• Journal of the Korean Regional Science Association
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• v.37 no.4
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• pp.75-93
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• 2021

By defining a travel disparity based on the degree to which travelers diversify their destinations, this paper examines how socioeconomic and spatial factors affect the travel disparity among the elderly in Seoul. This paper uses the COVID-19 pandemic as a natural experiment which can bring about different behavioral responses among the older travelers. Using the smart card data, we compare the destination diversification patterns before and after the pandemic. In the early morning(4:30-9:00), the degree of destination diversification varies between the core and the periphery and this trend persists through the pandemic. In the late morning(9:00-12:00), a new trend of disparity appeared after the pandemic. Although those who hold higher socioeconomic status and live closer to the core have a larger range of choices for destinations, the difference of range did not lead to differences in diversification before the pandemic, due to the discretionary nature of the elderly's trip. In contrast, as the elderly were forced to search alternative destinations right after the outbreak of the pandemic, the range of choices became an important factor causing observable differences in destination diversification. The findings suggest that the travel disparity observed during the pandemic is due to the difference in the range of choices by socioeconomic and spatial factors.

• Land and Housing Review
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• v.14 no.3
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• pp.17-36
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• 2023

This research aims to investigate the socio-demographic, financial, and housing statuses of young married couples in Chonsei housing and to analyze the determinants of their residential environment quality and housing expenditure in four districts - Seoul and Gyeonggi-Incheon Area(GIA) of the Seoul Metropolitan Area(SMA), and metropolises and non-metropolises of non-SMA. From the 2020 Korean Housing Survey(KHS), this cross-sectional analysis examined a sample of 691 households, and the findings revealed that most were headed by college-educated, salaried male workers aged 31 years old. While childless dual-earner couples were common in Seoul, single-income families of three were prevalent in non-SMA. The financial status of the couples in Seoul was a lot better than in the other three areas, particularly much higher in Chonsei deposit and total asset value. Further, many lived in a three-bedroom apartment unit sized 60m² and bigger, using a Chonsei loan. Regardless of areas, almost all the households spent a very low portion of their living expenses and income on housing costs. However, dual-earner families positively increased borrowing capacity, which improves the household's financial position that is likely to lead to equity increment in a volatile asset market in the long run. The statistical results indicated that residential environment assessment was influenced by neighborhood quality and housing expenditure was affected by housing size in Seoul, urban amenities in GIA and householder's gender in non-metropolises. Thus, this research proposes that strong measures be considered to mitigate housing inequality embedded in geographical and socio-economic disparities.

• Land and Housing Review
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• v.15 no.3
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• pp.1-23
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• 2024

In the face of an impending demographic cliff, this research delves into geographical disparities in socioeconomic statuses and living arrangements of young single women in rental housing and also to explore influential factors of their residential assessment and housing expenditure. From the Korean Housing Survey of 2020, the cross-sectional study identified 847 unmarried female single-person householders aged between 20 and 39 in four districts - Seoul and Gyeonggi-Incheon Area (GIA) of Seoul Metropolitan Area (SMA), and metropolises and non-metropolises of non-SMA. The empirical analyses revealed that regardless of regions, most of the respondents were college-educated, salaried employees in late 20s living in a studio flat, seldom bore debt and barely relied on social services. Renters in SMA, employment rate, income and living expenses were higher than those in non-SMA and they resided in small, old but adequate housing with a separate bedroom. In particular, Seoulites suffered from housing cost overburden but most singles in GIA benefited from the lowest housing burden. While the main determinant of residential assessment was livability, housing satisfaction was additionally affected by old housing and the satisfaction with residential environment was also explained by urban amenities. Despite geographical variations, housing expenditure was primarily driven by income and employment.

• Journal of the Korean Applied Science and Technology
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• v.34 no.2
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• pp.400-409
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• 2017

The purpose of this study was to measure the antioxidant and physiological activities of seed from Gardenia jasminoides Ellis fructus (GJE) in Namhae Korea. We determined proanthocyanidin. GJE seed were extracted by 70% ethanol, chloroform:methanol, 2:1 volume ratio (CM) and n-butanol of three solvents. To investigate by the solvent extract of flavonoid content and value as a functional food ingredient of GJE seed through various antioxidant activities were performed. Solvent extract antioxidant activity of increasing concentrations (0.2, 0.4, 0.6 mg/mL) were significantly increased (p<0.05). The content of proanthocyanidin in GJE seed was $70.035{\pm}0.772mg$ catechin eqivalents/g dry weight. As a result of bioactivity assay, by a solvent of seed were found that the relationship with the increase of flavonoid content increased bioactivities. The antioxidant activity of the extract from the other except for the n-butanol extract on seed was observed at a high level. The results suggest that Gardenia jasminoides Ellis fructus seed can be used as a natural antioxidant.

• Journal of Conservation Science
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• v.22
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• pp.31-42
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• 2008

A stone cultural heritage often lacks design drawing and detailed geometric informations, thus it becomes more difficult to conservation and restoration. Even though there is active database of detail shape information and numerical measurement for stone monuments, most of the data is in hard-to-utilize two-dimensional images. The new technology developed to overcome this problem is three-dimensional image scanning system. The multi-storied stone pagoda of the Daewonsa temple was analysed with 3D scanning image data then survey map with orientation displacement was evaluated. The difference of each side became apparent with the members of the stone properties was measured, also horizontal and vertical displacement occurred. Horizontal displacement occurred in increasing severity from left to right and from body section to upper part. The 8th roof stones are leaning toward northwest direction due to lateral displacement. The evaluation and measurement of displacement could cause a little errors due to the characteristics uneven surface of stone monuments, computer program and mistakes from the researcher. In future, more precise measurement and stability studies should be done to suggest that accurate data for conservation and understanding of damage condition can be provided.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.135-139
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• 2007

