Complexity

Distribution by Scientific Domains

Kinds of Complexity

  • additional complexity
  • architectural complexity
  • biological complexity
  • cognitive complexity
  • computation complexity
  • computational complexity
  • cultural complexity
  • decoding complexity
  • different complexity
  • food web complexity
  • full complexity
  • functional complexity
  • genetic complexity
  • greater complexity
  • growing complexity
  • habitat complexity
  • high complexity
  • implementation complexity
  • increased complexity
  • increasing complexity
  • inherent complexity
  • integrative complexity
  • job complexity
  • karyotypic complexity
  • low complexity
  • lower complexity
  • model complexity
  • molecular complexity
  • morphological complexity
  • reducing complexity
  • relational complexity
  • sample complexity
  • shape complexity
  • social complexity
  • space complexity
  • spatial complexity
  • structural complexity
  • system complexity
  • task complexity
  • taxonomic complexity
  • temporal complexity
  • time complexity
  • topographic complexity
  • underlying complexity
  • web complexity

  • Terms modified by Complexity

  • complexity analysis
  • complexity increase
  • complexity inherent
  • complexity level
  • complexity measure
  • complexity science
  • complexity score
  • complexity theory

  • Selected Abstracts


    FOSTERING SUSTAINABLE COMPLEXITY IN THE MICROFINANCE INDUSTRY: WHICH WAY FORWARD?

    ECONOMIC AFFAIRS, Issue 2 2005
    Emily Chamlee-Wright
    The microfinance movement has gained tremendous popularity over the past 30 years, but it is still far from meeting its full potential. The industry stands at a crossroads between increased commercialisation and increased philanthropic aid. Standard economic discourse does little to resolve the debate. F. A. Hayek's concept of the,extended order' sheds new light on how we might understand the future development of microfinance. [source]


    VISUAL BACKGROUND COMPLEXITY FACILITATES THE EVOLUTION OF CAMOUFLAGE

    EVOLUTION, Issue 6 2003
    Sami Merilaita
    Abstract., Cryptic animal coloration or camouflage is an adaptation that decreases the risk of detection. The study of the evolution of camouflage has strongly emphasized the minimization of visual information that predators receive from prey, by means of background matching. However, the evolutionary effects of information processing after its reception have been virtually ignored. I constructed a model that employs an artificial neural network and simulates the evolution of prey coloration in a visually complex and simple habitat. The model suggests: (1) the difficulty of a detection task is related to the visual complexity of the habitat; (2) it is easier to decrease the risk of detection by the means of camouflage in a visually complex habitat; (3) selection on camouflage can exploit limitations in predators information processing; and (4) there are shortcomings in using the degree of background matching as the measure of camouflage. [source]


    ADAPTATION AND THE COST OF COMPLEXITY

    EVOLUTION, Issue 1 2000
    H. Allen Orr
    Abstract., Adaptation is characterized by the movement of a population toward a many-character optimum, movement that results in an increase in fitness. Here I calculate the rate at which fitness increases during adaptation and describe the curve giving fitness versus time as a population approaches an optimum in Fisher's model of adaptation. The results identify several factors affecting the speed of adaptation. One of the most important is organismal complexity,complex organisms adapt more slowly than simple ones when using mutations of the same phenotypic size. Thus, as Fisher foresaw, organisms pay a kind of cost of complexity. However, the magnitude of this cost is considerably larger than Fisher's analysis suggested. Indeed the rate of adaptation declines at least as fast as n -1, where n is the number of independent characters or dimensions comprising an organism. The present results also suggest that one can define an effective number of dimensions characterizing an adapting species. [source]


