• Journal of Environmental Impact Assessment
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• v.11 no.4
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• pp.231-238
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• 2002

In this study we classified sediment types of tidal flat using Landsat-5 images. This is for groping the method which can analyze correctly various kinds of sediment faces through satellite images. This work was performed by referencing ground truth of sediment faces which was investigated in the field. With this data we classified Landsat-5 image of 1997's to grope a most suitable classification method. As a result, in case of south Kanghwa island area, it was the optimum way to compound band 4, 5, 7 of Landsat-5 TM imagery. And, this work classified 3 kinds of sediment faces - M(mud), sM(sandy mud) and (g)M(slightly gravelly mud) - in land and mixed water area. It is anticipated that if this method is applied to a image of extremely lower sea level time, it can classify the sediment types of a broad tidal flat area. This is expected to be a beginning of estimating the effect of sediment faces to the change of the tidal flat ecosystem.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.1
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• pp.7-13
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• 2023

This study investigated the criteria for evaluating the impact of artificial intelligence services. The study classified AI evaluation targets into two areas: AI service and AI technology, and identified influence, sustainability, efficiency, effectiveness, and appropriateness as potential evaluation criteria. The time aspect of AI service evaluation was divided into pre-evaluation and post-evaluation, with pre-evaluation focused on reviewing items during development and design. The AI service area was classified into public, private, and mixed forms, and the impact assessment was classified as vertical or horizontal. The application of AI services was divided into normative and regulatory aspects, and the purpose of the evaluation could be impact or process evaluation. The subject and field of the AI service could also be used for classification purposes. The results of this study can be used to support the creation of AI service impact policies and countermeasures. However, further research is needed to develop specific indicators based on the criteria identified in this study to evaluate the impact of AI services.

• Journal of the Korean association of regional geographers
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• v.20 no.4
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• pp.444-453
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• 2014

Inequality of environmental impact is forecast to deepen due to the damage of environmental risk by the interaction between environmental and social inequalities causing more harms to environmentally vulnerable population. This study assessed the integrated cumulative impact of Seoul using Environmental Health Screening Tool developed by Environmental Protection Agency of California. In order to screen vulnerable area to environmental health, 10 indexes have been selected according to the environmental burden of exposure to environment and public health effects, population characteristics of sensitive populations and socio-economic factors. As a result of assessment conducted on cumulative impact of Seoul for years 2009~2011 through Environmental Health Screening Tool, risk factor for districts of Gangseo and Gangnam of Seoul showed high - Gangseo area indicated high risk factor both in environmental burden and population characteristics, while Gangnam area appeared high in environmental burden. The result of survey will be able to suggest scientific basis to push through fair and effective environmental policy in consideration of environment vulnerable population.

• Atmosphere
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• v.28 no.2
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• pp.187-200
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• 2018

The heavy snowfall phenomenon with thunder and lightning occurred in Yeongdong coastal region on 20 January 2017. Amount of snow on that day was a maximum of 47 cm and was concentrated in a short time (2 hours) at the Yeongdong coastal area. The mechanism of thundersnow was investigated to describe in detail using observational data and numerical simulation (Weather Research and Forecast, WRF) applied lightning option. The results show that a convective cloud occurred at the Yeongdong coastal area. The east wind flow was generated and the pressure gradient force was maximized by the rapidly developed cyclone. The cold and dry air in the upper atmosphere has descended (so called tropopause folding) atmospheric lower layer at precipitation peak time (1200 LST). In addition, latent heat in the lower atmosphere layer and warm sea surface temperature caused thermal instability. The convective cloud caused by the strong thermal instability was developed up to 6 km at that time. And the backdoor cold front was determined by the change characteristics of meteorological elements and shear line in the east sea. Instability indexes such as Total totals Index (TT) and Lightning Potential Index (LPI) are also confirmed as one of good predictability indicates for the explosive precipitation of convective rainfall.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.477-487
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• 2011

The modified repeat-sales model is employed in this study in order to identify differentiating impacts of time-varying accessibility characteristics on housing price. The results demonstrate that accessibility measures have very differential impacts on housing price over time. The improvement of accessibility through newly built facilities and apartment complex has either increased or decreased housing price. For example, the new subway line 9 has positive impact on housing price nearby, therefore price gap between subway access area and the other parts has been increased. The impact of the wide area facilities such as shopping center and hospital are decreased because they can be used more easily by the new subway line before. However, the small service area facility such as elementary school doesn't lose their impact even though subway accessibility extremely increased. The results imply that new facilities in existing residential site can affect not only housing price but also the other facilities' impact of housing price.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.5
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• pp.835-842
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• 2002

