• Journal of the Economic Geographical Society of Korea
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• v.1 no.1
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• pp.137-149
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• 1998

It is likely that the spatial structure of the intraurban accessibility as well as the accessibility value of each of the nodes in the subway network is affected by the addition of new linkages. The changes in the accessibility at individual nodes also affect the accessibility in the surrounding areas at some distances away from the nodes. Graph-theoretic algorithms have been developed as a proper measurement scheme for the nodal accessibility in tracked transport networks such as subway networks. However, the graph-theoretic measurements have limitations to estimate the spatial diffusion effect on the surrounding areas. This study proposes a new model for the spatial diffusion effect estimation of nodal accessibility increment in the subway network toward the surrounding areas. Since the distance decay trend of subway station use reflect the spatial diffusion effect of the accessibility of subway station toward the surrounding area. The model is deduced from the subway station use density function which is formulated by the questionnaire survey data.

• Journal of the Economic Geographical Society of Korea
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• v.17 no.3
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• pp.482-501
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• 2014

Most textbooks of urban geography explain that land value drops down with distance from the Peak Land Value Intersection of urban center. However, There is little rigorous empirical work supporting this belief. Using the publicly notified individual land price data of 2013, this paper examines the structure of land value in urban center with a focus on spatial distribution of land value by land use. As an analytic result, the structure of land price varies between land uses, significantly being different from the classical model of land value in urban space. In residential lands and mixed-use lands for residence and commerce, land price gradient as a function of distance from PLVI is positive and a crater phenomenon even is identified in spatial distribution of land value. The classical model coincides only with land for commerce and office. Nonetheless, predict of land uses by land value function fairly corresponds to Alonso's model.

• International Commerce and Information Review
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• v.14 no.2
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• pp.349-367
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• 2012

Recently, the global paradigm on the economic structure has been changed from the price-oriented borderless competition toward the sustainable quality movement due to the ever-increasing global warming and environmental issues. Since Korea hosted the global 20 summit in 2010, it has promoted the green growth policies and asked for the other countries to participate in. Unfortunately, it is not easy to figure out the green growth or green productivity because the economic performance has a side effect of environmental pollution such as CO2 emission. This paper aims to analyzes the methodological comparison for all the related issues with green productivity and suggests the new paradigm of global Malmquist-Lundberger index (GML) as the most flexible field and performance-oriented criteria to measure the green productivity.

• Economic and Environmental Geology
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• v.18 no.2
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• pp.151-157
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• 1985

Events detected by the KIER microearthquake network operated in the Southern Part of Korea for 265 days in 1982~1984 were reviewed, and some of them were identified to be a dynamite explosion from several construction sites. The purpose of the present work is to determine the crustal structure of the Southern Korea using the time-destance data obtained from such explosion seismic records. The time·distance data can be well explained by a crustal model composed of four horizontal layers of which thickness, p and s-wave velocity ($V_p$ and $V_s$) are characterized as follows. 1st layer (surface) ; 0~2km, $V_p=5.5km/sec$, $V_s=3.3km/sec$ 2nd layer (upper crust) ; 2~15km, $V_p=6.0km/sec$, $V_s=3.5km/sec$ 3rd layer (lower crust) ; 15~29km, $V_p=6.6km/sec$, $V_s=3.7km/sec$ 4th layer (upper mantle) ; 29km~ , $V_p=7.7km/sec$, $V_s=4.3km/sec$ The relatively shallow crust·mantle boundary and low $P_n$ velocity compared with the mean values for stable intraplate region are noteworthy. Supposedely, it is responsible for the high heat flow in the South-eastern Korea or an anomalous subterranean mantle. The mean $V_p/V_s$ ratio calculated from the relation between p-wave arrival and s-p arrival times appears to be 1.735 which is nearly equivalent to the elastic medium of ${\lambda}={\mu}$. However, the ratio tends to be slightly larger with the depth. The ratio is rather high compared with that of the adjacent Japanese Island, and the fact suggests that the underlying crust and upper mantle in this region are more ductile and hence the earthquake occurrences are apt to be interrupted. As an alternative curstal model, a seismic velocity structure in which velocities are successively increased with the depth is also proposed by the inversion of the time·distance data. With the velocity profile, it is possible to calculate a travel time table which is appropriate to determine the earthquake parameters for the local events.

• Economic and Environmental Geology
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• v.54 no.5
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• pp.495-503
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• 2021

Aggregate is a major natural resource used in SOC construction, such as housing, roads, ports, etc., and is a fundamental material for national construction. Although aggregates account for only about 4% of the construction cost, aggregates occupy about 80% of the construction volume and are essential factors that determine the quantity and quality of buildings. For river, underwater, riverbed, sea, and land aggregates, it is difficult to rapidly increase the production of aggregates when there is difficulty in supply and demand due to environmental problems and limited resources during production, whereas forest aggregates are relatively easy to increase production. Forest aggregates are considered promising as alternative aggregate resources in the future when reducing other aggregates due to their abundance of natural resources, and are an effective aggregate source that can flexibly respond to aggregate demand in accordance with well-organized plans and policies. This study proposed the plan for activating the development of forest aggregates in the case of long and short transport distances, which is a factor that has a great influence on the development, and measures for the current difficulties in forest aggregate development

