• 대한산업공학회지
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• 제30권2호
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• pp.165-174
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• 2004

It is known that one out of every ten people walking down the street is left-handed. In daily living, left-handed people come across hardwares and facilities that were designed for right-handed people. Most tools, utensils, office equipment, home appliances, clothes, medical instruments, sporting goods, weapons, and public facilities are made for the right-handed person. Many left-handed people thus have trouble with living in our environments. In this study, 1,933 Korean male and female subjects aging from 10 to 82 were selected to investigate the various statistics about hand dominance and their employment characteristics of preferred hand in handling diverse products and facilities. The statistics showed that 5.6% were left-handed and 7.6% were ambidexter. There were strong tendency that left-handed people use more left hand when take action that force is required than when take exquisite action. Ambidexter and right-handed people use more right hand when they take exquisite action is required than when take action that force is required. It was found from these results that people use their hands differently depending on the hand dominance when they handle things, hence this should be considered in designing hand control devices.

• 대한산업공학회지
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• 제39권5호
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• pp.422-428
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• 2013

In many cases, an $\bar{X}$ control chart which is based on the performance variable is used in industrial fields. However, if the performance variable is too costly or impossible to measure and a less expensive surrogate variable is available, the process may be more efficiently controlled using surrogate variables. In this paper, we propose a model for the economic design of a VSI (Variable Sampling Interval) $\bar{X}$ control chart using a surrogate variable that is linearly correlated with the performance variable. The total average profit model is constructed, which involves the profit per cycle time, the cost of sampling and testing, the cost of detecting and eliminating an assignable cause, and the cost associated with production during out-of-control state. The VSI $\bar{X}$ control charts using surrogate variables are expected to be superior to the Shewhart FSI (Fixed Sampling Interval) $\bar{X}$ control charts using surrogate variables with respect to the expected profit per unit cycle time from economic viewpoint.

• 한국산업보건학회지
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• 제24권2호
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• pp.219-228
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• 2014

Objectives: The major objective of this study was to develop a tier 2 exposure model combining tier 1 exposure model estimates and worker monitoring data and suggesting narrower exposure ranges than tier 1 results. Methods: Bayesian statistics were used to develop a tier 2 exposure model as was done for the European Union (EU) tier 2 exposure models, for example Advanced REACH Tools (ART) and Stoffenmanager. Bayesian statistics required a prior and data to calculate the posterior results. In this model, tier 1 estimated serving as a prior and worker exposure monitoring data at the worksite of interest were entered as data. The calculation of Bayesian statistics requires integration over a range, which were performed using a Riemann sum algorithm. From the calculated exposure estimates, 95% range was extracted. These algorithm have been realized on Excel spreadsheet for convenience and easy access. Some fail-proof features such as locking the spreadsheet were added in order to prevent errors or miscalculations derived from careless usage of the file. Results: The tier 2 exposure model was successfully built on a separate Excel spreadsheet in the same file containing tier 1 exposure model. To utilize the model, exposure range needs to be estimated from tier 1 model and worker monitoring data, at least one input are required. Conclusions: The developed tier 2 exposure model can help industrial hygienists obtain a narrow range of worker exposure level to a chemical by reflecting a certain set of job characteristics.

• 산업경영시스템학회지
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• 제35권1호
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• pp.148-153
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• 2012

When the number of items of same type of industrial property is quite large, calculating depreciation for a group of such items may be more efficient than depreciating each item separately. Several different depreciation systems may be used for group depreciation. If the life of each vintage in an account are not estimated, then the BG procedure can be used; the BG procedure puts all vintages of the same type of property into a single broad group for depreciation purposes. In this case, only an estimate of the PASL and the net salvage ratio for all the property in the broad group is needed to calculate the depreciation charge.

• 품질경영학회지
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• 제25권3호
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• pp.62-73
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• 1997

Previous VSI control chart works have been done on quality variable whose distribution is normal. But there are many situations in which hte assumption of not a, pp.opriate. Also, in many industrial processes, the interest is to monitor the number of defectives. In this paper, we will take the existing properties of VSI control chart developed for the normal distribution and a, pp.y them to the np-chart based on the discrete binomial distribution. We will consider the CUSUM chart for the number of defectives. Here, the interesting object is to compute the VSI ATS for CUSUM control chart using Markov chain a, pp.oach and to compare FSI ATS and VSI ATS.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.107-112
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• 1998

In this paper, we propose a new paradigm (NEW_BP) to be capable of overcoming limitations of the traditional backpropagation(OLD_BP). NEW_BP is based on the method of conjugate gradients with the normalized direction vectors and computes step size through the linear search which may be characterized by order statistics and golden section. Simulation results showed that NEW_BP was definitely superior to both the stochastic OLD_BP and the deterministic OLD_BP in terms of accuracy and rate of convergence and might sumount the problem of local minima. Furthermore, they confirmed us that stagnant phenomenon of training in OLD_BP resulted from the limitations of its algorithm in itself and that unessential approaches would never cured it of this phenomenon.

• Communications for Statistical Applications and Methods
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• 제11권2호
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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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• 제17권1호
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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.

• 공학교육연구
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• 제19권2호
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• pp.53-59
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• 2016

Along with the industry growth, engineering colleges in Korea has have a quantitative growth. Many of the policy promotions and budgets for engineering colleges from the government are supported. And the various monitoring methods to verify their achievement have demanded. This paper deals with the construction of engineering educational statistics system in Korea. It named Korea Engineering Data Management System(K-EDMS). This system is based on the data mining tool and supports data-based decision making for an advanced engineering education service. This paper presents related researches of case studies. Then, we have designed K-EDMS, and constructed 157 cases for engineering colleges of the year 2014.

• 대한안전경영과학회지
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• 제10권1호
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• pp.1-10
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• 2008

With the development of the Korean economy, the number of arson fire has been radically increased and become a huge problem and issue in Korea Society for last several decades. This study is to establish the fire life safety strategy regarding the arson fire through researching domestic fire statistics and performing the computer simulation based on fire scenarios with cutting edge techniques and methods for fire characteristics and fire dynamic. In addition, to design the fire life safety strategy depending on the arson fire pattern, the flow and characteristics of fire flames and smoke are analyzed by the computer modeling.