997 resultados para Graph-theoretical descriptors
Resumo:
Being able to innovate has become a critical capability for many contemporary organizations in an effort to sustain their operations in the long run. However, existing innovation models that attempt to guide organizations emphasize different aspects of innovation (e.g., products, services or business models), different stages of innovation (e.g., ideation, implementation or operation) or different skills (e.g., development or crowdsourcing) that are necessary to innovate, in turn creating isolated pockets of understanding about different aspects of innovation. In order to yield more predictable innovation outcomes organizations need to understand what exactly they need to focus on, what capabilities they need to have and what is necessary in order to take an idea to market. This paper aims at constructing a framework for innovation that contributes to this understanding. We will focus on a number of different stages in the innovation process and highlight different types and levels of organizational, technological, individual and process capabilities required to manage the organizational innovation process. Our work offers a comprehensive conceptualization of innovation as a multi-level process model, and provides a range of implications for further empirical and theoretical examination.
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Learning can allow individuals to increase their fitness in particular environments. The advantage to learning depends on the predictability of the environment and the extent to which animals can adjust their behaviour. Earlier general models have investigated when environmental predictability might favour the evolution of learning in foraging animals. Here, we construct a theoretical model that predicts the advantages to learning using a specific biological example: oviposition in the Lepidoptera. Our model includes environmental and behavioural complexities relevant to host selection in these insects and tests whether the predictions of the general models still hold. Our results demonstrate how the advantage of learning is maximised when within-generation variability is minimised (the local environment consists mainly of a single host plant species) and between-generation variability is maximised (different host plant species are the most common in different generations). We discuss how our results: (a) can be applied to recent empirical work in different lepidopteran species and (b) predict an important role of learning in lepidopteran agricultural pests.
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In this paper, we propose a semi-supervised approach of anomaly detection in Online Social Networks. The social network is modeled as a graph and its features are extracted to detect anomaly. A clustering algorithm is then used to group users based on these features and fuzzy logic is applied to assign degree of anomalous behavior to the users of these clusters. Empirical analysis shows effectiveness of this method.
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Information literacy has been a significant issue in the library community for many years. It is now being recognised as an important issue by the higher education community. This theoretical framework draws together important elements of the information literacy agenda specifically for tertiary educators and administrators. The frame-work examines three areas of primary concern: the possible outcomes of information literacy education (through outlining the characteristics of information literate people); the nature of information literacy education; and the potential role of stake-holders (including information services, faculty, staff developers and learning counsellors) in helping staff and students to be information literate. This theoretical framework forms part of the Griffith University Information Literacy Blueprint. The Blueprint was designed between June and August of 1994. The project, a quality initiative of the Division of Information Services, was led by Janice Rickards, University Librarian.
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This research project frames an emerging field – fashion curation – through a theoretical, historical, and practical enquiry. Recent decades have seen fashion curation grow rapidly as a form of praxis and an area of academic attention, predominantly in museums and universities. Within this context, two major models for conceptualising the role of the fashion curator have emerged: the institutional and the independent curator. This project proposes and applies a third model: the adjunct fashion curator. In developing this model my project seeks to move the growing dialogue around fashion curation away from exclusively focusing on the museum. By proposing a third curatorial model for fashion, this research draws on the past of fashion display and exhibition for its context, while simultaneously exploring the adjunct model through my curatorial practice. The impact of sites of display, the role of gender, and the relationship between art and fashion are explored as pivotal themes in the development of fashion curation and thus provide contextual grounding for the proposal of the adjunct curatorial model. Alongside a theoretical and historical account of fashion curation, I conduct a practice-led inquiry that explores these themes through five exhibition projects and one photographic series. I argue that the introduction and application of the adjunct model enables curatorial practitioners to sensitively work around the dominant museum model, and circumvent the divide between institutional and independent curation. Introducing the adjunct model allows the curator to develop personalised narratives relating to the experience of fashion and clothing as an exhibited phenomenon in a variety of institutional and non-institutional sites. Hence this research project contributes to a developing field by proposing a valuable and nuanced model for fashion curation.
