• Journal of Korea Society of Digital Industry and Information Management
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• v.4 no.2
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• pp.29-37
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• 2008

Clustering allows hierarchical structures to be built on the nodes and enables more efficient use of scarce resources, such as frequency spectrum, bandwidth, and energy in wireless sensor networks (WSNs). This paper proposes a hierarchical clustering algorithm called EEHC which is more energy efficient than existing algorithms for WSNs, It introduces region node selection as well as cluster head election based on the residual battery capacity of nodes to reduce the costs of managing sensor nodes and of the communication among them. The role of cluster heads or region nodes is rotated among nodes to achieve load balancing and extend the lifetime of every individual sensor node. To do this, EEHC clusters periodically to select cluster heads that are richer in residual energy level, compared to the other nodes, according to clustering policies from administrators. To prove the performance improvement of EEHC, the ns-2 simulator was used. The results show that it can reduce the energy and bandwidth consumption for organizing and managing WSNs comparing it with existing algorithms.

• ETRI Journal
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• v.32 no.1
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• pp.84-92
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• 2010

This paper proposes the semaphore authority management (SAM) controller to optimize the dual-port SDRAM (DPSDRAM) in the mobile multimedia systems. Recently, the DPSDRAM with a shared bank enabling the exchange of data between two processors at high speed has been developed for mobile multimedia systems based on dual-processors. However, the latency of DPSDRAM caused by the semaphore for preventing the access contention at the shared bank slows down the data transfer rate and reduces the memory bandwidth. The methodology of SAM increases the data transfer rate by minimizing the semaphore latency. The SAM prevents the latency of reading the semaphore register of DPSDRAM, and reduces the latency of waiting for the authority of the shared bank to be changed. It also reduces the number of authority requests and the number of times authority changes. The experimental results using a 1 Gb DPSDRAM (OneDRAM) with the SAM controllers at 66 MHz show 1.6 times improvement of the data transfer rate between two processors compared with the traditional controller. In addition, the SAM shows bandwidth enhancement of up to 38% for port A and 31% for port B compared with the traditional controller.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.109-112
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• 2005

As the degree of use of network is increasing the need for building the basic of the stable network service is being needed a lot. Also the engineers require the traffic control for the best application and management and bandwidth management urgently. To solve these problems, there were no other ways of increasing the bandwidth of lines until now. However, this solution has the limit that the cost is too high and the traffic problem is growing continuously. On this study, it is suggested that through the planning the wired /wireless combination network design offering the service of QoS, Multicast, Mobile, realtime multimedia traffic delay without packet loss will be dealth with.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.4
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• pp.43-49
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• 2013

In this paper, it is designed inverted triangle structural planar monopole antenna with edge and rectangle slot for UWB(Ultra Wide Band) communication (3.1~10.6 GHz) and researched in about 5.8 GHz notch structure to prevent interference between UWB systems and existing wireless systems for using Wi-Fi service. The antenna have broadband property structurally through inverted triangle structural planar monopole which have edge. and rectangle form addition planned notch slot of 1 mm and height 0.1 mm. Monopole and ground of proposed antenna exist on coplanar plane, and excite as CPW. It used FR4 epoxy dielectric substrate of ${\varepsilon}r$=4.4, and the size is $20{\times}20{\times}1.6$ mm dimension. The measured results that are obtained return loss under -10 dB through 3.1~10.6 GHz(7.5 GHz) without Wi-Fi bandwidth and maximum gain of 8.44 dBi at E-plane. Radiation pattern is about the same that of dipole antenna at all frequency. And using notch slot and it will be able to confirm the quality which becomes notch from 5.8 GHz which are a radio LAN frequency range.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2B
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• pp.144-156
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• 2003

Internet/Intranet has been continuously enhanced by new emerging IP technologies such as differentiate service(DiffServ), IPSec(IP Security) and MPLS(Multi-protocol Label Switching) traffic engineering. According to the increased demands of various real-time multimedia services, ISP(Internet Service Provider) should provide enhanced end-to-end QoS(quality of service) and security features. Therefore, Internet and Intranet need the management functionality of sophisticated traffic engineering functions. In this paper, we design and implement the performance management functionality for the guaranteed end-to-end QoS provisioning on MPLS-based VPLS(Virtual Private LAN Service). We propose VPLS OAM(Operation, Administration and Maintenance) for efficient performance management. We focus on a scheme of QoS management and measurement of QoS parameters(such as delay, jitter, loss, etc.) using VPLS OAM functions. The proposed performance management system also supports performance tuning to enhance the provided QoS by re-adjusting the bandwidth of LSPs for VPLS. We present the experimental results of performance monitoring and analysis using a network simulator.

