Space shuttle entry and landing navigation analysis

A navigation system for the entry phase of a Space Shuttle mission which is an aided-inertial system which uses a Kalman filter to mix IMU data with data derived from external navigation aids is evaluated. A drag pseudo-measurement used during radio blackout is treated as an additional external aid. A comprehensive truth model with 101 states is formulated and used to generate detailed error budgets at several significant time points -- end-of-blackout, start of final approach, over runway threshold, and touchdown. Sensitivity curves illustrating the effect of variations in the size of individual error sources on navigation accuracy are presented. The sensitivity of the navigation system performance to filter modifications is analyzed. The projected overall performance is shown in the form of time histories of position and velocity error components. The detailed results are summarized and interpreted, and suggestions are made concerning possible software improvements

Predation by Amphibians and Small Mammals on the Spruce Budworm (Lepidoptera: Tortricidae)

Stomach-content analyses of pitfall-trapped amphibians and small mammals showed that the eastern American toad, Bujo americanus americanus, and the wood frog, Rana sylvatica, preyed on late instars and moths of the spruce budworm, Choristoneura fumiferana. The spotted salamander, Ambystoma maculatum, and the masked shrew, Sorex cinereus, also preyed on late instars of the spruce budworm

Current Trends in Psychological Testing

Discussions about the adequacy of psychological measurement and assessment can quickly become controversial therefore; I expect some strong reaction to portions of this manuscript. Debates about the usefulness of criticism of psychological testing are longstanding: Even early psychologists such as Cattell and Jastrow disagreed on this issue. To be clear, I do not believe that use of contemporary tests should cease. I share the view that psychological tests often provide the fairest and most accurate method of making important decisions (K. R. Murphy & Davidshoffer, 1988, p. xii). My first purpose, then, is to provide a historical survey of relevant measurement and assessment concepts. I do not delve into intimate details and complexities, but trace measurement and assessment controversies over time and across psychological domains. This approach produced a broad picture of how psychological measurement and assessment have evolved. The first half contains descriptions and interpretations of issues that have been important over the lifespan of psychological science. My second goal is to expand discussion of the possible directions of measurement and assessment beyond those typically considered. The later half of this writing contains a summary of traditional approaches along with newer concepts and procedures. It is important to expand the scope of topics typically presented in psychological measurement and assessment texts, and I offer this as a complement to those works. At the same time, I am trying to present this material as simply as possible. Too much of measurement is incommunicable.because of its complexity. My goal has been to approach the problems of measurement and assessment from the perspective of psychological theory. I hope to reconnect measurement with substantive theory to create, better, richer, thicker descriptions from which to generate deeper conceptions and, most importantly, better questions (Snow & Wiley, 1991, p. 6). I have been surprised with the relative scarcity of sources describing the history of nonintellectual testing. Most measurement and assessment texts present a bit of history, and a few excellent book chapters and articles exist (Dahlstrom, 1985; Dawis, 1992). But I could find few sources that systematically examined the evolution of measurement and assessment to the extent that, for example, Boring (1957) did with experimental psychology. Perhaps the relative youth of psychological measurement—barely 100 years old—is a partial explanation. One consequence of this gap is that accounts of major concepts and procedures tend to be scattered throughout the literature. One of my goals has been to collect and reorganize seemingly unrelated material around long-standing measurement issues. At the same time, I expect that many readers will find portions of this repetitive or may find significant omissions

Small scale statistics of viscoelastic turbulence

The small scale statistics of homogeneous isotropic turbulence of dilute polymer solutions is investigated by means of direct numerical simulations of a simplified viscoelastic fluid model. It is found that polymers only partially suppress the turbulent cascade below the Lumley scale, leaving a remnant energy flux even for large elasticity. As a consequence, fluid acceleration in viscoelastic flows is reduced with respect to Newtonian turbulence, whereas its rescaled probability density is left unchanged. At large scales the velocity field is found to be unaffected by the presence of polymers.Comment: 7 pages, 4 figure

Inter-organisational coordination of H1N1 outbreak: data collection, and analyses of a pilot field study

Improving effectiveness in response to H1N1 outbreaks requires us to understand how different organisations within the outbreak coordination network work collectively to share information needed to operate at optimal level. Research for developing reliable framework for the collection of inter-organisational coordinated response data and its impact on decision-making and support system for disease outbreak is lacking to date. We introduce a pilot field study using social networks based approach to capture H1N1 inter-organisational coordination data by introducing qualitative questionnaire and quantitative survey, which resulted in discovering the hidden social networks of coordination. Here, we propose a schema that can be used to classify the quantitative data collection and preparation for further empirical analysis, and suggest that lessons learned from this can be applied to explore possible data collection and analysis for other types of natural and man made crises.postprin