• IE interfaces
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• v.15 no.3
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• pp.247-255
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• 2002

For the recent multimedia service, the network should be fast, stable, and reliable. In order to provide reliability of the network, certain survivability of the network, which guarantees it's functions even though there is some failure on the network, should be satisfied. Also, for a pair of nodes on the network, there must be paths of which numbers of hops are within a certain limit for realtime service between them. In this paper, we propose a longest shortcut method for solving the survivable network design problems with hop limit. Through the computational results, we compare the efficiency of the method with an existing shortest shortcut method and find that the proposed method is more efficient than the shortest shortcut method.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.944-946
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• 1998

We evaluated cell survivability by changing RLC value on HV impulse network. When the L value is changed from 0 to 10mH in this circuit. we found that cell survivability is shown large decline with 4mH of L value. I respect to this result, when waveshapes of oscillatory decay are presented along the variation of L value in RLC circuit, we analyzed whether discharge waveform properties have an effect on sterilization ratio, and measured threshold voltage as the minimum peak voltage of a single pulse which can sterilize cells. Finally, we found that the sterilization effect was related to number of threshold voltage waveforms being applied.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05c
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• pp.1965-1968
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• 2003

The importance of Security measures by means of Physical Security, Network Security and Online/Internet Security. Lack of security is one of the primary obstacles in fielding many technologies in both commercial and DoD networks. Moreover, Internet censorship may be growing and is becoming increasingly sophisticated. In this paper, we will evaluate the Practice to Policy to Theory Approach for survivability by means of software rejuvenation models. These models would be assessed the effectiveness of proactive fault management in operational software systems and determined optimal times to perform rejuvenation.

• Korean Management Science Review
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• v.11 no.3
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• pp.103-128
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• 1994

Due to the trend of evolution toward a broadband communication network with fiber-optics, the design and operation of fiber-optic network have been received a great deal of research attention recently. Furthermore, even a single fiber link failure in the network may result in severe service loss. Thus, the network survivability becomes an importantissue in planning and designing the network. This survey is on modelling of various fiber-optic subscriber loop network(FSLN) design problems, which are essential ones for providing broadband communication services and B-ISDN services. Models are classified and investigated as either conventional decomposition-iteration approach or integrated design method. To build survivable networks, SHR models are also suggested by ring control schemes. The result of this study will be effectively applied to build a design model for FSLN in the practical applications.

• IE interfaces
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• v.9 no.3
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• pp.92-100
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• 1996

The current copper-based communication network is going to be replaced with an optic fiber network. The new technology allows a larger amount of information to be transmitted than before. Due to its bandwidth and relatively high installation cost, however, the optic fiber network does not exhibit the inherent structural redundancy provided by the conventional copper-based network. We propose to supply it by adding multiple paths between important nodes. This so-called network survivability problem is computationally expensive to solve exactly. We report the application of a heuristic algorithm to this problem. Also discussed is the issue of how to make use of existing conduits.

• The KIPS Transactions:PartC
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• v.10C no.1
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• pp.111-118
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• 2003

Network reliability means network ability which perform normal operation of network components within defined time period, on the other hand, network survivability is the index of normal operation in nerwork failure. In occurrence of network failure, network operator is interested in the measurement of network survivability, but, in a view of subscribers, it is more interested in how many subscribers are out of service and how long the out of service state lasts. In this paper, a service outage evaluation model fitted for telecommunication network in Korea is proposed, which measures the impacts of subscribers in case of network failure which induces a service outage. The outage evaluation result of "Mobile to Land" service outage which has 30.000 subscribers affected for 30 minutes is 2.5. This value is 5 times larger than that of the same service outage which has 10,000 subscribers affected for 30 minutes, i.e, the impact of subscribers in the former case is 5 times larger than that of the latter case. If 30,000 subscribers have isolated in "Mobile to Land," "Local Mobile to Mobile" service for 30 minutes by the exchange out of order in PCS network, then the evaluation result of this service outage will be 3.75.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10B
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• pp.1832-1840
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• 1999

This paper proposed a network to implement all optical bidirectional BLSR/4 WDM/SHR allowing restoration in the event of a failure. The proposed network can provide a high degree of transparency using all-optical components with no electric implementation and effective failure restoration due to BLSR/4 WDM/SHR architecture. This paper also presented a genetic simulation model for the survivability analysis of the proposed BLSR/4 WDM/SHR under failure scenarios, the restoration performance of the proposed network is analyzed in terms of performance parameters such as propagation time, processing time, optical switch time.

• Information and Communications Magazine
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• v.19 no.8
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• pp.128-136
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• 2002

It is an active security that has the research field which has more powerful responding mechanism comparing to current network security technology, has an ability to introduce new security mechanism according to changing our environments, and can support effective security management. Our goal is to introduce a new category of internet security technologies on network survivability: active security technology. It is a new security technology that blocking network or computers. before malicious traffics are reached to them, including protecting hosts or small area network from hackers.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.1B
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• pp.15-30
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• 2000

The important considerations in the design of fiber-optic networks are reliability and survivability preparing against a failure. The SDH(Synchronous Digital Hierarchy), the international standard of optical transmission, offers several network reconfiguration methods that enable network to be automatically restored from failure. One of the methods is the SHR(Self Healing Ring), which is a ring topology system. Most network providers have constructed their backbone networks with SHR architecture since it can provide survivability economically. The network architecture has eventually evolved into a multi-ring network comprised of interconnected rings. This paper addresses multi-ring network design problems is to minimize ring-construction cost. This problem can be formulated with MIP(mixed integer programming) model. However, it is difficult to solve the model within reasonable computing time on a large scale network because the model is NP-complete. Furthermore, in practice we should consider the problem of routing demands on rings to minimize total cost. This routing problem involves multiplex bundling at the intermediate nodes. A family of heuristic algorithms is presented for this problem. These algorithms include gateway selection and routing of inter-ring demands as well as load balancing on single rings. The developed heuristic algorithms are applied to some network provider's regional and long-distance transmission networks. We show an example of ring design and compare it with another ring topology design. Finally, we analysis the effect bundling.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.7
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• pp.1874-1893
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• 2012

An approach to detect abnormal activities based on reputations created individually by each node is vulnerable to a false accusation since intrusion detection in ad-hoc networks is done in a distributed and cooperative manner. Detection of false accusation is considered important because the efficiency or survivability of the network can be degraded severely if normal nodes were excluded from the network by being considered as abnormal ones in the intrusion detection process. In this paper, we propose an improved reputation-based intrusion detection technique to efficiently detect and manage false accusations in ad-hoc networks. Additionally, we execute simulations of the proposed technique to analyze its performance and feasibility to be implemented in a real environment.