    GEOMORPHIC AND STRATIGRAPHIC COMPLEXITY: HOLOCENE ALLUVIAL HISTORY OF UPPER WOLLOMBI BROOK, AUSTRALIA

    GEOGRAFISKA ANNALER SERIES A: PHYSICAL GEOGRAPHY, Issue 1 2008
    WAYNE D. ERSKINE
    ABSTRACT. Holocene and post-European settlement alluvial histories of three nested drainage basins were reconstructed from detailed litho- and chronostratigraphy of cut and fill terraces and flood-plains in the upper Wollombi Brook catchment. Fernances Creek (13.8 km2) valley fill consisted of intercalated thin mud sheets deposited in ephemeral swamps and thick sand sheets deposited by discontinuous channels. Dairy Arm (39.8 km2) valley fill was more complex, with inset alluvial fills in the upper basin and overlapping vertically stacked fills in the lower basin. However, correlative lithostrati-graphic units were not found on all tributaries. Furthermore, basal radiocarbon dates on the last inset fill of four tributaries did not overlap, allowing for plus or minus twice the standard deviation of the reported ages. Wollombi Brook (341 km2) valley fill was also complex, with longitudinally discontinuous units, most of which were not found in the two tributaries. Upstream late Holocene channel incision was coeval with downstream chain of ponds because sediment generated by incision was stored in the intervening valley. Historical channel incision occurred between 1838 and 1867 on Fernances Creek at a locally steeper section of valley floor during the period of peak population and frequent floods immediately after a road crossing was constructed, but coincided with a catastrophic flood on Dairy Arm (June 1949) and on Wollombi Brook (1927). Lack of correlative litho- and chronostrati-graphic units plus out-of-phase post-European incision indicate that stratigraphic complexity is a function of geomorphic complexity due to the operation of geomorphic thresholds and complex response. [source]


    CURRENT VARIABILITY SHAPES MORPHOLOGICAL COMPLEXITY IN COLONIAL STREAM DIATOMS

    JOURNAL OF PHYCOLOGY, Issue 2001
    Article first published online: 24 SEP 200
    Passy, S. I.1,2 & Freehafer, D.2 1Department of Biology, Rensselaer Polytechnic Institute, Troy, NY 12180; 2US Geological Survey, 425 Jordan Rd., Troy, NY 12180-8349 USA On August 27, 1999 diatoms were sampled, and current velocity was measured at 81 locations on a regular square sampling grid in an unshaded, cobble-bottom reach of White Creek, NY. The grid had an extent of 16 m2, interval, the distance between neighboring sampling points, of 0.5 m, and grain size, the size of the elementary sampling unit, of 0.01 m2. Six of the seven dominant benthic diatoms were colonial forms, including Diatoma vulgaris, Fragilaria capucina, F. crotonensis, Gomphoneis minuta, Melosira varians, and Synedra ulna. Their morphology and distribution were investigated from the perspective of fractal geometry and stream ecology, respectively. Fractal dimension of diatom colonies, indicative of their shape complexity, ranged from 1.06 to 1.54, demonstrating vast morphological variation from simple geometric shapes to complex outlines. The relative abundance of the six diatoms was regressed against current regime, which ranged from 0.03 to 0.66 m, s -1. All regression models were significant at P < 0.05 and explained between 55% and 94% of the variation in diatom distribution. The diatom niche breadth, i.e. the amount of environmental variability a species can tolerate, was defined from these models and showed substantial variation, from 5 to 14. The regression model of fractal dimension against niche breadth was significant and explained 76% of colonial shape variation, revealing a strong relationship between diatom colonial complexity and habitat variability. This finding suggests that environmental variability could create highly complex colonial morphologies in benthic diatoms as an evo-lutionary strategy for survival in unpredictable environments. [source]


