• 한국항해학회지
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• 제24권1호
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• pp.47-56
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• 2000

As a shipboard dependency for the safety and reliability becomes very important, the need for solid systems providing non-stop workload has been increased. This system is heartbeat that transmits shipboard state, audit and control information to the land. So, this paper describes a ship's LAN configuration method for the safety and reliability. In order to achieve these requirements, network, server and disk fault tolerance techniques are surveyed, and dual network configuration model, cluster server configuration method are presented and tested based on the survey.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2005년도 하계학술대회
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• pp.431-435
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• 2005

이동통신망을 설계하고 최적화하기 위한 무선망 분석 시뮬레이션 툴은 다양한 분석기능을 가지고 있다. 전파전파예측을 비롯한 용량, 커버리지 분석까지 가능한 이러한 시뮬레이션 툴의 신뢰도는 망 성능에 절대적인 영향을 미친다. 특히 데이터 서비스 중심으로 망이 고도화 되어가면서 시뮬레이션 툴의 신뢰도에 대한 기준 정립이나 신뢰도 향상 기법에 대한 체계적인 연구가 요구된다. 본 논문에서는 이러한 시뮬레이션 툴의 기본 기능에 대한 신뢰도를 향상시키는 구체적인 절차나 기법에 대해 이론적/경험적으로 접근해 구체화시키고 이를 바탕으로 과학적인 신뢰도 향상 기법을 도출해낸다.

• Smart Structures and Systems
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• 제26권2호
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• pp.175-184
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• 2020

Conventional Monte Carlo simulation-based methods for seismic risk assessment of water networks often require excessive computational time costs due to the hydraulic analysis. In this study, an Artificial Neural Network-based surrogate model was proposed to efficiently evaluate the flow-based system reliability of water distribution networks. The surrogate model was constructed with appropriate training parameters through trial-and-error procedures. Furthermore, a deep neural network with hidden layers and neurons was composed for the high-dimensional network. For network training, the input of the neural network was defined as the damage states of the k-dimensional network facilities, and the output was defined as the network system performance. To generate training data, random sampling was performed between earthquake magnitudes of 5.0 and 7.5, and hydraulic analyses were conducted to evaluate network performance. For a hydraulic simulation, EPANET-based MATLAB code was developed, and a pressure-driven analysis approach was adopted to represent an unsteady-state network. To demonstrate the constructed surrogate model, the actual water distribution network of A-city, South Korea, was adopted, and the network map was reconstructed from the geographic information system data. The surrogate model was able to predict network performance within a 3% relative error at trained epicenters in drastically reduced time. In addition, the accuracy of the surrogate model was estimated to within 3% relative error (5% for network performance lower than 0.2) at different epicenters to verify the robustness of the epicenter location. Therefore, it is concluded that ANN-based surrogate model can be utilized as an alternative model for efficient seismic risk assessment to within 5% of relative error.

• 한국통신학회논문지
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• 제13권5호
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• pp.379-389
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• 1988

본 논문에서는 통신방의 2-상태 스취칭 실패함수를 구하기 위한 알고리즘과 단섭간 신뢰도 계성방법을 제시하였다. 통신망을 그래프로 모형화하고, 이 그래프에 대한 일련의 행열변환을 함으로서 모든 통신통로를 차단하는 최초컷-\ulcornerV 행열을 구하였으며 최소 컷-\ulcornerV행열로부터 2-상태 스위칭 실패함수를 구하였다. 또한 2-상태 스위칭 실패함수에 확률변수를 대응시켜 통신망의 단점간 신뢰도를 계정하였다. 제안된 알고리즘을 설명하기 위하여 몇가지 예를 보였으며 복잡하고 규모가 큰 망에 대한 단점간 신뢰도를 계정하기 위해서 전산기 프로그램을 제시하였다.

• 정보보호학회논문지
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• 제23권2호
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• pp.157-168
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• 2013

소셜 네트워크 서비스는 생산자와 소비자의 구분 없이 모든 사용자가 직접 정보를 생산, 가공, 유통할 수 있는 양방향 미디어이다. 이용자 수가 빠르게 증가하면서 사용자들이 다양한 정보를 획득하고 공유할 수 있게 되었지만 서비스 상에서 신뢰할 수 없는 정보들의 확산으로 인한 문제점이 발생하고 있다. 또한, 개방적 환경이라는 점을 악용하여 사용자의 프라이버시를 침해하고 서비스 및 사용자의 신뢰도를 낮추는 문제가 확산되고 있다. 따라서 민감한 정보는 정보 생산자가 신뢰할 수 있는 사람에게만 전달될 수 있어야하고, 신뢰할 수 있는 사람으로부터 정보를 제공받아야한다. 이러한 필요성으로 인해 사용자의 신뢰도를 평가할 수 있는 효율적인 방법이 필요하다. 본 논문에서는 서비스에서의 신뢰를 정의하며, 서비스의 기능을 활용하여 Trust Parameter를 만들고 사용자의 신뢰도를 평가할 수 있는 동적 사용자 신뢰도 평가 스킴을 제안한다. 그리고 제안한 신뢰도 평가 스킴에 대한 분석을 통해 사용자들의 신뢰도에 대한 신뢰 범위를 도출한다.

