• Journal of Institute of Control, Robotics and Systems
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• v.15 no.9
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• pp.887-893
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• 2009

In this paper, a mask-panel alignment robot system is considered for IT industry applications. Two kinds of solutions are suggested which are required in constructing a control system for the alignment robot with actuation redundancy. First, the kinematic solution for the 4PPR parallel positioning mechanism is formulated for an arbitrary initial posture, which relates the mask-panel misalignment in the task space and the desired actuator displacements in the joint space. Secondly, in order to increase the stiffness of the control motion and also to avoid the mechanical lock which may happen due to the redundant actuation, a new synchronous control method is proposed which has the merit of coordinating joint control motions while not losing individual joint control performance. In addition, the engineering process to develop a visual alignment robot system is described with the results of experimental setup and GUI software. Finally, the experimental results demonstrate the effectiveness of the proposed alignment system control methodology and how much beneficial it will be in real industrial applications.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.2
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• pp.169-179
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• 2010

Satisfying the same probability of loss of control and essentially two fail operative performance with a triplex computer architecture requires a lot of modification of the conventional redundancy management design techniques, previously employed in quadruplex digital flight control computer. T-50 FCS for triplex redundancy management design applied an advanced digital flight control architecture with an I/O controller which is functionally independent of the digital computer to achieve the same reliability and special failure analysis and isolation schemes for fail operational goals with a triplex configuration. The analysis results indicated that the triplex flight control system is to satisfy the safety requirement utilizing the advanced flight control techniques and the system performance of the implemented flight control system was verified by failure mode effect test.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.567-570
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• 2014

The basic of a reliable service using a system and network is duplex configuration. There are a various duplex configuration for a system and network and we must have a performance indicator about how to use some redundancy. Then, we need analysis tool and method which analyze efficiently the performance about various duplex models. The tool that analyzing the performance and stability of the system and the network are a mathematical analysis method and simulation method. The mathematical analysis is a commonly used method, but high complexity system is not suitable for analysis methods and the simulation method has the problems which take a long time to understand in itself. Then, to overcome this problems, we propose the more simple method than used method for network analysis and we prove the efficiency by using the simple redundancy models.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.5
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• pp.1013-1027
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• 2011

In this paper we propose ATCS, a practical TCP protocol coding scheme based on network coding for satellite IP networks. The proposal is specially designed to enhance TCP performance over satellite networks. In our scheme, the source introduces a degree of redundancy and transmits a random linear combination of TCP packets. Since the redundant packets are utilized to mask packet loss over satellite links, the degree of redundancy is determined by the link error rates. Through a simple and effective method, ATCS estimates link error rates in real time and then dynamically adjusts the redundant factor. Consequently, ATCS is adaptable to a wide range of link error rates by coding TCP segments with a flexible redundancy factor. Furthermore, the scheme is compatible with traditional TCP variants. Simulation results indicate that the proposal improves TCP performance considerably.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1461-1466
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• 2004

Recently Domestic EMU's on board signal systems are gradually changed form Cab signal(Fix Block) to Distance-to-go. Interfaces with on board signal system, TCMS Redundancy structure is mainly required. This paper suggest Manaul/Automatic Driving based on TCMS-ATC interface and design of backup system which is operated by Stan-by Computer when one of it's Local Interface Unit(LIU) is out of oder. For the purpose of Precision Train Stop, Distance-to-go signal system require accuracy speed. Free-axle structure is required for this system This paper suggest Free-axle braking system that lack of brake-force is compensated by the distributed brake-force using TCMS. And one of braking system has out of order, compensation of brake-force for Free-axle system. Then we prove our design to Complete Car Test

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4A
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• pp.611-620
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• 2006

The composite two plate-girder bridges are generally defined as a non-redundant load path structure because the bridge can collapse if one of the two girders is seriously damaged by a fatigue crack. In this paper, a numerical study on the evaluation of the after-fracture redundancy of the composite two-girder bridges was accomplished. The evaluation has been performed on the simple and three-span continuous bridges with I-section cross beams which serve as transverse bracing, and with or without the bottom lateral bracing system. The load carrying capacities of the intact and damaged bridges with or without lateral bracing were evaluated from material and geometric nonlinear analysis, respectively and the redundancy was evaluated for each case. It was acknowledged from the analytical results that both simple and continuous intact two-girder bridges have sufficient redundancy even without lateral bracing, but it takes an important role to improve the redundancy of damaged bridges.

• The KIPS Transactions:PartA
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• v.13A no.5 s.102
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• pp.421-428
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• 2006

This paper proposes an integrated recovery approach applying retry and rollback techniques to recover the TMR failure. Combining the time redundancy techniques with W system is apparently effective to recover the TMR failure(or masked error) primarily caused by transient faults. These policies need fewer reconfigurations at the cost of extra time required for the time redundant schemes. The optimal numbers of retry and rollback to minimize the mean execution time of tasks are derived for the proposed method through computing the likelihoods of all possible states of the failed system. The effectiveness of the proposed method is validated through examining certain numerical examples and simulations conducted with a variety of parameters governing environmental characteristics.

• Journal of The Korea Institute of Healthcare Architecture
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• v.21 no.1
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• pp.37-46
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• 2015

Purpose : With a recently growing population of the disabled, the importance of creating the living environment for them has been emphasized, making the design guidelines to play more important role in this sense. This research aims to generalize the existing design guidelines for the housing for the disabled, diagnose their problems, and suggest a systematic and consistent milestone of the guidelines developed in the future. Method : The analysis objects of this research are 1910 categories of the design guidelines for the domestic housing for the disabled, and the research removed the redundancy and separated multi-complex categories. A total of 1424 independent categories were extracted, and been conducted content analysis from three aspects of redundancy, sub-categorization system and descriptive form based on the extracted categories. Results : Redundancy analysis figured out important characteristics by space. Moreover, the current guideline system can be integrated by analysis of sub-category system. Lastly, the research found that the guidelines need to be understood more easily and suggested under accurate criteria by analyzing the descriptive forms. Implication : This research holds significance as a fundamental data to improve the design guidelines for the disabled in the future, ultimately contributing to a better quality of life of the disabled.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.6
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• pp.595-601
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• 2009

A flight control system for high reliability consists of complicated redundant structures. This redundancy can improve fault tolerant characteristics of system. So, a system manager is able to choose a suitable structure using analyzed quantitative data of various redundant structures. In this paper, we analyzed redundant characteristics and reliability. We defined necessary mathematical model for analysis tool. Then we compose a reliability block diagram analysis tool applying such defined analysis model using Simulink blocks. Finally we verified the analysis tool using a commercial tool.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.1
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• pp.50-57
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• 2011

In this paper, we proposes a new load-sharing algorithm with a ATmega2560 based digital communication. Proposed algorithm is different from conventional analog method. The high speed communication digital control is performed. To apply the digital communication and real-time control for time-sharing token bus method, we implemented high efficient load-sharing and redundancy. Also this system make down the price by auto ID algorithm and system response is improved by controller's voltage and current integral value sharing. In parallel system prototype, each module have controller and performed load-sharing according to master module integral value. In this paper, we verify the validity of proposed algorithm using PSIM program and prototype.