• Journal of Communications and Networks
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• v.3 no.4
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• pp.307-316
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• 2001

Two hard sub-problems have emerged relating to the use of mobile agents for service management tasks. First, what is their impact on security, and second, how can they receive a flexible capacity to adapt to an open range of different environments on demand, without introducing trio stringent prior assumptions. In this paper, we present work towards solving the second problem, which is of particular interest to management software, because it typically needs to excert fine-grained and therefore particular resource control. We suggest a mechanism that reassembles mobile agents from smaller sub-components during arrival at each hop. The process incorporates patterns of unmutable and mutable sub-components, and is informed by the conditions of each local environment. We discuss different kinds of software adaptation and draw a distinction between static and continuous forms. Our software prototype for dynamic adaptation provides a concept far exchanging environment-dependent implementations of mobile agents during runtime. Dynamic adaptation enhances efficiency of mobile code in terms of bandwidth usage and scalability.

• Journal of the Korea Society of Computer and Information
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• v.23 no.12
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• pp.145-151
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• 2018

While commercialization of IoT technologies in the safety management sector is being promoted in terms of industrial safety of large indoor businesses, implementing a system for risk management of small outdoor work sites with frequent site movements is not actively implemented. In this paper, we propose an efficient dynamic workload balancing strategy which combined low-power, wide-bandwidth (LPWA) communication and low-power Bluetooth (BLE) communication technologies to support customized risk management alarm systems for each individual (driver/operator/manager). This study was designed to enable long-term low-power collection and transmission of traffic information in outdoor environment, as well as to implement an integrated real-time safety management system that notifies a whole field worker who does not carry a separate smart device in advance. Performance assessments of the system, including risk alerts to drivers and workers via Bluetooth communication, the speed at which critical text messages are received, and the operation of warning/lighting lamps are all well suited to field application.

• International Journal of Computer Science & Network Security
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• v.22 no.4
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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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.11B
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• pp.956-966
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• 2004

Nowadays, NGN(Next Generation Network) is evolving into network with packet based QoS.\ulcorner This paper presents the recovery method as a selecting way of more efficient path in MPLS network that reduces the service interruption time. In order to increase the efficiency of usage of recovering resource which is one of major functions of disorder recovering, it opens the state information of each Node both to fault detector and bandwidth broker so that it reduces message transmission time for recovery when functional disorder occurs. in addition, by effective management and adjustment of required bandwidth of entire network depending on the changes of traffic load, it improves the efficiency of bandwidth usage. and in MPLS network supporting priority selection function, it allocates domains depending on the traffic relating to priority order to the entire network so that\ulcorner it efficiently allocates proper resources to the restoring process between the entry and the end for the traffic of high priority and for low priority traffic, it restores path oかy inside disordered domain. by doing this, it reduces resetting time and unnecessary massage transmission.

• The KIPS Transactions:PartC
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• v.15C no.4
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• pp.289-296
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• 2008

In wireless mesh network, studies on routing protocols have been actively carried out recently, and hop count is used as a major routing metric in destination-sequenced distance-vector (DSDV) routing protocol, which is a representative proactive routing protocol. Although hop-by-hop multi-path (HMP) DSDV and enhanced HMP (EHMP) DSDV routing protocols perform routing by considering both hop count and residual bandwidth within one hop distance nodes, it has a shortcoming that routing is carried out via non-optimal path from the aspect of end-to-end routing. In order to overcome the shortcoming, a cost-aware multi-path (CAMP) DSDV routing protocol is proposed in this paper, which considers hop count and end-to-end minimum residual bandwidth. Simulation results based on NS-2 show that the proposed routing protocol performs better than DSDV, HMP DSDV, and EHMP DSDV protocols from the aspect of throughput and packet delivery ratio, by appropriately using hop count and end-to-end minimum residual bandwidth information and has the same number of management messages with HMP DSDV and EHMP DSDV protocols.