• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.30
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• pp.209-214
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• 1994

A consecutive k out of n failure lines with sink-source parts is a system of components in sequence such that the system fails whether some k consecutive components are all fail. Some object, be it a flow, is to be relayed from a source to a sink through a sequence of intermediate stations(components). Now care should be taken as to if the source and the sink are also considered components of the systems, i. e. , whether they serve the same function as the intermediate components (stations). Such systems are different from ordinary consecutive k- out of n failure lines by adding the on source and sink pole[6]. The main properties of the reliability by the optimal redundancy of consecutive k out of n failure lines are presented under this modification.

• Journal of Korean Society for Quality Management
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• v.21 no.1
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• pp.121-135
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• 1993

The derived expressions and computations of the system reliability in the consecutive k out of n failure structure with sink-source pole are discussed and a new simplified formulation to compute the reliability of consecutive k out of $n^*$ failure system is presented, and the relations with system reliability when the number of first consecutive falied components from source is greater than k are presented in this paper. The new simplified formulation is illustrated in the numerical experiments.

• YAKHAK HOEJI
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• v.20 no.3
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• pp.156-161
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• 1976

The salting in and salting out of Octoxynol, N.F., a nonionic polyoxyethylated surfactant by n-alkylamine hydrochlorides ws investigated by measuring their effect on the cloud point of the surfactant at various salt concentrations. The carbon number of the alkyl chain was varied from zero to twelve. Ammonium chloride, methylamine hydrochloride and ethylamine hydrochloride tended to salt out the surfactant, lowering its cloud point in proportion to the salt concentration. n-Ankylamine and n-butylamine hydrochlorides showed salting-out effect at low concentrations of the electrolyte, while their effects were leveled off and showed rather salting-in trend at higher concentrations of the electrolyte. These salting-in effect was ascribed to the formation of a hydrotropy of the n-alky lammonium cations with the surfactant. The higher homolog compounds of n-alkylamine hydrochlorides showed extraordinarily high salting-in effect at very low oncentrations of the electrolyte. These large salting-in effects were more drastic as the chain length was getting longer. These large increases of the cloud point of the surfactant were attributed to the formation of mixed micelles of n-alkylammonium cations with the polyoxyethylated surfactant.

• Proceedings of the Korean Reliability Society Conference
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• 2000.11a
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• pp.397-397
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• 2000

There exists an increasing need of study for generalized consecutive k-out-of-n systems. This paper demonstrates that a recursive formula for multi-dimensional consecutive k-out-of-n systems can be systematically developed by means of conventional structure function analysis. By taking advantage of notational convenience, the formulae expressed in the same recursive fashion just as the one dimensional consecutive k-out-of-n system. With the aids of the recursive formulae, not only the exact reliability of the system, but also the optimal arrangement of components is obtainable in a straightforward way.

• Journal of Korean Institute of Industrial Engineers
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• v.26 no.2
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• pp.128-135
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• 2000

This paper considers a consecutive k-out-of-n:F system when the failure of a component in the system induces higher failure rate of the preceding survivor. The reliability, mean time to failure(MTTF), and average failure number of a consecutive k-out-of-n:F system are obtained, when the failure of a component increases the failure rate of the survivor which is working just before the failed component. Then the optimal number of consecutive failed components to minimize this long run average cost rate can be obtained. An example is considered to calculate the reliability, MTTF and average failure number of the system. And two procedures that find the optimal number of consecutive failed components are studied. Then, various cases of system parameters are also studied.

• Journal of the Korean Chemical Society
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• v.24 no.1
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• pp.64-72
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• 1980

The synthesis of N-acrylylpyrrolidone has been carried out by the reaction of pyrrolidone and acrylyl chloride. The study on the copolymer of N-acrylylpyrrolidone and styrene is attempted.The copolymerization of N-acrylylpyrrolidone and styrene is carried out in benzene.Monomer reactivity ratio of N-acrylylpyrrolidone and styrene was calculated by Fineman and Ross equation. It is observed that the copolymer of N-acrylylpyrrolidone and styrene has random distributed acyl-lactam function on the vinyl polymer backbone.

• Journal of applied mathematics & informatics
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• v.8 no.1
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• pp.199-212
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• 2001

We consider a k-out-of-n system with repair under T-policy. Life time of each component is exponentially distributed with parameter $\lambda$. Server is called to the system after the elapse of T time units since his departure after completion of repair of all failed units in the previous cycle or until accumulation of n-k failed units, whichever occurs first. Service time is assumed to be exponential with rate ${\mu}$. T is also exponentially distributed with parameter ${\alpha}$. System state probabilities in finite time and long run are derived for (i) cold (ii) warm (iii) hot systems. Several characteristics of these systems are obtained. A control problem is also investigated and numerical illustrations are provided. It is proved that the expected profit to the system is concave in ${\alpha}$ and hence global maximum exists.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.8
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• pp.761-767
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• 2011

In this paper, to improve performance of spectrum sensing, we propose the method which can find optimal threshold based on power of PU(Primary User) signal. To find optimal threshold value, we will use mathematical method, and find threshold which can has lowest error probability. Each SU(Secondary User) use this threshold and All Su makes local decision. All Su Send local decision to FC(Fusion Center). In this paper we consider K-out-of-n rule to combining local decision. To make global decision value, FC find optimal n. In the FC. FC received local decision which has lowest error probability and using optimal n and these vaule. FC make global decision value. In this paper, to analysis performance proposed scheme, we simulate proposed scheme using matlab and compare with traditional OR Rule. As a result of simulation, we can know that preposed scheme can get a better performance than traditional OR rule.

• Proceedings of the Korean Reliability Society Conference
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• 2004.07a
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• pp.201-206
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• 2004

The linear consecutive-k-out-of-n:F system consists of n components ordered linearly and fails if and only if at least k consecutive components fail. We assume that the failure times of components are independent and identical exponentially distributed. This paper develops a model to calculate the expected cost per unit time of a linear consecutive-k-out-of-n:F system. The optimization problem to find the system structure parameter k to minimize the expected cost per unit time is considered.

• Journal of Korean Institute of Industrial Engineers
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• v.30 no.3
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• pp.250-260
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• 2004

This study considers a linear connected-(r,s)-out-of-(m,n):F lattice system whose components are ordered like the elements of a linear (m,n )-matrix. We assume that all components are in the state 1 (operating) or 0 (failed) and identical and s-independent. The system fails whenever at least one connected (r,s)-submatrix of failed components occurs. The purpose of this paper is to present an optimization scheme that aims at minimizing the expected cost per unit time. To find the optimal threshold of maintenance intervention, we use a genetic algorithm for the cost optimization procedure. The expected cost per unit time is obtained by Monte Carlo simulation. The sensitivity analysis to the different cost parameters has also been made.