• Communications for Statistical Applications and Methods
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• v.6 no.1
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• pp.89-98
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• 1999

In this paper we estimate the reliability of parallel system with two components. We assume that the strengths of these components follow bivariate exponential(BVE) models proposed by Marshall-Olkin(1967) Block-Basu(1974) Freund(1961) and Proschan-Sullo(1974) These two components are subjected to a normally distributed random stress which is independent of the strength of the components. If the strengths ($\textit{X}_1$, $\textit{X}_2$) are subjected to a stress($\textit{Y}$) then the system reliability ($\textit{R}$) is given by $\textit{R}=\textit{P}[\textit{Y} We present some numerical results and compare the bias and the mean square error of the maximum likelihood estimator and proposed estimators for a moderate sized samples when $(\textit{X}_1, \textit{X}_2)$ follow BVE of Marshall-Olkin.

• Communications for Statistical Applications and Methods
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• v.11 no.2
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• pp.381-397
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• 2004

The marginal likelihood has become an important tool for model selection in Bayesian analysis because it can be used to rank the models. We discuss the marginal likelihood for Poisson regression models that are potentially useful in small area estimation. Computation in these models is intensive and it requires an implementation of Markov chain Monte Carlo (MCMC) methods. Using importance sampling and multivariate density estimation, we demonstrate a computation of the marginal likelihood through an output analysis from an MCMC sampler.

• Communications for Statistical Applications and Methods
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• v.23 no.1
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• pp.57-70
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• 2016

Type-II progressive censoring is one of the censoring methods frequently used in clinical studies, reliability trials, quality control of products and industrial experiments. Sometimes in Type-II progressive censoring experiments, the failure rate is low so the waiting time to observe the $m^{th}$ failure will be very long; however, the experimenter may have to terminate the experiment before a predetermined time. In this article, if two generalized types of Type-II progressive censoring are reminded, we then make some changes in the removal method of Type-II progressive censoring such that without reducing the deduction quality, the termination time of the experiment decreases. This can be done with decreasing withdraws throughout the steps of the experiment with a special reasonable method. A simulation study is done and the results are tabulated at the end of this article for a comparison between introduced method and Type-II progressive censoring.

• Communications for Statistical Applications and Methods
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• v.17 no.1
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• pp.89-98
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• 2010

In this paper, a two-stage group sampling plan based on the time truncated life test is proposed for the Weibull distribution. The design parameters such as the number of groups and the acceptance number in each stage are determined by satisfying the producer's and consumer's risks simultaneously when the group size and the test duration are specified. The acceptable reliability level is expressed by the ratio of the true mean life to the specified life. It was demonstrated from the comparison with single-stage group sampling plans that the proposed plan can reduce the average sample number or improve the operating characteristics.

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.70-74
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• 2018

In order to ensure the flow of goods available and more flexible, reduce labor costs, many factories and industrial zones around the world are gradually moving to use automated solutions. One of them is to use Automated guided vehicles (AGV). Currently, there are a line tracing method as an AGV operating method, and a method of estimating the current position of the AGV and matching with a factory map and knowing the moving direction of the AGV. In this paper, we propose ceiling Light and guided line based moving direction estimation algorithm using multi-camera on the AGV in smart factory that can operate stable AGV by compensating the disadvantages of existing AGV operation method. The proposed algorithm is able to estimate its position and direction using a general - purpose camera instead of a sensor. Based on this, it can correct its movement error and estimate its own movement path.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.745-748
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• 1990

MMS (Manufacturing Message Specification) is a communications standard of MAP (Manufacturing Automation Protocol), which is a Network Protocol for Industrial Automation. In the environment of Mini-MAP, MMS is situated in the application layer and on the LLC (Logical Link Control) layer. In this paper, MMS software is implemented on the basis of ISO DIS 9506. The implemented software was tested with Token Passing Bus Network Interface Unit, which was designed in our laboratory and performs the actions of layer 1 and 2.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.398-402
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• 1987

In the process industries control & organization consist of interconnections on different levels. The process controls that run these industries are a collection of well-defined functions in the form of standard modules interconnected by a communication network. Real-Time(throughput, response time), operator communication, flexibility, back-up and recovery needs have distribute organization of both system hardware and software. Multi-level systems are aften advocated for controlling complex systems, such as, electric, water, oil, gas plants. In practice, these systems encompass computers and person with their various communication requirements and limitations. Hence, Careful mutual adaptation of computer communications and organizational structure is necessary. This paper concentrates on these interactions between process control and organization on the basis of industrial case studies.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.13 no.6
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• pp.370-479
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• 1988

This paper presents a microprogrammable sequential controller which realizes the sequential logic system with parallel sequences described by a GRAFCET. The proposed controller improves speed, flexibility, programming ease and the efficiency of controlled system by paralle sequencing capability. It is especially designed for complex high speed sequential contollers requiring large I/O capabilities, such as industrial process controller or power electronic conversion controller.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.13 no.6
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• pp.470-470
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• 1988

This paper presents a microprogrammable sequential controller which realizes the sequential logic system with parallel sequences described by a GRAFCET. The proposed controller improves speed, flexibility, programming ease and the efficiency of controlled system by paralle sequencing capability. It is especially designed for complex high speed sequential contollers requiring large I/O capabilities, such as industrial process controller or power electronic conversion controller.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1692-1699
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• 2016

This paper deals with the problem of time delay estimation using de-convolution. Two approaches, conjugate gradient method and the total lease square method have been presented to solve the de-convolution problem. Numerical simulation demonstrates the superior performance of the proposed methods over the conventional GCC based algorithms and FIR filter method.