• Journal of KIISE:Information Networking
• /
• v.37 no.6
• /
• pp.459-465
• /
• 2010

Mobile IPv6(MIPv6) features have several defects such as overloading of nodes, loss of wireless signals, packet loss, movement problem and so forth. Proxy Mobile IPv6 (PMIPv6) got over the limit of MIPv6 problems. MIPv6 features have several defects such as overloading of nodes, loss of wireless signals, packet loss, movement problem and so forth. Research on PMIPv6, which features network-based mobility is actively in progress in order to resolve these issues. PMIPv6 is emerging as a new paradigm that can overcome the limitations of the existing MIPv6. Nevertheless, such PMIPv6 also incurs problems during hand-over. While it offers a solution to node-based problems, it does, too, create long delay times during hand-over. Since MN (Mobile Node) has been sensing its own movements on MIPv6, fast handover can be done easily. However it can't apply fast handover like MIPv6, as it can't apply fast handover like MIPv6 In this paper, the author solved hand-over problem on MIPv6. MAG knows location information of MN and if MN moves into other MAG's area, Location Server gives MN information to the MAG. Therefore, this mechanism makes hand-over process easier.

• 한국정보통신설비학회:학술대회논문집
• /
• 2008.08a
• /
• pp.223-228
• /
• 2008

Recently, various types of wireless access networks, such as WLAN, WiBro and HSDPA, etc, have been successfully deployed by commercial service providers (i.e., KT, KTF). In this situation, there are many efforts to provide high quality of services to guarantee seamless mobility between heterogeneous networks. The IP layer mobility protocols are efficient mechanisms to provide seamless mobility between IP based heterogeneous networks as well as homogeneous networks. However, to apply IP mobility protocols in real heterogeneous networks (i.e., WiBro and HSDPA), we must consider not only the basic features of techniques of wireless access networks (i.e., Data rate, Coverage, Quality of Service) but also the problem of real environment of service provider (i.e., Expanse cost to change the access network). Due to this reason, it is difficult to satisfy required conditions by using only one IP mobility protocol in real heterogeneous networks. Therefore, in this paper, we propose an efficient mobility protocol to solve the complex problems that are occurred in real heterogeneous networks. The proposed protocol, so-called, "Hybrid Mobile IP" tries to provide a synergy effect by integrating Client Mobile IPv4 (CMIPv4) and Proxy Mobile IPv4 (PMIPv4), and using the two mobility protocols selectively according to the situation of real heterogeneous networks.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.4 no.1 s.6
• /
• pp.107-115
• /
• 2005

For effective IP based service implementation on the wireless network environments, wireless network including the ITS network have to support QoS guaranteed protocol such as a RSVP. RSVP is a resource reservation protocol for Internet environment, and its scalability makes easy to implement RSVP over the various IP transport technologies. But for the If based ITS wireless network environment, RSVP is not suitable, since by its path setup procedure characteristic. In the wireless access network for ITS service, when a mobile node moves to other domain it must perform registration procedure. But the registration procedure is time consuming steps, so if a RSVP session was already established in the previous domain, the RSYP session may be disconnected and the time to re establish a new RSVP session is long enough to cause serious packet loss. In this paper, we propose a pre-path reservation mechanism for applying the RSVP in wireless access networks for ITS. In the pre-path reservation mechanism, the resource reservation procedure occurred during a mobile node's handoff time. An access point in wireless access network performs this procedure when the mobile node attempts handoff The access point executes pre-path reservation procedure as a proxy, since the mobile node does not have IP address until the address allocation procedure is finished in a new domain.

• Journal of the Korea Convergence Society
• /
• v.8 no.7
• /
• pp.29-37
• /
• 2017

Compared to the commercial networks, R&E networks have the strength such as flexible network engineering and design. Based on those features of R&E networks, we propose our storage cloud service model which supports general-purpose network users in a central region and experimental network users in distributed regions simultaneously. We prototype our service model utilizing multiple proxy controllers of OpenStack Swift service in order to deploy several regions via experimental backbone networks. Our experiments on the influence of the network latency and the size of data to be transmitted show that the bigger size of data is preferable to the smaller size of data in an experimental backbone network where the network latency increases within 10ms because the rate of throughput decline in the bigger object is comparatively small. It means that our service model is appropriate for experimental network users who directly access the service in order to move intermittently high volume of data as well as normal users in the central region who access the service frequently.

• Journal of Internet Computing and Services
• /
• v.9 no.3
• /
• pp.9-24
• /
• 2008

In this paper, we describes the design of software architecture supporting for healthcare context information service platform based on multi agent in home environment. In this platform, the DOGF supports the execute object and healthcare sensors and device's logical services grouping. JADE framework can support mobility in heterogeneous environment. The multi agents on platform order to support a healthcare context information service it will be able to divide. An agent collects an environment information from distributed devices. Another an agent follows mobile-device specific and it does a different service. And an agent where it manages like this. The mobile-proxy&agent is an interface part between DOGF and JADE, support data interchange or mobility pattern. For DOGF and JADE to provide healthcare context information service, we describes the design of multi agent software platform and multi agent classification by services. Finally we showed the system environments which is physical environments and prototype based on platfonn for healthcare context information services.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.9
• /
• pp.1-10
• /
• 2009

The field of the web service orchestration introduced to generate a valuable service by reusing single services. Recently, it suggests rule-based searching and composition by the AI (Artificial Intelligence) instead of simple searching or orchestration based on the IOPE(Input, Output, Precondition, Effect) to implement the Semantic web as the web service of the next generation. It introduce a AOP programming paradigm from existing object-oriented programming paradigm for more efficient modularization of software. In this paper, we design a dynamic web service orchestration and invocation scheme applying Aspect-Oriented Programming (AOP) and Reflection for Semantic web. The proposed scheme makes use of the Reflection technique to gather dynamically meta data and generates byte code by AOP to compose dynamically web services. As well as, our scheme shows how to execute composed web services through dynamic proxy objects generated by the Reflection. For performance evaluation of the proposed scheme, we experiment on search performance of composed web services with respect to business logic layer and user view layer.

