Home  About us  Contact
 

Open Issues (open + issues)

Distribution by Scientific Domains
Medical Sciences33%
Information Science and Computing22%
Engineering22%

Selected Abstracts

Middleware benchmarking: approaches, results, experiences,

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 15 2005
Paul Brebner
Abstract The report summarizes the results of the Workshop on Middleware Benchmarking held during OOPSLA 2003. The goal of the workshop was to help advance the current practice of gathering performance characteristics of middleware implementations through benchmarking. The participants of the workshop have focused on identifying requirements of and obstacles to middleware benchmarking and forming a position on the related issues. Selected requirements and obstacles are presented, together with guidelines to adhere to when benchmarking, open issues of current practice, and perspectives on further research. Copyright © 2005 John Wiley & Sons, Ltd. [source]

From phagocyte diversity and activation to probiotics: Back to Metchnikoff

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 12 2008
Alberto Mantovani
Abstract In this issue of the European Journal of Immunology, Siamon Gordon gives a detailed account of Metchnikoff's life and his achievements (Eur. J. Immunol. 2008. 38: 3257,3264). Looking back at the roots of innate immunity stimulates reflections on open issues in the field. Here, I give a personal view of some of these issues, including myeloid-derived suppressor cells, macrophage polarization and adaptive responses of mononuclear phagocytes. [source]

Optimized damage detection of steel plates from noisy impact test

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 7 2006
G. Rus
Abstract Model-based non-destructive evaluation proceeds measuring the response after an excitation on an accessible area of the structure. The basis for processing this information has been established in recent years as an iterative scheme that minimizes the discrepancy between this experimental measurement and sequence of measurement trials predicted by a numerical model. The unknown damage that minimizes this discrepancy by means of a cost functional is to be found. The damage location and size is quantified and sought by means of a well-conditioned parametrization. The design of the magnitude to measure, its filtering for reducing noise effects and calibration, as well as the design of the cost functional and parametrization, determines the robustness of the search to combat noise and other uncertainty factors. These are key open issues to improve the sensitivity and identifiability during the information processing. Among them, a filter for the cost functional is proposed in this study for maximal sensitivity to the damage detection of steel plate under the impact loading. This filter is designed by means of a wavelet decomposition together with a selection of the measuring points, and the optimization criterion is built on an estimate of the probability of detection, using genetic algorithms. Numerical examples show that the use of the optimal filter allows to find damage of a magnitude several times smaller. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Maastricht's Fiscal Rules at Ten: An Assessment

JCMS: JOURNAL OF COMMON MARKET STUDIES, Issue 5 2002
Marco Buti
The Maastricht Treaty is ten years old. Its fiscal rules played a key role in kickstarting and sustaining the budgetary retrenchment efforts in European Union countries in the run,up to economic and monetary union (EMU). The experience of the Maastricht,induced fiscal consolidation shows that the political economy dimension of the rules is key to their success. It remains to be seen whether the stability and growth pact , which aims to lock EMU members into a permanent fiscal discipline commitment while allowing for flexibility to cushion cyclical fluctuations , will work. In order to succeed in this undertaking, EU governments and institutions have to tackle a number of open issues in the implementation of the pact while recreating the political drive which made Maastricht a success. [source]

Cooperative use of unmanned sea surface and micro aerial vehicles at Hurricane Wilma

JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 3 2008
Robin R. Murphy
On Oct. 24, 2005, Hurricane Wilma, a category 5 storm, made landfall at Cape Romano, Florida. Three days later, the Center for Robot-Assisted Search and Rescue at the University of South Florida deployed an iSENYS helicopter and a prototype unmanned water surface vehicle, AEOS-1, to survey damage in parts of Marco Island, 14 km from landfall. The effort was the first known use of unmanned sea surface vehicles (USVs) for emergency response and established their suitability for the recovery phase of disaster management by detecting damage to seawalls and piers, locating submerged debris (moorings and handrails), and determining safe lanes for sea navigation. It provides a preliminary domain theory of postdisaster port and littoral inspection with unmanned vehicles for use by the human,robot interaction community. It was also the first known demonstration of the strongly heterogeneous USV,micro aerial vehicle (MAV) team for any domain. The effort identified cooperative UAV,USV strategies and open issues for autonomous operations near structures. The effort showed that the MAV provided a much-needed external view for situation awareness and provided spotting for areas to be inspected. Concepts of operations for USV damage inspection and USV,MAV cooperation emerged, including a formula for computing the human,robot ratio: Nh = (2 × Nv) + 1, where Nh is the number of humans and Nv is the number of vehicles. The outstanding research issues span three areas: challenges for USVs operating near littoral structures, general issues for USV,MAV cooperation, and new applications. It is expected that the lessons learned will be transferrable to defense and homeland safety and security applications, such as port security, and other phases of emergency response, including rescue. © 2008 Wiley Periodicals, Inc. [source]

