• Transportation Technology and Policy
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• v.8 no.4
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• pp.89-96
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• 2011

• Proceedings of the KGS Conference
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• 2006.06a
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• pp.61-63
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• 2006

• Proceedings of the KOR-KST Conference
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• 1999.10a
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• pp.379-384
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• 1999

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.673-677
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• 2009

In this paper, a transmitting process of a sequence of holograms describing 3D moving objects over the communicating wireless-network system is presented. A sequence of holograms involves holograms is transformed into a bit stream data, and then it is transmitted over the wireless LAN and Bluetooth. It is shown that applying this technique, holographic data of 3D moving object is transmitted in high quality and a relatively good reconstruction of holographic images is performed.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.43-48
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• 2019

We design a reconfigurable optical node for metropolitan WDM networks, and numerically study the capability of the node in the optical signal level. Unlike a long-haul WDM system, major limitations of metropolitan WDM systems are power loss, fiber dispersion and optical signal-to-noise ratio(OSNR) degradation due to EDFAs. Therefore, we include the behaviors of transmitter and receiver, and fiber, EDFAs, and optical filters(MUX/DeMux) in numerical simulations with varying parameters over wide range. From simulation results, we can identify the maximum span numbers for OC-48 and OC-192 to achieve $BER<10^{-12}$ using the node structure at various received powers and residual dispersions.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.5
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• pp.459-471
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• 2009

Air Monitoring Network(11 urban stations) is operated to measure ambient air quality in Daegu city. The urban air monitoring stations include 6 in residence area, 3 in industrial area, 1 in commercial area, and 1 in green area. In this study, hourly data (2006. 1. 1~2008. 12. 31) of $PM_{10}$ were measured at 11 urban air monitoring stations. $PM_{10}$ mean concentrations were high in fall and winter because of low wind speed and many haze days. The number of exceeding the daily standard of $PM_{10}$ in industrial area was approximately twice as many as that in residence area. $PM_{10}$ concentrations and visibility were influenced significantly by wind speed. Wind speed and visibility were below 1.8 m/s and 10 km, respectively when $PM_{10}$ concentrations were over $120{\mu}g/m^3$. $PM_{10}$ concentrations were high when haze was observed. The mean concentrations of $PM_{10}$ were $104{\pm}41.3{\mu}g/m^3$, $63{\pm}35.1{\mu}g/m^3$, and $49{\pm}26.9{\mu}g/m^3$, respectively when haze, mist and clear were observed.

• Journal of the Economic Geographical Society of Korea
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• v.7 no.1
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• pp.29-43
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• 2004

In this paper, we tries to investigate whether there are some differences of the characteristics between venture business in the metropolitan area and in the local area. We set up some hypotheses on the regional characteristics of venture business and test those using the raw data of Small and Medium Business Administration (SMBA) survey on the management of venture business. Our main findings are as follows: First, we analyze the industrial composition of ventures by region and find that in the metropolitan area high-technology venture business which is belong to software, or information, or communication industries is given much weight. But in the provinces, ventures belong to traditional manufacturing industries is given much weight. Second, we compared the characteristics of business network by region and find that the ventures in the metropolitan area are active in technical cooperation among companies and want strategic tie-ups in marketing field, whereas the ventures in the provinces are active in technical cooperation with university and want strategic tie-ups in technical development field. Third, ventures in the metropolitan area are more excellent in technical development and management than ventures in the provinces.

• Journal of the Korean Geographical Society
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• v.51 no.4
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• pp.541-558
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• 2016

Landfill has been a long pending issue in the Seoul Metropolitan Region since it was created. Adopting Painter's notion of "territory-effect," this paper analyzes the network formation and change of diverse actors and territory as an effect of networked relations according to four periods from the creation of the landfill to current extension of landfill use. The results are as followed. First, the network formation and composition of major actors has been changed together with historical-geographical conditions. Second, these networks created territory as an effect and re-articulated the configuration of conflicts and solidarity of diverse actors. Third, territory created as an network-effect are different in each period, and is continuously reterritorializing. These findings suggest that territory is never complete and always in the making.

• Journal of the Korean Regional Science Association
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• v.37 no.2
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• pp.49-61
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• 2021

Long-distance commuting is a problem as people living in Gyeonggi-Incheon contitue to commute to Seoul in the Seoul metropolitan area. To solve this problem, policies in the region are aiming for a self-sufficient zone formation plan and a compact city. However, urban problems caused by such long-distance commuting continue. This appears to be due to excessive density and Seoul-dependent networks. However, existing studies have focused on individual cities despite the importance of inter-city interactions, and had limitations in not considering the characteristics of the Seoul-dependent networks. Therefore, the purpose of this study is to empirically analyze the effect of the compactness on commuter travels by comprehensively considering the interactions between cities within the region using multiple regression. As a result of the analysis, it was found that that commuting efficiency increases when a network of more than a certain size is formed, and the results imply that policies should focus on fostering network centers in Incheon and Gyeonggi regions, which are outside the metropolitan area, and consider to expand the transportation networks at the regional level.

• Journal of the Korean Society for Railway
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• v.20 no.3
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• pp.413-422
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• 2017

In this study we investigate the importance of the subway station using network centrality measures. For centrality measures, we have used betweenness centrality, closeness centrality, and degree centrality. A new measure called weighted betweenness centrality is proposed, that combines both traditional betweenness centrality and passenger flow between stations. Through correlation analysis and power-law analysis of passenger flow on the Seoul metropolitan subway network, we have shown that weighted betweenness centrality is a meaningful and practical measure. We have also shown that passenger flow between any two stations follows a highly skewed power-law distribution.