920 resultados para NETWORK MODELS
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Dissertação para obtenção do Grau de Mestre em Matemática e Aplicações Especialização em Actuariado, Estatística e Investigação Operacional
Critical Velocity obtained using Simplified Models of the Railway Track: Viability and Applicability
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Increased demands on the capacity of the railway network gave rise to new issues related to the dynamic response of railway tracks subjected to moving vehicles. Thus, it becomes important to evaluate the applicability of traditionally used simplified models which have a closed form solution. Regarding simplified models, transversal vibrations of a beam on a visco-elastic foundation subjected to a moving load are considered. Governing equations are obtained by Hamilton’s principle. Shear distortion, rotary inertia and effect of axial force are accounted for. The load is introduced as a time varying force moving at a constant velocity. Transversal vibrations induced by the load are solved by the normal-mode analysis. Reflected waves at the extremities of the full beam are avoided by introduction of semi-infinite elements. Firstly, the critical velocity obtained from this model is compared with results of an undamped Euler- Bernoulli formulation with zero axial force. Secondly, a finite element model in ABAQUS is examined. The new contribution lies in the introduction of semi- infinite elements and in the first step to a systematic comparison, which have not been published so fa
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On a mobile ad-hoc network environment, where the resources are scarce, the knowledge about the network's link state is essential to optimize the routing procedures. This paper presents a study about different pheromone evaluation models and how they react to possible changes in traffic rate. Observing how the pheromone value on a link changes, it could be possible to identify certain patterns which can indicate the path status. For this study, the behavior of the Ant System evaluation model was compared with a Temporal Active Pheromone model (a biological approach) and a Progressive Pheromone Reduction model with and without a maximum pheromone limit.
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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.
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Dissertação para obtenção do Grau de Mestre em Engenharia Informática
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PhD Thesis in Bioengineering
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Delayed perfect monitoring in an infinitely repeated discounted game is modelled by letting the players form a connected and undirected network. Players observe their immediate neighbors' behavior only, but communicate over time the repeated game's history truthfully throughout the network. The Folk Theorem extends to this setup, although for a range of discount factors strictly below 1, the set of sequential equilibria and the corresponding payoff set may be reduced. A general class of games is analyzed without imposing restrictions on the dimensionality of the payoff space. This and the bilateral communication structure allow for limited results under strategic communication only. As a by-product this model produces a network result; namely, the level of cooperation in this setup depends on the network's diameter, and not on its clustering coefficient as in other models.
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Functional connectivity in human brain can be represented as a network using electroencephalography (EEG) signals. These networks--whose nodes can vary from tens to hundreds--are characterized by neurobiologically meaningful graph theory metrics. This study investigates the degree to which various graph metrics depend upon the network size. To this end, EEGs from 32 normal subjects were recorded and functional networks of three different sizes were extracted. A state-space based method was used to calculate cross-correlation matrices between different brain regions. These correlation matrices were used to construct binary adjacency connectomes, which were assessed with regards to a number of graph metrics such as clustering coefficient, modularity, efficiency, economic efficiency, and assortativity. We showed that the estimates of these metrics significantly differ depending on the network size. Larger networks had higher efficiency, higher assortativity and lower modularity compared to those with smaller size and the same density. These findings indicate that the network size should be considered in any comparison of networks across studies.
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The ability to model biodiversity patterns is of prime importance in this era of severe environmental crisis. Species assemblage along environmental gradient is subject to the interplay of biotic interactions in complement to abiotic environmental filtering. Accounting for complex biotic interactions for a wide array of species remains so far challenging. Here, we propose to use food web models that can infer the potential interaction links between species as a constraint in species distribution models. Using a plant-herbivore (butterfly) interaction dataset, we demonstrate that this combined approach is able to improve both species distribution and community forecasts. Most importantly, this combined approach is very useful in rendering models of more generalist species that have multiple potential interaction links, where gap in the literature may be recurrent. Our combined approach points a promising direction forward to model the spatial variation of entire species interaction networks. Our work has implications for studies of range shifting species and invasive species biology where it may be unknown how a given biota might interact with a potential invader or in future climate.
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We survey the main theoretical aspects of models for Mobile Ad Hoc Networks (MANETs). We present theoretical characterizations of mobile network structural properties, different dynamic graph models of MANETs, and finally we give detailed summaries of a few selected articles. In particular, we focus on articles dealing with connectivity of mobile networks, and on articles which show that mobility can be used to propagate information between nodes of the network while at the same time maintaining small transmission distances, and thus saving energy.