• International Journal of Computer Science & Network Security
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• v.22 no.4
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• pp.209-216
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• 2022

The modern development of higher education in Ukraine is the result of two main factors. One of them - the factor of social progress - reflects the transformations inherent in modern Ukrainian society. These include, first of all, the processes of democratization and the development of civic responsibility. European the choice of Ukraine, the integration of our state into the European space determine accordingly, the second factor influencing the development of domestic higher education - the trends that guide the progress of the European Higher Education Area (European Higher Education Area (hereinafter - EHEA) and the European Research Area Research Area, hereinafter - ERA). The strategy of information support of the educational process (approved by the European Commission in 2010) recognizes the leading role of higher education as a driver of social progress, accordingly states the priority - the development of free economic education and identifies indicators of such progress - the achievement and international attractiveness of European free economic education. The information support of modernization challenges in higher education are aimed at the educational process, the leadership position of students, in particular through promotion and implementation of leading achievements and best practices in the context of globalization.

• Economic and Environmental Geology
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• v.57 no.2
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• pp.219-231
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• 2024

A survey of concrete plants in Incheon Metropolitan City and Gyeonggi Province was used to conduct an analysis of aggregate transport distance and production forms, as well as to evaluate the features and current status of aggregates distribution. As a result, areas such as Incheon, Siheung, Bucheon, Gimpo, and Siheung, where the distance to the demand points is less than 20 km, exhibited bidirectional distribution whereas Paju, Yongin, Yangju, and Pocheon, with distances ranging from 20 to 50 km is showed a unidirectional distribution pattern supplying aggregates exclusively to Incheon. Survey on manufacturing forms, more than 85% of the gravel dispersed in the Incheon area is made up of crushed aggregates derived from rocks discharged at construction sites indicating a considerable skew in supply chain. These findings are predicted to have a detrimental influence on aggregate supply in the long run, necessitating policy changes targeted at building an optimal aggregate distribution market.

• Journal of Korea Port Economic Association
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• v.40 no.1
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• pp.119-131
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• 2024

This study examines the interrelationship between coastal passenger demand and fares for 101 coastal passenger routes in Korea during the 2018 to 2022 period. The two-stage least squares method through a panel data simultaneous equations model was estimated to the effects of individual route characteristics and regional characteristics on the performance and fares of coastal passenger transportation. The estimated results indicate that the endogenous variable, fare, and the exogenous variables, route characteristics, route distance, and the instrumental variable, frequency, affect the demand for coastal passengers. In the short-run pricing function, the exogenous variables, capacity, speed, and route distance, as well as the endogenous variable, coastal passenger transportation performance, affect the coastal passenger fare. This study is expected to provide useful implications for domestic coastal passenger demand and pricing in relation to coastal passengers.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.3
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• pp.214-220
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• 2014

The aim of this study is to optimize the efficiency of a photobiorector on the growth rate of Chlorella vulgaris (C. vulgaris) by varying distance of optical panel (OP). The round shaped C. vulgaris (FC-16) having the size of $3-8{\mu}m$ is employed in this study. The cells of C. vulgaris are cultured in the Jaworski's Medium with deionized water at $22^{\circ}C$ for 15 days. The OP is placed at four different distances i.e., at 225 mm distance (Run 1), 150 mm distance (Run 2), 112.5 mm distance (Run 3) and 90 mm distance (Run 4) having a LED (Light Emitting Diode) source. The diffuse rate is achieved to 86%, 90%, 92% and 94% for Run 1, Run 2 Run 3 and Run 4, respectively. A narrower distance of OP caused to effectively to increase the efficiency of diffuse light rate. For mass cultivation of this biomass, medium is changed according to distance of OP after attaining a maximum biomass concentration; Run 1 in 8 days, Run 2 in 6 days, Run 3 in 4 days and Run 4 in 3 days. In addition, the amount of maximum biomass rate for Run 4 was reached 3 times higher than that of Run1. However, growth rate, chlorophyll per cell, cell volume and doubling time are found to be Run 3 and Run 4 higher than that of Run 1 and Run 2 samples. However, Run 3 and Run 4 are having a slight difference in all these measurements. These findings suggest that in terms of economic consideration and efficiency towards simultaneous mass cultivation of biomass, Run 3 was found to be more effective than other samples.

• The Journal of the Korea Contents Association
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• v.19 no.4
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• pp.598-608
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• 2019

This study is empirically intended to look into the effects of safety income system on recipient's economic independence and life satisfaction under the social security system. To achieve this, a survey was carried out to 650 adult householders benefiting from the social security system. The SPSS 23 statistical program was used to apply measurement variables related to the safety income system. The results of this study are summarized as follows. The social insurance and the social assistance of safety income system were adopted, having a significant effect on the economic independence. The effect of economic independence on life satisfaction was rejected, while the effect of social assistance on life satisfaction was adopted, showing a difference in the effect of each factor. The findings imply that social insurance and social assistance with support for safe income can be a positive help for economic independence, and unemployment benefit, national pension, long-term care subsidy and health insurance can help to achieve real economic independence, adopting only social assistance with limitation to life satisfaction. Consequently, the safety income system is very useful in helping recipients to achieve their economic independence through its introduction, but there is some distance to meet their life satisfaction.