961 resultados para hierarchical structure


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Introduction This paper reports on university students' experiences of learning information literacy. Method Phenomenography was selected as the research approach as it describes the experience from the perspective of the study participants, which in this case is a mixture of undergraduate and postgraduate students studying education at an Australian university. Semi-structured, one-on-one interviews were conducted with fifteen students. Analysis The interview transcripts were iteratively reviewed for similarities and differences in students' experiences of learning information literacy. Categories were constructed from an analysis of the distinct features of the experiences that students reported. The categories were grouped into a hierarchical structure that represents students' increasingly sophisticated experiences of learning information literacy. Results The study reveals that students experience learning information literacy in six ways: learning to find information; learning a process to use information; learning to use information to create a product; learning to use information to build a personal knowledge base; learning to use information to advance disciplinary knowledge; and learning to use information to grow as a person and to contribute to others. Conclusions Understanding the complexity of the concept of information literacy, and the collective and diverse range of ways students experience learning information literacy, enables academics and librarians to draw on the range of experiences reported by students to design academic curricula and information literacy education that targets more powerful ways of learning to find and use information.

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This paper presents a new approach to web browsing in situ- ations where the user can only provide the device with a sin- gle input command device (switch). Switches have been de- veloped for example for people with locked-in syndrome and are used in combination with scanning to navigate virtual keyboards and desktop interfaces. Our proposed approach leverages the hierarchical structure of webpages to operate a multi-level scan of actionable elements of webpages (links or form elements). As there are a few methods already exist- ing to facilitate browsing under these conditions, we present a theoretical usability evaluation of our approach in com- parison to the existing ones, which takes into account the average time taken to reach any part of a web page (such as a link or a form) but also the number of clicks necessary to reach the goal. We argue that these factors contribute together to usability. In addition, we propose that our ap- proach presents additional usability benefits.

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Purpose Health service quality is an important determinant for health service satisfaction and behavioral intentions. The purpose of this paper is to investigate requirements of e‐health services and to develop a measurement model to analyze the construct of “perceived e‐health service quality.” Design/methodology/approach The paper adapts the C‐OAR‐SE procedure for scale development by Rossiter. The focal aspect is the “physician‐patient relationship” which forms the core dyad in the healthcare service provision. Several in‐depth interviews were conducted in Switzerland; first with six patients (as raters), followed by two experts of the healthcare system (as judges). Based on the results and an extensive literature research, the classification of object and attributes is developed for this model. Findings The construct e‐health service quality can be described as an abstract formative object and is operationalized with 13 items: accessibility, competence, information, usability/user friendliness, security, system integration, trust, individualization, empathy, ethical conduct, degree of performance, reliability, and ability to respond. Research limitations/implications Limitations include the number of interviews with patients and experts as well as critical issues associated with C‐OAR‐SE. More empirical research is needed to confirm the quality indicators of e‐health services. Practical implications Health care providers can utilize the results for the evaluation of their service quality. Practitioners can use the hierarchical structure to measure service quality at different levels. The model provides a diagnostic tool to identify poor and/or excellent performance with regard to the e‐service delivery. Originality/value The paper contributes to knowledge with regard to the measurement of e‐health quality and improves the understanding of how customers evaluate the quality of e‐health services.

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A facile and up-scalable wet-mechanochemical process is designed for fabricating ultra-fine SnO2 nanoparticles anchored on graphene networks for use as anode materials for sodium ion batteries. A hierarchical structure of the SnO2@graphene composite is obtained from the process. The resultant rechargeable SIBs achieved high rate capability and good cycling stability.

