987 resultados para T-Engine
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Information Paper, No 26
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Three factors define the main difficulties faced by developing countries in the area of trade facilitation: (i) limited understanding and use by governments and business (especially SMEs) of trade facilitation and of ICT tools and techniques; (ii) developing countries' limited capacity for policy analysis and inadequate policy instruments for the implementation of trade facilitation, and (iii) inadequate policy coordination for negotiation on trade facilitation. These obstacles tend to reduce countries' development opportunities and to increase the costs of general economic development and social welfare.The United Nations, through its five regional commissions, is launching a project that seeks to disseminate the benefits of trade facilitation and the standards, tools and requirements for its successful implementation. The project will focus on trade facilitation promoted by: (a) enhanced knowledge and understanding of governments and business regarding trade facilitation and the role of ICT; (b) enhanced use of ICT by SMEs in trade facilitation, and (c) national capacity-building for trade facilitation negotiations.
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The increased fuel economy and driveability of modern internal combustion engine vehicles (ICEVs) are the result of the application of advanced digital electronics to control the operation of the internal combustion engine (ICE). Microprocessors (and micro controllers) play a key role in the engine control, by precisely controlling the amount of both air and fuel admitted into the cylinders. Air intake is controlled by utilizing a throttle valve equipped with a motor and gear mechanism as actuator, and a sensor enabling the measurement of the angular position of the blades. This paperwork presents a lab setup that allows students to control the throttle position using a microcontroller that runs a program developed by them. A commercial throttle body has been employed, whereas a power amplifier and a microcontroller board have been hand assembled to complete the experimental setup. This setup, while based in a high-tech, microprocessor-based solution for a real-world, engine operation optimization problem, has the potential to engage students around a hands-on multidisciplinary lab activity and ignite their interest in learning fundamental and advanced topics of microprocessors systems.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The performance and emissions behavior of a Rover 1S/60 turboshaft engine when operated with several blends of aviation kerosene and ox tallow ethyl-ester are shown in this article. The tests were performed with a compressor shaft coupled to an hydraulic dynamometer where data of power and mass fuel flow were collected to determine the brake specific fuel consumption. A flue gas analyzer was positioned at the exhaust duct to collect oxygen, carbon dioxide, carbon monoxide and nitrous oxides. An increase in the specific fuel consumption was observed due to the lesser lower heating value of the most oxygenated blends. However, reductions of CO, CO2 and NO (x) have been observed and no-significant ill effects have occurred in the turbine operation.
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Pós-graduação em Engenharia Mecânica - FEG
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In worldwide aviation operations, bird collisions with aircraft and ingestions into engine inlets present safety hazards and financial loss through equipment damage, loss of service and disruption to operations. The problem is encountered by all types of aircraft, both military and commercial. Modern aircraft engines have achieved a high level of reliability while manufacturers and users continually strive to further improve the safety record. A major safety concern today includes common-cause events which involve significant power loss on more than one engine. These are externally-inflicted occurrences, with the most frequent being encounters with flocks of birds. Most frequently these encounters occur during flight operations in the area on or near airports, near the ground instead of at cruise altitude conditions. This paper focuses on the increasing threat to aircraft and engines posed by the recorded growth in geese populations in North America. Service data show that goose strikes are increasing, especially in North America, consistent with the growing resident geese populations estimated by the United States Department of Agriculture (USDA). Airport managers, along with the governmental authorities, need to develop a strategy to address this large flocking bird issue. This paper also presents statistics on the overall status of the bird threat for birds of all sizes in North America relative to other geographic regions. Overall, the data shows that Canada and the USA have had marked improvements in controlling the threat from damaging birds - except for the increase in geese strikes. To reduce bird ingestion hazards, more aggressive corrective measures are needed in international air transport to reduce the chances of serious incidents or accidents from bird ingestion encounters. Air transport authorities must continue to take preventative and avoidance actions to counter the threat of birdstrikes to aircraft. The primary objective of this paper is to increase awareness of, and focus attention on, the safety hazards presented by large flocking birds such as geese. In the worst case, multiple engine power loss due to large bird ingestion could result in an off-airport forced landing accident. Hopefully, such awareness will prompt governmental regulatory agencies to address the hazards associated with growing populations of geese in North America.
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In this study, particulate matter (PM) were characterized from a place impacted by heavy-duty vehicles (Bus Station) fuelled with diesel/biodiesel fuel blend (B3) in the city of Londrina, Brazil. Sixteen priority polycyclic aromatic hydrocarbons (PAH) concentrations were analyzed in the samples by their association with atmospheric PM, mass size distributions and major ions (fluorite, chloride, bromide, nitrate, phosphate, sulfate, nitrite, oxalate; fumarate, formate, succinate and acetate; lithium, sodium, potassium, magnesium, calcium and ammonium). Results indicate that major ions represented 21.2% particulate matter mass. Nitrate, sulfate, and ammonium, respectively, presented the highest concentration levels, indicating that biodiesel may also be a significant source for these ions, especially nitrate. Dibenzo[a,h]anthracene and indeno[1,2,3,-cd]pyrene were the main PAH found, and a higher fraction of PAH particles was found in diameters lower than 0.25 mu m in Londrina bus station. The fine and ultrafine particles were dominant among the PM evaluated, suggesting that biodiesel decreases the total PAH emission. However, it does also increase the fraction of fine and ultrafine particles when compared to diesel.
