• Title/Summary/Keyword: c-index

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Better Confidence Limits for Process Capability Index $C_{pmk}$ under the assumption of Normal Process (정규분포 공정 가정하에서의 공정능력지수 $C_{pmk}$ 에 관한 효율적인 신뢰한계)

  • Cho Joong-Jae;Park Byoung-Sun;Park Hyo-il
    • Journal of Korean Society for Quality Management
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    • v.32 no.4
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    • pp.229-241
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    • 2004
  • Process capability index is used to determine whether a production process is capable of producing items within a specified tolerance. The index $C_{pmk}$ is the third generation process capability index. This index is more powerful than two useful indices $C_p$ and $C_{pk}$. Whether a process distribution is clearly normal or nonnormal, there may be some questions as to which any process index is valid or should even be calculated. As far as we know, yet there is no result for statistical inference with process capability index $C_{pmk}$. However, asymptotic method and bootstrap could be studied for good statistical inference. In this paper, we propose various bootstrap confidence limits for our process capability Index $C_{pmk}$. First, we derive bootstrap asymptotic distribution of plug-in estimator $C_{pmk}$ of our capability index $C_{pmk}$. And then we construct various bootstrap confidence limits of our capability index $C_{pmk}$ for more useful process capability analysis.

Better Bootstrap Confidence Intervals for Process Incapability Index $C_{pp}$

  • Cho, Joong-Jae;Han, Jeong-Hye;Lee, In-Pyo
    • Journal of the Korean Data and Information Science Society
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    • v.10 no.2
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    • pp.341-357
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    • 1999
  • Greenwich and Jahr-Schaffrath(1995) considered a new process incapability index(PII) $C_{pp}$, which modified the useful index $C^{\ast}_{pm}{$ for detecting assignable causes. The new index $C_{pp}$ provides an uncontaminated separation between information concerning the process accuracy and precision while this kind of information separation is not available with the $C^{\ast}_{pm}$ index. In this paper, we will study about the index $C_{pp}$ based on the bootstrap. First, we will prove the consistency of bootstrap deriving the bootstrap asymptotic distribution for our index $C_{pp}$. Moreover, with the consistency of bootstrap, we will construct six bootstrap confidence intervals and compare their performances. Some simulation results, comparison and analysis are provided. In particular, two STUD and ABC bootstrap methods perform significantly better.

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Significant (SiC) index of the 12-year-old child's permanent teeth caries experience (12세 아동의 우식경험영구치 Significant Caries(SiC) Index에 대한 조사 연구)

  • Choi, Seung-Hui;Sung, Jung-Hee;Lee, Cheon-Hee
    • Journal of Korean society of Dental Hygiene
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    • v.13 no.6
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    • pp.1041-1046
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    • 2013
  • Objectives : The purpose of the study is to investigate the significant(SiC) index of the 12 year old children's permanent teeth caries experience. A total of 428 children aged 12 years old were recruited from metropolitan city(215 children) and rural area(213 children) in this study. SiC index was obtained from DMFT index. Data were analyzed by gender, region, and DMFT. Methods : DMFT index and Sic index were analyzed and compared by pit and sealant fissure treatment, dental caries, gender, and areas. A total of 428 children aged 12 years old were recruited from metropolitan city(215 children) and rural area(213 children) in this study. Results : Boy students(6.73) tended to have a higher SiC index than girl students(7.84). There were significant differences(p<0.05). DMFT index in urban area was 2.59, and that in rural area was 3.35. In SiC index, rural children showed a higher index(7.77) than urban children(6.72).There existed a significance between DMFT index and SiC index(p<0.05). Conclusions : It is important to educate and to develop the oral disease prevention program for the high risk group children. This study showed the relationship between DMFT index and SiC index in 12 year old children in urban and rural areas.