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This work offers a novel interpretation of David Hume’s (1711–1776) conception of the conjectural development of civil society and artificial moral institutions. It focuses on the social elements of Hume’s Treatise of human nature (1739–40) and the necessary connection between science of man and politeness, civilised monarchies, social distance and hierarchical structure of civil society. The study incorporates aspects of intellectual history, history of philosophy and book history. In order to understand David Hume’s thinking, the intellectual development of Bernard Mandeville (1670–1733) needs to be accounted for. When put into a historical perspective, the moral, political and social components of Treatise of human nature can be read in the context of a philosophical tradition, in which Mandeville plays a pivotal role. A distinctive character of Mandeville and Hume’s account of human nature and moral institutions was the introduction of a simple distinction between self-love and self-liking. The symmetric passions of self-interest and pride can only be controlled by the corresponding moral institutions. This is also the way in which we can say that moral institutions are drawn from human nature. In the case of self-love or self-interest, the corresponding moral institution is justice. Respectively, concerning self-liking or pride the moral institution is politeness. There is an explicit analogy between these moral institutions. If we do not understand this analogy, we do not understand the nature of either justice or politeness. The present work is divided into two parts. In the first part, ‘Intellectual development of Bernard Mandeville’, it is argued that the relevance of the paradigmatic change in Mandeville’s thinking has been missed. It draws a picture of Mandeville turning from the Hobbism of The Fable of the Bees to an original theory of civil society put forward in his later works. In order to make this change more apparent, Mandeville’s career and the publishing history of The Fable of the Bees are examined comprehensively. This interpretation, based partly on previously unknown sources, challenges F. B. Kaye’s influential decision to publish the two parts of The Fable of the Bees as a uniform work of two volumes. The main relevance, however, of the ‘Intellectual development of Mandeville’ is to function as the context for the young Hume. The second part of the work, ‘David Hume and Greatness of mind’, explores in philosophical detail the social theory of the Treatise and politics and the science of man in his Essays. This part will also reveal the relevance of Greatness of mind as a general concept for David Hume’s moral and political philosophy.

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Maila Pylkkönen (1931 1986) was one of the most important modernist poets in Finland and a central figure in developing the dramatic monologue in Finnish literature. The study examines Pylkkönen s poetic work Arvo. Vanhaäiti puhuu runonsa (Value. An old woman speaks her poem, 1959) as an example of the dramatic monologue, approaching it from three perspectives: its generic features and background, and the poetic framework to which it connects in the context of Pylkkönen s poetry. In addition to methods of literary scholarship, the poetic analysis benefits from a linguistic approach. The study shows that the dramatic monologue genre drives Pylkkönen s first work, Klassilliset tunteet (Classical feelings, 1957), in a context of finding poetic identity, characterised by the expression to be the words of a living creature . The study demonstrates that important generic features of the dramatic monologue, namely, a poem representing a speech-event and a hierarchical structure, are also Arvo s most significant generic features. Arvo s poems as speech-events are examined for their internal progressive, pragmatic unity constructed through single line units; for their function as narratives dealing with the life story of an old woman, Arvo s speaker; and from the perspective of the communication between the old woman and the poems other characters. Arvo s speech-events can also be seen as semantic shifts from one poem to another: the poems construct semantic stages representing different phases of the old woman s life. The study demonstrates that analysis of Arvo s hierarchical structure, that is, the relationship between the speaker and the rhetorical levels, reveals the work s structural and ideological wholeness by focusing on the old woman s emotions: longing, loneliness and alienation from the world. In other words, the contradictions between the explicit level of the speaker and an implied rhetorical level open up the tragedy of an old woman s daily life. Study of Arvo s hierarchical structure also highlights the special position of the reader in the framework of a dramatic monologue. The elements of a dramatic present in which the old woman s emotions are conveyed, an italicized opening poem, and the work s title Value invite the reader to consider Arvo as a structural and ideological whole. The function of Arvo s hierarchical structure is to ask the reader to recognise the hopelessness of the old woman s situation, understand it, and even identify with it.

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In the absence of specific treatable mutations, platinum-based chemotherapy remains the gold standard of treatment for lung cancer patients. However, 5-year survival rates remain poor due to the development of resistance and eventual relapse. Resistance to conventional cytotoxic therapies presents a significant clinical challenge in the treatment of this disease. The cancer stem cell (CSC) hypothesis suggests that tumors are arranged in a hierarchical structure, with the presence of a small subset of stem-like cells that are responsible for tumor initiation and growth. This CSC population has a number of key properties such as the ability to asymmetrically divide, differentiate and self-renew, in addition to having increased intrinsic resistance to therapy. While cytotoxic chemotherapy kills the bulk of tumor cells, CSCs are spared and have the ability to recapitulate the heterogenic tumor mass. The identification of lung CSCs and their role in tumor biology and treatment resistance may lead to innovative targeted therapies that may ultimately improve clinical outcomes in lung cancer patients. This review will focus on lung CSC markers, their role in resistance and their relevance as targets for future therapies.

