Low-latency big data visualisation

Diese Arbeit hat sich zum Ziel gesetzt, Methoden aufzuzeigen, „Big-Data“-Archive zu organisieren und zentrale Elemente der enthaltenen Informationen zu visualisieren. Anhand von drei wissenschaftlichen Experimenten werde ich zwei „Big-Data“- Herausforderungen, Datenvolumen (Volume) und Heterogenität (Variety), untersuchen und eine Visualisierung im Browser präsentieren, die trotz reduzierter Datenrate die wesentliche Information in den Datensätzen enthält

Post-growth spectral tuning of InGaAs/GaAs quantum dot infrared photodetectors

Infrared photodetectors are essential in many industries and modern applications require devices with enhanced capabilities. High-performance detectors can be used for spectroscopy in medicine and environmental monitoring. Imaging scenarios include the identification of military targets and predicting equipment failure. These thermal imaging systems benefit from multicolour photodetectors. For example, some heat-seeking missiles incorporate two-colour HgCdTe arrays to discern target aircraft from decoy flares. Hyperspectral imaging describes the fusion of imaging and spectroscopy. These systems exhibit high spatial and spectral resolution, generally by dispersing different wavelengths onto a focal-plane array. Agricultural surveys, extraterrestrial exploration and medical procedures can all benefit from this powerful technique. High-end detectors in the mid-wavelength and long-wavelength infrared are usually made from HgCdTe alloys. These narrow-bandgap semiconductors exhibit favourable optoelectronic properties, however fabrication challenges lead to extravagant costs. In comparison, mature fabrication processes are available for III-V materials. Interband photodetectors made from these compounds are only sensitive at shorter infrared wavelengths. In recent years, intersubband devices have been developed for longer wavelengths and quantum well infrared photodetectors are now commercially available. Focal-plane arrays made from these structures are cheaper and the yield is better than with the HgCdTe technology. Quantum dot infrared photodetectors can also be fabricated from III-V materials. These architectures are inherently sensitive to normal-incidence radiation and have long carrier lifetimes, so they are expected to out-perform their quantum well counterparts. The devices studied here may be applicable to meteorology, atmospheric monitoring, molecular biology and medicine. High-quality quantum dots are normally grown by self-assembly and this restricts their size and composition. Hence, directly fabricating devices to operate at different wavelengths is an ongoing challenge. Post-growth techniques can instead be used to tailor the spectral response and two such approaches are considered in this thesis. Firstly, guided-mode resonances have been exploited in narrowband transmission filters. This design is agnostic to the detector technology and suitable for rugged environments. Germanium and calcium fluoride were selected for the dielectric layers and deposited films were thoroughly characterised. Guided-mode resonance filters based on photonic crystal slabs were integrated with quantum dot infrared photodetectors. The photoresponse of these devices was linearly tunable with the radius of the photonic crystal holes. These detectors are shown to be suitable for hyperspectral imaging with further optimisation of the device architectures. Intermixing shifts the response of InGaAs/GaAs quantum dot infrared photodetectors, so it is an effective approach to spectral tuning. Dielectric capping layers can be used to control the amount of intermixing and this allows multicolour detectors to be monolithically fabricated. In these studies, the compositional and thermomechanical properties of different dielectrics were measured. Preliminary intermixing experiments were performed on different heterostructures to extract the dominant physical processes. Ultimately, multicolour quantum dot infrared photodetectors were fabricated on a single sample. Silica was used to enhance intermixing through impurity-free vacancy disordering, whereas titania suppressed intermixing. Finally, the performance of each device was correlated with the properties of each dielectric. These detectors are found to be ideal for multispectral applications in the long-wavelength infrared band

Antenna near-field wave studies in magnetized plasmas as part of the optimization of auxiliary heating in fusion devicesAntenna near-field wave studies in magnetized plasmas as part of the optimization of auxiliary heating in fusion devices

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NASA Tech Briefs, July 2001

Topics include: special coverage sections on Data Acquisition, and sections on electronic components and systems, software, mechanics, machinery/automation, biomedical and a special section of Photonics Tech Briefs

Big Hole (41TV2161): Two Stratigraphically Isolated Middle Holocene Components in Travis County, Texas Volume I