A Study on Process Incapability Measure for Non-Normal Process: $C^*_{psk}$TEX> (비정규공정에 대한 비공정능력 측도에 관한 연구: $C^*_{psk}$)

  • 채규용;이상용
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.21 no.48
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    • pp.233-240
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    • 1998
  • Recently, Hong-Jun Kim et al. introduced an improved process incapability index $C^*_{psk}$ by the transformation of the $C_{psk}{\;}C^*_{psk}$. A simple transformation of $C_{psk}$, can be regard as a process incapability index, provides an uncontaminated separation between information concerning the process accuracy and precision while this kind of information separation is not available with the $C_{psk}$. By an identical conception, in this article a new process incapability index $C^*_{psk}$ for Non-Normal process can be proposed by the transformation of the process capability index $C^*_{psk}$. The motivation behind introduction of $C^*_{psk}$ is that process capability index $C^*_{psk}$ cannot give information of the process accuracy and precision. A significant result of this research that $C^*_{psk}$ for the case where the target value T is equal to the midpoint of the specification limits or not Is evaluated without respect to T. Accordingly, $C^*_({psk})$ will be propose a reasonable process incapability measure for Non-Normal process

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A Measure of Process Incapability Index (비공정능력지수의 측도에 관한 연구)

  • 김진수;김홍준;송서일
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.22 no.49
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    • pp.77-87
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    • 1999
  • A simple transformation of the $C^{*}$$_{pm}$, $C_{pp}$ can be regard as a process incapability index, provides an uncontaminated separation between information concerning the process accuracy and precision while this kind of information separation is not available with the $C^{*}$$_{pm}$. Recently, Kyung-seok Shin et. al. introduced an improved process incapability index $C^{*}$$_{pmk}$ by the transformation of the $C_{pmk}$. Accordingly, in this article process incapability index $C^{*}$$_{psk}$ will be proposed by the transformation of the $C_{psk}$. The motivation behind introduction of $C^{*}$$_{psk}$ is that $C_{psk}$ has failed to overcome is that it cannot distinguish process of high conforming output proportions from those of low conforming output proportions. Process incapability index $C^{*}$$_{psk}$ can identify a difference between two things by comparison on $C_{psk}$ and $C^{*}$$_{psk}$.EX>$_{psk}$.EX>$_{psk}$.

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A Study on the Relationship between the Physical Properties of Soil and the Compression Index of Soft Clay in Gyungnam Coastal Region (경남해안지역 연약점토의 토질특성과 압축지수와의 상관성에 관한 연구)

  • 장정욱;최성민;박춘식
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.13 no.4
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    • pp.282-289
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    • 2001
  • This study analyzed the relationship between the physical properties of soil and the compression index of the soft clay in Gyungnam coastal region. Tests of physical and mechanical properties of soil have been carried out under the undisturbed condition at 82 Gimhae, 18 Jinhae and 27 Geojespecimens. The result showed that Terzaghi & Peck's empirical equation of the compression index were not applicable. The compression index of soft clay in Gyungnam coastal region was correlated with the water contents, the liquid limit and the initial void ratio. Among these, the initial void ratio showed the highest correlation with the compression index of soft clay in Gyungnam coastal region and the relationship is shown in the following. (1) The compression index of soft clay in Gyungnam coastal region is represented as follows: $C_c=0.74(e_o-0.7$ (2) The relationship between compression index and the swelling index in Gyungnam coastal region is represented as follows: $C_s=(1/8-1/15)C_c$.

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Significant Caries(SiC) Index Based on 2009 Korea National Health and Nutrition Examination Survey (2009년 국민건강영양조사에 근거한 Significant Caries(SiC) Index)

