• International Journal of Quality Innovation
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• 제3권2호
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• pp.74-83
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• 2002

Process capability indices as an important kind of indices are intended to provide single-number assessments of the inherent process capability to meet specification limits on quality characteristic(5) of interest. In this paper the condition for the application of process capability indices is analyzed. On the basis of process capability indices, dynamic process capability indices as a new kind of indices to show the current process capability are discussed and the condition for the application of dynamic process capability indices is exhibited. Comparison between process capability index and dynamic process capability index and comparison between $D_p$ and $D_pk$ are made and the conclusions provide the approach for process control. According to the requirement of process capability indices provided by customer, quality control based on process capability indices dynamic process capability indices is discussed.

• The Korean Journal of Ecology
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• 제21권6호
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• pp.759-770
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• 1998

biotic indices scoring with the benthic macroinvertebrates were assessed as pollution monitoring tools in the north branch of the Han River system, Korea. We investigated the temporal variability of water quality at unpolluted, moderately polluted and heavily polluted sites using several biotic indices and assessed appropriate biological monitoring indices for lotic systems in Korea. The following biotic and chemical indices were employed in order to compare their applicability to the lotic systems : Trent Biotic Index (TBI), Chandler's Biotic Index-Average Score per Taxon (CBI-ASPT), Modified Biological Monitoring Working Party Score System-Average Score per Taxon (BMWP-ASPT), Hilsenhoff's biotic Index (BI) and Family-level Biotic Index (FBI) models for biotic analyses and National Sanitation foundation's Water Quality Index (NSFWQI) and comprehensive Chemical Pollution Index (Pb/n) for chemical analyses of water quality. Index and score values were compared with each other and with 24 water chemistry parameters. All biotic indices were significantly auto-correlated (p<0.001) and BI and FBI/ROK among them were highly correlated (r=0.84). BI and BMWP-ASPT models were also highly correlated with NSFWQI, while TBI values showed high correlation with the Pb/n. The BI and BMWP-ASPT were highly correlated with the most water chemistry parameters. We conclude that the BI model, which includes indicator species and abundance of taxa, is best suited for the bioassessment of lotic systems in Korea. For rapid field-based assessments, FBI/ROK and BMWP-ASPT models are also appropriate.

• 한국조사연구학회지:조사연구
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• 제5권2호
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• pp.71-90
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• 2004

제품과 마찬가지로 통계의 품질은 국가의 경쟁력을 높이고 국가발전에 필수적이다. 통계청은 지난 2002년 처음으로 48개의 통계품질평가지표를 사용해서 통계청에서 생산한 12개의 통계에 대한 품질평가를 실시하였다. 그러나 주요 국제기구나 선진국들에 비해 통계품질향상을 위한 조직과 인력이 부족하고 통계품질지표도 충분치 않아서 정확한 평가와 올바른 통계품질을 향상시키는 정책을 수립하는데 어려움이 있다. 이에 본 연구에서는 현재 통계청에서 사용하고 있는 통계품질평가지표를 검토하고 주요 국제기구와 통계 선진국들의 다양한 통계품질평가지표들을 비교${\cdot}$분석하여 81개의 평가지표를 마련하였고 이들은 7개 차원으로 분류하였다. 또한 이들 지표의 필요성과 각 지표에서 평가할 내용들을 정리하였다. 이 지표는 차원별, 절차별로 분류할 수 있고 통계별로 필요에 따라 사용될 수 있다.

• 한국산학기술학회논문지
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• 제20권10호
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• pp.107-116
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• 2019

방위산업은 최근 방산수출과 연계하여 국가의 주력사업으로 대두되고 있다. 이를 위해 군수업체의 품질수준 조사는 방위산업 육성정책을 수립하는데 필수적이다. 군수품 생산업체 품질수준 조사는 군수품 생산 업체의 내부 품질관리 및 품질경영 시스템에 대한 조사 및 분석을 통해, 향후 군수품의 전반적인 품질 수준 제고를 위한 품질 정책 수립에 기여하기 위해 매 년 수행하고 있다. 과거에 사용 하였던 품질수준 측정 지표가 현재의 실태를 반영하는데 한계가 있었다. 따라서 품질 수준의 진단 모형과 측정 지표를 개선할 필요성이 제기 되었다. 본 논문은 타 기관 및 기업의 품질 수준 측정 지표의 사례를 조사하고, 기존에 국방 분야에서 실시되고 있는 다양한 평가지표 등을 분석하였다. 또한 과정 지표와 성과 지표의 연계성을 강화하여 군수품 생산업체의 품질수준을 객관적이고 직관적으로 표시될 수 있도록 개선하였다. 본 논문을 통해 제시된 측정 지표 및 모형은 향후 군수품 품질수준 조사에 활용될 것이다. 또한 군수품 품질수준 조사결과는 정부의 국방품질관리 정책을 보다 효과적으로 수립하는데 활용될 수 있을 것이다.

