Identificeren op grond van waarnemingen

This paper is an exposition of some elements of Wald's decision theory. Concepts like a priori distribution, decision function, loss function, risk, Bayes procedures, admissible procedures, minimax procedures, least favourable distribution are introduced all in connection with the problem of classification of observations into two given populations. The exact treatment of the procedures and their mutual relations are illustrated by numerical examples concerning univariate and multivariate normal populations. The extension towards the classification into more than two given populations concludes the paper.     

Interpolation and optimal linear prediction

This paper is concerned with the interpolation of spatially distributed observations of a quantitative phenomenon, sometimes referred to as kriging. This activity can be understood as a prediction procedure for values of random functions under stationarity assumptions in a polynomial linear regression context. After a heuristic and an exact derivation of the best linear unbiased prediction procedure (and the variance of prediction error) if the covariance function relating covariance between two possible observations to their mutual distance is known, follows the introduction of weaker assumptions admitting the definition of the variance only for increments of a certain order by a pseudoco–variance function. A particular related case is the so–called semivariogram for increments of order one. The prediction procedure turns out to be similar to that in the previous situation. The weaker assumptions allow an unbiased estimation of the unknown pseudocovahance function of polynomial form under restrictions imposed by Fourier transformation. Extension from point–wise observations or predictions to area or volume averages is touched upon.     

A different solution of a problem posed by Theil and Schweitzer

De vraag naar de nauwkeurigste (d.i. kleinste tweede moment) schatter van de restvariantie a² bij lineaire regressieanalyse met isomore onafhankelijke normaal verdeelde residuen wordt opnieuw beantwoord, maar longs vrijwel geheel andere weg dan door THEIL en SCHWEITZER [3] bewandeld. Het blijkt bovendien dat deling van de residuele som van kwadraten door het bijbehorende aantal vrijheids-graden + 2 niet alleen in de klasse der kwadratische funk ties der waarnemingen maar zelfs in de klasse van alle veelvouden van zuivere schattingen van σ² de nauwkeurigste is. Gebruik wordt gemaakt van de in een appendix bewezen stelling, dat de traditionele schatter van σ², waarbij de residuele som van kwadraten door het bijbehorend aantal vrijheidsgraden wordt gedeeld, de nauwkeurigste is onder alle zuivere schatters.     

Een algemene methode tot leemtevulling

An exposition of the missing plot technique often applied in analysis of variance is given in very general terms.
Non-orthogonality mostly implies heavy computations. If the scheme of observations is almost orthogonal this technique, however, supplies in a simple way unbiassed and efficient estimates of the expectation values which occur in a linear hypothesis underlying an analysis of variance. Moreover the correct residual sum of squares required for a test or a confidence interval estimation is obtained without difficulty.
A correct test of an effect or an interaction will be provided by two estimates, the first under the null-hypothesis, the second under the alternative hypothesis. In the case of non-orthogonality this may imply two separate applications of the discussed technique. The difference between the two residual sums of squares will be used for the numerator of a valid F-criterion.
The technique is illustrated by an example.     

The effects of supplier-to-buyer identification on operational performance—An empirical investigation of inter-organizational identification in automotive relationships

Over the past decade conceptual and empirical research in operations management has embraced the idea that collaborative supplier-buyer relationships are a source of competitive advantage for manufacturing firms. Anecdotal evidence from the Japanese and U.S. automotive industry and emerging research suggests that inter-organizational identification of suppliers with their buyers, termed supplier-to-buyer identification, is an unexplored factor of relational advantage. This study presents a model and empirical test that supplier-to-buyer identification fosters superior operational performance by enhancing trust, supplier relation-specific investments, and information exchange. Through a survey of 346 automotive supplier-buyer relationships, the findings show that supplier-to-buyer identification directly impacts supplier relationship-specific investments and information exchange, although most of the latter effect is mediated by trust. The findings also indicate that supplier relation-specific investments and information exchange play different but complementary roles in influencing operational performance. The results suggest new directions for supplier-buyer relationship research in operations management and important managerial implications.     

What really is alliance management capability and how does it impact alliance outcomes and success?

Strategy scholars have asserted that a firm's alliance capability provides competitive advantage. As interest in alliance capability has grown, we see two streams of research emerge that address different, but equally important, issues related to this subject: one stream that focuses on how alliance capability develops in firms, and a second stream that investigates what elements specifically constitute a firm's alliance capability. In recent literature, the question of how firms develop alliance capability has received greater attention than the question of what elements actually comprise it; therefore, in this study we address the latter issue in great depth. We do this by building on prior research and on our fieldwork, to conceptualize alliance management capability as a multidimensional construct that comprises three distinct but related aspects or skills to address the following aspects in managing a given individual alliance after it is up and running: coordination, communication, and bonding. We then test our conceptualization in a framework that also links this capability to relevant outcomes at the alliance and firm level. We use survey and secondary data from a large sample of interfirm relationships between software service providers and three major global software vendors. We find general empirical support for our conceptualization of alliance management capability and for its predictive validity in impacting certain alliance outcomes. Copyright © 2009 John Wiley & Sons, Ltd.