• Journal of Environmental Impact Assessment
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• v.14 no.5
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• pp.275-289
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• 2005

In Korea, health-related items under current EIA (Environmental Impact Assessment) system can only be found in the categories of hygiene and public health. However, environment and public health are not adequately connected and also health is underestimated even though health is an important component of environmental assessments. As a result, health is not well integrated within criteria for investigating the impacts on environment. International trends in HIA (Health Impact Assessment) to strengthen the connection between environment and health were investigated in this research. Definitions, functions, circumstances, and merits of HIA in foreign countries were compared. By collecting and analyzing international organizations' and other countries' data related with HIA and EIA, preceding conditions and execution plans were suggested to link EIA and HIA from SEA (Strategic Environmental Assessment) aspects and to successfully accomplish EIA in Korea. According to this research, EHIA (Environmental Health Impact Assessment) can predict and manage the results of economical development only under the principles of inhabitants' participation, sustainability, and social justice. EHIA should be modified and improved towards increasing regional and national capabilities. For this, preparation of adequate procedure is required to connect EIA and HIA.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.917-917
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• 2003

The auditory experiments based on the subjective annoyance responses were undertaken for the establishment of the adverb modifiers of the heavy-weight impact noises. The standard heavy weight impact noise, impact ball noise and adult walking noise were recorded by dummy head at a newly-built apartment and were presented to the subjects by headphones. The levels of the three impact noises were varied from 30 to 60㏈(A) and the subjects matched one of the adverb modifiers to each level of the noise sources. As a result, seven scale modifiers were established and the intervals between the modifiers were found as equal. In addition, it was found that the lower annoyance noise limits for the heavyweight impact, impact ball and walking were 40-45㏈ (L$\sub$I, Fmax. AW), which is 6㏈ lower than in the previous study. The background noise level was as low as 21㏈(A) in the test booth, therefore, the testing conditions need to be concerned for evaluation of floor impact noise.

• Journal of the Korean Society of Industry Convergence
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• v.4 no.3
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• pp.295-304
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• 2001

The hydrodynamic impact problem was studied from 1929 to recent. Especially, Impact pressure is important for the design of the ships and offshore structure and spacecrafts, and under weapons. A ship traveling at high speed or in heavy sea has its bow and bottom damaged by high pressure caused by impact with and detachment from the water surface. Considerable impact may also occur when large waves hit the cross member or deck plate of an offshore structure within the splash zone. Many engineering cases require consideration of impact pressure, the movement of objects and change of the flow field. This study was obtained the pressure distribution of a falling body that is deadrise angle $0^{\circ}$ and deadrise angle $5^{\circ}$ upon a water surface by the experiment with the impact machine. The theoretical equation was obtained the air region and the interface and the water region which devide 3 parties between the body and the water surface for an investigation of the complete phenomena. Pressure distributions and histories compare favorably with available experimental data. The numerical results are similar to the experimental results for the impact force type with Fo(1+$cos{\pi}t/tc$).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.203-207
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• 2014

According to the advanced study, Increase of ceiling air space could cause increase of floor impact sound by air-spring effect. So in this research, we studied the increase of floor impact sound caused by ceiling air space in apartment buildings. At first, we evaluated the change of floor impact noise in the condition of with or without ceiling air-space. And then we installed perforated ceiling systems and glass wool at ceiling area. we expected that perforated ceiling systems could prevent air-spring effect in ceiling space. As a result, ceiling air space caused increasement of floor heavy impact noise about 2~4dB. But perforated ceiling & sound-absorbing materials system could give us reduction of heavy floor impact noise about 3dB. So this systems could be a good alternative to obey national regulations, because it can reduce heavy impact noise additional to floating floor systems.

• Journal of the Korean Society of Safety
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• v.20 no.1 s.69
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• pp.75-80
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• 2005

In this paper, when CF/EPOXY laminates for high efficiency space structure are subjected to FOD(Foreign Object Damage), the effects of temperature change on the impact damages(inter laminar separation and transverse crack) of CF/EPOXY laminates and the relationship between residual life and impact damages ale experimentally investigated. Composite laminates used in this experiment are CF/EPOXY orthotropic laminated plates, which have two-interfaces $[0^{\circ}_6/90^{\circ}_6]S$ and four-interfaces $[0^{\circ}_3/90^{\circ}_6/0^{\circ}_3]S$. CF/EPOXY specimens with impact damages caused by a steel ball launched from the air gun were observed by the scanning acoustic microscope under room and high temperatures. In this experimental results, various relations were experimentally observed including the delamination area vs. temperature change, the bending strength vs. impact energy and the residual bending strength vs. impact damage of CF/EPOXY laminates. And as the temperature of CF/PEEK laminates increases, the delaminaion areas of impact-induced damages decrease linearly. A linear relationship between the impact energy and the delamination areas were observed. As the temperature of CF/PEEK laminates increases, the delamination areas decrease because of higher initial delaminatin damage energy.

