18,992 research outputs found
Design and assessment of a multiple sensor fault tolerant robust control system
This paper presents an enhanced robust control design structure to realise fault tolerance towards sensor faults suitable for multi-input-multi-output (MIMO) systems implementation. The proposed design permits fault detection and controller elements to be designed with considerations to stability and robustness towards uncertainties besides multiple faults environment on a common mathematical platform. This framework can also cater to systems requiring fast responses. A design example is illustrated with a fast, multivariable and unstable system, that is, the double inverted pendulum system. Results indicate the potential of this design framework to handle fast systems with multiple sensor faults
Adaptive Predictive Control Using Neural Network for a Class of Pure-feedback Systems in Discrete-time
10.1109/TNN.2008.2000446IEEE Transactions on Neural Networks1991599-1614ITNN
Effects of duty cycle on the characteristics of a composite surface-emitting organic distributed feedback laser
[[abstract]]Based on the coupled-wave theory, we model the periodic structure and analyze the influence on composite surface-emitting organic distributed feedback (DFB) lasers. Second-order DFB gratings with duty cycles of 0.3, 0.5, and 0.7 patterned by electron-beam lithography were fabricated. The composite active layer consisted of 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H (DCJTB) and poly(N-vinylcarbazole) (PVK) spin-cast on a textured surface. Excited with 532 nm laser pulses, different lasing characteristics and threshold pumping fluences are exhibited. These are explained by the discrepancy in the coupling coefficients and the threshold gains calculated from the proposed model.[[fileno]]2030126010004[[department]]電機工程學
Robust Adaptive Control of a Class of Nonlinear Strict-feedback Discrete-time Systems with Exact Output Tracking
10.1016/j.automatica.2009.07.025Automatica45112537-2545ATCA
A Survey on Urban Traffic Optimisation for Sustainable and Resilient Transportation Network
Nowadays, sustainability and resilience have become a major consideration that cannot be neglected in urban development. People are starting to consider utilizing the urban infrastructure environment to maintain and improve the functionality and availability of the urban system when unexpected events take place. Traffic congestion is always a major issue in urban planning, especially when the vehicles in the roadway keep growing and the local authorities are lack of solutions to manage or distribute the traffics in the city. It has huge impact on urban sustainability and resilience such as overload of the city’s infrastructure, and air pollution, etc. This paper presents a survey on the challenges of developing sustainable and resilient transportation networks and the current urban traffic optimisation methods, as a possible solution to address such challenges. It aims to describe and define the state of the art on the research on sustainable and resilient transportation networks in urban development and a taxonomy of different traffic optimisation methods used for avoiding traffic congestion and improve urban traffic management
PerfWeb: How to Violate Web Privacy with Hardware Performance Events
The browser history reveals highly sensitive information about users, such as
financial status, health conditions, or political views. Private browsing modes
and anonymity networks are consequently important tools to preserve the privacy
not only of regular users but in particular of whistleblowers and dissidents.
Yet, in this work we show how a malicious application can infer opened websites
from Google Chrome in Incognito mode and from Tor Browser by exploiting
hardware performance events (HPEs). In particular, we analyze the browsers'
microarchitectural footprint with the help of advanced Machine Learning
techniques: k-th Nearest Neighbors, Decision Trees, Support Vector Machines,
and in contrast to previous literature also Convolutional Neural Networks. We
profile 40 different websites, 30 of the top Alexa sites and 10 whistleblowing
portals, on two machines featuring an Intel and an ARM processor. By monitoring
retired instructions, cache accesses, and bus cycles for at most 5 seconds, we
manage to classify the selected websites with a success rate of up to 86.3%.
The results show that hardware performance events can clearly undermine the
privacy of web users. We therefore propose mitigation strategies that impede
our attacks and still allow legitimate use of HPEs
A study of high-frequency-fed AC-DC converter with different DC-DC topologies
In this paper, the operation of high-frequency-fed AC-DC converters with different types of DC-DC topologies is presented. Based on the commonly used DC-DC converter topologies, the possibilities of new converter structure are investigated. Using buck and ZETA topologies as examples, the output voltage gain, output load range and switch stress of the converters are analytically studied. Both converter implementation examples will be given and experimentally demonstrated. © IEEE.published_or_final_versio
Monopoles and Holography
We present a holographic theory in AdS_4 whose zero temperature ground state
develops a crystal structure, spontaneously breaking translational symmetry.
The crystal is induced by a background magnetic field, but requires no chemical
potential. This lattice arises from the existence of 't Hooft-Polyakov monopole
solitons in the bulk which condense to form a classical object known as a
monopole wall. In the infra-red, the magnetic field is screened and there is an
emergent SU(2) global symmetry.Comment: 33 pages, 16 figures; v2: ref adde
Adiposity, its related biologic risk factors, and suicide: a cohort study of 542,088 Taiwanese adults
Recent studies in Western nations have shown inverse associations between body mass index (BMI, measured as weight (kg)/height (m)(2)) and suicide. However, it is uncertain whether the association is similar in non-Western settings, and the biologic pathways underlying the association are unclear. The authors investigated these issues in a cohort of 542,088 Taiwanese people 20 years of age or older who participated in a health check-up program (1994-2008); there were 573 suicides over a mean 8.1 years of follow up. There was a J-shaped association between BMI and suicide risk (P for the quadratic term = 0.033) but limited evidence of a linear association (adjusted hazard ratio per 1-standard-deviation increase = 0.95 (95% confidence interval: 0.85, 1.06)); compared with individuals whose BMI was 18.5-22.9, adjusted hazard ratios for those with a BMI /=35 were 1.56 (95% confidence interval: 1.07, 2.28) and 3.62 (95% confidence interval: 1.59, 8.22), respectively. A high waist-to-hip ratio was associated with an increased risk of suicide. There was some evidence for a reverse J-shaped association of systolic blood pressure and high density lipoprotein cholesterol with suicide and an association of higher triglyceride level with increased suicide risk; these associations did not appear to mediate the associations of BMI and waist-to-hip ratio with suicide.postprin
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