• Journal of Digital Convergence
• /
• v.17 no.7
• /
• pp.351-357
• /
• 2019

A number of case studies and type analyzes have been conducted on mobility platform services that are rapidly evolving around the world. However, since the actual user experience is important for the development of the mobility service, research on the user side is needed. In the mobility platform service, only the car-hailing was used, and the preference factors were analyzed through the questionnaire in seven aspects of the user experience. Studies have shown significant differences according to gender. While the safety of the woman, the comfort and the kindness of the vehicle have a great influence on the satisfaction, the male affirms that the familiarity is the factor affecting the satisfaction. This study focused on the customer experience as a real user and identified key factors of selecting mobility platform service, so it is expected that it will contribute to the development of mobility platform service in the future.

• Journal of the Korean Society for Precision Engineering
• /
• v.30 no.7
• /
• pp.725-732
• /
• 2013

This paper presents a torque distribution algorithm for improving the stability and mobility of a wall-climbing robot platform. During ascent, the pitch moment caused by the payload or external disturbances separates the robot's triangular tracks from the wall, significantly deteriorating its stability. Moreover, the reaction forces stemming from the increase in the pulling force may degrade the robot's mobility. Thus, it is very important to minimize the reaction forces acting on the triangular tracks, as well as the fluctuations in the pulling force, during the climb. Through dynamic modeling of the proposed robot platform, we demonstrated the dependence of the robot's stability and mobility on the torque distribution of the triangular tracks. Extensive simulations using different climbing speeds were used to significantly improve the stability and mobility of the proposed robot platform.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.16 no.2
• /
• pp.153-160
• /
• 2017

Recently, the demand has continued to increase for higher data rates and improved multimedia services through wireless internet access. In order to increase the data rate and link reliability, 3GPP LTE/A and IEEE 802.16e/m WiMAX systems incorporate MIMO transmission schemes. Since the hardware complexity increases with the number of transmit data streams and mobile devices have limited physical dimensions, an multiple input multiple output (MIMO) ystem with two antennas at both the transmitter and the receiver ($2{\times}2$) is considered to be a possible solution for mobile devices. In this paper, a low-complexity soft output MIMO symbol detector based on Modified-SQRD is proposed for mobile devices with two transmit and two receive antennas.

• Journal of Advanced Navigation Technology
• /
• v.22 no.5
• /
• pp.391-399
• /
• 2018

V2X communication is a technology in which a vehicle exchanges information with various entities such as other vehicles, infrastructure, networks, pedestrians, etc. through a wired or wireless network. Recently, V2X communication technology has been steadily developed and recently it has played an important role in autonomous cooperation driving technology combined with autonomous vehicle technology. Autonomous vehicles can utilize the external information received via V2X communication to extend the recognition range of existing sensors and to support more safe and natural autonomous driving. In order to operate these autonomous cooperative vehicles on public roads, the security and reliability of autonomous V2X communication should be verified in advance. In this paper, we present test scenarios and test procedures of secure V2X communication for cooperative automated driving and present verification results.

• Journal of IKEEE
• /
• v.28 no.3
• /
• pp.310-320
• /
• 2024

This article describes the 5G-NR-V2X system and its communication performance methodology. We present a system that can develop and verify the performance of self-driving services in a real road test environment using OBU and RSU for 5G-NR-V2X communication (level 4 or higher). This system ensures ultra-high speed (150Mbps or more), ultra-low latency (3ms or less), and high reliability (99.99 percent) in communication robustness, even under malicious conditions. The 5G-NR-V2X system and performance analysis method proposed in this paper are anticipated to aid in the development of V2X communication technologies that are ultrafast, ultralow-delay, and high-confidence. In addition, it is expected that the services validated by the suggested performance analysis technique will enhance technological competitiveness in the road, transportation, logistics, and commerce industries.