    RELIABILITY OF SENSORY ASSESSORS: ISSUES OF COMPLEXITY

    JOURNAL OF SENSORY STUDIES, Issue 1 2009
    JANNA BITNES
    ABSTRACT The objective of this study was to investigate whether the sensory performance of assessors in a sensory panel maybe explained by complexity of evaluated product. We aimed to investigate whether we could observe a decline in sensory performance when increasing the complexity of the product. The products increased in number of constituents from mixtures of sucrose, sodium chloride, citric acid and caffeine in water, to the foods ice tea and tomato soup constituting different levels of the same substances. Candidates who succeeded evaluating one product were not always successful evaluating others. Few subjects were successful in everything. The conclusion was that there is only minor systematic decline with increasing complexity of products. The authors emphasize that definition of complexity involves more than just counting number of constituents and taste sensations, and suggest that minor differences in the task given to the assessor might explain different performances. PRACTICAL APPLICATIONS Practical use of the research presented in the present paper is in a sensory evaluation context. It is important for the users of sensory data to find out how the profiling should be organized to achieve optimum output, and in specific, the need for extensive training when dealing with a more complex product. The present study hypothesized that sensory assessors would have more difficulties evaluating a more complex product. However, the results showed that panel leaders should be more concerned with the task variables in the sensory evaluation. Even a minor shift in task variables had a stronger impact on the performance and reliability of the assessors than increasing number of constituents and/or stimuli sensations of the product. This study did not demonstrate a need for extensive training when dealing with a more complex product as hypothesized. [source]


    VERTEBRAL OSTEOLOGY AND COMPLEXITY IN LAGENORHYNCHUS ACUTUS (DELPHINIDAE) WITH COMPARISON TO OTHER DELPHINOID GENERA

    MARINE MAMMAL SCIENCE, Issue 3 2005
    Emily A. Buchholtz
    Abstract The vertebral column of the Atlantic white-sided dolphin, Lagenorhynchus acutus, reflects the radical reorganization of the cetacean column for locomotion in water. Both posterior thoracic and anterior caudal vertebrae have been "lumbarized," and discontinuities occur within the caudal series at the synclinal point and fluke base. Morphology changes subtly as body size increases. Neural process height increases more rapidly, and centrum length more variably, than other vertebral parameters. As a result, large animals have disproportionately tall neural processes, short necks, long mid-body regions, and short flukes. Vertebral columns of large animals also show greater complexity (range, irregularity, and polarization) of centrum length than do those of smaller animals. Comparisons among dolphins reveal that complexity trends with respect to differentiation of parts run counter to the trend with respect to number of parts, a relationship predicted by Williston in 1914. [source]


    III. STUDY 2: RULE COMPLEXITY AND STIMULUS CHARACTERISTICS IN EXECUTIVE FUNCTION

    MONOGRAPHS OF THE SOCIETY FOR RESEARCH IN CHILD DEVELOPMENT, Issue 3 2003
    Article first published online: 8 DEC 200
    First page of article [source]


    GEOCHEMICAL ANALYSIS AND SOCIOCULTURAL COMPLEXITY: A CASE STUDY FROM EARLY IRON AGE MEGIDDO (ISRAEL)*

    ARCHAEOMETRY, Issue 4 2005
    T. P. HARRISON
    Few archaeological sites can claim a more celebrated position than Megiddo, the Armageddon of biblical revelation. Guardian to a strategic pass on the ancient land bridge that traverses the region, it has long been known that Megiddo played a prominent role in the emergence of the Iron Age nation-states of biblical fame. Given its pivotal location, Megiddo provides an ideal opportunity to examine the experience of a community that found itself at the centre of these developments. The archaeological and textual evidence indicates a community that enjoyed extensive contact with an array of culturally distinct sociopolitical groups emerging in its hinterland. To further explore the nature and extent of this interaction, an assemblage of 86 ceramic sherds was analysed by instrumental neutron activation analysis (INAA). This paper presents the results of this analysis, together with an evaluation of potential geochemical and archaeological interconnections. Based on this comparative analysis, implications are drawn regarding Megiddo's role in the changing cultural and political landscape of this formative period in the history of the region. [source]


    Extracellular interactome of the FGF receptor,ligand system: Complexities and the relative simplicity of the worm

