• Journal of the Korean association of regional geographers
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• v.9 no.4
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• pp.461-480
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• 2003

This paper is to consider the new urbanization process of Daegu in the 1990s, especially with its economy, politics, social culture, environment and space. In the economic aspect, the industrial structure of Daegu has shifted from the manufacturing- centered economy to the service economy. But it has not yet overcome the linear frame of industrial structure still relying on the textile industry, though the degree of industrial specialization has increased in the part of the fabricated metal products and the precision and optical instrument. In the political situation that the implementation of the local self-government has made the relation between localities more competitive, the local government of Daegu has led a boom for boosting the regional economic growth, organizing private-public-research relations to improve the weakening regional investment and production function. In the social and cultural aspect of the new urbanization, the investment into the soft-ware facilities has been increased, and the urban festivals have been changed so as to revitalize the regional economy. In the environmental aspect, as the self-government system has launched, conflicts around values and interests of local governments have revealed frequently due to locations of infra-structures and of abhorrence facilities. Finally, seen from the spatial dimension of the city, the extension of residential areas and unregulated use of urban space have a result of inefficience of land-use, and this kind of unplanned outer expansion of the city has brought about with further separation of house and working place, and increasing distance of movements and the an urban spatial structure which requires more energy consumption.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.500-504
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• 2008

The objective of this paper is to evaluate the feasibility of using an optimization model as a effective way to search conjunctive operation scheme to meet two conditions; one is to minimize the electric cost for pumping and another is to meet the water demand for satisfying customers. The feasibility is confirmed as comparing the best combinations of pumps between multi-regional water supply networks from multiple sources which are obtained through an optimization modeling and EPAnet modeling. KModsim model, a network optimization model, was used to determine conjunctive operation scheme in the pipe system. KModsim, based on Lagrangian Relaxation algorithm, is useful for modeling network system and obtaining simultaneously pump combination and water allocation with given input option such as energy unit cost supplying from a source into a consumer, operating pumping combination. This study develops the procedure of determining optimal conjunctive operation scheme with using KModsim model. As a study region, the water supplying systems of the Geojae-city in the Geongsang Namdo Province was selected and investigated. The EPAnet hydraulic simulation result(Ryu et al, 2007, KSWW) gave input data for optimization model; energy unit price(won/$m^3$), water service available area etc.. It was assured that the combination of pump operation through optimum conjunctive operation is to be optimum scheme to obtain the best economic water allocation with comparison to the hydraulic simulation result such as electric cost and pump combination cases. The results obtained through the study are as follows. First, It was found that a well-allocated water supply scheme, the best combination of pump operation through optimum joint operation, promises to save the electric cost and satisfy all operational goals such as stability and revenues during the period. Second, an application of KModSim, a network model, gave the amount of water allocation from each source to a consumer with consideration of economic supply. Finally, in a service area available to supply through conjunctive operation of existing inter-regional water supply networks within short distance, a conjunctive operation is useful for determining each transmission pipeline's service area and maximizing the effectiveness of optimizations in pumping operation time.

• Journal of Korean Society of Transportation
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• v.21 no.5
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• pp.73-81
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• 2003

The Government presented improvement plans such as "Traffic Accident Frequent Point" and "Hazardous Roads" to reduce traffic accidents on the increase after 1980s. In case of the hazardous roads, they are expressed by grades which are marked by geometric elements such as width, radius, grade. sight distance. and other environmental factors. As each business for improving roads goes by only focusing on improvement of geometric elements, excessive expense can be invested too much nowadays causing economical waste. Therefore, as improvement plans approached by economic access are needed, this paper shows the cost-effective improvement of the business to keep safety related to traffic accident and economical waste. The hazardous roads which authorized by Gwang-ju National Road Preservation Office of Construction and Transportation Ministry in 1995 for business for improvement of roads, were investigated before 1999. First of all, estimating traffic accident models are presented by using existed data statistically. The models help to maximize traffic accident decrease through control of the presented factor. Secondly, optimum construction cost of improvement is presented to prevent overcapitalization. However, this paper is limited because it was difficult to sort the data with various areas and to approach various ways.

