• Journal of KIISE:Computing Practices and Letters
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• v.16 no.12
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• pp.1189-1193
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• 2010

Mobility management is one of the most important research issues in 6LoWPAN, Since the IP-WSN application domain is expanded to real-time applications such as healthcare and surveillance systems, a fast and seamless handover becomes an important criterion in 6LoWPAN. However, a draft of IETF 6LoWPAN WG for mobility support does not decrease handover delay. Although LoWMob supports a fast intra-PAN handover. it can be supported when the infrastructure node has the location information of the other nodes in the mobile node's moving direction. In this paper, we propose a fast and seamless mobility protocol to support intra-PAN handover, named intra-MARIO. In intra-MARIO, a parent node of the mobile node preconfigures its handover to the PAN when the parent node detects its movement, thereby reducing the handover delay. Since intra-MARIO also supports route optimization, the mobile node can communicate with its corresponding nodes through the optimal route. In this paper, we analysis the signaling cost and evaluates that the handover can be completed in 20ms by simulation.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.1
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• pp.23-31
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• 2000

In this paper, we propose an adaptive handover scheme in wireless network. The proposed handover scheme is a hybrid type of virtual path extension and rerouting. The proposed handover scheme chooses the virtual path management scheme according to the service QoS instead of the network topology which is used in the previous hybrid handover schemes. The proposed scheme supports the seamless service and small buffering during virtual path rerouting handover through the multicasting service. To evaluate the performance of the proposed scheme, we computed the number of signaling message used for handover and perform computer simulation. The simulation results show that the proposed scheme provides more efficiency in the handover delay and seamless service than the previous methods.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.229-240
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• 2012

The development of multimedia applications followed by development of high-speed networks has improved the performance of mobile devices with high transfer speed broadband. Mobile internet access has made possible seamless indoor and outdoor mobile multicast services. Multicasting services are used to support efficient group communications. However, mobile multicasting services have two constraints: tunnel convergence and handover latency. Many protocols and handover methods have been proposed to address these problems. The inter-LMA optimized handover model for multicasting services has previously been proposed for PMIPv6-based networks. The proposed model removes the tunnel convergence issue and reduces router processing costs. It also makes possible the performance of fast handover operations with adaptive transmission mechanisms. In addition, the proposed scheme exhibits low packet delivery costs and handover latency in comparison with existing schemes, and ensures fast handover when moving the inter-LMA domain

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.341-344
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• 2005

Mobile IPv6(MIPv6) allows a Mobile Node to talk directly to its peers while retaining the ability to move around and change the currently used IP address. One of the major issues regarding the basic Mobile IPv6 protocol is related to the handover management of a mobile node. This paper proposes efficient approach for adaptation of MIPv6 sing context information in roaming environments. To investigate on a efficient and secure handover procedure, proposed approach method will give us the following advantages: (l)the intention of context is to reduce latency, packet losses and avoid re-initiation of signaling to and from mobile nodes,(2) FMIPv6 aims to reduce handover latency due to IP protocol operations as small as possible in comparison to the inevitable link switching latency.

• Journal of Korea Multimedia Society
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• v.13 no.2
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• pp.205-215
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• 2010

It is necessary to provide a fast and secure handover for seamless real-time multimedia services based on IEEE 802.11. In this paper, we propose FMIPv6 handoff protocol integrating L2/L3 layer based on IEEE 802.11 WLAN environment. In that, we propose a hierarchical key management scheme and authentication mechanism for protecting the handover signaling messages. The number of connections with AAA server is minimized for the fast handover. It is also compared and analyzed the handover cost with previous method.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06d
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• pp.338-343
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• 2007

WCDMA, WLAN, WiBro등과 같은 다양한 이기종 무선 네트워크들이 증가하면서 중첩된 네트워크가 발생하게 되어, 이기종망간의 vertical handover가 증가하게 되고 효율적인 Network 자원관리 필요성이 증가하였다. 이를 위해 특화된 CRRM을 활용한 중첩된 network들의 통합 자원 관리방안을 제안한다. 제안된 방안은 bandwidth와 사용자의 수를 고려하여 bandwidth를 adaptation 시키거나 forced vertical handover를 진행하여 자원을 관리하며, user는 별도의 handover discover 단계를 생략하고 vertical handover를 진행할 수 있으며, Multiple interface를 사용하여 MCoA를 등록하고 다양한 무선네트워크를 이용하여 데이터 전송이 가능해진다.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1098-1100
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• 2002

Inter-RNC(radio network controller) and inter-BSC(base station center) hard handovers involve rerouting. Thus additional delay time for the new bearer setup and reroute determination should be considered. For theses kinds of handovers we propose a new scheme and coined it as ICHP(Inter-Cluster Handover Prediction). When a call approaches a boundary cell of a cluster, ICHP prepares for the handover by performing resource reservations and reroute computation in advance. Performance analysis shows that ICHP provides faster handover and that it lowers the blocking probability.

• Journal of Urban Science
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• v.11 no.2
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• pp.1-8
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• 2022

This study proposed how to identify window defects by using photos uploaded by occupants during the pre-handover inspection of mulch-family housing. A total of 1168 door images were acquired to generate training data and validation data. Subsequently, through the proposed algorithms, every pixel in images labeled a door was binarized using the OTSU threshold, and then dark pixels were identified as defects. Experimental results demonstrated that our computer vision-based defects identification method detects the door with a recall of 57.9%, and door defects with 63.6%. Although it is still a challenge to automatically identify building defects because of the distortion and brightness of photos, this study has the potential to support better defects management. Ultimately, the improved pre-handover inspection may lead to increased customer satisfaction.

• The Journal of the Korea Contents Association
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• v.11 no.9
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• pp.54-62
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• 2011

This paper proposes both global and local mobility management (MM) scheme improved from Multi Protocol Label Switching (MPLS)-based Mobility Management scheme (MPLS-MOB) for seamless service in Next Generation Network (NGN). The proposed scheme adds local MM on the existing MPLS-MOB which supports global MM by processing handover signaling by 2.5 layer switching via Label Switch Path (LSP) of MPLS. We numerically analyze and verify that the proposed scheme has lower handover latency time than the existing ones, such as micro-MM methods using MPLS as well as MIP and an interworking scenario between PMIP and MIP.

• Korean Journal of Construction Engineering and Management
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• v.21 no.4
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• pp.50-61
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• 2020

Safety management has been one of the most critical issues in the construction industry for a long time. Despite continuous efforts, it still shows a higher accident rate than other sectors. To reduce the accident rate, a lot of studies have been performed, mostly focused on contractors or construction phase. Although the initial stage of the construction project has the most significant impact on construction safety and decision-makers at the initial stage play an important role, the safety management system throughout the project entire life-cycle is still insufficient. In addition, although a great deal of information is generated in the construction project and the value is increasing, while it shows an inefficient aspect. This is believed to be due to insufficient information exchange and a lack of standards. In this context, this study aims to analyze the efficiency of information handover in construction safety. For this purpose, a safety management framework for systematically and efficiently managing and utilizing for construction safety information is referred to as 'safety business functions', 'project life-cycle', and 'industrial hierarchy'. The 'safety business functions' are classified into three levels. And then, in order to analyze the efficiency of safety information handover, 'importance of safety business function' and 'efficiency of safety information handover' were evaluated by interviewing with experts. This study can be used as reference data for implementing systematical and efficient safety management, and can also increase construction safety competency.