Global W2,pW^{2,p} estimates for solutions to the linearized Monge--Amp\`ere equations

In this paper, we establish global $W^{2,p}$ estimates for solutions to the linearized Monge-Amp\`ere equations under natural assumptions on the domain, Monge-Amp\`ere measures and boundary data. Our estimates are affine invariant analogues of the global $W^{2,p}$ estimates of Winter for fully nonlinear, uniformly elliptic equations, and also linearized counterparts of Savin's global $W^{2,p}$ estimates for the Monge-Amp\`ere equations.Comment: v2: presentation improve

An efficient ant colony system based on receding horizon control for the aircraft arrival sequencing and scheduling problem

The aircraft arrival sequencing and scheduling (ASS) problem is a salient problem in air traffic control (ATC), which proves to be nondeterministic polynomial (NP) hard. This paper formulates the ASS problem in the form of a permutation problem and proposes a new solution framework that makes the first attempt at using an ant colony system (ACS) algorithm based on the receding horizon control (RHC) to solve it. The resultant RHC-improved ACS algorithm for the ASS problem (termed the RHC-ACS-ASS algorithm) is robust, effective, and efficient, not only due to that the ACS algorithm has a strong global search ability and has been proven to be suitable for these kinds of NP-hard problems but also due to that the RHC technique can divide the problem with receding time windows to reduce the computational burden and enhance the solution's quality. The RHC-ACS-ASS algorithm is extensively tested on the cases from the literatures and the cases randomly generated. Comprehensive investigations are also made for the evaluation of the influences of ACS and RHC parameters on the performance of the algorithm. Moreover, the proposed algorithm is further enhanced by using a two-opt exchange heuristic local search. Experimental results verify that the proposed RHC-ACS-ASS algorithm generally outperforms ordinary ACS without using the RHC technique and genetic algorithms (GAs) in solving the ASS problems and offers high robustness, effectiveness, and efficienc

Tension in the curve

This artist’s book is a meditative narrative on my making and exploration of materiality. It’s the best way to allow you entry and understanding into how I see. Finding the tension in the curve and the lines and shadow and light that are created, These new forms that appear when stress occurs help me understand

The future of bioethanol

Yeasts have been domesticated by mankind before horses. After the mastering of alcoholic fermentation for centuries, yeasts have become the protagonist of one of the most important biotechnological industries worldwide: the production of bioethanol. This chapter will initially present some important challenges to be overcome in this industry, both in first and second generation biofuel production. Then, it will briefly revisit some advances obtained in recent years. Finally, it will present and discuss some opportunities, in the scope of metabolic engineering and synthetic biology, that will likely be present in the future of bioethanol

Differences in Vitrification Behaviour of Flint and Opaque Scrap Glass Containing Porcelainized Stoneware Body

In a normal stoneware ceramic composition, feldspar was partially substituted by two types soda lime silica scrap glass powder (flint-chromium free and opaque-chromium doped). Samples were fired in the temperature range of 1100–1250 °C and their physico-mechanical properties were studied and compared with the normal composition.Samples containing flint glass powder achieved early vitrifi cation at 1200 °C compared to 1250 °C for opaque glass containing sample as well as normal stoneware body. Both bodies achieved more than 40 MPa flexural strength at their vitrifi cation temperature. Formation of needle shaped mullite crystals was observed in all samples. Presence of large number of smaller size mullite crystals was responsible for strength development

Activity and Corresponding Mass Concentrations of 40K and 238U in Well Waters from Ago-Iwoye, Ogun State, Nigeria