• The KIPS Transactions:PartD
• /
• v.13D no.6 s.109
• /
• pp.839-846
• /
• 2006

Context-aware adaptive service for overcoming the limitations of wireless devices and maintaining adequate service levels in changing environments is becoming an important issue. However, most existing studies concentrate on an adaptation module on the client, proxy, or server. These existing studies thus suffer from the problem of having the workload concentrated on a single system when the number of users increases md, and as a result, increases the response time to a user's request. Therefore, in this paper the adaptation module is dispersed and arranged over the client, proxy, and server. The module monitors the contort of the system and creates a proposition as to the dispersed adaptation system in which the most adequate system for conducting operations. Through this method faster adaptation work will be made possible even when the numbers of users increase, and more stable system operation is made possible as the workload is divided. In order to evaluate the proposed system, a prototype is constructed and dispersed operations are tested using multimedia based learning content, simulating server overload and compared the response times and system stability with the existing server based adaptation method. The effectiveness of the system is confirmed through this results.

• Journal of Distribution Science
• /
• v.14 no.6
• /
• pp.99-106
• /
• 2016

Purpose - The antecedent to the relationship between the effect of the characteristics of strategic alliances and the performance of container liner shipping companies has been investigated in this study as container liner shipping companies' strategic alliances. It affects positively and negatively home, partner, and the third parties' performance in container liner shipping companies. Extensive literature reviews on shipper's strategic alliances reveal that strategic alliances in financial and non-financial performance of container liner shipping companies show the performance such as economic effects, business performance, global supply chain management performance, customer satisfaction, and forward integration and backward integration performance. The purpose of this study is to test empirically that the relationship between the characteristics of strategic alliances and financial and non-financial performance in container liner shipping companies. Structured equation modeling and confirmatory factor analysis were used to test the hypothesis using AMOS statistics program. Most previous researches focused on the relationship between the characteristics of strategic alliances and alliance types. There are few empirical studies that focus on business performance data because it is difficult to collect data in container liner shipping companies. However, this research measures financial and non-financial performance differently compared with the previous researches focusing on the characteristics of strategic alliances and alliance types measurements. Research design, data, and methodology - The conceptual model for the study is based on the studies of Lim (2010), Chen & Zhen (2009), and Wang & Meng (2014). The model is built around the factors of characteristics of strategic alliances and business performance. Cost, marketing, and service factors are regarded as proxy for the characteristics of strategic alliances. The financial and non-financial performance are regarded as proxy for the performance of strategic alliances. Based on the analysis of one hundred cases such as forwarder, shipper, and liner shipping companies, this study uses structural equation modeling to verify the effects of the characteristics of strategic alliances on business performance. Conclusions - This study provides container liner shipping companies to get some policy and practical implications in terms of the characteristics of strategic alliances and business performance. First, the cost factor for alliances characteristics has a positively significant influence on the financial and non-financial performance of strategic alliances. The cost factor relationship between high and low performance group does not have a significant difference on the performance of strategic alliances. Second, the marketing factor of alliances characteristics has a positively significant influence on the financial and non-financial performance of strategic alliances. The high performance group's marketing factor has a great non-financial performance than low performance group, but the low performance group's marketing factor has a grater financial performance than high performance group factor does. Third, the service factor of alliances characteristics has a negative influence on the non-financial performance of strategic alliances. The high performance group's service factor has a great non-financial performance than low performance group. Based on the findings from this study, related implications and future avenues deserve to be discussed.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.8
• /
• pp.1799-1808
• /
• 2010

Recently the increasing collaborative research requires the remote medical and clinical data sharing and access of external institutions. In this paper, an interoperability framework between Grid and PACS using Web services is proposed and implemented in order to provide flexible and efficient medical data management. The Digital Imaging and Communications in Medicine(DICOM) standard defines medical image data exchange and transfer between PACSs and image databases. However, medical data exchange between hospitals is limited within the trusted and static environments. Moreover, DICOM does not provide medical data management and the Grid middleware does not include standard toolkit to access DICOM data. To address this issue, a Web services-based Grid Service Mediator (WGSM) which provides PACS integration and medical image data management is developed. The WGSM consists of several service mediators such as compress mediator, GridFTP mediator, RFT mediator, MyProxy mediator, MDS mediator, and RLS mediator and others. The proposed Web services-based framework provides user authentication and secure data access between PACSs in collaborative environments. In particular, the WGSM allows ordinary users to access remote PACS data in a simple and efficient manner without any the knowledge about underlying Grid middleware.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.24 no.1
• /
• pp.59-74
• /
• 2014

The social network service is a online service letting users express the personality and enhancing the human network. However, these features result in side effects which diffuse personal information and make users access to treacherous information. Therefore, various access control models have been proposed. However, the access control mechanisms which encrypt data are only able to be applied for controlling access from direct node, and the access control mechanisms without data encryption allow service provider to access all the information. Moreover, both mechanisms do not consider dynamic changes in reliability of the users. In this paper, we propose relationship-based dynamic access control model including encryption of sensitive data, which consider the characteristics of SNS and improves the security of SNS.