895 resultados para Management techniques


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Many-core systems are emerging from the need of more computational power and power efficiency. However there are many issues which still revolve around the many-core systems. These systems need specialized software before they can be fully utilized and the hardware itself may differ from the conventional computational systems. To gain efficiency from many-core system, programs need to be parallelized. In many-core systems the cores are small and less powerful than cores used in traditional computing, so running a conventional program is not an efficient option. Also in Network-on-Chip based processors the network might get congested and the cores might work at different speeds. In this thesis is, a dynamic load balancing method is proposed and tested on Intel 48-core Single-Chip Cloud Computer by parallelizing a fault simulator. The maximum speedup is difficult to obtain due to severe bottlenecks in the system. In order to exploit all the available parallelism of the Single-Chip Cloud Computer, a runtime approach capable of dynamically balancing the load during the fault simulation process is used. The proposed dynamic fault simulation approach on the Single-Chip Cloud Computer shows up to 45X speedup compared to a serial fault simulation approach. Many-core systems can draw enormous amounts of power, and if this power is not controlled properly, the system might get damaged. One way to manage power is to set power budget for the system. But if this power is drawn by just few cores of the many, these few cores get extremely hot and might get damaged. Due to increase in power density multiple thermal sensors are deployed on the chip area to provide realtime temperature feedback for thermal management techniques. Thermal sensor accuracy is extremely prone to intra-die process variation and aging phenomena. These factors lead to a situation where thermal sensor values drift from the nominal values. This necessitates efficient calibration techniques to be applied before the sensor values are used. In addition, in modern many-core systems cores have support for dynamic voltage and frequency scaling. Thermal sensors located on cores are sensitive to the core's current voltage level, meaning that dedicated calibration is needed for each voltage level. In this thesis a general-purpose software-based auto-calibration approach is also proposed for thermal sensors to calibrate thermal sensors on different range of voltages.

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Soil erosion and unsustainable land use produce adverse effects on SOC content. Soil management techniques and corrections can be applied for soil recovery, especially, with afforestaion purposes. This study presents the short term effects on the application of different treatments on soil properties for soil included in several sets of closed plots located in the experimental area of Pinarillo (Nerja, Spain). The analysed soil properties were: PH, EC, organic carbon, total nitrogen and total carbon. In order to verify possible differences, we applied the test of Mann-Whitney U in corroboration with the previous homogeneity test of variance.

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L’utilisation rationnelle de l’eau est une préoccupation croissante. Il importe d’optimiser la gestion des irrigations du fraisier à jours neutres afin de répondre adéquatement au besoin de la plante tout en diminuant la pression du secteur agricole sur l’eau. Dans les sols de l’île d’Orléans, la fraction des particules de sol supérieure à 2 mm peut varier de 15 à 30%. L’eau s’écoule principalement verticalement sous le tube de goutte-à-goutte et le mouvement vertical rapide de l’eau entraine un assèchement du sol en bordure de l’andain et une perte de nutriments. Diverses techniques combinées à l’utilisation de tensiomètres peuvent être envisagées afin d’améliorer l’efficacité d’utilisation de l’eau d’irrigation (EUEI) dans ce type de sol. L’irrigation fractionnée, l’ajustement du seuil de déclenchement de l’irrigation selon l’ETc prévisionnelle, l’installation de matelas capillaires sous la zone racinaire et un système de production hors-sol sur butte profilée ont été testés. Le projet avait pour objectif de déterminer l’effet des techniques présentées sur le développement des fraisiers à jours neutres, le rendement, la qualité des fruits, l’EUEI et les propriétés physico-chimiques du sol. Un dispositif en bloc aléatoire comportant cinq traitements a été mis en place à Saint-Jean-de-l’Île-d’Orléans durant deux saisons de production. Le fractionnement de l’irrigation et le système de production hors-sol ont engendré une augmentation non significative du rendement vendable de 10% et 12%, respectivement, par rapport au traitement témoin. Le système hors-sol a toutefois permis d’augmenter significativement de 86% le rendement vendable durant le premier mois de production. L’EUEI a été améliorée par tous les traitements. En raison de sa simplicité et de sa tendance à augmenter le rendement, l’irrigation fractionnée est recommandée pour le type de sol à l’étude.

