• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.535-538
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• 1996

This paper presents the kinematic and dynamic analysis of parallel manipulators with actuation redundancy, obtained by replacing the passive joints of an existing parallel manipulator with the active ones. We develop the kinematic and dynamic models of a parallel manipulator with actuation redundancy. The multiplicity in selecting the controllable active joints among the increased number of active joints is considered in the modeling. Based on the derived models, we define the kinematic and dynamic manipulabilities of a parallel manipulator with actuation redundancy. The effect of the actuation, redundancy on the performance of parallel manipulators is analyzed in terms of kinematic and dynamic manipulabilities.

• Journal of the Korean Society of Systems Engineering
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• v.17 no.1
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• pp.1-10
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• 2021

In this paper we proposed the alternative analysis of reliability design using redundancy technique. First, we presented the process for establishing the reliability design alternative analysis process considering the active redundancy and the standby redundancy. and then, the case analysis of A driving equipment was performed in accordance with the reliability design alternative analysis process presented. In case the series reliability design result is not met with the reliability target value. so, the target item for redundancy design of A driving equipment were selected as items with a severity of two or higher. The redundancy design applied with active and standby redundancy techniques were analyzed using BlockSim software. As a result, it was analyzed that reliability design to active redundancy with one of two elements required for A driving equipment is the most efficient compared to the target value of reliability. The results of this study can be usefully used before the reliability design is performed.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.4
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• pp.11-17
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• 1996

In the case of redundancy control performed by a netowrk management system, it can not be ignored some delay of control time and break of control by failure of the system. This paper proposed a new method to improve the performacne of a redundancy control system interfaced to the network management system. At first, it produced the modelling of the total system and analyzed the functional relation of reliability and failure rate for a transmission system having an one-to-one active redundancy structure controlled by itself. After describing the loss rate of transmission data and the time required for the redundancy control process of the network management system when a failure is occurred, it proposed the new redundancy method of complex system control mode as an effective redundancy control method to improve reliability of a redundancy control system. Finally, it proved the effect by comparing the new result to the previous result.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.111-111
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• 2000

The research of network system, being used to reduce automotive wiring harness, is reaching to the development of by-wire system. It is by-wire system that apply IVN(In-Vehicle-Network) to steering, braking system, and it has the advantage of mass-decreasing, easy to diagnose fault and so on. But until now, many developed device can't satisfied with reliability that system have ever had. So redundancy of each network module, i.e., It is only way to make backup module. This paper researches development of network module and redundancy management of backup module when error occurred for implementation of brake-by-wire system.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.450-455
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• 2003

This paper is to discuss the hardware redundancy architecture of fault-tolerance system with using redundancy. Each architecture will be studied to implement fault-tolerance in classifying hardware redundancy architecture as passive, active and hybrid hardware redundancy. Therefore Fault-Masking and Fault-Detecting Techniques in each redundancy architecture is studied.

• IE interfaces
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• v.25 no.2
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• pp.153-162
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• 2012

The reliability is defined as a probability that a system will operate properly for a specified period of time under the design operating conditions without failure and it has been considered as one of the major design parameters in the field of industries. Reliability-Redundancy Optimization Problem(RROP) involves selec tion of components with multiple choices and redundancy levels for maximizing system reliability with constraints such as cost, weight, etc. However, in practice both active and cold standby redundancies may be used within a particular system design. Therefore, a redundancy strategy(active, cold standby) for each subsystem in order to maximize system reliability is considered in this study. Due to the nature of RROP, i.e. NP-hard problem, A Parallel Particle Swarm Optimization(PPSO) algorithm is proposed to solve the mathematical programming model and it gives consistently better quality solutions than existing studies for benchmark problems.

• International Journal of Railway
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• v.1 no.3
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• pp.89-93
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• 2008

Reliability of onboard power supply systems on rolling stock is a very important issue for the railway operator. While a failure of the HVAC supply results in a loss of comfort for the passengers, a failure of the supply for air compressors or for the traction cooling systems results in towing the train. This is, looking at the required availability of a train, not acceptable. An active redundancy concept for the onboard power supply maximizes the availability of the system. This paper describes such a system under the aspect of $\cdot$ Weight reduction $\cdot$ Continuous operation when changing from normal to redundant operation $\cdot$ Flexibility in train design.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.12
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• pp.2828-2835
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• 2015

In this paper, we analyse the effect of redundancy types and non-stop forwarding scheme on network service availability. We use stochastic reward net models as enabling modeling approach for the analytical evaluation. We first design stochastic reward nets for redundancy models with or without non-stop forwarding and then evaluate their availability using Stochastic Petri Net Package.

• The KIPS Transactions:PartA
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• v.16A no.4
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• pp.235-244
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• 2009

The mission-critical computer for air defense has to maintain its operation without any fault for a long mission time and is required to implement at low cost. Now the reliability of the mission critical-computer using Active Sparing Redundancy fault-tolerant technique is inferior to that of the computer using TMR technique. So in this paper are proposed Extended ASR(EASR) technique that provides higher reliability than that of the computer using TMR technique. The fault-tolerant performance of the implemented mission-critical computer is proven through reliability analysis and numbers of fault recovery test. Also, the reliability of the mission-critical computer using EASR technique is compared with those of computer using ASR and TMR techniques. EASR technique is very suitable to the mission-critical computer.

• 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.