• Steel and Composite Structures
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• v.23 no.4
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• pp.453-464
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• 2017

The square tubed-reinforced concrete (TRC) column is a kind of special concrete-filled steel tube (CFST) columns, in which the outer thin-walled steel tube does not pass through the beam-column joint, so that the longitudinal steel reinforcing bars in the RC beam are continuous through the connection zone. However, there is a possible decrease of the axial bearing capacity at the TRC column to RC beam connection due to the discontinuity of the column tube, which is a concern to engineers. 24 connections and 7 square TRC columns were tested under axial compression. The primary parameters considered in the tests are: (1) connection location (corner, exterior and interior); (2) dimensions of RC beam cross section; (3) RC beam type (with or without horizontal haunches); (4) tube type (with or without stiffening ribs). The test results show that all specimens have relatively high load-carrying capacity and satisfactory ductility. With a proper design, the connections exhibit higher axial resistance and better ductility performance than the TRC column. The feasibility of this type of connections is verified.

• Structural Engineering and Mechanics
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• v.78 no.1
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• pp.87-102
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• 2021

Long span cross-rope suspension structure is an innovative structural system evolved from typical Cross-Rope Suspension (CRS) guyed tower, a type of supporting system with short span suspension cable supporting overhead power transmission lines. In mountainous areas, the span length of suspension cable was designed to be extended to hundreds or over one thousand meters, which is applicable for crossing deep valleys. Vortex Induced Vibration (VIV) of overhead power transmission lines was considered to be one of the major factors of its fatigue and service life. In this paper, VIV and its controlling by Stockbridge damper for long span CRS was discussed. Firstly, energy balance method and finite element method for assessing VIV of CRS were presented. An approach of establishing FE model of long span CRS structure with dampers was introduced. The effect of Stockbridge damper for overall vibration of CRS was compared in both theoretical and numerical approaches. Results indicated that vibration characteristics of conductor in long span CRS compared with traditional tower-line system. Secondly, analysis on long span CRS including Stockbridge damper showed additional dampers installed were essential for controlling maximum dynamic bending stresses of conductors at both ends. Moreover, factors, including configuration and mass of Stockbridge damper, span length of suspension cable and conductor and number of spans of conductor, were assessed for further discussion on VIV controlling of long span CRS.

• Journal of the Economic Geographical Society of Korea
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• v.21 no.4
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• pp.409-424
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• 2018

Since the 1950s, many of the traditional industrial cities of advanced economies in Europe and North America were affected by a series of de-industrialization. The de-industrialization process, characterized by company shut-downs and massive lay-offs, has resulted in high unemployment rates and massive redundancies in physical infrastructure. Since the 1980s, many of the old industrial cities have attempted to overcome such problems. However, it has been found that not many of the cities are found to be successful. The City of Dortmund, one of the core cities of the large German industrial conurbation of the past, the Ruhr, is found to be an exceptional case demonstrating a clear success in overcoming deindustrialization problems. The City in fact strategically pursued transforming backbone of its economy from steel-making, coal-mining and beer-brewery to high-technology and future-oriented industries, based on microsystems, biomedical, electronic logistics and information technology. This paper attempts to analyse the processes and outcomes of transforming Dortmund beginning from the 1980s to articulate the roles of the agencies contributing to the success.

• Journal of the Society of Disaster Information
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• v.17 no.1
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• pp.68-80
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• 2021

Purpose: In this study, potential demographic, social, and economic factors causing tuberculosis were identified, and eight cities in South Chungcheong Province were compared and analyzed with the IPA method. Method: The factors potentially affecting the prevalence of tuberculosis were categorized demographically, socially, and economically, and selected through brainstorming. Furthermore, potential factors affecting tuberculosis were derived using the revised IPA. Based on this analysis, areas with a potential risk of tuberculosis were classified, and the following policy implications were suggested. Result: The analysis found the three cities of Nonsan, Boryeong, and Gongju to have the highest potential risk of tuberculosis, and the frequency of potential risk factors in the above three cities to be 6 or more. Thus, an urgent policy response to prevent tuberculosis in these regions is required. Conclusion: According to the results of this study, it is necessary to take potential risk factors into account when promoting tuberculosis prevention policies and projects in South Chungcheong Province.

• Journal of the Korean Regional Science Association
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• v.37 no.2
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• pp.35-48
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• 2021

Modern cities are changing to 'smart cities' dramatically with the introduction and development of the fourth industrial revolution technologies. Among these technologies blockchain is unique because it not only embraces technological innovation but also societal revolution. Therefore, blockchain is expected to play a pivotal role for contributing comprehensive development of smart city. The current research and policy atmosphere in Korea, however, is that blockchain is just a new technology and its broader impacts are overlooked. This study argues that blockchain has significant effects on smart cities not only from technological perspectives but also from social, economic, institutional, governmental perspectives. Further, this study suggests three categories that blockchain can help the development of smart city: technology, socio-economic, and governance, with examples of existing blockchin projects. However, these projects have been builting separately without any interaction under the common hood of 'smart city'. To emhance influences of blockchain on smart cities in positive ways, private companies, policy maker, and citizend are supposed to consider and discuss about publi sector's blockchain that is commonly used in at the smart city level.

