• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.2
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• pp.34-43
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• 2009

Based on previous research on ways of reducing an urban heat island phenomenon via an introduction of wind corridors, I conducted this study to see what influence a change in land cover arising of or going through urbanization has on wind corridors of urban space. As a target place, I chose Daegu city where is a representative extreme heat place in Korea and has been also largely expanded in size by incorporating its neighboring areas since the 1980s, expecially Dalseo District whose surface temperature gap is large. The population of Dalseo District has been sharply increased since its creation as a new administrative district in 1988. I studied on the urban microclimate change for a 20-year period by using satellite images on summer months in 1987, 1997 and 2007 in time frames. The finding of this study found that a reduction of natural land cover and an increase of artificial land cover serves as a disadvantageous factor for cold air creation and flowing and strikingly lowers the amount and height of cold air in the downtown area. It seemed that the cold air creation and flowing functions are influenced by land cover. In order to steadily create cold air and secure its flowing, it is thought that urban development or urban regeneration should be implemented by analysing the characteristics of the space surrounding the city. By doing so, a pleasant and healthy city could be formed.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.2
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• pp.120-131
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• 2009

This study measured the centripetal force and effective scope of the population spread from urban center and subcenters in order to diagnose the urban spatial structure of the formation of a multicentric city structure in Busan. The study analyzed the variability of the determination coefficient value (R square) with a negative exponential function derived from the population density model by extending the circular region into 5-km units. The aim of this study was to measure changes in the effective scope of the population centripetal force of the urban center and subcenter in 5-year intervals from 1995 to 2005 using census data. The explanatory adequacy of the population density function was examined with the bias of the function to calculate the distance error between the real location of the urban center and the optimal location, according to the population density function. To summarize the results, the value for the area of Jungangdong showed a continuous reduction, whereas Seomyeon (Bujeondong) maintained explanatory adequacy without a large change. As a whole, Busan was in the process of continuous diversification, in spite of its reduced population. Therefore, it appears necessary to strengthen the function of the urban center and subcenter and to supply adequate dwelling zones close to downtown to form a more efficient urban spatial structure. The results of the present study will be utilized as basic data for the formulation of a political approach to the efficient reorganization of spatial structure by correlating concrete spatial information with the population variability of Busan's urban center and subcenter.

• Journal of Korea Water Resources Association
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• v.49 no.6
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• pp.519-528
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• 2016

Frequently torrential rain is occurred by climate change and urbanization. Urban is formed with road, residential and underground area. Without detailed topographic flooded analysis consideration can take a result which are wrong flooded depth and flooded area. Especially, flood analysis error of population and assets in dense downtown is causing a big problem for establishments and disaster response of flood measures. It can lead to casualties and property damage. Urban flood analysis is divided into sewer flow analysis and surface inundation analysis. Accuracy is very important point of these analysis. In this study, to confirm the effects of the elevation data precision in the process of flooded analysis were studied using 10m DEM, LiDAR data and 1:1,000 digital map. Study area is Dorim-stream basin in the Darim drainage basin, Sinrim 3 drainage basin, Sinrim 4 drainage basin. Flooding simulation through 2010's heavy rain by using XP-SWMM. Result, from 10m DEM, shows wrong flood depth which is more than 1m. In particular, some of the overflow manhole is not seen occurrence. Accordingly, detailed surface data is very important factor and it should be very careful when using the 10m DEM.

• Journal of the Economic Geographical Society of Korea
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• v.14 no.4
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• pp.506-523
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• 2011

Since the 1990s, the handmade shoes industrial agglomeration district has formed in the city center, Hyangchon-dong, Jung-gu in Daegu. This paper aims to examine the formation process, to analyze the viability, and to propose policy implications of manufacturing industrial districts in a city center through studying this industrial district. The district's creation began as the result of the dissolution of local production and marketing system of handmade shoes in the 1980s, the excellent accessibility of the location and an inexpensive rent. The district's core viability lies in the external economies derived from local networks through social divisions of labor of production and marketing systems. Because of the lack of organizers of the social division of labor and 'integrated production system done by single business', the effect of external economies created by the social division of labor is limited. To get over this limitation, the district should to be restructured into a 'cultural street of leather crafts' as a part of 'making modern historical and cultural belt' programs within Daegu downtown regeneration policies. To support the restructuring, public assistant measures such as the establishment of a corporate services center should be strengthened.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.9
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• pp.811-820
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• 2012

GNSS signal is vulnerable to jamming signal because of well-known signal structure and weak signal power. For these reasons, the need for analysis of jamming effects and anti-jamming techniques of is increasing. In this paper, a GNSS signal generator is designed which includes a radio wave propagation model for six kind of tactical environments and a body masking model for the reception environment of a vehicle. The radio wave propagation model for downtown, rural, forest, coastline, waste land and snow or ice area is designed using two-ray model. The body masking model is designed the effect which the antenna is affected by the reception environment of a vehicle and radiation pattern from a user configuration. The performance of generated signals from the GNSS signal generator considering reception environment of a vehicle is evaluated by a commercial GPS L1 receiver(NordNav) in normal and jamming environment. Also, the generated GNSS signal is compared to a commercial GPS L1 H/W based RF signal generator(STR4500). The results show that the designed GNSS signal generator in a normal environment compared to the same navigation performance. In jamming environment, it is shown that the body masking effect and GNSS signal acquisition and tracking loss in compliance with the jamming signal are precisely working in the reception environment of a vehicle.

