• Journal of the Korean Regional Science Association
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• v.33 no.3
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• pp.101-113
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• 2017

This study examines the mobility of the disadvantaged population groups in terms of public transportation using the 2014 smart card data in Seoul, Korea. Particularly, we focus on the disadvantaged population such as senior group, junior group, and low-income population group. Based on the spatial distributions of public transportation mobility levels and the disadvantaged population groups, we identify specific areas where public transportation service should be improved for the disadvantaged population. As a result, we identify 15 administrative-dongs where the ratio of the disadvantaged population is high while the mobility index of public transit is low. The main contributions of this study are as follows. First, we use the smart card data which contains the information of actual trip made by individuals and develop the evaluation process of urban mobility for the disadvantaged population groups. Second, we identify the specific areas where public transportation service should be improved for the different group of the disadvantaged population. Lastly, we discuss policy implications to improve the urban mobility of the disadvantaged population.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.107-118
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• 2022

As connected and automated driving(CAD) technology is entering its commercialization stage, service platforms providing CAD-based mobility services have increased these days. However, CAD-baded mobility services with these platforms need more consideration for the demand for mobility services when determining target areas for CAD-based mobility services because current CAB-based mobility design focus on driving performance and driving stability. For a more efficient design of CAD-based mobility services, we analyzed the applicability for the introduction of CAD-based mobility services in terms of driving difficulty of CAD and demand patterns of current non-CAD based-mobility services, e.g., taxi, demand-responsive transit(DRT), and special transportation systems(STS). In addition, for the spatial analysis of the applicability of the CAD-based mobility service, we propose the Index for Autonomous Driving Applicability (IADA) and analyze the characteristics of the spatial distribution of IADA from the network perspective. The analysis results show that the applicability of CAD-based mobility services depends more on the demand patterns than the driving difficulty of CAV. In particular, the results show that the concentration pattern of demand in a specific road link is more important than the size of demand. As a result, STS service shows higher applicability compared to other mobility services, even though the size of demand for this mobility service is relatively small.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.315-323
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• 2015

Nowadays, it is expected that mobility loads such as electric railways and electric vehicles will be penetrated gradually and affect on the power system stability by their load characteristics. Various researches have been carried out about electric vehicles for the recent decade though the load of electric railway could be forecasted because of the specified path and timetable, is a field with a long historic background. Some precise 5th polynomial equations are required to analyze the power system stability considering mobility load to be increased in the immediate future while the electric railway dispatching simulator uses load models with constant power and constant impedance for the system analysis. In this paper, seasonal urban railway load models are established as the form of 5th polynomial equations and substation load modeling methods are proposed merging railway station load models and general load models. Additionally, load management effects by the load modeling are confirmed through the case studies, in which seasonal load models are developed for Seoul Subway Line No. 2, Gyeongui Line and Airport Railroad and the substation load change is analyzed according to the railway load change.

• Journal of Korean Society of Transportation
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• v.35 no.1
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• pp.50-62
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• 2017

As the use of private cars increases along with the technological advancement in the automobile industries and their capabilities to supply, a wide range of issues are followed including the increase in traffic congestion costs, pavement damages and more. In spite of consistent effort to resolve such urban traffic problems, the modal share rate of private cars continuously increases, thus it is becoming more important to explore the ways to enable drivers to take reasonable measures, in self-motivated manner, by taking part of the transportation demand management policy rather than to rely on the strict enforcement of control policy. Considering that the urban transportation infrastructures are in much better shape than before, it is necessary to implement Mobility Management (MM) that induces reasonable usage of private cars by promoting the change in one's consciousness and behavior through communication. Hence, the research studies the factors that influence the mobility through the survey targeting the citizens of Busan on their awareness on the former transportation demand management policy, to explore the ways to motivate the citizens' involvement in reducing the use of private cars as a measure of Mobility Management.

• Journal of Communications and Networks
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• v.16 no.6
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• pp.645-655
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• 2014

Latency, an identified element of Internet protocol (IP) mobility protocol execution, can reduce handover performance in mobile networks. Although the performance can be improved by applying an effective network-based IP mobility scheme in place of the traditional host-based alternatives, the existing inter-domain extensions of network-based IP mobility continue to suffer from an extended handover latency. This paper proposes a new inter-domain network-based IP mobility scheme based on node movement prediction. The proposed scheme accelerates the handover by preparing the future domain of the mobile node in a proactive manner. Analytical and simulation-based evaluations confirm improved performance of the proposed scheme in terms of handover latency and packet loss compared with existing schemes.

