• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.187-196
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• 2005

Since the allowable bearing capacities of piles in weathered/fractured rock are mainly governed by settlement, the load-displacement behavior of pile should be known accurately. To predict pile head settlement at the design stage, the exact understanding of the load-transfer mechanisms is essential. Therefore, in this research, the load-transfer mechanism of drilled shaft socketed into weathered rock was investigated. For the investigation, five cast-in-place concrete piles with diameters of 1,000 mm were socketed into weathered gneiss. The static axial load tests and the load-transfer measurements were performed to examine the axial resistant behavior of the piles. A comprehensive field/laboratory testing program on weathered rock at the Held test sites was also performed to describe the in situ rock mass conditions quantitatively. And then, the effect of rock mass condition on the load transfer mechanism was investigated. The f-w (side shear resistance-displacement) curve of the pile in moderately weathered rock reached to yielding point at a for millimeter displacements, and after yielding point, the rate of resistance increment dramatically decreased. However, the f-w curve in the highly/completely weathered rock did not show the obvious yielding point, and the resistance gradually increased showing the hyperbolic pattern until relatively high displacement (>15 mm). The q-w (end bearing resistance-displacement) curves showed linear response at least until the base displacement of approximately 10 mm, regardless of rock mass conditions.

• Journal of Korean Society of Rural Planning
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• v.9 no.4 s.21
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• pp.35-41
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• 2003

The purpose of this study is on identifying the function of ground temperature arrangement of village grove. Case study was accomplished at Hacho village grove in Jinan-gun, Jeonbuk province. Hacho village grove was the largest grove of all and most formal grove in Jinan region. So ground temperature of outside and inside of Hacho village grove were measured from March to October in 2001. And comparative review about difference between outside and inside of village grove was accomplished. Our ancestors, in spite of orient and occident, have made a settlement in consideration of climatic conditions. We have to team from past pattern and add modern scientific technology. So traditional wisdom and wise planning process must be considered in order to create qualitative residential environment in present through natural elements. It is identified that in winter, the inner side ground temperature is higher than outside one of that and in summer, in contrary, the inner side one of that is lower than outside one of that. So it is identified that Macho village grove breaks winds and reduce the heating energy in winter, it reduces ground temperature and reduces cooling energy very well in summer. It is identified that village grove reduce ground temperature in summer better than any other season. It is identified that in summer, the effect of maintaining constant temperature is also better than my other season. So it is identified that village grove stabilize most changeable outside temperature in inside of that.

• Explosives and Blasting
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• v.38 no.4
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• pp.26-36
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• 2020

With the increase of expansion and use of the underground space, the possibility of an underground explosion by terrorists is increasing. In this study, after modeling a circular tunnel excavated at a depth of 50m, an explosion load was applied to the inside of the tunnel. As for the explosion load, the explosion load of the maximum explosive amount for six types of vehicle booms proposed by ATF (Bureau of Alcohol, Tobacco, and Firearms) was calculated. For the rock mass around the circular tunnel, three types of rock grades were selected according to the support pattern suggested in the domestic tunnel design. Nonlinear dynamic analysis was performed to evaluate the influence of the ground structure by examining the surface displacement using the explosion load and rock mass characteristics as parameters. As a result of the analysis, for grade 1 rock, the influence on the uplift of the surface should be considered, and for grade 2 and 3 rocks, the influence on a differential settlement should be considered. In particular, for grade 3 rocks, detailed analysis is required for ground-structure interaction within 40m. Also, it is considered that the influence of Young's modulus is the main factor for the surface displacement.

• Journal of the Korean association of regional geographers
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• v.22 no.4
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• pp.774-791
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• 2016

Recent studies on Asian suburbanization suggest that their settlement patterns do not confirm to those of earlier migrant streams, and that different residential patterns of Asian ethnic minority groups have created a complex ethnic mosaic in suburban areas. This paper examines the extent to which residential patterns of main Asian minority groups have changed in Westchester, where is one of suburban counties around New York City. With mapping base on Census of Population data in 2000 and 2010 years, the residential patterns of five Asian groups (Asian Indians, Chinese, Filipinos, Japanese, and Koreans) are analyzed through the indices of segregation. The residential segregation geography of the Asian ethnic groups is characterized by dispersed concentration. There is a difference among the characteristics of the ethnic neighborhoods in which Asian minority groups are residentially concentrated.

• Structural Engineering and Mechanics
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• v.41 no.6
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• pp.711-734
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• 2012

The foundation of a tall building frame resting on settable soil mass undergoes differential settlements which alter the forces in the structural members significantly. For tall buildings it is essential to consider seismic forces in analysis. The building frame, foundation and soil mass are considered to act as single integral compatible structural unit. The stress-strain characteristics of the supporting soil play a vital role in the interaction analysis. The resulting differential settlements of the soil mass are responsible for the redistribution of forces in the superstructure. In the present work, the nonlinear interaction analysis of a two-bay ten-storey plane building frame- layered soil system under seismic loading has been carried out using the coupled finite-infinite elements. The frame has been considered to act in linear elastic manner while the soil mass to act as nonlinear elastic manner. The subsoil in reality exists in layered formation and consists of various soil layers having different properties. Each individual soil layer in reality can be considered to behave in nonlinear manner. The nonlinear layered system as a whole will undergo differential settlements. Thus, it becomes essential to study the structural behaviour of a structure resting on such nonlinear composite layered soil system. The nonlinear constitutive hyperbolic soil model available in the literature is adopted to model the nonlinear behaviour of the soil mass. The structural behaviour of the interaction system is investigated as the shear forces and bending moments in superstructure get significantly altered due to differential settlements of the soil mass.

