Manual for obscuration code with space station applications

The Obscuration Code, referred to as SHADOW, is a user-oriented computer code to determine the case shadow of an antenna in a complex environment onto the far zone sphere. The surrounding structure can be composed of multiple composite cone frustums and multiply sided flat plates. These structural pieces are ideal for modeling space station configurations. The means of describing the geometry input is compatible with the NEC-BASIC Scattering Code. In addition, an interactive mode of operation has been provided for DEC VAX computers. The first part of this document is a user's manual designed to give a description of the method used to obtain the shadow map, to provide an overall view of the operation of the computer code, to instruct a user in how to model structures, and to give examples of inputs and outputs. The second part is a code manual that details how to set up the interactive and non-interactive modes of the code and provides a listing and brief description of each of the subroutines

Bistatic scattering from a cone frustum

The bistatic scattering from a perfectly conducting cone frustum is investigated using the Geometrical Theory of Diffraction (GTD). The first-order GTD edge-diffraction solution has been extended by correcting for its failure in the specular region off the curved surface and in the rim-caustic regions of the endcaps. The corrections are accomplished by the use of transition functions which are developed and introduced into the diffraction coefficients. Theoretical results are verified in the principal plane by comparison with the moment method solution and experimental measurements. The resulting solution for the scattered fields is accurate, easy to apply, and fast to compute

SATCOM antenna siting study on P-3C aircraft, volume 1

The NEC-BSC (Basic Scattering Code) was used to study the performance of a SATCOM antenna on a P-3C aircraft. After plate cylinder fields are added to version 3.1 of the NEC-BSC, it is shown that the NEC-BSC can be used to accurately predict the performance of a SATCOM antenna system on a P-3C aircraft. The study illustrates that the NEC-BSC gives good results when compared with scale model measurements provided by Boeing and Lockheed

Automated Fuzz Testing of Applications Using D-Bus Communication System

Tato práce se zaobírá použitím metody fuzzingu na testování aplikací komunikujících přes systém D-Bus. První část je zaměřená na seznámení s pojmem fuzzing a na využití této metody při testování aplikací. Následuje popis systému D-Bus a jeho architektury. V druhé části se práce zaobírá vhodným způsobem, jakým by se daly pomocí metody fuzzingu testovat aplikace komunikující přes systém D-Bus. V rámci práce byl implementovaný nástroj na testování aplikací, které využívají tento systém na meziprocesovou komunikaci. Při implementaci tohoto nástroje byl kladen důraz na to, aby s ním bylo možné otestovat co největší spektrum aplikací. Testování proběhlo na třech vybraných aplikacích - GNOME Shell , IMSettings a Evince . Ve dvou ze tří zmíněných aplikacích ( GNOME Shell , IMSettings ) byly nalezeny chyby, které způsobily jejich pád. Implementovaný nástroj taktéž detekoval úniky paměti v aplikaci IMSettings .This thesis discusses use of the fuzzing for testing applications communicating through D-Bus system. The first part is focused on introducing the concept of the fuzzing and on use of this method when testing applications. Subsequently, there is a description of D-Bus system and its architecture. In the second part, the thesis deals with an appropriate way of using the fuzzing method for testing applications communicating through D-Bus system. A tool was implemented within this thesis for testing applications which use this system for interprocess communication. During implementation of the tool there was an effort to make it possible to test the greatest variety of applications. Testing took place on the three selected applications - GNOME Shell , IMSettings and Evince . In the two of these three applications ( GNOME Shell , IMSettings ) was found bugs which caused their crash. Implemented tool also detected memory leaks in IMSettings application.

Numerical evaluation of the incomplete airy functions and their application to high frequency scattering and diffraction

The incomplete Airy integrals serve as canonical functions for the uniform ray optical solutions to several high frequency scattering and diffraction problems that involve a class of integrals characterized by two stationary points that are arbitrarily close to one another or to an integration endpoint. Integrals of such analytical properties describe transition region phenomena associated with composite shadow boundaries. An efficient and accurate method for computing the incomplete Airy functions would make the solutions to such problems useful for engineering purposes. Here, a convergent series solution form for the incomplete Airy functions is derived. Asymptotic expansions involving several terms were also developed and serve as large argument approximations. The combination of the series solution form with the asymptotic formulae provides for an efficient and accurate computation of the incomplete Airy functions. Validation of accuracy is accomplished using direct numerical integration data

Near Zone: Basic scattering code user's manual with space station applications

The Electromagnetic Code - Basic Scattering Code, Version 3, is a user oriented computer code to analyze near and far zone patterns of antennas in the presence of scattering structures, to provide coupling between antennas in a complex environment, and to determine radiation hazard calculations at UHF and above. The analysis is based on uniform asymptotic techniques formulated in terms of the Uniform Geometrical Theory of Diffraction (UTD). Complicated structures can be simulated by arbitrarily oriented flat plates and an infinite ground plane that can be perfectly conducting or dielectric. Also, perfectly conducting finite elliptic cylinder, elliptic cone frustum sections, and finite composite ellipsoids can be used to model the superstructure of a ship, the body of a truck, and airplane, a satellite, etc. This manual gives special consideration to space station modeling applications. This is a user manual designed to give an overall view of the operation of the computer code, to instruct a user in how to model structures, and to show the validity of the code by comparing various computed results against measured and alternative calculations such as method of moments whenever available

Designing for the Dissonance: Community-engaged Field Experiences for Challenging Curricular Misconceptions of Place toward Localizing and Indigenizing Curricula within Elementary Teacher Education.