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Electrostatic discharges have been identified as the most likely cause in a number of incidents of fire and explosion with unexplained ignitions. The lack of data and suitable models for this ignition mechanism creates a void in the analysis to quantify the importance of static electricity as a credible ignition mechanism. Quantifiable hazard analysis of the risk of ignition by static discharge cannot, therefore, be entirely carried out with our current understanding of this phenomenon. The study of electrostatics has been ongoing for a long time. However, it was not until the wide spread use of electronics that research was developed for the protection of electronics from electrostatic discharges. Current experimental models for electrostatic discharge developed for intrinsic safety with electronics are inadequate for ignition analysis and typically are not supported by theoretical analysis. A preliminary simulation and experiment with low voltage was designed to investigate the characteristics of energy dissipation and provided a basis for a high voltage investigation. It was seen that for a low voltage the discharge energy represents about 10% of the initial capacitive energy available and that the energy dissipation was within 10 ns of the initial discharge. The potential difference is greatest at the initial break down when the largest amount of the energy is dissipated. The discharge pathway is then established and minimal energy is dissipated as energy dissipation becomes greatly influenced by other components and stray resistance in the discharge circuit. From the initial low voltage simulation work, the importance of the energy dissipation and the characteristic of the discharge were determined. After the preliminary low voltage work was completed, a high voltage discharge experiment was designed and fabricated. Voltage and current measurement were recorded on the discharge circuit allowing the discharge characteristic to be recorded and energy dissipation in the discharge circuit calculated. Discharge energy calculations show consistency with the low voltage work relating to discharge energy with about 30-40% of the total initial capacitive energy being discharged in the resulting high voltage arc. After the system was characterised and operation validated, high voltage ignition energy measurements were conducted on a solution of n-Pentane evaporating in a 250 cm3 chamber. A series of ignition experiments were conducted to determine the minimum ignition energy of n-Pentane. The data from the ignition work was analysed with standard statistical regression methods for tests that return binary (yes/no) data and found to be in agreement with recent publications. The research demonstrates that energy dissipation is heavily dependent on the circuit configuration and most especially by the discharge circuit's capacitance and resistance. The analysis established a discharge profile for the discharges studied and validates the application of this methodology for further research into different materials and atmospheres; by systematically looking at discharge profiles of test materials with various parameters (e.g., capacitance, inductance, and resistance). Systematic experiments looking at the discharge characteristics of the spark will also help understand the way energy is dissipated in an electrostatic discharge enabling a better understanding of the ignition characteristics of materials in terms of energy and the dissipation of that energy in an electrostatic discharge.
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This paper conceptualizes knowledge governance (KG) in project-based organizations (PBOs) and its methodological approaches for empirical investigation. Three key contributions towards a multi-faceted view of KG and an understanding of KG in PBOs are advanced. These contributions include a definition of KG in PBOs, a conceptual framework to investigate KG and a methodological framework for empirical inquiry into KG in PBO settings. Our definition highlights the contingent nature of KG processes in relation to their organizational context. The conceptual framework addresses macro- and micro-level elements of KG and their interaction. The methodological framework proposes five different research approaches, structured by differentiation and integration of various ontological and epistemological stances. Together these contributions provide a novel platform for understanding KG in PBOs and developing new insights into the design and execution of research on KG within PBOs.
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A people-to-people matching system (or a match-making system) refers to a system in which users join with the objective of meeting other users with the common need. Some real-world examples of these systems are employer-employee (in job search networks), mentor-student (in university social networks), consume-to-consumer (in marketplaces) and male-female (in an online dating network). The network underlying in these systems consists of two groups of users, and the relationships between users need to be captured for developing an efficient match-making system. Most of the existing studies utilize information either about each of the users in isolation or their interaction separately, and develop recommender systems using the one form of information only. It is imperative to understand the linkages among the users in the network and use them in developing a match-making system. This study utilizes several social network analysis methods such as graph theory, small world phenomenon, centrality analysis, density analysis to gain insight into the entities and their relationships present in this network. This paper also proposes a new type of graph called “attributed bipartite graph”. By using these analyses and the proposed type of graph, an efficient hybrid recommender system is developed which generates recommendation for new users as well as shows improvement in accuracy over the baseline methods.
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The purpose of this paper is to present a theoretical framework to investigate the relationship between work motivation, organisational commitment and professional commitment in temporary organisations. Through a review of theory, we contend that work motivation has two major patterns — internal motivation (which includes intrinsic, need-based and self-deterministic theories), and external motivation (which includes cognitive or process-based theories of motivation) through which it has been investigated. We also hold the nature of employee commitment to be of three types — affective, continuance and normative. This commitment may be towards either the organisation or the profession. A literature review revealed that the characteristics of the temporary organisation — specifically tenure and task — regulate the relationship between work motivation, organisational commitment and professional commitment. Testable propositions are presented.
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The complex [1,2-bis(di-tert-butylphosphanyl)ethane-[kappa]2P,P']diiodidonickel(II), [NiI2(C18H40P2] or (dtbpe-[kappa]2P)NiI2, [dtbpe is 1,2-bis(di-tert-butylphosphanyl)ethane], is bright blue-green in the solid state and in solution, but, contrary to the structure predicted for a blue or green nickel(II) bis(phosphine) complex, it is found to be close to square planar in the solid state. The solution structure is deduced to be similar, because the optical spectra measured in solution and in the solid state contain similar absorptions. In solution at room temperature, no 31P{1H} NMR resonance is observed, but the very small solid-state magnetic moment at temperatures down to 4 K indicates that the weak paramagnetism of this nickel(II) complex can be ascribed to temperature independent paramagnetism, and that the complex has no unpaired electrons. The red [1,2-bis(di-tert-butylphosphanyl)ethane-[kappa]2P,P']dichloridonickel(II), [NiCl2(C18H40P2] or (dtbpe-[kappa]2P)NiCl2, is very close to square planar and very weakly paramagnetic in the solid state and in solution, while the maroon [1,2-bis(di-tert-butylphosphanyl)ethane-[kappa]2P,P']dibromidonickel(II), [NiBr2(C18H40P2] or (dtbpe-[kappa]2P)NiBr2, is isostructural with the diiodide in the solid state, and displays paramagnetism intermediate between that of the dichloride and the diiodide in the solid state and in solution. Density functional calculations demonstrate that distortion from an ideal square plane for these complexes occurs on a flat potential energy surface. The calculations reproduce the observed structures and colours, and explain the trends observed for these and similar complexes. Although theoretical investigation identified magnetic-dipole-allowed excitations that are characteristic for temperature-independent paramagnetism (TIP), theory predicts the molecules to be diamagnetic.