• 제어로봇시스템학회논문지
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• 제12권12호
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• pp.1241-1248
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• 2006

In high reliability systems for industrial network such as railway signal system, fieldbus protocols have been known to satisfy the real-time and fault tolerant requirements. But, the application of fieldbus has been limited due to the high cost of hardware and software, and the difficulty in interfacing with multi-vendor products. Therefore, as an alternative to fieldbus, the computer network technology, especially Ethernet(IEEE 802.3), is being adapted to the industrial network. In this paper, we propose a switched Ethernet based railway signal system because of its very promising prospect for industrial application due to the elimination of uncertainties in the network operation. In addition, we propose the redundancy architecture for the reliability of network components. More specifically, this paper presents an analytical performance evaluation of switched Ethernet for railway signal system, and shows experimental evaluation of redundancy architecture.

• 전자공학회논문지B
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• 제28B권10호
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• pp.807-821
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• 1991

A mulitpath MIN(Multistage Interconnection Network), CSMP(Chained Shuffle Multi-Path) network, is proposed, having fault-tolerance and dynamic reroutability. The number of stages and the number of links between adjacent stagges are the same as in single path MINs, so the overall hardware complexity is considerably reduced in comparison with other multipath MINs. The CSMP networks feature links between switches belonging to the same state, forming loops of switches. The network can tolerate multiple faults, up to (N/4)*(log$_2$N-1), having occured in any stages including the first and the last ones(N:NO. of input). To analyze reliability, terminal reliability (TR) and mean time to failure( MTTE) age given for the networks, and the TR figures are compared to those of other static and dynamic rerouting multipath MINs. Also the MTTE figures are compared. The performance of the proposed network with respect to its bandwidth (BW) and probability of acceptance(PA) is analyzed and is compared to that of other more complex multipath MINs. The cost efficiency analysis of reliability and performance shows that the network is more cost-effective than other previously proposed fault-tolerant multipath MINs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권9호
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• pp.3034-3055
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• 2014

Wireless Sensor Networks have extensively been utilized for ambient data collection from simple linear structures to dense tiered deployments. Issues related to optimal resource allocation still persist for simplistic deployments including linear and hierarchical networks. In this work, we investigate the case of dimensioning parameters for linear and tiered wireless sensor network deployments with notion of providing extended lifetime and reliable data delivery over extensive infrastructures. We provide a single consolidated reference for selection of intrinsic sensor network parameters like number of required nodes for deployment over specified area, network operational lifetime, data aggregation requirements, energy dissipation concerns and communication channel related signal reliability. The dimensioning parameters have been analyzed in a pipeline monitoring scenario using ZigBee communication platform and subsequently referred with analytical models to ensure the dimensioning process is reflected in real world deployment with minimum resource consumption and best network connectivity. Concerns over data aggregation and routing delay minimization have been discussed with possible solutions. Finally, we propose a node placement strategy based on a dynamic programming model for achieving reliable received signals and consistent application in structural health monitoring with multi hop and long distance connectivity.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.452-455
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• 1999

Genetic algorithm is well known as the efficient algorithm which can solve a difficult problem. Network design considering reliability is NP-hard problem with cost, distance, and volume. Therefore genetic algorithm is considered as a good method for this problem. This paper suggests the reliable network which can be constructed with minimum cost using genetic algorithm and the rank method based on reliability for improving the performance. This method shows more excellent than existing method and confirms the result through simulation.

• International Journal of Computer Science & Network Security
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• 제24권1호
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• pp.31-44
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• 2024

People have been using more energy in the last years. Several research studies were conducted to develop sustainable energy sources that can produce clean energy to fulfill our energy requirements. Using renewable energy sources helps to decrease the harm to the environment caused by conventional power plants. Choosing the right location and capacity for DG-RESs can greatly impact the performance of Radial Distribution Systems. It is beneficial to have a good and stable electrical power supply with low energy waste and high effectiveness because it improves the performance and reliability of the system. This research investigates the ideal location and size for solar and wind power systems, which are popular methods for producing clean electricity. A new artificial intelligent algorithm called Nutcracker Optimization Algorithm (NOA) is used to find the best solution in two common electrical systems named IEEE 33 and 69 bus systems to examine the improvement in the efficiency & reliability of power system network by reducing power losses, making voltage deviation smaller, and improving voltage stability. Finally, the NOA method is compared with another method called PSO and developed Hybrid Algorithm (NOA+PSO) to validate the proposed algorithm effectiveness and enhancement of both efficiency and reliability aspects.