Microwave Components

Contains reports on two research projects

Ferrite post in a rectangular wave guide

A thin circular ferrite post magnetized lengthwise is placed in a rectangular wave guide with its axis normal to the direction of propagation of the incident waves. The polarization is such that the electric vector is parallel to the post. The reflected and transmitted waves are calculated both with respect to their intensities and phases. The results are also applied to find the influence of a thin ferrite post upon the resonant frequency of a rectangular cavity

Sequential Bahadur Efficiency

The notion of Bahadur efficiency for test statistics is extended to the sequential case and illustrated in the specific context of testing one-sided hypotheses about a normal mean. An analog of Bahadur\u27s theorem on the asymptotic optimality of the likelihood ratio statistic is seen to hold in the normal case. Some possible definitions of attained level for a sequential experiment are considered

Microwave Components

Contains reports on three research projects

Statistical Inference After Model Selection

Conventional statistical inference requires that a model of how the data were generated be known before the data are analyzed. Yet in criminology, and in the social sciences more broadly, a variety of model selection procedures are routinely undertaken followed by statistical tests and confidence intervals computed for a “final” model. In this paper, we examine such practices and show how they are typically misguided. The parameters being estimated are no longer well defined, and post-model-selection sampling distributions are mixtures with properties that are very different from what is conventionally assumed. Confidence intervals and statistical tests do not perform as they should. We examine in some detail the specific mechanisms responsible. We also offer some suggestions for better practice and show though a criminal justice example using real data how proper statistical inference in principle may be obtained

Optical/Near-Infrared Observations of GRO J1744-28

We present results from a series of optical (g and r-band) and near-infrared (K'-band) observations of the region of the sky including the entire XTE and ROSAT error circles for the ``Bursting Pulsar'' GRO J1744-28. These data were taken with the Astrophysical Research Consortium's 3.5-m telescope at Apache Point Observatory and with the 2.2-m telescope at the European Southern Observatory. We see no new object, nor any significant brightening of any known object, in these error circles, with the exception of an object detected in our 8 February 1996 image. This object has already been proposed as a near-infrared counterpart to GRO J1744-28. While it is seen in only two of our ten 8 February frames, there is no evidence that this is an instrumental artifact, suggesting the possibility of near-infrared flares from GRO J1744-28, similar to those that have been reported from the Rapid Burster. The distance to the ``Bursting Pulsar'' must be more than 2 kpc, and we suggest that it is more than 7 kpc.Comment: 21 pages, 5 JPEG plates, 2 postscript figures. This paper will appear in the May 1, 1997 edition of the Astrophysical Journa

Completing the market orientation matrix: The impact of proactive competitor orientation on innovation and firm performance

The concept of market orientation comprises four components: customer and competitor orientations, each with a proactive and responsive dimension. Studies have considered both responsive and proactive customer orientation. Competitor orientation, however, has been investigated more narrowly. Research has focused specifically on its responsive dimension, a firm's posture of quickly responding to its competitors' actions and their offerings; but has largely disregarded proactive competitor orientation, a firm's posture towards altering the market's competitive behavior in its favor. This study investigates the role of responsive and proactive competitor orientation on influencing innovation and firm performance, as well as the mediating effects of technology and learning orientation. Utilizing a unique dataset that combines primary and time-lagged secondary data from 306 firms, we find that both responsive and proactive competitor orientation are observable drivers of performance in the market, but in notably different ways. Proactive competitor orientation drives innovation performance, directly and through technology orientation. Responsive competitor orientation, instead, enhances firm performance through learning orientation. By providing insights about the proactive side of competitor orientation, this study supplements and completes the so called “market orientation matrix”. This framework provides guidance for leaders to develop and manage a practical application of, and future research on market orientation

Properties of Bayes Sequential Tests

Consider the problem of sequentially testing composite, contiguous hypotheses where the risk function is a linear combination of the probability of error in the terminal decision and the expected sample size. Assume that the common boundary of the closures of the null and the alternative hypothesis is compact. Observations are independent and identically distributed. We study properties of Bayes tests. One property is the exponential boundedness of the stopping time. Another property is continuity of the risk functions. The continuity property is used to establish complete class theorems as opposed to the essentially complete class theorems in Brown, Cohen and Strawderman