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Due to increasing integration density and operating frequency of today's high performance processors, the temperature of a typical chip can easily exceed 100 degrees Celsius. However, the runtime thermal state of a chip is very hard to predict and manage due to the random nature in computing workloads, as well as the process, voltage and ambient temperature variability (together called PVT variability). The uneven nature (both in time and space) of the heat dissipation of the chip could lead to severe reliability issues and error-prone chip behavior (e.g. timing errors). Many dynamic power/thermal management techniques have been proposed to address this issue such as dynamic voltage and frequency scaling (DVFS), clock gating and etc. However, most of such techniques require accurate knowledge of the runtime thermal state of the chip to make efficient and effective control decisions. In this work we address the problem of tracking and managing the temperature of microprocessors which include the following sub-problems: (1) how to design an efficient sensor-based thermal tracking system on a given design that could provide accurate real-time temperature feedback; (2) what statistical techniques could be used to estimate the full-chip thermal profile based on very limited (and possibly noise-corrupted) sensor observations; (3) how do we adapt to changes in the underlying system's behavior, since such changes could impact the accuracy of our thermal estimation. The thermal tracking methodology proposed in this work is enabled by on-chip sensors which are already implemented in many modern processors. We first investigate the underlying relationship between heat distribution and power consumption, then we introduce an accurate thermal model for the chip system. Based on this model, we characterize the temperature correlation that exists among different chip modules and explore statistical approaches (such as those based on Kalman filter) that could utilize such correlation to estimate the accurate chip-level thermal profiles in real time. Such estimation is performed based on limited sensor information because sensors are usually resource constrained and noise-corrupted. We also took a further step to extend the standard Kalman filter approach to account for (1) nonlinear effects such as leakage-temperature interdependency and (2) varying statistical characteristics in the underlying system model. The proposed thermal tracking infrastructure and estimation algorithms could consistently generate accurate thermal estimates even when the system is switching among workloads that have very distinct characteristics. Through experiments, our approaches have demonstrated promising results with much higher accuracy compared to existing approaches. Such results can be used to ensure thermal reliability and improve the effectiveness of dynamic thermal management techniques.

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Os Organismos públicos encontram-se, actualmente, a desenvolver estudos a nível dos Sistemas Integrados de Gestão, motivados pela necessidade que existe em adoptar novas técnicas de Gestão capazes de responder às novas exigências de informação. Em termos gerais, os Organismos públicos encontram-se numa fase de viragem na sua actuação, em que surge a necessidade de dispor de novos sistemas de informação capazes de dar resposta às exigências da Nova Gestão Pública. É certo que a Nova Gestão Pública conduz a uma maior motivação, proporcionando uma melhoria na obtenção dos resultados e modernizando a relação entre o controlo das despesas públicas e a prestação de contas a nível dos órgãos do Estado, e onde a uniformização de critérios se apresenta como um dos principais requisitos para criar condições de implementação de uma contabilidade pública que funcione como instrumento de apoio aos utilizadores da informação e, em particular, aos Órgãos de Chefia e Direcção. Este trabalho analisa o caso do Exército Português, como exemplo de um Organismo público que aproveitou a obrigatoriedade de adesão ao novo Regime de Administração Financeira do Estado, para promover a implementação de um Sistema Integrado de Gestão capaz de responder às novas exigências de informação. Analisam-se também as estratégias de actuação e reorientação organizacional utilizadas pelo Exército Português, de modo a permitir o desenvolvimento e implementação do sistema baseado na uniformização de critérios que garanta os requisitos e as técnicas de Gestão capazes de criar condições para desenvolver uma contabilidade pública que funcione como instrumento de apoio à decisão. ABSTRACT; At present, government entities are developing studies at an Integrated Management System level, impelled by the actual need of adopting new Management techniques capable of responding to the new demands regarding Information. ln global terms, government entities are reaching a turning point in its way of acting, due to the arising need of settling new information systems which provide an answer to the demands of the New Public Management. It is assured that the New Public Management leads to a higher motivation, providing an improvement in accomplishing results and modernizing the link between the control of public expenditure and presenting accounts of State Organs. It also presents the criteria standards as one of the main requirements to create implementation conditions of a public accounting which operates as a support mean to the information users and, more specifically, to the Command and Boarding Bodies. This study analyses the Portuguese Army, an example of government entity which seized the obligation of joining the New Public Financial Management Regime to promote the implementation of an Integrated Management System capable of responding to the new information demands. The performing strategies and organizational refocus used by the Portuguese Army are also analyzed in order to allow the development and implementation of the system. It is based in the standard criteria that secure the requirements and Management techniques which enable the progress of a public accounting acting as a support resource in decision-making.

