• Journal of the Korean Data and Information Science Society
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• v.24 no.3
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• pp.465-475
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• 2013

Higher quality level is generally perceived by customers as improved performance by assigning a correspondingly higher satisfaction score. Usually, the quality level is measured by process capability indices. The index is used to determine whether a production process is capable of producing items within a specified tolerance. Some useful process capability indices $C_p$, $C_{pk}$ and $C_{pm}$ have been widely used in six sigma industries to assess process performance. Most evaluations on process capability indices focus on point estimates, which may result in unreliable assessments of process performance. It is necessary to investigate their asymptotic correlationship among process capability indices $\hat{C}_p$, $\hat{C}_{pk}$ and $\hat{C}_{pm}$. In this paper, we study their asymptotic correlationship for some process capability indices $\hat{C}_p$, $\hat{C}_{pk}$ and $\hat{C}_{pm}$ under the normal process.

• The Korean Journal of Applied Statistics
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• v.29 no.2
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• pp.301-308
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• 2016

The process capability index is used to determine whether a production process is capable of producing items within a specified tolerance. Some process capability indices $C_p$, $C_{pk}$ and $C_{pm}$ have been of particular interest as useful management tools for tracking process performance. Most evaluations on process capability indices focus on statistical estimation and test of hypothesis. It is necessary to investigate their asymptotic correlationship among basic estimators ${\hat{C}}_p$, ${\hat{C}}_{pk}$ and ${\hat{C}}_{pm}$ of process capability indices $C_p$, $C_{pk}$ and $C_{pm}$. In this paper, we study their asymptotic correlationship for three process capability indices ${\hat{C}}_p$, ${\hat{C}}_{pk}$ and ${\hat{C}}_{pm}$ under bivariate normal distribution BN(${\mu}_x,{\mu}_y,{\sigma}^2_x,{\sigma}^2_y,{\rho}$). With some nonnormal processes, the asymptotic correlation coefficient of any two respective process capability index estimators could be established.

• Proceedings of the Korean Society for Quality Management Conference
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• 1998.11a
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• pp.594-609
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• 1998

In this dissertation, a new process capability index $C_{psk}$ is introduced for non-normal process. The Pearson curve and the Johnson curve are selected for capability index calculation and data modeling the normal-based index $C_{psk}$ is used as the model for non-normal process. A significant result of this research find that the ranking of the seven indices, $C_p,\;C_{pk},\;C_{pm},\;C^{\ast}_{pm},\;C_{pmk},\;C_s,\;C_{psk}$ in terms of sensitivity to departure of the process median from the target value T=M from the most sensitive one up to the least sensitive are $C_{psk},\;C_{s},\;C_{pmk},\;C^{\ast}_{pm},\;C_{pm},\;C_{pk},\;C_p$. i.e, By the criteria adopted for evaluation of PCI's $C_{psk}$ is the most sensitive to the departure of the process median from target and $C_p$ is least

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.4
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• pp.109-115
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• 2013

Process Capability Index (PCI) is useful Statistical Process Control (SPC) tool that is measure of process diagnostic and assessment tools widely use in industrial field. It has advantage of easy to calculate and easy to use in the field. $C_p$ and $C_{pk}$ are traditional PCIs. These are only considers of process variation. These are not given information about the characteristic value does not match the target value of the process. Studies of this process capability index by many scholars actively for supplement of its disadvantage. These studies to evaluate the capability of situation of various field has presented a new process capability index. $C_{pm}$ is considers both the process variation and the process deviation from target value. And $C_{pm}{^+}$ is considers economic loss for the process deviation from target value. In this paper development of new process capability index that is Taguchi's quadratic loss function by applying the expected loss. And check the correlation between existing traditional process capability index ($C_{pk}$) and new one. Finally, we propose the criteria for classification about developed process capability index.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.548-560
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• 2018

This study was conducted to evaluate the effects of SCM on PM's capabilities and sustainable benefit sharing in leading global companies. To achieve this, statistical analyses were carried out through an empirical questionnaire survey of 426 PMs in SCM companies. The results showed that SCM commitment, vision and goal sharing have positive effects on PM's capabilities in leading global companies, boosting PM capability. Moreover, sustainable benefit sharing was improved along with SCM trust building, vision and goal sharing in global leading companies, supporting the usefulness of these variables. In contrast, SCM information sharing and trust building did not lead to significant acceleration of PM's capabilities, rejecting these variables. These findings indicate that SCM information sharing or trust building does not really help simple members to accelerate PM's capabilities.

• Journal of Digital Convergence
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• v.13 no.1
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• pp.367-373
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• 2015

The purpose of this study was to examine the effect of backward walking training on the balance capability(Functional Gait Assessment; FGA, Timed Up & Go Test; TUG) and gait performance(10 meter Walking Test; 10 mWT) of stroke patients. Eighteen with stroke patients were randomly allocated to an experimental and contral group of nine patients each. both groups received general neurorehabilitative physical therapy for 45 minutes per day 5 times per week during 4 weeks. The experimental group also performed additional backward walking training for 20 minutes per day 3 times per week during 4 weeks. There were signicantly increase by backward walking training in outcome of the balance capability from the FGA was increase from $17.67{\pm}1.00scores$ to $19.22{\pm}1.00scores$(p<.05), TUG was decrease from $26.45{\pm}1.37sec$ to $23.28{\pm}1.35sec$(p<.05) and 10 mWT was decreased from $21.74{\pm}1.35sec$ to $18.33{\pm}1.10sec$ (p<.05). These result suggest that backward walking training for stroke patients is effective in improving balance capability(FGA, TUG) and gait performance(10 mWT).

