• Journal of the Korean Society for Precision Engineering
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• v.11 no.4
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• pp.126-137
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• 1994

Performance management of computer networks is intended to improve a given network performance in order for more efficient information exchange between subsystems of an integrated large-scale system. Importance of perfomance management is growing as many functions of the large- scale system depend on the quality of communication services provided by the network. The role of performance management is to manipulate the adjustable protocol parameters on line so that the network can adapt itself to a dynamic environment. This can be divided into two subtasks : performance evaluation to find how changes in protocol parameters affect the network performance and decision making to determine the magnitude and direction of parameter adjustment. This paper is the first part of the two papers focusing on conceptual design, development, and evaluation of performance management for token bus networks. This paper specifically deals with the task of performance evaluation which utilizes the principle of perturbation analysis of discrete event dynamic systems. The developed algorithm can estimate the network performance under a perturbed protocol parameter setting from observations of the network operations under a nominal parameter setting.

• Journal of Digital Convergence
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• v.15 no.6
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• pp.219-227
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• 2017

Network access control should be able to effectively block security threats to the IT infrastructure, such as unauthorized access of unauthorized users and terminals, and illegal access of employees to internal servers. From this perspective, it is necessary to build metrics based on relevant standards to ensure that security is being met. Therefore, it is necessary to organize the method for security evaluation of NAC according to the related standards. Therefore, this study builds a model that combines the security evaluation part of ISO / IEC 15408 (CC: Common Criteria) and ISO 25000 series to develop security metric of network access control system. For this purpose, we analyzed the quality requirements of the network access control system and developed the convergence evaluation metric for security of the two international standards. It can be applied to standardization of evaluation method for network access control system in the future by constructing evaluation model of security quality level of network access control system.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.05d
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• pp.1040-1045
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• 2002

This paper described the developed website usability evaluation system in terms of Kansei engineering using neural network. Developed system simultaneously operates with the MS Internet Explorer by entering the target URL for usability evaluation, and the results are learned using neural network. We firstly derived the Kansei adjectives and website usability factors and they were matched by the correspondence analysis. Then, highly corresponded adjectives were implemented on the system for the Kansei evaluation. Finally, the results showed the appropriate efficiency of developed algorithm and system for the website evaluation. If more subjects were used for the system learning, the efficiency of system could be improved.

• Journal of Korea Multimedia Society
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• v.22 no.7
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• pp.790-803
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• 2019

The effects of different heat treatments on the sensory characteristics of abalones are studied in this study. In this paper, the sensory evaluation of abalone samples under different heat treatment conditions is carried out, and the evaluation results are analyzed. The three-dimensional (3D) scanning and reverse engineering are used in tooth modeling of the sensory evaluation of abalone samples under different heat treatment conditions. Besides, the chewing movement models are simplified into three modes, including the cutting mode, compressing mode and grinding mode, which are simulated using finite element simulation. The elastic modulus of the abalone samples is obtained through the compression testing using a texture analyzer to distinguish their material properties under different heat treatments and to obtain simulated mechanical parameters. Finally, taking the mechanical parameters of the finite element simulation of abalone chewing as input and sensory evaluation parameters as the output, BP neural network is established in which the sensory texture evaluation model of abalone samples is obtained. Through verification, the neural network prediction model can meet the requirements of food texture evaluation, with an average error of 9.12%.

• Journal of the Korea Society for Simulation
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• v.10 no.2
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• pp.61-74
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• 2001

The reliability evaluation of the large scale network becomes very complicate according to the growing size of network. Moreover if the reliability is not constant but follows probability distribution function, it is almost impossible to compute them in theory. This paper studies the network evaluation methods in order to overcome such difficulties. For this an efficient path set algorithm which seeks the path set connecting the start and terminal nodes efficiently is developed. Also, various variance reduction techniques are applied to compute the system reliability to enhance the simulation performance. As a numerical example, a large scale network is given. The comparisons of the path set algorithm and the variance reduction techniques are discussed.

• Journal of Korean Institute of Industrial Engineers
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• v.12 no.1
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• pp.133-138
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• 1986

In this paper, we are modeling the problem of the reliability evaluation in the network with delay. The triconnected decomposition and factoring algorithm for the network reliability, known as the most efficient algorithm, does not work in this constrained problem. So, we propose some ideas that reduce the above constrained problem to the general network reliability problem. We also present an algorithm for the reliability evaluation in the network with delay based on these ideas.

• Convergence Security Journal
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• v.9 no.2
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• pp.33-39
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• 2009

The problems of current network security system, separated by a single element is checked. To improve this, this thesis is to find vulnerabilities in the network security systems, and network security systems, security equipment, organic to make sure each works is a comprehensive review. Automation also offers a way to check it, it was implemented.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.16 no.28
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• pp.181-186
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• 1993

The objective of this paper is to present a method for synthetic performance and quality evaluation of dial up network modem in users place. In the past, universally recognized criteria have not been available to model switched network modem performance. Reasonable assurance of modem performance on the public switched telephone network by standardized test channel which is suggested by ELA(Electronic Industries Association). These tests of modem from a variety manufacturers more reflective of actual performance on the network.

• Journal of Information Technology Services
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• v.17 no.1
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• pp.59-77
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• 2018

Software process (SP) authentication is a certification system designed in order to improve software process and ensure software reliability of the Korean small and medium enterprises (SMEs). It is composed of 3 grades, 17 evaluation items and 70 detailed evaluation items (software process). In order to certificate grade 2, 42 detailed evaluation items must be satisfied. In order to certificate grade 3, all 70 detailed evaluation items must be satisfied. SMEs are more vulnerable to manpower and material resources than the major company. Therefore, it is difficult for SMEs to invest in the long term to improve the software process. If we can provide the core evaluation items to SMEs, SMEs will be able to improve software quality more efficiently and effectively. It can be used as a short way to acquire SP authentication. The evaluation items of SP are defined as influencing each other. Therefore, the core evaluation items might be established using related techniques. Although we searched for previous researches and related informations, the associated study was insufficient. In this study, ANP (Analytic Network Process) technique was applied, and the core evaluation items of SP authentication were established. SMEs will be able to acquire SP authentication more easily using the core evaluation items. Finally, we expect that this study will be used as a basis material for creating the SP 2.0 version.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.261-264
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• 2008

IPv6 has been proposed and deployed to cater the shortage of IPv4 addresses. It is expected to foresee mobile phones, pocket PCs, home devices and any other kind of network capable devices to be connected to the Internet with the introduction and deployment of IPv6. This scenario will bring in more challenges to the existing network infrastructure especially in the network security area. Firewalls are the simplest and the most basic form of protection to ensure network security. Nowadays, firewalls' usage has been extended from not only to protect the whole network but also appear as software firewalls to protect each network devices. IPv6 and IPv4 are not interoperable as there are separate networking stacks for each protocol. Therefore, the existing states of the art in firewalling need to be reengineered. In our context here, we pay attention only to the IPv6 firewalls configuration anomalies without considering other factors. Pre-evaluation of security risk is important in any organization especially a large scale network deployment where an add on rules to the firewall may affect the up and running network. We proposed a new probabilistic based model to evaluate the security risks based on examining the existing firewall rules. Hence, the network administrators can pre-evaluate the possible risk incurred in their current network security implementation in the IPv6 network. The outcome from our proposed pre-evaluation model will be the possibilities in percentage that the IPv6 firewall is configured wrongly or insecurely where known attacks such as DoS attack, Probation attack, Renumbering attack and etc can be launched easily. Besides that, we suggest and recommend few important rules set that should be included in configuring IPv6 firewall rules.