Recently Data Centric Storage (DCS) schemes are variously studied for several applications (e.g. natural environment investigation, military application systems and environmental changes monitoring). In DCS scheme, data is stored at nodes within the network by name. There are several drawbacks in the existing schemes. The first is the inefficiency of the range query processing on not considered the locality of store point. the second is the non-homogeneity of store load of each sensors in case of the sensor distribution density is non-uniformed. In this paper, we propose a novel data centric storage scheme with the sensor distribution density which satisfied with the locality of data store location. This scheme divides whole sensor network area using grid and distributes the density bit map witch consist of the sensor density information of each cell. sensors use the density bit map for storing and searching the data. We evaluate our scheme with existing schemes. As a result, we show improved load balancing and more efficient range query processing than existing schemes in environment which sensors are distributed non-uniform.

• Journal of the Economic Geographical Society of Korea
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• v.9 no.3
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• pp.318-340
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• 2006

In the last decade, there has been a widespread interest in knowledge production activities as a new engine of endogeneous growth. In the knowledge-based economy, there has been a growing importance of the patent as the index of knowledge production. Much literature suggests that knowledge production activities tend to be spatially concentrated and formed the clusters in the advanced economies. The purpose of this paper is to analyze spatial-temporal patterns of knowledge production activities in Korea based on a data set of patents from 1981-2000. This paper uses spatial statistical methods and GIS to explore the spatial dimensions of knowledge production activities in Korea. Through this research, it was found that knowledge production activities were unevenly distributed. The knowledge production activity measured by patent counts is highly concentrated in a limited number of cities. The top 10 cities accounted for 68.5% of the total number of patents in the period of 1981-2000, suggesting the existence of a strong concentration of knowledge production activities in Korea. The locations of knowledge production activities by themselves represented a strong spatial autocorrelation. The concentration of knowledge production activities in Korea is spatially correlated to the concentration of adjacent neighboring cities. The location of knowledge production activities is not free from a spatial context and spillover of knowledge production activities are heavily bounded within geographic limits, forming a spatial cluster. There appear some quite a large spatial cluster around the seoul metropolitan area.

• Korean Journal of Plant Taxonomy
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• v.43 no.2
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• pp.118-127
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• 2013

A comparative study of leaf epidermal microstructure in tribes Forsythieae (Abeliophyllum: 1 species, Forsythia: 12 taxa - 10 species, 2 varieties), Fontanesieae (Fontanesia: 2 species) including one related genus Myxopyrum belonging to Myxopyreae (Myxopyrum: 5 taxa - 4 species, 1 subspecies) was carried out using scanning electron microscopy (SEM) in order to evaluate their significance in the taxonomy. The leaves of investigated taxa are either hypostomatic or amphistomatic, but former is more frequent. The size range of the guard cells is 17.14-47.58 ${\times}$ 11.59- 44.25 ${\mu}m$: the smallest one was found in Forsythia giraldiana (17.48-22.96 ${\times}$ 11.64-12.88 ${\mu}m$), while the largest one was measured to Myxopyrum pierrei (31.50-41.75 ${\times}$ 32.53-44.25 ${\mu}m$). Anomocytic stomatal complex are most frequent type (rarely paracytic), usually both anomocytic and anisocytic occur in one leaf. In surface view both adaxial and abaxial anticlinal walls of the subsidiary cells are variable (e.g., straight/curved, undulate, sinuate, undulate/sinuate). Three types (simple unicellular and multicellular non-glandular, subsessile glandular) of trichomes are found in leaves. Finally, the systematic significance of the leaf epidermal micromorphological characters in idenfitication and elucidation of these tribe, between or within the genera including among the species is also briefly discussed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.4 s.74
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• pp.429-440
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• 2006

This paper comprises two specific objectives. The first is to examine the applicability of ordinary kriging interpolation(OK) to the p-adaptivity of the finite element method that is based on variogram modeling. The second objective Is to present the adaptive procedure by the hierarchical p-refinement in conjunction with a posteriori error estimator using the modified S.P.R. (superconvergent patch recovery) method. The ordinary kriging method that is one of weighted interpolation techniques is applied to obtain the estimated exact solution from the stress data at the Gauss points. The weight factor is determined by experimental and theoretical variograms for interpolation of stress data apart from the conventional interpolation methods that use an equal weight factor. In the p-refinement, the analytical domain has to be refined automatically to obtain an acceptable level of accuracy by increasing the p-level non-uniformly or selectively. To verify the performance of the modified S.P.R. method, the new error estimator based on limit value has been proposed. The validity of the proposed approach has been tested with the help of some benchmark problems of linear elastic fracture mechanics such as a centrally cracked panel, a single edged crack, and a double edged crack.

• Journal of the Korea Society of Computer and Information
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• v.18 no.6
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• pp.29-36
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• 2013

In wireless sensor networks, energy is the most important consideration because the lifetime of the sensor node is limited by battery. Most of the existing energy efficient routing protocols use the minimum energy path to minimize energy consumption, which causes an unbalanced distribution of residual energy among nodes. As a result, the power of nodes on energy efficient paths is quickly depletes resulting in inactive. To solve these problems, a method to equalize the energy consumption of the nodes has been proposed, but do not consider the link error rate in the wireless environment. In this paper, we propose a uniform energy consumption of cluster-based multi-hop routing mechanism considering the residual energy and the link error rate. This mechanism reduces energy consumption caused by unnecessary retransmissions and distributes traffic evenly over the network because considering the link error rate. The simulation results compared to other mechanisms, the proposed mechanism is energy-efficient by reducing the number of retransmissions and activation time of all nodes involved in the network has been extended by using the energy balanced path.