• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2004년도 추계학술대회 및 정기총회
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• pp.527-530
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• 2004

This paper presents an optimization formulation for resource scheduling in Critical Resource Diagramming (CRD) of production scheduling networks. A CRD network schedules units of resources against points of needs in a production network rather than the conventional approach of scheduling tasks against resource availability. This resource scheduling approach provides more effective tracking of utilization of production resources as they are assigned or 'moved' from one point of need to another. Using CRD, criticality indices can be developed for resource types in a way similar to the criticality of activities in Critical Path Method (CPM). In our supply chain model, upstreams may choose either normal operation or expedited operation in resource scheduling. Their decisions affect downstream's resource scheduling. The suggested optimization formulation models resources as CRD elements in a production two-stage supply to minimize the total operation cost

• International Journal of Computer Science & Network Security
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• 제22권4호
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• pp.310-328
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• 2022

Internet of things (IoT) has emerged as the most popular technique that facilitates enhancing humans' quality of life. However, most time sensitive IoT applications require quick response time. So, processing these IoT applications in cloud servers may not be effective. Therefore, fog computing has emerged as a promising solution that addresses the problem of managing large data bandwidth requirements of devices and quick response time. This technology has resulted in processing a large amount of data near the data source compared to the cloud. However, efficient management of computing resources involving balancing workload, allocating resources, provisioning resources, and scheduling tasks is one primary consideration for effective computing-based solutions, specifically for time-sensitive applications. This paper provides a comprehensive review of the source management strategies considering resource limitations, heterogeneity, unpredicted traffic in the fog computing environment. It presents recent developments in the resource management field of the fog computing environment. It also presents significant management issues such as resource allocation, resource provisioning, resource scheduling, task offloading, etc. Related studies are compared indifferent mentions to provide promising directions of future research by fellow researchers in the field.

• 디지털융복합연구
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• 제14권10호
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• pp.303-310
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• 2016

인터넷의 경직성으로 인하여 다양한 서비스를 제공하기 어려운 문제를 해결하기 위한 가장 효과적인 방법이 네트워크 가상화 방안이다. 공통의 물리 네트워크 자원을 공유하는 가상 네트워크를 효율적으로 생성하기 위해서는 자원을 효율적으로 사용할 수 있는 방안이 필요하다. 이러한 한정된 물리 자원을 효율적으로 사용하기 위하여 본 논문에서는 사용중인 자원이라도 더 높은 서비스 우선순위를 갖는 가상 네트워크에 할당하는 방법을 제안한다. 높은 우선순위의 네트워크 생성 요청을 위하여 운용중인 낮은 우선순위의 가상 네트워크에서 효율적으로 대역폭을 회수하는 알고리즘을 제안한다. 제안하는 대역폭 할당 알고리즘은 낮은 우선순위를 갖는 가상 네트워크에서 서비스 지속성을 유지하면서 할당된 대역폭을 회수할 수 있다. 제안한 알고리즘의 실험을 통하여 약 8%정도의 가상 네트워크 생성 수락률의 향상을 확인하였다.

• 한국통신학회논문지
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• 제37B권9호
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• pp.822-830
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• 2012

한국을 대표하는 연구망인 KREONET은 OGF에서 제안한 NSI (Network Service Interface) 기반의 네트워크 자원서비스에이전트 (NSA) 기술을 개발하였다. 개발된 NSA은 웹 서비스를 지원하며 MPLS 제어평면 기술을 이용하여 사용자가 원하는 시간 때에 네트워크 자원 (대역폭, 경로)을 예약, 구성, 해제, 종결 해 줄 수 있다. 본 논문에서는 개발되어진 NSA의 시스템 블록 및 NSI 인터페이스 메시지 흐름에 대하여 알아본다. 또한 NSI 요청 메시지를 위한 클라이언트, 확인 메시지를 위한 서버로 동작하는 Reguester NSA를 웹포털시스템으로 구현하여 개발된 NSA과의 통신을 통해 NSI 연결 예약 서비스를 시험하였다. 사용자로부터 제공 되어진 예약정보를 받아 웹 포털 시스템과 NSA과의 NSI 인터페이스 메시지를 통해 네트워크 자원을 예약, 구성, 해제, 종결 할 수 있었다.

• Journal of Communications and Networks
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• 제18권1호
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• pp.112-122
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• 2016

Cognitive radio (CR) is considered an attractive technology to deal with the spectrum scarcity problem. Multi-radio access technology (multi-RAT) can improve network capacity because data are transmitted by multiple RANs (radio access networks) concurrently. Thus, multi-RAT embedded in a cognitive radio network (CRN) is a promising paradigm for developing spectrum efficiency and network capacity in future wireless networks. In this study, we consider a new CRN model in which the primary user networks consist of heterogeneous primary users (PUs). Specifically, we focus on the energy-efficient resource allocation (EERA) problem for CR users with a special location coverage overlapping region in which heterogeneous PUs operate simultaneously via multi-RAT. We propose a two-tier crossover genetic algorithm-based search scheme to obtain an optimal solution in terms of the power and bandwidth. In addition, we introduce a radio environment map to manage the resource allocation and network synchronization. The simulation results show the proposed algorithm is stable and has faster convergence. Our proposal can significantly increase the energy efficiency.

