• Proceedings of the Korean Institute of Building Construction Conference
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• 2004.05a
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• pp.5-10
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• 2004

Apartment Buildings have particularity to cluster together, especially, floor is close to resident, it is subject to dissatisfaction about impact noise between up and down floors. However, we require standard for counterplan to reduce the impact noise of floor. In point of fact, it difficult to objective evaluate for performance sound insulation that not physical sound volume but orignal form, means and effect of sound caused to complex noise in apartment house. Unique type of dwelling and structure pattern cause to noise of floor impact which is established by law for standard regulation. It is object to analysis and compare the result of performance sound insulation of upper floor impact and sample construct the subject resilient material of sound insulator

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.197-202
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• 2002

The most common failure of breakwater comes from impact wave pressure generated by intense storms. This impact pressure is 10 folds greater than the pressure generated by normal waves. Therefore, the precise knowledge of magnitude of impact wave pressure applied on breakwater and its structural response is crucial for the economical and safe design. However, presently, a precise analysis of breakwater is restricted by insufficient and incorrect consideration of the effect of soil-structure Interaction. 3 major research areas included in this study are (1) theoretical analysis of impact wave pressure, (2) selection of breakwater structure model (3) soil-structure interaction analysis using limit analysis computer program. Based on this analysis, predicted response of concrete breakwater and probable failure location under wave impact pressure are determined.

• Journal of Korean Society of Rural Planning
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• v.9 no.4 s.21
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• pp.9-18
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• 2003

The objectives of the study are to improve techniques for social impact assessment and to suggest their measuring methods to apply in small scale rural development projects. Population, residence, industries, and traffic volumes were selected to measure the social and economic impact assessment of Seongeup agricultural water development project in Jeju Province. Existing data gathering methods were used to estimate the changes of population and traffic volumes. Interview schedule for villagers was applied to estimate the residents' satisfaction to living environments. Interview schedule for experts was applied to estimate agricultural productivity and land price. The results of social and economic impact assessment show that there will be considerable changes in living environments, agricultural productivity, and land price. On the contrary, the project will make little impacts on the changes of population, em-ployment, and traffic volumes.

• International Journal of Aeronautical and Space Sciences
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• v.4 no.2
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• pp.26-36
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• 2003

The objective of this study is to enhance neural-network guidance to consider the impact condition. The optimal impact condition in this study is defined as an head-on attack. Missile impact-angle error, which is a measure of the degree to which the missile is not steering for a head-on attack, can also have an influence on the final miss distance. Therefore midcourse guidance is used to navigate the missile, reducing the deviation angle from head on, given some constraints on the missile g performance. A coordinate transformation is introduced to simplify the three-dimensional guidance law and, consequently, to reduce training data. Computer simulation results show that the neural-network guidance law with the coordinate transformation reduces impact-angle errors effectively.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.403-404
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• 2010

This paper introduces new impact apparatus using elastic strain energy for Fiber Reinforced Cementitious Composites [HPFRCC] which requires larger size of specimen and higher impact load and energy to fail the specimens. New impact apparatus utilize elastic strain energy to generate high rate impact stress wave and it is much smaller, cheaper and safer than current other impact devices.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.11
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• pp.112-119
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• 1996

Impact ionization model in GaAs has been presented by modified keldysh formula with two sets of power exponent of 7.8 and 5.6 in study. Impact ionization rate is derived from fermil's golden rule and ful lenergy band stucture based on empirical pseudopotential method. Impact ionization rates show anisotropic property in low energy region (<3eV), but isotropic in high energy region (3>eV). Full band monte calo simulator is coded for investigating the validity of the GaAs impact ionization model, and validity is checked by comparing impact ionization coefficients with experimental values and ones in anisotropic model. Valley transitions to energy alteration are explained by investigating electron motion in brillouin zone for full band model to electric field variation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.161-162
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• 2018

In this study, it evaluate the impact resistance of UHPC by repeated impact. smooth steel fiber and polyvinyl alcohol fiber were reinforced in UHPC respectively. Overall, the impact resistance of the specimens reinforced with 0.4vol.% PVA fiber was high, and the crater diameter was small in specimens using 13mm fiber. When 19 mm steel fiber is used, the fracture depth is small due to the increase of macro crack resistance compared with other specimens. On the other hand, in the case of the fracture area, it is considered that the use of the fiber of 13 mm causes an increase in the stress dispersion effect to occur small.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.4
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• pp.520-527
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• 2010

The kill probability of a missile depends on guidance error, warhead performance, and etc. In this paper, we analyzed the kill probability of anti-tank missile in a new approach. Under the condition that the missile hit the target, we studied the effect of angle of attack and impact angle. High impact angle increase the probability that the missile hits the upper armour which is relatively weaker, while high angle of attack at the impact instant decreases the effectiveness of the jet induced by the warhead. We proposed a way to increase the capability of penetration by analyzing the interrelation between impact angle and angle of attack.

• Journal of the Korean Society for Nondestructive Testing
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• v.12 no.2
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• pp.21-29
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• 1992

Acceleration signal characteristics of a steel plate, impacted by steel balls, were studied in an attempt to apply the experimental results to the impact location and mass estimation of metallic loose parts in the cooling system of nuclear power plants. Experimental results show that the variation of maximum acceleration amplitude and impact contact time due to the change of ball mass and impact velocity can be well explained by the Hertz impact theory. The frequency spectral pattern shifted slightly in spite of the increase of impact velocity and impact location. Ball mass, however, strongly affected the frequency spectral pattern. Hence the frequency spectrum can be used for estimation of the mass of unknown loose parts in the cooling system.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.1
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• pp.55-62
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• 2008

This study investigated the status and problems of marine-related environmental impact assessment and a utilization-consultation system in Korea and suggested improvement of the review organization. Also, it conducted SWOT analysis based on evaluation of functions, roles and performance of the marine environmental impact assessment center and proposed development strategies of the center through introduction of expert opinions and advanced systems. The performance statement-review by the center in 2007 included 358 cases in total; 165 (46.1%) for consultation on utilization of sea area, 104 for environmental impact assessment (29.0%), and 89 (24.9%) for prior environmental review. The consultation on utilization of sea area can be divided into that for public water surface-use (41%) and reclamation (32%), and sea aggregate extraction process (21%). Although bad impacts on marine environment are reducing under the current system, there are some limits and problems to supplement it in terms of content, system and operation. Review system on sea area utilization-impact(marine environmental impact assessment center) by marine environmental management law needs to obtain expertise, fairness and efficiency and, to do so, have operational supports and institutional improvement to maximize its own functions and roles. At the same time, it is necessary for the center to establish identity and the status as a professional review organization by setting active development strategies inside the center. Finally, it should strengthen an consultation system of marine environmental impact assessment led by the related ministry to achieve effective coastal management.