• Convergence Security Journal
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• v.4 no.3
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• pp.1-8
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• 2004

Large distributed systems such as computational and data grids require that a substantial amount of monitoring data be collected for various tasks such as fault detection, performance analysis, performance tuning, performance prediction, security analysis and scheduling. to cope with this problem, they are needed network monitoring architecture which can collect various network characteristic and analyze network security state. In this paper, we suggest network performance and security analysis system based on network monitoring. The System suggest that users can see distance network state with tuning network parameters.

• Journal of Communications and Networks
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• v.12 no.1
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• pp.11-18
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• 2010

Diversity-multiplexing tradeoff (DMT) is an efficient tool to measure the performance of multiple-input and multiple-output (MIMO) systems and cooperative systems. Recently, cooperative multicast system with wireless network coding stretched tremendous interesting due to that it can drastically enhance the throughput of the wireless networks. It is desirable to apply DMT to the performance analysis on the multicast system with wireless network coding. In this paper, DMT is performed at the three proposed wireless network coding protocols, i.e., non-regenerative network coding (NRNC), regenerative complex field network coding (RCNC) and regenerative Galois field network coding (RGNC). The DMT analysis shows that under the same system performance, i.e., the same diversity gain, all the three network coding protocols outperform the traditional transmission scheme without network coding in terms of multiplexing gain. Our DMT analysis also exhibits the trends of the three network coding protocols' performance when multiplexing gain is changing from the lower region to the higher region. Monte-Carlo simulations verify the prediction of DMT.

• 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 Korean Society of Forest Science
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• v.84 no.1
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• pp.63-70
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• 1995

This paper discusses applications of neural network to stand stocking control problems. The scope of this research was to develop a neural network model for finding optimal stand management regimes and examining the performance of the model for field application. Performance was analyzed in consideration of the number of training examples and structural aspects of neural network. Research on network performance was based on extensive optimization studies for pure longleaf pine(Pinus palustris) stands. For experimental purposes. an existing nonlinear even-aged stand optimization model with a whole-stand growth and yield simulator was used to generate data samples required for the performance analysis.

• International Journal of Highway Engineering
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• v.20 no.1
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• pp.35-45
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• 2018

PURPOSES : This study examines the performance changes of road networks according to the strength of a disaster, and proposes a method for estimating the quantitative resilience according to the road-network performance changes and damage scale. This study also selected high-influence road sections, according to disasters targeting the road network, and aimed to analyze their hazard resilience from the network aspect through a scenario analysis of the damage recovery after a disaster occurred. METHODS : The analysis was conducted targeting Sejong City in South Korea. The disaster situation was set up using the TransCAD and VISSIM traffic-simulation software. First, the study analyzed how road-network damage changed the user's travel pattern and travel time, and how it affected the complete network. Secondly, the functional aspects of the road networks were analyzed using quantitative resilience. Finally, based on the road-network performance change and resilience, priority-management road sections were selected. RESULTS : According to the analysis results, when a road section has relatively low connectivity and low traffic, its effect on the complete network is insignificant. Moreover, certain road sections with relatively high importance can suffer a performance loss from major damage, for e.g., sections where bridges, tunnels, or underground roads are located, roads where no bypasses exist or they exist far from the concerned road, including entrances and exits to suburban areas. Relatively important roads have the potential to significantly degrade the network performance when a disaster occurs. Because of the high risk of delays or isolation, they may lead to secondary damage. Thus, it is necessary to manage the roads to maintain their performance. CONCLUSIONS : As a baseline study to establish measures for traffic prevention, this study considered the performance of a road network, selected high-influence road sections within the road network, and analyzed the quantitative resilience of the road network according to scenarios. The road users' passage-pattern changes were analyzed through simulation analysis using the User Equilibrium model. Based on the analysis results, the resilience in each scenario was examined and compared. Sections where a road's performance loss had a significant influence on the network were targeted. The study results were judged to become basic research data for establishing response plans to restore the original functions and performance of the destroyed and damage road networks, and for selecting maintenance priorities.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.513-519
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• 1989

Modeling of the network interface for MAP and its performance analysis is investigated in this study. The parameters for the network interface are selected and a special interest is concentrated on the parameters related to the performance of the network interface itself. A queueing model of the network interface is proposed and simulation is performed to validate the proposed model of the network interface.

• Korean Management Science Review
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• v.29 no.2
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• pp.167-184
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• 2012

Business diversification is inevitable to survive under the current competitive business environments. The advent of new businesses makes corporate governance more complicated through corporate combinations. Recent introduction of new accounting standard, International Financial Reporting Standards(IFRS), accelerates the need for corporate governance analysis. This study analyses the complex corporate governance system and its relation to the business performance using social network analysis. Corporate inter-governance networks can be visualized easily in a social network diagram. 552 corporate governance data are empirically analysed in the Korean stock market. The changes in In-Degree between networks are positively related with the changes in corporate sales volume. We can find the same results using operating profits as corporate performance proxy. The results show that social network analysis technique can be applied to investments in the stock markets.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.12
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• pp.1187-1192
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• 2016

Performance analysis results are limited to of network level, because network level transmission parameters are used for performance measure and analysis of network design, construction and operation on underwater MANET, With this way of performance analysis based on network level, it is not easy to analyze transmission performance related with user level transmission quality. In this paper, transmission performance focused on application traffic be required by user is investigated to supplement weakness of performance analysis based on network level. Voice traffic, which is expected to be increasingly used on underwater MANET, is considered as application service, Some conditions for underwater MANET will be proposed to support transmission quality, MOS, CCR and EED, etc.. A computer simulation based on NS-2 is used for performance measure, voice traffic is generated as VoIP specification.

• The KIPS Transactions:PartC
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• v.11C no.1
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• pp.123-134
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• 2004

The synchronized clock performance in the synchronization network and SDH transmission network design is an important element in aspect of guaranteeing network stability and data transmission. Consequently the simulator which can applicable various parameters and several input levels from the best state to the worst state for performance analysis of the synchronized clock is required in case of network design. Therefore, in this paper, 1 developed the SNCA and TNCA for analysis of the synchronized clock in the synchronization network and transmission network. And utilizing these simulators with various wander generation, node number and clock state, 1 obtained the synchronized clock characteristics and maximum network nodes In NE1, NE2 and NE3 transmission network and DOTS1, DOTS2 synchronization network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.5A
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• pp.441-450
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• 2007

In this paper, it is proposed the link performance analysis results using SNRAT(Satellite Network Resource Allocation & Analysis Tool) and verified the anticipated results by satellite communication network simulator. A communication satellite cannot be corrected or fixed for the error in orbit operation after launching unlike the ground operation equipment and has a restricted operation life. So, it is important to make possible to use satellite communications in the proper time. It is expected the link BER(Bit Error Rate), throughput and AJ(Anti-Jamming) performance using SNRAT tool before launching. And it is verified the performance of the repeaters and ground equipment specification using the satellite network simulator and is extracted the optimum operational scenarios through the tests of various network operational plans.