919 resultados para Network-on-chip
Resumo:
We report on the first realtime ionospheric predictions network and its capabilities to ingest a global database and forecast F-layer characteristics and "in situ" electron densities along the track of an orbiting spacecraft. A global network of ionosonde stations reported around-the-clock observations of F-region heights and densities, and an on-line library of models provided forecasting capabilities. Each model was tested against the incoming data; relative accuracies were intercompared to determine the best overall fit to the prevailing conditions; and the best-fit model was used to predict ionospheric conditions on an orbit-to-orbit basis for the 12-hour period following a twice-daily model test and validation procedure. It was found that the best-fit model often provided averaged (i.e., climatologically-based) accuracies better than 5% in predicting the heights and critical frequencies of the F-region peaks in the latitudinal domain of the TSS-1R flight path. There was a sharp contrast however, in model-measurement comparisons involving predictions of actual, unaveraged, along-track densities at the 295 km orbital altitude of TSS-1R In this case, extrema in the first-principle models varied by as much as an order of magnitude in density predictions, and the best-fit models were found to disagree with the "in situ" observations of Ne by as much as 140%. The discrepancies are interpreted as a manifestation of difficulties in accurately and self-consistently modeling the external controls of solar and magnetospheric inputs and the spatial and temporal variabilities in electric fields, thermospheric winds, plasmaspheric fluxes, and chemistry.
Resumo:
The Helsinki Urban Boundary-Layer Atmosphere Network (UrBAN: http://urban.fmi.fi) is a dedicated research-grade observational network where the physical processes in the atmosphere above the city are studied. Helsinki UrBAN is the most poleward intensive urban research observation network in the world and thus will allow studying some unique features such as strong seasonality. The network's key purpose is for the understanding of the physical processes in the urban boundary layer and associated fluxes of heat, momentum, moisture, and other gases. A further purpose is to secure a research-grade database, which can be used internationally to validate and develop numerical models of air quality and weather prediction. Scintillometers, a scanning Doppler lidar, ceilometers, a sodar, eddy-covariance stations, and radiometers are used. This equipment is supplemented by auxiliary measurements, which were primarily set up for general weather and/or air-quality mandatory purposes, such as vertical soundings and the operational Doppler radar network. Examples are presented as a testimony to the potential of the network for urban studies, such as (i) evidence of a stable boundary layer possibly coupled to an urban surface, (ii) the comparison of scintillometer data with sonic anemometry above an urban surface, (iii) the application of scanning lidar over a city, and (iv) combination of sodar and lidar to give a fuller range of sampling heights for boundary layer profiling.
Resumo:
Results from two studies on longitudinal friendship networks are presented, exploring the impact of a gratitude intervention on positive and negative affect dynamics in a social network. The gratitude intervention had been previously shown to increase positive affect and decrease negative affect in an individual but dynamic group effects have not been considered. In the first study the intervention was administered to the whole network. In the second study two social networks are considered and in each only a subset of individuals, initially low/high in negative affect respectively received the intervention as `agents of change'. Data was analyzed using stochastic actor based modelling techniques to identify resulting network changes, impact on positive and negative affect and potential contagion of mood within the group. The first study found a group level increase in positive and a decrease in negative affect. Homophily was detected with regard to positive and negative affect but no evidence of contagion was found. The network itself became more volatile along with a fall in rate of change of negative affect. Centrality measures indicated that the best broadcasters were the individuals with the least negative affect levels at the beginning of the study. In the second study, the positive and negative affect levels for the whole group depended on the initial levels of negative affect of the intervention recipients. There was evidence of positive affect contagion in the group where intervention recipients had low initial level of negative affect and contagion in negative affect for the group where recipients had initially high level of negative affect.
Resumo:
In order to gain insights into events and issues that may cause errors and outages in parts of IP networks, intelligent methods that capture and express causal relationships online (in real-time) are needed. Whereas generalised rule induction has been explored for non-streaming data applications, its application and adaptation on streaming data is mostly undeveloped or based on periodic and ad-hoc training with batch algorithms. Some association rule mining approaches for streaming data do exist, however, they can only express binary causal relationships. This paper presents the ongoing work on Online Generalised Rule Induction (OGRI) in order to create expressive and adaptive rule sets real-time that can be applied to a broad range of applications, including network telemetry data streams.
