• 제목/요약/키워드: ARL

검색결과 138건 처리시간 0.028초

선택적 이동평균(S-MA) 관리도의 ARL (The ARL of a Selectively Moving Average Control Chart)

  • 임태진
    • 품질경영학회지
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    • 제35권1호
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    • pp.24-34
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    • 2007
  • This paper investigates the average run length (ARL) of a selectively moving average (S-MA) control chart. The S-U chart is designed to detect shifts in the process mean. The basic idea of the S-MA chart is to accumulate previous samples selectively in order to increase the sensitivity. The ARL of the S-MA chart was shown to be monotone decreasing with respect to the decision length in a previous research [3]. This paper derives the steady-state ARL in a closed-form and shows that the monotone property is resulted from head-start assumption. The steady-state ARL is shown to be a sum of head-start ARL and an additional term. The statistical design procedure for the S-MA chart is revised according to this result. Sensitivity study shorts that the steady-state ARL performance is still better than the CUSUM chart or the Exponentially Weighted Moving Average (EWMA) chart.

자동상관인 공정에서 Special-Cause CUSUM 관리도의 ARL (Average Run Lengths of Special-Cause Control Charts for Autocorrelated Processes)

  • Sungwoon Choi
    • 산업경영시스템학회지
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    • 제18권36호
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    • pp.243-251
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    • 1995
  • 본 연구에서는 자동상관인 공정의 변화를 빠르게 탐지할 수 있는 Special-Cause CUSUM 관리도를 사용하여 다섯가지 시계열 모델에 대해 다음과 같은 연구를 수행한다. 첫째 ACF와 PACF로 파라미터에 따른 ARL의 변화를 쉽게 해석할 수 있는 방법과 둘째로 독립인 관측값에 적용하는 Hawkins(1992)의 ARL 간략계산법을 자동상관인 공정에서도 사용할 수 있는 기법을 제시하여 기존의 시뮬레이션을 이용한 ARL 계산법에 비해 빠르고도 정확한 값을 구한다. 끝으로 두가지 유형의 평균이동에 대한 ARL 변화를 각각 계산해 보아 그 효과를 비교분석 한다.

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일반화 기하분포를 이용한 ARL의 수정에 관한 연구 (A Study on the Alternative ARL Using Generalized Geometric Distribution)

  • 문명상
    • 품질경영학회지
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    • 제27권4호
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    • pp.143-152
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    • 1999
  • In Shewhart control chart, the average run length(ARL) is calculated using the mean of a conventional geometric distribution(CGD) assuming a sequence of identical and independent Bernoulli trials. In this, the success probability of CGB is the probability that any point exceeds the control limits. When the process is in-control state, there is no problem in the above assumption since the probability that any point exceeds the control limits does not change if the in-control state continues. However, if the out-of-control state begins and continues during the process, the probability of exceeding the control limits may take two forms. First, once the out-of-control state begins with exceeding probability p, it continues with the same exceeding probability p. Second, after the out-of-control state begins, the exceeding probabilities may very according to some pattern. In the first case, ARL is the mean of CGD with success probability p as usual. But in the second case, the assumption of a sequence of identical and independent Bernoulli trials is invalid and we can not use the mean of CGD as ARL. This paper concentrate on that point. By adopting one generalized binomial distribution(GBD) model that allows correlated Bernoulli trials, generalized geometric distribution(GGD) is defined and its mean is derived to find an alternative ARL when the process is in out-of-control state and the exceeding probabilities take the second form mentioned in the above. Small-scale simulation is performed to show how an alternative ARL works.

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Molecular Cloning and Characterization of Lysozyme II from Artogeia rapae and its Expression in Baculovirus-infected Insect Cells

  • Bang, In-Seok;Kang, Chang-Soo
    • Animal cells and systems
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    • 제11권2호
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    • pp.175-182
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    • 2007
  • The lysozyme II gene of cabbage butterfly Artogeia rapae was cloned from fat body of the larvae injected with E. coli and its nucleotide sequence was determined by the RACE-PCR. It has an open reading frame of 414 bp nucleotides corresponding to 138 amino acids including a signal sequence of 18 amino acids. The estimated molecular weight and the isoelectric point of the lysozyme II without the signal peptide were 13,649.38 Da and 9.11, respectively. The A. rapae lysozyme II (ARL II) showed the highest identity (81%) in the amino acid sequence to Manduca sexta lysozyme among other lepidopteran species. The two catalytic residues ($Glu^{32}$ and $Asp^{50}$) and the eight Cys residue motifs, which are highly conserved among other c-type lysozymes in invertebrates and vertebrates, are also completely conserved. A phylogenetic analysis based on amino acid sequences indicated that the ARL II was more closely related to M. sexta, Hyphantria cunea, Heliothis virescens, and Trichoplusia ni lysozymes. The ARL II gene was expressed in Spodoptera frugiperda 21 insect cells and the recombinant ARL II (rARL II) was purified from cell-conditioned media by cation exchange column chromatography and reverse phase FPLC. The purified rARL II was able to form a clear zone in lysoplate assay against Micrococcus luteus. The lytic activity was estimated to be 511.41 U/mg, 1.53 times higher than that of the chicken lysozyme. The optimum temperature for the lytic activity of the rARL II was $50^{\circ}C$, the temperature dependency of the absolute lytic activity of rARL II was higher than that of the chicken lysozyme at low temperatures under $65^{\circ}C$.