• Journal of the Economic Geographical Society of Korea
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• v.11 no.4
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• pp.549-563
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• 2008

The purpose of this research is to identify the urban structure in Korea. Though there is research regarding urbanization, there is little regarding the urban structure of the Korean economy. In this paper, two issues will be discussed: the measurements of inter-city and intra-city structure in Korean Metropolitan Statistical Areas (MSAs), which is newly defined. First, the city size rank rule, widely known as Zipf’s Law, will illustrate Korean the inter-city structure. The city size rank rule gives an idea whether Korean MSAs are balanced or not. In general, Korea has a heavy concentration in the Seoul MSA in terms of population. It could be either that the Seoul MSA is too big or that the Busan MSA is too small or both. If this is the primacy problem, a decentralization policy is necessary. On the other hand, if it is a second city problem, development policies for the Busan MSA and Daegu MSA are more important. Next, the Korean intra-city structure will be discussed. The evolutions of the MSAs explain intra-city structure by analyzing population density function and the housing price function. Some large MSAs such as Seoul and Busan have experienced urban sprawl, while other MSAs have experienced urban concentration. The population density gradient by the distance from the ARC GIS shows the growth rate of a city. According to the Spatial Mismatch Index between population and employment, the Ulsan MSA, Gwangju MSA, and Suwon-Hwaseong-Osan MSA are more mismatched, while the Daejeon MSA and Incheon MSA are less mismatched. Therefore, these analyses of Korean urban structure are meaningful in developing regional policy.

• Economic and Environmental Geology
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• v.40 no.1 s.182
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• pp.87-101
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• 2007

A variety of informations obtained from satellite image, digital elevation relief map (DEM), borehole logging, televiewer, geophysical prospecting, etc were synthetically analyzed to investigate subsurface geological and structural characteristics and to evaluate geohazard pertinent to fault-damage in the Busan metropolitan city. It is revealed that the geology is composed of the Cretaceous andesitic$\sim$dacitic volcanics, gabbro, and granitoid and that at least three major faults including the Dongrae fault are developed in the study area. Based on characteristics of topography, fault-fractured zone, and isobath maps of the Quaternary sediments and weathered residuals of the basement, the Dongrae fault is decreased in its width and fracturing intensity of damaged zone from south toward north, and the fault is segmented around the area between the Seomyeon and Yangieong junctions. Meanwhile, we drew a geohazard sectional map using the five major parameters that significantly suggest damage intensity of basement by fault, i.e. distance from fault core, TCR, RQD, uniaxial rock strength, and seismic velocity of S wave. The map is evaluated as a suitable method to express the geological and structural characteristics and fault-damaged intensity of basement in the study area. It is, thus, concluded that the proposed method can contribute to complement and amplify the capability of the present evaluation system of rock mass.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.628-637
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• 2017

The automobile industry has developed Advanced Driver Assistance Systems (ADASs) to prevent traffic accidents and reduce the burden for drivers. One example is the Lane Keeping Assistance System (LKAS), which was developed for automotive vehicle systems for safety and better driving. The main system of the LKAS supports the driver while maintaining the vehicle within a lane. LKAS uses a radar sensor and camera sensor to collect information about the vehicle's position in the lane and send commands to the actuator to influence the lateral movement of the vehicle if necessary. Recently, vehicles equipped with LKAS have become commercially available. Test procedures for international LKAS evaluation are being discussed and developed by international committees, such as the International Organization for Standardization and United Nations Economic Commission for Europe. In Korea, an evaluation of LKASs for car safety is being planned by the Korean New Car Assessment Program. Therefore, test procedures should be developed for LKASs that are suitable for the domestic road environment while accommodating international standards. We developed a test scenario for LKASs and propose a formula for obtaining the target relative distance. To validate the methods, a series of experiments were conducted using commercially available vehicles equipped with LKAS.

• Economic and Environmental Geology
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• v.33 no.5
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• pp.391-404
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• 2000

This study investigated the geochemical characteristics of mine drainage discharged from an abandoned coal mine in the Hwasoon area. Surface water samples were collected from 23 locations along the Hancheon creek. The concentration of Zn and Cu in stream waters was highest at low pH (3.53), whereas the content of TDS and TDI was highest at high pH (7.78) due to the concentration of Ca, $HCO_3$ and $SO_4$. At the upstream site, the Ba, Fe, Mn, Zn, and $SO_4$ contents were relatively high but decreased significantly with the distance from the coal mine. On the contrary, the Na and $NO_3$ contents were low at the upstream site but increased downstream. Yellow precipitate material collected in the Hancheon consisted mainly of iron and LOI. This yellow precipitate was heated from 100 to $900^{\circ}C$ for 1 hour. With increasing temperature, the intensity of hematite peaks were sharply produced in X-ray pattern and the absorption band Fe-O of hematite increased in IR due to dehydration and melting. The yellow to brown precipitate and evaporite materials were collected by a air-dry from the acid mine water at the laboratory. After drying, the concentration of ions in the acid water samples increased progressively in oversaturation with respect to either gypsum, ferrohexahydrite or quenstedetite. The X-ray powder diffraction studies identified that the precipitated and evaporated materials after drying were well crystallized gypsum, ferrohexahydrite and quenstedetite. Diagnostic peaks used for identification of gypsum were the 7.65, 4.28, 3.03, 2.87 and 2.48$\AA$ peaks and those for ferrohexahydrite were the 5.46, 5.12, 4.89, 4.44, 4.05, 3.62, 3.46, 3.40, 3.20, 3.03, 2.94, 2.53, 2.28, 2.07, 1.88 and 1.86${\AA} peaks. The IR spectra with OH-stretching, deformation of $H_2O$and ${SO_4}^{2-}$stretching vibration include the existence of gypsum, ferrohexahydrite and quenstedetite in the precipitated and evaporite materials. In the SEM and EDS analysis for the evaporite material, gypsum with well-crystallized, acicular, and columnar form was distinctly observed.