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Nonlinear Noisy Leaky Integrate and Fire (NNLIF) models for neurons networks can be written as Fokker-Planck-Kolmogorov equations on the probability density of neurons, the main parameters in the model being the connectivity of the network and the noise. We analyse several aspects of the NNLIF model: the number of steady states, a priori estimates, blow-up issues and convergence toward equilibrium in the linear case. In particular, for excitatory networks, blow-up always occurs for initial data concentrated close to the firing potential. These results show how critical is the balance between noise and excitatory/inhibitory interactions to the connectivity parameter.
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Aim: The study aims to describe the activities of the Swiss Early Psychosis Project (SWEPP) which was founded in 1999 as a national network to further and disseminate knowledge on early psychosis (EP) and to enhance collaboration between healthcare groups. Methods: The present paper is a detailed account of the initiation and the development of the Swiss network. We describe all activities such as the several educational campaigns that were addressed to primary and secondary care groups since the early days. We also provide an overview of the current status of EP services throughout the country. Results: Today, most regions in Switzerland provide specialized EP inpatient and/or outpatient services with a clinical or combined clinical research approach that targets at-risk and/or first-episode populations. Some more recently initiated EP services have been launched as collaborative models between several local or regional psychiatric services. Conclusions: The increasing number of EP services and experts in Switzerland may mirror the catalyzing contribution of the Swiss Early Psychosis Project in this important field of health care. The country's small size and the increasing density of specialized services provide excellent bases for larger-scale networking activities in the future, both in clinical and research areas.
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In the recent years most libraries have focused on mass digitization programs and keeping electronic born documents, showing and organizing them in a repository. While those repositories have evolved to a much more manageable systems focusing on the user expectations and introducing web 2.0 tools, digital preservation is still in the to-do list of most of them. There is quite a lot of studies focused on preservation and some complex models exist, unfortunately, very few practical systems are running and its quite difficult for a library to get involved in a solution already tested by others. The CBUC (Consortium of University Catalan Libraries) runs TDX, an ETD repository now keeping more than 10.000 full text thesis from any of the 12 university members. After 10 years running TDX a solid preservation system was needed to ensure every thesis would be kept as it was regardless what happens to the repository. The perfect solution was found in the MetaArchive cooperative, this is the effort of many insitutions to keep a copy of each other content through a newtwork using the LOCKSS software as a mechanism to keep track of any change. The presentation will shortly introduce what TDX and MetaArchive is but will, in a practical way, show how the LOCKSS network for presrervation works. Finally a summary of the benefits of the overall experience will be shown.
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NICaN Regional Supportive & Palliative Care Network Friday 30th May 2008 Lecture Theatre, Fern House Antrim 2.00 pm - 5.00 pm Welcome, Introductions Stuart MacDonnell, Chair of the Supportive and Palliative Care network welcomed everyone to the meeting. This meeting had been rescheduled to accommodate the validation workshop for the regional palliative care model, which took place on Friday,18th April. Acknowledging the full agenda, several items were pulled forward to accommodate speakers SPC_0809_03 Modernisation and Reform of Supportive and Palliative care Mr MacDonnell welcomed Dr Sonja McIlfatrick and Dr Donna Fitzimons, members of the Phase 1 Project Team for the Modernisation and Reform of palliative care. Their presentation highlighted the journey taken by the Project Team since January 2008 - May 2008. Seeking to deliver the network vision, for any person with palliative care need, cancer or non - cancer, the project team incorporated several methodologies. The literature review identified best practice. An assessment of need including epidemiological data and review of service provision. Consultation reflected the engagement with patients, carers and professional forums, primary care and non-malignant focus groups. The breadth of consultation confirmed the evidence for the identified components of the model. These were validated at the April workshop. External review of the work was provided by Dr Phil Larkin (Galway Uni) Prof David Clark (End of Life Care Observatory, Lancaster University) and Mr Bob Neillans (Chair of the Mid Trent Palliative care network, which has been involved in the Delivering choice programme within Lincolnshire). The Guiding Principles of the model reinforced Patient and family centred care, enhanced community provision and supported by specialists. The components of the model are · Identification of patient with Palliative careened · Holistic Assessment · Integration of services · Coordination of care · End of Life Care and Bereavement Care The consultation process also highlighted the need for Increased Public and Professional Awareness. This was recognised as an encompassing component. Underpinning the model is the need for robust Education and common core values e.g. dignity, choice, advocacy, empowerment, partnership working. Stuart MacDonnell, who also chaired the steering group during the project, congratulated the Project Team for delivering the comprehensive document on schedule. The Report has been submitted to the NICaN Board and the DHSSPSNI. In addition, an outline for Phase 2 of this work has been submitted. Mr MacDonnell recognised that there is real opportunity for palliative care to benefit from the DHSSPSNI commitment to concrete developments. Phase 2 will progress the current high-level components of the model into quality services developments at a local level, demonstrating integration throughout. The methods propose continued engagement with the Delivering Choice Programme enabled through a Central and also Local Teams. The report and the Appendices care available on the NICaN website www.nican@n-i.nhs.uk SPC_0809_01 Chairman's Business · Update on the Cancer Service Framework, the document has been submitted and presented to the Departmental Programme Board. Next stages will include the review of costs and development of a implementation guidance It is hoped that the completed document should be available for public consultation in Autumn 2008. with a launch of the framework document and accompanying implementation guide in Spring 2009. Some funding has already been identified to advance key areas of work including, Advanced communication skills training, peer review and an appointment of a post to develop the cancerni.net, focusing on children and e-learning tools. · Children's and Adolescent Cancer network group , Liz Henderson is to convene a group to consider how this is to be taken forward. · NICaN appointments Recognition was given to the significant contribution made by Dr Gerard Daly during his position as NICaN Lead Clinician, particularly throughout the early establishment of the NICaN. Dr Dermott Hughes (Western Trust) has been appointed as the NICaN Medical Director. The Primary Care Director post has been advertised and it is hoped that the Director of Network will be advertised later in Summer. Endorsement of End of Life care paper. The Paper was presented and endorsed at the March 2008 NICaN Board meeting. Mr David Galloway (Director of Secondary Care) emphasised the need for this important work to be recognised within the regional model to ensure that it is reflected in future models of service delivery Congratulations were again echoed to the Chair of the End of Life Group for this work, Dr Glynis Henry, and the working group Other recognition Mr MacDonnell congratulated the significant achievements across the network. These include: · Dr Francis Robinson (Consultant Palliative Medicine, Western Trust) Awarded - Consultant of the year at the NI Health Care awards. · Mrs Evelyn Whittaker Hospice Nurse Specialist, NI Hospice, Joint Second Prize in the Development award within the International Journal of Palliative Nursing Awards, for her work in development of palliative care education in nursing homes. · Mr Ray Elder is the newly appointed Team Leader of Community Palliative care, SE Trust. · Mrs Bridget Denvir, who managed the establishment of one of the first community multiprofessional palliative care teams is moving to work with establishing integrated teams within the Belfast Trust. Bridget has been an active core member of the network and here contribution has been much appreciated. Mrs Sharon Barr will attend in future. SPC_0809_02 Minutes & matters Arising from Meeting, 13th December 2007 No amendments were made to the draft minutes from the December meeting. These will be posted on the NICaN website for future reference. Palliative Care Research Following consultation, the response to the business case for the All Ireland Institute was forwarded on 22 February 2008 to Prof David Clark. Prof Judith Hill informed the group that terms of tender are now being developed. Awareness raising across academic institutions continues to engage interest in potential partnerships. Atlantic Philantrophies have offered financial support to the venture and match funding is being sought from across jurisdictions. Previous discussions at Network meetings have endorsed the need to establish a work strand for research and development within palliative and end of life care. To identify the body of interested parties and explore the strengths and weaknesses of a collaborative model for research, a workshop, - Building collaboration for Palliative and End of life Care Research -will take place on 4 June 10am - 2pm.in the Comfort Hotel.Antrim, The workshop will be chaired by Prof David Clark, Director of the International Observatory on End of Life Care. Prof Shelia Payne, Help the Hospices Chair in Hospice Studies and co director of the Cancer Experiences Collaborative will present the Experiences and Results from Research Collaborative. Feedback from this event will be brought back to the next meeting in September. SPC_0809_04 Patient Information pathways - a pathway for advanced disease Ms Danny Sinclair, NICaN Regional Coordinator for Patient Information informed the network of how patient information pathways