Indexing for efficient main memory processing

Ph.DDOCTOR OF PHILOSOPH

Integrating the UB-Tree into a Database System Kernel

Multidimensional access methods have shown high potential for significant performance improvements in various application domains

What Property Does

For centuries, scholars have wrestled with seemingly intractable problems about the nature of property. This Article offers a different approach. Instead of asking what property is, it asks what property does. And it argues that property protects people’s reliance on resources by moderating the pace of change. Modern scholarly accounts emphasize voluntary transactions as the source and purpose of reliance in property. Such “transactional reliance” implies strong, stable, and enduring rights. This Article argues that property law also reflects a very different source of reliance on resources, one that rises and falls simply with the passage of time. This new category of “evolutionary reliance” is at the heart of core property doctrines like adverse possession, waste, and the rule against perpetuities. Focusing on evolutionary reliance reveals a new vision of property, not as a bundle of sticks or a bare right to exclude, but instead as a nexus of competing and dynamic reliance interests that can change over time. This new vision has important conceptual and doctrinal consequences for common law doctrines and the Takings Clause, and it highlights the surprising dynamism and change in property

Mechanical behavior of fibrous root-inspired anchorage systems

Plant root-inspired geotechnics seeks to harness the principles of one of Earth’s most ubiquitous foundation elements to redesign or enhance conventional geotechnical infrastructure. In particular, the anchorage and material efficiency attributes of fibrous root systems are encapsulated in a novel root-inspired anchor that has the capability of surpassing conventional anchorage systems (e.g. tiebacks, tiedowns, plate and pile anchors) particularly in areas with weak soil or spatial constraints. The scope of this research fully exposes the application of the bio-inspired design process to the realization of root-inspired anchorage systems from 1) the reasoning behind the selection of fibrous root systems as a prime source of inspiration for sustainable, resilient anchor elements (e.g. plastic and thigmotropic adaptability properties, multifunctionality), to 2) the identification of the critical attributes of fibrous root systems to pullout behavior through testing of leek (Allium porrum) and spider (Chlorophytum comosum) plants, to 3) the design and fabrication of root-inspired anchor models, to 4) an extensive performance evaluation. More specifically, the root-inspired anchors are assessed in terms of their pullout behavior through a combination of analytical, experimental, and numerical analyses. The slip line method from plasticity theory is used as the basis to derive a solution for the prediction of plate anchor pullout capacity that was further modified to account for the more complex geometry of root-inspired anchors through mechanics-informed insights. Experimentally, a series of 1g pullout tests are performed to parametrically study the role of root-inspired anchor features (i.e. morphology, topology, material properties, and interface roughness) as well as soil properties (i.e. relative density, particle angularity, and particle size) on pullout behavior. Additionally, through a combination of x-ray CT imaging and digital image correlation (DIC), the formation and evolution of the soil failure surface during the uplift of a root-inspired anchor model is visualized and analyzed to connect the local soil kinematics to the global pullout response. With the finite volume method, the uplift process is simulated to validate experimental results and to extend the parametric study to a wider range of anchor and soil conditions. Finally a few considerations are highlighted concerning the upscale design, installation, and testing of these next generation anchor elements.Ph.D

GiD 2008. 4th Conference on advances and applications of GiD

The extended use of simulation programs has leaned on the advances in user-friendly interfaces and in the capability to generate meshes for any generic complex geometry. More than ten years of development have made Gid grow to become one of the more popular pre ans postprocessing systems at international level. The constant dialogue between the GiD development team and the users has guided the development of giD to cover the pre-post needs of many disciplines in science and engineering. Following gthis philosophy, the biannual GiD Conference has become an important forum for discussion and interchange of experiences among the GiD community. This monograph includes the contributions of the participants to the fourth edition of the GiD Conference held in the island of Ibiza from 8-9 May 2008

NASA thesaurus. Volume 1: Hierarchical Listing

There are over 17,000 postable terms and nearly 4,000 nonpostable terms approved for use in the NASA scientific and technical information system in the Hierarchical Listing of the NASA Thesaurus. The generic structure is presented for many terms. The broader term and narrower term relationships are shown in an indented fashion that illustrates the generic structure better than the more widely used BT and NT listings. Related terms are generously applied, thus enhancing the usefulness of the Hierarchical Listing. Greater access to the Hierarchical Listing may be achieved with the collateral use of Volume 2 - Access Vocabulary and Volume 3 - Definitions

