• The KIPS Transactions:PartC
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• v.15C no.6
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• pp.573-586
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• 2008

The improved performance and miniaturization of computer and the improvement of wireless communication technology have enabled the emergence of many high quality services. Among them multicast services are receiving much attention and their usage is increasing due to the increase of Internet multimedia services such as video conference, multimedia stream, internet TV, etc. Security plays an important role in mobile multicast services. In this paper, we proposed a secure multicast protocol for a hierarchical micro-mobility environment. The proposed secure multicast protocol provides security services such as authentication, access control, confidentiality and integrity using mechanisms including symmetric/asymmetric key crypto-algorithms and capabilities. To provide forward/backward secrecy and scalability, we used sub-group keys based on the hierarchical micro-mobility environment. With this security services, it is possible to guard against all kinds of security attacks performed by illegal mobile nodes. Attacks executed by internal nodes can be thwarted except those attacks which delete packet or cause network resources to be wasted. We used simulator to measure the performance of proposed protocol. As a result, the simulation showed that effect of these security mechanisms on the multicast protocol was not too high.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.513-516
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• 2003

데이터 패킷 전송을 지원하는 인터넷망에서는 여러 부가 서비스를 제공할 수 있다. 그중 VoIP 는 킬러 에플리케이션이라고 주목받고 있다. 그러나 기존 회선교환망에서 제공하던 음성전송을 패킷망에서 제공할 경우 여러 문제점이 나타난다. 가장 큰 문제점은 서비스 품질면 즉 많은 유저들이 접속함으로써 일어나는 지연이다. 특히 핸드오프가 빈번한 도메인 환경에서는 접속자수가 증가함에 따라 품질저하는 더 크게 일어난다. Mobile IP 는 도메인내의 빈번한 핸드오프상에서는 많은 단점이 있다. HA(Home Agent)로 빈번하게 시그널을 보내기 때문에 많은 제어 메시지 오버헤드가 있으며, 핸드오프중의 많은 패킷 손실이 있다. Micro-mobility 프로토콜은 기존 mobile IP 의 단점을 보완하기 위해 나온 프로토콜이다. 무선 네트웍상의 도메인내에서의 이동성을 지원하며, 손실과 메시지 오버헤드를 줄여 핸드오프시 높은 성능향상을 주고, 효율적인 위치관리를 제공한다. 본 논문은 NS-2(Network Simulator-2)를 이용하여 여러 마이크로 모빌리티 프로토콜하에서 VoIP 를 운용하였을 때, 어느 프로토콜의 확장성이 우수한지를 비교하고, 빈번한 핸드오프시에 어느 프로토콜이 가장 효율적인지를 제시한다.

• Broadcasting and Media Magazine
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• v.24 no.1
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• pp.49-55
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• 2019

최근 수년간 급속도로 발전한 정보통신(ICT) 및 인공지능(AI) 관련 기술은 사회전반에 걸쳐 모든 산업영역에 변화의 바람을 불러일으키고 있다. 교통부문에서도 이러한 기술의 융 복합을 통해 교통체계의 효율성과 안전성을 향상시키기 위한 노력이 자율주행의 기술발전으로 나타나고 있다. 자율주행은 그동안 인간이 운전해오던 자동차 중심의 교통체계에 혁신적인 변화의 동인이 될 것으로 전망된다. 개인 승용차 시장에 자율주행자동차의 등장과 버스, 택시 등 대중교통과 공유교통차량의 대중교통 기능 적용, 그리고 트럭 및 대형버스 등 상용차의 군집주행기술 도입 등 다양한 분야에서 산업화가 진행되고 있는 것이 그 이유다. 이로 인해 시민들의 일상생활에서 가장 중요한 부분을 차지하는 이동성(Mobility)을 제공하는 서비스에 상당한 영향을 줄 것으로 예측되고 있다. 본 고는 자율주행이 가져올 미래 교통체계의 변화로 대변되는 스마트 모빌리티에 대한 기술과 서비스 방향에 대해 진단하고, 효율적인 산업화를 위한 방안을 제시한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.845-847
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• 2022

교통사고의 원인 중 90%는 졸음운전과 같은 운전자의 부주의 때문에 발생하고 있다. 정부에서도 사고로 인한 인명피해 심각성을 인지하고 2019년부터 전방충돌방지 시스템과 차선이탈 경고 장치 등 ADAS(Advanced Driver Assistance Systems)를 의무적으로 적용하도록 규제를 강화하는 추세이다. 충돌사고를 예방하기 위해 본 논문에서는 영상처리를 기반으로 하여 객체 검출, 차간거리 측정, 후미등 검출, 차선 검출 기능을 적용하여 위험한 상황을 감지하고 운전자에게 경고 알림을 제공하는 System을 개발한다. 더 나아가 다양한 모빌리티 서비스에 이를 활용할 수 있는 방안을 제공한다.

