• ETRI Journal
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• v.45 no.5
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• pp.768-780
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• 2023

The application of unmanned aerial vehicles (UAVs) has recently attracted considerable interest in various areas. A three-dimensional multiple-input multiple-output concentric two-hemisphere model is proposed to characterize the scattering environment around a vehicle in an urban UAV-to-vehicle communication scenario. Multipath components of the model consisted of lineof-sight and single-bounced components. This study focused on the key parameters that determine the scatterer distribution. A time-variant process was used to analyze the nonstationarity of the proposed model. Vital statistical properties, such as the space-time-frequency correlation function, Doppler power spectral density, level-crossing rate, average fade duration, and channel capacity, were derived and analyzed. The results indicated that with an increase in the maximum scatter radius, the time correlation and level-crossing rate decreased, the frequency correlation function had a faster downward trend, and average fade duration increased. In addition, with the increase of concentration parameter, the time correlation, space correlation, and level-crossing rate increased, average fade duration decreased, and Doppler power spectral density became flatter. The proposed model was compared with current geometry-based stochastic models (GBSMs) and showed good consistency. In addition, we verified the nonstationarity in the temporal and spatial domains of the proposed model. These conclusions can be used as references in the design of more reasonable communication systems.

• Spatial Information Research
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• v.22 no.2
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• pp.73-87
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• 2014

The fact that the limits of information recency, diversity, and usability are mainly caused by the supply oriented geospatial data and service development is commonly recognized. It is recently tried to overcome the limits by facilitating user experience and VGI(Volunteered Geographic Information) in several geospatial web services. This study suggests 10C framework of geospatial web service for VGI through review and examination of previous research. Based on the 10C framework, the value chain system of 23 use cases relevant to the geospatial web service involving the creation of user's VGI is investigated. The result of the value chain analysis is applied to examine and formulate the strategies to generate value addition from public spatial information with respect to creation, aggregation, delivery, and consumption process of VGI.

• Land and Housing Review
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• v.5 no.4
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• pp.271-279
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• 2014

Most CPTED have currently applied to newly developing apartment complexes. but developed apartment complexes are relatively vulnerable to crime due to lack of CPTED considerations. This study has examined both crime prevention preferences space and facilities considering the cost of CPTED. This study suggests plans of the CPTED application to the developed apartment complex without changing existing physical environment. The entrance of apartment complexes, underground parking lots, parks and rest areas, elevators, stairs and aisle in side of the buildings should be given top priority. The next are pedestrians roads, fences, main entrance on the first floor. Lastly, shopping store facilities and the ground parking lots are among the last ones.

• Korea Science and Art Forum
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• v.37 no.3
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• pp.365-376
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• 2019

Now, our urban space is composed of all kinds of sculptures that lost its individual charm in trend flows and street furniture standardized by the integrated design of standardized franchises and similar architectures per each region and autonomous districts. This study was to introduce the concept called the 'community furniture' in the urban environment that there is no an identity of the regional culture and a sense of place because of the mostly similar street environment. The purpose of this study is to propose the concept called the 'community furniture' referred to as public facilities that imply specific identities of some regions that have became the community art expanded into necessary facilities of urban composition as bus shelter's universal convenience and functionality have been preferentially handled and its regional identities are reflected. For doing this, this study fulfilled application alternatives of community furniture design's basic principles after examining the storytelling process of local cultural heritages and analyzing domestic and foreign cases of bus shelters. Results of this study are as follows. First, convergent synergy effects in information and culture and art sectors could be expected as bus shelters visually deliver storytelling factors that imply locally related images. Second, space and place's characteristics and sustainable design concepts embody local characteristics. They can suggest directions for vitalizing urban environment designs by being in harmony with surrounding environments. Third, it is expected that realizing distinctive places is possible as bus shelters with local communities' aesthetic consciousness and regionality are composed of new street spaces.

• Journal of Korean Society for Geospatial Information Science
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• v.3 no.2 s.6
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• pp.43-61
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• 1995

The national land use plan that targets the whole national land and all kinds of urban plans that targets a city or a part of city must be performed continuously now and after that. Therefore, the importance of land use plan, that is included in those plans, is very big and crucial. This study scrutinizes the detail zoning land suitability analysis which bases on urban basis plan and the GSIS application plan about allocation, applied various basic theory which is arranged in that course to study area, and try to develop the land use suitability analysis system, a application system The programing language used in system development is the AML of ARC/INFO. On this study, the results divide into four parts. First, we develop the land use suitability analysis system and can simplify and automatize a complicated analysis course and this system will be more useful to the land use suitability analysis. Second, the analysis range is expanded, considering the circumstance environmental factor of planning area outside. So we can implement more comprehensive analysis. Third, we apply a precedency conception and a legal restrictive element that base on urban characteristics and urban space structure theory to this study, develop a computerized method about distributive method, and can allocate the detail zone in the various ways. Finally, the next studies that can clear the detail zone suitability criteria and the correlation of the relationship of materials are essential to improve the accuracy and confidence in this analysis.