The auditory cortex of the bat Phyllostomus discolor

The auditory cortex is the acoustically responsive part of the neocortex and represents the highest level of processing of the ascending auditory pathway. The experiments described in this thesis were designed to study the auditory cortex of the microchiropteran bat Phyllostomus discolor with both, simple and complex acoustic stimuli. During the experiments, different methods were used (e.g. psychophysics and neuroanatomy), but the main focus was laid on the electrophysiological examination of the auditory cortex. The first chapter covers a study that investigated the hearing range of P. discolor by measuring neural and behavioral audiograms in this species. This study shows that acoustic stimuli at frequencies between 4 and 100 kHz could elicit either a neuronal or behavioral response in P. discolor. Lowest thresholds were found in the high frequency range above 35 kHz indicating the high sensitivity of the auditory system of P. discolor to ultrasonic sounds as for example contained in echolocation calls. However, electrophysiologically and psychophysically determined hearing thresholds lay in the range of thresholds known for other bat species. The second chapter describes a study that determined the location, extend, and subdivision of the auditory cortex of P. discolor. The area that contained acoustically responsive neurons was laterally positioned at the caudal part of the neocortex. Within this area four major cortical subfields could be distinguished based on neuroanatomical and neurophysiological criteria. The two ventral fields were tonotopically organized and were assumed to belong to the “core” region of the auditory cortex. The posterior ventral field showed properties similar to that found in the primary auditory cortex of other mammals, whereas, the anterior ventral field seems to resemble the anterior auditory field of the mammalian auditory cortex. The two dorsally located subfields did not show a clear tonotopy, but contained neurons, which were mainly responsive to high frequencies above 45 kHz. As the dominant harmonics of the echolocation call of P. discolor cover this high frequency range, the anterior and posterior dorsal fields seem to be strongly involved in processing of information obtained from echolocation. The third and fourth chapter describes experiments that investigated the cortical processing of sound parameters relevant for echolocation: echo roughness and acoustic motion. Echo roughness as a measure for the temporal envelope fluctuation of a signal is especially important for the discrimination of complex targets like trees and bushes. Broad leaved trees produce echoes with a higher degree of roughness compared to small leafed trees, e.g. conifers. The neurophysiological experiment described in chapter three revealed a population of cortical neurons in the anterior part of the auditory cortex, which encoded echo roughness in their response rate. The response of these neurons could be correlated to the behaviorally measured discrimination performance of P. discolor. In the experiment described in chapter four, pairs of pure tones were used to simulate either echoes from an object moving in azimuth or echoes from a stationary object encountered by a bat during approach. In the posterior dorsal field of the auditory cortex of P. discolor a population of motion sensitive neurons was found, which showed strong response facilitation to dynamic stimuli in contrast to static stimulation. In a subset of motion sensitive neurons the dynamic azimuthal response range was focused to small areas in the frontal field at short temporal intervals between the two components of the dynamic stimuli. The response of these neurons might be important for the tracking of targets during an approach by the bat. The results presented in this thesis reveal that the auditory cortex of P. discolor is functionally parcellated into at least four different fields. This parcellation seems to reflect the segregated processing of behaviorally and ecologically important echo parameters within specialized areas of the auditory cortex

NASA Thesaurus. Volume 1: Hierarchical listing

There are 16,713 postable terms and 3,716 nonpostable terms approved for use in the NASA scientific and technical information system in the Hierarchical Listing of the NASA Thesaurus. The generic structure is presented for many terms. The broader term and narrower term relationships are shown in an indented fashion that illustrates the generic structure better than the more widely used BT and NT listings. Related terms are generously applied, thus enhancing the usefulness of the Hierarchical Listing. Greater access to the Hierarchical Listing may be achieved with the collateral use of Volume 2 - Access Vocabulary

Feature-Based Probabilistic Data Association for Video-Based Multi-Object Tracking

This work proposes a feature-based probabilistic data association and tracking approach (FBPDATA) for multi-object tracking. FBPDATA is based on re-identification and tracking of individual video image points (feature points) and aims at solving the problems of partial, split (fragmented), bloated or missed detections, which are due to sensory or algorithmic restrictions, limited field of view of the sensors, as well as occlusion situations

NASA Thesaurus. Volume 2: Access vocabulary

The NASA Thesaurus -- Volume 2, Access Vocabulary -- contains an alphabetical listing of all Thesaurus terms (postable and nonpostable) and permutations of all multiword and pseudo-multiword terms. Also included are Other Words (non-Thesaurus terms) consisting of abbreviations, chemical symbols, etc. The permutations and Other Words provide 'access' to the appropriate postable entries in the Thesaurus