• Journal of Korea Spatial Information System Society
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• v.12 no.1
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• pp.18-27
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• 2010

In u-GIS environment, GeoSensor environment requires that dynamic data captured from various sensors and static information in terms of features in 2D or 3D are fused together. GeoSensors, the core of this environment, are distributed over a wide area sporadically, and are collected in any size constantly. As a result, storage space could be exceeded because of restricted memory in DSMS. To solve this kind of problems, a lot of related studies are being researched actively. There are typically 3 different methods - Random Load Shedding, Semantic Load Shedding, and Sampling. Random Load Shedding chooses and deletes data in random. Semantic Load Shedding prioritizes data, then deletes it first which has lower priority. Sampling uses statistical operation, computes sampling rate, and sheds load. However, they are not high accuracy because traditional ones do not consider spatial characteristics. In this paper 'Pre-Filtering based Post Load Shedding' are suggested to improve the accuracy of spatial query and to restrict load shedding in DSMS. This method, at first, limits unnecessarily increased loads in stream queue with 'Pre-Filtering'. And then, it processes 'Post-Load Shedding', considering data and spatial status to guarantee the accuracy of result. The suggested method effectively reduces the number of the performance of load shedding, and improves the accuracy of spatial query.

• Journal of the Korean Regional Science Association
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• v.32 no.2
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• pp.45-59
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• 2016

The purpose of this study is to analyze the static and dynamic change of wage differentials of women with disabilities in the Seoul local labor market. This study attempts to explain the double discrimination mechanism for disabled women and empirically gender discrimination and disability discrimination for them by using Oaxaca-Blinder decomposition analysis. In addition, using Juhn-Murphy-Pierce decomposition analysis. we analyze the wage differentials caused by the changed characteristics of disabled women and structures of discrimination at the Seoul local labor market. Data from the Panel Survey of Employment for the Disabled and Korean Labor and Income Panel Study for two years (2008, 2012) are used. According to the result, wage differentials of disabled women caused by disability discrimination is approximately 55% of total wage discrimination, whereas 45% is caused by gender discrimination during the period. Both observed and unobserved components move in the same direction to narrow wage differentials due to the disability discrimination and gender discrimination. Also the endowments in the Seoul local labor market about the changes of observed and unobserved components contribute more to narrow gender wage differentials, while these endowments widen disability wage differentials.

• Journal of the Economic Geographical Society of Korea
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• v.20 no.2
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• pp.189-213
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• 2017

This study seeks to critically examine the significance and limits of the cluster adaptive cycle model for analysis of cluster evolution and to propose research issues for future analysis of cluster evolution based on this critical examination. Until the 1980s, research on industrial complexes including clusters was based on a 'static perspective' that focuses on the aspect of economic space at a specific point in time, but the research paradigm has recently shifted to a 'dynamic perspective' focusing on 'evolution' of 'complex adaptive systems'. As a result, the adaptive cycle model has attracted attention as an analysis tool of dynamically evolving clusters. However, the cluster adaptive cycle model has emerged by being appropriately modified and expanded according to the properties of the cluster and its evolution. The cluster adaptive cycle model is a comprehensive analysis framework that identifies the characteristics of cluster evolution in terms of resource accumulation, interdependence, and resilience and classifies cluster evolution paths into six different categories. Nevertheless, there is still a need for further discussion and supplementation in terms of theoretical and empirical research to expand and deepen the model. Therefore, research issues for future analysis of cluster evolution are to specify and elaborate the cluster evolution model, to emphasize the concept of resilience, and to verify the applicability and usefulness of the model through empirical research.

• Journal of the Korean Society for Railway
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• v.18 no.3
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• pp.252-260
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• 2015