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Action, Power and Experience in Organizational Change - A Study of Three Major Corporations This study explores change management and resistance to change as social activities and power displays through worker experiences in three major Finnish corporations. Two important sensitizing concepts were applied. Firstly, Richard Sennett's perspective on work in the new form of capitalism, and its shortcomings - the lack of commitment and freedom accompanied by the disruption to lifelong career planning and the feeling of job insecurity - offered a fruitful starting point for a critical study. Secondly, Michel Foucault's classical concept of power, treated as anecdotal, interactive and nonmeasurable, provided tools for analyzing change-enabling and resisting acts. The study bridges the gap between management and social sciences. The former have usually concentrated on leadership issues, best practices and goal attainment, while the latter have covered worker experiences, power relations and political conflicts. The study was motivated by three research questions. Firstly, why people resist or support changes in their work, work environment or organization, and the kind of analyses these behavioural choices are based on. Secondly, the kind of practical forms which support for, and resistance to change take, and how people choose the different ways of acting. Thirdly, how the people involved experience and describe their own subject position and actions in changing environments. The examination focuses on practical interpretations and action descriptions given by the members of three major Finnish business organizations. The empirical data was collected during a two-year period in the Finnish Post Corporation, the Finnish branch of Vattenfal Group, one of the leading European energy companies, and the Mehiläinen Group, the leading private medical service provider in Finland. It includes 154 non-structured thematic interviews and 309 biographies concentrating on personal experiences of change. All positions and organizational levels were represented. The analysis was conducted using the grounded theory method introduced by Straus and Corbin in three sequential phases, including open, axial and selective coding processes. As a result, there is a hierarchical structure of categories, which is summarized in the process model of change behaviour patterns. Key ingredients are past experiences and future expectations which lead to different change relations and behavioural roles. Ultimately, they contribute to strategic and tactical choices realized as both public and hidden forms of action. The same forms of action can be used in both supporting and resisting change, and there are no specific dividing lines either between employer and employee roles or between different hierarchical positions. In general, however, it is possible to conclude that strategic choices lead more often to public forms of action, whereas tactical choices result in hidden forms. The primary goal of the study was to provide knowledge which has practical applications in everyday business life, HR and change management. The results, therefore, are highly applicable to other organizations as well as to less change-dominated situations, whenever power relations and conflicting interests are present. A sociological thesis on classical business management issues can be of considerable value in revealing the crucial social processes behind behavioural patterns. Keywords: change management, organizational development, organizational resistance, resistance to change, change management, labor relations, organization, leadership

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The goals of this article are to integrate action regulation theory (ART) with the lifespan developmental perspective and to outline tenets of a new metatheory of work and aging. The action regulation across the adult lifespan (ARAL) theory explains how workers influence, and are influenced by, their environment across different time spans. First, the basic concepts of ART are described, including the sequential and hierarchical structure of actions, complete tasks and actions, foci of action regulation, and the action-regulating mental model. Second, principles of the lifespan developmental perspective are delineated, including development as a lifelong and multidirectional process, the joint occurrence of gains and losses, intraindividual plasticity, historical embeddedness, and contextualism. Third, propositions of ARAL theory are derived by analyzing workers’ action regulation from a lifespan developmental perspective (i.e., effects of aging on action regulation), and by analyzing aging and development in the work context from an ART perspective (i.e., effects of action regulation on age-related changes in cognition and personality). Fourth, we develop further propositions to integrate ART with lifespan theories of motivation and socioemotional experience. Finally, we discuss implications for future research and practice based on ARAL theory.

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A number of neural network models, in which fixed-point and limit-cycle attractors of the underlying dynamics are used to store and associatively recall information, are described. In the first class of models, a hierarchical structure is used to store an exponentially large number of strongly correlated memories. The second class of models uses limit cycles to store and retrieve individual memories. A neurobiologically plausible network that generates low-amplitude periodic variations of activity, similar to the oscillations observed in electroencephalographic recordings, is also described. Results obtained from analytic and numerical studies of the properties of these networks are discussed.

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Clock synchronisation is an important requirement for various applications in wireless sensor networks (WSNs). Most of the existing clock synchronisation protocols for WSNs use some hierarchical structure that introduces an extra overhead due to the dynamic nature of WSNs. Besides, it is difficult to integrate these clock synchronisation protocols with sleep scheduling scheme, which is a major technique to conserve energy. In this paper, we propose a fully distributed peer-to-peer based clock synchronisation protocol, named Distributed Clock Synchronisation Protocol (DCSP), using a novel technique of pullback for complete sensor networks. The pullback technique ensures that synchronisation phases of any pair of clocks always overlap. We have derived an exact expression for a bound on maximum synchronisation error in the DCSP protocol, and simulation study verifies that it is indeed less than the computed upper bound. Experimental study using a few TelosB motes also verifies that the pullback occurs as predicted.

