• Journal of the Korea Society of Computer and Information
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• v.4 no.4
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• pp.193-198
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• 1999

According to the spread of Asynchronous Tranfer Mode(ATM) Networks Telecommunication Management Network(TMN) over ATM Networks becomes an important issue. This paper presents with an Performance Analysis and the designs for comparing TCP/IP-Based Internet SNMP(Simple Network Management Protocol) and ITU-T's Distributed CMIP configuration. The experimental results shows that propose method is expected to be effectively used in Distributed Environments such as Internet, ATM. and mobile networks where interoperability and scalability are required.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.4
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• pp.71-84
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• 2019

Various researchers conducted the research on two-factor authentication suitable for wireless sensor networks (WSNs) after Das first proposed two-factor authentication combining the smart card and password. After then, To improve the security of user authentication, elliptic curve cryptography(ECC)-based authentication protocols have been proposed. Jiang et al. proposed a privacy-aware two-factor authentication protocol based on ECC for WSM for resolving various problems of ECC-based authentication protocols. However, Jiang et al.'s protocol has the vulnerabilities on a lack of mutual authentication, a risk of SID modification and a lack of sensor anonymity, and user's ID exposed on sensor node Therefore, this paper proposed security enhanced privacy-aware two-factor authentication protocol for wireless sensor networks to solve the problem of Jiang et al.'s protocol, and security analysis was conducted for the proposed protocol.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.6
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• pp.533-544
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• 1991

In this paper, the performance of bridges used to interconnect LAN to FD야 backbone networks as well as the performance of MAC protocols for FD야 backbone networks were thoroughly analyzed, The exhaustive service discipline and three ource models were applied to analyze the mean waiting time of the system. the performance is evaluated in terms of the service rate of bridge, total load of backbone. medium length of back bone, value of T and station latency. The result of analysis show that in general , processing delay of the system is mainly determined by bridge delays. But when processing time of bridge mereases, processing delays of the system are primarily determined by MAC protocols. Therefore, speed-up of processing time of bridge is necessary to efficiently use the high speed backbone networks.

• Journal of information and communication convergence engineering
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• v.9 no.4
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• pp.396-400
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• 2011

P2P(peer to Peer) network is a distributed network architecture composed of participants that make a portion of their resources directly available to other network participants, without the need for a central server. Currently, convergence network industry using wired and mobile are grows rapidly. So P2P protocols will be used between mobile and wired network. But current P2P protocols are focused on the wired networks only and there are no simulators for performance analysis of mobile P2P. In this paper, we design a P2P simulation system for performance analysis of P2P protocols in mobile, wired and convergence networks. It is constructed by a well-known mobile network simulator and wired based P2P protocol simulator. Finally we have implemented a smart TV test-bed using our P2P test-bed for convergence networks.

• Journal of Information Processing Systems
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• v.1 no.1 s.1
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• pp.55-61
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• 2005

In this paper we propose a distributed location management scheme to reduce the bottleneck problem of HLR in Large Mobile Networks (LMN). Using analytical modeling and numerical simulation, we show that replicating location information is both appropriate and efficient for small mobile networks. Then, we extend the scheme in a hierarchical environment to reduce the overhead traffic and scale to LMN. In numerical results, we show the superiority of our scheme compared to the current IS-95 standard scheme in IMT-2000 networks.

• Journal of the Korean Society of Industry Convergence
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• v.3 no.4
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• pp.361-367
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• 2000

This paper proposes an efficient feature extraction of the image data using nonlinear principal component analysis neural networks of a new learning algorithm. The proposed method is a learning algorithm with momentum for reflecting the past trends. It is to get the better performance by restraining an oscillation due to converge the global optimum. The proposed algorithm has been applied to the cancer image of $256{\times}256$ pixels and the coin image of $128{\times}128$ pixels respectively. The simulation results show that the proposed algorithm has better performances of the convergence and the nonlinear feature extraction, in comparison with those using the backpropagation and the conventional nonlinear PCA neural networks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.9
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• pp.4429-4445
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• 2019

As low-power and low-rate WSNs are being widely used for industrial applications, the scheduling of such applications becomes a critical issue to guarantee meeting the stringent requirements of determinism and tight latencies. This paper studies the link scheduling problem for real-time industrial applications in time-slotted channel hopping (TSCH) networks. We propose a heuristic algorithm for centralized link scheduling referred to as path-collision aware least laxity first (PC-LLF) algorithm, which dynamically prioritizes the packets based on the laxity time to the end-to-end deadlines and the amount of collisions that messages might deal with along their designated paths to the destination device. We propose schedulability analysis of real-time applications scheduled under our prioritization approach over TSCH networks, based on the literature on real-time schedulability analysis of multiprocessors and distributed systems. We show that our methodology provides an improved schedulability condition with respect to the existing approaches. Performance evaluation studies quantify to quantify the performance of our proposed approach under a variety of scenarios.

• The Journal of the Korea Contents Association
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• v.7 no.5
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• pp.1-9
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• 2007

Topology information can be constructed hierarchically in the networks and the process of aggregating topology information is known as TA(Topology Aggregation). It is very important for scalability in networks. In paticular, routing and TA algorithm are very much elements on networks performance in private networks to networks interface. Therefore, in this paper, we designed and implemented routing simulator for TA in private networks to networks interface. And we evaluated and analyzed the existent TA algorithm using the implemented simulator. The implemented simulator can be used valuably to developing TA algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5B
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• pp.741-752
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• 2010

The ability to seamlessly switch between the macro networks and femtocell networks is a key driver for femtocell network deployment. The handover procedures for the integrated femtocell/macrocell networks differ from the existing handovers. Some modifications of existing network and protocol architecture for the integration of femtocell networks with the existing macrocell networks are also essential. These modifications change the signal flow for handover procedures due to different 2-tier cell (macrocell and femtocell) environment. The handover between two networks should be performed with minimum signaling. A frequent and unnecessary handover is another problem for hierarchical femtocell/macrocell network environment that must be minimized. This work studies the details mobility management schemes for small and medium scale femtocell network deployment. To do that, firstly we present two different network architectures for small scale and medium scale WCDMA femtocell deployment. The details handover call flow for these two network architectures and CAC scheme to minimize the unnecessary handovers are proposed for the integrated femtocell/macrocell networks. The numerical analysis for the proposed M/M/N/N queuing scheme and the simulation results of the proposed CAC scheme demonstrate the handover call control performances for femtocell environment.

• Journal of Communications and Networks
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• v.11 no.6
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• pp.634-644
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• 2009

A diversity of wireless networks, with rapidly evolving wireless technology, are currently in service. Due to their innate physical layer vulnerability, wireless networks require enhanced security components. WLAN, WiBro, and UMTS have defined proper security components that meet standard security requirements. Extensive research has been conducted to enhance the security of individual wireless platforms, and we now have meaningful results at hand. However, with the advent of ubiquitous service, new horizontal platform service models with vertical crosslayer security are expected to be proposed. Research on synchronized security service and interoperability in a heterogeneous environment must be conducted. In heterogeneous environments, to design the balanced security components, quantitative evaluation model of security policy in wireless networks is required. To design appropriate evaluation method of security policies in heterogeneous wireless networks, we formalize the security properties in wireless networks. As the benefit of security protocols is indicated by the quality of protection (QoP), we improve the QoP model and evaluate hybrid security policy in heterogeneous wireless networks by applying to the QoP model. Deriving relative indicators from the positive impact of security points, and using these indicators to quantify a total reward function, this paper will help to assure the appropriate benchmark for combined security components in wireless networks.