Ballasted track on an asphalt roadbed can be beneficial for its various effects such as (i) decreasing of roadbed thickness by dispersing train load; (ii) prevention of both strength reduction and weakening in roadbed system by preventing rainwater penetration; and (iii) reducing maintenance cost by preventing roadbed mud-pumping and frostbite. With these beneficial effects, ballasted track on asphalt roadbed has been widely used in Europe and Japan, and relevant research for applying such ballasted track on asphalt roadbed systems in Korea is ongoing. In this study, full-scale static and dynamic train load tests were performed to compare the performance of ballasted track on asphalt roadbed and ballasted track. The optimum thickness levels of asphalt and reinforced roadbeds, corresponding to the design criteria for reinforced roadbed of high-speed railway, was estimated using the FEM program ABAQUS. Test results show that the earth pressure on reinforced roadbed of ballasted track on the asphalt roadbed was relatively low compared with that of simple ballasted track. The elastic and plastic displacements of simple ballasted track on the asphalt roadbed were also lower than those of ballasted track. These test results may indicate that the use of ballasted track on asphalt roadbed is an advantageous system in view of long-term maintenance.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.6
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• pp.120-136
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• 2016

This study, views the color of scenery not as a static state, but rather as a continuous sequence of perceptions that incorporates the concept of time. This study derived techniques to quantitatively analyze the flow and data from this sequence. By utilizing this, urban color trends can be based on openness. This is very close to what would be experienced by an actual viewer: it extracted color data and visual amount from frames at 2-second intervals by shooting a video of the color sequence of the city as seen from both the left and right sides from the inside of the monorail (line 3 of the Daegu urban railway). These images were classified by color group, brightness, chroma, high chroma distribution derived techniques such as openness of space, brightness level, clarity level, high-chroma distribution and code, advantage of visual amount, dominant factor exposure, hot and cold color image and dynamic of sequence rhythm. During the derived sequence, the data determines the openness in the visual amount of sky and it was found that the tendency of the colors of the city was opening regression analysis. The more colorful the city is opening the brightness is lowered, the chroma increased slightly, cold colors significantly increased, which also had a very deep relationship with Lynch enclosed proportion, color change of the city trends through the actual scenery could grasp in more detail.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.2
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• pp.125-132
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• 2019

This paper presents a seismic reliability analysis method for an offshore wind turbine with a twisted tripod support structure under earthquake loading. A three dimensional dynamic finite element model is proposed to consider the nonlinearity of the ground-pile interactions and the geometrical characteristics of the twisted tripod support structure where out-of-plane displacement occurs even under in-plane lateral loadings. For the evaluation of seismic reliability, the failure probability was calculated for the maximum horizontal displacement of the pile head, which is calculated from time history analysis using artificial earthquakes for the design return periods. The application of the subset simulation method using the Markov Chain Monte Carlo(MCMC) sampling is proposed for efficient reliability analysis considering the limit state equation evaluation by the nonlinear time history analysis. The proposed method can be applied to the reliability evaluation and design criteria development of the offshore wind turbine with twisted tripod support structure in which two dimensional models and static analysis can not produce accurate results.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.1
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• pp.112-125
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• 2021

Marine spatial planning(MSP) designates the marine as nine kinds of use zones for the systematic and rational management of marine spaces. One of them is the fishery protection zone, which is necessary for the sustainable production of fishery products, including the protection and fosterage of fishing activities. This study intends to quantitatively identify the fishing activity space, one of the elements necessary for the designation of fisheries protection zones, by mapping of fishery activities using V-Pass data and deriving the fishery activity concentrated zone. To this end, pre-processing of V-Pass data was performed, such as constructing a dataset that combines static and dynamic information, calculating the speed of fishing vessels, extracting fishing activity points, and removing data in non-fishing activity zone. Finally, using the selected V-Pass point data, a fishery activity map was made by kernel density estimation, and the concentrated space of fishery activity was analyzed. In addition, it was confirmed that there is a difference in the spatial distribution of fishing activities according to the type of fishing vessel and the season. The pre-processing technique of large volume V-Pass data and the mapping method of fishing activities performed through this study are expected to contribute to the study of spatial characteristics evaluation of fishing activities in the future.

