共查询到10条相似文献,搜索用时 62 毫秒
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In this paper, we develop two new model reference adaptive control (MRAC) schemes for a class of nonlinear dynamic systems that is robust with respect to an uncertain state (output) dependent nonlinear perturbations and/or external disturbances with unknown bounds. The design is based on a controller parametrization with an adaptive integral action. Two types of adaptive controllers are considered—the state feedback controller with a plant parameter identifier, and the output feedback controller with a linear observer. 相似文献
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Jason Sheng-Hong Tsai Meng-Che Wu Leang-San Shieh 《Journal of The Franklin Institute》2005,342(7):852-876
This paper presents a newly developed digital redesign control scheme with a weighted switching strategy and output-reference tracking, for a cascaded analog system with state saturation and external loads. The proposed method improves the generally poor transition response and output deviation caused by state-saturation constraint and external loads. It replaces an existing or theoretically well-designed analog controller with state saturation, by a digital controller with almost identical performance. 相似文献
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Mamatha T. Shenoy Benedicta D’Souza Lalesh Naik Akshatha Vivian D’Souza Madan Gopal Rajan 《Indian journal of clinical biochemistry : IJCB》2015,30(3):360-362
Tumor lysis syndrome has been observed in patients with malignancies with high cellular burden and high cell turnover, tumor sensitive to therapy, especially after initiating medical treatment. It very rarely occurs spontaneously. The case described here is of 6 months male infant who presented with fever since 1 month and loose stools associated with blood since 15 days. The laboratory investigations showed lactate dehydrogenase (LDH) of 6,192 IU/L and serum uric acid 18.2 mg/dl along with pancytopenia. The infant presented with electrolyte abnormalities and renal failure. 相似文献
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Luca Merigo Manuel Beschi Fabrizio Padula Antonio Visioli 《Journal of The Franklin Institute》2018,355(2):774-802
In this paper we propose a new event generator, which has strong noise-filtering capabilities, to be used in event-based control systems with a PIDPlus controller. An approximate frequency analysis is performed in order to characterize the event generator system and tuning guidelines are provided for its design parameter. Simulation and experimental results obtained with a laboratory setup demonstrate the effectiveness of the methodology in providing a satisfactory performance related to set-point and load disturbance step responses with a total variation that is significantly reduced with respect to the standard cases. 相似文献
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Prasanthi Mannava Afshan Masood Ambika K. Devi 《Indian journal of clinical biochemistry : IJCB》2015,30(1):113-116
Albright hereditary osteodystrophy (AHO) is a rare hereditary metabolic disorder that may or may not be associated with resistance to parathyroid hormone (pseudohypoparathyroidism) or other hormones. The disorder is commonly characterized by a constellation of dysmorphic physical features and with biochemical levels that demonstrate hypocalcaemia and hyperphosphatemia. We report here a clinical case of a 14 year old male with AHO and we discuss his clinical features, radiographic and laboratory findings along with treatment. 相似文献
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Cecile Paris Nathalie Colineau Surya Nepal Sanat Kumar Bista Gina Beschorner 《Ethics and Information Technology》2013,15(4):301-316
With the emergence and rapid growth of Social Media, a number of government departments in several countries have embraced Social Media as a privilege channel to interact with their constituency. We are exploring, in collaboration with the Australian Department of Human Services, the possibility to exploit the potential of social networks to support specific groups of citizens. To this end, we have developed Next Step, an online community to help people currently receiving welfare payments find a job and become financially self-sufficient. In this paper, we explore some ethical issues that arise when governments engage directly with citizens, in particular with communities in difficult situations, and when researchers are involved. We describe some of the challenges we faced and how we addressed them. Our work highlights the complexity of the problem, when an online community involves a government department and a welfare recipient group with a dependency relationship with that department. It becomes a balancing act, with the need to ensure privacy of the community members whilst still fulfilling the government’s legal responsibilities. While difficult, these issues must be addressed if governments are to engage with their citizens using Social Media. 相似文献
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Distributed formation control for multiple quadrotor UAVs under Markovian switching topologies with partially unknown transition rates 总被引:1,自引:0,他引:1
Zhen Zhou Hongbin Wang Yueling Wang Xiaojun Xue Mingquan Zhang 《Journal of The Franklin Institute》2019,356(11):5706-5728
This paper addresses distributed formation control for a group of quadrotor unmanned aerial vehicles (UAVs) under Markovian switching topologies with partially unknown transition rates. Instead of the general stochastic topology, the graph is governed by a set of Markov chains to the edges, which can recover the traditional Markovian switching topologies in line with the practical communication network. Extended high gain observers (EHGOs) are constructed with a two-time-scale format to deal with the issue of nonlinear input coefficients, so that there could be a higher estimation precision of the system uncertainties. To impel multiple quadrotor UAVs to achieve a predesigned formation shape, a modified integral sliding mode (ISM) control protocol is proposed here with a multi-time-scale structure, which allows independent analysis of the dynamics in each time scale. The stability proof for the system state space origin is derived from the singular perturbation method and Lyapunov stability theory. In addition, the introduced ISM controller can deal with the time varying desired references with the bounded accelerations and is robust to the disturbances. Finally, simulations on six quadrotor UAVs are given to verify the effectiveness of the theoretical results. 相似文献
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Min Wu Chen Peng Jin Zhang Minrui Fei Yuchu Tian 《Journal of The Franklin Institute》2017,354(12):4955-4965
This paper deals with stability of discrete-time systems with an interval-like time-varying delay. By constructing a novel augmented Lyapunov functional and using an improved finite-sum inequality to deal with some sum-terms appearing in the forward difference of the Lyapunov functional, a less conservative stability criterion is obtained for the system under study if compared with some existing methods. Moreover, as a special case, the stability of discrete-time systems with a constant time delay is also investigated. Three numerical examples show that the derived stability criteria are less conservative and require relatively small number of decision variables. 相似文献