• 한국정보통신설비학회:학술대회논문집
• /
• 2008.08a
• /
• pp.304-308
• /
• 2008

The standardization for Seamless IP Mobility between heterogeneous networks is being progressed according to each specific purpose of the organizations such as ITU-T (International Telecommunications Union - Telecommunication), 3GPP(3rd Generation Partnership Project), IETF(Internet Engineering Task Force), and IEEE(Institute of Electrical and Electronics Engineers). [1] Specially VCC (Voice Call Continuity) for seamless voice continuity between heterogeneous networks using IMS (IP Multimedia Subsystem) of the next generation platform is being introduced into a few companies, and also MIH (Media Independent Handover) and MIP (Mobile IP) for IP mobility between heterogeneous networks are being customized by their internal situation. This article describes the idea to support IP Mobility between heterogeneous networks in the network which IMS platform is deployed and only supports the mobility for the voice by the type of AS (Application Server).

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.9 no.3
• /
• pp.206-212
• /
• 2009

This paper presents an optimized integrated task planning and control approach for manipulating a nonholonomic robot by mobile manipulators. Then, we derive a kinematics model and a mobility of the mobile manipulator(M2) platform considering it as the combined system of the manipulator and the mobile robot. to improve task execution efficiency utilizing the redundancy, optimal trajectory of the mobile manipulator(M2) platform are maintained while it is moving to a new task point. A cost function for optimality can be defined as a combination of the square errors of the desired and actual configurations of the mobile robot and of the task robot. In the combination of the two square errors, a newly defined mobility of a mobile robot is utilized as a weighting index. With the aid of the gradient method, the cost function is minimized, so the path trajectory that the M2 platform generates is optimized. The simulation results of the 2 ink planar nonholonomic M2 platform are given to show the effectiveness of the proposed algorithm.

• Information Systems Review
• /
• v.23 no.4
• /
• pp.103-125
• /
• 2021

Mobility services are rapidly developing along with information and communication technology (ICT) innovation. Recently, the on-demand mobility platform market is growing, and an environment is provided in which users can call services more conveniently and check the connection status in real time using smartphones. This study investigates the current status of users' perceptions and experiences of car-hailing mobility services such as KAKAO Taxi and UT Taxi, and it analyzes the factors affecting the intention to continuously use the car-hailing service, focusing on environmental and instrumental benefits and trust in driver and platform. In particular, this study examines whether the significance of the relationship between influencing factors and continuous use intention could vary depending on the degree of innovativeness and ICT utilization. The results of this study showed that perceived benefits (environmental benefits and convenience and economic instrumental benefits) and trust in driver had significant effects on increasing trust in platform. It was analyzed that the higher the trust in platform, the higher the intention to continuously use the car-hailing service. Furthermore, the influence of perceived environmental benefits and economic benefits on the trust in platform was different depending on the degree of individual innovativeness, and the influence of convenience and economic benefits on the trust in platform varied depending on the degree of ICT utilization. Referring to the results of this study, mobility service providers can better understand the current status of users' perceptions and trust for car-hailing services, and implement service promotion strategies suitable for individual characteristics.

• Journal of the Korea Society for Simulation
• /
• v.14 no.4
• /
• pp.77-86
• /
• 2005

[ $IP^2$ ] (IP-based IMT Network Platform) is a ubiquitous platform supporting mobility using two step If address IPha (IP host address) and IPra (IP routing address) - in a backbone network. MN (Mobile Node) in $IP^2$ maintains either Active or Dormant state, which is transferred to Active state through Paging process when communication is required. In this paper, we proposed a Paging method using proxy to resolve the problem of the conventional Paging method which transmits the Paging messages to all cells in LA (Location Area) resulting in the excessive use of network resources. Performanceevaluation of the proposed method using NS-2 showed that the usage of network resources becomes more efficient by reducing paging loads, especially under the condition of increased nodes.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2005.11a
• /
• pp.3-7
• /
• 2005

The structure of $IP^2$(IP based-IMT Network Platform) as ubiquitous platform is three-layered model : Middleware including NCPF(Network Control Platform) and SSPF(Service Support Platform), IP-BB(IP-Backbone), Access network including Sensor network. A mobility management(MM) architecture in NCPF is proposed for $IP^2$. It manages routing information and location information separately. The existing method of multicast control in $IP^2$ is Remote Subscription. But Remote Subscription has problem that should be reconstructed whole Multicast tree when sender moves. To solve this problem, we propose a way to put Multicast Manager in NCPF.