• Convergence Security Journal
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• v.23 no.3
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• pp.57-64
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• 2023

Due to the COVID-19 pandemic, the broadcasting industry has been greatly affected, to the extent that the footprint of travel programs has disappeared. Although travel programs have been back on the air since 2022, there remains a task of recovering the stagnant desire for travel. Based on a study that travel programs have a positive impact on viewers' travel intentions, this study examined a data service that provides preferred additional information on travel programs, considering the broadcasting environment of satellite broadcasters that transmit multiple travel programs through various channels. Specifically, preferred additional information was investigated for travel programs of various genres and formats, and a feature model based on FODA was designed to be used when the satellite broadcaster decides the data service configuration. In addition, the necessary information for operating the data service was defined based on the feature model, and a method of transmitting it using the DVB-S SI, a domestic satellite broadcasting standard, was devised. The feasibility of this study was also confirmed using a DVB-MHP based data service prototype.

• International Journal of Railway
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• v.6 no.1
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• pp.26-31
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• 2013

Following the success of the KTX (Korea's first high-speed rail system) with a maximum operating speed of 300 km/h opened in 2004, experts in Korea started a research on the development of key technologies for high-speed rail (HSR) with a top speed of 500 km/h. This paper is a preliminary analysis of the research. It first reviews HSR experiences around the world, in terms of traffic and economic impacts of HSR, and presents a preliminary analysis of 500 km/h HSR in Korea. It is estimated that introduction of 500 km/h HSR with a 54% of travel time reduction will increase HSR passengers to about 9.8 million (about 78% of market share) between Seoul and Busan. It is a 23% of growth compared to the base scenario. Along with conventional rail passengers, air passengers are expected to be significantly impacted by the 500 km/h HSR. As a function of HSR travel time, the estimated market shares of both KTX and 500 km/h HSR compared to air are very comparable with previous international experiences. Based on the forecasted traffic, estimated total benefits are $758 million per year.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.2 s.179
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• pp.43-50
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• 2006

Recently, with rapid development of semiconductor and flat panel display, the manufacturing equipments are required to have large travel range, high productivity, and high accuracy. In this paper, an ultra precision decoupled dual servo (DDS) system is proposed to meet these requirements. And a control scheme for the DDS is studied. The proposed DDS consists of a $XY{\Theta}$ fine stage for handling work-pieces precisely and a XY coarse stage for large travel range. The fine stage consists of four voice coil motors (VCM) and air bearing guides. The coarse stage consists of linear motors and air bearing guides. The DDS is mechanically decoupled between coarse stage and fine stage. Therefore, both stages must be controlled independently and the performance of the DDS is mainly determined by the fine stage. For high performance tracking, the controller of fine stage consists of time delay control (TDC) and perturbation observer while the controller of coarse stage is TDC alone. With these individual controllers, two kinds of dual-servo control strategies are suggested: master-slave type and parallel type. By simulations and experiments, the performances of two dual-servo control strategies are compared.

• Korean journal of aerospace and environmental medicine
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• v.30 no.3
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• pp.86-90
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• 2020

Coronavirus disease 2019 (COVID-19) has had a significant impact on our society as a whole. The COVID-19 pandemic is not only a health crisis, it is also an economic, social and humanitarian crisis. Considering the dramatic global economic and social impact that the crisis has engendered, the aviation system is standing on the doorstep of rapid transformation. In particular, the impact on the aviation and travel industries is enormous. Air travel to most countries has been suspended and blocked. Looking at Korea's current situation, COVID-19 has wholly changed the aviation industry. As COVID-19 spreads around the world, countries have come up with aviation safety measures. Infectious disease safety measures were established to protect passengers and crew members, and countries with collapsed medical systems extended the validity period for aviation medical examinations. In Korea, on August 11, the Ministry of Land, Infrastructure and Transport provided guidance on medical measures related to COVID-19 through an official letter of "Notification of cautions for pilots and air traffic control officers (ATCO) when COVID-19 is confirmed". Overseas countries such as the United States and the United Kingdom have announced regulations for aviation medical examination regulations in relation to COVID-19, and have set standards for returning to aviation after COVID-19 is confirmed. In this paper, we would like to investigate the regulations for aviation medical examination related to COVID-19.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.5
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• pp.1123-1133
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• 2015

This study proposed an evaluation method of mobile emissions reduction strategies for air quality management. The proposed method was considered Travel Demand Model (TDM) and Analytic Hierarchy Process (AHP), while an existing method was focused on quantitative factors. AHP of the evaluation indices of mobile emissions reduction strategies show that quantitative evaluation indices such as air pollutants and greenhouse gas reduction are more important than the political evaluation indices (Consistency with an upper plan, Policy applicability, Technical applicability and feasibility) and each weight of air pollutants and greenhouse gas reduction are found to be 0.373 and 0.218. The early scrapping policy of decrepit diesel vehicle is the best policy in the proposal method using TDM and AHP but this result differs from evaluated result by TDM or AHP respectively. These results are limited to the basic assumption and range of reduction scenarios but are expected to contribute to establish more reasonable and effective mobile emission reduction strategies.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.1-14
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• 2022

