• Journal of the Korean association of regional geographers
• /
• v.12 no.5
• /
• pp.595-613
• /
• 2006

In the debates of development gains, the general rule is that it results from actions other than those of the landowner, most notably of the public sector as in granting of permissions for the development of specific land uses and densities or through infrastructure investments, or of socio-economic forces due to a general capital accumulation in space. A huge academic literature has investigated the development gains capture that refers to the process by which a portion of or all land value increments attributed to the community effort are recouped by the public sector. Policy instruments for applying development gains capture are based on deepening land value taxation, financing infrastructure, controling land use. But one of the most basic for the efficient policy implementation is the accurate estimation of development gains. This paper estimates the development gains generated by the total 204 building land projects of Korea Land Corporation and Korea National Housing Corporation since 1995.

• Ecology and Resilient Infrastructure
• /
• v.2 no.4
• /
• pp.345-350
• /
• 2015

The toxicity of red mud (RM) pellets for water purification was evaluated using Pseudokirchneriella subcapitata and Daphnia magna in a lab-scale experiment. According to the algal growth inhibition test, both specific growth rates and relative growth rates of P. subcapitata decreased, and the growth inhibition rates increased ($R^2=0.97$, p<0.001) as the concentration of RM pellets in the aqueous solution increased (>1.6 g/L). Also, based on the acute toxicity evaluation test on D. magna, toxic unit (TU) values ranged between 0.00 and 2.83, and increased with an increase in the concentration of RM pellets in the aqueous solution. A correlation analysis indicated that the pH of RM pellets was statistically correlated with TU values ($R^2=0.77$, p=0.02). The environmental implication from this study is that the concentration of RM pellets in an aqueous solution needs to be lower than 4.4 g/L to keep the maximum permissible TU value less than 1.0.

• Ecology and Resilient Infrastructure
• /
• v.5 no.3
• /
• pp.174-179
• /
• 2018

$TiO_2$-embedded expanded polystyrene (TiEPS) balls with powdered $TiO_2$ particles embedded on the surface of EPS were developed, and the growth inhibition of Chlorella ellipsoidea, a green algae, was evaluated. The experiment was conducted using four reactors with various conditions of (A) natural sunlight, (B) natural sunlight + TiEPS balls, (C) dark, and (D) dark + TiEPS balls on the roof of the building during five days. Based on the analysis of cell number, cell morphology, concentrations of chlorophyll-a and phaeopigments, both surface reactions in heterogeneous photocatalysis and light shielding could inhibit the growth of C. ellipsoidea. The highly reactive hydroxyl radicals ($OH{\cdot}$) from TiEPS balls degraded the lipid cell membrane through the peroxidation reaction with the light shielding, eventually resulting in cell inactivation. Although dominant inhibitory effects on the growth of C. ellipsoidea were ambiguous, TiEPS balls were feasible to prevent and inhibit the excessive growth of algae in eutrophic water body.

• Ecology and Resilient Infrastructure
• /
• v.3 no.4
• /
• pp.215-220
• /
• 2016

A new immobilization technique of nanoscale $TiO_2$ powder to expanded polystyrene (EPS) balls with temperature-controlled melting method was developed, and the photocatalytic activity of $TiO_2$ powder-embedded EPS balls were evaluated using methylene blue (MB) solution under ultraviolet irradiation (${\lambda}=254nm$). Based on the scanning electron microscope (SEM) images and associated energy-dispersive X-ray spectroscopy (EDX) analysis, the components of the intact EPS balls were mainly carbon and oxygen, whereas those of $TiO_2$-immobilized EPS balls were carbon, oxygen, and titanium, indicating that relatively homogenous patches of $TiO_2$ and glycerin film were coated on the surface of EPS balls. Based on the comparison of degradation efficiencies of MB between intact and $TiO_2$-immobilized EPS balls under UVC illumination, the degradation efficiencies of MB can be significantly improved using $TiO_2$-immobilized EPS balls, and surface reactions in heterogeneous photocatalysis were more dominant than photo-induced radical reactions in aqueous solutions. Thus, $TiO_2$-immobilized EPS balls were found to be an effective photocatalyst for photodegradation of organic compounds in aqueous solutions without further processes (i.e., separation, recycling, and regeneration of $TiO_2$ powder). Further study is in progress to evaluate the feasibility for usage of buoyant $TiO_2$-immobilized EPS to inhibit the excessive growth of algae in rivers and lakes.