    DEVELOPMENTAL DYNAMICS, Issue 2 2009
    Urszula M. Polanska
    Abstract Fibroblast growth factors (FGFs) and their receptors (FGFRs) regulate a multitude of biological functions in embryonic development and in adult. A major question is how does one family of growth factors and their receptors control such a variety of functions? Classically, specificity was thought to be imparted by alternative splicing of the FGFRs, resulting in isoforms that bind specifically to a subset of the FGFs, and by different saccharide sequences in the heparan sulfate proteoglycan (HSPG) co-receptor. A growing number of noncanonical co-receptors such as integrins and neural cell adhesion molecule (NCAM) are now recognized as imparting additional complexity to classic FGFR signaling. This review will discuss the noncanonical FGFR ligands and speculate on the possibility that they provide additional and alternative means to determining the functional specificity of FGFR signaling. We will also discuss how invertebrate models such as C. elegans may advance our understanding of noncanonical FGFR signaling. Developmental Dynamics 238:277,293, 2009. © 2008 Wiley-Liss, Inc. [source]


    Shaking table model test on Shanghai World Financial Center Tower

    EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 4 2007
    Xilin Lu
    Abstract The height of 101-storey Shanghai World Financial Center Tower is 492m above ground making it possible the tallest building in the world when completed. Three parallel structural systems including mega-frame structure, reinforced concrete and braced steel services core and outrigger trusses, are combined to resist vertical and lateral loads. The building could be classified as a vertically irregular structure due to a number of stiffened and transfer stories in the building. Complexities related to structural system layout are mainly exhibited in the design of services core, mega-diagonals and outrigger trusses. According to Chinese Code, the height 190 m of the building clearly exceeds the stipulated maximum height of for a composite frame/reinforced concrete core building. The aspect ratio of height to width also exceeds the stipulated limit of 7 for seismic design intensity 7. A 1/50 scaled model is made and tested on shaking table under a series of one and two-dimensional base excitations with gradually increasing acceleration amplitudes. This paper presents the dynamic characteristics, the seismic responses and the failure mechanism of the structure. The test results demonstrate that the structural system is a good solution to withstand earthquakes. The inter-storey drift and the overall behaviour meet the requirements of Chinese Design Code. Furthermore, weak positions under seldom-occurred earthquakes of seismic design intensity 8 are found based on the visible damages on the testing model, and some corresponding suggestions are proposed for the engineering design of the structure under extremely strong earthquake. Copyright © 2006 John Wiley & Sons, Ltd. [source]


    The Politics of Belonging: Complexities of Identity in the Catalan Borderlands

    GEOGRAFISKA ANNALER SERIES B: HUMAN GEOGRAPHY, Issue 3 2001
    Jouni Hškli
    The rise of the European nation,state system profoundly influenced the map of linguistic and cultural minorities. Catalonia in northeastern Spain is no exception. The consolidation of the Spanish and French kingdoms during the sixteenth and seventeenth centuries left Catalan speakers without political and cultural sovereignty. Furthermore, in the Treaty of the Pyrenees of 1659, the Catalan homeland els PaÔsos Catalans was divided by the Franco,Spanish border. Today, Catalan culture and politics enjoy increasing latitude in both Spain and France. This has encouraged various forms of cross,border co,operation in the Catalan borderlands. It has also led many Catalan nationalists to expect still greater political autonomy. Some activists have voiced claims for independence and even the reincorporation of the Spanish (el Principat) and French Catalonias (Catalunya Nord). However, political tensions regarding the borderland's development exist between the local actors and the Spanish and French national governments, as well as between Catalan nationalists and the population at large. This article examines these tensions, first by looking at cross,border co,operation efforts in Catalonia, and second by assessing the visible markers of identity that Catalan nationalists have placed in the border landscapes. These are contrasted with the results of a survey charting the opinions and attitudes of ,ordinary' Catalans. The article argues that there are significant cleavages among Catalans, and that the era of the nation,states has left a legacy of complex loyalties at international frontiers. [source]


    Development of an optimization model for energy systems planning in the Region of Waterloo

    INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 11 2008
    Y. P. Cai
    Abstract In this study, a large-scale dynamic optimization model (University of Regina Energy Model, UREM) has been developed for supporting long-term energy systems planning in the Region of Waterloo. The model can describe energy management systems as networks of a series of energy flows, transferring extracted/imported energy resources to end users through a variety of conversion and transmission technologies over a number of periods. It can successfully incorporate optimization models, scenario development and policy analysis within a general framework. Complexities in energy management systems can be systematically reflected; thus, the applicability of the modeling process can be highly enhanced. Four scenarios (including a reference case) are considered based on different energy management policies and sustainable development strategies for in-depth analysis of interactions existing among energy, socio-economy and environment in the Region. Useful solutions for the planning of energy management systems have been generated, reflecting trade-offs among energy-related, environmental and economic considerations. They are helpful for supporting (a) adjustment or justification of the existing allocation patterns of energy resources and services, (b) allocations of renewable energy resources, (c) formulation of local policies regarding energy consumption, economic development and energy structure, and (d) analysis of interactions among economic cost, system efficiency, emission mitigation and energy-supply security. Results also indicate that UREM can help tackle dynamic and interactive characteristics of the energy management system in the Region of Waterloo and can address issues concerning cost-effective allocation of energy resources and services. Thus, it can be used by decision makers as an effective technique in examining and visualizing impacts of energy and environmental policies, regional/community development strategies and emission reduction measures within an integrated and dynamic framework. Copyright © 2008 John Wiley & Sons, Ltd. [source]


    Role of Structural Complexities of Septal Tissue in Maintaining Ventricular Fibrillation in Isolated, Perfused Canine Ventricle

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2001
    TAKANORI IKEDA M.D.
    Tissue Structure and VF.Introduction: It is unclear how the patterns of wavelet propagation during ventricular fibrillation (VF) vary between structurally different tissues. We hypothesized that the structural complexities of septal tissue influence the maintenance of reentrant wavelets in the ventricle. Methods and Results: Endocardial activation patterns during VF were analyzed in the isolated, perfused canine right ventricular (RV) free wall (n = 9), interventricular septum (n = 5), and left ventricular (LV) free wall (n = 6) using a computerized mapping system (2-mm resolution) with 120-msec consecutive windows. Each tissue sample was cut progressively to reduce the tissue mass until the VF was terminated. More wavelets were seen in the septa than in the RV and LV free walls at baseline (P = 0.004), and VF in the septa displayed a shorter cycle length than in the RV and LV free walls (P = 0.017). As the tissue mass decreased, VF became successively more organized in all regions: the number of wavelets decreased and the cycle length of VF lengthened. Single and "figure-of-eight" stationary, reentrant wavelets often were mapped after tissue mass reduction in the RV free walls and rarely in the LV free walls, but they were not observed in the septa. Less critical mass was required to maintain VF in the septa than in the RV and LV free walls (P = 0.0006). Gross anatomic and histologic examinations indicated that the tissue structure of the septa is more complex than that of the RV and LV free walls. Conclusion: VF activation patterns with progressive reduction of tissue mass differ for the septum and the ventricular free walls. The structural complexities of the septal tissue influence the maintenance of fibrillation in the ventricle. [source]


    Complexities of indigeneity and autochthony: An African example

    AMERICAN ETHNOLOGIST, Issue 1 2009
    Michaela Pelican
    ABSTRACT In this article, I deal with the complexities of "indigeneity" and "autochthony," two distinct yet closely interrelated concepts used by various actors in local, national, and international arenas in Africa and elsewhere. With the adoption of the Declaration on the Rights of Indigenous Peoples by the United Nations General Assembly in September 2007, hopes were high among activists and organizations that the precarious situation of many minority groups might be gradually improved. However, sharing the concerns of other scholars, I argue that discourses of indigeneity and autochthony are highly politicized, are subject to local and national particularities, and produce ambivalent, sometimes paradoxical, outcomes. My elaborations are based on in-depth knowledge of the case of the Mbororo in Cameroon, a pastoralist group and national minority recognized by the United Nations as an "indigenous people" although locally perceived as "strangers" and "migrants." For comparative purposes, and drawing on related studies, I integrate the Bagyeli and Baka (also known as Pygmies) of southern and southeastern Cameroon into my analysis, as they share the designation of indigenous people with the Mbororo and face similar predicaments. [indigeneity, autochthony, identity, United Nations, Cameroon] [source]