Harmful oversights remain in elementary social studies curricula which overlook or misrepresent minoritized communities. This dissertation explores designs for teacher education which address these oversights through community collaborations. This multi-manuscript dissertation is an empirical-conceptual inquiry design (Cochran-Smith & Lytle, 2009), as it is not purely empirical or conceptual research. This design allows for an independent discussion of each study, while interpreting phenomena across the three chapters. Acknowledging my positionality as a white female, in a predominantly white, female profession, I look to Indigenous and Black scholars, both locally and broadly, to inform my perspective and project design. Using a phenomenological lens and ethnographic approaches, I conducted two empirical studies within two different community-based field experiences through an elementary social studies methods course. Sociocultural considerations of space, socioecological considerations of place, and critical culturally sustaining and revitalizing pedagogy (McCarty & Lee, 2014) provide the theoretical frame for this series of investigations. Guidance from Decolonizing Methodologies (Tuhiwai-Smith, 2021), methods from the fields of S-STEP, Self-Study of Teacher Education Practices, and reflexive thematic analysis (Braun & Clarke, 2021), necessitated attention to self-reflexivity, improvement, and relationships. Researching from the positionality of a traditionally defined teacher educator, I hope to build upon collaborative research scholarship which expands who is considered a teacher educator. These studies investigate teaching practices through community and preservice teacher narratives, which critically explore places as a means of overcoming curricular misconceptions. Findings describe curricular possibilities and limitations, and the implications when these two phenomena clash, what I am conceptualizing as curricular dissonance. I provide evidence of this phenomena in the first two empirical chapters. In my third chapter, I conceptualize this phenomenon as a site for learning through field experiences which confront the tensions inherent in teacher education and curriculum studies, to engage scholars across both fields of research

Roll plane analysis of on-aircraft antennas

Roll plane radiation patterns of on-aircraft antennas are analyzed using high frequency solutions. Aircraft-antenna pattern performance in which the aircraft is modelled in its most basic form is presented. The fuselage is assumed to be a perfectly conducting elliptic cylinder with the antennas mounted near the top or bottom. The wings are simulated by arbitrarily many sided flat plates and the engines by circular cylinders. The patterns in each case are verified by measured results taken on simple models as well as scale models of actual aircraft

STUDY OF DRAG REDUCING POLYMERS AND MECHANISMS OF THEIR INTRAVASCULAR EFFECT

Blood-soluble drag reducing polymers (DRPs) have been shown to produce considerable beneficial effects on blood circulation, including an increase in tissue perfusion and tissue oxygenation and a decrease in vascular resistance, when injected in blood at minute concentrations in animal models of normal and especially pathological circulation. DRPs have potential applications in treating tissue hypoperfusion caused by cardiovascular disease, stroke, peripheral vascular disease, diabetes, and other illnesses. To help to translate this novel therapy from the lab bench to the clinic, standard tests need to be developed for characterization and efficacy testing of candidate polymers. Furthermore, elucidation of the mechanisms of the observed DRP effects on blood circulation is extremely important for their future medical applications. Finally, effective, biocompatible and stable polymers which can be easily produced in large quantities must be identified. In this work a sequence of tests was developed to characterize and assess efficacy of DRPs for possible use in treating circulatory disorders. This research study also provided a better understanding of mechanical degradation of DRPs, especially in the presence of blood cells or particles. It was discovered that an increase in particle concentration led to an increase in degradation rate, and that rigid particles caused an even higher degradation rate than deformable red blood cells (RBCs). Microfluidic studies in models of microvessels showed that DRPs prevented RBC movement from the walls of microchannels toward the center and lessened plasma skimming at bifurcations, delivering more RBCs to smaller branches and thus to capillaries. In vivo, this may lead to a reduction of the near-wall plasma layer, which would facilitate gas transport, increase local wall shear stress and promote vasodilation decreasing vascular resistance in microvessels. Three polymers, including an aloe vera derived polysaccharide (AVP), poly(N-vinyl formamide), and hyaluronic acid (HA), were evaluated and characterized as new drag reducers for potential clinical use and found to be very effective. HA and AVP were found to be the most resistant to mechanical degradation of the tested polymers. Finally, relaxation time and gyration radius were found to be the polymer's physical properties which best predicted their drag reducing effectiveness