• Korean Journal of Labor Studies
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• v.24 no.3
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• pp.73-107
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• 2018

The purpose of this study is to shed light on the characteristics of the social relations of migrant workers in the Ansan area and the factors for the construction of those characteristics. The social relations of migrant workers in the Ansan area are affected by the Korean government's policy of EPS, a short-term rotation policy and its ban on the settlement of migrant workers. These workers are likely to form a temporary and bounded social relationship. The bounded social relationship of migrant workers to society is one of the major factors that put them in social poverty. Ethnic communities, support organizations for migrant workers, and local government agencies have assumed the task of helping build the network among migrant workers of various ethnic backgrounds as well as aiding their participation in local social activities. The status of a temporary resident is the prime reason for spatial exclusion and social poverty among migrant workers. To prevent the exacerbation of these phenomena, this study suggests that the government reconsider its short-term work permit policy for less skilled workers.

• Journal of the Korean Geotechnical Society
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• v.23 no.5
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• pp.89-100
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• 2007

In this study, various field and laboratory tests were performed to investigate the characteristics of shear strength and bearing behavior to be considered in the estimation of stability and trafficability in early stage of stabilization process in marine clay dredged deposit. Site characterization was carried out to grasp the basic properties of the deposit. Field vane test, unconfined compression test and direct shear test were conducted to evaluate the shear strength distribution for varied depths, and the characteristics of shear strength and stress-strain behavior of the crust layer. Plate load tests were also performed to estimate the bearing capacity and to assess load-settlement behavior and failure pattern of the deposit. The bearing capacity was also estimated using previously proposed methods for double-layered clay deposit. The estimated bearing capacity was compared with the results of the plate load tests and then, the applicability of the estimation method was discussed.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.4
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• pp.387-402
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• 2014

In congested urban areas, constructions of tunnel structures have became necessary due to a lack of surface space. The excavation of any tunnel generated the ground disturbances of surrounding ground and displacements is major concern. Therefore, a study of tunnel stability is necessary. In this study, the authors have investigated the stability and failure pattern of tunnel through the model tunnel test. In this study, the close range photogrammetry was used to measure the ground deformation. The measured data was converted to displacement vectors and contours. And then it compared to FE analysis and empirical formula. In addition, this study presented the comparison between steel pipe reinforced model tunnel and unreinforced model tunnel. The ground deformation for both the steel pipe reinforced model tunnel and the unreinforced model tunnel was analysed.

• Korean Journal of Environment and Ecology
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• v.31 no.6
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• pp.520-528
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• 2017

The exotic black soldier fly, Hermetia illucens, has been paid much attention as an excellent organic matter decomposer. We conducted the nationwide survey and the population genetic study using a mitochondrial cytochrome C oxidase 1 gene to understand its genetic diversity and distribution pattern in Korea. The results show that it has successfully settled down in South Korea and there are only 10 haplotypes and the populations of the insect are highly differentiated. The results may indicate that their dispersal was restrained probably due to their short distance flying tendency since their introduction and settlement of only few maternal lineages with certain genotypes in Korea.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.4
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• pp.45-71
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• 1991

The landscape systems in Korean island settlements can be recognized as results of ingabitants' ecological adptation to the isolated environment with the limited natural resources. Both the fishery dominant industry in island society and ecological nature of its environments seem to have influenced on inhabitants' environmental cognition as well as the physical landscape of island villages such as its location, spatial pattern in each village, housing form and so on. This study was done mainly by both refering to the related documents and direct observations in case study areas, and results of the study can be summarized as follows. 1. In general, the landscape of an individual island seems to take more innate characteristics of island's own, corresponding to the degree of isolation from mainland. That is, while the landscape of island in neighboring waters takes both inland-like and island-innate landscape character at the same time, the one in the open sea far from land takes more innate landscape character of all island's own in the aspects of village location, land use and housing density etc. 2. The convex landform of most islands brings about more centrifugal village allocation than centripetal allocation in most inland villages. And thus most villages in each island face extremely diverse directions different from the south facing preference in most inland rural villages. 3. Most island villages tend to be located along the ecologically transitional strip between land and sea, so called 'line of life', rather than between hilly slope and flat land as being in most inland village locations. So they are located with marine ecology bounded fishing ground ahead and land ecology bounded agricultural site at the back of them. 4. The settlement pattern of the island fishing villages shows more compact spatial structure than that of inland agricultural villages, due to the absolute limits of usable land resources and the adaptation to the marine environment with severe sea winds and waves or for the easy accessability to the fishing grounds. And also the managerial patterns of public owned sea weed catching ground, which take each family as the unit of usership rather than an individual, seem to make the villagescape more compact and the size of Individual residence smaller than that of inland agricultural village. 5. The folk shrine('Dand') systems, in persrective of villagescape, represent innate environmental cognition of island inhabitants above all other cultural landscape elements in the island. Usually the kinds and the meanings of island's communal shrine and its allocative patternsin island villagescape are composed of set with binary opposition, for example 'Upper shrine(representing 'earth', 'mountain' or 'fire')' and 'Lower Shrine(representing 'sea', 'dragon' or 'water') are those. They are usually located at contrary positions in villagescape each other. That is, they are located at 'the virtical center or visual terminus(Upper shrine at hillside behind the village)' and 'the border or entrance(Lower Shrine at seashore in front of the village)'. Each of these shirines' divinity coincides with each subsystem of island's natural eco-system(earth sphere vs marine sphere) and they also contribute to ecological conservation, bonded with the 'Sacred Forest(usually with another function of windbreak)' or 'Sacred Natural Fountain' nearby them, which are representatives of island's natural resources.