• Journal of KSNVE
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• v.1 no.2
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• pp.115-120
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• 1991

The impact hammer is extensively used in experimental modal analysis as a means to provide force over a broad range of frequencies. The hammer mass and the impact head are often changed to achieve a desired impact time duration with its corresponding input frequency spectrum, these mass changes affect the performance and sensitivity of the force transducer employed to measure the impact force. Both a mathematical model describing the effects of impact head and hammer mass on the performance of the force transducer and experimental verification of this model are presented here.

• Journal of Environmental Impact Assessment
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• v.3 no.1
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• pp.31-41
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• 1994

The choice of economic development over environmental protection has been used to explain the decline in the quality of the environment in developing countries. The authors reject this explanation and propose a theory of negligence to explain this decline. They point to the advantages of environmental impact assessments in dealing with the problem of negligence and presents case studies from four countries. Organizational models for Environmental Impact Assessments in Developing Countries are proposed as useful policy measures.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.513-517
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• 2004

This study aims to evaluate factors of floor structure influencing to the floor impact sound. For this reasons, we measured the vibration of floor and the floor impact sound in moment flame structure. The main results from this study are that slab area and thickness are critical factors of the floor impact sound and aspect ratio slab is not verified in flor impact sound.

• Structural Engineering and Mechanics
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• v.60 no.2
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• pp.211-223
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• 2016

Static loading and fluid impact tests on plates containing mesh reinforcement and polypropylene fibers in ratios of 0 to 3% by volume were performed. The objective was to observe the effect of fluid mass on the total impulse that caused the impact event and the influence of fiber amount on the impact resistance, and to estimate the velocity of fluid that causes scabbing, perforation or total disintegration. The study is the first to express the fluid impact resistance of polypropylene fiber reinforced concrete plates.

• Structural Engineering and Mechanics
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• v.32 no.5
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• pp.685-699
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• 2009

Current research and development of high performance concrete, together with study of phenomena that are pertinent to impact resistance, have lead to a new generation of barriers with improved properties to resist impact loads. The paper reviews major properties and mechanisms that affect impact resistance of concrete barriers as per criteria that characterize the resistance. These criteria are the perforation limit, penetration depth and the amount of front and rear face damage. From the long-known, single strength parameter that used to represent the barriers' impact resistance, more of the concrete mix ingredients are now considered to be effective in determining it. It is shown that the size and hardness of the aggregates, use of steel fibers and micro-silica have different effects on performance under impact and on the resistance. Additional pertinent phenomena, such as the rate and size effects, confinement and local versus global response, are pointed out with their reference to possible future developments in the design of impact resisting concrete barriers.

• Journal of Environmental Impact Assessment
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• v.4 no.3
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• pp.63-71
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• 1995

This study analyzes the problems of environmental laws, development planning laws, Metropolitan Area Development Planning (MADP), and the level of environmental pollution at Asan-bay metropolitan area, where MADP will be realized in the near future. In order to prevent environmental pollution by the implementation of MADP, the Environmental Impact Assessment (EIA) Act and EIA systems in Korea should be revised so as to reflect the followings. First, the impact of national landuse planning changes on the environment should be considered at the beginning of the EIA procedures. Second, the overlapping and greater impact of many projects upon surrounding metropolitan areas should be simultaneously evaluated, though each project is the subject of EIA, and the environmental pollution protection and abatement alternatives must be made in accordance with the above impact of the projects. Thirdly, total effluent regulation of water pollution, air pollution and solid wastes should be enforced based on the self-purification of the metropolitan area environment.

• Journal of Environmental Impact Assessment
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• v.4 no.3
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• pp.95-102
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• 1995

Environmental Impact Assessment (EIA) in Korea has worked toward environmental conservation and decision making since the Environmental Impact Statement of 1981. In order to implement the EIA process effectively, we have developed a system for and various methods of EIA. Among these methods, the Environmental Information System, which was introduced recently in Korea, can be used to integrate geographic and attribute data effectively. This study includes methods by which we may use the Environmental Information System. First of all, it explains building EIA factors on the natural environment, the living environment, and the socio-economic environment defined by Environmental Impact Statement regulations in Korea. This study also presents some applications of the assessment methods concerning suitability analysis of landfill sites. Finally, it shows the effectiveness of the Environmental Information System in odor impact assessment. Based on these analysis, the study makes some conclusions for the applications of the Environmental Information System.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.441-446
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• 2004

Mechanical systems with rubber parts have been used widely in industry fields. The evaluation of the physical characteristics of rubber is important in rubber application. Rubber material is useful to machine component for excellent shock absorbing characteristics. The impact characteristics of rubber were examined by experimental and finite element method. The impact test was conducted with a free-drop type impact tester. The ABAQUS/Explicit was used for finite element analysis. The effects of thickness and diameter of the cylindrical rubber structures were investigated. The impact absorbing ratio of the rubber material was studied order to compare the peak reaction force of the specimen which only contained aluminum against the specimen with the inserted rubber part.

• Journal of Environmental Impact Assessment
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• v.2 no.2
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• pp.33-39
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• 1993

Public participation in the Environmental Impact Assessment(EIA) has been implemented since the August 1 of 1991 with the Environmental Policy Act promulgation in the August 1 of 1991. It is structured to comment on draft Environmental Impact Statement(EIS) through open reviewing, public meeting and hearing. Though public participation has an important role in determining environmental significance, it is room for improvement. With positive public participation and system development such as Environmental Impact Assessment Act on June 11 of 1993, the effectiveness of it will be improved. This article is composed of status of public participation, comparison with other countries, comparison analysis by items of EIS prepared before and after public participation, and contents of public opinions in EIS.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.3
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• pp.176-184
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• 2002

The door stiffness is one of the important factors for the side impact. Generally, the researches have been conducted on the assembled door. A side impact door beam is installed in a door to protect occupants from the side impact. This research is only concentrated on the side impact beam and a side impact beam is designed. The cross section is defined to have an elliptic shape. An optimization problem is defined to find the design maximizing the intrusion stiffness within the specified weight. Design variables are the radii and the thickness of the ellipsoid. The analysis of the side impact is carried out by the nonlinear finite element method. The optimization problem is solved by two methods. One is the experimental design scheme using an orthogonal array. The other is the gradient-based optimization using the response surface method(RSM). Both methods have obtained the better designs than the current one.