• Journal of the Korean earth science society
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• v.24 no.1
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• pp.46-60
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• 2003

In Namyang Bay of western Korea, macrotidal-flat deposits are divisible into three late Quaternary units: Unit M1 of upper marine mud, Unit T1 of middle siderite-bearing terrestrial clay, and Unit M2 of lower marine mud. Unit M1 represents typical Holocene intertidal mudflat deposits, showing a coarsening-upward textural trend. It probably resulted from the continual retrogradation of tidal flat during the mid-to-late Holocene sea-level rise. Reddish brown-color Unit T1 consists of homogeneous clay with abundant freshwater siderite grains and plant remains. Unit T1 is clearly separated from the overlying Unit M1 by a sharp lithologic boundary. Radiocarbon age, siderite grains and lithologic features indicate that Unit T1 is originated from freshwater bog or swamp deposition infilling the localized topographic lows during the early Holocene age. Overlain unconformably by early Holocene swamp clay, Unit M2 is orange to yellow in color and mottled, suggesting significant degree of weathering during the sea-level lowstand. Such subaerial oxidation is confirmed in the vertical profiles of geotechnical properties, clay mineral assemblages and magnetic susceptibility. Unit M2 appears to be correlated with the upper part of the late Pleistocene tidal deposits developed along the western Korean coast. The sedimentary succession of the Namyang-Bay tidal-flat deposit provides stratigraphic information for the Holocene-late Pleistocene unconformity and also permits an assessment of the preservation potential of the late Pleistocene marginal marine deposit along the western coast of Korea.

• Journal of Korean Society of Rural Planning
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• v.17 no.3
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• pp.81-90
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• 2011

The altitude criteria of 'Management of Mountains District Act' and 'National Land Planning and Utilization Act' are different because the adaptive reuse permissions on mountains district by two acts have been operated individually and each criteria has some problems for application. This study aims to suggest proposals for improvements of altitude criteria by two acts. The altitude criteria of the duel legal systems were researched by literature review and inherent issues were derived by interview with public officers and GIS tools applied to cases. The results are as follows : First, duel criteria systems need to be integrated based on the format by 'Management of Mountains District Act'. Second, the criteria index(50/100) by 'Management of Mountains District Act' need to be adjusted due to the preserved area ratio in mountains district and the each definition of 'the peak point of the mountain' and 'the tail of the mountain' can be changed as 'the highest point within the same slope(including ridge)' and as 'the average of the highest and the lowest point on boundary between the mountain district and the other land use district'. Third, the method of slope division may be determined by the conditions of local areas and the discrepancy between the two slopes in common boundaries must be adjusted. Finally, the maps containing preservation areas and development areas need to be notified.

• Journal of Computing Science and Engineering
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• v.5 no.3
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• pp.210-222
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• 2011

In this work, we study the problem of privacy-preservation data publishing in moving objects databases. In particular, the trajectory of a mobile user in a plane is no longer a polyline in a two-dimensional space, instead it is a two-dimensional surface of fixed width $2A_{min}$, where $A_{min}$ defines the semi-diameter of the minimum spatial circular extent that must replace the real location of the mobile user on the XY-plane, in the anonymized (kNN) request. The desired anonymity is not achieved and the entire system becomes vulnerable to attackers, since a malicious attacker can observe that during the time, many of the neighbors' ids change, except for a small number of users. Thus, we reinforce the privacy model by clustering the mobile users according to their motion patterns in (u, ${\theta}$) plane, where u and ${\theta}$ define the velocity measure and the motion direction (angle) respectively. In this case, the anonymized (kNN) request looks up neighbors, who belong to the same cluster with the mobile requester in (u, ${\theta}$) space: Thus, we know that the trajectory of the k-anonymous mobile user is within this surface, but we do not know exactly where. We transform the surface's boundary poly-lines to dual points and we focus on the information distortion introduced by this space translation. We develop a set of efficient spatiotemporal access methods and we experimentally measure the impact of information distortion by comparing the performance results of the same spatiotemporal range queries executed on the original database and on the anonymized one.

• Nuclear Engineering and Technology
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• v.44 no.7
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• pp.735-744
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• 2012

In order to quantify the flow distribution characteristics of APR+ reactor, a test was performed on a test facility, ACOP ($\underline{A}$PR+ $\underline{C}$ore Flow & $\underline{P}$ressure Test Facility), having a length scale of 1/5 referring to the prototype plant. The major parameters are core inlet flow and outlet pressure distribution and sectional pressure drops along the major flow path inside reactor vessel. To preserve the flow characteristics of prototype plant, the test facility was designed based on a preservation of major flow path geometry. An Euler number is considered as primary dimensionless parameter, which is conserved with a 1/40.9 of Reynolds number scaling ratio. ACOP simplifies each fuel assembly into a hydraulic simulator having the same axial flow resistance and lateral cross flow characteristics. In order to supply boundary condition to estimate thermal margins of the reactor, the distribution of inlet core flow and core exit pressure were measured in each of 257 fuel assembly simulators. In total, 584 points of static pressure and differential pressures were measured with a limited number of differential pressure transmitters by developing a sequential operation system of valves. In the current study, reactor flow characteristics under the balanced four-cold leg flow conditions at each of the cold legs were quantified, which is a part of the test matrix composing the APR+ flow distribution test program. The final identification of the reactor flow distribution was obtained by ensemble averaging 15 independent test data. The details of the design of the test facility, experiment, and data analysis are included in the current paper.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.1
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• pp.67-79
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• 2001

According to the new general movement of ESSD in Korea, the role, background, and subjects, etc. of Ecological Restoration Area were studied to find out the way for this area to be settled as one kind of industry. Questionnaire and literature study were carried out to understand and to find out the way of the area settlement with the conceptual and practical definition of it. The related sub-areas studied were 1. regulations and standards including design and construction 2. researches and developments around the area 3. related curriculums applying in the educational organizations 4. present situation of the industry. Followings are the results of this study and several proposals for the area to be settled in Korea with the other related areas. 1. The boundary of Ecological Restoration could be defined as the concept of preservation(or conservation) and restoration of the ecosystem with ecological planting - including the restoration strategies for the areas of slope, artificial foundations, watersides and wetlands, with in bio-diversity and eco-forests for these areas. 2. It seems that the more investments needed for the elaborate and professional techniques to be developed for the design and construction works to the contrary that the base of this area be matured already in the several sub-areas. 3. For the successful work of Environmental Restoration, defining the new industrial branch -independent from existing construction industry- is recommended through the law system under the control of the Ministry of Environment. It will be better if professional officer system in governmental organization could follow up this. 4. Educational organization and Technical expert qualifying system to train the Ecological Restoration Professionals should be induced for the effective practice of the area.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.5 no.4
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• pp.286-290
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• 2005

We consider the poisson equation where the functions involved are periodic including the solution function. Let $R=[0,1]{\times}[0,l]{\times}[0,1]$ be the region of interest and let $\phi$(x,y,z) be an arbitrary periodic function defined in the region R such that $\phi$(x,y,z) satisfies $\phi$(x+1, y, z)=$\phi$(x, y+1, z)=$\phi$(x, y, z+1)=$\phi$(x,y,z) for all x,y,z. We describe a very simple method for solving the equation ${\nabla}^2u(x, y, z)$ = $\phi$(x, y, z) based on the cubic spline interpolation of u(x, y, z); using the requirement that each interval [0,1] is a multiple of the period in the corresponding coordinates, the Laplacian operator applied to the cubic spline interpolation of u(x, y, z) can be replaced by a square matrix. The solution can then be computed simply by multiplying $\phi$(x, y, z) by the inverse of this matrix. A description on how the storage of nearly a Giga byte for $20{\times}20{\times}20$ nodes, equivalent to a $8000{\times}8000$ matrix is handled by using the fuzzy rule table method and a description on how the shape preserving property of the Laplacian operator will be affected by this approximation are included.

• Korean Journal of Plant Resources
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• v.24 no.4
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• pp.395-403
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• 2011

This study was conducted to investigate the habitat positional environment and vegetation properties of Mankyua chejuense. The habitats were classified into two types depending on the depth of the habitat, the ratio of rock exposure, the dominant species and the surrounding vegetation, which affected the vegetation of the habitats. The habitats with a high ratio of rock exposure showed a distinctive geographical boundary to the adjacent region and most of them were composed of trees that grow in humid environment. On the contrary, in the soil-rich habitats, the depth was shallow, soil layer was well developed, and the trees were introduced from the adjacent areas. However, the dominant species in the herbaceous layer were aquatic plants, which indicated that the habitats had the properties of wetland. Therefore, it was found that thes habitats of Mankyua chejuense have the properties similar to those of marshland. For the preservation of Mankyua chejuense, it is very important to make the habitats maintain such properties of wetland.

