Thesis (MS)--Montana State University--Bozeman, 2010. / Typescript. Chairperson, Graduate Committee: Joseph A. Shaw. Includes bibliographical references (leaves 74-77).

Thesis (M. Phil.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 307-319).

Lynx is a concept under study for prioritization in the 2020 Astrophysics Decadal Survey. Providing orders of magnitude increase in sensitivity over Chandra, Lynx will examine the first black holes and their galaxies, map the large-scale structure and galactic halos, and shed new light on the environments of young stars and their planetary systems. In order to meet the Lynx science goals, the telescope consists of a high-angular resolution optical assembly complemented by an instrument suite that may include a High Definition X-ray Imager, X-ray Microcalorimeter and an X-ray Grating Spectrometer. The telescope is integrated onto the spacecraft to form a comprehensive observatory concept. Progress on the formulation of the Lynx telescope and observatory configuration is reported in this paper.

A basket weaving technique for making radio continuum maps has been developed at the Hartebeesthoek Radio Astronomy Observatory (HartRAO). This data reduction technique significantly reduces scanning effects by using independent maps scanned in orthogonal directions. The observation and data analysis procedures that were developed are presented. The technique was used to map the supernova remnant MSH 15-52 at frequencies of 5000 MHz and 8500 MHz. The flux spectral index for this supernova remnant was found to be 0.83 ± 0.02 in this frequency range. Two regions (A and B) of the Galactic plane were observed at 8500 MHz with a resolution of 6'. Region A covered the 5°x5° area 47.5°< k 52.5°, Ibl < 2.5°, and region B was the 4.2°x3° area 320.4°< I <334.6°, Ibl < 1.5°. Far infrared observations at 60 !lm were used in conjunction with the radio maps to separate the thermal and non-thermal components of the radio emission. The technique can be used to map the Galactic plane at 8500 MHz using dual polarisation once the receiver at HartRAO has been upgraded. This would fulfil a need for a medium resolution, high frequency survey of the southern Galactic plane. / Adobe Acrobat Pro 9.4.6 / Adobe Acrobat 9.46 Paper Capture Plug-in

In a culturally diverse South Africa, the debate concerning whose history to commemorate, is an increasingly controvertial issue. In light of this, a refreshing opportunity for the celebration of a shared memory has been identified in the forgotten Mpumalanga mission station, Botshabelo. It is remembered as a place of harmony between different cultures, the natural and man-made landscape, this once self-sustainable, flourishing settlement that now stands abandoned and in a state of decay (Langhan, 2000:25). This dissertation research focuses on design within sensitive heritage environments at various scales, through acts of layering. At the urban scale, the research investigates the possible mediation between heritage conservation and development for a returning local community. At a more detailed scale, the project focuses on the rediscovery of Botshabelo’s cultural precinct through layering of the old fabric with new ritual. And finally, at the precinct vision’s climax, Fort Merensky (which overlooks the Botshabelo valley) forms the dissertation’s site of design focus. Finally, through the reinterpretation of Fort Merensky as a device for ‘hiding’ and ‘revealing’, a cumulative moment is formed by which a (figurative and physical) vantage point for the unlocking and celebration of Botshabelo’s meaningful landscape is enabled. The project intends to create an architectural device for the safekeeping, showcasing and testing of ideas that mark Botshabelo’s memory, learning from it as a model for the development of South African self-sustainable, creative communities. / In ‘n kultuurryke Suid-Afrika, is die debat rondom wie se erfenis behoort gedenk te word ‘n kontroversiele onderwerp. ‘n Verfrissende geleentheid om ‘n gedeelde herinnering te vier is geïdentifiseer in die vergete Mpumlanga sendingstate, Botshabelo. Onthou as ‘n plek van harmonie tussen verskillende kulture, die natuurlike- en mensgemaakte landskap, word hierdie eens self-volhoubare, bloeiende nedersetting vandag bevind in ‘n verlate en vervalle toestand (Langhan, 2000:25). Die verhandelingnavorsing fokus op die tema van ontwerp binne sensitiewe erfenisomgewings op verskillende skale deur middel van gelaagtheid. Op die stedelike skaal ondersoek die navorsing die moontlike bemiddeling tussen erfenisbewaring en ontwikkeling van ‘n terugkerende plaaslike gemeenskap. Op ‘n meer gedetailleerde skaal, fokus die projek op die herontdekking van Botshabelo se kulturele gebied deur die ou stof met nuwe ritueel te laai. As hierdie gebied se klimakspunt, word Fort Merensky wat oor die Botshabelo-vallei uitkyk, die terrein van ontwerpfokus vir die skripsie. Deur die herinterpretasie van Fort Merensky as ‘n toestel om te ‘versteek’ en ‘onthul’, word ‘n kumulatiewe oomblik geskep waardeur ‘n (figuurlike en letterlike) uitkykpunt vir die ontsluiting en viering van Botshabelo se betekenisvolle landskap moontlik gemaak. Die projek beoog om ‘n argitektoniese toestel te skep vir die bewaring, uitstalling en toetsing van die idees wat Botshabelo se verlede kenmerk en sodoende daaruit te leer as ‘n model vir die ontwikkeling van Suid-Afrikaanse self-volhoubare, kreatiewe gemeenskappe. / Mini Dissertation MArch(Prof)--University of Pretoria, 2018. / Architecture / MArch(Prof) / Unrestricted

