959 resultados para collaborative networks
Resumo:
Artificial neural network (ANN) learning methods provide a robust and non-linear approach to approximating the target function for many classification, regression and clustering problems. ANNs have demonstrated good predictive performance in a wide variety of practical problems. However, there are strong arguments as to why ANNs are not sufficient for the general representation of knowledge. The arguments are the poor comprehensibility of the learned ANN, and the inability to represent explanation structures. The overall objective of this thesis is to address these issues by: (1) explanation of the decision process in ANNs in the form of symbolic rules (predicate rules with variables); and (2) provision of explanatory capability by mapping the general conceptual knowledge that is learned by the neural networks into a knowledge base to be used in a rule-based reasoning system. A multi-stage methodology GYAN is developed and evaluated for the task of extracting knowledge from the trained ANNs. The extracted knowledge is represented in the form of restricted first-order logic rules, and subsequently allows user interaction by interfacing with a knowledge based reasoner. The performance of GYAN is demonstrated using a number of real world and artificial data sets. The empirical results demonstrate that: (1) an equivalent symbolic interpretation is derived describing the overall behaviour of the ANN with high accuracy and fidelity, and (2) a concise explanation is given (in terms of rules, facts and predicates activated in a reasoning episode) as to why a particular instance is being classified into a certain category.
Resumo:
Web is a powerful hypermedia-based information retrieval mechanism that provides a user-friendly access across all major computer platforms connected over Internet. This paper demonstrates the application of Web technology when used as an educational delivery tool. It also reports on the development of a prototype electronic publishing project where Web technology was used to deliver power engineering educational resources. The resulting hyperbook will contain diverse teaching resources such as hypermedia-based modular educational units and computer simulation programs that are linked in a meaningful and structured way. The use of Web for disseminating information of this nature has many advantages that cannot possibly be achieved otherwise. PREAMBLE The continual increase of low-cost functionality available in desktop computing has opened up a new possibility in learning within a wider educational framework. This technology also is supported by enhanced features offered by new and ...
Resumo:
Geographic information is increasingly being touted for use in research and industrial projects. While the technology is now available and affordable, there is a lack of easy to use software that takes advantage of geographic information. This is an important problem because users are often researchers or scientists who have insufficient software skills, and by providing applications that are easier to use, time and financial resources can be taken from training and be better applied to the actual research and development work. A solution for this problem must cater for the user and research needs. In particular it must allow for mobile operation for fieldwork, flexibility or customisability of data input, sharing of data with other tools and collaborative capabilities for the usual teamwork environment. This thesis has developed a new architecture and data model to achieve the solution. The result is the Mobile Collaborative Annotation framework providing an implementation of the new architecture and data model. Mobile Collaborative Mapping implements the framework as a Web 2.0 mashup rich internet application and has proven to be an effective solution through its positive application to a case study with fieldwork scientists. This thesis has contributed to research into mobile computing, collaborative computing and geospatial systems by creating a simpler entry point to mobile geospatial applications, enabling simplified collaboration and providing tangible time savings.
Analytical modeling and sensitivity analysis for travel time estimation on signalized urban networks
Resumo:
This paper presents a model for estimation of average travel time and its variability on signalized urban networks using cumulative plots. The plots are generated based on the availability of data: a) case-D, for detector data only; b) case-DS, for detector data and signal timings; and c) case-DSS, for detector data, signal timings and saturation flow rate. The performance of the model for different degrees of saturation and different detector detection intervals is consistent for case-DSS and case-DS whereas, for case-D the performance is inconsistent. The sensitivity analysis of the model for case-D indicates that it is sensitive to detection interval and signal timings within the interval. When detection interval is integral multiple of signal cycle then it has low accuracy and low reliability. Whereas, for detection interval around 1.5 times signal cycle both accuracy and reliability are high.
Resumo:
This paper presents a methodology for estimation of average travel time on signalized urban networks by integrating cumulative plots and probe data. This integration aims to reduce the relative deviations in the cumulative plots due to midlink sources and sinks. During undersaturated traffic conditions, the concept of a virtual probe is introduced, and therefore, accurate travel time can be obtained when a real probe is unavailable. For oversaturated traffic conditions, only one probe per travel time estimation interval—360 s or 3% of vehicles traversing the link as a probe—has the potential to provide accurate travel time.
