Inertial reference unit

Unit provides rate damping, linear velocity changes and angular position information to attitude control system during turns and motor burns

Gas flow environmental and heat transfer nonrotating 3D program

The experimental contract objective is to provide a complete set of benchmark quality data for the flow within a large rectangular turning duct. The data are to be used to evaluate and verify three-dimensional internal viscous flow models and computational codes. The analytical contract objective is to select such a computational code and define the capabilities of this code to predict the experimental results. Details of the proper code operation will be defined and improvements to the code modeling capabilities will be formulated

Relativistic precession of quantum elliptical states in the Coulomb potential

A special relativistic perturbation to non-relativistic quantum mechanics is shown to lead to the special relativistic prediction for the rate of precession for quantum states in the Coulomb potential. This behavior is shown using SO(4) coherent states as examples. These states are localized on Kepler ellipses and precess in the presence of a relativistic perturbation.Comment: 10 pages, 3 figures, submitted to Am.J.Phys, revised for style, improved figure

Low Cost Quality of Service Multicast Routing in High Speed Networks

Many of the services envisaged for high speed networks, such as B-ISDN/ATM, will support real-time applications with large numbers of users. Examples of these types of application range from those used by closed groups, such as private video meetings or conferences, where all participants must be known to the sender, to applications used by open groups, such as video lectures, where partcipants need not be known by the sender. These types of application will require high volumes of network resources in addition to the real-time delay constraints on data delivery. For these reasons, several multicast routing heuristics have been proposed to support both interactive and distribution multimedia services, in high speed networks. The objective of such heuristics is to minimise the multicast tree cost while maintaining a real-time bound on delay. Previous evaluation work has compared the relative average performance of some of these heuristics and concludes that they are generally efficient, although some perform better for small multicast groups and others perform better for larger groups. Firstly, we present a detailed analysis and evaluation of some of these heuristics which illustrates that in some situations their average performance is reversed; a heuristic that in general produces efficient solutions for small multicasts may sometimes produce a more efficient solution for a particular large multicast, in a specific network. Also, in a limited number of cases using Dijkstra's algorithm produces the best result. We conclude that the efficiency of a heuristic solution depends on the topology of both the network and the multicast, and that it is difficult to predict. Because of this unpredictability we propose the integration of two heuristics with Dijkstra's shortest path tree algorithm to produce a hybrid that consistently generates efficient multicast solutions for all possible multicast groups in any network. These heuristics are based on Dijkstra's algorithm which maintains acceptable time complexity for the hybrid, and they rarely produce inefficient solutions for the same network/multicast. The resulting performance attained is generally good and in the rare worst cases is that of the shortest path tree. The performance of our hybrid is supported by our evaluation results. Secondly, we examine the stability of multicast trees where multicast group membership is dynamic. We conclude that, in general, the more efficient the solution of a heuristic is, the less stable the multicast tree will be as multicast group membership changes. For this reason, while the hybrid solution we propose might be suitable for use with closed user group multicasts, which are likely to be stable, we need a different approach for open user group multicasting, where group membership may be highly volatile. We propose an extension to an existing heuristic that ensures multicast tree stability where multicast group membership is dynamic. Although this extension decreases the efficiency of the heuristics solutions, its performance is significantly better than that of the worst case, a shortest path tree. Finally, we consider how we might apply the hybrid and the extended heuristic in current and future multicast routing protocols for the Internet and for ATM Networks.

Structural and Contextual Frameworks: Distinguishing Literal from Metaphorical Depictions of Exaggerated Size

In 2016, the authors proposed the Contextual Framework and Structural Framework for understanding pictorial metaphors. These two dichotomous frameworks are especially useful for assessing the apprehension by viewers of pictorial devices that can be used either literally or metaphorically. One such pictorial device is exaggerated size—that is, depicting objects as being overly large. This pictorial device can be used metaphorically (e.g., to indicate importance) or literally (e.g., to depict a giant). We analyze three comic book covers from the Silver Age of American comic books using both frameworks to illustrate how observers distinguish metaphoric pictorial devices from literal ones

A Comment on "The Far Future of Exoplanet Direct Characterization" - the Case for Interstellar Space Probes

Following on from ideas presented in a recent paper by Schneider et al. (2010) on "The Far Future of Exoplanet Direct Characterization", I argue that they have exaggerated the technical obstacles to performing such 'direct characterization' by means of fast (order 0.1c) interstellar space probes. A brief summary of rapid interstellar spaceflight concepts that may be found in the literature is presented. I argue that the presence of interstellar dust grains, while certainly something which will need to be allowed for in interstellar vehicle design, is unlikely to be the kind of 'show stopper' suggested by Schneider et al. Astrobiology as a discipline would be a major beneficiary of developing an interstellar spaceflight capability, albeit in the longer term, and I argue that astrobiologists should keep an open mind to the possibilities.Comment: Accepted for publication in Astrobiolog

Being With Friends and the Potential for Binge Drinking During the First College Semester

In this prospective study, we assess the relationship between being with high school friends during the college transition and binge drinking. Across analyses (n = 489), the presence of high school friends during the college transition was associated with reduced binge drinking at the end of the first college semester among individuals at risk for this behavior because they drank in high school, associated alcohol use with the student role, or engaged in binge drinking at the beginning of the fall term. This is consistent with research linking social integration to behavioral regulation and suggests the presence of high school friends during the college transition serves as a source of social control at a juncture characterized by a reduction in normative constraint. Implications for practitioners seeking to assess new students\u27 risks for binge drinking and to more effectively meet the needs of vulnerable groups are discussed in relation to the study results

Individual and Society: Sociological Social Psychology

Unlike the few other texts for undergraduate sociological social psychology courses that present 3 distinct traditions (or faces ) ... Symbolic Interactionist (SI), Social Structure and Personality (SSP), and Group Processes and Structure (GPS) by topic alone, this text initially discusses these faces by research tradition, and emphasizes the different theoretical frameworks within which social psychological analyses are conducted. With this approach, the authors make clear the link between face of sociological social psychology, theory, and methodology. And students gain an appreciably better understanding of the field of sociological social psychology; how and why social psychologists trained in sociology ask particular kinds of questions; the types of research they are involved in; and how their findings have been, or can be, applied to contemporary societal patterns and problems. Great writing makes this approach successful and interesting for students, resulting in a richer, more powerful course experience. A website offers instructors high quality support material, written by the authors, which you will appreciate and value -- Provided by publisher