Ago-Iwoye, situated on the basement complex has similar geological setting to Abeokuta which had been reported to be significantly high in radioactivity when compared to the world’s average. The major source of water for the populace in Ago-Iwoye was from the wells dug at different locations across the town. The 238U and 40K concentrations in the water samples were measured using gamma-ray spectroscopy method and the health risks due to consumption of the waters were determined. The mean activity concentrations were 25.1±10.7 Bql-1 for 40K and 3.1±2.9 Bql-1 for 238U. The corresponding mean mass concentrations for 40K and 238U were 462.02±217.47 µgl-1 and 52.6±53.18µgl-1 respectively. The mean cancer mortality and morbidity risks due to 238U in the well water samples were respectively (1.09±1.11) x 10-4 and (1.68±1.69) x 10-4. The cancer mortality and morbidity risks were less than the reported world average of 1.0x10-3. Keywords: Ago-Iwoye, radiological effects, well waters, cancer mortality, basement complex

Design of Sievenpiper HIS for use in planar broadband antennas by means of effective medium theory

The claim for multistandard operating handsets of small physical size as well as the ever increasing demand for higher data rates require new broadband operating antennas. Because of the widespread use of especially planar broadband antennas a lot of factors influencing the characteristic antenna parameters have to be regarded. Furthermore, aspects regarding the electromagnetic compatibility inside the handheld as well as the protection of biological systems, e.g. the user of a mobilephone, have to be payed attention to. An electromagnetic structure which allows for protection by means of shielding as well as enhances the antennas efficiency by providing unique electromagnetic properties are the so called Sievenpiper High Impedance Surfaces (HIS) invented by Sievenpiper (1999). This paper will present the theory and the well known design equations for those structures. An investigation by means of simulation tools and measurement setups will be done to approve the accuracy of the theoretical results. Here measurement results of the impedance and radiation properties of a planar log.-per. fourarm antenna equiped in conjunction with a fabricated prototype Sievenpiper HIS will be presented

Sievenpiper HIS and its influence on antenna correlation

This paper deals with the influence of artificial magnetic conductors (AMC), so-called Sievenpiper High Impedance Surfaces (HIS), on the MIMO and Diversity performance of a planar linear-polarized 2×2 dipole array in the ISM-band at 2.45 GHz. The characteristic performance criteria such as envelope correlation coefficient, spectral efficiency, Mean Effective Gain (MEG) and Diversity gain of a coupled 2×2 dipole array are investigated. By means of full-wave electromagnetic analysis as well as Monte-Carlo simulations applying statistical channel models the characteristic antenna pattern just as the MIMO and Diversity analysis is performed, respectively. The obtained results show that the application of Sievenpiper High Impedance Surfaces to planar antenna arrays enables good MIMO and Diversity performance compared to ideal configurations in free-space while offering the design of low profile antennas with simultaneously enhanced characteristics. © Author(s) 2008

Progress in the control of schistosomiasis in Zimbabwe since 1984

A clinical study on the measures taken in the management and control of Schistosomiasis as a public health problem in Zimbabwe since 1984.Schistosomiasis remains the second most important parasitic disease in Zimbabwe. In terms of its combined morbidity and prevalence, schistosomiasis is thought to be the most important helminth infection of man. Since 1984, a number of control programmes have commenced around the country and a national control programme aimed at reducing morbidity is being implemented. The strategy adopted in Zimbabwe is a community based approach integrated in the primary health care syste

Considering even-order terms in stochastic nonlinear system modeling with respect to broadband data communication

As a tradeoff between efficiency and costs modern communication systems contain a variety of components that can at least be considered weakly nonlinear. A critical element in evaluating the degree of nonlinearity of any underlying nonlinear system is the amount of undesired signal strength or signal power this system is introducing outside the transmission bandwidth. This phenomenon called spectral regrowth or spectral broadening is subject to stringent restrictions mainly imposed by the given specifications of the particular communication standard. Consequently, achieving the highest possible efficiency without exceeding the linearity requirements is one of the main tasks in system design. Starting from this challenging engineering problem there grows a certain need for specialized tools that are capable of predicting linearity and efficiency of the underlying design. Besides a multitude of methods aiming at the prediction of spectral regrowth a statistical approach in modeling and analyzing nonlinear systems offers the advantage of short processing times due to closed form mathematical expressions in terms of input and output power spectra and is therefore further examined throughout this article