• Journal of Information Processing Systems
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• 제16권2호
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• pp.508-521
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• 2020

We compared a novel encoding Lempel-Ziv complexity (ELZC) with three common complexity algorithms i.e., approximate entropy (ApEn), sample entropy (SampEn), and classic Lempel-Ziv complexity (CLZC) so as to determine a satisfied complexity and its corresponding quality indices for assessing quality of multi-lead electrocardiogram (ECG). First, we calculated the aforementioned algorithms on six artificial time series in order to compare their performance in terms of discerning randomness and the inherent irregularity within time series. Then, for analyzing sensitivity of the algorithms to content level of different noises within the ECG, we investigated their change trend in five artificial synthetic noisy ECGs containing different noises at several signal noise ratios. Finally, three quality indices based on the ELZC of the multi-lead ECG were proposed to assess the quality of 862 real 12-lead ECGs from the MIT databases. The results showed the ELZC could discern randomness and the inherent irregularity within six artificial time series, and also reflect content level of different noises within five artificial synthetic ECGs. The results indicated the AUCs of three quality indices of the ELZC had statistical significance (>0.500). The ELZC and its corresponding three indices were more suitable for multi-lead ECG quality assessment than the other three algorithms.

• 산업경영시스템학회지
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• 제25권2호
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• pp.1-10
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• 2002

Process capability indices are widely used in industries and quality assurance system. In past years, process capability analysis have been used to characterize process performance on the basis of univariate quality characteristics. However, in actual manufacturing industrial, statistical process control (SPC) often entails characterizing or assessing processes or products based on more than one engineering specification or quality characteristic. Therefore, the analysis have to be required a multivariate statistical technique. This paper introduces to multivariate capability indices and then selects a multivariate process capability index incorporated both the process variation and the process deviation from target among these indices under the multivariate normal distribution. We propose a new multivariate capability index $MC_{pm}^+$ using quality loss function instead of the process variation and this index is compared with the proposed indices when quality characteristics are independent and dependent of each other.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2005년도 춘계학술대회
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• pp.503-521
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• 2005

Process capability indices are widely used in industries and quality assurance system. When designing the parameter on the multiple quality characteristics, there has been a study for optimization of problems, but there has been few former study on the possible conflicting phenomena in considertion of the correlations among the characteristics. To solve the issue on the optimal design for muliple quality characteristics, the study propose the expected loss function with cross-product terms among the characteristics and derived range of the coefficients of terms. Therefore, the analysis have to be required a multivariate statistical technique. This paper introduces to multivariate capability indices and then selects a multivariate process capability index incorporated both the process variation and the process deviation from target among these indices under the multivariate normal distribution. We propose a new multivariate capability index $MC_{pm}^{++}$ using quality loss function instead of the process variation and this index is compared with the proposed indices when quality characteristics are independent and dependent of each other,

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2004년도 추계학술대회
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• pp.69-79
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• 2004

Process capability indices are widely used in industries and quality assurance system. When designing the parameter on the multiple quality characteristics, there has been a study for optimization of problems, but there has been few former study on the possible conflicting phenomena in considertion of the correlations among the characteristics. To solve the issue on the optimal design for multiple quality characteristics, the study propose the expected loss function with cross-product terms among the characteristics and derived range of the coefficients of terms. Therefore, the analysis have to be required a multivariate statistical technique. This paper introduces to multivariate capability indices and then selects a multivariate process capability index incorporated both the process variation and the process deviation from target among these indices under the multivariate normal distribution. We propose a new multivariate capability index $MC_{pm}^{++}$ using quality loss function instead of the process variation and this index is compared with the proposed indices when quality characteristics are independent and dependent of each other.

• 품질경영학회지
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• 제26권1호
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• pp.88-98
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• 1998

Process capability indices are used to determine whether a production process is capable of producing items within a specified tolerance. Using conditional distribution, we study some process capability indices ${\hat{C}}_{Gp}$, ${\hat{C}}_{Gpk}$, ${\hat{C}}_{Gpm}$ under conjugate prior distribution. We consider some process capability indices with Gibbs sampling method. Also, we examine some small sample properties related to these estimaters by some simulations.

• 기술혁신학회지
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• 제21권3호
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• pp.1127-1154
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• 2018

본 연구는 특허의 질적 특성을 관측 가능한 특허의 인용지표로 설명함으로써 특허가치 추정모형에 기여하는 것을 목표로 한다. 본 연구는 기업, 대학, 연구소가 한국특허청에 출원한 특허를 대상으로 전후방 인용자료를 구축하였다. 특허의 원천측면을 반영하는 후방인용 지표들이 후속특허에 의한 활용측면을 반영하는 전방인용 특성들을 잘 설명하는 것으로 나타났다. 전방인방 지표와 후방인용 지표 간에 존재하는 함수관계는 특허가치에 대한 추정, 예측모형을 더 정교화하는데 기여할 것이다. 후방인용 지표들은 특허 자체가 갖는 기술범위를 잘 설명하는 것으로 나타났다. 기술협력의 일방에게 기술협력의 상대방이 누구인지도 중요하였다.