Recently, community initiatives have emerged for the establishment of large-scale environmental observatories. Cyberinfrastructure is the backbone upon which these observatories will be built, and scientists' ability to access and use the data collected within observatories to address research questions will depend on the successful implementation of cyberinfrastructure. The research described in this dissertation advances the cyberinfrastructure available for supporting environmental observatories. This has been accomplished through both development of new cyberinfrastructure components as well as through the demonstration and application of existing tools, with a specific focus on point observations data. The cyberinfrastructure that was developed and deployed to support collection, management, analysis, and publication of data generated by an environmental sensor network in the Little Bear River environmental observatory test bed is described, as is the sensor network design and deployment. Results of several analyses that demonstrate how high-frequency data enable identification of trends and analysis of physical, chemical, and biological behavior that would be impossible using traditional, low-frequency monitoring data are presented. This dissertation also illustrates how the cyberinfrastructure components demonstrated in the Little Bear River test bed have been integrated into a data publication system that is now supporting a nationwide network of 11 environmental observatory test bed sites, as well as other research sites within and outside of the United States. Enhancements to the infrastructure for research and education that are enabled by this research are impacting a diverse community, including the national community of researchers involved with prospective Water and Environmental Research Systems (WATERS) Network environmental observatories as well as other observatory efforts, research watersheds, and test beds. The results of this research provide insight into and potential solutions for some of the bottlenecks associated with design and implementation of cyberinfrastructure for observatory support.

>Magister Scientiae - MSc / We are fast moving into an era where data will be the primary driving factor for discovering new unknown astronomical objects and also improving our understanding of the current rare astronomical objects. Wide field survey telescopes such as the Square Kilometer Array (SKA) and Vera C. Rubin observatory will be producing enormous amounts of data over short timescales. The Rubin observatory is expected to record ∼ 15 terabytes of data every night during its ten-year Legacy Survey of Space and Time (LSST), while the SKA will collect ∼100 petabytes of data per day. Fast, automated, and datadriven techniques, such as machine learning, are required to search for anomalies in these enormous datasets, as traditional techniques such as manual inspection will take months to fully exploit such datasets.

No description available.

One of the many challenges in radio astronomy is the ability to make accurate measurements quickly. In recent years engineers and astronomers have begun implementing phased array feeds (PAFs) as a way to negate the long observation times required by single antenna feeds. Unfortunately, large mutual coupling and other loss terms result in low sensitivity, restricting PAF usefulness in on dish observation. This thesis addresses several ways to reduce mutual coupling and maximize sensitivity for PAFs in radio astronomy. Antenna design of this magnitude requires accurate modeling capabilities. To this end, electromagnetic software models and low loss component designs are verified and validated with measured data. This process required the construction of a 50 Ω matched dipole and measurements on a network analyzer at Brigham Young University. The design and optimization of several single and dual polarization hexagonal grid arrays of 19 and 38 elements respectively are also described. Model figures of merit are compared with measurements taken on the 20-Meter dish at the National Radio Astronomy Observatory (NRAO) in Green Bank, WV and the 300 meter dish at the Arecibo Observatory in Arecibo, PR. Although some unexplained discrepancies exist between measured and model datasets, the dual pol cryocooled kite array described boasts the highest PAF sensitivity ever measured.