1,877 research outputs found

    Parenting through the Ages: An Investigation into Familial Grief in The Iliad and Modern Times

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    Undergraduate Textual or Investigativ

    Poetic Economics: Phillis Wheatley and the Production of the Black Artist in the Early Atlantic World

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    This essay reads Wheatley as a key participant in the shifting economic and emotional relationships between artists, audiences, and texts that we now associate with romanticism. To recover facets of the role that the black artist played in the romantic movement(s), I examine three portraits of Wheatley-the poetic spectacle managed by her promoters, the actual portrait that appeared as the frontispiece for her Poems on Various Subjects, and the portrait that Wheatley herself created through her poetry. These portraits chart the tensions that circulated around the figure of the black African artist 111 the eighteenth-century Atlantic world, tensions between genius and barbarity, originality and imitation, exteriority and interiority, and artistic expression and commodification. These binaries have often characterized the terrain of Wheatley studies, marking opposing positions and points of contention. I argue for a different way of reading, one that sees the figure of Phillis Wheatley as produced through the interplay of all of these forces within the context of the early black Atlantic. Wheatley and her work exposed both the emphasis on authentic self-expression through art and the ways in which the mental life of the artist became available to the reader as a consumer product. She created a different vision of the black artist than that which commonly circulated in the eighteenth-century Atlantic world, one that fused Christian discourse with romantic elements of imagination, Nature, and the poetic sublime, yet remained distant from and somewhat inaccessible to white readers. Keywords: Wheatley, black Atlantic, poetry, romanti

    Robust adaptive kinematic control of redundant robots

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    The paper presents a general method for the resolution of redundancy that combines the Jacobian pseudoinverse and augmentation approaches. A direct adaptive control scheme is developed to generate joint angle trajectories for achieving desired end-effector motion as well as additional user defined tasks. The scheme ensures arbitrarily small errors between the desired and the actual motion of the manipulator. Explicit bounds on the errors are established that are directly related to the mismatch between actual and estimated pseudoinverse Jacobian matrix, motion velocity and the controller gain. It is shown that the scheme is tolerant of the mismatch and consequently only infrequent pseudoinverse computations are needed during a typical robot motion. As a result, the scheme is computationally fast, and can be implemented for real-time control of redundant robots. A method is incorporated to cope with the robot singularities allowing the manipulator to get very close or even pass through a singularity while maintaining a good tracking performance and acceptable joint velocities. Computer simulations and experimental results are provided in support of the theoretical developments

    Comments on Peter Master's “The Etiquette of Observing’ A Reader Reacts …: The Dynamics of Classroom Observation: Evening the Odds Through Information

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90177/1/3586701.pd

    Must Organic certification fundamentally change for an Organic World?

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    Organic guarantee systems have evolved drastically in the past, accompanying changes in the uptake of Organic agriculture. From an originally fully stakeholder-driven and participatory process in the '70s and '80s, organic certification has become increasingly formalized and government-controlled. organic certification is a must-have for organic market access in more and more countries in the world, but is often not seen by producers to add much value beyond that. It claims to bring transparency and trust to the consumers, but it also delegates the judgment of agricultural practices to more or less anonymous entities. Certification is not designed to prevent fraud but it is expected to control and detect it. Organic certification and regulations are supposed to be tools to develop organic markets but at the same time create barriers to organic trade. Requirements for organic certification are continuously increasing and becoming more complex, yet organic certification is not seen as more reliable than it was a decade ago. Finally, standard setters are torn between the society's expectation that organic certification cover a wider range of sustainability topics, and the fear that more onerous requirements will inhibit conversion to Organic. All these paradoxes are becoming increasingly apparent as the organic movement reflects on how to scale up Organic Agriculture from a niche to the mainstream way of farming

    Jeeg: Temporal Constraints for the Synchronization of Concurrent Objects

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    We introduce Jeeg, a dialect of Java based on a declarative replacement of the synchronization mechanisms of Java that results in a complete decoupling of the 'business' and the 'synchronization' code of classes. Synchronization constraints in Jeeg are expressed in a linear temporal logic which allows to effectively limit the occurrence of the inheritance anomaly that commonly affects concurrent object oriented languages. Jeeg is inspired by the current trend in aspect oriented languages. In a Jeeg program the sequential and concurrent aspects of object behaviors are decoupled: specified separately by the programmer these are then weaved together by the Jeeg compiler

