236 research outputs found

    Collaborative Ontology Development — Distributed Architecture and Visualization

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    In this paper we present the architecture of the browser-based community-driven ontology engineering platform Ontoverse. We will present the architectural needs and designs for an extensible collaborative ontology platform as well as the current implementation based on tuplespaces. In this context we briefly introduce the SQLSpaces and the Semantic Web Application Toolkit (SWAT). To provide interactive collaborative means for editing, merging, and discussing about ontologies adequate visualization techniques are needed to support the ontology designers and ontology users. Therefore we introduce a visualization method called SmartTree that implements focus and context techniques

    Snowy Plover Activity in the Central Platte River Valley in May 2019

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    During five of eight site visits between 14 and 27 May 2019 we detected up to four Snowy Plovers (Charadrius nivosus nivosus) in the Central Platte River Valley (CPRV) near Mormon Island, Hall County, Nebraska, and recorded their behavior using an instantaneous scan sampling approach. We recorded loafing (47%), foraging (43%), mating (4%), flying (4%), and external threat (1%) related behavior. Most notably, we documented a copulation event on 23 May. During the 10-day span from 14 to 23 May when Snowy Plovers were detected, river stage and discharge were near median levels, but from 23 to 27 May river discharge more than doubled and gage height increased by over 20%. This resulted in sandbar habitat becoming submerged and the Snowy Plovers vacating the site. This observation illustrates how wide variation in late spring flows can preclude potential breeding by ground nesting waterbirds in the CPRV given the current limited availability of unvegetated sandbars significantly exceeding flood stage. This represents a notable late-spring stay length in the CPRV with behavior suggestive of the potential for local breeding

    Correlations between hidden units in multilayer neural networks and replica symmetry breaking

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    We consider feed-forward neural networks with one hidden layer, tree architecture and a fixed hidden-to-output Boolean function. Focusing on the saturation limit of the storage problem the influence of replica symmetry breaking on the distribution of local fields at the hidden units is investigated. These field distributions determine the probability for finding a specific activation pattern of the hidden units as well as the corresponding correlation coefficients and therefore quantify the division of labor among the hidden units. We find that although modifying the storage capacity and the distribution of local fields markedly replica symmetry breaking has only a minor effect on the correlation coefficients. Detailed numerical results are provided for the PARITY, COMMITTEE and AND machines with K=3 hidden units and nonoverlapping receptive fields.Comment: 9 pages, 3 figures, RevTex, accepted for publication in Phys. Rev.

    Statistical Mechanical Development of a Sparse Bayesian Classifier

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    The demand for extracting rules from high dimensional real world data is increasing in various fields. However, the possible redundancy of such data sometimes makes it difficult to obtain a good generalization ability for novel samples. To resolve this problem, we provide a scheme that reduces the effective dimensions of data by pruning redundant components for bicategorical classification based on the Bayesian framework. First, the potential of the proposed method is confirmed in ideal situations using the replica method. Unfortunately, performing the scheme exactly is computationally difficult. So, we next develop a tractable approximation algorithm, which turns out to offer nearly optimal performance in ideal cases when the system size is large. Finally, the efficacy of the developed classifier is experimentally examined for a real world problem of colon cancer classification, which shows that the developed method can be practically useful.Comment: 13 pages, 6 figure

    Storage capacity of correlated perceptrons

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    We consider an ensemble of KK single-layer perceptrons exposed to random inputs and investigate the conditions under which the couplings of these perceptrons can be chosen such that prescribed correlations between the outputs occur. A general formalism is introduced using a multi-perceptron costfunction that allows to determine the maximal number of random inputs as a function of the desired values of the correlations. Replica-symmetric results for K=2K=2 and K=3K=3 are compared with properties of two-layer networks of tree-structure and fixed Boolean function between hidden units and output. The results show which correlations in the hidden layer of multi-layer neural networks are crucial for the value of the storage capacity.Comment: 16 pages, Latex2

    Landscape-Level Long-Term Biological Research and Monitoring Plan for the Crane Trust

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    Our obligation is to make sure we are effectively utilizing science to meet the objectives of the Platte River Whooping Crane Maintenance Trust (1981) laid out in its charter “to rehabilitate and preserve a portion of the habitat for Whooping Cranes and other migratory birds in the Big Bend reach of the Platte River between Overton and Chapman (i.e., Central Platte River Valley), Nebraska”. The original declaration is aimed at maintaining “the physical, hydrological, and biological integrity of the Big Bend area as a life-support system for the Whooping Crane and other migratory species that utilize it.” It was clear from the institution’s founding that to accomplish this goal it was necessary to study the effectiveness of land conservation and management actions in providing habitat for Whooping Cranes and other migratory bird species. Quality habitat necessarily comprises all the components that Whooping Cranes and other migratory bird life require to complete their migrations –food and shelter– including nutrient rich diet items such as invertebrates, vascular plants, herpetofauna, fish, and small mammals as well as suitable roosting and foraging locations including wide braided rivers and undisturbed wet meadows (Allen 1952; Steenhof et al. 1988; Geluso 2013; Caven et al. 2019, 2021). Article “A” of the Crane Trust’s (1981) declaration is “to establish a written habitat monitoring plan which can be used to describe change in…[habitat] within the Big Bend of the Platte River…utilized by Sandhill Cranes and Whooping Cranes….” Following initial inventories including avian (Hay and Lingle 1982), vegetation (Kolstad 1981; Nagel 1981), small mammals (Springer 1981), herpetofauna (Jones et al. 1981), insects (Ratcliffe 1981), and fish (Cochar and Jenson 1981), a variety of excellent research has continued at the Crane Trust (https://cranetrust.org/conservation-research/publications/). However, despite the clarity of the Trust’s original declaration, long-term habitat monitoring has not progressed unabated throughout the history of the Crane Trust.https://digitalcommons.unl.edu/zeabook/1130/thumbnail.jp
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