have been developed in line with the Cancer Services Collaborative. Emerging themes, with regard to information needs of patients with advanced disease, are being identified from the work undertaken across the tumour groups. It is important to identify all information needs to develop a generic pathway of information resources for advanced disease to be endorsed by the Supportive and Palliative care network. This could be used across the all tumour specific information pathways and across organisational boundaries. The resulting pathway could potentially be used for non- cancer condition. A group is to be established to take this work forward. The group will: · Develop a list of advanced disease information themes · .Identify when they become relevant for the patient or their carer · .Identify existing resources · .Develop resources where needed · .Participate or nominate when review is required Dr Sheila Kelly nominated Helen Hume (SETrust) Paula Kealey will also contribute to this work; a nomination from the Patient and Public Information Forum has also been identified. A date will be circulated across the network to engage further interest and establish group SPC_0809_08 Development of a Regional Syringe Driver Prescription Chart Ms Kathy Stephenson reported that the second consultation of the draft regional syringe driver prescription chart and the focus group discussions, Pilots of the chart are to be undertaken within Trust, Hospices and General Practices. SPC_0809_05 A framework for Generalist and Specialist Palliative and End of Life Care Competency Dr Kathleen Dunne, lead of the Education works strand, reported on the findings following consultation of the Education framework. The report was widely appreciated across the network and valued as a significant and timely document for the commissioning of generalist and specialist adult palliative care education. Mr MacDonnell congratulated Dr Dunne and the members of the education workstrand for developing the framework aligning its significance to the underpinning needs of the regional model Amendments will be made to the document and then forwarded to the NICaN Board for endorsement. A process of implementation will be explored and reported to the network group at the September meeting. Key target areas for generalist palliative care education were highlighted within care of the elderly and general medicine. . SPC_0809_06 Pallcareni.net-a website for people with palliative care needs Ms Danny Sinclair, reminded the group of the pending amalgamation of the CAPriCORN and NICaN website. The resulting new web address will be www. cancerni.net. Recurrent funding has been secured to ensure the development of the supportive and palliative care website.www.Pallcareni.net The new website will host good information for people with palliative care needs, regardless of diagnosis. It will be accessible via the cancerni.net portal or independently as the pallcareni portal. It will signpost people with palliative care needs to condition- specific websites. The website will also enable the communication needs of the NI Regional Supportive & Palliative Care Network. This is a very significant method of seeking to enable greater understanding of palliative care for public and professionals, as highlighted within the regional model. Currently the material from the CAPriCORN website is being migrated onto cancerni and /or pallcareni.net as appropriate. To enable the further development of this opportunity a steering group of interested individuals is to be established. Their role will be to: · Drive the development of the website so it meets the needs of public and professionals through the sourcing and development of additional content · Identify any support that is needed, e.g. technical support · Review the website as a whole as it grows (coordinating condition-specific developments) · Review the functions of the website to aid communication throughout the Supportive and Palliative care network The steering group representation should reflect the constituencies within the Supportive and Palliative Care network. Current expressions of interest have come from Heather Reid and Valerie Peacock. A date will be circulated across the network to engage further interest and establish group SPC_0809_07 Update of Guidelines workstrand Dr Pauline Wilkinson presented the current work within the guidelines workstrand. 1. Brief Holistic Assessment & Referral Criteria to Specialist Palliative Care The development of an Holistic assessment Tool will help to identify holistic need at generalist and specialist level. Recognition of complex need prompts appropriate referral to specialist palliative care. The regional referral form is compatible with the Minimum Data set. The final drafts of this work are to be circulated widely, inclusive of service framework groups, primary care, secondary care and the supportive and palliative care network. Consultation will take place during June and July. Piloting of the forms will also be undertaken. 