407 resultados para PV tracking factor (TF)


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In this thesis various schemes using custom power devices for power quality improvement in low voltage distribution network are studied. Customer operated distributed generators makes a typical network non-radial and affect the power quality. A scheme considering different algorithm of DSTATCOM is proposed for power circulation and islanded operation of the system. To compensate reactive power overflow and facilitate unity power factor, a UPQC is introduced. Stochastic analysis is carried out for different scenarios to get a comprehensive idea about a real life distribution network. Combined operation of static compensator and voltage regulator is tested for the optimum quality and stability of the system.

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There is an increased interest on the use of UAVs for environmental research and to track bush fire plumes, volcanic plumes or pollutant sources. The aim of this paper is to describe the theory and results of a bio-inspired plume tracking algorithm. A memory based and gradient based approach, were developed and compared. A method for generating sparse plumes was also developed. Results indicate the ability of the algorithms to track plumes in 2D and 3D.

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The mean shift tracker has achieved great success in visual object tracking due to its efficiency being nonparametric. However, it is still difficult for the tracker to handle scale changes of the object. In this paper, we associate a scale adaptive approach with the mean shift tracker. Firstly, the target in the current frame is located by the mean shift tracker. Then, a feature point matching procedure is employed to get the matched pairs of the feature point between target regions in the current frame and the previous frame. We employ FAST-9 corner detector and HOG descriptor for the feature matching. Finally, with the acquired matched pairs of the feature point, the affine transformation between target regions in the two frames is solved to obtain the current scale of the target. Experimental results show that the proposed tracker gives satisfying results when the scale of the target changes, with a good performance of efficiency.

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Despite tough economic times, the uptake of photovoltaic (PV) technology has seen tremendous growth over the past decade. More than 21 GW of rooftop PV systems were installed globally in the year 2012 alone. This is fueled by various incentives offered by policy makers around the world with a goal of enhancing renewable energy integration and reducing the dependence on fossil fuels. For instance, the goal of achieving 20% energy consumption from renewable resources by 2020 has been unanimously accepted by numerous countries in Europe, North America, and Australia. Uptake of PVs by residential and small businesses has been augmented by generous rebates offered by government on installations and on the amount of energy injected into the grid. Furthermore, the global market outlook report published by EPIA predicts that the rooftop PV installations will continue to grow for the foreseeable future.

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There is increasing awareness and concern about law students' elevated distress levels amongst members of the Australian legal academy and the broader legal community. Disproportionately high levels of psychological distress, including depression, anxiety, and substance abuse, have been consistently documented in decades of research on American law student samples. Questions about whether these trends were an American phenomenon, and due to 'differences in demographics, pedagogy and culture' may not apply to Australian law students, began to be empirically addressed with the publication of the Brain and Mind Research Institute's Courting the Blues monograph in 2009. Amongst other findings, the comprehensive research in this monograph indicated that more than one-third of the surveyed law students from Australian universities experience high levels of psychological distress. Recent empirical research at a number of individual Australian law schools reveals similar trends, suggesting that aspects of the legal education experience may contribute to widespread distress levels amongst law students in Australia, as in the United States.

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Stock indexes are passive 'value-weighted' portfolios and should not have alphas which are significantly different from zero. If an index produces an insignificant alphan, then significant alphas for equity funds using this index can be attributed solely to manager performance. However, recent literature sugests that US Stock indexes can demonstrate significant alphas, which ultimately raise questions regarding equity fund manager performance in both the US and abroad. in this paper, we employ the Carhart four-factor model and newly available Asian-Pacific risk factors to generate alphas and risk factor loadings for eight Australian stock indexes from January 2004 to December 2012. We ifnd that the initial full sample period analysis does not provide indication of significant alphas in the indexes examined. However, by carrying out 36-month rolling regressions, we discover at least four significant alphas in seven of the eight indexes and factor loading variability. As previously reported in the US, this paper confirms similar issues with the four-factor model using Australian stock indexes and performance benchmarking. In effectively measuring Australian equity fund manager performance, it is therefore essential to evaluate a fund's alpha and risk factors relative to the alpha and risk factors of the appropriate benchmark index.

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There have been substantial advances in small field dosimetry techniques and technologies, over the last decade, which have dramatically improved the achievable accuracy of small field dose measurements. This educational note aims to help radiation oncology medical physicists to apply some of these advances in clinical practice. The evaluation of a set of small field output factors (total scatter factors) is used to exemplify a detailed measurement and simulation procedure and as a basis for discussing the possible effects of simplifying that procedure. Field output factors were measured with an unshielded diode and a micro-ionisation chamber, at the centre of a set of square fields defined by a micro-multileaf collimator. Nominal field sizes investigated ranged from 6×6 to 98×98 mm2. Diode measurements in fields smaller than 30 mm across were corrected using response factors calculated using Monte Carlo simulations of the full diode geometry and daisy-chained to match micro-chamber measurements at intermediate field sizes. Diode measurements in fields smaller than 15 mm across were repeated twelve times over three separate measurement sessions, to evaluate the to evaluate the reproducibility of the radiation field size and its correspondence with the nominal field size. The five readings that contributed to each measurement on each day varied by up to 0.26%, for the “very small” fields smaller than 15 mm, and 0.18% for the fields larger than 15 mm. The diode response factors calculated for the unshielded diode agreed with previously published results, within 1.6%. The measured dimensions of the very small fields differed by up to 0.3 mm, across the different measurement sessions, contributing an uncertainty of up to 1.2% to the very small field output factors. The overall uncertainties in the field output factors were 1.8% for the very small fields and 1.1% for the fields larger than 15 mm across. Recommended steps for acquiring small field output factor measurements for use in radiotherapy treatment planning system beam configuration data are provided.