A survey in indexing and searching XML documents

JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 6 2002
Robert W.P. Luk
XML holds the promise to yield (1) a more precise search by providing additional information in the elements, (2) a better integrated search of documents from heterogeneous sources, (3) a powerful search paradigm using structural as well as content specifications, and (4) data and information exchange to share resources and to support cooperative search. We survey several indexing techniques for XML documents, grouping them into flat-file, semistructured, and structured indexing paradigms. Searching techniques and supporting techniques for searching are reviewed, including full text search and multistage search. Because searching XML documents can be very flexible, various search result presentations are discussed, as well as database and information retrieval system integration and XML query languages. We also survey various retrieval models, examining how they would be used or extended for retrieving XML documents. To conclude the article, we discuss various open issues that XML poses with respect to information retrieval and database research. [source]

Pathophysiological concepts of restless legs syndrome

MOVEMENT DISORDERS, Issue 10 2007
Walter Paulus MD
Abstract Pathophysiological concepts of restless legs syndrome (RLS) are based mainly on neuroimaging and on neurophysiological data. Furthermore treatment effects contribute essentially to the present understanding of the disease, unless the genetic progress expected in the near future will clarify substantially open issues. The concept agreed on assumes a dysfunction of the dopaminergic system, possibly on the level of striatal and/or spinal dopamine receptors, and the A11 neuron group localized in the hypothalamus as an integrated part of the system. These neurons modulate spinal excitability, alterations of which in turn affect sensory processing predominantly of leg afferents in brain stem structures. Neurophysiologically excitability alterations can be measured by a variety of methods such as determination of pain thresholds, H-reflex testing, and quantitative sensory testing. © 2007 Movement Disorder Society [source]

Motoneurons: A preferred firing range across vertebrate species?

MUSCLE AND NERVE, Issue 5 2002
T. George Hornby PhD
Abstract The term "preferred firing range" describes a pattern of human motor unit (MU) unitary discharge during a voluntary contraction in which the profile of the spike-frequency of the MU's compound action potential is dissociated from the profile of the presumed depolarizing pressure exerted on the unit's spinal motoneuron (MN). Such a dissociation has recently been attributed by inference to the presence of a plateau potential (PP) in the active MN. This inference is supported by the qualitative similarities between the firing pattern of human MUs during selected types of relatively brief muscle contraction and that of intracellularly stimulated, PP-generating cat MNs in a decerebrate preparation, and turtle MNs in an in vitro slice of spinal cord. There are also similarities between the stimulus-response behavior of intracellularly stimulated turtle MNs and human MUs during the elaboration of a slowly rising voluntary contraction. This review emphasizes that there are a variety of open issues concerning the PP. Nonetheless, a rapidly growing body of comparative vertebrate evidence supports the idea that the PP and other forms of non-linear MN behavior play a major role in the regulation of muscle force, from the lamprey to the human. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000,000, 2002 [source]

Unconventional superconductivity and magnetism in Sr2RuO4 and related materials

ANNALEN DER PHYSIK, Issue 3 2004
I. Eremin
Abstract We review the normal and superconducting state properties of the unconventional triplet superconductor Sr2RuO4 with an emphasis on the analysis of the magnetic susceptibility and the role played by strong electronic correlations. In particular, we show that the magnetic activity arises from the itinerant electrons in the Ru d -orbitals and a strong magnetic anisotropy occurs (,+- < ,zz) due to spin-orbit coupling. The latter results mainly from different values of the g -factor for the transverse and longitudinal components of the spin susceptibility (i.e. the matrix elements differ). Most importantly, this anisotropy and the presence of incommensurate antiferromagnetic and ferromagnetic fluctuations have strong consequences for the symmetry of the superconducting order parameter. In particular, reviewing spin fluctuation-induced Cooper-pairing scenario in application to Sr2RuO4 we show how p -wave Cooper-pairing with line nodes between neighboring RuO2 -planes may occur. We also discuss the open issues in Sr2RuO4 like the influence of magnetic and non-magnetic impurities on the superconducting and normal state of Sr2RuO4. It is clear that the physics of triplet superconductivity in Sr2RuO4 is still far from being understood completely and remains to be analyzed more in more detail. It is of interest to apply the theory also to superconductivity in heavy-fermion systems exhibiting spin fluctuations. [source]