7,359 research outputs found
Decentralized H ∞-controller design for nonlinear systems
This paper considers the decentralized H ∞-controller design problem for nonlinear systems. Sufficient conditions for the solution of the problem are presented in terms of solutions of Hamilton-Jacobi inequalities. The resulting design guarantees local asymptotic stability and ensures a predetermined L 2-gain bound on the closed-loop system.published_or_final_versio
Design of reliable controllers for symmetric composite systems:primary contingency case
This paper discusses the reliable controller design problem for symmetric composite systems composed of several identical subsystems. A reliable controller design procedure is presented in terms of the solutions to algebraic Riccati equations. The order of these AREs is much lower than that of the symmetric composite system. The resulting closed-loop system is reliable in that it provide guaranteed internal stability and H∞ performance when all sensors and actuators are operational as well as when the sensors or actuators of a prescribed subsystem experiences an outage.published_or_final_versio
Prevalence of Mycoplasma pneumoniae: A cause for community‑acquired infection among pediatric populaztion
Background: Atypical pneumonia caused by Mycoplasma pneumoniae is a leading cause of mortality among the pediatric age group.Objectives: Our study was designed to know the prevalence of M. pneumoniae in children with community‑acquired pneumonia and the involvement in the cytoadherence to the respiratory epithelium by M. pneumoniae using electron microscopy and immuno‑gold labeling technique.Materials and Methods: A total of 152 children of 1 month to 12 years of age of both sexes attending Hebei Provincial People’s Hospital, Shijiazhuang, Hebei with diagnosed pneumonia were included in the study.Results: Out of 152 children 84 (55.3%) were males, and 68 (44.7%) were females. The mean age of the patients in the control group (50 patients) was 18.5 ± 3 months with 31 (62%) males and 19 (38%) females. IgM antibodies against M. pneumoniae were positive in 84 (55.3%) males and 68 (44.7%) females. Out of 50 patients 9 (18%) were found to positive for IgM M. pneumoniae antibodies of which four (44.4%) males and 5 (55.5%) females were positive. Our study observed that the gold particles were clustered on the filamentous extension of the tip of the cells. Out of 152 serum samples subjected to particle agglutination assay 138 (90.7%) were positive 1:320 titer, 9 were >1:80 and 3 showed titer was >1:40.Conclusion: We suggest that clinicians should consider empirical therapy of broad spectrum antibiotics therapy to cover these atypical pathogens to reduce the severity before obtaining the serological results. From our study, we also suggest electron microscopic and biochemical studies for better diagnosis of these pathogens.Key words: Atypical, community‑acquired pneumonia, electron microscope, gold labelin
A Fiber-Based Laser Ultrasonic System for Remote Inspection of Limited Access Components
Surface and plate waves are commonly used to nondestructively inspect the near-surface region of a solid component for cracks and other defects due to, for example, structural fatigue. One particularly attractive method of generating and detecting such ultrasonic signals is laser based ultrasonics (LBU) [1]. In particular, because it is non-contact (i.e., does not require couplant), LBU can be implemented for inspection of limited access components using optical fibers, requiring only a small cross-sectional area for access. An example can be found in the inspection of internal surfaces of an aircraft wing as shown in Figure 1 where a contact method would obviously be difficult to apply. Furthermore, in cases where extremely high sensitivity is required, bandwidth reduction can be employed by concentrating the laser generated signal into a narrow frequency band
Initial Energy Density of root s = 7 and 8 TeV p-p Collisions at the LHC
Results from the RHIC and LHC experiments show, that in relativistic heavy
ion collisions, a new state of matter, a strongly interacting perfect fluid is
created. Accelerating, exact and explicit solutions of relativistic
hydrodynamics allow for a simple and natural description of this medium. A
finite rapidity distribution arises from these solutions, leading to an
advanced estimate of the initial energy density of high energy collisions.
These solutions can be utilized to describe various aspects of proton-proton
collisions, as originally suggested by Landau. We show that an advanced
estimate based on hydrodynamics yields an initial energy density in
and 8 TeV p+p collisions at LHC on the same order as the critical
energy density from lattice QCD, and a corresponding initial temperature around
the critical temperature from QCD and the Hagedorn temperature. The
multiplicity dependence of the estimated initial energy density suggests that
in high multiplicity pp collisions at the LHC, there is large enough initial
energy density to create a non-hadronic perfect fluid.Comment: 18 pages, 4 figures. Accepted for publication in the Special Issue
"Quark-Gluon Plasma in the Early Universe and in Ultra-Relativistic Heavy-Ion
Collisions" of Universe (ISSN 2218-1997
Pseudolaric acid B as a new class of microtubule destabilizing agent and an effective anti-tumor compound in vivo
published_or_final_versio
The role of an interactive Greenland ice sheet in the coupled climate-ice sheet model EC-Earth-PISM
AbstractIce sheet processes are often simplified in global climate models as changes in ice sheets have been assumed to occur over long time scales compared to ocean and atmospheric changes. However, numerous observations show an increasing rate of mass loss from the Greenland Ice Sheet and call for comprehensive process-based models to explore its role in climate change. Here, we present a new model system, EC-Earth-PISM, that includes an interactive Greenland Ice Sheet. The model is based on the EC-Earth v2.3 global climate model in which ice sheet surface processes are introduced. This model interacts with the Parallel Ice Sheet Model (PISM) without anomaly or flux corrections. Under pre-industrial climate conditions, the modeled climate and ice sheet are stable while keeping a realistic interannual variability. In model simulations forced into a warmer climate of four times the pre-industrial CO2 concentration, the total surface mass balance decreases and the ice sheet loses mass at a rate of about 500 Gt/year. In the climate warming experiments, the resulting freshwater flux from the Greenland Ice Sheet increases 55% more in the experiments with the interactive ice sheet and the climate response is significantly different: the Arctic near-surface air temperature is lower, substantially more winter sea ice covers the northern hemisphere, and the ocean circulation is weaker. Our results indicate that the melt-albedo feedback plays a key role for the response of the ice sheet and its influence on the changing climate in the Arctic. This emphasizes the importance of including interactive ice sheets in climate change projections.</jats:p
Addressing Security Properties in Systems of Systems: Challenges and Ideas
Within growing pervasive information systems, Systems of Systems (SoS) emerge as a new research frontier. A SoS is formed by a set of constituent systems that live on their own with well-established functionalities and requirements, and, in certain circumstances, they must collaborate to achieve a common mission. In this scenario, security is one crucial property that needs to be considered since the early stages of SoS lifecycle. Unfortunately, SoS security cannot be guaranteed by addressing the security of each constituent system separately. The aim of this paper is to discuss the challenges faced in addressing the security of SoS and to propose some research ideas centered around the notion of a mission to be carried out by the SoS.Ministerio dell'Universitá e della Ricerca (Italia) GAUSS 2015KWREMXMinisterio de Economía y Competitividad TIN2016-76956-C3-2-R (POLOLAS
- …