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The state of Florida has one of the most severe exotic species invasion problems in the United States, but little is known about their influence on soil biogeochemistry. My dissertation research includes a cross-continental field study in Australia, Florida, and greenhouse and growth chamber experiments, focused on the soil-plant interactions of one of the most problematic weeds introduced in south Florida, Lygodium microphyllum (Old World climbing fern). Analysis of field samples from the ferns introduced and their native range indicate that L microphyllum is highly dependent on arbuscular mycorrhizal fungi (AMF) for phosphorus uptake and biomass accumulation. Relationship with AMF is stronger in relatively dry conditions, which are commonly found in some Florida sites, compared to more common wet sites where the fern is found in its native Australia. In the field, L. microphyllum is found to thrive in a wide range of soil pH, texture, and nutrient conditions, with strongly acidic soils in Australia and slightly acidic soils in Florida. Soils with pH 5.5 - 6.5 provide the most optimal growth conditions for L. microphyllum, and the growth declines significantly at soil pH 8.0, indicating that further reduction could happen in more alkaline soils. Comparison of invaded and uninvaded soil characteristics demonstrates that L. microphyllum can change the belowground soil environment, with more conspicuous impact on nutrient-poor sandy soils, to its own benefit by enhancing the soil nutrient status. Additionally, the nitrogen concentration in the leaves, which has a significant influence in the relative growth rate and photosynthesis, was significantly higher in Florida plants compared to Australian plants. Given that L. microphyllum allocates up to 40% of the total biomass to rhizomes, which aid in rapid regeneration after burning, cutting or chemical spray, hence management techniques targeting the rhizomes look promising. Over all, my results reveal for the first time that soil pH, texture, and AMF are major factors facilitating the invasive success of L. mcirophyllum. Finally, herbicide treatments targeting rhizomes will most likely become the widely used technique to control invasiveness of L. microphyllum in the future. However, a complete understanding of the soil ecosystem is necessary before adding any chemicals to the soil to achieve a successful long-term invasive species management strategy.

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Adoption of new cattle management practices by Indonesian smallholders occurs less as a ‘technology transfer’ in the classical sense but rather as a series of conscious decisions by farming households weighing risks and resources as well as matching innovations to livelihood strategies. This paper uncovers the context of decisions and communication of innovations by way of social networks. The research looks at two geographically distinct cases where new cattle management practices have been introduced. We apply the lens of a common sense framework initially introduced by Clifford Geertz. Smallholder decisions are analysed within a socio-cultural context and a particular set of resources, risks and livelihood objectives. We show that the respective value placed on land, cattle and food security is central to adoption of new cattle management techniques. Far from accepting everything novel, smallholders are selective and willing to make changes to their farming system if they do not conflict with livelihood strategies. Innovations are communicated through a range of existing social networks and are either matched to existing livelihood strategies or perceived as stepping-stones out of agriculture.

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The following paper presents an evaluation of airborne sensors for use in vegetation management in powerline corridors. Three integral stages in the management process are addressed including, the detection of trees, relative positioning with respect to the nearest powerline and vegetation height estimation. Image data, including multi-spectral and high resolution, are analyzed along with LiDAR data captured from fixed wing aircraft. Ground truth data is then used to establish the accuracy and reliability of each sensor thus providing a quantitative comparison of sensor options. Tree detection was achieved through crown delineation using a Pulse-Coupled Neural Network (PCNN) and morphologic reconstruction applied to multi-spectral imagery. Through testing it was shown to achieve a detection rate of 96%, while the accuracy in segmenting groups of trees and single trees correctly was shown to be 75%. Relative positioning using LiDAR achieved a RMSE of 1.4m and 2.1m for cross track distance and along track position respectively, while Direct Georeferencing achieved RMSE of 3.1m in both instances. The estimation of pole and tree heights measured with LiDAR had a RMSE of 0.4m and 0.9m respectively, while Stereo Matching achieved 1.5m and 2.9m. Overall a small number of poles were missed with detection rates of 98% and 95% for LiDAR and Stereo Matching.

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This paper presents a comprehensive discussion of vegetation management approaches in power line corridors based on aerial remote sensing techniques. We address three issues 1) strategies for risk management in power line corridors, 2) selection of suitable platforms and sensor suite for data collection and 3) the progress in automated data processing techniques for vegetation management. We present initial results from a series of experiments and, challenges and lessons learnt from our project.

