Antonio Fernando Branco Costa

Bio: Antonio Fernando Branco Costa is an academic researcher from Sao Paulo State University. The author has contributed to research in topics: Chart & Control chart. The author has an hindex of 34, co-authored 105 publications receiving 3446 citations. Previous affiliations of Antonio Fernando Branco Costa include Technical University of Lisbon & University of São Paulo.

X̄ charts with variable sample size

Abstract: The usual practice in using a control chart to monitor a process is to take samples of size n from the process every h hours. This article considers the properties of the X chart when the size of each sample depends on what is observed in the preceding ..

Chloride penetration into concrete in marine environment—Part I: Main parameters affecting chloride penetration

Abstract: The durability of concrete structures exposed to marine environment depends mainly on the ability of concrete to resist to chloride ingress. This complex phenomenon depends on many parameters related to the concrete properties and to the micro-environmental characteristics. This paper presents the results of an experimental study where fifty four 1.0×0.5×0.12 m concrete panels were exposed to marine environment for three to five years. A study of three concrete mixes in five different exposure conditions was conducted and the results show that the chloride penetration is strongly dependent on both the concrete quality and the exposure conditions. Both the diffusion coefficientsD and the surface chloride concentrationCs derived from the chloride profiles show a clear time dependence. This effect has serious implications for long term predictions of chloride penetration, therefore if constant values ofD andCs are assumed gross errors can be made.

X̄ Chart with Variable Sample Size and Sampling Intervals

Abstract: Recent theoretical studies have shown that the X-bar chart with variable sampling intervals (VSI) and the X-bar chart with variable sample size (VSS) are quicker than the traditional X-bar chart in detecting shifts in the process. This article considers..

X̄ Charts with Variable Parameters

Abstract: Varying the parameters of the X chart has been explored extensively in recent years. In this paper, we extend the study of the X chart with variable parameters to include variable action limits. ...

Chloride penetration into concrete in marine environment-Part II: Prediction of long term chloride penetration

Abstract: The development of chloride penetration models is essential for the assessment of the service life of concrete structures exposed to marine environment. Simple models derived from Fick's second law of diffusion are at present the best way to predict the chloride penetration in practical situations. However these models need to be calibrated with experimental results. This paper presents an experimental study where the parameters used in the penetration model were calibrated to allow the prediction of long term chloride content in concrete. The results showed that both the concrete cover and concrete quality requirements stated in the present codes need to be increased so that an acceptable service life can be achieved.

The Design and Analysis of Experiments

Abstract: THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

Sampling: Design and Analysis

Abstract: In his seminal book, Shewhart (1931) makes no demand on the distribution of the characteristic to be plotted on a control chart. How then can we explain the idea that normality is, if not required, at least highly desirable? I believe that it has come about through the many statistical studies of control-chart behavior. If one is to study how a control chart behaves, it is necessary to relate it to some distribution. The obvious choice is the normal distribution because of its ubiquity as a satisfactory model. This is bolstered by the existence of the Central Limit Theorem.

Research Issues and Ideas in Statistical Process Control

Abstract: An overview is given of current research on control charting methods for process monitoring and improvement. A historical perspective and ideas for future research also are given. Research topics include: variable sample size and sampling interval met..