• Communications for Statistical Applications and Methods
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• v.8 no.3
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• pp.697-709
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• 2001

In this paper we study two vector-valued process capability indices $C_{p}$=($C_{px}$, $C_{py}$ ) and C/aub pm/=( $C_{pmx}$, $C_{pmy}$) considering process capability indices $C_{p}$ and $C_{pm}$ . First, two asymptotic distributions of plug-in estimators $C_{p}$=($C_{px}$, $C_{py}$ ) and $C_{pm}$ =) $C_{pmx}$, $C_{pmy}$) are derived.. With the asymptotic distributions, we propose asymptotic confidence regions for our indices. Next, obtaining the asymptotic distributions of two bootstrap estimators $C_{p}$=($C_{px}$, $C_{py}$ )and $C_{pm}$ =( $C_{pmx}$, $C_{pmy}$) with our bootstrap algorithm, we will provide the consistency of our bootstrap for statistical inference. Also, with the consistency of our bootstrap, we propose bootstrap asymptotic confidence regions for our indices. (no abstract, see full-text)see full-text)e full-text)

• Korean Journal of Human Ecology
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• v.19 no.4
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• pp.719-732
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• 2010

This study assessed knowledge-based environments for knowledge management in hospital dietetic departments. This study categorized the current knowledge management environment into routine habits, capability, culture and system. A questionnaire was conducted on dieticians in general hospitals with 400 beds in Seoul and Gyeong-in areas. Excluding responses with significant missing data, 160 usable questionnaires were analyzed by SPSS package programs for the study. The result of the study is summarized as follows. The average number of licensed beds in the hospitals was 717.5 and the average number of meals provided daily was 1,626.3. 53.2% of dieticians were aged between 26 and 35. Of the maximum score of 5 points, habits scored $3.65{\pm}.44$ points, capability scored $3.38{\pm}.44$ points, culture scored $3.21{\pm}.46$ points and system scored $2.77{\pm}.74$ points. Hospitals with a high ratio of occupied beds also had significantly higher points in capability, culture and system. The older the group the higher points it scored in habits and culture. The married group scored higher points in habits while the higher educated group scored higher points in habits and capability. The dietitians in charge of clinical nutrition scored higher points in habit, capability and culture while the higher salaried group scored higher points in habit, culture and capability. Therefore this study would provide useful information for the introduction of knowledge management in hospital dietetic departments.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.1
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• pp.106-114
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• 2019

Recently, the manufacturing process system in the industrial field has become more and more complex and has been influenced by many and various factors. Moreover, these factors have the dependent correlation rather than independent of each other. Therefore, the statistical analysis has been extended from the univariate method to the multivariate method. The process capability indices have been widely used as statistical tools to assess the manufacturing process performance. Especially, the multivariate process indices need to be enhanced with more useful information and extensive application in the recent industrial fields. The various multivariate process capability indices have been studying by many researchers in recent years. Hence, the purpose of the study is to compare the useful and various multivariate process capability indices through the simulation. Among them, we compare the useful models of several multivariate process capability indices such as $MC_{pm}$, $MC^+_{pm}$ and $MC_{pl}$. These multivariate process capability indices are incorporates both the process variation and the process deviation from target or consider the expected loss caused by the process deviation from target. Through the computational examples, we compare these process capability indices and discuss their usefulness and effectiveness.

• Journal of Korean Society for Quality Management
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• v.30 no.3
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• pp.66-78
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• 2002

Process capability indices are being used as indicators for measurements of process capability for SPC of quality assurance system in industries. In view of the enhancement of customer satisfaction, process capability indices in which loss functions are used to deal with the economic loss In the processes deviated from the target, are in an adequate representation of the customer's perception of quality In this connection, the loss function has become increasingly important in quality assurance. Taguchi uses a modified form of the quadratic loss function to demonstrate the need to consider the proximity to the target while assessing its quality. But this traditional quadratic loss function is inadequate to assessing the quality and quality improvement since different processes have different sets of economic consequences on the manufacturing, Thereby, a flexible approach to the development of the loss function needs to be desired. In this paper, we introduce an easily understood loss function, based on reflection of probability density function of the normal distribution. That is, the Reflected Normal Loss function can be adapted to an asymmetric loss as well as to a symmetric loss around the target. We propose that, instead of the process variation, a new capability index, CpI using the Reflected Normal Loss Function that can accurately reflect the losses associated with the process and a new capability index CpI Is compared with the classical indices as $C_{p}$ , $C_{pk}$, $C_{pm}$ and $C_{pm}$ $^{+}$.>.+/./.