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The research team recognized the value of network-level Falling Weight Deflectometer (FWD) testing to evaluate the structural condition trends of flexible pavements. However, practical limitations due to the cost of testing, traffic control and safety concerns and the ability to test a large network may discourage some agencies from conducting the network-level FWD testing. For this reason, the surrogate measure of the Structural Condition Index (SCI) is suggested for use. The main purpose of the research presented in this paper is to investigate data mining strategies and to develop a prediction method of the structural condition trends for network-level applications which does not require FWD testing. The research team first evaluated the existing and historical pavement condition, distress, ride, traffic and other data attributes in the Texas Department of Transportation (TxDOT) Pavement Maintenance Information System (PMIS), applied data mining strategies to the data, discovered useful patterns and knowledge for SCI value prediction, and finally provided a reasonable measure of pavement structural condition which is correlated to the SCI. To evaluate the performance of the developed prediction approach, a case study was conducted using the SCI data calculated from the FWD data collected on flexible pavements over a 5-year period (2005 – 09) from 354 PMIS sections representing 37 pavement sections on the Texas highway system. The preliminary study results showed that the proposed approach can be used as a supportive pavement structural index in the event when FWD deflection data is not available and help pavement managers identify the timing and appropriate treatment level of preventive maintenance activities.

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The feral pig, Sus scrofa, is a widespread and abundant invasive species in Australia. Feral pigs pose a significant threat to the environment, agricultural industry, and human health, and in far north Queensland they endanger World Heritage values of the Wet Tropics. Historical records document the first introduction of domestic pigs into Australia via European settlers in 1788 and subsequent introductions from Asia from 1827 onwards. Since this time, domestic pigs have been accidentally and deliberately released into the wild and significant feral pig populations have become established, resulting in the declaration of this species as a class 2 pest in Queensland. The overall objective of this study was to assess the population genetic structure of feral pigs in far north Queensland, in particular to enable delineation of demographically independent management units. The identification of ecologically meaningful management units using molecular techniques can assist in targeting feral pig control to bring about effective long-term management. Molecular genetic analysis was undertaken on 434 feral pigs from 35 localities between Tully and Innisfail. Seven polymorphic and unlinked microsatellite loci were screened and fixation indices (FST and analogues) and Bayesian clustering methods were used to identify population structure and management units in the study area. Sequencing of the hyper-variable mitochondrial control region (D-loop) of 35 feral pigs was also examined to identify pig ancestry. Three management units were identified in the study at a scale of 25 to 35 km. Even with the strong pattern of genetic structure identified in the study area, some evidence of long distance dispersal and/or translocation was found as a small number of individuals exhibited ancestry from a management unit outside of which they were sampled. Overall, gene flow in the study area was found to be influenced by environmental features such as topography and land use, but no distinct or obvious natural or anthropogenic geographic barriers were identified. Furthermore, strong evidence was found for non-random mating between pigs of European and Asian breeds indicating that feral pig ancestry influences their population genetic structure. Phylogenetic analysis revealed two distinct mitochondrial DNA clades, representing Asian domestic pig breeds and European breeds. A significant finding was that pigs of Asian origin living in Innisfail and south Tully were not mating randomly with European breed pigs populating the nearby Mission Beach area. Feral pig control should be implemented in each of the management units identified in this study. The control should be coordinated across properties within each management unit to prevent re-colonisation from adjacent localities. The adjacent rainforest and National Park Estates, as well as the rainforest-crop boundary should be included in a simultaneous control operation for greater success.