Resumo:
This paper assesses the impact of the location and configuration of Battery Energy Storage Systems (BESS) on Low-Voltage (LV) feeders. BESS are now being deployed on LV networks by Distribution Network Operators (DNOs) as an alternative to conventional reinforcement (e.g. upgrading cables and transformers) in response to increased electricity demand from new technologies such as electric vehicles. By storing energy during periods of low demand and then releasing that energy at times of high demand, the peak demand of a given LV substation on the grid can be reduced therefore mitigating or at least delaying the need for replacement and upgrade. However, existing research into this application of BESS tends to evaluate the aggregated impact of such systems at the substation level and does not systematically consider the impact of the location and configuration of BESS on the voltage profiles, losses and utilisation within a given feeder. In this paper, four configurations of BESS are considered: single-phase, unlinked three-phase, linked three-phase without storage for phase-balancing only, and linked three-phase with storage. These four configurations are then assessed based on models of two real LV networks. In each case, the impact of the BESS is systematically evaluated at every node in the LV network using Matlab linked with OpenDSS. The location and configuration of a BESS is shown to be critical when seeking the best overall network impact or when considering specific impacts on voltage, losses, or utilisation separately. Furthermore, the paper also demonstrates that phase-balancing without energy storage can provide much of the gains on unbalanced networks compared to systems with energy storage.
Resumo:
In this paper we extend the results presented in (de Ponte, Mizrahi and Moussa 2007 Phys. Rev. A 76 032101) to treat quantitatively the effects of reservoirs at finite temperature in a bosonic dissipative network: a chain of coupled harmonic oscillators whatever its topology, i.e., whichever the way the oscillators are coupled together, the strength of their couplings and their natural frequencies. Starting with the case where distinct reservoirs are considered, each one coupled to a corresponding oscillator, we also analyze the case where a common reservoir is assigned to the whole network. Master equations are derived for both situations and both regimes of weak and strong coupling strengths between the network oscillators. Solutions of these master equations are presented through the normal ordered characteristic function. These solutions are shown to be significantly involved when temperature effects are considered, making difficult the analysis of collective decoherence and dispersion in dissipative bosonic networks. To circumvent these difficulties, we turn to the Wigner distribution function which enables us to present a technique to estimate the decoherence time of network states. Our technique proceeds by computing separately the effects of dispersion and the attenuation of the interference terms of the Wigner function. A detailed analysis of the dispersion mechanism is also presented through the evolution of the Wigner function. The interesting collective dispersion effects are discussed and applied to the analysis of decoherence of a class of network states. Finally, the entropy and the entanglement of a pure bipartite system are discussed.
Resumo:
The work presented here demonstrates the feasibility of using the single-mode fibers of an optical Internet network to deliver visible light between separate laboratories as a way to perform remote spectroscopy in the visible for teaching purposes. The coupling of a broadband light source into the single-mode fiber (SMF) and the characterization of optical losses as a function of the wavelength are discussed. Sample spectra were measured with a portable spectrometer controlled by an acquisition program developed with the LabVIEW software that allows the data to be collected and analyzed.
Resumo:
Purpose – This research focuses on finding the reasons, why members from different sectors join a cross-sector/multi-stakeholder CSR network and what motivates them to share (or not to share) their knowledge of CSR and their best practices. Design/methodology/approach – Semi-structured interviews were conducted with members of the largest cross-sector CSR network in Sweden. The sample base of 15 people was chosen to be able to represent a wider variety of members from each participating sectors. As well as the CEO of the intermediary organization was interviewed. The interviews were conducted via email and telephone. Findings – The findings include several reasons linked to the business case of CSR such as stakeholder pressure, competitive advantage, legitimacy and reputation as well as new reasons like the importance of CSR, and the access of further knowledge in the field. Further reasons are in line with members wanting to join a network, such as access to contact or having personal contacts. As to why members are sharing their CSR knowledge, the findings indicate to inspire others, to show CSR commitment, to be visible, it leads to business opportunity and the access of others knowledge, and because it was requested. Reasons for not sharing their knowledge would be the lack of opportunity, lack of time and the lack of experience to do so. Originality/value – The research contributes to existing studies, which focused on Corporate Social Responsibility and cross-sector networking as well as to inter-organizational knowledge sharing in the field of CSR.
