• Journal of Satellite, Information and Communications
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• v.2 no.2
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• pp.85-91
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• 2007

The satellite networks provide global coverage. The integration of terrestrial networks with a satellite network is the most attractive approach to develop a global communication system. The IP Multimedia Subsystem (IMS) is intended to be the system that will merge the internet with the telecom world. A user with a dual-mode terminal can access both the satellite network and terrestrial network. The seamless handoff between two networks and a user's QoS level is the major issue concerning this integration. In this paper, we propose IMS-based satellite/terrestrial integrated network architecture for a global communication system. Based on the proposed architecture, an inter-network handoff and end-to-end soft QoS procedure is discussed. Our proposed soft QoS scheme is also analyzed to calculate the number of rejected calls.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5B
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• pp.491-497
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• 2004

In this Paper, we W a Hovel global traffic control architecture to isolate malicious network attacks and protect network infrastructure in Internet backbone networks. Unlike existing methods based on individual packets or flows, since the proposed detection and control methods are operated on the aggregate traffic level, the computational complexity can k significantly reduced, and they are applicable to develop a global defense architecture against network attack. Experimental results show that the proposed scheme can detect the network attack symptoms very exactly and quickly and protect the network resources as well as the normal traffic flows very efficiently.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.1
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• pp.39-45
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• 2014

This paper proposes an architecture of a sensor network for gathering data under a powerful beam cluster tree architecture. This architecture is used when there is a need to gather data from sensor node where there is no sink node connected to an existing network, or it is required to get a series of data specific to an event or time. The transmit distance of the beam signal is longer than that of the usual sensor node. The nodes of the network make a tree network when receiving a beam message transmitting from the powerful root node. All sensor nodes in a sink tree network synchronize to the superframe and know exactly the sequence value of the current superframe. When there is data to send to the sink node, the sensor node sends data at the corresponding allocated channel. Data sending schemes under the guaranteed time slot are tested and the delay and jitter performance is explained.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.10
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• pp.40-50
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• 1999

The novel network architecture is recently required to accommodate a variety and intelligence of communication services. It is also required to provide customized network functions and to efficiently satisfy a various user's requirements. Accordingly, open network architecture based on ATM transport network features has been mainly studied in communication network. This paper evaluates the VSN(Virtual Switch Network) characteristics in the call processing of IMT-2000 switching system, which is composed of VSN instead of ATM switch network. VSN means switch network which is composed of ATM transport network. As a result, this paper proposes new VSN based ATM-MSC architecture with integrated call and connection control systems. and evaluates call processing delay characteristics using call process procedures. Internal call processing delay is increased approximately 3.5msec than the conventional ATM switching system. The experimental values applied in the analysis condition are the load 0.8, and the 100km distance between CCCPs(Call and Connection Control Processors) and VSNs. It is confirmed that the VSN has the potentiality in the practical implementation.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.269-276
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• 2022

The robustness of a supply chain (i.e., the ability to cope with external and internal disruptions and disturbances) becomes more critical in ensuring the success of a construction project because the supply chain of today's construction project includes more and diverse suppliers. Previous studies indicate that topological features of the supply chain critically affect its robustness, but there is still a great challenge in characterizing and quantifying the impact of network topological features on its robustness. In this context, this study aims to identify network measures that characterize topological features of the supply chain and evaluate their impact on the robustness of the supply chain. Network centrality measures that are commonly used in assessing topological features in social network analysis are identified. Their validity in capturing the impact on the robustness of the supply chain was evaluated through an experiment using randomly generated networks and their simulations. Among those network centrality measures, the PageRank centrality and its standard deviation are found to have the strongest association with the robustness of the network, with a positive correlation coefficient of 0.6 at the node level and 0.74 at the network level. The findings in this study allows for the evaluation of the supply chain network's robustness based only on its topological design, thereby enabling practitioners to better design a robust supply chain and easily identify vulnerable links in their supply chains.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.4B
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• pp.424-434
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• 2004

Ubiquitous network consists of various devices using several heterogeneous protocols and requires seamless communication between devices. This paper proposes a new hierarchical event service and multiple event server architecture to implement the service under ubiquitous environment. The proposed event service classifies devices by logical and physical location to abstract the idiosyncrasy of used protocols, and reduces network load. Due to the design consideration, the proposed architecture removes transfer of duplicated event data effectively. As a result, we can guarantee the reliable event delivery. The prototype multiple event server architecture was implemented according to the proposed idea and evaluated its performance under a home network test bed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3A
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• pp.347-357
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• 2004

Network systems have been developed to meet the high performance of forwarding packets and flexibility for providing various services, so network processor emerged. In order to improve the performance of network processors, fast external interface and special functional units have been used. Recently as an architectural method of improving performance, the SMT(Simultaneous Multi Threading) architecture is proposed, but this architecture is difficult to implement due to its complexity. Therefore research for architectural optimization is needed to develop the SMT network processors. In this paper we analyze each functional units on performing network algorithms and propose an optimized SMT network Processor architecture.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.06a
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• pp.97-106
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• 2002

Grid makes it possible to cooperate with other network area by sharing and using distributed resources. In order to manage effectively large-scale Grid network resources, Grid NOC needs monitoring architecture that can manage distributed resources in one time. Being restricted within specific managing area, conventional network management system has limitation in extension of managing area and in general management of heterogeneous resource. In this paper, we design a monitoring architecture that can take in the situation and has scalability. In the monitoring architecture the network areas publish information in a common directory service, and then Grid NOC can connect to the network areas directly by using this information. Therefore, it makes us possible to manage overall large-scale resource of Grid network reducing load.

• ETRI Journal
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• v.42 no.2
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• pp.186-195
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• 2020

Software-defined networking (SDN) acts as a centralized management unit, especially in a network with devices that operate under the transport layer of the OSI model. However, when a network with layer 7 middleboxes (MBs) is considered, current SDNs exhibit limitations. As such, to achieve a real-centralized management unit, a new architecture is required that decouples the data and control planes of all network devices. In this report, we propose such a complementary architecture to the current SDN in which SDN-enabled MBs are included along with contemporary SDN-enabled switches. The management unit of this architecture improves network performance and reduces routing cost by considering the status of the MBs during flow forwarding. This unit consists of the following two parts: an SDN controller (SDNC) and a middlebox controller (MBC). The latter selects the best MBs for each flow and the former determines the best path according to its routing algorithm and provides information via the MBC. The results show that the proposed architecture improved performance because the utilization of all network devices including MBs is manageable.

• Journal of Korea Society of Industrial Information Systems
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• v.7 no.4
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• pp.90-99
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• 2002

Grid makes it possible to cooperate with other network area by sharing and using distributed resources. In order to manage effectively large-scale Grid network resources, Grid NOC needs monitoring architecture that can manage distributed resources in one time. Being restricted within specific managing area conventional network management system has limitation in extension of managing area and in general management of heterogeneous resource. In this paper, we design a monitoring architecture that can take in the situation and has scalability. In the monitoring architecture the network areas publish information in a common directory service, and then Grid NOC can connect to the network areas directly by using this information. Therefore, it makes us possible to manage overall large-scale resource of Grid network reducing load.