During April and May 2006, an archeological team from the Cultural Resources Section of the Planning, Permitting and Licensing Practice of TRC Environmental Corporation’s (TRC) Austin office conducted geoarcheological documentation and data recovery excavations at prehistoric site 41TV2161 (CSJ: 0440-06-006). Investigations were restricted to a 70 centimeter (cm) thick target zone between ca. 220 and 290 cm below surface (bs) on the western side of site 41TV2161 – the Big Hole site in eastern Travis County, Texas. This cultural investigation was necessary under the requirements of Section 106 of the National Historic Preservation Act (NHPA), the implementing regulations of 36CRF Part 800 and the Antiquities Code of Texas (Texas Natural Resource Code, Title 9, Chapter 191 as amended) to recover a sample of the significant cultural materials prior to destruction by planned construction of State Highway 130 (SH 130). The latter by a private construction firm – Lone Star Infrastructure. This necessary data recovery was for Texas Department of Transportation (TxDOT), Environmental (ENV) Affairs Division under a Scientific Services Contract No. 577XXSA003 (Work Authorization No. 57701SA003). Over the years since the original award, multiple work authorizations between TxDOT and TRC were implemented and completed towards specific aspects of the analyses and reporting. The final analyses and report were conducted under contract 57-3XXSA004 (Work Authorization 57-311SA004). All work was under Texas Antiquities Committee Permit No. 4064 issued by the Texas Historical Commission (THC) to J. Michael Quigg. Initially, an archeological crew from Hicks & Company encountered site 41TV2161 during an intensive cultural resource inventory conducted south of Pearce Lane along the planned construction zone of SH 130 in the fall of 2005. Following the initial site discovery, archeologists expanded their investigations to the west across the SH 130 right-of-way, and completed excavation of 10 backhoe trenches, 13 shovel tests, and 11 test units at site 41TV2161. The investigations encountered at least seven buried cultural features and 1,034 artifacts, some in relatively good context. The survey and testing report to TxDOT presented their findings and recommendations (Campbell et al. 2006). The ENV Affairs Division of TxDOT and the THC reviewed the initial findings and recommendations, and determined site 41TV2161 was eligible for listing on the National Register of Historic Places and as State Antiquities Landmark as the proposed roadway development was to directly impact this important site and further excavations were required. Subsequently, TRC archeologists led by Paul Matchen (Project Archeologist) and J. Michael Quigg (Principal Investigator) initiated data recovery excavations through the mechanical-removal of between 220 and 250 cm of sediment from a 30-by-40 meter (m) block area (roughly 3,000 m3). This was conducted to allow hand-excavations to start just above the deeply buried, roughly 70 cm thick targeted zone of cultural material. Mechanical stripping by Lone Star Infrastructure staff created a large hole with an irregular bottom that varied between 220 and 260 cmbs. To locate specific areas to initiate hand-excavations within the mechanically stripped area, a geophysical survey that employed ground penetrating radar (GPR) was conducted by Tiffany Osburn then with Geo-Marine in Plano, Texas. Over a dozen electronic anomalies were detected through the GPR investigation. Following processing, data filtering, and assessment, Osburn identified and ranked the anomalies for investigation. The highest ranked anomalies (1 through 8) were thought to have the greatest potential to represent cultural features. Anomalies 1 through 6 were selected and targeted through hand-excavations of 1-by-1 m units that formed continuous excavation blocks of various sizes. Blocks were designated A, B, C, D, E, and F. The type, nature, quantity, and context of encountered cultural materials in each block led the direction and expansion of each excavation block as needed. In total, TRC archeologists hand-excavated 38.5 m3 (150 m2) from a vertically narrow target zone within this deep, multicomponent and stratified prehistoric site. Hand-excavation in the two largest Blocks, B and D (51 m2 and 62 m2 respectively), revealed two vertically separate cultural components between roughly 220 and 290 cmbs. The younger component was restricted to Block B and yielded a Bell/Andice point and point base, plus a complete Big Sandy point. These points were associated with at least eight small burned rock features, one cluster of ground stone tools, limited quantities of lithic debitage, few formal chipped and ground stone tools, and a rare vertebrate faunal assemblage. Roughly 20 to 25 cm below the Bell/Andice component in Block B and across Block D was a component identified by a single corner-notched Martindale dart point. This point was associated with a scattered burned rocks, three charcoal stained hearth features, scattered animal, bird, and fish bones, mussel shells, and less than a dozen formal chipped and ground stone tools. Both identified components contained cultural materials in good stratigraphic context with high spatial integrity. Significant, both were radiocarbon dated by multiple charcoal samples to a narrow 200-year period between 5250 and 5450 B.P. during the middle Holocene. With exception of the well-preserved faunal assemblages, perishable materials were poorly preserved in the moist silty clay loam. Charcoal lacked structure and was reduced to dark stains. Microfossils (e.g., phytoliths and starch gains) were present, although in very limited numbers and deteriorated conditions. The four much smaller Blocks (A, C, E, and F) yielded various quantities of cultural material and features, but these blocks also lacked sufficient charcoal dates and diagnostic artifacts Those artifacts and samples were left unassigned and analyzed separately from the Bell/Andice and Martindale components. The two well-defined components in Blocks B and D are the focus of this technical report. The components provide very significant data towards understanding rare and poorly understood hunter-gatherer populations during late stages of the Altithermal climate period. This final report builds upon the interim report submitted to TxDOT (Quigg et al. 2007) that briefly described the methods, excavations, preliminary findings, initial results from six feasibility studies, and proposed an initial research design for data analyses. Context and integrity of the cultural materials in the two identified components was excellent. This rare circumstance combined with detailed artifact analyses, solid documentation of their ages through multiple radiocarbon dates, and multidisciplinary approach to analyses, allowed significant insights and contributions concerning the two populations involved. Results provide a greater understanding of human behaviors during a rarely identified time in Texas Prehistory. The cultural materials and various collected samples were temporarily curated at TRC’s Austin laboratory. Following completion of analyses and acceptance of this final report, the artifacts, paper records, photographs, and electronic database were permanently curated at the Center for Archaeological Studies (CAS) at Texas State University in San Marcos

