ENBIS: European Network for Business and Industrial Statistics
Forgotten your password?
Not yet a member? Please register
ENBIS8 in Athens
21 – 25 September 2008 Abstract submission: 14 March – 11 August 2008The following abstracts have been accepted for this event:

Complex PCA as an Exploratory Tool for 3Dimensional Profiles
Authors: Bianca M. Colosimo, Massimo Pacella
Affiliation: Dipartimento di Meccanica, Politecnico di Milano, Milano, ITALY; Dipartimento di Ingegneria dell'Innovazione, Università del Salento, Lecce, ITALY
Primary area of focus / application:
Up to now, profile monitoring techniques have been constrained to situations in which the dependent variable is a scalar which can be modelled as a function of one or more independent variables via linear models or datareduction approaches as PCA. As a matter of fact, PCA has been demonstrated to be an excellent exploratory method for interpreting and modelling profiles in a scalar field of data, obtained from manufacturing processes (Colosimo and Pacella 2007).
However, when the quality of products is related to geometric tolerances, very often the profile cannot be simply modelled via a scalar variable, since the profile or curve lies in a 3dimensional space. Examples range from the simplest requirement of axial straightness to very complex curves in freeform geometric tolerance.
This paper explores problems arising when 3D curves has to be monitored over time proposing possible solutions. A real case dealing with the straightness of cylindrical components machined by turning is used as reference throughout the paper. In particular, an approach is discussed in which a generalization of PCA is used to model twodimensional vector observations (i.e., directional data). The method is based on an appropriate use of complex, rather than real numbers in the analysis. The socalled “complex PCA” is routinely used in the case of horizontal velocity components in geophysical measurements (such an approach was firstly proposed by Hardy and Walton, 1978). Our aim is to explore the use of complex PCA also for modelling 3D profiles obtained from manufacturing processes.
References
Colosimo B. M. and Pacella M., 2007. On the Use of Principal Component Analysis to Identify Systematic Patterns in Roundness Profiles. Quality and Reliability Engineering International, 23(6), 707725.
Hardy D. M. and Walton J. J., 1978. Principal Components of Vector Wind Measurements. Journal of Applied Meteorology, 17(8), 1153–1162. 
Measurement System Analysis  a computer aided research
Authors: Magdalena DIERING, MSc. Eng.; Edward PAJĄK, DSc PhD MSc. Eng., prof. PUT
Affiliation: Poznan University of Technology, Division of Production Management
Primary area of focus / application:
Manufacturing process engineers job involves continuously a necessity of making a decisions to keep the production process stable. To make correct decisions the process course must be regularly monitored for production quality and must be evaluated. Data of low quality can be the cause of making a wrong decisions about production process or products. To apply to MSA is as often as a requirement from demanding clients who consider that it is desirable that the given data must be a reliable source of information about the production process. In Polish enterprises MSA analyzing is still a rarity. Usually it is a result of low awareness of needs or even existing MSA methods or distrust to using them. Unconvinced of MSA benefits entrepreneurs may have an impression that conditions for carrying out a research, analysis and evaluation of measurement system, may interfere in a typical daily work of an organization. For a given research, one has to prepare parts, employees (participants of the experiment, a process engineer and a quality specialists), save up some place and, what is very timeconsuming  carry out an analysis of a given data sheet and prepare MSA report. These things are connected with extra time and in the days of strong market competition, which every enterprise has to face – time means money. An aid for that issue may be, represented by the authors of the article a computer application program.
The way to make a research of measurement system, its analysis and evaluation easier and faster that is more attractive for entrepreneurs is the purpose of this paper. The purpose of this paper is to describe one of MSA method for process engineers and quality managers as easy and useful instrument to estimate measurement system. 
A Bayesian Approach to Model Shifts in Poisson Data
Authors: Panagiotis Tsiamyrtzis and Douglas M. Hawkins
Affiliation: Dept. of Statistics, Athens University of Economics and Business
Primary area of focus / application:
Submitted at 15May2008 15:03 by Panagiotis Tsiamyrtzis
Accepted
Keywords:
Bayesian SPC by attributes, Change Point, Gamma mixture. 
Estimated Process Capability Indices and Impact on the Proportion of Nonconforming Output
Authors: Murat Caner Testik and Banu Yuksel Ozkaya
Affiliation: Hacettepe University, Dept. of Industrial Engineering, Ankara TURKEY
Primary area of focus / application:
Submitted at 15May2008 16:31 by Murat Caner Testik
Accepted

Double Generalized Linear Model Estimates in the Case of Unreplicated Designs with Dispersion Effects
Authors: Corinna Auer and Dr. Martina Erdbrügge
Affiliation: Technical University of Dortmund, Germany
Primary area of focus / application:
Submitted at 15May2008 19:25 by Corinna Auer
Accepted

Control Charts for the Logarithmic Distribution
Authors: Elisabeth Topalidou, Stelios Psarakis
Affiliation: Dept. of Statistics, Athens University of Economics and Business
Primary area of focus / application: