• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.4
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• pp.929-940
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• 2016

The IMO e-navigation strategy has requested a communication infrastructure providing authorized seamless information transfer between stakeholders. The Maritime Cloud is the term used to describe the concept of an infrastructure that support authorized, seamless information transfer, adding those elements, that are necessary to support the e-navigation domain. It is necessary to consider the study on maritime cloud security, but the study is still an early stage. In this paper, we propose a secure synchronization method for the maritime cloud services. The proposed method can be synchronize between the vessel based on the SH-Tree, and it has the advantage that there is no exposure information in the synchronization process.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.2
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• pp.637-658
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• 2015

The development of multimedia applications has followed the development of high-speed networks. By improving the performance of mobile devices, it is possible to provide high-transfer-speed broadband and seamless mobile multicasting services between indoor and outdoor environments. Multicasting services support efficient group communications. However, mobile multicasting services have two constraints: tunnel convergence and handoff latency. In order to solve these problems, many protocols and handoff methods have been studied. In this paper, we propose inter local mobility anchor (inter-LMA) optimized handoff model for mobile multicasting services in proxy mobility IPv6 based (PMIPv6-based) networks. The proposed model removes the tunnel convergence issue and reduces the router processing costs. Further, it the proposed model allows for the execution of fast handoff operations with adaptive transmission mechanisms. In addition, the proposed scheme exhibits low packet delivery costs and handoff latency in comparison with existing schemes and ensures fast handoff when moving the inter-LMA domain.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.4
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• pp.302-311
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• 2016

This paper proposes a hybrid ESS that integrates an energy storage system (ESS) with an uninterruptible power supply (UPS). The hybrid ESS has a demand management and emergency power supply function while increasing the battery utilization of the UPS, which has just been used in a power failure. In addition to the critical load, the proposed system augments the capacity of emergency generation using an additional load, which has voltage and frequency-dependent characteristics to the grid side. The control algorithm of the AC-DC converter and bidirectional DC-DC converter is proposed for demand management and emergency power supply. Furthermore, seamless and autonomous transfer methods to alleviate the transient during mode transfer are proposed. To validate the proposed control scheme, experimental results from a 5 kW prototype are provided.

• KIISE Transactions on Computing Practices
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• v.22 no.7
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• pp.310-314
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• 2016

Currently, several research studies are looking to improve the quality of DASH (Dynamic Adaptive Streaming over HTTP) based live streaming services. However, conventional DASH based streaming schemes cannot provide seamless playback while maintaining the low buffering and it adversely affects the QoE (Quality of Experience). To address this problem, we propose the QoE driven segment scheduling scheme. The proposed scheme adaptively schedules the segment request message according to the time and variation of segment fetching. Simulation results indicate that the proposed scheme improves the QoE of live streaming service by maintaining the low buffering delay and reducing the buffer underflow events.

• Journal of the Korea Society of Computer and Information
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• v.9 no.3
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• pp.171-175
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• 2004

This paper proposes a seamless handoff scheme that enables a mobile node to continue a session when moving to an overlapping area. During handoff due to the weakness of signaling, mobile node makes new Care-of Addresses using signals received from access router when MN reaches the edge of its area in addition to its current CoA, and it sends temporary binding update messages to Mobility Anchor Point which manage the area covering MN. MAP receives that binding update messages from MN, and temporarily stores new binding informations from them to its binding cache besides existing binding information for MN. This scheme ensures a seamlessly handoff using multicasting until MN enter a new access router area and sends a confirmed binding update message to MAP.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.4
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• pp.399-422
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• 2009

Although current wireless mesh network (WMN) applications experience a perceptually uninterrupted hand-off, their throughput after the hand-off event may be significantly degraded due to the low available bandwidth of the mobile client's new master. In this paper, we propose a novel mobility management scheme for 802.11-based WMNs that enables both seamless hand-off for transparent communications, and bandwidth awareness for stable application performance after the hand-off process. To facilitate this, we (i) present a new buffer moment in support of the fast Layer-2 hand-off mechanism to cut the packet loss incurred in the hand-off process to zero and (ii) design a dynamic admission control to grant joining accepts to mesh clients. We evaluate the benefits and drawbacks of the proposal for both UDP and TCP traffic, as well as the fairness of the proposal. Our results show that the new scheme can not only minimize hand-off latency, but also maintain the current application rates of roaming users by choosing an appropriate new master for joining.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.4
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• pp.455-468
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• 2014

This paper presents seamless hand off implementation suggesting algorithm and Measuring /testing at the tunnel environment in order to derive the ideal value of wireless data transmission in RF-CBTC train control system modeled by Shinbundang Operation System. In addition, it proposes the ideal value(-57dB) for reducing the re-transmission or frequency interference rate and demonstrates frequency optimization which enables highly reliable data communication in Train control system using wireless communications. Based on these result, Shinbundang phase 2 plan to apply to this system.

• Journal of Intelligence and Information Systems
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• v.12 no.1
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• pp.163-175
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• 2006

This paper provides a corporation's marketing strategy under a ubiquitous computing environment: a WOM(word-of-mouth) marketing using RFID(Radio Frequency Identification) technology and a business model which facilitates the word-of-mouth marketing. To this end, we examine the word-of-mouth communication effects on consumers' life, changes in corporations' attitude toward word-of-mouth marketing, and the difficulties that corporations have in conducting word-of-mouth marketing. The business model this paper suggests makes seamless business-to-consumer and consumer-to-consumer networking possible using the RFID technology and facilitates the word-of-mouth marketing through incentive system of each economic player.

• ETRI Journal
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• v.32 no.5
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• pp.665-675
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• 2010

Recent research on mobile Internet protocol television and digital right management (DRM) interconnections has focused on multimedia technologies designed to enhance content scalability and adaptive content distribution. However, due to the architectural and scalable limitations, recent systems are not flexible and securable with respect to their adaptive content distribution and protective policy management. Therefore, we propose a content protective multi-agent platform that provides secure multimedia services, correlation management, pattern-based management, and multi-source multi-use (MsMu)-based services. Our architecture, supported by DRM, lets us create a rich set of MsMu-based content protection and seamless multimedia services through the extension of one source multi-use (OsMu)-based content services. We have verified our platform, which provides scalable and securable services with a 17% lower service response time by using a testbed.

• Journal of Information Processing Systems
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• v.13 no.2
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• pp.236-255
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• 2017

The rapid growth of smart devices demands an enhanced throughput for network connection sustainability during mobility. However, traditional wireless network architecture suffers from mobility management issues. In order to resolve the traditional mobility management issues, we propose a novel architecture for future wireless access network based on software-defined network (SDN) by using the advantage of network function virtualization (NFV). In this paper, network selection approach (NSA) has been introduced for mobility management that comprises of acquiring the information of the underlying networking devices through the OpenFlow controller, percepts the current network behavior and later the selection of an appropriate action or network. Furthermore, mobility-related scenarios and use cases to analyze the implementation aspects of the proposed architecture are provided. The simulation results confirm that the proposed scenarios have obtained a seamless mobility with enhanced throughput at minimum packet loss as compared to the existing IEEE 802.11 wireless network.