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Navua sedge, a member of the Cyperaceae family, is an aggressive weed of pastures in Fiji, Sri Lanka, Malay Peninsula, Vanuatu, Samoa, Solomons, and Tahiti and is now a weed of pastures and roadsides in north Queensland, Australia. Primarily restricted to areas with an annual rainfall exceeding 2500 mm, Navua sedge is capable of forming dense stands smothering many tropical pasture species. Seventeen herbicides were field tested at three sites in north Queensland, with glyphosate, halosulfuron, hexazinone, imazapic, imazapyr, or MSMA the most effective for Navua sedge control. Environmental problems such as persistence in soil, lack of selectivity and movement off-site may occur using some herbicides at the predicted LC90 control level rates. A seasonality trial using halosulfuron (97.5 g ai/ha) gave better Navua sedge control (84%) spraying March to September than spraying at other times (50%). In a frequency trial, sequential glyphosate applications (2,160 g ae/ha) every two months was more effective for continued Navua sedge control (67%) than a single application of glyphosate (36%), though loss of ground cover would occur. In a management trial, single applications of glyphosate (2,160 to 3,570 g ae/ha) using either a rope wick, ground foliar spraying or a rotary rope wick gave 59 to 73% control, while other treatments (rotary hoe (3%), slashing (-13%) or crushing (-30%)) were less effective. In a second management trial, four monthly rotary wick applications were much more effective (98%) than four monthly crushing applications (42%). An effective management plan must include the application of regular herbicide treatments to eliminate Navua sedge seed being added to the soil seed bank. Treatments that result in seed burial, for example, discing are likely to prolong seed persistence and should be avoided. The sprouting activity of vegetative propagules and root fragmentation needs to also be considered when selecting control options.

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Technological development of fast multi-sectional, helical computed tomography (CT) scanners has allowed computed tomography perfusion (CTp) and angiography (CTA) in evaluating acute ischemic stroke. This study focuses on new multidetector computed tomography techniques, namely whole-brain and first-pass CT perfusion plus CTA of carotid arteries. Whole-brain CTp data is acquired during slow infusion of contrast material to achieve constant contrast concentration in the cerebral vasculature. From these data quantitative maps are constructed of perfused cerebral blood volume (pCBV). The probability curve of cerebral infarction as a function of normalized pCBV was determined in patients with acute ischemic stroke. Normalized pCBV, expressed as a percentage of contralateral normal brain pCBV, was determined in the infarction core and in regions just inside and outside the boundary between infarcted and noninfarcted brain. Corresponding probabilities of infarction were 0.99, 0.96, and 0.11, R² was 0.73, and differences in perfusion between core and inner and outer bands were highly significant. Thus a probability of infarction curve can help predict the likelihood of infarction as a function of percentage normalized pCBV. First-pass CT perfusion is based on continuous cine imaging over a selected brain area during a bolus injection of contrast. During its first passage, contrast material compartmentalizes in the intravascular space, resulting in transient tissue enhancement. Functional maps such as cerebral blood flow (CBF), and volume (CBV), and mean transit time (MTT) are then constructed. We compared the effects of three different iodine concentrations (300, 350, or 400 mg/mL) on peak enhancement of normal brain tissue and artery and vein, stratified by region-of-interest (ROI) location, in 102 patients within 3 hours of stroke onset. A monotonic increasing peak opacification was evident at all ROI locations, suggesting that CTp evaluation of patients with acute stroke is best performed with the highest available concentration of contrast agent. In another study we investigated whether lesion volumes on CBV, CBF, and MTT maps within 3 hours of stroke onset predict final infarct volume, and whether all these parameters are needed for triage to intravenous recombinant tissue plasminogen activator (IV-rtPA). The effect of IV-rtPA on the affected brain by measuring salvaged tissue volume in patients receiving IV-rtPA and in controls was investigated also. CBV lesion volume did not necessarily represent dead tissue. MTT lesion volume alone can serve to identify the upper size limit of the abnormally perfused brain, and those with IV-rtPA salvaged more brain than did controls. Carotid CTA was compared with carotid DSA in grading of stenosis in patients with stroke symptoms. In CTA, the grade of stenosis was determined by means of axial source and maximum intensity projection (MIP) images as well as a semiautomatic vessel analysis. CTA provides an adequate, less invasive alternative to conventional DSA, although tending to underestimate clinically relevant grades of stenosis.

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The study investigates whether there is an association between different combinations of emphasis on generic strategies (product differentiation and cost efficiency) and perceived usefulness of management accounting techniques. Previous research has found that cost leadership is associated with traditional accounting techniques and product differentiation with a variety of modern management accounting approaches. The present study focuses on the possible existence of a strategy that mixes these generic strategies. The empirical results suggest that (a) there is no difference in the attitudes towards the usefulness of traditional management accounting techniques between companies that adhere either to a single strategy or a mixed strategy; (b) there is no difference in the attitudes towards modern and traditional techniques between companies that adhere to a single strategy, whether this is product differentiation or cost efficiency, and c) companies that favour a mixed strategy seem to have a more positive attitude towards modern techniques than companies adhering to a single strategy