• Journal of Korean Society of Transportation
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• v.32 no.6
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• pp.628-637
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• 2014

The purpose of this study is to investigate the actual conditions of the mobility convenience facilities for pedestrians and their perception of the facilities, and thereby provide fundamental material necessary to establish a strategy of improving mobility convenience facilities. This study tried to analyze the characteristics of the mobility convenience facilities for pedestrians. Based on previous studies and "Report of Mobility Facilities of the Mobility Handicapped", this study first chose the evaluation items related to mobility convenience facilities, and then conducted a questionnaire survey and Importance-Performance Analysis (IPA). According to the study results, first, the item that needs intensive improvement was sidewalks, and the detailed indicators for sidewalks were walking safety, convenient facilities for the disabled, and pavement in order. Secondly, the items that need to be maintained were bus and crossroad. Thirdly, the low-ranking items were under-passageway and pedestrian overpass. And lastly, the items that need to be controlled were facilities for passenger terminals and bus terminals. Based on the comprehensive IPA result, this researcher judged the actual use conditions of the mobility convenience facilities in Buyeo-gun, Chungcheongnamdo. Therefore, it was found that it would be urgent to improve the direct walking environment on sidewalks. In this aspect, for future policy decision and facility maintenance, it is desirable to put the item in priority in terms of investment and come up with an improvement strategy.

• Journal of Advanced Navigation Technology
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• v.27 no.6
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• pp.710-715
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• 2023

Urbanization brings many challenges such as traffic, housing, and environment. To solve these problems, researchers are working on new transportation systems like urban air mobility (UAM). UAM aircraft should fly safely without burdening the existing air traffic system in the early stage of low-density operation. The airspace should also be managed and operated efficiently. Therefore it is important to make urban air traffic predictable by using corridors and collecting data on low-density operations in the early stage. For this purpose various simulations are needed before operation to create scenarios that estimate potential collisions between UAM aircraft and to evaluate the risks of aircraft spacing, loss of separation (LoS), and near mid air collision (NMAC). This paper focuses on identifying the requirements and considerations for setting separation standards for urban air traffic based on the results of studies.

• Journal of Aerospace System Engineering
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• v.18 no.1
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• pp.29-36
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• 2024

Recently, the concept of Urban Air Mobility (UAM) has expanded to Advanced Air Mobility (AAM). A tilt rotor type of vertical take-off and landing aircraft has been actively studied and developed. A tilt-rotor aircraft can perform a transition flight between vertical and horizontal flights. A blade pitch angle control system can be used for flight stability during transition flight time. In addition, Individual Blade Control (IBC) can reduce noise and vibration generated in transition flight. This paper proposed Disturbance Observer Based Control (DOBC) and Time Delay Control (TDC) for individual blade control of an Electro-Mechanical Actuator (EMA) based blade pitch angle control system. To compare and analyze proposed controllers, numerical simulations were conducted with DOBC and TDC.

• Journal of the Korean housing association
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• v.25 no.4
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• pp.93-100
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• 2014

The purpose of this study, analyzing the primary factors for residential mobility and housing preference of Daegu citizens, is to provide a basic data for future housing policies. The results are as follows: First, 32.1% of Daegu citizens have intention of residential mobility. Especially the residents in central (50.0%), southern (59.0%) and western Daegu showed more intention than those in other districts. Second, we used the GLMM (Generalized Linear Mixed Models) to analyze the main factors for residential mobility. The results are as follows; 1) the residents who have lower housing satisfaction with the type of housing, parking, and educational environment, 2) those who are male and younger, 3) those who live in rented house have more intention of housing mobility. Third, based on the analysis on the preference change of the type of housing, the preference of the apartments is getting higher, while that of the detached houses is getting lower (past: 40.1%${\rightarrow}$present: 54.8%${\rightarrow}$future: 66.7%). 28.8% of the respondents (444) expressed intention to live in the public rental houses, in case they are provided in the areas they are moving to. Fourth, when we analyzed the size of the houses they actually lived in and that of the houses they prefer to live in case of moving, we found that in general they tend to move in smaller housing than in the past. The results of the analysis showed that in order to minimize the possible moving away from the current residential areas due to the dissatisfaction with the housing environment, in the first place the improvement in the quality of the houses, parking and education environment is needed.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.1
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• pp.77-86
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• 2024

Urban Air Mobility (UAM) is considered the future of transportation, offering solutions to urban challenges and reducing environmental issues through the use of electric power and leveraging the sky as a new transportation corridor. UAM has diverse applications, including passenger and goods transportation, emergency rescue operations, patient transfers, and urban tourism. Furthermore, it is poised to revolutionize the transportation landscape, impacting existing infrastructures such as roads and parking lots, along with autonomous vehicles. The UAM industry is anticipated to exert a significant impact on various sectors, including airframe manufacturing, the development of new materials (e.g., fuel cells and batteries), and even the defense industry, resulting in substantial economic benefits. Consequently, conducting proactive research and setting industry standards for UAM takeoff and landing infrastructure is crucial for securing market leadership. In this regard, the case of Pontoise-Cormeiles, France, stands out as it achieved the world's inaugural successful demonstration of a vertiport before the 2024 Olympics. This achievement has significant implications for our preparations for the commercialization of UAMs. Thus, a detailed review of the French vertiport construction case in this study will serve as a foundation for guiding the planning and operation of UAMs in South Korea, particularly in anticipation of upcoming demonstration tests.