Biocultural perspectives on birth defects in medieval urban and rural English populations.

The biocultural and epidemiological approaches have been used as investigative methods by which to assess the prevalence of birth defects of the axial skeleton among five English Medieval population samples (Raunds Fumells, Northamptonshire; the hospital/almshouse of St James and St Mary Magdalene, Chichester, West Sussex; St Helen-on-the-Walls, York; Wharram Percy, East Yorkshire, and the Augustinian Friary cemetery, Hull, Humberside).The author hypothesises that Medieval urban populations produced offspring with higher frequencies of skeletal defects because they were subject to the adverse health-mediating effects of higher population density. These include poor quality, frequently overcrowded living conditions, poor sanitation, increased rates of disease threat and transmission, poorer quality food and drink due to pollution and adulteration, and greater levels of industrial-related air and water pollution. The author proposes that this response was a consequence of the impaired interaction between a population-wide compromised nutritional status and a co-existing weakened immune response. It is proposed that rural populations will express significantly lower frequencies of the same skeletal defects, as they are not subject to the same adverse environmental effects of population density and urban living conditions. The results support this hypothesis among the four populations derived from burial grounds associated with residential areas, whilst the Hull population expresses a rural pattern of defect prevalence, raising questions of possibly limited, exclusive access to burial at that site, available to non-urban dwellers. The author suggests that similar reproductive effects may be found today in populations undergoing demographic transition, for example, those experiencing the process of urbanisation in the developing world, or those migrating to the developed West. The author also shows how the results, when viewed alongside the medical literature, may indicate the presence of soft-tissue anomalies which are invisible to those working with dry bone. Keywords: urban, rural, medieval, birth defects, congenital, urbanisation, population density, biocultural, epidemiology, spine, cleft palate, skeleton, archaeology, palaeopathology

Proceedings of the 9th Arab Society for Computer Aided Architectural Design (ASCAAD) international conference 2021 (ASCAAD 2021): architecture in the age of disruptive technologies: transformation and challenges.

The ASCAAD 2021 conference theme is Architecture in the age of disruptive technologies: transformation and challenges. The theme addresses the gradual shift in computational design from prototypical morphogenetic-centered associations in the architectural discourse. This imminent shift of focus is increasingly stirring a debate in the architectural community and is provoking a much needed critical questioning of the role of computation in architecture as a sole embodiment and enactment of technical dimensions, into one that rather deliberately pursues and embraces the humanities as an ultimate aspiration

Reports to the President

A compilation of annual reports for the 1985-1986 academic year, including a report from the President of the Massachusetts Institute of Technology, as well as reports from the academic and administrative units of the Institute. The reports outline the year's goals, accomplishments, honors and awards, and future plans