• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.29-37
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• 2009

As the level of the ambient air quality becomes increasingly important, transportation management strategies tend to incorporate air quality standards into their measure of effectiveness. However, previous research efforts did not pay much attention to the empirical relationships between traffic volume and air quality, potentially due to the lack of data. With this background, this study investigates the relationship using Seoul's existing traffic and air quality monitoring data collected over the period of three years, from 2005 through 2007. In particular, those paired monitoring sites with a distance of less than one kilometer apart were utilized, targeting the emissions of CO, NO, $NO_2$, and $PM_{10}$. As a result, in general the data of two monitoring systems exhibited lower correlations, $NO_2$ showing a relatively higher correlation with traffic volumes than other emissions. In addition, it was found that the degree of correlation can be higher for the data obtained over the morning time period, 6am-9am, and the day after rainy days.

• Journal of Environmental Science International
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• v.15 no.8
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• pp.737-744
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• 2006

Present study was designed to characterize the concentrations of major roadside air pollutants in Daegu and to compare with those of Seoul and Busan. Evaluated were the exceedance frequence of mean concentrations of target compounds(CO, NO$_2$, O$_3$, PM$_{10}$, SO$_2$) and the relationship for time variation. Two air pollution monitoring stations(one roadside station and one residential station) in Daegu were selected for this study. In addition, one roadside monitoring station from each of Seoul and Busan was chosen for the comparison of Daegu monitoring stations. The data analyzed in the current study were collected from 1998 to 2000 by Daegu Regional Environmental Management Office. The roadside concentrations of NO2 and PM to and the exceedance frequency of ambient air standard levels in Daegu were higher than those of Seoul and Busan. Except 03, the roadside concentrations of all target compounds showed following three distinguished patterns; first, possibly due to increased traffic density, the concentrations increased from 0500 to 0900(LST), second, the concentrations decreased from 0900 to 1700(LST) possibly due to the increased wind velocity and decreased traffic density, and finally, increased traffic density, the concentrations increased again from 1700 to 2100(LST). An implication was that major air pollution sources shifted from residential area to road-area during rush hours.

• Electronics and Telecommunications Trends
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• v.36 no.4
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• pp.48-60
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• 2021

Following the global air-traffic market growth outlook, urgency of technical development is needed in responding to changes in the international air-traffic management paradigm and to prepare technology securing and spreading strategies, which are consistent with systematic aviation weather service policies and evolution direction. Although air traffic has decreased significantly due to COVID-19, normalcy is expected from 2024, as announced by IATA. According to the future air transportation market outlook and development trends of related technologies, Korea has established and implementing the next-generation air transportation system construction plan(NARAE) to secure international competitiveness and leadership in the future. Therefore, this paper describes the technical, economic background and requirements of numerical model-based aviation weather R&D projects for successful implementation of domestic NARAE plans and providing aviation safety and air traffic service efficiency. Furthermore, we proposed numerical-model-based technology development content, strategies and detailed load-map.

• Current Optics and Photonics
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• v.2 no.1
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• pp.7-14
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• 2018

As a sophisticated detection technology, LIDAR has been widely employed to probe low-altitude windshear. Due to the drawbacks of the traditional ramp algorithm, the alarm accuracy of the LIDAR has not been satisfactory. Aiming at settling this matter, a novel method is proposed on the basis of improved signal smoothing and second windshear detection, which essentially acts as a combination of ramp algorithm and segmentation approach, involving the human factor as well as signal fluctuations. Experiments on the real and artificial signals verify our approach.

• Journal of Advanced Navigation Technology
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• v.20 no.3
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• pp.203-209
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• 2016

Among the various fields in the communications, navigation, and surveillance/air traffic management (CNS/ATM) scheme, the surveillance field, which includes an automatic dependent surveillance - broadcast (ADS-B) system and a multilateration (MLAT) system, is implemented using satellite and digital communications technology. These systems provide better performance than radar, but still incur position error. To reduce the error, we propose an efficient information fusion method called the reweighted convex combination method for ADS-B and MLAT systems. The reweighted convex combination method improves aircraft tracking performance compared to the original convex combination method by readjusting the weights given to these systems. In this paper, we prove that the reweighted convex combination method always provides better performance than the original convex combination method. Performance from the fusion of ADS-B and MLAT improves an average of 51.51% when compared to the original data.

