• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.729-732
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• 2003

Security and privacy issues complicate wireless local area network deployment. for a wired network, certain levels of security are maintained since access to the physical medium is restricted to the devices physically connected to the network. Though wireless local area networks offer some built-in security features, security breaches are possible if appropriate precautions are not taken. This paper describes security issues related to wireless local area networks and presents a software approach for restricting and controlling wireless access. The system authenticates users on the basis of identity, privileges and access hardware by distributed software agents that implement security policy and restrict unauthorized access.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.5
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• pp.539-544
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• 2000

A simple analytic model is proposed here to analyze the concentration deficit field caused by a large area of vegetated area. With non-dimensional deposition velocity chosen as small parameter, the regular perturbation method is exploited to derive the mass balance equation and the dynamic equations for the concentration deficit field, Analytic solutions to those equations are obtained in a closed form for several cases of interest, assuming that the concentration field is stationary and the plume can be nicely approximated as Gaussian for a point source. The results suggest that quite a negligible fraction (less than 1%) of the gaseous air pollutants emitted into the air is removed by the vegetated area of which width is 4 km in wind-wise direction, the typical dimension of the Restricted Development Zones around the metropolitan regions in South Korea.

• Journal of the Korean earth science society
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• v.28 no.5
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• pp.563-571
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• 2007

Adelograptus brevibrachiatus sp. novo is erected for materials previously referred to as Adelograptus cf. tenellus from the circum-Pacific area. The species shares many morphological characteristics with Adelograptus tenellus from Europe but differs from it by possessing typically short stipe lengths throughout rhabdosome due to less thecal density along the stipes. Taxonomic characteristics of A. cf. tenellus reported from circum-Pacific area are compared with each other. The paleogeographic distribution of A. tenellus seems to be restricted within Europe, while that of A. brevibrachiatus within circum-Pacific area.

• Economic and Environmental Geology
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• v.18 no.1
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• pp.23-39
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• 1985

The northeastern part of Ogcheon zone which consisted mainly of Cambro-Ordovician arenaceous, argillaceous and calcareous formations and Carboni-Triassic arenaceous and argillaceous formations is delineated as the eastern mass of a thrust fault along Choongju-Moongyong-Cheongsan in the middle of the zone. The present study proposes a geotectonic line, Imgye-Samchog fault(see, figure 1) which divides the northeastern part into two blocks, Hambacksan block in the west and East coast block in the east. The igneous rocks in the Hambacksan block ranging from granite to gabbro are distributed in a symmetrical zones parallel to general direction of Ogcheon zone as follows (Fig. 2 and Table 2). Southeast igneous rock zone: it aligns Jurassic granites in its south and Precambrian leucocratic granites in its north. Central igneous rock zone: it aligns Cretaceous granites in its south and Jurassic granites, and some of diorite and gabbro in its north. Northwest igneous rock zone: aligns Jurassic granites in its south and huge batholithic granodiorite in its north. The distribution of the igneous rocks in the East coast block shows an entirely different features from those of Hanbacksan block. In the southern part of the block they assemble in a narrow area ranging in age from Early Proterozoic, through Middle to Late Proterozoic, Devonian, Jurassic, Cretaceous to Tertiary, whereas, the igneous rocks in the northern part of the block gathered to a restricted area, in ages of Middle Proterozoic and Cretaceous. The assemblage of the igneous rocks in the studied area shows a compositionally restricted, mixed S-type and I-type granites, $^{87}Sr/^{86}Sr$ > 0.706, rare volcanics and shortening with upright folding. These lithologic and structural features suggest that the igneous activity in this part related intimately to Hercynotype Orogeny of Pitcher(1979). Chronological episodes of igneous activity from Early Proterozoic to Early Tertiary in the northeastern part are figured.

• Journal of Soil and Groundwater Environment
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• v.6 no.4
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• pp.97-112
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• 2001

The Section 12 of Groundwater Law stipulates that groundwater conservation zone should be regulated by the designation of conservation area and development restricted area, The most important policy for groundwater conservation and protection is to estimate and designate groundwater conservation zone. The groundwater classification map is utilized to determine the prime groundwater conservation areas, which delineate the first and the second ranked conservation areas of the map. According to the classification method of the Ministry of Construction and Transportation in 2000, groundwater quality for groundwater classification is classified with 4 levels based on the following conditions : (1) the present groundwater quality; (2) the potential usage as drinking water at present and in the future; (3) hydrogeological characteristics, and (4) the existence of pollution sources and activities. Throughout the initial analysis, the groundwater conservation areas are represented about 57.1$\textrm{km}^2$ in the groundwater classification map, which is 9.4% of Seoul Metropolitan Area. The management guidelines for groundwater conservation area are also developed referring to Cheju Province Groundwater Conservation Management Project and the guidelines by the Ministry of Construction and Transportation. But the specific administration and detailed technical survey should be prepared to efficiently manage the groundwater conservation area.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.3
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• pp.75-83
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• 2001

This study selected Yangpyung as a target site because Yangpyung is a area of high value blessed with well preserved natural resources and beautiful natural scene and where thoughtless development and malformed use of land are in progress under the mask of hotel, accommodations and sales facility which fits the interests of land owner. As for the method used for this study, I inquired into domestic/international instances and the concept of existing environmental indicators and assessment of suitability with a view to establish assessment indicators and pose the concept through theoretical investigation of green-network and to establish green-network. 17 articles of environmental indicators such as aspect analysis, contour, greenbelt, DEM, NDVI, nature conservation area, reservoir and area for the promotion of agriculture were chosen as a actual analysing n data for setting up assessment indicators. From the result of analysis, as anticipated, green zone in Yongmusan areas within Youngmun and Seojong areas were the center of green-network in the wide area green-network in Yangpyung and the restricted area by basin system, road and legal regulation was selected as spot area and finally arable land and reservoir were selected as base which connects core with spot.

• KCID journal
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• v.12 no.1
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• pp.28-37
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• 2005

Although experimental analysis for groundwater sample at wells located systematically are very effective to delineate seawater intrusion region at coastal area, this method is restricted in few wells and time. We have conducted electrical resistivity soun

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.363-364
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• 2015

On the area which is restricted an unauthorized WiFi service, mobile WiFi hotspot causes security problems like leaking and gathering internal data. In this paper, we modify a wireless lan driver and implement a detector that periodically scans the wireless channels.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1998.04a
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• pp.66-70
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• 1998

The Chirisan earthquake occurred on July 4, 1936 was the largest earthquake known to have occurred in Southern Korean in the twentieth century. After, the magnitude of the earthquake was estimated to be ML = 5.0. It was recorded at eleven seismological stations and tremors were felt throughout the Southen Peninsula. However, damages were restricted in relatively narrow area including the SSangysa Temple and nearby town Sukmoon. Fairy detailed report(Hayata, 1940) was published and some reserches based on the report have been performed. The present study briefly introduces damages and researches corresponding the earthquake. Intensity attenuation and peak ground acceleration are also evaluated.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.299-300
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• 2006

In this paper, we propose a segmentation algorithm which combines the ideas from local watershed transforms and the region merging algorithm based hierarchical queue. Only the process of watershed and region merging algorithm can be restricted area. A fast region merging approach is proposed to extract the video object from the regions of watershed segmentation. Results show the effectiveness and convenience of the approach.