In this paper, static and fatigue bending strengths and failure mechanisms of CFRP (carbon fiber reinforced plastics) laminates having impact damages have been evaluated. Composite laminates used for this experiment are CF/EPOXY orthotropy laminated plates, which have two-interfaces $[0^0_ 4/90^0_4]_{ sym}$. A steel ball launched by the air gun collides against CFRP laminates to generate impact damages. The damage growth during bending fatigue test is observed by the scanning acoustic microscope (SAM) and also, the fracture surfaces were observed by using the SEM (scanning electron microscope). In the case of impacted-side compression, fracture is propagated from the transverse crack generated near impact point. On the other hand, fracture is developed toward the impact point from the edge of interface-B delamination in the case of impacted-side tension. Eventually, failure mechanisms have been confirmed based on the observed delamination areas and fracture surfaces.

• Journal of Environmental Impact Assessment
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• v.4 no.3
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• pp.73-86
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• 1995

This paper demonstrates Environmental Impact Assessment (EIA) has to be applied for development projects with regard to the ecological, economical and social aspects before any decisions made in the project. Korea has confronted various environmental problems during the last fifteen years, even though EIA has been enacted since 1981. The role of impact assessment in planning and policy processes should be emphasized to investigate the magnitude and intensity of the adverse influences of economic development. In the Seoul Metropolitan Region, it is necessary to apply EIA all urban projects to reduce the adverse effects of urbanization. Special attention should be given to the climatological effects throughout the urbanization process in Korea to keep the urban area energy-efficient. This study intends not only to establish basic data for national-and regional-based land-use policy in the environmental aspects, but also to provide the basic data for the possible climate model (scenarios) that may provide spatial and temporal variability by analyzing the actual climatic record. There is a noticeable impact of urbanization on the atmospheric environment in the Seoul Metropolitan Region. In this sense, the climatic aspect must be taken into consideration in the process of EIA to mitigate the well-known climatic alterations of urbanization. Moreover, the techniques of assessment should be improved by developing geo-reference data sets to build models of the global climate in response to the man-made environmental change.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.89-92
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• 2001

Drop weight impact tests were performed to investigate the impact behavior of carbon fiber/epoxy composite laminates reinforced by short fibers and other interleaving materials. Characterization techniques, such as cross-sectional fractography and scanning acoustic microscopy, were employed quantitatively to assess the internal damage of some composite laminates. Scanning electron microscopy was used to observe impact damage and fracture modes on specimen fracture surfaces. The results show that composite laminates experience various types of fracture; delamination, intra-ply cracking, matrix cracking and fiber breakage depending on the interlayer materials. Among the composite laminates tested in this study, the composites reinforced by Zylon fibers showed very good impact damage resistance with medium level of damage, while the composites interleaved by poly(ethylene-co-acrylic acid) (PEEA) film is expected to deteriorate the bulk strength due to the reduction of fiber volume fraction, even though the damaged area is significantly reduced.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.240-244
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• 2005

In this study a simple model is developed that predicts impact damage in a composite laminate using an analytical model. The model uses a non-linear approximation method (Rayleigh-Ritz) and the large deflection plate theory to predict the number of failed plies and damage area in a quasi-isotropic composite circular plate (axisymmetric problem) due to a point impact load at its centre. It is assumed that the deformation due to a static transverse load is similar to that occurred in a low velocity impact. It is found that the model, despite its simplicity, is in good agreement with FEM predictions and experimental data for the deflection of the composite plate and gives a good estimate of the number of failed plies due to fibre breakage. The predicted damage zone could be used with a fracture mechanics model developed by the second investigator and co-workers to calculate the compression after impact strength of such laminates. This approach could save significant running time when compared to FEM solutions.

• Journal of Environmental Impact Assessment
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• v.18 no.3
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• pp.185-193
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• 2009

This study documented and diagnosed the status and problems of coastal dredging and offshore disposal of dredged sediments in South Korea to improve assessment procedures for marine environmental impacts and develop effective management systems. A total of $729({\times}10^6)m^3$ of coastal sediment was dredged in the harbors during the period of 2001-2008. Most of dredged sediment was disposed to the land dumping sites whereas ocean disposal accounted for less than 5%. Ocean disposal areas were especially concentrated to the exclusive economic zone (EEZ) in the southeast of Busan, which is not only an important fishing area for fishermen, but also considered to be spawning and nursery ground for some commercial fish species. To minimize negative impacts of dredging and ocean disposal of coastal sediment on marine ecosystem and potential strife among coastal users, we suggest 1) in development projects involving ocean disposal, it should be mandatory to propose careful reuse plans in the land, and 2) guidelines of environmental assessment and consequence management programs should be developed and implemented.