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Systems Science (system + science)

Distribution by Scientific Domains
Mathematics and Statistics40%

Selected Abstracts

The fractional congestion bound for efficient edge disjoint routing

NETWORKS: AN INTERNATIONAL JOURNAL, Issue 3 2008
Alok Baveja
Abstract This article investigates the following problem: Given the fractional relaxation of the edge disjoint routing problem, how small a fractional congestion is sufficient to guarantee efficient edge disjoint routing? That is, what is the largest possible value v such that a fractional flow with congestion at most v, can be efficiently converted into an edge disjoint routing? Leighton, Lu, Rao, and Srinivasan (SIAM J Comput 2001) have established that fractional congestion of at most the order of O(1/(d log k)) is sufficient, where d is the maximum path length in the fractional relaxation, and k is the number of pairs to be routed. It is also known that ,(1/d) is the correct bound, if we are only interested in an existence result (Leighton, Rao, and Srinivasan, Hawaii International Conference on System Sciences, 1998). Motivated by the fact that d is small for many types of routing problems, specifically, polylogarithmic for expander graphs, this article improves upon the former result by showing O(1/(d log d)) fractional congestion to suffice. © 2007 Wiley Periodicals, Inc. NETWORKS, 2008 [source]

Science, systems and geomorphologies: why LESS may be more

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 9 2008
Keith Richards
Abstract This paper has been stimulated by a debate triggered by the then British Geomorphological Research Group (now the British Society for Geomorphology) about the connections between geomorphology and Earth system science (ESS). Its purpose is to expand on some arguments we have already made about these connections, amongst other things drawing attention to neglected historical antecedents, and to the questionable status of the science implied by ESS. A premise of this further paper is that such a debate cannot be assumed to mirror conventional assessments of the content of a science, since it is about scientific institutional structures, names, boundaries and relationships. This implies that the terms of reference go well beyond critical scientific appraisal, extending to matters of evaluating a social organization, and to politics, policies, purposes and practices. We therefore begin by considering the sociology of science, scientific knowledge and technology, before moving to a consideration of the historical relationship amongst geomorphology, geology and physical geography; and to some perspectives this might offer for the current debate. Epistemological issues, arising both from the use of systems theory over multiple spatial and temporal scales, and from the demands of contemporary environmental science, are then introduced, and these lead to a conclusion that geomorphology might more appropriately be assessed against (or seen as part of) a more locally orientated ESS, which we term LESS. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Quality and Safety in a Complex World: Why Systems Science Matters to Otolaryngologists,

THE LARYNGOSCOPE, Issue 10 2004
David W. Roberson MD
Almost all modern medical care is delivered in the setting of many overlapping systems. Each system may consist of multiple providers and in most cases electronic and mechanical components. Even "simple" outpatient care is delivered by teams of providers, administrators, and devices. Critically ill inpatients are cared for in extraordinarily complex systems with hundreds of human and non-human elements. The science of complex systems has exploded in recent decades, and there is a large body of knowledge about how such systems function effectively or ineffectively. Many principles of systems science are simple to understand and apply, but few Otolaryngologists are well educated about them. A basic knowledge of systems science will greatly improve the Otolaryngologist's ability to function in complex health care systems and to provide the best care for his or her patients. [source]

Analysis and design of networked control systems using the additive noise model methodology,

ASIAN JOURNAL OF CONTROL, Issue 4 2010
Graham C. Goodwin
Abstract Networked Control has emerged in recent years as a new and exciting area in systems science. The topic has many potential applications in diverse areas ranging from control of microrobots to biological and economic systems. The supporting theory is very rich and combines aspects of control, signal processing, telecommunications, and information theory. In this paper, we give a partial overview of recent developments in Networked Control with an emphasis on the additive noise model methodology. We also point to several open problems in this emerging area. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source]

Classification of emergence and its relation to self-organization

COMPLEXITY, Issue 5 2008
Julianne.
Emergence is a difficult concept to describe clearly. It has been characterized in the literature in a number of ways, none of which are easy to understand or describe clearly how other concepts in complex systems science are related to emergence. We provide a simple, clear description, and classification of emergence in terms of self-organization. This provides a framework for understanding how concepts such as thermodynamic equilibrium, nonlinearity, and computability are related to emergence. © 2008 Wiley Periodicals, Inc. Complexity, 2008. [source]