• International Journal of Computer Science & Network Security
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• v.21 no.6
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• pp.107-118
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• 2021

The deployment of 5G is in full swing, with a significant yearly growth in the data traffic expected to reach 26% by the year and data consumption to reach 122 EB per month by 2022 [10]. In parallel, the idea of smart cities has been implemented by various governments and private organizations. One of the main objectives of 5G deployment is to help develop and realize smart cities. 5G can support the enhanced data delivery requirements and the mass connection requirements of a smart city environment. However, for specific high-demanding applications like tactile Internet, transportation, and augmented reality, the cloud-based 5G infrastructure cannot deliver the required quality of services. We suggest using multi-access edge computing (MEC) technology for smart cities' environments to provide the necessary support. In cloud computing, the dependency on a central server for computation and storage adds extra cost in terms of higher latency. We present a few scenarios to demonstrate how the MEC, with its distributed architecture and closer proximity to the end nodes can significantly improve the quality of services by reducing the latency. This paper has surveyed the existing work in MEC for 5G and highlights various challenges and opportunities. Moreover, we propose a unique framework based on the use of MEC for 5G in a smart city environment. This framework works at multiple levels, where each level has its own defined functionalities. The proposed framework uses the MEC and introduces edge-sub levels to keep the computing infrastructure much closer to the end nodes.

• Journal of Environmental Impact Assessment
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• v.31 no.3
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• pp.161-172
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• 2022

This study attempts to understand urban evolution characteristics through suburban development cases considered as a contemporary urban issue. Methods are (1) Urban Expansion Intensity Index (UEII) for the 9 cities in the Korea (1980-2010) & 49 cities in the US, (2) Morphological Spatial Pattern Analysis(MSPA) and Entropy for the developed areas in the Chicago Metro (2019). Results are (1) a suburban development could be understood the universal characteristics, (2) the characteristics of the whole region might be appeared to be in a different direction from the characteristics of its sub-cities. Implications are (1) Suburban expansion can be understood as a functionally well served urban change phenomenon and it is important to focus on the functions of sub-level cities, (2) the urban evolutionary perspective makes a difference from the developmental growth perspective. The extensive empirical studies will be beneficial for better understating of urban evolution.

• Journal of People, Plants, and Environment
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• v.24 no.2
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• pp.219-227
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• 2021

Background and objective: Urban street trees play an important role in carbon reduction in cities where greenspace is scarce. There are ongoing studies on carbon reduction by street trees. However, information on the carbon reduction capacity of street trees based on field surveys is still limited. This study aimed to quantify carbon uptake and storage by urban street trees and suggest a method to improve planting of trees in order to increase their carbon reduction capacity. Methods: The cities selected were Sejong, Chungju, and Jeonju among cities without research on carbon reduction, considering the regional distribution in Korea. In the cities, 155 sample sites were selected using systematic sampling to conduct a field survey on street environments and planting structures. The surveyed data included tree species, diameter at breast height (DBH), diameter at root collar (DRC), height, crown width, and vertical structures. The carbon uptake and storage per tree were calculated using the quantification models developed for the urban trees of each species. Results: The average carbon uptake and storage of street trees were approximately 7.2 ± 0.6 kg/tree/yr and 87.1 ± 10.2 kg/tree, respectively. The key factors determining carbon uptake and storage were tree size, vertical structure, the composition of tree species, and growth conditions. The annual total carbon uptake and storage were approximately 1,135.8 tons and 22,737.8 tons, respectively. The total carbon uptake was about the same amount as carbon emitted by 2,272 vehicles a year. Conclusion: This study has significance in providing the basic unit to quantify carbon uptake and storage of street trees based on field surveys. To improve the carbon reduction capacity of street trees, it is necessary to consider planning strategies such as securing and extending available grounds and spaces for high-density street trees with a multi-layered structure.

• Journal of Digital Convergence
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• v.20 no.5
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• pp.375-381
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• 2022

The DEA-BCC model. And the Malmquist index have been used, from static and dynamic perspectives, to measure the eco-efficiency of 30 cities and provinces in China from 2011 to 2020. The results shows that: the average static eco-efficiency of 30 cities and provinces in China is 0.643. Differences exists all over China. While Shanghai and Beijing are ecologically efficient, other 28 cities and provinces are faced with different extents of inefficiency. There are also differences among regions, which generally show the spatial distribution pattern with high efficiency in the eastern regions while low in the western regions. The Malmquist index of eco-efficiency in total 30 cities and provinces shows a healthy growth trend, and the technological progress. Acts as its main driving force. Therefore, eastern regions should enhance the. radiation capacity, strengthen the synergy among regions, give full play to. The advantages of each regions. It is sensible to improve the eco-efficiency by means of optimizing the industrial structure, enhancing the technological level and improving eco-efficiency of China and realizing green development.

• Korea Science and Art Forum
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• v.26
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• pp.339-351
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• 2016

This study analyzes convention tourism destination brand slogans focusing on the international convention cities. Data were collected from official tourism web sites of 190 cities which hosts more than ten international meetings in 2013. One hundred and six destination brand slogans were identified. Specifically, the researchers attempt to carry out content analysis of the linguistic and visual expressions of the slogans. Results indicated that in terms of linguistic expressions, most of slogans adopted word or phrase patterns pursuing brevity. In the brand slogan spectrum, nearly half of slogans are common type which didn't express destinations' specific attributes and benefits properly. And the most frequently used key words in the slogans are 'visit' and 'city'. While in terms of visual expressions, about 70% of slogans adopted typography for explicitness and 60% of them utilized human and natural resources as visual signs for building up unique images. Based on the results, implications for creating effective convention tourism destination brand slogans were also discussed.