북미 대학의 한국학 장서 평가에 관한 연구: A 대학을 중심으로 (A Study on Evaluation of Korean Collection of North America: Focused on the A University)

  • 오경묵
    • 정보관리학회지
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    • 제25권4호
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    • pp.269-281
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    • 2008
  • 본 논문은 북미 대학에서 한국학 장서 구축의 역사가 오래된 대학을 대상으로 그동안 구축된 한국학장서의 현황 규모에 대한 적정성을 현장을 중심으로 객관적으로 조사 분석한 것이다. 장서와 이용자 그룹에 근거하여 ACRL 표준공식을 적용하여 분석하였고, ARL 중앙값을 산출하여 비교하였다. ACRL 기준에 따른 평가결과, 이 대학의 한국학 장서는 B 등급으로 평가되었고, ARL 비교치 결과에서도 비교 대상교 15개 중에서 중간정도에 그치는 것으로 나타나서, 한국학 장서의 꾸준한 증가를 통해 한국학교육과정 지원을 보다 충실히 해야 한다는 결론을 도출하게 되었다.

단방향 누적점수관리도의 설계 (A Design of One-Sided Cumulative Scored Control Chart)

  • 최인수;이윤동
    • 품질경영학회지
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    • 제26권3호
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    • pp.31-45
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    • 1998
  • This paper proposes a method of designing one-sided cumulative scored control charts to control the process mean with a normally distributed quality characteristic. The average run length(ARL) is obtained from the average sample number of sequential probability ratio test(SPRT) on trinomial distribution. Using the analogy between cumulative scored control chart and SPRT for trinomial observations, a procedure is presented to determine three control chart parameters; lower and u, pp.r scoring boundaries and action limit. The parameters are determined by minimizing the ARL when the process is out of control with prespecified ARL when the process is in control.

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Optimal Designs for Attribute Control Charts

  • Chung, Sung-Hee;Park, Sung-Hyun;Park, Jun-Oh
    • 한국통계학회:학술대회논문집
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    • 한국통계학회 2003년도 추계 학술발표회 논문집
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    • pp.97-103
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    • 2003
  • Shewhart-type control charts have historically been used for attribute data, though they have ARL biased property and even are unable to detect the improvement of a process with some process parameters. So far most efforts have been made to improve the performance of attribute control charts in terms of faster detection of special causes without increasing the rates of false alarm. In this paper, control limits are proposed that yield an ARL (nearly) unbiased chart for attributes. Optimal design is also proposed for attribute control charts under a natural sense of criterion.

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아토피피부염의 손상된 피부장벽에 대한 혼합오일의 회복 효과 (Recovery Effect of Blending Oil on Skin Barrier Damaged by Atopic Dermatitis)

  • 서영미
    • 동서간호학연구지
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    • 제20권1호
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    • pp.57-62
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    • 2014
  • Purpose: The purpose of this study was to evaluate the effect of a mixture of ARL oils, Agastache rugosa, Rosemarinu officinalis, and Lavandula angustifolia on atopic dermatitis (AD) model on NC/Nga mice. Methods: Twenty-four, 6 week-NC/Nga mice were assigned to a control group (C, n=8), an AD-induced group (E, n=8), and an ARL oil-treated group (E, n=8) that had two treatments per day for 6 days. Epidermis thickness, total amount of collagen and expression of TGF-${\beta}$ in the AD induced mice were measured. Results: The ARL oil-treated group showed a significantly decreased epidermis thickness, and a greater amount of collagen and expression of TGF-${\beta}$ compared with the AD-induced group. Conclusison: ARL oil may be a putative resources for care or treatment of AD in the view of nursing intervention.

추정된 모수를 사용한 CCC-r 관리도에서 관리상태의 성능 (The in-control performance of the CCC-r chart with estimated parameters)

  • 김재연;김민지;이재헌
    • 응용통계연구
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    • 제31권4호
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    • pp.485-495
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    • 2018
  • CCC-r 관리도는 고품질공정에서 공정불량률을 관리하는 경우 매우 효율적이라고 알려져 있다. 이 관리도를 사용할 때 관리상태의 공정모수는 일반적으로 알려져 있지 않기 때문에 제1국면의 표본을 추출하여 이를 추정해야 한다. 제2국면에서 관리도의 성능은 제1국면에서 추정한 모수와 관리한계에 영향을 받기 때문에, 추정 오차의 영향을 살펴보는 것은 중요하다. 이 논문에서는 일반적으로 많이 사용하는 평균런길이의 평균(average of average run length) 이외에 평균런길이의 표준편차(standard deviation of average run length)를 사용하여 CCC-r 관리도의 관리상태의 성능을 평가하였다. 그 결과 CCC-r 관리도에서 안정적인 관리상태의 성능을 유지하기 위해서는 이전에 권장하던 제1국면의 표본 크기보다 훨씬 더 큰 표본이 필요하다는 사실을 알 수 있었다.