• Architectural research
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• v.18 no.4
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• pp.171-178
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• 2016

Architectural utility in Richard Neutra's early twentieth century modern school design was paramount in progressively shaping salience of academic institutions, in part to move beyond neoclassical traditions in style based design. The intention being to address school and community through modern architectural solutions. Expanding on Neutra's practice, the planning and design of new public schools in Los Angeles, are advocating the integration of institutional and public spaces. This research will document through qualitative analysis of institutional design within transitioning neighborhoods, a utilitarian approach that has become foundational for positive urban change. The focus of this research will reflect upon contemporary schools designed by DalyGenik Architecture, Coop Himmelblau and Michael Maltzen Architecture. Comparing with Neutra's early modernist approach, the selected case studies will address material and spatial applications having redefined functional relationships of interior space, architectural envelope and an interconnected public realm. A dynamic peripheral condition in new school design has emerged with the elimination of decorative adornment, clarifying utilitarian intentions of institutional service to and the rejuvenation of public realms and community spaces.

• International Journal of High-Rise Buildings
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• v.3 no.3
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• pp.173-183
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• 2014

Nakanoshima Festival Tower is a 200 m high-rise complex building which contains a renewed 2700-seat capacity concert hall known as "Festival Hall" and offices including headquarter of a news company. In order to build up an office tower on the hall which requires large open space, a giant truss system is employed. The giant trusses being composed of mega-trusses and belt-trusses support all the building weight above them and transfer the load to the outside of the hall. The building also requires high seismic resistance performance for a news company. Application of mid-story seismic isolation enables the building to satisfy high-level seismic resistance criteria.

• Tunnel and Underground Space
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• v.6 no.1
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• pp.57-63
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• 1996

The goal of this study is to develop a simulation model of the pollutant dispersion in vehicle tunnels, which can be utilized to optimize the tunnel ventilation system. Contaminant dispersion is modelled using a FDM solution of advective diffusion equation. Taking into consideration the local vehicle emission rates by year, it is user-oriented and its logic is generalized. Therefore, differences in the ventilation scheme can be easily adapted. The results of its application to a urban tunnel show that the relative errors are 1.1~6.8% for the natural velocity, 1.3% for the traffic-induced velocity and 2.9% for the total air quantity. Simulated CO concentrations along the entire tunnel show about 13% of the relative error.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.5
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• pp.89-99
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• 2019

In this study, we estimated the spatially-distributed soil moisture at the high resolution ($10m{\times}10m$) using the satellite-based Sentinel-1A/B SAR (Synthetic Aperture Radar) sensor images. The Sentinel-1A/B raw data were pre-processed using the SNAP (Sentinel Application Platform) tool provided from ESA (European Space Agency), and then the pre-processed data were converted to the backscatter coefficients. The regression equations were derived based on the relationships between the TDR (Time Domain Reflectometry)-based soil moisture measurements and the converted backscatter coefficients. The TDR measurements from the 51 RDA (Rural Development Administration) monitoring sites were used to derive the regression equations. Then, the soil moisture values were estimated using the derived regression equations with the input data of Sentinel-1A/B based backscatter coefficients. Overall, the soil moisture estimates showed the linear trends compared to the TDR measurements with the high Pearson's correlations (more than 0.7). The Sentinel-1A/B based soil moisture values matched well with the TDR measurements with various land surface conditions (bare soil, crop, forest, and urban), especially for bare soil (R: 0.885~0.910 and RMSE: 3.162~4.609). However, the Mandae-ri (forest) and Taean-eup (urban) sites showed the negative correlations with the TDR measurements. These uncertainties might be due to limitations of soil surface penetration depths of SAR sensors and complicated land surface conditions (artificial constructions near the TDR site) at urban regions. These results may infer that qualities of Sentinel-1A/B based soil moisture products are dependent on land surface conditions. Although uncertainties exist, the Sentinel-1A/B based high-resolution soil moisture products could be useful in various areas (hydrology, agriculture, drought, flood, wild fire, etc.).

• Journal of Korean Society of Transportation
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• v.36 no.1
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• pp.23-37
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• 2018

In recent years, it is very difficult to construct and expand new infrastructures in a city center because of long-term low growth and lack of space due to urban overcrowding. So, there is a need to study a variety of Retrofitting techniques and urban applications that can lead to sustainable development while efficiently utilizing existing facilities. 'Retrofit' means a sustainable urban retrofitting as a directed alteration of the structures, formations and systems of existing facilities to improve energy, water and waste efficiencies. In this study, we applied a hierarchical network design technique that can reflect the structural hierarchy of a city to study how to retrofit public transportation routes in Seoul. The hierarchical network design means dividing the hierarchy according to the functions of hubs and connecting different hierarchies to form a hierarchical network. As a result of comparing the application results of various retrofitting scenarios of public transport, the differences of daily PKT and PHT by about 2.6~3.2% less than before the improvement address that the convenience of passengers is increased. Therefore, it is expected that if the route planning is established according to the proposed method, it will increase the number of passengers and the operational efficiency by the improved convenience of public transit passengers.