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41.
We extend the traditional notion of passivity to a forced system whose equilibrium is dependent on the control input by defining equilibrium-independent passivity, a system property characterized by a dissipation inequality centered at an arbitrary equilibrium point. We provide a necessary input/output condition which can be tested for systems of arbitrary dimension and sufficient conditions to certify this property for scalar systems. An example from network stability analysis is presented which demonstrates the utility of this new definition. We then proceed to numerical certification of equilibrium-independent passivity using sum-of-squares programming. Finally, through numerical examples we show that equilibrium-independent passivity is less restrictive than incremental passivity. 相似文献
42.
Permanent international river basin organizations (IRBOs) come in many shapes and sizes, ranging from those which are mainly facilitative in nature to those empowered to act on their own. Although differences in IRBO types may have important impacts on transboundary water resources management, systematic analysis of variation in their structure and responsibilities is scant. This paper synthesizes and applies a typology to determine the structural composition, abundance, spatial distribution, scale and in-basin configurations of the different forms of IRBOs. The results provide a set of options for future IRBOs, and serve to ground-truth and nuance theoretical divisions between different types of organizations in transboundary basins. 相似文献
43.
In this study an agricultural residue, sesame stalk, was evaluated for the removal of Ni(II) and Zn(II) metal ions from aqueous solutions. Biosorption studies were carried out at different pH, biosorbent dosage, initial metal ion concentrations, contact time, and solution temperature to determine the optimum conditions. The experimental data were modeled by Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Temkin isotherm models. Langmuir model resulted in the best fit of the biosorption data. The pseudo-first-order and pseudo-second-order kinetic models were used to describe the kinetic data and to evaluate rate constants. The best correlation was provided by the second-order kinetic model. The thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated for predicting the nature of adsorption. The experimental results showed that sesame stalk can be used as an effective and low-cost biosorbent precursor for the removal of heavy metal ions from aqueous solutions. 相似文献
44.
Hakk? Murat Genç Osman Kaan Erol?brahim Eksin Mehmet Fatih BerberBinnur Onaran Güleryüz 《Expert systems with applications》2012,39(1):316-327
An appropriate and efficient gate assignment is of great importance in airports since it plays a major role in the revenue obtained from the airport operations. In this study, we have focused mainly on maximum gate employment, or in other words minimize the total duration of un-gated flights. Here, we propose a method that combines the benefits of heuristic approaches with some stochastic approach instead of using a purely probabilistic approach to top-down solution of the problem. The heuristic approaches are usually used in order to provide a fast solution of the problem and later stochastic searches are used in order to ameliorate the previous results of the heuristic approach whenever possible. The proposed method generates an assignment order for the whole planes that corresponds to assignment priority. The ordering process is followed by the allocation step. Since, in practice, each airport has its own physical architecture, there have been arisen many constraints mainly concerning airplane types and parking lots in this step. Sequentially handling the plane ordering and allocation phases provides us great modularity in handling the constraints. The effectiveness of the proposed methodology has been tried to be illustrated firstly on fictively generated flight schedule data and secondly on the real world data obtained from a real world application developed for ?stanbul Atatürk Airport. 相似文献
45.
Erdem Atar E. Sabrikayali Huseyin Cimenoglu 《Metallurgical and Materials Transactions A》2005,36(10):2793-2800
In the present study, the tribological performance of ternary (Zr,Hf)N coatings, whose Hf content was varied between 0 and
21 wt pct, has been systematically examined in the as-deposited and oxidized conditions. Coatings were applied on AISI D2
tool steel plates by arc physical vapor deposition (PVD). Oxidation was conducted at 400 °C for times up to 12 hours in air.
Wear tests revealed pronounced improvement in the wear resistance with increasing Hf content in the as-deposited coatings.
Oxidation for 12 hours yielded more than a fourfold increase in wear resistance. The beneficial effect of Hf on wear resistance
decreased upon oxidation. 相似文献
46.
Nicole Altvater-Mackensen Gregor Balicki Lucie Bestakowa Bianca Bocatius Johannes Braun Lars Brehmer Verena Brune Kirstina Eigemeier F&#;sun Erdem Ralf Fritscher Anne Jacobs Bernd Klingsporn Marcin Kosinski Julia Kuntze Ju-Ra Lee Anna Osterhage Martin Probost Thorsten Risch Tobias Schmitt Wolfgang G. Stock Anja Sturm Katrin Weller Kerstin Werner 《Scientometrics》2005,63(3):463-529
Summary We operationalize scientific output in a region by means of the number of articles (as in the SciSearch database) per year and technology output by means of the number of patent applications (as in the database of the European Patent Office) per priority year. All informetric analyses were done using the DIALOG online-system. The main research questions are the following: Which scientific and technological fields or topics are most influent within a region and which institutions or companies are mainly publishing articles or holding patents? Do the distributions of regional science and technology fields and of publishing institutions follow the well-known informetric function? Are there - as it is expected - only few fields and few institutions which dominate the region? Is there a connection between the economic power of a region and the regional publication and patent output? Examples studied in detail are seven German regions: Aachen, Düsseldorf, Hamburg, Köln (Cologne), Leipzig - Halle - Dessau, München (Munich), and Stuttgart. Three different indicators were used, science and technology attraction of a region (number of scientific articles and patents), science and technology intensity (articles and patents per 1,000 inhabitants), and science and technology density (articles and patents per 1 billion EURO gross value added). Top region concerning both attraction and intensity is Munich, concerning density it is Aachen. 相似文献
47.
Murat Caner Testik 《Quality and Reliability Engineering International》2005,21(2):115-130
As a result of time series parameter estimation based on previous data, the probability content of residuals control charts may vary when standard control limits are used. In this paper, we consider the AR(1) process with the autoregressive parameter being estimated from a sample of observations. The performance of the exponentially weighted moving average (EWMA) control chart for residuals is investigated. Modified control limits that account for the uncertainty in the parameter estimate are provided. Comparisons through simulation signify the importance of the modified control limits. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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This paper reports the presence of Al- O- Al linkages in an aluminosilicate glass where Si/Al = 1 by using 2D17O triple quantum MAS NMR technique (3Q MASNMR). The experiments were performed at external magnetic fields of 8.4 and 14.4T.
Despite17OMAS NMR spectra of the sample in both fields do not give much information about the different kinds of linkages in the sample,
3Q MAS NMR spectrum shows clear evidence that there are some amounts of Al-O-Al linkages in the sample giving two completely
resolved peaks. These two peaks were attributed to the Si-O-Al and Al-O-Al linkages on the basis of their chemical shifts
and, quadrupolar coupling constants which are quite sensitive to the local structure. 相似文献