• Ecology and Resilient Infrastructure
• /
• v.6 no.4
• /
• pp.208-216
• /
• 2019

This study investigated design factors and removal efficiencies of a sheet flow channel as natural type water improvement techniques in the stream. The channel was designed considering the design factors, then constructed and monitored in the test bed of the Osan stream's floodplain. Water lever, velocity, discharge, T-P, T-N, and NO₃-N were monitored and the removal efficiencies and design formula were suggested. Overall efficiencies of T-P, T-N, and NO₃-N range 10 - 20%, and they show consistent relations with residence times. Minimum velocity requirement is also suggested from the relation of algae conditions and velocities. Relation formula of residence time and removal efficiency will be applicable in the design and operation process of a sheet flow channel.

• Ecology and Resilient Infrastructure
• /
• v.6 no.2
• /
• pp.120-127
• /
• 2019

Medium-scale levee experiments were performed to monitor the infiltration and failure of levee body by applying fiber optic temperature sensing. In this study, bio-polymer soil was spread in the levee slope to increase the strength and intensity. Therefore, the infiltration and failure by overflows were produced in a different way compared to general soil type of levees. This was also observed in the experiment data for temperature changes monitored by fiber-optic distributed temperature sensing system. Through the analysis of temperature changes at specific location by time, the location and initiation time for physical changes and infiltration in levee body could be identified based on temperature variation. In this experiment, the time of rapid changes in temperature was ahead in the inland slope rather than the forceland slope. It was corresponding to the levee failure sequence of first inland slope failure and then the forceland slope failure.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.3
• /
• pp.579-586
• /
• 2021

This study examines the application of big data and tasks of tourism based on the case of Jeju Special Self-Governing Province, which used big data for regional tourism policy. Through the use of big data, it is possible to understand rapidly changing tourism trends and trends in the tourism industry in a timely and detailed manner. and also could be used to elaborate existing tourism statistics. In addition, beyond the level of big data analysis to understand tourism phenomena, its scope has expanded to provide a platform for providing real-time customized services. This was made possible by the cooperative governance of industry, government, and academia for data building, analysis, infrastructure, and utilization. As a task, the limitation of budget dependence and institutional problems such as the infrastructure for building personal-level data for personalized services, which are the ultimate goal of smart tourism, and the Personal Information Protection Act remain. In addition, expertise and technical limitations for data analysis and data linkage remain.

• Geomechanics and Engineering
• /
• v.24 no.5
• /
• pp.431-441
• /
• 2021

Rock-socketed drilled shafts are widely used to transfer the heavy loads from the superstructure especially in mountainous area. Extensive research has been done on the behavior of rock-socketed drilled shafts under compressive load. However, little attention has been paid to uplift behavior of drilled shaft in rock, which govern the overall behavior of the foundation system. In this paper, a series of centrifuge tests have been performed to investigate the uplift response of rock-socketed drilled shafts. The pull-out tests of drilled shafts installed in layered rocks having various strengths were conducted. The load-displacement response, axial load distributions in the shaft and the unit skin friction distribution under pull-out loads were investigated. The effects of the strength of rock socket on the initial stiffness, ultimate capacity and mobilization of friction of the foundation, were also examined. The results indicated that characteristics of rock-socket has a significant influence on the uplift behavior of drilled shaft. Most of the applied uplift load were carried by socketed rock when the drilled shaft was installed in the sand over rock layer, whereas substantial load was carried by both upper and lower rock layers when the drilled shaft was completely socketed into layered rock. The pattern of mobilized shaft friction and point where the maximum unit shaft friction occurred were also found to be affected by the socket condition surrounding the drilled shaft.

• Journal of the Korean Geosynthetics Society
• /
• v.22 no.3
• /
• pp.105-117
• /
• 2023

The recent global energy supply crisis has led to increased uncertainty in international energy markets. These market changes lead to a rise in global energy prices and development is expanding to the extreme cold regions (Arctic Circle) where undeveloped energy resources are abundantly stored. Arctic Circle has a special business environment such as natural environment, laws, institutions and culture, research on location evaluation of development areas is necessary in advance. In this study, the spatial information of Alberta, Canada, where non-traditional energy resource development activities have recently been active, was collected and analyzed. In addition, an optimal location evaluation model for resource development was developed using construction environment spatial information data and the reliability is verified by comparing and analyzing the existing resource development areas.

• Ecology and Resilient Infrastructure
• /
• v.10 no.4
• /
• pp.193-200
• /
• 2023

Influx of exotic fishes is the problem of fish management. The reason why interest on river environment was increased. Recently, River project was conducted to consider environmental function on the ecosystem and Eco-Diversity. Therefore, farmlands structure along the river was removed such as vinyl greenhouse. Daejeo ecological park was built in 4 River project. Daejeo ecological park have significance habitat for migratory birds and eco-diversity. In spite of nature river improvement, ecological system in river will be break down by exotic fishes. This study was conducted to investigate analyze the fish faun and prevailing species occupancy in Daejeo ecological park. This data will be used to make the management plan of exotic fishes in ecological park around Daejeo ecological park.