972 resultados para Power control


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Within Australia, very little attention has been given to the potential biodiversity benefits of power line easements, if ecologically sensitive management regimes are developed. This study examined the potential power line easements may have for the conservation of small mammals, and in particular the near threatened, Broad-toothed Rat Mastacomys fuscus, in Australia. Easement vegetation was found to support a diverse small mammal community, including M. fuscus if the vegetation was allowed to develop some structural complexity. M. fuscus was one of the first species to recolonize the easement habitat, provided that the areas had regenerated to a sufficient level. Results suggests; however, that the current management technique used, where the entire easement is managed at one time via mass slashing, on short rotation times, is most likely limiting M. fuscus to low abundances, and causing isolation of the current M. fuscus populations. To ensure that power line easements supply functional, usable habitat for small mammals and other species and to minimize their potential to fragment small mammal populations, it is recommended that current management techniques be reassessed. In an effort to develop more appropriate management regimes, it was recommended that rotation times be increased between management, that mass slashing of the easement at one time be reassessed, especially in naturally low growing areas and that rotational type slashing be implemented. Other techniques such as spot spraying, may be all that is needed within some areas to control emergent saplings. This study highlights that potential biodiversity values do exist for Australian power line easements, if some changes occur to the current management practices.

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This paper concerns the adaptive fast finite time control of a class of nonlinear uncertain systems of which the upper bounds of the system uncertainties are unknown. By using the fast non-smooth control Lyapunov function and the method of so-called adding a power integrator merging with adaptive technique, a recursive design procedure is provided, which guarantees the fast finite time stability of the closed-loop system. It is proved that the control input is bounded, and a simulation example is given to illustrate the effectiveness of the theoretical results.

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South Asia has emerged in the post-Cold War era as a region where ongoing nuclear rivalry has the potential to result in a nuclear exchange between India and Pakistan. The United States, together with the global community, is devoting considerable effort to prevent the further development and deployment of nuclear weapons by India and Pakistan. This thesis analyses the underlying reasons for the ongoing nuclear rivalry between India and Pakistan, details post-Cold War initiatives to end the nuclear rivalry and examines the prospect of United States efforts to cap, reduce and eventually eliminate the nuclear arsenals of India and Pakistan. The thesis finds that historical factors form the basis of the continuing hostility and animosity between the two nations. The two nations have been bitter rivals since the time of partition in 1947 and the disputed territory of Kashmir continues to be the manifestation of deep seated antagonism and hostility. Pakistan's geography leaves it extremely vulnerable to conventional Indian attack and possession of nuclear weapons is seen as a means to redress the imbalance. Strong domestic support together with fervent nationalism and international prestige will continue to drive the nuclear programs of each nation. This thesis concludes that the nuclear rivalry between India and Pakistan is regional in nature and the end of the Cold War has done little to improve the prospects for nuclear disarmament in the region. United States led efforts have failed to persuade India or Pakistan to either accede to the Non-Proliferation Treaty (NPT) or dismantle their nuclear weapons. The thesis also notes that the United States has failed to take account of China as a significant regional power and it's impact on the nuclear programs of India and Pakistan. A fresh approach (to include China) with more emphasis on regional dialogue is suggested as a first step to ending the nuclear rivalry.

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An exploration of women's experience of tubal ligation and the social context in which their contraceptive decision making occurs. This study gives priority to women's knowledge about their own bodies and investigates how women negotiate contraceptive risks, the information provision process, the outcome of tubal ligation in terms of side-effects and the medical responses to women's reporting of their problems. It makes recommendations about the information women should have to meet the requirement of an informed consent when accepting contraceptive surgery.

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Fuel efficiency in a hybrid electric vehicle requires a fine balance between usage of combustion engine and battery power. Information about the geometry of the road and traffic ahead can have a great impact on optimized control and the power split between the main parts of a hybrid electric vehicle. This paper provides a survey on the existing methods of control and energy management emphasizing on those that consider the look-ahead road situation and trajectory information. Then it presents the future trends in the control and energy management of hybrid electric vehicles.

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Hybrid electric vehicles are powered by an electric system and an internal combustion engine. The components of a hybrid electric vehicle need to be coordinated in an optimal manner to deliver the desired performance. This paper presents an approach based on direct method for optimal power management in hybrid electric vehicles with inequality constraints. The approach consists of reducing the optimal control problem to a set of algebraic equations by approximating the state variable which is the energy of electric storage, and the control variable which is the power of fuel consumption. This approximation uses orthogonal functions with unknown coefficients. In addition, the inequality constraints are converted to equal constraints. The advantage of the developed method is that its computational complexity is less than that of dynamic and non-linear programming approaches. Also, to use dynamic or non-linear programming, the problem should be discretized resulting in the loss of optimization accuracy. The propsed method, on the other hand, does not require the discretization of the problem producing more accurate results. An example is solved to demonstrate the accuracy of the proposed approach. The results of Haar wavelets, and Chebyshev and Legendre polynomials are presented and discussed. © 2011 The Korean Society of Automotive Engineers and Springer-Verlag Berlin Heidelberg.

