9,551 research outputs found

    Factors Contributing to the Catastrophe in Mexico City During the Earthquake of September 19, 1985

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    The extensive damage to high‐rise buildings in Mexico City during the September 19, 1985 earthquake is primarily due to the intensity of the ground shaking exceeding what was previously considered credible for the city by Mexican engineers. There were two major factors contributing to the catastrophe, resonance in the sediments of an ancient lake that once existed in the Valley of Mexico, and the long duration of shaking compared with other coastal earthquakes in the last 50 years. Both of these factors would be operative again if the Guerrero seismic gap ruptured in a single earthquake

    Model Reduction of Multi-Dimensional and Uncertain Systems

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    We present model reduction methods with guaranteed error bounds for systems represented by a Linear Fractional Transformation (LFT) on a repeated scalar uncertainty structure. These reduction methods can be interpreted either as doing state order reduction for multi-dimensionalsystems, or as uncertainty simplification in the case of uncertain systems, and are based on finding solutions to a pair of Linear Matrix Inequalities (LMIs). A related necessary and sufficient condition for the exact reducibility of stable uncertain systems is also presented

    Developing a Mammalian Behaviour Ontology

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    The use of the Entity + Quality (EQ) model in phenotypic descriptions is dependent on the use of specialised domain ontologies to define the entity under observation. A domain currently lacking a specialised ontology is mammalian behaviour, and so the Mammalian Behaviour Ontology is being constructed to address this. Top-level class distinctions are made between behavioural activities and behavioural functions of individuals, and those between two or more individuals. The ontology is manually developed and encourages contributions from domain experts

    Sol

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    Sol. Spirituality for the digital age. A move towards a more cosmic future. A hopeful call to arms for a more inclusive, liberated culture where the impermanence of life can wash over us in a wave of ambient sonic splendor. Using solar energy to create shifting ambient soundscape Sol is an immersive, interactive civic space for all lifeforms of all persuasions. A reintrepretation of the Shinto shrine for the digital age. An alliance between codified physical computing, emerging interactive technology and the ancient spiritual traditions of the East. Non denominational, non religious wholly universal. Where all beings can remember their cosmic core, their common primordial source, where everything is united through the vibrational properties of sound and light. This is the common link. Vibrational force. Sun to light, light to sound and back again. The great circle of vibrational energy. A place where your presence creates the experience. A reminder that we create our own reality. Awareness of this is the great liberator. Sol the tool

    Object linking in repositories

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    This topic is covered in three sections. The first section explores some of the architectural ramifications of extending the Eichmann/Atkins lattice-based classification scheme to encompass the assets of the full life cycle of software development. A model is considered that provides explicit links between objects in addition to the edges connecting classification vertices in the standard lattice. The second section gives a description of the efforts to implement the repository architecture using a commercially available object-oriented database management system. Some of the features of this implementation are described, and some of the next steps to be taken to produce a working prototype of the repository are pointed out. In the final section, it is argued that design and instantiation of reusable components have competing criteria (design-for-reuse strives for generality, design-with-reuse strives for specificity) and that providing mechanisms for each can be complementary rather than antagonistic. In particular, it is demonstrated how program slicing techniques can be applied to customization of reusable components

    Ionized Gas Kinematics at High Resolution IV: Star Formation and a Rotating Core in the Medusa (NGC 4194)

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    NGC 4194 is a post-merger starburst known as The Medusa for its striking tidal features. We present here a detailed study of the structure and kinematics of ionized gas in the central 0.65 kpc of the Medusa. The data include radio continuum maps with resolution up to 0.18\arcsec (35 pc) and a 12.8μ12.8\mum [NeII] data cube with spectral resolution 4\sim4\kms: the first {\it high resolution, extinction-free} observations of this remarkable object. The ionized gas has the kinematic signature of a core in solid-body rotation. The starburst has formed a complex of bright compact \HII~regions, probably excited by deeply embedded super star clusters, but none of these sources is a convincing candidate for a galactic nucleus. The nuclei of the merger partners that created the Medusa have not yet been identified.Comment: to appear in Ap

    Ionized Gas Kinematics At High Resolution. II. Discovery Of A Double Infrared Cluster In II Zw 40

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    The nearby dwarf galaxy II Zw 40 hosts an intense starburst. At the center of the starburst is a bright compact radio and infrared source, thought to be a giant dense H II region containing approximate to 14,000 O stars. Radio continuum images suggest that the compact source is actually a collection of several smaller emission regions. We accordingly use the kinematics of the ionized gas to probe the structure of the radio-infrared emission region. With TEXES on the NASA-IRTF we measured the 10.5 mu m [S IV] emission line with effective spectral resolutions, including thermal broadening, of similar to 25 and similar to 3 km s(-1) and spatial resolution similar to 1 ''. The line profile shows two distinct, spatially coextensive, emission features. The stronger feature is at galactic velocity and has FWHM 47 km s(-1). The second feature is similar to 44 km s(-1) redward of the first and has FWHM 32 km s(-1). We argue that these are two giant embedded clusters, and estimate their masses to be approximate to 3 x 10(5) M-circle dot and approximate to 1.5 x 10(5) M-circle dot. The velocity shift is unexpectedly large for such a small spatial offset. We suggest that it may arise in a previously undetected kinematic feature remaining from the violent merger that formed the galaxy.University of Hawaii NNX-08AE38ANSF AST-0607312NASAAstronom
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