• Economic and Environmental Geology
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• v.29 no.1
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• pp.45-55
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• 1996

Although the Dongjin Au-Ag-Cu mine had been abandoned since about forty years ago, the results of this study on the dispersion patterns and contamination level of heavy metals in the hydrologic system flowing via the waste rump show that the environmental impacts from the mine wastes are still significant. The stream water in the vicinity of the waste rump is severely acidified (pH 3.8 to 4.4) and highly enriched in various dissolved heavy metals. The heavy metal contents of the stream water and stream sediments are systematically attenuated with increasing distance from the mine area. However, it is worth to note that continuous attenuation of heavy metal contents in both media were reenriched in downstream area more than 800 m apart from the mine because it can be acted as a secondary source of heavy metal pollution. The heavy metals, especially Cd, Cu and Zn of polluted downstream sediments mainly occur in Fe-Mn oxides and organic materials, which indicates that these elements are the main pollutants from the waste rump of the Dongjin mine. The heavy metal contents of crops, such as sesame, perilla, red Pepper and brown rice, collected from the polluted farm land in the downstream area are lower than those of land plants from stream sides, but significantly higher in Cd, Cr, Cu and Zn than those from the unpolluted farm land. Especially, almost all of the crops in polluted farm land have been severly contaminated by Cd (>0.4 ppm). On the other hand, the heavy metal contents of the crops collected from refreshed farm land by means of a soil addition method shows significantly lowered level comparing with those of polluted area, which indicates that a soil addition method was effective for the refreshment of polluted farm land by toxic metallic pollutants. Wormwoods from this area showed very high contents in a11 the heavy metals even in unpolluted area (Cd > 1 ppm, Cr > 1 ppm, Cu > 11 ppm, Pb> 4 ppm, Zn > 55 ppm), indicating that a special caution must be payed when one takes ingest them.

• Economic and Environmental Geology
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• v.41 no.1
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• pp.81-92
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• 2008

Fonualei Rift and Spreading Center(FRSC) and Mangatolu Triple function(MTJ) caldera are located in northeastern part of Lau basin which is the active back-arc basin. Deep-tow and surface-tow magnetic surveys are carried out in FRSC. In deep-tow magnetic survey, to compensate for influence of uneven distance between bathymetry and sensor height, magnetic anomaly is continued upward to a level plane by using the Guspi method. We calculate crustal magnetization using Parker and Huestis's inversion algorithm, and try to find the hydrothermal vent and understand the structure of ocean floor crust. The result of deep-tow magnetic survey at FRSC showed that Central Anomaly Magnetization High(CAMH) recorded the max value of 4.5 A/m which is associated with active ridge. The direction of SSW-NNE corresponds with the direction of the principal spreading ridge in Lau basin. The low crustal magnetizaton$(174^{\circ}35.1'W,\;16^{\circ}38.4'S)$ of -4.0 A/m is supposed to correlate with submarine hydrothermal vent. Surface-tow magnetic data were collected in MTJ caldera$(174^{\circ}00'W,\;15^{\circ}20'S)$. The prevailing SSW-NNE direction of collapsing walls and the presence of CAMH at the center of caldera strongly indicate the existence of active spreading ridge in ancient times.

• Economic and Environmental Geology
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• v.43 no.2
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• pp.149-162
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• 2010

The most serious problem in oil stockpiles with artificial underground cavern is maintaining the stability of ground water system. In order to understand the ground water system around K-1 site, we determined the regional flow direction and level distribution of groundwater, and investigated the major geologic factors influencing their flow system. Reactivated surface along the contact between granite and gneiss, and fractures and faults along the long acidic dyke may contribute as important pathways for groundwater flow. Within K-1 site, groundwater level fluctuation is closely related to the rainfall events and injection from surface or influx water. In this project, the effect of groundwater pumping from the southern wells was examined. Based on equations relating water level drawdown to pumping rate at those wells, their pumped outflow of groundwater ranged from $80\;m^3$/day to less than $250\;m^3$/day. The modeling results with MODFLOW imply that the previous groundwater pumping at distance of 1.2 km may not affect the groundwater level variations of the K-1 site. However, continuous pumping work at quantity over $250\;m^3$/day in this area will be able to affect the groundwater system of the K-1 site, particularly along the acidic dyke.