the effects of the handle width(shoulder width, 1.25
shoulder width, 1.5
shoulder width), height(3 levels : knee, medium, knuckle) and horizontal angle(
) on the pushing, lifting, and twisting strengths which were required for carrying single or two wheel barrows. Twelve healthy college students(male) participated in the experiment. In each experimental condition(
=18), the subjects exerted three forces(pushing, lifting, and twisting clockwise). The experimental conditions and three forces were tested in random order, and a minimum 2 minutes of rest was provided between exertions. Results showed that the mean and maximum pushing forces showed greater values when the horizontal angle was
(p=0.016). However, the three independent variables had no statistically significant effects on the lifting forces(p>0.1). The mean and maximum twisting forces increased as the handle width became larger(p<0.05). Also, there was a marginal effect of the horizontal angle(p=0.065) on the twisting force. From the results of this study, the horizontal angle of
and the wider handle width were suggested for the design of single-wheel barrows.
The Concept and Functional Objectives of the Urban Resilience for Disaster Management
Kim, Tae-Hyun ; Kim, Hyun-Ju ; Lee, Kye-June ;
Journal of the Korean Society of Safety , volume 26, issue 1, 2011, Pages 65~70
Resilience has been suggested as a new paradigm of disaster management which reduces losses against disasters under the uncertain circumstances. The purpose of this study is to define the concept and to set up the objectives of urban resilience for disaster management. The common concept and components of resilience were analyzed by examining recent studies on resilience. The resilience was defined as "a capacity of physical and social urban elements adapting and recovering against disaster for better condition" and the five objectives of resilience - Robustness, Redundancy, Resourcefulness, Rapidity, and Regional Competency - were derived from the review of literatures. The major disasters and accidents were analyzed focused on those objectives. The concept and objectives of urban resilience could be used as a guidance for disaster prevention planning and disaster management processes.