• International Journal of Advanced Culture Technology
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• v.8 no.3
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• pp.292-299
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• 2020

This paper presents an evaluation criteria of an information system availability for guaranteeing availability (service target level) from the perspective of the SLA contract and its technical point of view. In order to verify the effectiveness for information system failure and availability guarantee measures, three cases were examined. In summary, the failure time was reduced by 32% ~ 62% after applying the availability guarantee measure, verifying the excellence in the evaluation of an information system availability.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9B
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• pp.818-825
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• 2004

High availability means Service-technology that can provide any solution when occur a problem in relation to hardware, software, network etc. We are in the times that the network computing service are essential to our daily life. So the importance of the high availability is being higher and higher in this social change such as the arrival of information anger times, e-commerce the extension of multi-media service etc. In this thesis, I analyzed about High-availability Linux Server for Multimedia Tourism Information System, and I proposed an alternative plan which related with its result.

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.1
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• pp.25-34
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• 2021

Availability is one of the important factor for developing weapon system, because it indicates the mission capability and sustainable life cycle management of weapon system. Recently, as weapon system becomes more advanced and more complex, availability estimation becomes more important to reduce the life cycle cost of weapon system. Modeling and simulation(M&S) is useful method to describe the availability of complex weapon system applying operational environment and maintenance plan. Especially agent based model(ABM) has the strength to describe interactions between agents and environments in complex system. Therefore, this paper presents the availability estimation of weapon system using agent based model. The sample data of part list and reliability analysis is applied to build availability estimation model. User agent and mechanic agent are developed to illustrate the behavior of operation and maintenance using formal specification. Storage reliability is applied to describe failure of each parts. The experimental result shows that this model is quite useful to estimate availability of weapon system. This model may estimate more reasonable availability, if full scale data of weapon system and real field data of operation is provided.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2323-2330
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• 2014

Most organizations are more depending on information system in advanced information society. According to this current, unrapid reaction to system failure can cause a fatal effect to a credibility of the organization. An excessively high level of dependence on information system at work makes itself as a primary target of cyber terror. The stability of university's information system is especially weaker than the enterprise's but policy support for securing availability is inadequate. In this paper, we consider the recovery system toward to disorder of university's school affairs information system theoretically and suggest high availability PC based academic administration system.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.3
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• pp.547-560
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• 2014

Smart Grid, which maximize the efficiency of energic utilization by applying Information and Communication Technology to Power Grid, requires high availability. Attacks, such as DDoS, which cause suspension of service and lead to social disruptions have recently been increasing so that systematic management over availability becomes more important. In this paper, we presents a new evaluation criteria of Korean Smart Grid by comparing availability assessment items of international standards specified in management system and then overcome the limitations of availability evaluation of existing information security management system.

• Journal of Applied Reliability
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• v.8 no.4
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• pp.193-204
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• 2008

In this paper, we proposed availability evaluation of network in mobile communication network that have hand off structure. Radio mobile communication network is essential hand off action to keep communication that is no discontinuance by transfer of terminal. Part by state and hand off state ago hand off by transfer of terminal and communication network is estimated performance according to the hand off rate and hand off completion rate of system. we applied MS, SM, MM communication structure in radio CORBA for network availability evaluate. System availability in mobile communication network that can repair that propose in this study uses the hand off rate and hand off completion rate of system by transfer of terminal and availability of whole system did evaluate.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.155-158
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• 1998

The KOMPSAT system incorporates multiple missions designed to provide various applications in the field of Korean peninsula observation covering land, sea and coastal zones. The missions are Korea cartography (1:25,000 scale maps of the Korean peninsula), biological oceanography and science instrument accommodation. The operational availability of KOMPSAT TTC system should be predicted more accurately because its failure has a significant influence on satellite command and tracking and on satellite data collection. In this paper, system availability structure of KOMPSAT TTC system are made and availability of KOMPSAT TTC system is analyzed aspect to the system operation in accordance with logistic condition.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.1
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• pp.80-86
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• 2007

The concept of the coverage has been played an important role in the area of reliability evaluation of a system. The widely used measures of reliability include the m time between failures, the availability and so on. In this paper, we propose an estimator of the coverage probability in a redundant system with a control unit and investigate some moments of the proposed estimator. And assuming exponential distribution of all units, we conduct a simulation study for calculating the estimates of the coverage probability and its confidence bounds. An example of evaluating the availability of an optical transportation system is illustrated.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.9
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• pp.1717-1722
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• 2016

Availability, one of the important metrics used to assess the performance of network system, is defined as the probability that a system is operational at a given point in time under a given set of environmental conditions. To improve the availability of the network service, the redundancy models and the rejuvenation schemes are the effective schemes to be typically used. In this paper, we analyse the effect of 2N redundancy model and/or rejuvenation scheme on the availability of network service. The 2N redundancy model consists of one active and one standby component and the performance of time-based rejuvenation scheme mainly depends on its rejuvenation period. We design stochastic reward net model for the 2N redundancy model with time-based rejuvenation scheme and analyse the service availability of the model using stochastic Petri net package. We provide some numerical examples of the service availability, which shows that the system with rejuvenation has higher availability than the system without rejuvenation.

• Journal of the Korea Society of Computer and Information
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• v.22 no.12
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• pp.179-186
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• 2017

Managing students' data is a high prioritized duty of the university administration since most of the school affairs are proceed based on that database. Universities have invested in IT assets such as servers, storage, database, and networks. However, continuing investment in IT infrastructure is impossible due to limited budget and rapid changes in the educational environment. As cloud computing diffuse, universities are trying to reduce costs and improve efficiency by increasing server utilization, unlike when physically investing. We designed a hypothetical academic information management system based on cloud computing by utilizing the advanced server virtualization technology. This administrative cloud system allows universities to improve the availability of the system with low cost. The system demonstrates its flexibility of using data resources and immediacy of resumption.