| 51. |
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| 52. |
- Krzywda, Jakub, et al.
(författare)
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Telco Clouds: Modelling and Simulation
- 2015
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Ingår i: Proceedings of the 5th International Conference on Cloud Computing and Services Science. - : SciTePress. - 9789897581045 ; , s. 597-609
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Konferensbidrag (refereegranskat)abstract
- In this paper, we propose a telco cloud meta-model that can be used to simulate different infrastructure con- figurations and explore their consequences on the system performance and costs. To achieve this, we analyse current telecommunication and data centre infrastructure paradigms, describe the architecture of the telco cloud and detail the benefits of merging both infrastructures in a unified system. Next, we detail the dynamics of the telco cloud and identify the components that are the most relevant from the perspective of modelling performance and cost. A number of well established simulation technologies exist for most of the telco cloud components, we thus proceed with surveying existing models in an attempt to construct a suitable composite meta-model. Finally, we present a showcase scenario to demonstrate the scope of our telco cloud simulator.
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| 53. |
- Le Duc, Thang, 1980-, et al.
(författare)
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Application, Workload, and Infrastructure Models for Virtualized Content Delivery Networks Deployed in Edge Computing Environments
- 2018
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Ingår i: 2018 27th International Conference on Computer Communication and Networks (ICCCN). - : IEEE. - 9781538651568 - 9781538651575
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Konferensbidrag (refereegranskat)abstract
- Content Delivery Networks (CDNs) are handling a large part of the traffic over the Internet and are of growing importance for management and operation of coming generations of data intensive applications. This paper addresses modeling and scaling of content-oriented applications, and presents workload, application, and infrastructure models developed in collaboration with a large-scale CDN operating infrastructure provider aimed to improve the performance of content delivery subsystems deployed in wide area networks. It has been shown that leveraging edge resources for the deployment of caches of content greatly benefits CDNs. Therefore, the models are described from an edge computing perspective and intended to be integrated in network topology aware application orchestration and resource management systems.
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| 54. |
- Le Duc, Thang, 1980-, et al.
(författare)
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Machine Learning Methods for Reliable Resource Provisioning in Edge-Cloud Computing : A Survey
- 2019
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Ingår i: ACM Computing Surveys. - : Association for Computing Machinery (ACM). - 0360-0300 .- 1557-7341. ; 52:5
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Tidskriftsartikel (refereegranskat)abstract
- Large-scale software systems are currently designed as distributed entities and deployed in cloud data centers. To overcome the limitations inherent to this type of deployment, applications are increasingly being supplemented with components instantiated closer to the edges of networks—a paradigm known as edge computing. The problem of how to efficiently orchestrate combined edge-cloud applications is, however, incompletely understood, and a wide range of techniques for resource and application management are currently in use.This article investigates the problem of reliable resource provisioning in joint edge-cloud environments, and surveys technologies, mechanisms, and methods that can be used to improve the reliability of distributed applications in diverse and heterogeneous network environments. Due to the complexity of the problem, special emphasis is placed on solutions to the characterization, management, and control of complex distributed applications using machine learning approaches. The survey is structured around a decomposition of the reliable resource provisioning problem into three categories of techniques: workload characterization and prediction, component placement and system consolidation, and application elasticity and remediation. Survey results are presented along with a problem-oriented discussion of the state-of-the-art. A summary of identified challenges and an outline of future research directions are presented to conclude the article.
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| 55. |
- Le Duc, Thang, 1980-, et al.