• Journal of KSNVE
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• v.2 no.1
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• pp.21-31
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• 1992

In the previous paper, we report a practical floor impact sound level prediction method for a heavyweight impact source(Tire), soft impact source such as children jumping and running. According to these results, the calculated value and the measured value correspond comparatively well, regardless of differences in the floor structures. And the floor impact sound for a heavyweight impact source, soft source was strongly influenced by structural factors such as floor slab stiffness and peripheral support conditions. But the floor impact sound for a light impact source (Tapping machine), hard impact source was influenced by resilient layers, composed of multi-layer in floor structures. Thus, In this paper, 4 actual floor structures, all with differing resilient layers, were calculated using impedance method. When these calculation values were compared with the measured values, approximately all the values fell with one rank of the sound insulation grade, reference curve(L curve) by the JIS standard. So, a sample of measured values and calculated values from floor structures is presented to show the accuracy and appropriateness of the impedance method in domestic.

• Steel and Composite Structures
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• v.12 no.3
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• pp.207-230
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• 2012

Nowadays CFRP (Carbon Fiber Reinforced Polymer) became widely used materials for the strengthening and retrofitting of structures. Many experimental and analytical studies are encountered at literature about strengthening beams by using this kind of materials against static loads and cyclic loads such as earthquake or wind loading for investigating their behavior. But authors did not found any study about strengthening of RC beams by using CFRP against low velocity impact and investigating their behavior. For these reasons an experimental study is conducted on totally ten strengthened RC beams. Impact loading is applied on to specimens by using an impact loading system that is designed by authors. Investigated parameters were concrete compression strength and drop height. Two different sets of specimens with different concrete compression strength tested under the impact loading that are applied by dropping constant weight hammer from five different heights. The acceleration arises from the impact loading is measured against time. The change of velocity, displacement and energy are calculated for all specimens. The failure modes of the specimens with normal and high concrete compression strength are observed under the loading of constant weight impact hammer that are dropped from different heights. Impact behaviors of beams are positively affected from the strengthening with CFRP. Measured accelerations, the number of drops up to failure and dissipated energy are increased. Finite element analysis that are made by using ABAQUS software is used for the simulation of experiments, and model gave compatible results with experiments.

• Journal of Information Processing Systems
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• v.6 no.4
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• pp.597-608
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• 2010

Software evolution is an ongoing process carried out with the aim of extending base applications either for adding new functionalities or for adapting software to changing environments. This brings about the need for estimating and determining the overall impact of changes to a software system. In the last few decades many such change/impact analysis techniques have been developed to identify consequences of making changes to software systems. In this paper we propose a new approach of estimating change/impact analysis by classifying change based on type of change classification e.g. (a) nature and (b) extent of change propagation. The impact set produced consists of two dimensions of information: (a) statements affected by change propagation and (b) percentage i.e. statements affected in each category and involving the overall system. We also propose an algorithm for classifying the type of change. To establish confidence in effectiveness and efficiency we illustrate this technique with the help of an example. Results of our analysis are promising towards achieving the aim of the proposed endeavor to enhance change classification. The proposed dynamic technique for estimating impact sets and their percentage of impact will help software maintainers in performing selective regression testing by analyzing impact sets regarding the nature of change and change dependency.

• Journal of Environmental Impact Assessment
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• v.9 no.1
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• pp.25-37
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• 2000

This paper presents a study of hydrological and hydraulic model applications in environmental impact statements which were submitted during recent years in Korea. In many cases (almost 70 %), the hydrological and hydraulic changes were neglected from the impact identification processes, even if the proposed actions would cause significant impacts on those environmental items. In most cases where the hydrological and hydraulic impacts were predicted, simple equations were used as an impact prediction tool. Computer models were used in very few cases(5%). Even in these few cases, models were improperly applied and thus the predicted impacts would not be reliable. The improper applications and the impact neglections are attributed to the fact that there are no available model application guidelines as well as no requirements by the review agency. The effects of mitigation measures were not analyzed in most cases. Again, these can be attributed to no formal guidelines available for impact predictions until now. A brief guideline is presented in this paper. This study suggested that the model application should be required and guided in detail by the review agency. It is also suggested that the hydrological and hydraulic items shoud be integrated with the water quality predictions in future, since the non-point source pollution runoff is based on the hydrologic phenomena and the water quality reactions on the hydraulic nature.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3081-3086
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• 2015

Development of a extra-large hydraulic breaker, which could be used for a 100 ton-class excavator were carried out Hot-firing tests were carried out. Before designing a hydraulic breaker, the analysis method to predict the performance such as impact energy and impact rate were studied. Based on the analysis result, the design and manufacture of a extra-large hydraulic breaker were performed, and the breaker were confirmed to operate successfully. The data of impact energy and impact rate were measured during the operation of the breaker, and were compared with the analysis result. The analysis result of impact rate anticipated well the test data, but that of impact energy showed a large difference with the test data. The extra-large hydraulic breaker were successfully developed and the analysis method of impact energy will be updated taking into account friction, hydraulic circuit, etc.