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Global public health agreements are heralded as a success for the affirmation of the right to health within a complex and contested political landscape. However, the practical implementation of such agreements at the national level is often overlooked. This article outlines two radically different global health agreements: The Doha Declaration on the Trade-Related Aspects of Intellectual Property Rights (TRIPS) agreement and Public Health; and the Framework Convention on Tobacco Control (FCTC). We identify significant challenges in their implementation, particularly for low and middle income countries. Shifts in the policy network constellations around these two agreements have allowed for some positive influence by civil society. Yet industry influence at the national level constrains effective implementation and those affected by these policies have largely been left on the periphery. The broader provisions of these two agreements have been watered down by vested interests and donor conditions. We advocate for both activist and academic actors to play a significant role in highlighting the consequences of these power asymmetries. Deliberative democracy may be the key to addressing these challenges in a way that empowers those presently excluded from effective participation in the policy process.

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Relationships of authority and control and their effect on information systems actors has interested IS researchers since at least the 1980’s. The study of power itself has also troubled organisational and sociological theorists, from which information systems researchers have drawn various lines of attack. Our approach to power rests on an historical synchronic theory that seeks to uncover the places and operation of power through an examination of narrative ‘testaments’ which are analysed not from the perspective of the giving individual but from the structural elements of discourse that they may represent. This paper compliments previous research methods on the topic of power especially in expert reports and systems development methodologies; provides specific guidance on how to apply the notion of discourse synchronically; and reconstructs the commercial practice of information systems, not as a broad church, but as one of competing and epistemologically incommensurate discourse, where the fates of the powerful are balanced against the fearful and silent disciplined.

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This paper concerns the adaptive fast finite-time multiple-surface sliding control (AFFTMSSC) problem for a class of high-order uncertain non-linear systems of which the upper bounds of the system uncertainties are unknown. By using the fast control Lyapunov function and the method of so-called adding a power integrator merging with adaptive technique, a recursive design procedure is provided, which guarantees the fast finite-time stability of the closed-loop system. Further, it is proved that the control input is bounded.

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This letter presents a novel approach to the load-frequency control (LFC) of interconnected power systems. Based on functional observers theory, quasi-decentralized functional observers (QDFOs) are designed to implement any given global PI state feedback controller. The designed functional observers are decoupled from each other and also of low-order; thus, they are cost effective and easy to implement. Although the proposed approach is applicable to N- area power systems, an example of a two-area interconnected power system with reheat thermal turbines is considered for simplicity.

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Effect of weighted vest suit worn during daily activities on running speed, jumping power, and agility in young men. J Strength Cond Res 26(11): 3030-3035, 2012-Previous weighted vest interventions using exercise in addition to hypergravity have been successful in improving postural balance and power production capacity. The purpose of this study was to investigate if hypergravity alone in daily activities excluding sporting activities is effective in improving neuromuscular performance in young adults. Eight male subjects (age = 32 [SD: 6] years, height = 178 [5] cm, and body mass = 81 [8] kg) wore weighted vests 3 d.wk-1 for 3 weeks during waking hours, excluding sporting activities. Control group comprised 9 male subjects (age = 32 [6] years, height = 179 [5] cm, and body mass = 83 [9] kg). Performance was assessed with countermovement jump (body mass normalized peak power), figure-of-8 running test (running time), and running velocity test at baseline and at the end of the intervention. At baseline, the groups did not differ from each other (multivariate analysis of variance [MANOVA] p = 0.828). A significant group × time interaction (MANOVA F = 5.1, p = 0.015) was observed for performance variables. Analysis of covariance indicated that the intervention improved the figureof- 8 running time (p = 0.016) (22.2 vs. 0.5%), whereas normalized peak power (0.0 vs. 1.6%) and running velocity (1.3 vs. 0.1%) were unaffected (p ≥ 0.095). Wearing weighted vests was effective in slightly improving agility-related performance in young men. Because the effect was small, applying hypergravity only during exercise probably suffices. It appears that a proper volume and intensity of hypergravity could be in the order of 5-10% body weight vest worn during up to 50% of the training sessions for a period of 3-4 weeks.