2. Control of Pain in Cancer Patients The original guidelines where developed 2003 and are now ready for review. The Mapping exercise, undertaken in May 2007, highlighted that the Guidelines were poorly adopted. The group have reviewed the pending SIGN 2 guidelines for pain with regard to practice in Northern Ireland. These are highly evidence based and are due to be launched this Summer. Whilst an excellent resource their comprehensiveness limits their readability, this may result in poor compliance. The Guidelines group feel it is important to have accessible and user-friendly guidelines particularly for Generalists and Out of hours. There are examples of good work that has taken place across the province, but there is a need for regional consistency. Dr Wilkinson has contacted Dr Carolyn Harper (Deputy CMO) and GAIN with regard to enabling funding to progress this work. The Guidelines group hope to approach the NICaN Primary Care Group to work in collaboratively on this piece, based on the templates already available. The works should be available in both electronic and paper versions. 3. Care of the dying & Breaking bad news Dr Gail Johnston has now completed an Audit of the Care of the Dying Pathways within the EHSSB. Gail is also seeking to examine to what extent the Regional Guidelines for Breaking Bad News are being implemented in the EHSSB with a view to identifying the need for further training or organisational structures that would facilitate future uptake. 4. Advances in new Technology Syringe Drivers Dr Wilkinson reported on a presentation made to the guidelines group by Mr Jim Elliot, Principle Engineer, Cardiology & Ann McLean, and Macmillan Palliative Care Nurse RVH. There is increasing concern with regard to how devices meet the recommended safety standards and how to reduce error. New devices have 3 point checking, automatic detection of syringe, automatic flow rates, full range of alarms, battery status and data download to provide an event log. There are now 2 companies in UK who have devices that meet these safety criteria. The current Graseby syringe drivers, which have been on the market and used predominately within Northern Ireland over the past 27 years Most new devices are not compatible with the regionally available monoject syringe, however contractual changes will lead to the withdrawal of the monoject syringes in October 2008. The Guidelines group supports a regional approach to this matter. This was echoed in the Supportive and Palliative care network. An option appraisal, identifying costs, and training issues should be developed through the engagement with Trusts and DHSSPSNI. The issue of Patient safety should be raised with the DHSSPSNI. SPC_0809_09 Evaluation of Supportive and Palliative Care network Deferred to next meeting. . SPC_0809_10 Emerging Issues Mrs Anne Coyle, Bereavement Coordinator, Southern Trust, announced that the Regional Bereavement Strategy is soon to be released. Anne supported the close alignment between the content of the strategy and the work of the regional model and other workstrands within the Supportive and Palliative care network. Ms Eleanor Donaghy, Transplant Coordinator, briefly highlighted the issue of tissue donation. Each year Northern Ireland has a dearth of corneal donations. There is no upper age limit for donation and retrieval is not limited by a cancer diagnosis. Recipients do not require immunosuppressive and the transplant is lifelong. The National Blood Service provided coordination of this donation they may be contacted via 07659180773. It is hoped that Mrs Coyle and Ms Donaghy could provide more comprehensive presentations at a future meeting. Events · Irish Psycho- Oncology Group Seminar, Cork 6 June, Exploring the Struggle for meaning in Cancer · Integrated Care: Putting Research into Practice, 13June, Trinity College, Dublin · Macmillan online conference Friday 13 June 2008, 9am - 5pm · Delivering effective end of life care: developing partnership working 15 Oct 2008, 9.30 -4.15 pm London Network Meeting was closed at 5.00pm SPC_0607_ Dates of Future Meetings (please note the change of venue) 10th September 2008, 1.30 - 5pm venue to be decided15th January 2009, 1.30 - 5pm venue to be decided12th May 2009, 1.30 - 5pm venue to be decided Attendances Apologies Stuart MacDonnellLorna NevinSonja McIlfatrick Donna FitzsimonsKathleen DunnePauline WilkinsonKathy StephensonSheila KellyMarie Nugent,Anne CoyleFiona GilmourJudith HillLorna DicksonMargaret CarlinLoretta GribbenYvonne Duff Lesley NelsonLiz HendersonSue FosterCathy PayneGraeme PaynePatricia MageeGeraldine WeatherupPaula KealyCaroline McAfeeLinda WrayValerie PeacockAnn McCleanRay Elder Martin BradleyHelen HumeGillian RankinHeather MonteverdeJulie DoyleAlison PorterYvonne SmythLiz Atkinson,Glynis HenryMaeve HullyCaroline HughesAnn FinnBob BrownSharon BarrJulie DoyleJanis McCulla .
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Our purpose in this article is to define a network structure which is based on two egos instead of the egocentered (one ego) or the complete network (n egos). We describe the characteristics and properties for this kind of network which we call “nosduocentered network”, comparing it with complete and egocentered networks. The key point for this kind of network is that relations exist between the two main egos and all alters, but relations among others are not observed. After that, we use new social network measures adapted to the nosduocentered network, some of which are based on measures for complete networks such as degree, betweenness, closeness centrality or density, while some others are tailormade for nosduocentered networks. We specify three regression models to predict research performance of PhD students based on these social network measures for different networks such as advice, collaboration, emotional support and trust. Data used are from Slovenian PhD students and their s