• Proceedings of the Korean Society for Quality Management Conference
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• 1998.11a
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• pp.133-142
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• 1998

This paper is a brief review of the different procedures that are available for fitting theoretical distributions to data. The use of each technique is illustrated by reference to a distribution system which including the Pearson, Poission approximation of Gamma distribution and Burr functions. These functions can be used to calculate percent out of specification. Therefore, in this paper a new methods for estimating a measure of non-normal process capability for Gamma distributed variable data proposed using the percentage nonconforming. Process capability indices combines with the percentage nonconforming information can be used to evaluate more accurately process capability.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.52
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• pp.347-354
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• 1999

Statistical Process Control(SPC) which uses control charts is widely used to inspect and improve manufacturing process as a effective method. A parametric method is the most common in statistical process control. Shewhart chart was made under the assumption that measurements are independent and normal distribution. In practice, this assumption is often excluded, for example, in case of (equation omitted) chart, when the subgroup sample is small or correlation, it happens that measured data have bias or rejection of the normality test. A bootstrap method can be used in such a situation, which is calculated by resampling procedure without pre-distribution assumption. In this study, applying bootstrap percentile method to (equation omitted) chart, it is compared and evaluated standard process control limit with bootstrap percentile control limit. Also, under the normal and non-normal distributions, where parameter is 0.5, using computer simulation, it is compared standard parametric with bootstrap method which is used to decide process control limits in process quality.

• Journal of Korea Society of Industrial Information Systems
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• v.5 no.3
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• pp.77-86
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• 2000

The main objectives of this dissertation is to propose a forth generation index C for the case where the target value T is not equal to the midpoint of the specification limits (i.e. asymmetric tolerances), and show that this index is more sensitive compared to the standard PCI's in detacting small shifts of the process mean from the target value. In conclusion, in this dissertation , a new methods for estimating a measure of process capability for non-normally distributed variable data is proposed using the percentage nonconforming.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.371-377
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• 2002

In this paper, We consider some generalization of these five basic indices to cover non-normal distribution. The proposed generalizations are compared with the five basic indices. The results show that the proposed generalizations are more accurate than those basic indices and other generalization in measuring process capability. We compared an estimation methods by Clements with based on sample percentiles, WVM to calculate the proposed generalization as an example. The results indicated that Clements method is more accurate than percentile method, WVM in measuring process capability. But the calculations of percentile method are easy to understand, straightforward to apply, and show be valuable used for applications.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1999.04a
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• pp.46-46
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• 1999

• Journal of Korean Society for Quality Management
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• v.38 no.2
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• pp.171-179
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• 2010

Pearn et al.(2002) supposed the $C_{pp}$ multiple process performance analysis chart. This chart displays multiple processes with the process variation and process departure on one single chart. But, this chart can not display the distribution of the process variation and process departure and is inappropriate for processes with non-normal distributions. With bootstrapping method, we can display the distribution of the process variation and process departure on the $C_{pp}$ multiple process performance analysis chart.

• Journal of the Korean Statistical Society
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• v.7 no.1
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• pp.11-16
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• 1978

Bayesian procedures are in vogue to revise the parameter estimates of the forecasting model in the light of actual time series data. In this paper, we study the Bayes forecast for demand and the risk when (a) 'noise' and (b) mean demand rate in a constant process model have moderately non-normal probability distributions.

• Structural Engineering and Mechanics
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• v.81 no.4
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• pp.481-492
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• 2022

Cycloidal ball planetary transmission (CBPT) has many applications as precision reducer, such as precision machinery and automation drive systems etc. The traditional analytical model of CBPT cannot accurately describe the change of the normal force of meshing points, and thus cannot describe the precise transmission process of meshing pairs. In the paper, a method for deriving the normal force equation is put forward by using the non-linear relationship between force and deformation in elastic mechanics. The two-point contact analytical models of all the meshing pairs are established to obtain the micro-displacement analytical model of CBPT under axial pre-tightening. Then, the non-real-time two-point contact analytical models of all the meshing pairs are further constructed to obtain the normal force expression to determine the critical compression coefficients. Experimental investigations are performed to verify the analytical model using the critical compression coefficients.

• Journal of the Korea Management Engineers Society
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• v.23 no.4
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• pp.159-164
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• 2018

Human-machine serial systems must be normal in both systems. Though the failure of machine is irreducible by itself, the human errors are of recurring type. When the human performance is described quantitatively, non-homogeneous Poisson Process model of human errors can be developed. And the model parameters can be estimated by maximum likelihood estimation and numerical analysis method. System reliability is obtained by multiplying machine reliability by human reliability.

• Proceedings of the Safety Management and Science Conference
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• 2013.11a
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• pp.161-168
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• 2013

지난 몇 십년동안 전 세계적으로 제조기술 분야의 급속한 성장으로 대부분의 제조업에서 눈부실만한 품질향상과 생산성 극대화를 이루어 왔다. 하지만 현재 제조기술 분야는 새로운 문제에 직면하고 있다. 실제 현장에서 관리하고자하는 품질특성은 정규분포를 따르지 않는 경우가 많은데, 대부분의 통계적 공정관리기술체계가 정규분포를 기반으로 하고 있다는 것이다. 이러한 이유로 비정규 공정에서 극소불량관리, 미세변동관리에 대한 연구가 시급한 실정이다. 하지만 비정규 분포를 통계적으로만 해석하고 설계하기 위해서는 현실적으로 한계가 있으며, 경제적 설계의 접근방법이 또 하나의 좋은 대안이 될 수 있다. 본 논문에서는 비정규 공정에서 관리도의 경제적 설계를 위한 연구동향을 살펴보고 추후 연구방향에 대해 제시하고자 한다.