• Electronics and Telecommunications Trends
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• v.36 no.6
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• pp.55-66
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• 2021

The air traffic industry, one of Korea's major industries, has recently experienced increased demand from overseas air passengers, launched a low-cost airline, and increased special freight transportation capacity. These initiatives have had a positive impact on air traffic (for example, profitability); however, air traffic management has become more complex, which has increased the incidence of aviation accidents and created safety hazards. There is an increasing need to collect and analyze aviation data that can proactively respond to aviation accidents. Concatenation of collected aviation data as big data and the development of artificial intelligence technology are gradually expanding aviation safety event analysis from conventional statistical analysis to machine learning-based analysis. This paper surveys the trends of flight safety event analysis to derive aviation safety risk factors by looking at the types and characteristics of aviation data that can be used to predict accidents related to safety in aviation operations.

• Proceedings of the Safety Management and Science Conference
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• 2008.04a
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• pp.383-387
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• 2008

Nowadays, the tendency of world air cargo is noteworthy and air traffic in terms of cargo throughput will no doubt grow significantly in the new Region, with India and China's booming economy and the upcoming Olympics 2008. For example, in the first 11 months of 2006 cargo traffic was increased by 6.3%. First of all, the market of air cargo in Korea grows very quickly and diversifies. It is an essential factor in the process of development of Northeast-Asia as a hub for Air Cargo logistics. However the process of air cargo in Korea is complex as compared with other north-east asia nations. At the same time, it has many problems and causes inconvenience to owners of freight. This paper investigated the process of air cargo in Korea now and analyzed problems of the process. We emphasize that 4PL is the excellent solution from among many alternatives. It is also worthy of notice that EPCglobal network strengthen the role of 4PL. In conclusion, the 4PL system based on EPCglobal network will result in a good success, so it will raise a prestige of air cargo in Korea to a higher position.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.30 no.3
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• pp.19-27
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• 2022

Urban Air Mobility is expected to resolve some problems in urban transportation such as traffic congestion and air pollution. Various studies for a large-scale commercialization of UAM are being actively conducted. To that end, the UAM Traffic Management system aims at securing a safety and an efficiency of UAM operations. In this study, a risk assessment model is proposed to evaluate the risk of collision between a vehicle and surrounding obstacles. The proposed model is conceived from the past studies for determining a proper separation distance between parallel runways for their independent operations. The model calculates the risk that the surveillance system fails to meet a target level of safety for a given buffer zone size between a designed route and surrounding obstacles. The model is applied to one of the routes proposed in K-UAM roadmap to evaluate its performances.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.8
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• pp.3551-3567
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• 2016

The Low Earth Orbit satellite network has the unique characteristics of the non-uniform and time-variant traffic load distribution, which often causes severe link congestion and thus results in poor performance for delay-sensitive flows, especially when the network is heavily loaded. To solve this problem, a novel adaptive routing algorithm, referred to as the delay-oriented adaptive routing algorithm (DOAR), is proposed. Different from current reactive schemes, DOAR employs Destination-Sequenced Distance-Vector (DSDV) routing algorithm, which is a proactive scheme. DSDV is extended to a multipath QoS version to generate alternative routes in active with real-time delay metric, which leads to two significant advantages. First, the flows can be timely and accurately detected for route adjustment. Second, it enables fast, flexible, and optimized QoS matching between the alternative routes and adjustment requiring flows and meanwhile avoids delay growth caused by increased hop number and diffused congestion range. In addition, a retrospective route adjustment requesting scheme is designed in DOAR to enlarge the alternative routes set in the severe congestion state in a large area. Simulation result suggests that DOAR performs better than typical adaptive routing algorithms in terms of the throughput and the delay in a variety of traffic intensity.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.493-500
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• 2015

The importance of the air and vessel traffic control center is increasing rapidly after the recent accident of 'Sewol ferry'. Aviation, marine, and the logistics sectors are already using monitoring and control technology widely. However, the monitoring and control system for complex and dangerous construction sites operation has yet to be employed. A monitoring/control system is required for effective communication between the control center and the construction equipment fleet at a construction site, and also the exact role that notifies accurate process and identification of hazards on construction sites as needed. Therefore, this paper presents the study about communication between the construction equipment fleet and the control center through the comparison of air traffic, marine, and logistics control systems for the development of construction equipment fleet management system.