• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1146-1154
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• 2010

A virtual machine lease service in the cloud computing environment has been implemented using the open source cloud computing platform, OpenNebula. In addition, a web-based cloud user interface is developed for both convenient resource management and efficient service access. The present virtual machine allocation scheme adopted in OpenNebula has performance reduction problem because of not considering CPU allocation scheduler of the virtualization software. In order to address this problem we have considered both the priority of the idle CPU resources of the cluster and credit scheduler of Xen, which resulted in performance improvement of the OpenNebula virtual machine scheduler. The experimental results showed that the proposed allocation scheme provided more virtual machine creations and more CPU resource allocations for cloud service.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.12a
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• pp.669-685
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• 2003

Nowadays mobile phones and PDAs are part and parcel of our lives. By carrying a portable mobile device with us all the time we are already living in partial Pervasive Computing Environment (PCE) that is waiting to be exploited very soon. One of the advantages of pervasive computing is that it strongly supports the deployment of Location-Based Service(s) (LBSs). In PCE, there would be many competitive service providers (SPs) trying to sell different or similar LBSs to users. In order to reserve a particular service, it becomes very difficult for a low-computing and resource-poor mobile device to handle many such SPs at a time, and to identify and securely communicate with only genuine ones. Our paper establishes a convincing trust model through which secure job delegation is accomplished. Secure Job delegation and cost effective cryptographic techniques largely help in reducing the burden on the mobile device to securely communicate with trusted SPs. Our protocol also provides users privacy protection, replay protection, entity authentication, and message authentication, integrity, and confidentiality. This paper explains our protocol by suggesting one of the LBSs namely“Secure Automated Taxi Calling Service”.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.2
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• pp.239-251
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• 2014

The personal cloud is a service which approaches the personal contents scattering to all terminals and online space at the personal information-oriented age in which the person's digital device including the Smart-phone, MID, PC, IPTV and etc, increases and the personal online service including the blog, E-mail, UCC, social network service and ect, rapidly increasing for the cloud computing regardless of the terminal anywhere independently and can provide the high vale added personalization service through the analysis of the contents and processing. The future of the personal cloud market is prospected through the service and technology which enhances the understanding about the cloud computing, that is the next generation IT paradigm which the world IT companies pay attention to, and is provided and business strategy analysis of the security and normalizing and related companies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.12
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• pp.4364-4384
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• 2021

The dynamic network state and the mobility of the terminals make the service function chain (SFC) orchestration mechanisms based on static and deterministic assumptions hard to be applied in SDN/NFV mobile edge computing networks. Designing dynamic and online SFC orchestration mechanism can greatly improve the execution efficiency of compute-intensive and resource-hungry applications in mobile edge computing networks. In order to increase the overall profit of service provider and reduce the resource cost, the system running time is divided into a sequence of time slots and a dynamic orchestration scheme based on an improved column generation algorithm is proposed in each slot. Firstly, the SFC dynamic orchestration problem is formulated as an integer linear programming (ILP) model based on layered graph. Then, in order to reduce the computation costs, a column generation model is used to simplify the ILP model. Finally, a two-stage heuristic algorithm based on greedy strategy is proposed. Four metrics are defined and the performance of the proposed algorithm is evaluated based on simulation. The results show that our proposal significantly provides more than 30% reduction of run time and about 12% improvement in service deployment success ratio compared to the Viterbi algorithm based mechanism.

• Journal of Information Processing Systems
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• v.10 no.3
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• pp.365-383
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• 2014

Service-oriented computing offers efficient solutions for executing complex applications in an acceptable amount of time. These solutions provide important computing and storage resources, but they are too difficult for individual users to handle. In fact, Service-oriented architectures are usually sophisticated in terms of design, specifications, and deployment. On the other hand, workflow management systems provide frameworks that help users to manage cooperative and interdependent processes in a convivial manner. In this paper, we propose a workflow-based approach to fully take advantage of new service-oriented architectures that take the users' skills and the internal complexity of their applications into account. To get to this point, we defined a novel framework named JASMIN, which is responsible for managing service-oriented workflows on distributed systems. JASMIN has two main components: unified modeling language (UML) to specify workflow models and business process execution language (BPEL) to generate and compose Web services. In order to cover both workflow and service concepts, we describe in this paper a refinement of UML activity diagrams and present a set of rules for mapping UML activity diagrams into BPEL specifications.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.23 no.3
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• pp.57-84
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• 2012