• Journal of The Korean Association For Science Education
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• v.29 no.4
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• pp.423-436
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• 2009

This study aims to develop an analytic framework that can be used to classify scientific models in science textbooks according to modes and attributes of representation and to investigate types of scientific models presented in the biology section of science textbooks for the $7^{th}$ to $10^{th}$ grades. The results showed that modes of representation of scientific models are related to the nature of sub-areas of biology sections. Generally, the iconic model and symbolic model were in dominant use, including drawings of organs and explanations of working of systems. However, the chapters on 'The Organization of Life' and 'The Continuity of Life' showed a relatively high frequency in use of the actual model. The theoretical model was presented in a part of 'The Continuity of Life', due to its highly abstract characteristics. Moreover, the gestural model and analogical model showed very low frequency. From the perspective of attributes of representation, frequency of the static model was very high, while one of the dynamic models was very low. Therefore, efforts to recognize the properties of scientific concepts more clearly and to develop diverse types of models that can represent the concepts adequately are required. Analysis of these types of scientific models can offer recognition of the usefulness and limitations of models in representing the concepts or phenomena, and can help us to design adequate models depicting particular properties of given concepts. Also, this type of analysis may motivate researchers to strive to reveal correct methods for and limits of using the scientific models that are presented in existing science textbooks, as well as to provide useful information to organize the science textbooks according to the revised $7^{th}$ national science curriculum.

• The Journal of the Petrological Society of Korea
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• v.19 no.3
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• pp.227-244
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• 2010

Abundant spinel lherzolite xenoliths showing distinctively different textural types such as protogranular, porphyroclastic, and mylonitic texture are trapped in the basaltic rocks from southeastern part of Jeju Island. These xenoliths show the textural spectrum from coarse-grained protogranular through porphyroclastic with bimodal grain size to fine-grained and foliated mylonitic texture. They tend to decrease in grain sizes and show more linear grain boundaries and more frequent triple junctions from protogranular through porphyroclastic to mylonitic. Spinel has different occurrence mode according the textural type. Spinel is always associated with orthopyroxene in protogranular texture, whereas it is scattered and independent of orthopyroxene in mylonitic texture. Additionally, porphyroblast from porphyroclastic and mylonitic textures has internal deformation features such as kink band, undulatory extinction and curved lamella, whereas neoblast is strain-free. These textural features indicate increasing degree of static/dynamic recrystallization from protogranular through porphyroclastic to mylonitic texture. The mg#[$=100{\times}Mg/(Mg+Fe_t)$] of olivine, orthopyroxene and clinopyroxene is relatively constant (ol: 88-91; opx: 89-92; cpx: 89-92) regardless of textural differences. The mg# of constituent minerals, NiO content (0.3~0.4 wt%) and MnO content (0.1~0.2 wt%) of olivine are similar to those of mantle xenoliths worldwide, also indicating that studied spinel lherzolite xenoliths were mantle residues having experienced 20~25% partial melting. The geochemical and textural characteristics have close relations showing that LREE and incompatible trace elements content of orthopyroxene and clinopyroxene increases from protogranular through porphyroclastic to mylonitic. These observations suggest that the studied mantle xenoliths experienced metasomatism by LREE enriched melt or fluid after partial melting, indicating a close relation between deformation and metasomatism. The metasomatism was possibly confined to narrow shear zones from where porphyroclastic and mylonitic textured xenoliths originated. These shear zones might favorably drive the percolation of LREE-enriched melts/fluids responsible for the metasomatism in the lithospheric mantle below the Jeju Island.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.3
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• pp.43-52
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• 1984

This paper is concerned with the strain characteristics of the time effect on the remoulded saturated day sampled from the downstream of the Yeongsan river, and the constitutive equation that can generally explain time-dependent behaviors of norma1ly consolidated clay. This paper examines whether or not the afore-said constitutive equation can be applied to the remoulded Mooan-clay. Throughout this study, the conclusions obtained are as follows. 1. Throughout the isotropic consolidation test for 7 days and the isotropic relaxation test, the existence of the static and dynamic yielding surfaces is confirmed respectively. 2. The characteristics of time effect of the deformation, namely, the existence of a unique stress-strain-time relation, is conformed from the experimental result on the Mooan-clay. 3. The prodictions of the stress path and the strain on the Cam-clay theory is not consistent with those observed during the experiments. 4. Constitutive equation(2-3-12) obtained by applying Cam-clay theory to Perzyna's elastic-viscoplasticity theory can explain the behavior of pore water pressure during isotropic stress relaxation, concerned with time dependency under undrained condition. The equation can also explain the results of the undrained triaxial compression test for the clay with different strain rate under the same or different consolidation history. 5. This constitutive equation has eight material parameters which can be determined from triaxial compression tests.