    Into the twilight zone: the complexities of mesopic vision and luminous efficiency

    OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 3 2006
    Andrew Stockman
    Abstract Of all the functions that define visual performance, the mesopic luminous efficiency function is probably the most complex and hardest to standardise or model. Complexities arise because of the substantial and often rapid visual changes that accompany the transition from scotopic to photopic vision. These are caused not only by the switch from rod to cone photoreceptors, but also by switches between different post-receptoral pathways through which the rod and cone signals are transmitted. In this review, we list several of the complexities of mesopic vision, such as rod,cone interactions, rod saturation, mixed photoreceptor spectral sensitivities, different rod and cone retinal distributions, and the changes in the spatial properties of the visual system as it changes from rod- to cone-mediated. Our main focus, however, is the enormous and often neglected temporal changes that occur in the mesopic range and their effect on luminous efficiency. Even before the transition from rod to cone vision is complete, a transition occurs within the rod system itself from a sluggish, sensitive post-receptoral pathway to a faster, less sensitive pathway. As a consequence of these complexities, any measure of mesopic performance will depend not only on the illumination level, but also on the spectral content of the stimuli used to probe performance, their retinal location, their spatial frequency content, and their temporal frequency content. All these should be considered when attempting to derive (or to apply) a luminous efficiency function for mesopic vision. [source]


    Bougainville and Papua New Guinea: Complexities of Secession in a Multi-ethnic Developing State

    POLITICAL STUDIES, Issue 4 2000
    Anthony Matthew
    The claims made by Bougainville's secessionist leaders correspond with five theoretical perspectives on the morality of secession , based, respectively, on notions of political consent, national identity, cultural preservation, distributive justice and territorial title. Each is tackled in turn, as a means to both assessing the justness of the Bougainvillean case, while also testing the limits of applicability of the moral perspectives themselves. Overall, it is concluded that the complexities of the Bougainville/Papua New Guinea case militate against outright separation. Rather, a balanced resolution of injustices is more likely to be attained by modifications to institutions and patterns of distribution within the existing state. Furthermore, this highly complex case throws up important challenges from which normative theory can profitably learn. [source]


    Complexities of conflict: the importance of considering social factors for effectively resolving human,wildlife conflict

    ANIMAL CONSERVATION, Issue 5 2010
    A. J. Dickman
    Abstract Human,wildlife conflict is one of the most critical threats facing many wildlife species today, and the topic is receiving increasing attention from conservation biologists. Direct wildlife damage is commonly cited as the main driver of conflict, and many tools exist for reducing such damage. However, significant conflict often remains even after damage has been reduced, suggesting that conflict requires novel, comprehensive approaches for long-term resolution. Although most mitigation studies investigate only the technical aspects of conflict reduction, peoples' attitudes towards wildlife are complex, with social factors as diverse as religious affiliation, ethnicity and cultural beliefs all shaping conflict intensity. Moreover, human,wildlife conflicts are often manifestations of underlying human,human conflicts, such as between authorities and local people, or between people of different cultural backgrounds. Despite evidence that social factors can be more important in driving conflict than wildlife damage incurred, they are often ignored in conflict studies. Developing a broader awareness of conflict drivers will advance understanding of the patterns and underlying processes behind this critical conservation issue. In this paper, I review a wide variety of case studies to show how social factors strongly influence perceptions of human,wildlife conflict, and highlight how mitigation approaches should become increasingly innovative and interdisciplinary in order to enable people to move from conflict towards coexistence. [source]


    Exploring the Structural Complexities of Metal,Metalloid Nanoparticles: The Case of Ni,B as Catalyst