With the advent of Big data era unleashed by tremendous increase of structured and unstructured data, a library needs an effective method to store, manage and preserve various information resources. Also, needs of collaboration of libraries are continuously increased in digital environment. As an effective method to handle the changes and challenges in libraries, interest on cloud computing is growing more and more. This study aims to propose a method to introduce cloud computing in libraries. To achieve the goals, this study performed the literature review to analyze problems of existing library systems. Also, this study proposed considerations, expectations, service scenario, phased strategy to introduce cloud computing in libraries. Based on the results extracted from cases that libraries have introduced cloud computing-based systems, this study proposed introduction strategy and specific applying areas in library works as considered features of cloud computing models. The proposed phased strategy and service scenario may reduce time and effort in the process of introduction of cloud computing and maximize the effect of cloud computing.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.281-283
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• 2009

Forming Community is important to manage and provide the service in Ubiquitous Environments including embedded tiny computers. Community Computing is that members constitute the community and cooperate. A mutual exclusion problem occurs when many processors try to use one resource and race condition happens. In the expanded concept, a group mutual exclusion problem is that processors in the same group can share the resource but processors in different groups cannot share. As mutual exclusion problems might be in community computing environments, we propose algorithm which improves the execution speed using RMS (resource management service). In this paper describes proposed algorithm and proves its performance by experiments, comparing proposed algorithm with previous method using quorum-based algorithm.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.60-63
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• 2011

인터넷은 단순한 정보습득을 위한 공간을 넘어 사람들이 모여 교류하는 '소통의 장'으로서 역할을 하고 있다. 최근에는 타인과 끊임없이 대화를 나누고 소통하려는 인간의 기본 욕구를 반영한 서비스인 SNS(Social Network Service)가 전 세계의 주목을 받고 있다. 또한 LBS(Location-Based Service)는 GPS, Wi-Fi를 통한 위치정보를 활용하여 업무생산성 개선 및 다양한 생활 편의를 제공하는 서비스이다. 본 논문에서는 안드로이드 OS를 기반으로 LBS와 SNS를 통합한 어플리케이션을 제안한다. 개인용 모바일 정보기기인 스마트폰을 활용하여, 위치정보에 이용자 정보, SNS를 결합하여 서비스를 고도화 한다. 지인들의 위치를 기반으로 현재 상태, 트윗(Twit)을 통해 정보의 공유 및 활용을 극대화 할 수 있다. 이를 통해 사용자들이 적극적이고 용이하게 온라인 Identity를 표현하는 것을 목적으로 본 시스템을 제안한다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.719-724
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• 2007

Many engineering problems often require the large amount of computing resources for iterative simulations of problems treating many parameters and input files. In order to overcome the situation, this paper proposes an e-Science based computational system. The system exploits the Grid computing technology to establish an integrated web service environment which supports distributed high throughput computational simulations and remote executions. The proposed system provides an easy-to-use parametric study service where a computational service includes real time monitoring. To verify usability of the proposed system, two kinds of applications were introduced. The first application is an Aerospace Integrated Research System (e-AIRS). The e-AIRS adapts the proposed computational system to solve CFD problems. The second one is design and optimization of protein 3-dimensional structures.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2004.11a
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• pp.158-161
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• 2004

In this paper, we propose a level of contexts such as low level and high level contexts, and its criteria of categorization are the existence of interaction and composite process done by the inference mechanism. When there is no matching high level service for the associated high level context, this context is described as meaningless. If the services cannot be provided with the entities by the system, this situational information is of little consequence. To provide services with the entities, we propose "community computing" architectural concept which provide the high level service to a group of agents in a community, and can be managed by the service scenario