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Models are becoming increasingly important in the software development process. As a consequence, the number of models being used is increasing, and so is the need for efficient mechanisms to search them. Various existing search engines could be used for this purpose, but they lack features to properly search models, mainly because they are strongly focused on text-based search. This paper presents Moogle, a model search engine that uses metamodeling information to create richer search indexes and to allow more complex queries to be performed. The paper also presents the results of an evaluation of Moogle, which showed that the metamodel information improves the accuracy of the search.
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Il panorama delle aziende italiane è costellato da una moltitudine di piccoli attori largamente specializzati in mansioni definite. Sono le piccole e le medie imprese (PMI), aziende per lo più familiari e con meno di qualche decina di dipendenti, talvolta con un'importante storia alle loro spalle che, nonostante la crisi e l'avvento di Internet, sono riuscite a rimanere leader incontrastati nel loro settore. È proprio Internet infatti uno dei pericoli più grandi per esse. Settori che in passato erano presenti offline, negli uffici dove ci si rivolgeva per l'erogazione del servizio richiesto, oggi godono di una fortissima se non predominante attività online, come il settore della ricerca e della selezione del personale. Questo settore, in particolare, ha subito tutta l'influenza di Internet. Annunci, ricerche di lavoro, consulenze, sono quasi totalmente presenti attraverso il canale online. Tale cambiamento ha portato ad una scossa nel mercato, cambiando le modalità di offerta e di domanda dei servizi, determinando chi dovesse sopravvivere e chi no. È Internet stessa ad offrire uno strumento fondamentale per la rivalutazione delle proprie attività e il ritorno di piccole imprese a guidare il mercato, soprattutto nelle realtà locali. Riuscire ad avere il coraggio di affrontare il cambiamento che Internet impone, riorganizzando il proprio lavoro e la propria struttura, è oggi un trampolino di lancio per competere con i grandi head hunter del settore, con aziende del calibro di Monster che sembrano ormai irrangiungibili. Li pensiamo irrangiungibili perché dominanti nei motori di ricerca: sistemi che veicolano attraverso di essi l'informazione e che oggi sono lo strumento che tutti noi quotidianamente utilizziamo per raggiungere le aziende e i loro servizi. I motori di ricerca sono però anche il luogo più democratico della rete. Non sono i soldi o la forza numerica data dell'essere una grande azienda a determinare il posizionamento in essi. È invece la capacità di inviduare e focalizzare il proprio core business che offre la possibilità di primeggiare tra le realtà locali, siano esse a livello provinciale o regionale ad esempio. In queste realtà, in questi settori, non sono i grandi attori internazionali ad avere più possibilità di successo ma sono le attività vicine al territorio ad esserne i leader. Capire questo e agire sulle leve che permettano alle PMI di dirigere il mercato è l'obiettivo di questa tesi. La tesi inizia con una analisi dei principali motori di ricerca italiani, di come sono strutturati e come essi riescono a valutare chi possa essere presente per una determinata keyword e chi non possa esserlo ma soprattutto la qualità attribuita e la posizione assunta. L'argomentazione viene sviluppata su due differenti percorsi: il primo analitico, dove vengono presentati i motori di ricerca, i loro algoritmi, la loro storia e la loro evoluzione futura, per capire come poter essere presenti oggi e come poter esserlo domani. La seconda parte è invece operativa, analizzando Teseo: un'agenzia di ricerca e selezione del personale operante a livello regionale nell'Emilia Romagna e fortemente specializzata in alcune attività molto specifiche. E' stato prodotto un prototipo di sito studiando i punti di forza e le debolezze di sistemi come WordPress e, infine, il lavoro punta alla sua messa online, al confronto tra i risultati raggiunti dal vecchio sito e quelli ottenuti con il nuovo, con una parte finale dedicata a delle attività collaterali e alla valutazione di strategie future sul lungo periodo. Nel settore della ricerca e della selezione del personale via Internet, come può una PMI sopravvivere contro i grandi head hunter?
Analisi e sviluppo di un engine per l'interrogazione di endpoints SPARQL tramite linguaggio naturale
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This research work presents the design and implementation of a FFT pruning block, which is an extension to the FFT core for OFDM demodulation, enabling run-time 8 pruning of the FFT algorithm, without any restrictions on the distribution pattern of the active/inactive sub-carriers. The design and implementation of FFT processor core is not the part of this work. The whole design was prototyped on an ALTERA STRATIX V FPGA to evaluate the performance of the pruning engine. Synthesis and simulation results showed that the logic overhead introduced by the pruning block is limited to a 10% of the total resources utilization. Moreover, in presence of a medium-high scattering of the sub-carriers, power and energy consumption of the FFT core were reduced by a 30% factor.