    Stash in a Flash

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    Encryption is a useful tool to protect data confidentiality. Yet it is still challenging to hide the very presence of encrypted, secret data from a powerful adversary. This paper presents a new technique to hide data in flash by manipulating the voltage level of pseudo-randomlyselected flash cells to encode two bits (rather than one) in the cell. In this model, we have one “public” bit interpreted using an SLC-style encoding, and extract a private bit using an MLC-style encoding. The locations of cells that encode hidden data is based on a secret key known only to the hiding user. Intuitively, this technique requires that the voltage level in a cell encoding data must be (1) not statistically distinguishable from a cell only storing public data, and (2) the user must be able to reliably read the hidden data from this cell. Our key insight is that there is a wide enough variation in the range of voltage levels in a typical flash device to obscure the presence of fine-grained changes to a small fraction of the cells, and that the variation is wide enough to support reliably re-reading hidden data. We demonstrate that our hidden data and underlying voltage manipulations go undetected by support vector machine based supervised learning which performs similarly to a random guess. The error rates of our scheme are low enough that the data is recoverable months after being stored. Compared to prior work, our technique provides 24x and 50x higher encoding and decoding throughput and doubles the capacity, while being 37x more power efficient

    Iterative focused screening with biological fingerprints identifies selective Asc-1 inhibitors distinct from traditional high throughput screening

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    N-methyl-d-aspartate receptors (NMDARs) mediate glutamatergic signaling that is critical to cognitive processes in the central nervous system, and NMDAR hypofunction is thought to contribute to cognitive impairment observed in both schizophrenia and Alzheimer’s disease. One approach to enhance the function of NMDAR is to increase the concentration of an NMDAR coagonist, such as glycine or d-serine, in the synaptic cleft. Inhibition of alanine–serine–cysteine transporter-1 (Asc-1), the primary transporter of d-serine, is attractive because the transporter is localized to neurons in brain regions critical to cognitive function, including the hippocampus and cortical layers III and IV, and is colocalized with d-serine and NMDARs. To identify novel Asc-1 inhibitors, two different screening approaches were performed with whole-cell amino acid uptake in heterologous cells stably expressing human Asc-1: (1) a high-throughput screen (HTS) of 3 M compounds measuring 35S l-cysteine uptake into cells attached to scintillation proximity assay beads in a 1536 well format and (2) an iterative focused screen (IFS) of a 45 000 compound diversity set using a 3H d-serine uptake assay with a liquid scintillation plate reader in a 384 well format. Critically important for both screening approaches was the implementation of counter screens to remove nonspecific inhibitors of radioactive amino acid uptake. Furthermore, a 15 000 compound expansion step incorporating both on- and off-target data into chemical and biological fingerprint-based models for selection of additional hits enabled the identification of novel Asc-1-selective chemical matter from the IFS that was not identified in the full-collection HTS

    Parameterized Model-Checking for Timed-Systems with Conjunctive Guards (Extended Version)

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    In this work we extend the Emerson and Kahlon's cutoff theorems for process skeletons with conjunctive guards to Parameterized Networks of Timed Automata, i.e. systems obtained by an \emph{apriori} unknown number of Timed Automata instantiated from a finite set U1,,UnU_1, \dots, U_n of Timed Automata templates. In this way we aim at giving a tool to universally verify software systems where an unknown number of software components (i.e. processes) interact with continuous time temporal constraints. It is often the case, indeed, that distributed algorithms show an heterogeneous nature, combining dynamic aspects with real-time aspects. In the paper we will also show how to model check a protocol that uses special variables storing identifiers of the participating processes (i.e. PIDs) in Timed Automata with conjunctive guards. This is non-trivial, since solutions to the parameterized verification problem often relies on the processes to be symmetric, i.e. indistinguishable. On the other side, many popular distributed algorithms make use of PIDs and thus cannot directly apply those solutions
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