• Journal of agriculture & life science
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• v.46 no.4
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• pp.69-84
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• 2012

To provide the basic information on the excavation, conservation, and systematic management plan for preservation of valuable forested wetlands, a field survey was analyzed at public and private forests in Daegu city, 2010. The expected points of FGIS were identified, and buffer zones for the protection of forested wetlands were derived. According to the results from the 11 points of forested wetland, the flora of wetlands in Daegu city were consisted of a total of 169 taxa; 63 families, 131 genera, 148 species, 2 subspecies, 14 varieties, and 5 forms. The species diversity of shrubs in forest wetlands was highest at 1.560, and the evenness was highest in shrub trees at 0.913. Considering the type of wetland, topography, etc., the buffer zone was set at 20~50m from the core area boundary.

• Journal of English Language & Literature
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• v.57 no.2
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• pp.237-264
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• 2011

Based on its geophysical feature, the island has long been recognized as a separate and self-sustaining space independent of neighboring continent or other islands. Literary tradition has used the island as a metaphor for a utopian alternative to mundane human society with its various kinds of wrongdoings. Recent nature writings have taken up this island metaphor to emphasize the wholeness of the ecosystem in specifically designated natural community or landscapes such as national parks or wilderness preservation areas. Human-nature relations as border-divided area is also recognized as the island. Modern island biogeography, however, has disproved such a concept of islands as autonomous, revealing the contrasting fact that the richness of species on an undisturbed island is determined largely by species immigration from and emigration to a source of colonists. This scientific finding has posited the island as the interconnected nature, but the public and metaphoric use of it still resorts to the old concept of it as isolated and autonomous nature, because this image has been ingrained deeply in our consciousness and culture. Considering the negative consequences from the recognition of nature and nature-humans as isolated space, we need a new nature metaphor that embodies interconnectedness in nature and of human-nature relations. Such feature of interconnectedness is best embedded in the concept of ecotone. Some ecotones are created and maintained through human participation in nature, and this human induced nature of ecotone denotes the possibilities of a constructive relation between them. The substitution of the island with the ecotone as the concept of nature and the image of human-nature relations is expected to correct ecocritical practices of reading of nature writing, which has been predominantly interpreted within the orientation of nature itself and nature-human relations as an isolated and self-autonomous island. Adopting the ecotone in literary study enables ecocriticism to dig out cultural elements embedded in nature writing and reveal socio-political, ideological factors hidden behind the writers' portrayal of nature as islands.

• Economic and Environmental Geology
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• v.57 no.2
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• pp.143-159
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• 2024

Natural aggregate is an essential resource for human activities, closely related to construction. The aggregate demand has been increasing annually, and due to the nature of the resource, it is difficult to procure from distant locations. This study identifies the distribution and characteristics of aggregate-bearing areas as part of a municipal-level aggregate resource survey conducted in Nonsan City, Korea, in 2023. Nonsan City is located approximately 35 km straight distance from the Geum River estuary and lies at the passageway of the main stream of the Geum River. The topography of Nonsan City features eastern mountainous areas and western plains, creating an east-high-west-low geomorphic setting, with 33 streams distributed across the city, including tributaries of the Geum River like Nonsan Stream, Noseong Stream, and Ganggyeong Stream. All streams originate from the highlands in the north and east, converge with Nonsan Stream, and then join the west bank of the main stream of the Geum River at the western boundary of Nonsan City. Drilling core results show shallow depths in the highlands to the north and east, deepening towards the west, reaching a maximum depth of 25 m near the main stream of the Geum River. The total reserve of land aggregates is calculated to be 246,789,000 m³, with a developable amount of 172,750,000 m³. The total reserve of river aggregates is 5,236,000 m³, with a developable amount of 3,765,000 m³. The distribution of aggregates varies according to the geomorphic, geologic, and development pattern of the river system. Reserves are scarce in mountainous areas but are abundant in regions with rivers and wide alluvial plains, although reserves appear at depths greater than 4m. The distribution of aggregate resources in Nonsan City is influenced by stream activities and sea level changes, with the tidal range of the Yellow Sea acting as an unfavorable condition for the preservation of aggregate resources.