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Despite the complexity of biological networks, we find that certain common architectures govern network structures. These architectures impose fundamental constraints on system performance and create tradeoffs that the system must balance in the face of uncertainty in the environment. This means that while a system may be optimized for a specific function through evolution, the optimal achievable state must follow these constraints. One such constraining architecture is autocatalysis, as seen in many biological networks including glycolysis and ribosomal protein synthesis. Using a minimal model, we show that ATP autocatalysis in glycolysis imposes stability and performance constraints and that the experimentally well-studied glycolytic oscillations are in fact a consequence of a tradeoff between error minimization and stability. We also show that additional complexity in the network results in increased robustness. Ribosome synthesis is also autocatalytic where ribosomes must be used to make more ribosomal proteins. When ribosomes have higher protein content, the autocatalysis is increased. We show that this autocatalysis destabilizes the system, slows down response, and also constrains the system’s performance. On a larger scale, transcriptional regulation of whole organisms also follows architectural constraints and this can be seen in the differences between bacterial and yeast transcription networks. We show that the degree distributions of bacterial transcription network follow a power law distribution while the yeast network follows an exponential distribution. We then explored the evolutionary models that have previously been proposed and show that neither the preferential linking model nor the duplication-divergence model of network evolution generates the power-law, hierarchical structure found in bacteria. However, in real biological systems, the generation of new nodes occurs through both duplication and horizontal gene transfers, and we show that a biologically reasonable combination of the two mechanisms generates the desired network.

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Fluid flow in biological tissues is important in both mechanical and biological contexts. Given the hierarchical nature of tissues, there are varying length scales at which time-dependent mechanical behavior due to fluid flow may be exhibited. Here, spherical nanoindentation and microindentation testings are used for the characterization of length scale effects in the mechanical response of hydrated tissues. Although elastic properties were consistent across length scales, there was a substantial difference between the time-dependent mechanical responses for large and small contact radii in the same tissue specimens. This difference was far more obvious when poroelastic analysis was used instead of viscoelastic analysis. Overall, indentation testing is a fast and robust technique for characterizing the hierarchical structure of biological materials from nanometer to micrometer length scales and is capable of making quantitative material property measurements to do with fluid flow. © 2011 Materials Research Society.

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Understanding and controlling the hierarchical self-assembly of carbon nanotubes (CNTs) is vital for designing materials such as transparent conductors, chemical sensors, high-performance composites, and microelectronic interconnects. In particular, many applications require high-density CNT assemblies that cannot currently be made directly by low-density CNT growth, and therefore require post-processing by methods such as elastocapillary densification. We characterize the hierarchical structure of pristine and densified vertically aligned multi-wall CNT forests, by combining small-angle and ultra-small-angle x-ray scattering (USAXS) techniques. This enables the nondestructive measurement of both the individual CNT diameter and CNT bundle diameter within CNT forests, which are otherwise quantified only by delicate and often destructive microscopy techniques. Our measurements show that multi-wall CNT forests grown by chemical vapor deposition consist of isolated and bundled CNTs, with an average bundle diameter of 16 nm. After capillary densification of the CNT forest, USAXS reveals bundles with a diameter 4 m, in addition to the small bundles observed in the as-grown forests. Combining these characterization methods with new CNT processing methods could enable the engineering of macro-scale CNT assemblies that exhibit significantly improved bulk properties. © 2011 American Institute of Physics.

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A novel corrugated composite core, referred to as a hierarchical corrugation, has been developed and tested experimentally. Hierarchical corrugations exhibit a range of different failure modes depending on the geometrical properties and the material properties of the structures. In order to understand the different failure modes the analytical strength model, developed in part 1 of this paper, was used to make collapse mechanism maps for the different corrugation configurations. If designed correctly, the hierarchical structures can have more than 7 times higher weight specific strength compared to its monolithic counter part. The difference in strength arises mainly from the increase in buckling resistance of the sandwich core members compared to the monolithic version. The highest difference in strength is seen for core configurations with low overall density. As the density of the core increases, the monolithic core members get stockier and more resistant to buckling and thus the benefits of the hierarchical structure reduces. © 2008 Elsevier Ltd. All rights reserved.