165 research outputs found

    A Distributed Version of the Hungarian Method for Multi-Robot Assignment

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    In this paper, we propose a distributed version of the Hungarian Method to solve the well known assignment problem. In the context of multi-robot applications, all robots cooperatively compute a common assignment that optimizes a given global criterion (e.g. the total distance traveled) within a finite set of local computations and communications over a peer-to-peer network. As a motivating application, we consider a class of multi-robot routing problems with "spatio-temporal" constraints, i.e. spatial targets that require servicing at particular time instants. As a means of demonstrating the theory developed in this paper, the robots cooperatively find online, suboptimal routes by applying an iterative version of the proposed algorithm, in a distributed and dynamic setting. As a concrete experimental test-bed, we provide an interactive "multi-robot orchestral" framework in which a team of robots cooperatively plays a piece of music on a so-called orchestral floor

    A conceptual treadmill: the need for ‘middle ground’ in clinical decision making theory in nursing

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    This paper explores the two predominant theoretical approaches to the process of nurse decision making prevalent within the nursing research literature: systematic-positivistic approaches as exemplifed by information processing theory, and the intuitive-humanistic approach of Patricia Benner. The two approaches' strengths and weaknesses are explored and as a result a third theoretical stance is proffered: the idea of a cognitive continuum. According to this approach the systematic and intuitive theoretical camps occupy polar positions at either end of a continuum as opposed to separate theoretical planes. The methodological and professional benefits of adopting such a stance are also briefly outlined

    Epigenetic effects of learning and memory in the I-Ppo-I mouse

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    The epigenetics of the aging brain is a growing field of study that holds great promise for the discovery of mechanisms and potential treatments for neurodegenerative diseases. In this current study, a novel, accelerated aging murine model, the I-PpoI/Cre, or ICE (Inducible Changes in the Epigenome) mouse, is studied to test its potential for demonstrating the theory of the rearrangement of chromatin (RCM) as the main cause of aging, and in particular, the mechanism through which the brain ages. Immunohistochemistry and behavioral assays are utilized to determine whether there are morphological changes, inflammatory response, and changes in learning and memory. Results showed a significant increase in microglia and astrocytes, markers of inflammation, in I-PpoI/Cre mice compared to their Cre controls. Long term memory performance was also significantly decreased in the I-PpoI/Cre mice, demonstrated through contextual fear conditioning (CFC) testing, and Morris Water Maze (MWM) testing. Results from this study are in support of the I-PpoI/Cre mouse as a model of accelerated aging of the brain, with deficits in learning and memory. Further studies are needed to further characterize this murine model of accelerated aging

    Distilled Sensing: Adaptive Sampling for Sparse Detection and Estimation

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    Adaptive sampling results in dramatic improvements in the recovery of sparse signals in white Gaussian noise. A sequential adaptive sampling-and-refinement procedure called Distilled Sensing (DS) is proposed and analyzed. DS is a form of multi-stage experimental design and testing. Because of the adaptive nature of the data collection, DS can detect and localize far weaker signals than possible from non-adaptive measurements. In particular, reliable detection and localization (support estimation) using non-adaptive samples is possible only if the signal amplitudes grow logarithmically with the problem dimension. Here it is shown that using adaptive sampling, reliable detection is possible provided the amplitude exceeds a constant, and localization is possible when the amplitude exceeds any arbitrarily slowly growing function of the dimension.Comment: 23 pages, 2 figures. Revision includes minor clarifications, along with more illustrative experimental results (cf. Figure 2

    Black Lives Matter Otherwise All Lives Do Not Matter

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    Long before three African American women registered the twitter handle, #BlackLivesMatter, and started sending out tweets that helped to mobilize the spontaneous outrage against the impunity that followed the killings of unarmed black people by police officers and by vigilante in the US, there was always a rich history of resistance against criminal justice oppression by people of African descent and their allies. Apologists for white supremacist violence tend to reject the truism that Black Lives Matter by countering with All Lives Matter as if the later could hold if the former is rejected. In other words, since All Lives Matter, it follows that Black Lives Matter too and if by any logic Black Lives do not Matter, then All Lives do not Matter. The reason why it is even necessary to state what should be obvious, that Black Lives Matter, is exactly because there are still people who believe that certain lives belong to the homo sacer and are disposable to be taken without any consequences. This editorial complicates this issue by demonstrating the theory of Martin Luther King Jr. that injustice anywhere is a threat to justice everywhere. By treating Black Lives as if they do not Matter, the lives of human beings everywhere are threatened and so all should rally in support of Black Lives in the interest of humanity. It is not an act of charity when others support Black Lives Matter

    Theories of Discrimination & Gay Marriage

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    Drawing as language: the systemic-functional semiotic argument.

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    This article argues that drawing is a medium of visual communication, using any tool leaving a trace upon a surface, capable of referring to objects and events in the past, present and future, real and imaginary, functioning to modulate the viewer’s attitude towards the subject-matter through the systematic selection and combination of visual elements according to cultural conventions which are subject to challenge, change and misunderstandings. In other words, I argue that drawing operates as language, defined in terms of systemic-functional semiotic theory. The theoretical basis is explained and discussed, with examples of the author’s drawings demonstrating the theory as driver of creativity, facilitating the negotiation of meaning
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