    CHEMISTRY - A EUROPEAN JOURNAL, Issue 5 2009
    Junfeng Geng Dr.
    Abstract Understanding of the structural complexities of metal,metalloid nanoparticles is at the heart of several proposals for investigating the physical properties and practical applications of these bi-elemental nanomaterials. To date, the most widely studied metal,metalloid is the nickel,boron (Ni,B) system; however, the exact nature of the structure of the material itself has remained unclear. Herein we show our systematic investigations of the material in an attempt to reveal its fascinating nanostructure. The relation between its high catalytic activity and the ultrafine structure is explored, and the work has been further extended to the formation of colloidal Ni,B nanoparticles. The results presented in this work may represent a substantial progress toward a full understanding of the nickel,boron chemistry. [source]


    Theories, Therapies, and Taxpayers: On the Complexities of the Expressive Writing Paradigm

    CLINICAL PSYCHOLOGY: SCIENCE AND PRACTICE, Issue 2 2004
    James W. Pennebaker
    Although the expressive writing paradigm has generally produced positive health outcomes, a recurring puzzle concerns how and why it works. No single theory or theoretical perspective has convincingly explained its effectiveness. This may be attributable to the fact that expressive writing affects people on multiple levels,cognitive, emotional, social, and biological,making a single explanatory theory unlikely. In addition to addressing theory-relevant questions, researchers and therapists must now address when and with whom writing is most beneficial and, at the same time, evaluate if this (and other) intervention produces economically valuable outcomes. [source]


    Complexities and controversies in the management of low rectal cancer: Proceedings of the 3rd Pelican Surgical Symposium 2005

    COLORECTAL DISEASE, Issue 2006
    I. R. Daniels
    No abstract is available for this article. [source]


    System Complexity As a Measure of Safe Capacity for the Emergency Department

    ACADEMIC EMERGENCY MEDICINE, Issue 11 2006
    Daniel J. France PhD
    Objectives System complexity is introduced as a new measure of system state for the emergency department (ED). In its original form, the measure quantifies the uncertainty of demands on system resources. For application in the ED, the measure is being modified to quantify both workload and uncertainty to produce a single integrated measure of system state. Methods Complexity is quantified using an information-theoretic or entropic approach developed in manufacturing and operations research. In its original form, complexity is calculated on the basis of four system parameters: 1) the number of resources (clinicians and processing entities such as radiology and laboratory systems), 2) the number of possible work states for each resource, 3) the probability that a resource is in a particular work state, and 4) the probability of queue changes (i.e., where a queue is defined by the number of patients or patient orders being managed by a resource) during a specified time period. Results An example is presented to demonstrate how complexity is calculated and interpreted for a simple system composed of three resources (i.e., emergency physicians) managing varying patient loads. The example shows that variation in physician work states and patient queues produces different scores of complexity for each physician. It also illustrates how complexity and workload differ. Conclusions System complexity is a viable and technically feasible measurement for monitoring and managing surge capacity in the ED. [source]


    Managing Complexity: The Executive MBA at the Zollverein School

    DESIGN MANAGEMENT REVIEW, Issue 3 2007
    Andrej Kupetz President
    In this new and innovative program, management is viewed as a design task that engages the creative disciplines, as well as traditional skills in business and engineering. Andrej Kupetz, with students Martin Mangold and Miriam Selbeck, summarize the interdisciplinary nature of the curriculum, as well as its merging of theory and practice, and illustrate outcomes with the discussion of two real-world thesis projects. [source]


    Reducing Complexity in the Industrial Policy Debate

    DEVELOPMENT POLICY REVIEW, Issue 4 2007
    Hubert Schmitz
    A central concern of industrial policy is how to configure the relationship with the global economy. The manifold choices and pressures make this a difficult task for policy-makers. This article suggests a way of framing discussions between policy-makers, advisers and researchers, to help reduce complexity and find common ground. It demonstrates how different constellations of low/high challenge and support bring out the essence of different policy regimes, and how different constellations of narrow/wide technology and marketing gaps help identify the most plausible way forward. [source]