In this study, in order to analyze the preference for UAM of public transportation users following the introduction of urban air transportation(UAM), A preference consciousness(SP) survey was conducted on 840 users of Incheon public transportation using the Incheon International Airport-Incheon Gil Hospital route, which is the urban air traffic(UAM) demonstration route section. In addition, the means selection model was estimated based on the results of conducting a preference consciousness (SP) survey. As a result of analyzing the time value for travel using the established means selection model, it was found to be 56,428 won/hour, As a result of verifying the elasticity of travel cost (won), in-vehicle time (minutes), and out-of-vehicle time (minutes) in the model, the effect on the urban air traffic (UAM) share in this model was found that travel cost (won), in-vehicle time (minutes), and out-of-vehicle time (minutes) were in order, and the effect was greater when the travel cost (won) decreased than when it increased.

• Journal of Advanced Navigation Technology
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• v.2 no.2
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• pp.143-156
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• 1998

Incheon International Airport(IIA) is planned to open in about two years. Korean government has an ambition to make IIA a major hub airport in Northeast Asia. The most essential and required condition for an airport to be a successful hub airport in a certain region is to have more efficient flight service network than the other airports in the same region. IIA should compete with Japanese airports to be a major hub in Northeast Asia because Japanese government also has a plan to expand greatly the airport capacity in Tokyo area and Kansai airport in Osaka. It is necessary for both IIA and Korean national air carriers to compose efficient flight service network considering hub competition with Japanese major airports. As the liberalization of international air transport industry would give more marketing freedom to airlines, they would plan the flight service network and flight schedule based on market analysis instead of governmental regulations. In the economically liberalized environment, it is very required to analyze air passengers' flight choice behaviour in order to induce other carriers and passengers through IIA's attractive flight service network. Disaggregate model is more appropriate than aggregate model to analyze consumers' behaviour. The information derived from disaggregate choice model of air passengers could be utilized in devising efficient flight network and schedule plan. Value of travel time or trade off ratio between flight frequency and travel time which could be estimated from discrete choice model could be utilized for scheduling an efficient flight plan for airlines and composing efficient flight service network for IIA.

• Journal of the Economic Geographical Society of Korea
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• v.11 no.1
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• pp.59-77
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• 2008

The purpose of this study is to investigate the impact of traffic-related air pollution on the urban population in the Metropolitan Seoul area. In particular, this study analyzes urban population exposure to traffic-related particulate materials(PM). For the purpose, this study examines the relationships between traffic flows and PM concentration levels during the last fifteen years. Traffic volumes have been decreased significantly in recent year in Seoul, however, PM levels have been declined less compare to traffic volumes. It may be related with the rapid growth in the population and vehicle numbers in Gyenggi, the outskirt of Seoul, where several New Towns have been developed in the middle of 1990's. The spatial pattern of commuting has changed, and thus and travel distances and traffic volumes have increased along the main roads connecting CBDs in Seoul and New Towns consisting of large residential apartment complexes. These changes in traffic flows and travel behaviors cause increasing exposure to traffic-related air pollution for urban population over the Metropolitan Seoul area. GIS techniques are applied to analyze the spatial patterns of traffic flows, population distributions, PM distributions, and passenger flows comprehensively. This study also analyzes real time base traffic flow data and passenger flow data obtained from T-card transaction database applying data mining techniques. This study also attempts to develop a space-time model for assessing journey-time exposure to traffic related air pollutants based on travel passenger frequency distribution function. The results of this study can be used for the implications for sustainable transport systems, public health and transportation policy by reducing urban air pollution and road traffics in the Metropolitan Seoul area.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.8
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• pp.1015-1019
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• 2013

To improve the energy efficiency and ride quality of an electric vehicle, it is highly desirable to develop a lightweight suspension system with high travel ratio. Air suspension systems with a rubber tube are often considered optimal for such requirements. In this study, a new lightweight air suspension system with high travel ratio was developed for use in electric vehicles. Furthermore, an FE-based multi-flexible-body dynamics (MFBD) model of the suspension system was developed as a tool for improving the design of an actual suspension system. The MFBD model includes the FE modeling of the rubber tube module as well as other essential parts of the air suspension system. The system parameters for the model were obtained from various experiments. The validity of the developed MFBD model was shown through a comparison between the experimental results and the simulation results.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.1087-1094
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• 2013

This study aims at enhancing the objective estimation of social cost of air quality due to mobile emission. More specifically, it examines the difference between the daily oriented and hourly oriented estimation results of social air quality cost and draws implications from the comparative analysis. The result indicates that the social cost of air quality differs up to approximately 24 times depending on the analysis time period. Moneywise, the difference between daily and hourly assignments amounts to the average of 653.5 billion won whereas only 1% of error occurred in the estimation result based on peak and nonpeak based hourly assignment. This study reaffirms the need for time-based travel demand management for emission reduction, and confirms the feasibility of emission estimation by travel demand forecasting method over the conventional method employed by the CAPSS.