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The purpose of this paper is to present theoretical lenses that explain the relation between work motivation and project management success in case of temporary organizations such as projects. This paper is a part of the larger research study that first empirically identifies the constructs of work motivation in case of temporary organizations, and then empirically determines the relation between work motivation, and project management success. In the current paper, we have briefly reviewed the theories of work motivation from the work design school. These theories are predominantly drawn from the industrial/ organizational psychology literature. Then, we have considered the recent research on Nine Schools of Project Management as a point of departure to review theory on project management success. These theoretical perspectives are drawn from project management literature. We then illustrate the points of overlap for the theories drawn from these two disciplines. This review helps us to position our research study within the industrial/ organizational psychology, and project management literature as a cross-discipline study.
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Whole-body cryotherapy (WBC) involves short exposures to air temperatures below –100°C. WBC is increasingly accessible to athletes, and is purported to enhance recovery after exercise and facilitate rehabilitation postinjury. Our objective was to review the efficacy and effectiveness of WBC using empirical evidence from controlled trials. We found ten relevant reports; the majority were based on small numbers of active athletes aged less than 35 years. Although WBC produces a large temperature gradient for tissue cooling, the relatively poor thermal conductivity of air prevents significant subcutaneous and core body cooling. There is weak evidence from controlled studies that WBC enhances antioxidant capacity and parasympathetic reactivation, and alters inflammatory pathways relevant to sports recovery. A series of small randomized studies found WBC offers improvements in subjective recovery and muscle soreness following metabolic or mechanical overload, but little benefit towards functional recovery. There is evidence from one study only that WBC may assist rehabilitation for adhesive capsulitis of the shoulder. There were no adverse events associated with WBC; however, studies did not seem to undertake active surveillance of predefined adverse events. Until further research is available, athletes should remain cognizant that less expensive modes of cryotherapy, such as local ice-pack application or cold-water immersion, offer comparable physiological and clinical effects to WBC.
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Indigenous media around the globe have expanded considerably in recent years, a process that has also led to an increase in the number of Indigenous news organisations. Yet, research into Indigenous news and journalism is still rare, with mostly individual case studies having been undertaken in different parts of the globe. Drawing on existing research gathered from a variety of global contexts, this paper theorises five main dimensions which can help us think about and empirically examine Indigenous journalism culture. They include: the empowerment role of Indigenous journalism; the ability to offer a counter-narrative to mainstream media reporting; journalism’s role in language revitalisation; reporting through a culturally appropriate framework; and the watchdog function of Indigenous journalism. These dimensions are discussed in some detail, in an attempt to guide future studies into the structures, roles, practices and products of Indigenous journalism across the globe.
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Purpose This work introduces the concept of very small field size. Output factor (OPF) measurements at these field sizes require extremely careful experimental methodology including the measurement of dosimetric field size at the same time as each OPF measurement. Two quantifiable scientific definitions of the threshold of very small field size are presented. Methods A practical definition was established by quantifying the effect that a 1 mm error in field size or detector position had on OPFs, and setting acceptable uncertainties on OPF at 1%. Alternatively, for a theoretical definition of very small field size, the OPFs were separated into additional factors to investigate the specific effects of lateral electronic disequilibrium, photon scatter in the phantom and source occlusion. The dominant effect was established and formed the basis of a theoretical definition of very small fields. Each factor was obtained using Monte Carlo simulations of a Varian iX linear accelerator for various square field sizes of side length from 4 mm to 100 mm, using a nominal photon energy of 6 MV. Results According to the practical definition established in this project, field sizes < 15 mm were considered to be very small for 6 MV beams for maximal field size uncertainties of 1 mm. If the acceptable uncertainty in the OPF was increased from 1.0 % to 2.0 %, or field size uncertainties are 0.5 mm, field sizes < 12 mm were considered to be very small. Lateral electronic disequilibrium in the phantom was the dominant cause of change in OPF at very small field sizes. Thus the theoretical definition of very small field size coincided to the field size at which lateral electronic disequilibrium clearly caused a greater change in OPF than any other effects. This was found to occur at field sizes < 12 mm. Source occlusion also caused a large change in OPF for field sizes < 8 mm. Based on the results of this study, field sizes < 12 mm were considered to be theoretically very small for 6 MV beams. Conclusions Extremely careful experimental methodology including the measurement of dosimetric field size at the same time as output factor measurement for each field size setting and also very precise detector alignment is required at field sizes at least < 12 mm and more conservatively < 15 mm for 6 MV beams. These recommendations should be applied in addition to all the usual considerations for small field dosimetry, including careful detector selection.