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This article critiques the usefulness of habitual residence as the sole connecting factor in Hague Convention child abduction cases. This is achieved by examining the quality of this jurisdiction in light of changes in the gender dynamics underpinning international parental child abduction and the transnational family phenomenon. Arguably, the child’s habitual residence as a home environment of the nature anticipated by the Convention’s drafters is an increasingly outdated construct. This is due to an increase in both the number of abducting primary-carer mothers, and their families’ growing mobility. Judicial determinations of habitual residence made during Conven- tion return proceedings are entrenched in the state-centric paradigm. This paradigm is becoming increasingly incompatible with the lives of families which experience international parental child abduction.

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This paper presents a trajectory-tracking control strategy for a class of mechanical systems in Hamiltonian form. The class is characterised by a simplectic interconnection arising from the use of generalised coordinates and full actuation. The tracking error dynamic is modelled as a port-Hamiltonian Systems (PHS). The control action is designed to take the error dynamics into a desired closed-loop PHS characterised by a constant mass matrix and a potential energy with a minimum at the origin. A transformation of the momentum and a feedback control is exploited to obtain a constant generalised mass matrix in closed loop. The stability of the close-loop system is shown using the close-loop Hamiltonian as a Lyapunov function. The paper also considers the addition of integral action to design a robust controller that ensures tracking in spite of disturbances. As a case study, the proposed control design methodology is applied to a fully actuated robotic manipulator.

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Overvoltage and overloading due to high utilization of PVs are the main power quality concerns for future distribution power systems. This paper proposes a distributed control coordination strategy to manage multiple PVs within a network to overcome these issues. PVs reactive power is used to deal with over-voltages and PVs active power curtailment are regulated to avoid overloading. The proposed control structure is used to share the required contribution fairly among PVs, in proportion to their ratings. This approach is examined on a practical distribution network with multiple PVs.

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A switching control strategy is proposed for single inductor current-fed push-pull converter with a secondary side active voltage doubler rectifier or a voltage rectifier used in photovoltaic (PV) grid interfacing. The proposed switching control strategy helps to turn-on and turn-off the primary side power switches with zero-voltage and zero-current switching. The operation of the push-pull converter is analyzed for two modes of operation. The feasibility of the proposed switching control strategy is validated using simulation and experimental results.

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A high-frequency-link micro inverter is proposed with a front-end dual inductor push-pull converter and a grid-connected half-wave cycloconverter. Pulse width modulation is used to control the front-end converter and phase shift modulation is used at the back-end converter to obtain grid synchronized output current. A series resonant circuit and high-frequency transformer are used to interface the front-end and the back-end converters. The operation of the proposed micro-inverter in grid-connected mode is validated using MATLAB/Simpower simulation. Experimental results are provided to further validate the operation.

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The DeLone and McLean (D&M) model (2003) has been broadly used and generally recognised as a useful model for gauging the success of IS implementations. However, it is not without limitations. In this study, we evaluate a model that extends the D&M model and attempts to address some of it slimitations by providing a more complete measurement model of systems success. To that end, we augment the D&M (2003) model and include three variables: business value, institutional trust, and future readiness. We propose that the addition of these variables allows systems success to be assessed at both the systems level and the business level. Consequently, we develop a measurement model rather than a structural or predictive model of systems success.

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Background Premature aging syndromes recapitulate many aspects of natural aging and provide an insight into this phenomenon at a molecular and cellular level. The progeria syndromes appear to cause rapid aging through disruption of normal nuclear structure. Recently, a coding mutation (c.34G > A [p.A12T]) in the Barrier to Autointegration Factor 1 (BANF1) gene was identified as the genetic basis of Néstor-Guillermo Progeria syndrome (NGPS). This mutation was described to cause instability in the BANF1 protein, causing a disruption of the nuclear envelope structure. Results Here we demonstrate that the BANF1 A12T protein is indeed correctly folded, stable and that the observed phenotype, is likely due to the disruption of the DNA binding surface of the A12T mutant. We demonstrate, using biochemical assays, that the BANF1 A12T protein is impaired in its ability to bind DNA while its interaction with nuclear envelope proteins is unperturbed. Consistent with this, we demonstrate that ectopic expression of the mutant protein induces the NGPS cellular phenotype, while the protein localizes normally to the nuclear envelope. Conclusions Our study clarifies the role of the A12T mutation in NGPS patients, which will be of importance for understanding the development of the disease.

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This research utilised software developed for managing the Australian sugar industry's cane rail transport operations and GPS data used to track locomotives to ensure safe operation of the railway system to improve transport operations. As a result, time usage in the sugarcane railway can now be summarised and locomotive arrival time to sidings and mills can be predicted. This information will help the development of more efficient run schedules and enable mill staff and harvesters to better plan their shifts ahead, enabling cost reductions through better use of available time.