Resumo:
O presente trabalho explora as causas pelas quais o campo da moda plus size carece de legitimidade com as consumidoras plus size. Eu explorei o assunto em três artigos. No primeiro, eu estudo o processo de legitimação de um novo mercado emergente, o mercado da moda plus size brasileira e os desafios para sua a institucionalização. Eu conduzi dezessete entrevistas com consumidoras plus size, uma netnografia em quatro blogs de moda plus size brasileiros e analisei de maneira semiótica um site que vende roupas de moda plus size. Meus resultados indicam que, apesar de ter atores legítimos que promovem essas marcas de moda plus size, o campo da moda plus size ainda é percebido como uma versão vergonhosa do campo da moda. Defendo aqui que o fato de uma das lógicas de campo da moda plus size ser estigma, acaba afetando os projetos identitários das consumidoras de maneira depreciativa, de forma elas não se envolvem em práticas de capital cultural que ocorrem dentro do campo da moda plus size. No segundo artigo, eu conduzi uma introspecção genealógica em que eu pesquisei questões de identidade. Como uma mulher (que se assume ) plus size, eu imaginei que seria relevante para olhar para dentro de mim mesma, a fim de explorar a forma como a minha identidade liga-se com a rede semiótica-material que me rodeia em termos de moda, alimentos e outros elementos. Meus dados vieram tanto de técnicas de introspecção simultâneas, quanto retrospectivas. Em termos teóricos, eu usei a ideia de ―assemblages‖ e eu foquei minha análise tanto nos aspectos materiais da minha rede de consumo, quanto na estabilidade da rede. As consequências da minha assemblage estão ligadas a uma gestão de qualidade total da minha identidade, tanto online como off-line, refletidas em práticas de consumo que se conectam à ideia de uma lógica de consumo bulímica em que o consumo de alimentos e gestão corpo estão interligadas. Por fim, no meu terceiro artigo, eu explorei o conceito de identidade a partir do consumo da moda feminina plus size. Foram feitas catorze entrevistas fenomenológicas, cujos dados foram analisados a partir de uma perspectiva hermenêutica. Três categorias temáticas emergiram da análise de dados: a construção da identidade por meio da moda, elementos de identidade plus size e estratégias criativas para lidar com a falta de produtos para mulheres plus size no varejo. Entre os principais resultados, destacam-se a forma como o termo plus size atua como estigma, influenciando projetos de identidade das consumidoras, o papel do varejo no processo de estigmatização e a saga épica de compras, que envolve um "mercado negro", com a participação de vendedores. Eu concluo discutindo o papel da identidade na instabilidade do campo da moda plus size.
5th BRICS Trade and Economic Research Network (TERN) meeting: the impact of mega agreements on BRICS
Resumo:
The BRICS TERN – BRICS Trade and Economics Research Network is a group of independent research institutes established four years ago by five think tanks from Brazil, Russia, India, China and South Africa. The main objective of the network is to study different aspects of trade and economic relations amongst these five countries. The purpose of the V BRICS TERN Meeting was to analyze and debate the effects of the negotiations of the Mega Agreements, mainly those initiated by the US and the EU, already in negotiation, to each of the BRICS Trade Policies. Both Mega Agreements were examined – the Trans Pacific Partnership (TPP) and the Transatlantic Trade and Investment Partnership (TTIP). The studies included the main impacts on trade flows and on the international trade rules system, respecting the perspective of each of the countries concerned. This workshop was an initiative of the Center for Global Trade and Investments (CGTI), a think-tank on International Trade held by FGV Sao Paulo School of Economics. Its main objective is the research on trade regulation, preferential trade agreements, trade and currency, trade and global value chains, through legal analysis and economic modelling. One of its main researches, now, is on the potential economic and legal impacts of the Mega Agreements on Brazil and WTO rules. This meeting was organized in March14, 2014, in Rio de Janeiro, in a perfect timing for introducing such issues in the international agenda, in advance of the 6th BRICS Summit scheduled to be held in Brazil in July 2014.
Resumo:
This paper describes a method of identifying morphological attributes that classify wear particles in relation to the wear process from which they originate and permit the automatic identification without human expertise. The method is based on the use of Multi Layer Perceptron (MLP) for analysis of specific types of microscopic wear particles. The classification of the wear particles was performed according to their morphological attributes of size and aspect ratio, among others. (C) 2010 Journal of Mechanical Engineering. All rights reserved.
Resumo:
This work presents a methodology to analyze electric power systems transient stability for first swing using a neural network based on adaptive resonance theory (ART) architecture, called Euclidean ARTMAP neural network. The ART architectures present plasticity and stability characteristics, which are very important for the training and to execute the analysis in a fast way. The Euclidean ARTMAP version provides more accurate and faster solutions, when compared to the fuzzy ARTMAP configuration. Three steps are necessary for the network working, training, analysis and continuous training. The training step requires much effort (processing) while the analysis is effectuated almost without computational effort. The proposed network allows approaching several topologies of the electric system at the same time; therefore it is an alternative for real time transient stability of electric power systems. To illustrate the proposed neural network an application is presented for a multi-machine electric power systems composed of 10 synchronous machines, 45 buses and 73 transmission lines. (C) 2010 Elsevier B.V. All rights reserved.