• 정보처리학회논문지C
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• 제15C권6호
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• pp.557-566
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• 2008

차세대네트워크(Next Generation Network, NGN)은 하부의 전송 매체와 상관없이 데이터 전송의 품질을 보장하는 광대역망으로 NGN에서 주요 서비스로 대두되고 있는 실시간 방송 서비스 등은 멀티캐스트 기법을 필요로 하고 있다. 그러나 기존의 IP 멀티캐스트는 실제로 적용되기에는 많은 제약점을 지니고 있다. 이를 해결하기 위한 오버레이 멀티캐스트는 IP 멀티캐스트를 대신해 유연성과 확장성을 제공하여 효과적인 멀티미디어 멀티캐스트 전송을 가능하게 하는 기술로 활발히 연구 중에 있는 가상 네트워크다. 본 연구에서는 각 수신자가 속해있는 목적지 네트워크에 에이전트를, 미디어 서버가 위치한 소스 네트워크에는 전체 오버레이 멀티캐스트 토폴로지를 관리하는 매니저를 설계하였다. 매니저와 에이전트는 서로 통신하면서 네트워크의 자원 상태를 기반으로 한 서비스 제공을 수행하는 역할을 담당한다. 이렇게 함으로써 NGN 환경에서 QoS를 보장하는 멀티캐스트 환경을 제공할 수 있으며 이는 NGN 구조의 품질관리 기능인 RACF(Resource and Admission Control Functions)를 기반으로 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권6호
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• pp.2282-2303
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• 2021

To solve the problems of heavy computing load and system transmission pressure in energy internet (EI), we establish a three-tier cloud-edge integrated EI network based on a cloud-edge collaborative computing to achieve the tradeoff between energy consumption and the system delay. A joint optimization problem for resource allocation and task offloading in the threetier cloud-edge integrated EI network is formulated to minimize the total system cost under the constraints of the task scheduling binary variables of each sensor node, the maximum uplink transmit power of each sensor node, the limited computation capability of the sensor node and the maximum computation resource of each edge server, which is a Mixed Integer Non-linear Programming (MINLP) problem. To solve the problem, we propose a joint task offloading and resource allocation algorithm (JTOARA), which is decomposed into three subproblems including the uplink transmission power allocation sub-problem, the computation resource allocation sub-problem, and the offloading scheme selection subproblem. Then, the power allocation of each sensor node is achieved by bisection search algorithm, which has a fast convergence. While the computation resource allocation is derived by line optimization method and convex optimization theory. Finally, to achieve the optimal task offloading, we propose a cloud-edge collaborative computation offloading schemes based on game theory and prove the existence of Nash Equilibrium. The simulation results demonstrate that our proposed algorithm can improve output performance as comparing with the conventional algorithms, and its performance is close to the that of the enumerative algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권3호
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• pp.794-815
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• 2023

The rapid development of mobile communication not only has made the industry gradually diversified, but also has enhanced the service quality requirements of users. In this regard, it is imperative to consider jointly network slicing and mobile edge computing. The former mainly ensures the requirements of varied vertical services preferably, and the latter solves the conflict between the user's own energy and harsh latency. At present, the integration of the two faces many challenges and need to carry out at different levels. The main target of the paper is to minimize the energy consumption of the system, and introduce a multi-slice joint task offloading and resource allocation scheme for massive multiple input multiple output enabled heterogeneous networks. The problem is formulated by collaborative optimizing offloading ratios, user association, transmission power and resource slicing, while being limited by the dissimilar latency and rate of multi-slice. To solve it, assign the optimal problem to two sub-problems of offloading decision and resource allocation, then solve them separately by exploiting the alternative optimization technique and Karush-Kuhn-Tucker conditions. Finally, a novel slices task offloading and resource allocation algorithm is proposed to get the offloading and resource allocation strategies. Numerous simulation results manifest that the proposed scheme has certain feasibility and effectiveness, and its performance is better than the other baseline scheme.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권2호
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• pp.522-541
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• 2016

Network virtualization provides an effective way to overcome the Internet ossification problem. As one of the main challenges in network virtualization, virtual network embedding refers to mapping multiple virtual networks onto a shared substrate network. However, existing heuristic embedding algorithms evaluate the embedding potential of the nodes simply by the product of different resource attributes, which would result in an unbalanced embedding. Furthermore, ignoring the hops of substrate paths that the virtual links would be mapped onto may restrict the ability of the substrate network to accept additional virtual network requests, and lead to low utilization rate of resource. In this paper, we introduce and extend five node attributes that quantify the embedding potential of the nodes from both the local and global views, and adopt the technique for order preference by similarity ideal solution (TOPSIS) to rank the nodes, aiming at balancing different node attributes to increase the utilization rate of resource. Moreover, we propose a novel two-stage virtual network embedding algorithm, which maps the virtual nodes onto the substrate nodes according to the node ranks, and adopts a shortest path-based algorithm to map the virtual links. Simulation results show that the new algorithm significantly increases the long-term average revenue, the long-term revenue to cost ratio and the acceptance ratio.

• 한국정보과학회논문지:시스템및이론
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• 제33권9호
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• pp.666-676
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• 2006

유비쿼터스 컴퓨팅 환경이 점차 확산되면서, 그 안에서 제공되는 다양한 리소스에 대한 효율적인 발견 전략들이 그 중요성을 더하고 있다. 특히, 유비쿼터스 환경을 구성하는 다양한 네트워크 중에서, 이동 애드혹 네트워크의 효율적인 리소스 발견 전략이 근래에 주목받고 있는데, 이는 이 네트워크를 구성하는 무선 노드들의 높은 이동성과 이들이 소유한 자원들의 제약 사항 등 고려해야 할 요소들이 많기 때문이다. 이 논문에서는 이러한 이동 애드혹 네트워크를 위한 적응적이고 효율적인, 유비쿼터스 환경의 이 기종 네트워크와 연동 가능한 리소스 발견 전략을 제시한다.