• Journal of the Economic Geographical Society of Korea
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• v.25 no.4
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• pp.641-656
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• 2022

This article investigates how Baedal Minjok(BaeMin) has grown to be a dominant mobility platform operator in food delivery sector in South Korea and what roles its brand and branding have played in the process, drawing on the idea of origination. For the purpose, BaeMin is considered as a typical platformized mobility service provider and origination is framed to be an appropriate analytical lens for the business sector. For the origination conception, unlike mainstream neoclassical theory and concepts, is able to deal fairly well with the issues of imperfect competition, imperfect information, and monopolistic brand rent, which are apparent in today's platformized mobility services. Drawing evidence from textual data, empirical analysis pays particular attention to discursive and symbolic dimensions of BaeMin's socio-spatial biography. It is found that national origination underpinning ethnicity comprises an important pillar of BaeMin's brand and branding. Another form of place-based origination is also observed to matter, especially in the varied relation between the mobility service brand's owner and consumers. However, this configuration of BaeMin's brand origination has yet to be fully stabilized, as it has faced with serious challenges including brand vandalism and anti-brand movement especially since its merger to German food delivery platform giant Delivery Hero in 2020. This origination crisis moment appears to be associated with a series of contractions intrinsic to so-called 'platform capitalism'.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.5
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• pp.12-28
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• 2017

The core of the transportation service, so-called Mobility 4.0 is the flexibility of the entire mobility and its implementation. By doing so, the most essential element is to build a platform to link a supply and a demand simultaneously. In other word, a comprehensive analytical framework is to be set with a data repository which can be periodically updated. With such circumstances, the entire trip chain including pedestrian movements is required to be thoroughly investigated and constructed at the viewpoint of the intermodal transit station. A few studies, however, have been attempted. In this study, the comprehensive analytical framework with the integrated mobility at intermodal transit station was proposed, which consisted of the three modules; 1) Data Repository Extracting from Smart Card DB, 2) Framework of Analyzing Integrated Mobility, and 3) Interpretation of the Integrated Mobility with GIS information and the other factors. A case study with the seven railway stations (Sadang, Sindorom, Samseong, Gwanghwanoon, Gangnam, Jamsil, Seoul Nat'l Univ. of Education) was conducted. The stations of the case study were clustered by the three groups with the statistical ground, and it is most likely to understand the effect of a variety of factors and a comprehensive data-driven analyses with the entire trip stages.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1057-1066
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• 2023

Global Navigation Satellite System (GNSS) is one of the core technologies for the 4th Industrial Revolution, and its importance is increasingly highlighted in the next generation communications and smart mobility requiring the accurate location information. As the development of the high-performance/high-precesion GNSS technology makes it possible to obtain the more accurate locations information, the location based products and systems, which provide the high-quality service, are being researched/developed. In this paper, we present the results of a survey on the recent research trends and examples, utilizing GNSS technology in fields of the next generation communications and smart mobility, and analyzes the results.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.3
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• pp.243-249
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• 2020

With the development of the 4th Industry Revolution and the progress of related technologies, people have been using various services in a more convenient way in their daily lives. Among these technologies, the smart mobility is a service that effectively transports people or packets from the origin to the final destination using a variety of methods/vehicles. With respect to the smart mobility technology, the shuttle service is operational at the final destination. The conventional shuttle operation only takes into account the shuttle operability and does not consider the shuttle-passenger efficiency at all by the one-way routing. Therefore, in this paper, we propose the smart shuttle algorithm that can change the routes to efficiently support boarding passengers. Our proposed scheme consists of 3 algorithms: the shuttle operating algorithm, the re-routable shuttle traveling algorithm, and the passenger-riding algorithm. All those 3 algorithms are effectively co-operated and collaborated for better performance. In-depth experiments were conducted to analyze and to show the superior performance, resulting in an average 23.6% reduction of destination-arrival time per passenger, average 10.37% reduction of shuttle-waiting time per passenger, and average 15.38% decrease of shuttle traveling time per hour. This proves that our smart shuttle traveling scheme reveals the whole remarkable performance, effectively using the re-routable characteristics.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.425-431
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• 2021

The purpose of this study is to compare and analyze leading brands of the scooter-sharing system market of Korea, KICKGOING and Lime, in terms of user experience, and to suggest the improvement direction of the applications and scooters of those two services. The assessment was conducted in such a way that the experimental group using scooter-sharing system over a certain frequency would choose the specific service they use most frequently, and complete a questionnaire: based on the reorganized version of the Peter Morville's Honeycomb Model. Based on the results of the experiment, We drew a conclusion that the services need to add navigation features in the application, to provide more simple procedures for reporting breakdown or accident and browsing insurance information, and to improve the user and pedestrian safety levels by gamification, et cetera. We expect this study to help the fast-growing smart mobility market and scooter-sharing systems that represent the market develop into a user-centered way.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.4
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• pp.145-166
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• 2023

The ongoing COVID-19 pandemic has led to a widespread shift towards non-face-to-face/uncrewed services in various sectors of society. Despite this, research on the digital divide has focused predominantly on analyzing various factors, with the notable absence of studies addressing the digital divide. Therefore, study examined the current digital divide in the transportation sector through a survey-based approach. First, a nationwide survey was conducted among adult men and women to assess their digital device usage. Vulnerable groups sesceptible to digital disparities were identified based on factors such as age, education, and income. Second, comparative analysis was conducted to examine the usage patterns of mobile applications related to the transportation sector among the vulnerable and non-vulnerable groups using chi-squared test. These findings suggest that the vulnerable group exhibited lower awareness and preference for mobile applications, a significantly lower frequency of application usage than the non-vulnerable group. Finally, a comparison of the proficiency in utilizing transportation sector mobile applications was conducted, showing that the vulnerable group demonstrated a significantly lower level of proficiency across all aspects of application usage procedures compared to the non-vulnerable group. These survey results provide a valuable foundation for future policy formulation to reduce the digital divide in the transportation sector. By highlighting the current state of digital disparities, the research contributes to developing evidence-based strategies to enhance inclusivity and equal access to digital services in tjwtransportation.