  • Han, Ji-Hyoung;Ann, Eun-Sook
    • Journal of dental hygiene science
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    • v.11 no.3
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    • pp.229-234
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    • 2011
  • This study obtained DMFT index(9271 people) in population with more than 6 years old based on data of 2009 Korea National Health and Nutrition Examination Survey, and calculated SiC index(2,517 people) by classifying group with high risk, which is 1/3 in high rank out of it. The aim was to confirm existence of the group with high risk of dental caries, and was to emphasize necessity of preventive strategy for the group with high risk. Statistical analysis was carried out t-test by using STATA 11.0 program. 1. DMFT index accounted for 45.0%(4,174 people) for men and 55.0%(5,097 people) for women. SiC index stood at 2,517 people. Men accounted for 36.3%(914 people). Thus, women were larger with 64.7%(1,603 people). 2. Seeing the mean in DMFT index and SiC index, the more rise in age led to the bigger difference in the mean between two groups. Especially, the difference was shown more than 4 points on the average for 13 and 14 years old and more than double on the average from over 15 years. 3. As a result of comparing gender, DMFT index was higher in women than men from over 14 years old. SiC index wasn't significant. However, women were indicated to be 1 piece more than men at the age of 9 and 14. 4. As a result of comparing by region, both DMFT index and SiC index were indicated to be higher in the rural area for their over 60s. Seeing the above results, the group with high risk is showing the higher rate of experiencing dental caries than DMFT-index in the whole. Thus, the comprehensively & intensively preventive management seems to be likely needed on group with high risk.

On the Plug-in Estimator and its Asymptotic Distribution Results for Vector-Valued Process Capability Index Cpmk (2차원 벡터 공정능력지수 Cpmk의 추정량과 극한분포 이론에 관한 연구)

  • Cho, Joong-Jae;Park, Byoung-Sun
    • Communications for Statistical Applications and Methods
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    • v.18 no.3
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    • pp.377-389
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    • 2011
  • A higher quality level is generally perceived by customers as improved performance by assigning a correspondingly higher satisfaction score. The third generation index $C_{pmk}$ is more powerful than two useful indices $C_p$ and $C_{pk}$ that have been widely used in six sigma industries to assess process performance. In actual manufacturing industries, process capability analysis often entails characterizing or assessing processes or products based on more than one engineering specification or quality characteristic. Since these characteristics are related, it is a risky undertaking to represent the variation of even a univariate characteristic by a single index. Therefore, the desirability of using vector-valued process capability index(PCI) arises quite naturally. In this paper, we consider more powerful vector-valued process capability index $C_{pmk}$ = ($C_{pmkx}$, $C_{pmky}$)$^t$ that consider the univariate process capability index $C_{pmk}$. First, we examine the process capability index $C_{pmk}$ and plug-in estimator $\hat{C}_{pmk}$. In addition, we derive its asymptotic distribution and variance-covariance matrix $V_{pmk}$ for the vector valued process capability index $C_{pmk}$. Under the assumption of bivariate normal distribution, we study asymptotic confidence regions of our vector-valued process capability index $C_{pmk}$ = ($C_{pmkx}$, $C_{pmky}$)$^t$.

THE RANDI$\acute{C}$ INDEX OF SOME DENDRIMER NANOSTARS

  • Madanshekaf, Ali
    • Journal of applied mathematics & informatics
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    • v.29 no.5_6
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    • pp.1075-1080
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    • 2011
  • Among the numerous topological indices considered in chemical graph theory, only a few have been found noteworthy in practical application, Randi$\acute{c}$ index is one of them. The dendrimer nanostars is a synthesized molecule built up from branched unit called monomers. In this article, we compute the Randi$\acute{c}$ index of two types of polymer dendrimers and a fullerene dendrimer.

Relationship Between Compression Index and Swelling Index for Remolded Clays (교란점토의 압축지수 및 팽창지수의 관계에 대해서)

  • Park, Jong-Hwa;Tatsuya, Koumoto
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2002.10a
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    • pp.317-320
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    • 2002
  • The compression index, $C'_c$ and the swelling index, $C'_s$ which are obtained from the e-log p curve of the consolidation test, are used to calculate the consolidation settlement. In this research, $C'_c$ and the two new methods of $C'_s$ i.e. $C'_{s1}$, $C'_{sm}$ for remolded clays were examined with the $({\omega}_0-{\omega}_p)$ and $(e_0-e_p)$ which are satisfied with the condition and the type of soil. Moreover, the relationships of $C'_{s1}$, and $C'_{sm}$ versus $C'_c$ were obtained.

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