    Complexity can enhance stability in competitive systems

    ECOLOGY LETTERS, Issue 5 2001
    Ian D. Rozdilsky
    Empirical observations often indicate that complexity enhances stability, while most theoretical studies, such as May's (1972) classic paper, point to the opposite. Despite the wide generality of these latter theoretical analyses, our examination of the well-known competitive Lotka,Volterra system reveals that increasing complexity (measured in terms of connectance) can enhance species coexistence and persistence in model communities (measured in terms of their feasibility and stability). The high feasibility and stability found for tightly interconnected competitive subsystems might provide an explanation for the clumped structure in food webs. [source]


    Computability, Complexity and Constructivity in Economic Analysis.

    ECONOMICA, Issue 295 2007
    Edited by K. VELA VILLAPILLAI
    No abstract is available for this article. [source]


    Complexity and Educational Research: A critical reflection

    EDUCATIONAL PHILOSOPHY AND THEORY, Issue 1 2008
    Lesley Kuhn
    Abstract Judgements concerning proper or appropriate educational endeavour, methods of investigation and philosophising about education necessarily implicate perspectives, values, assumptions and beliefs. In recent years ideas from the complexity sciences have been utilised in many domains including psychology, economics, architecture, social science and education. This paper addresses questions concerning the appropriateness of utilising complexity science in educational research as well as issues relating to the ways in which complexity might be engaged. I suggest that, just like all human endeavour, approaches to research emerge out of discursive communities and can be understood as self-organising, dynamic and emergent over time. In this formulation, complexity represents one such newly emergent approach. I argue that it is important that researchers partake in critical and reflective discourse about the nature of education and conceptual frameworks, as well as about impacts and legacies of utilising complexity, so as to participate in and influence the ongoing emergence of educational endeavour. I conclude by suggesting a series of caveats for researchers considering using complexity in educational research. [source]


    Complexity and the Culture of Curriculum

    EDUCATIONAL PHILOSOPHY AND THEORY, Issue 1 2008
    William E. Doll
    Abstract This paper has two main foci: (1) the history of curriculum design, and (2) implications from the new sciences of chaos and complexity for the development of new forms of curriculum design and teaching implementation. Regarding the first focus, the paper posits that there exist,to use Wittgenstein's phrase,,family resemblances' between Peter Ramus' 16th century curriculum design and that of Ralph Tyler in the 20th century. While this 400-year linkage is by no means linear, there are overlapping strands from Ramus to Comenius to the Puritans to colonial New England to Horace Mann to Ralph Tyler. What unites these strands, all belonging to the Protestant Methodization movement that swept across northern Europe into colonial America and the USA, is the concept of Method. Taylor's ,time and motion' studies set the stage for Tyler's Basic Principles of curriculum design,those starting with set goals and concluding with measured assessment. The second focus draws on the new sciences of chaos and complexity to develop a different sense of curriculum and instruction,open, dynamic, relational, creative, and systems oriented. The paper concludes with an integration of the rational/scientific with the aesthetic/spiritual into a view of education and curriculum informed by complexity. [source]


    Complexity in Environmental Education1

    EDUCATIONAL PHILOSOPHY AND THEORY, Issue 2 2001
    Edgar GonzŠlez-Gaudiano
    First page of article [source]


    Natural Aging in Al-Mg-Si Alloys , A Process of Unexpected Complexity,

    ADVANCED ENGINEERING MATERIALS, Issue 7 2010
    John Banhart
    The natural aging behavior of pure ternary Al-Mg-Si alloys is investigated by measuring hardness, electrical resistivity and positron lifetime, as well as carrying out thermal analysis and atom probe microscopy. It is found that several distinct temporal stages of natural aging can be distinguished in which one of these quantities shows a characteristic behavior and that these times coincide for many of these measurements. The rate of change in the measured data is correlated with proposed solute dynamics during natural aging for both aging that takes place prior to artificial aging (natural pre-aging) and after artificial underaging (natural secondary aging) heat treatments. Controlling factors for solute dynamics are discussed. [source]