An EWMA Chart with Varying Sample Interval to Monitor Calibration Processes

Author(s):  
María Guadalupe Russell-Noriega ◽  
Enrique Villa-Diharce
Keyword(s):  
Author(s):  
Nasrullah Khan ◽  
Muhammad S. Nawaz ◽  
Rehan A. K. Sherwani ◽  
Muhammad Aslam

1990 ◽  
Vol 112 (1) ◽  
pp. 83-87 ◽  
Author(s):  
R. H. Fries ◽  
B. M. Coffey

Solution of rail vehicle dynamics models by means of numerical simulation has become more prevalent and more sophisticated in recent years. At the same time, analysts and designers are increasingly interested in the response of vehicles to random rail irregularities. The work described in this paper provides a convenient method to generate random vertical and crosslevel irregularities when their time histories are required as inputs to a numerical simulation. The solution begins with mathematical models of vertical and crosslevel power spectral densities (PSDs) representing PSDs of track classes 4, 5, and 6. The method implements state-space models of shape filters whose frequency response magnitude squared matches the desired PSDs. The shape filters give time histories possessing the proper spectral content when driven by white noise inputs. The state equations are solved directly under the assumption that the white noise inputs are constant between time steps. Thus, the state transition matrix and the forcing matrix are obtained in closed form. Some simulations require not only vertical and crosslevel alignments, but also the first and occasionally the second derivatives of these signals. To accommodate these requirements, the first and second derivatives of the signals are also generated. The responses of the random vertical and crosslevel generators depend upon vehicle speed, sample interval, and track class. They possess the desired PSDs over wide ranges of speed and sample interval. The paper includes a comparison between synthetic and measured spectral characteristics of class 4 track. The agreement is very good.


2004 ◽  
Vol 31 (4) ◽  
pp. 445-455 ◽  
Author(s):  
Petros Maravelakis ◽  
John Panaretos ◽  
Stelios Psarakis
Keyword(s):  

2004 ◽  
Vol 36 (5) ◽  
pp. 387-399 ◽  
Author(s):  
CHANGSOON PARK ◽  
JAEHEON LEE ◽  
YOUNGIL KIM

Production ◽  
2011 ◽  
Vol 21 (2) ◽  
pp. 217-222 ◽  
Author(s):  
Yang Su-Fen ◽  
Tsai Wen-Chi ◽  
Huang Tzee-Ming ◽  
Yang Chi-Chin ◽  
Cheng Smiley

In practice, sometimes the process data did not come from a known population distribution. So the commonly used Shewhart variables control charts are not suitable since their performance could not be properly evaluated. In this paper, we propose a new EWMA Control Chart based on a simple statistic to monitor the small mean shifts in the process with non-normal or unknown distributions. The sampling properties of the new monitoring statistic are explored and the average run lengths of the proposed chart are examined. Furthermore, an Arcsine EWMA Chart is proposed since the average run lengths of the Arcsine EWMA Chart are more reasonable than those of the new EWMA Chart. The Arcsine EWMA Chart is recommended if we are concerned with the proper values of the average run length.


2001 ◽  
Vol 33 (2) ◽  
pp. 223-233 ◽  
Author(s):  
Gemai Chen ◽  
Smiley W. Cheng ◽  
Hansheng Xie

2018 ◽  
Vol 16 (4) ◽  
pp. 439-458 ◽  
Author(s):  
Anan Tang ◽  
Philippe Castagliola ◽  
Jinsheng Sun ◽  
Xuelong Hu

2020 ◽  
Vol 43 (4) ◽  
pp. 365-372
Author(s):  
Saddam Akber Abbasi ◽  
Muhammad Abid ◽  
Muhammad Riaz ◽  
Hafiz Zafar Nazir

Blood ◽  
1964 ◽  
Vol 24 (6) ◽  
pp. 683-700 ◽  
Author(s):  
T. M. FLIEDNER ◽  
E. P. CRONKITE ◽  
S. Å. KILLMANN ◽  
V. P. BOND

Abstract 1. Following administration of H3-thymidine to 15 patients with a variety of hemopoietic conditions, the emergence and the pattern of labeling of neutrophilic granulocytes were studied in peripheral blood leukocytic concentrates. The hematologic diagnosis included five in which the hemopoiesis appeared to be in a steady state equilibrium at the time of study, three with various types of leukemia, one with lymphosarcoma, two with multiple myeloma, one with myelofibrosis, two with pernicious anemia (once before and once after therapy) and two with bacterial infections. 2. The emergence time of neutrophilic segmented granulocytes (time from H3-thymidine injection to the first appearance of labeled segmented forms in the peripheral blood) was found to vary in steady state equilibrium from 96 to 144 hours. It was shortened to 48 hours in two instances with bacterial infection. This was interpreted as indicating a faster than normal nuclear maturation with normal or delayed cytoplasmic maturation (dissociation in nuclear and cytoplasmic maturation). 3. The number of segments of neutrophilic granulocytes was found to be unrelated to cell age as had been hypothesized by Arneth many years ago. However, bandforms were found in the circulation about 24 hours earlier than segmented forms, suggesting that they are younger and that some are acceptable to the blood while others continue to mature to segmented forms. Pelgeroid cells with round or bilobed nuclei found in one case of subleukemic myelocytic leukemia were found to emerge simultaneously 132 hours after H3-thymidine injection. This suggests that both types are identical in their degree of maturation. Thus the cells with round nuclei are not band forms but result possibly from a delayed nuclear maturation. 4. In patients studied for at least 2 weeks, characteristic undulations of the labeling indices of the segmented granulocytes were found. If the sampling intervals were 24 hours, peaks were found 6 days apart, the second peak being about half of the labeling index of the first. If the sample interval was shorter, a finer structure was observed with undulations showing peak intervals of 2-3 days. Although the significance is obscure at present, the constancy of the findings suggest that there may be a constant input of cells with the index of labeling varying due to some synchrony of the precursor population(s). Alternative explanations are discussed.


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