(författare)
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Workload Diffusion Modeling for Distributed Applications in Fog/Edge Computing Environments
- 2020
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Ingår i: ICPE '20. - New York : Association for Computing Machinery (ACM). - 9781450369916 ; , s. 218-229
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Konferensbidrag (refereegranskat)abstract
- This paper addresses the problem of workload generation for distributed applications in fog/edge computing. Unlike most existing work that tends to generate workload data for individual network nodes using historical data from the targeted node, this work aims to extrapolate supplementary workloads for entire application / infrastructure graphs through diffusion of measurements from limited subsets of nodes. A framework for workload generation is proposed, which defines five diffusion algorithms that use different techniques for data extrapolation and generation. Each algorithm takes into account different constraints and assumptions when executing its diffusion task, and individual algorithms are applicable for modeling different types of applications and infrastructure networks. Experiments are performed to demonstrate the approach and evaluate the performance of the algorithms under realistic workload settings, and results are validated using statistical techniques.
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| 56. |
- Leznik, Mark, et al.
(författare)
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Multivariate Time Series Synthesis Using Generative Adversarial Networks
- 2021
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Ingår i: ICPE 2021. - New York, NY, USA : Association for Computing Machinery, Inc. - 9781450381949 ; , s. 43-50
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Konferensbidrag (refereegranskat)abstract
- Collection and analysis of distributed (cloud) computing workloads allows for a deeper understanding of user and system behavior and is necessary for efficient operation of infrastructures and applications. The availability of such workload data is however often limited as most cloud infrastructures are commercially operated and monitoring data is considered proprietary or falls under GPDR regulations. This work investigates the generation of synthetic workloads using Generative Adversarial Networks and addresses a current need for more data and better tools for workload generation. Resource utilization measurements such as the utilization rates of Content Delivery Network (CDN) caches are generated and a comparative evaluation pipeline using descriptive statistics and time-series analysis is developed to assess the statistical similarity of generated and measured workloads. We use CDN data open sourced by us in a data generation pipeline as well as back-end ISP workload data to demonstrate the multivariate synthesis capability of our approach. The work contributes a generation method for multivariate time series workload generation that can provide arbitrary amounts of statistically similar data sets based on small subsets of real data. The presented technique shows promising results, in particular for heterogeneous workloads not too irregular in temporal behavior.
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| 57. |
- Lind, Mikael, et al.
(författare)
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Acting Out the Swedish e-Government Action Plan : mind and mend the gap
- 2009
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Ingår i: International Journal of Public Information Systems. - : Mittuniversitetet. - 1653-4360. ; 5:2, s. 37-60
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Tidskriftsartikel (refereegranskat)abstract
- The Swedish Government has made the decision to reclaim its world leadership in the eGov ranking circus within two years. This is indeed easier said than done; policy documents alone will not overcome the age old gaps between the three layers of public administration containing some six hundred independently managed agencies. At best, it may prove possible to make the agencies in the state sector capability cloud march to the whole_of_government tune. Included in the problems faced in the attempted paradigm shift are (i) unrealistic time scale, (ii) governance is not possible without an enterprise architecture, (iii) the modeling of the needs of the end user cannot be left solely to individual agencies, (iv) clusters and federations must be defined by means of federation level agreements in addition to service level agreements, (v) low adherence level to EU’s directives regarding e.g. Services and Public Information Re-usage will be rewarded with low eGov EU ranking, and (vi) there are very few mandatory standards and profiles for Swedish agencies and no Swedish National Interoperability Framework on the horizon. Among the positive signs are that very ambitious work is taking place in both the defense and e-health sectors. To compensate for the unrealistic time scale, and to secure public value, it is an absolute must for forums with reference to eGov discussions, architecting work and information exchange to be established as soon as possible.
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| 58. |
- Lindberg, Olof, et al.