Resumo:
Voltage Unbalance (VU) is a power quality issue arising within the low voltage residential distribution networks due to the random location and rating of single-phase rooftop photovoltaic cells (PVs). In this paper, an analysis has been carried out to investigate how PV installations, their random location and power generation capacity can cause an increase in VU. Several efficient practical methods are discussed for VU reduction. Based on this analysis, it has been shown that the installation of a DSTATCOM can reduce VU. In this paper, the best possible location for DSTATCOM and its efficient control method to reduce VU will be presented. The results are verified through PSCAD/EMTDC and Monte Carlo simulations.
Resumo:
A collaborative approach to home care (HC) delivery for older clients has taken centre stage (Nies, 2006). In Finland, public home help and home health care services have been combined to form the home care unit, whose goal is to provide a collaborative approach to care delivery through cooperation and sharing of responsibilities. In this model, the general practitioner (GP), home care nurses (HCN) and home help workers (HHW) care for shared clients. GPs and HCNs provide health care, such as monitoring of clients’ health status, and HHWs assist with personal care tasks such as dressing, washing and meal preparation. As the needs of older clients are multiple, collaboration is needed as one professional group cannot take sole responsibility (Nies, 2006). This paper reports on a study undertaken to examine home care unit care providers’ perspectives of the collaborative approach to HC delivery for older clients.
Resumo:
Neural networks (NNs) are discussed in connection with their possible use in induction machine drives. The mathematical model of the NN as well as a commonly used learning algorithm is presented. Possible applications of NNs to induction machine control are discussed. A simulation of an NN successfully identifying the nonlinear multivariable model of an induction-machine stator transfer function is presented. Previously published applications are discussed, and some possible future applications are proposed.
Resumo:
The use of artificial neural networks (ANNs) to identify and control induction machines is proposed. Two systems are presented: a system to adaptively control the stator currents via identification of the electrical dynamics, and a system to adaptively control the rotor speed via identification of the mechanical and current-fed system dynamics. Both systems are inherently adaptive as well as self-commissioning. The current controller is a completely general nonlinear controller which can be used together with any drive algorithm. Various advantages of these control schemes over conventional schemes are cited, and the combined speed and current control scheme is compared with the standard vector control scheme
Resumo:
This paper proposes the use of artificial neural networks (ANNs) to identify and control an induction machine. Two systems are presented: a system to adaptively control the stator currents via identification of the electrical dynamics; and a system to adaptively control the rotor speed via identification of the mechanical and current-fed system dynamics. Various advantages of these control schemes over other conventional schemes are cited and the performance of the combined speed and current control scheme is compared with that of the standard vector control scheme
Resumo:
Through a grant received from the Australian Library and Information Association (ALIA), members of Health Libraries Australia (HLA) are collaborating with a researcher/educator to conduct a twelve month research project with the goal of developing an educational framework for the Australian health librarianship workforce of the future. The collaboration comprises the principal researcher and a representative group of practitioners from different sectors of the health industry who are affiliated with ALIA in various committees, advisory groups and roles. The research has two main aims: to determine the future skills requirements for the health librarian workforce in Australia; and to develop a structured, modular education framework for specialist post-graduate qualifications together with a structure for ongoing continuing professional development. The paper highlights some of the major trends in the health sector and some of the main environmental influences that may act as drivers for change for health librarianship as a profession, and particularly for educating the future workforce. The research methodology is outlined and the main results are described; the findings are discussed with regard to their implications for the development of a structured, competency-based education framework.
Resumo:
This paper provides a review of the state of the art relevant work on the use of public mobile data networks for aircraft telemetry and control proposes. Moreover, it describes the characterisation for airborne uses of the public mobile data communication systems known broadly as 3G. The motivation for this study was the explore how this mature public communication systems could be used for aviation purposes. An experimental system was fitted to a light aircraft to record communication latency, line speed, RF level, packet loss and cell tower identifier. Communications was established using internet protocols and connection was made to a local server. The aircraft was flown in both remote and populous areas at altitudes up to 8500 ft in a region located in South East Queensland, Australia. Results show that the average airborne RF levels are better than those on the ground by 21% and in the order of - 77dbm. Latencies were in the order of 500ms (1/2 the latency of Iridium), an average download speed of 0.48Mb/s, average uplink speed of 0.85Mb/s, a packet of information loss of 6.5%. The maximum communication range was also observed to be 70km from a single cell station. The paper also describes possible limitations and utility of using such communications architecture for both manned and unmanned aircraft systems.