• Journal of the Korean GEO-environmental Society
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• v.21 no.12
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• pp.35-41
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• 2020

Recently, underground spaces have been developed variously due to the concentration of the building structure in downtown area and reconstruction of the apartment. However, various problems such as differential settlement are occurring in the waterproof and reinforcement construction. In grouting method, which is frequently used for the ground reinforcement, quality control was performed by measuring the injection quantity of grouting materials and performing laboratory tests using boring samples, but it is difficult to determine whether the ground reinforcement has been performed properly during the construction stage. In order to solve this problem, a research is needed to carry out quality control by measuring electric resistivity after grouting is performed using grouting materials mixed with conductive materials. In this research, as a basic study of the new grouting method using conductive materials, uniaxial compression tests were performed using cement specimen with 0, 3, 5, 7% of carbon fiber to evaluate the effect of conductive material on the performance of grouting material. Based on the test results, the uniaxial compressive strength is increased with the mixed proportion of the carbon fiber increase. Furthermore, the carbon fiber can also affect on the early-strength of the grouting materials.

• Korean Journal of Construction Engineering and Management
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• v.21 no.6
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• pp.16-26
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• 2020

Road Pavement Maintenance Work is generated in a variety of different field conditions, and it is difficult to calculate the construction cost because there are no detailed criteria when preparing the estimated construction cost. Unlike new pavements, Road Pavement Maintenance has to be constructed with operating vehicles, and there are many differences in productivity depending on urban areas, limited work hours, night-time, construction area, etc. To compensate for this, the standard for calculation of construction cost provides additional charges for the number of lanes, residential areas, working hours, and night work, but it applied differently depending on construction officials. In this study, construction cost estimation standards that can properly reflect the conditions of the site was investigated for major types of Road Pavement Maintenance work. The site was investigated and analyzed mainly for many construction sites with 'overlay of asphalt after cutting', 'restore surface', 'repair of pavement', and 'recovery of roadway'. The criteria for the application of construction volume separately according to working hours, public places, and land area including extra charges for basic downtown and residential area. The hours of operation were divided into three types(7 hours, 5 hours, 3 hours) excluding movement and preparation time, and each type provided a coefficient for dividing the area of the construction site into five types. The construction cost calculation method based on the construction purpose is site conditions is proposed accordingly, and it is deemed that a plan for the designer to calculate the construction cost has been prepared in consideration of the site conditions.

• Explosives and Blasting
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• v.35 no.1
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• pp.43-52
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• 2017

Mountain and hill areas occupy by more than 70% in South Korea and Rock drilling should be applied in order to reduce noisy & vibration from massive civil engineering business such as road expansion, high-way construction, subway construction and construction of site renovation such as a newly-built & re-development of apartment, newly-built of high-rising building in downtown area. As Blasting noise & vibration such as vibration, noise, fly rock etc caused by blasting operation from large small scale construction occurs, neighboring residents who demand the compensation file a civil complaint so that the business reach a deadlock. As the excavation method for these areas, There are blasting of micro-vibration, mechanical excavation method(Rock splitter, Breaker etc), similar blasting method(plasma, gel fragmentation etc) to date. In this study, we are trying to find the feature & performance which get improved economic feasibility & construct ability through improving sympathetic detonation of New KINECKER-I used in blasting of micro-vibration & formulation and would provide convenience for use by introducing standard blasting pattern & construction method. Also, checked and confirmed all the blasting with connecting cap has been cleary detonated.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.4
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• pp.29-38
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• 2016

The maps produced by the NGII(geographical information institute) are composed of 1/1,000, 1/2,500, 1/5,000 large scale maps, 1/25,000, 1/50,000 and smaller scale maps. 1/1,000 digital map, as the most large-scale digital map made by the NGII, has been constructed with the beginning of NGIS(national geographic information System) Project in 1995. However, 1/1000 digital maps have been not produced by the fundamental survey on the basis of systematic planning at the national level, but a lot of parts have been constructed by the public survey for the purpose of the fiscal year of the local governments. Also, these maps have been not regularly updated because of big budget. In this study, we investigated problems related to the construction status, system, and area, and suggested plans that can improve these problems. As the improvement plan, we proposed a nationwide three regionalization for short-term modification and long-term regular update, reset of core downtown boundaries based on topographical features, diversification of budget execution method and an improved execution system.

• Journal of the Korean Geosynthetics Society
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• v.16 no.3
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• pp.51-62
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• 2017

For the purpose of the study, of the 76 areas subject to preliminary concentrated management on sediment disaster in the downtown area, 9 areas were selected as research areas. They were classified into three stratified rock areas (Gyeongsan City, Goheung-gun and Daegu Metropolitan City), three igneous rock areas (Daejeon City, Sejong Special Self-Governing City and Wonju City) and three metamorphic rock areas (Namyangju City, Uiwang City and Inje District) according to the characteristics of the bedrock in the research areas. As for the 9 areas, analyses were conducted based on tests required to calculate soil characteristics, a predictive model for root adhesive power, loading of trees and on-the-spot research. As for a rainfall scenario (rainfall intensity), the probability of rainfall was applied as offered by APEC Climate Center (APCC) in Busan. As for the prediction of landslide risks in the 9 areas, TRIGRS and LSMAP were applied. As a result of TRIGRIS prediction, the risk rate was recorded 30.45% in stratified rock areas, 41.03% in igneous rock areas and 45.04% in metamorphic rock areas on average. As a result of LSMAP prediction based on root cohesion and the weight of trees according to crown density, it turned out to a 1.34% risk rate in the stratified rock areas, 2.76% in the igneous rock areas and 1.64% in the metamorphic rock areas. Analysis through LSMAP was considered to be relatively local predictive rather than analysis using TRIGRS.