(författare)
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Cortical morphometric subclassification of frontotemporal lobar degeneration
- 2009
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Ingår i: American Journal of Neuroradiology. - 0195-6108 .- 1936-959X. ; 30:6, s. 1233-1239
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Frontotemporal lobar degeneration (FTLD) is a primary neurodegenerative disease comprising 3 clinical subtypes: frontotemporal dementia (FTD), semantic dementia (SD), and progressive nonfluent aphasia (PNFA). The subdivision is primarily based on the characteristic clinical symptoms displayed by each subtype. We hypothesized that these symptoms would be correlated to characteristic patterns of brain atrophy, which could be indentified and used for subclassification of subjects with FTLD. MATERIALS AND METHODS: Volumes of 9 cortical regions were manually parcellated and measured on both hemispheres on 27 controls, 12 patients with FTD, 9 patients with PNFA, and 13 patients with SD. The volumetric data were analyzed by traditional t tests and by a multivariate discriminant analysis (partial least squares discriminant analysis). RESULTS: The ensemble or pattern of atrophy was a good discriminator in pair-wise comparison between the subtypes: FTD compared with SD (sensitivity 100% [12/12], specificity 100% [13/13]); FTD compared with PNFA (sensitivity 92% [11/12], specificity 89% [8/9]); and SD compared with PNFA (sensitivity 86% [11/13], specificity 100% [9/9]). Temporal-versus-frontal atrophy was the most important pattern for discriminating SD from the other 2 subtypes. Right-sided versus left-sided atrophy was the most important pattern for discriminating between subjects with FTD and PNFA. CONCLUSIONS: FTLD subtypes generally display a characteristic pattern of atrophy, which may be considered in diagnosing patients with FTLD.
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| 59. |
- Lindberg, Olof, et al.
(författare)
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Hippocampal Shape Analysis in Alzheimer's Disease and Frontotemporal Lobar Degeneration Subtypes
- 2012
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Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 30:2, s. 355-365
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Tidskriftsartikel (refereegranskat)abstract
- Hippocampal pathology is central to Alzheimer's disease (AD) and other forms of dementia such as frontotemporal lobar degeneration (FTLD). Autopsy studies have shown that certain hippocampal subfields are more vulnerable than others to AD and FTLD pathology, in particular the subiculum and cornu ammonis 1 (CA1). We conducted shape analysis of hippocampi segmented from structural T1 MRI images on clinically diagnosed dementia patients and controls. The subjects included 19 AD and 35 FTLD patients [13 frontotemporal dementia (FTD), 13 semantic dementia (SD), and 9 progressive nonfluent aphasia (PNFA)] and 21 controls. Compared to controls, SD displayed severe atrophy of the whole left hippocampus. PNFA and FTD also displayed atrophy on the left side, restricted to the hippocampal head in FTD. Finally, AD displayed most atrophy in left hippocampal body with relative sparing of the hippocampal head. Consistent with neuropathological studies, most atrophic deformation was found in CA1 and subiculum areas in FTLD and AD.
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| 60. |
- Lohmander, Anette, et al.
(författare)
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Kommunikations- och sväljstörningar genom hela livet : ett logopediskt ståndpunktsdokument
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Den forskning som bedrivs inom logopedi i Sverige idag spänner över ett brett spektrum av medfödda, utvecklingsrelaterade och förvärvade kommunikationsstörningar på grund av röst-, tal- och språksvårigheter samt sväljstörningar. Precis som i andra länder pågår en snabb utveckling både mot en breddning av det urval av områden som det forskas kring och ett ökat fokus på nationellt samarbete. Även om de framsteg som görs inom respektive fält kan mätas genom de forskningsrapporter som publiceras av respektive forskargrupper, finns det ett behov av att granska vilka forskningsinsatser som bedrivs jämte det demografiska sammanhanget. I detta ståndpunktsdokument ger vi en översikt över logopediämnet och den forskning som bedrivs i Sverige. I en kubmodell illustreras hur kommunikations- och sväljstörningar kan beskrivas. Stratifierade (per åldersintervall) uppskattningar av prevalensen av kommunikations- och sväljstörningar ges baserat på 2016 års befolkningsstruktur. Genom att presentera dessa två komponenter identifieras forskningsområden och riktningar inom logopedi som behöver ges ökad uppmärksamhet i det kommande forskningsarbetet.
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