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71.
A higher-order unsplit-field perfectly matched layer for the reflectionless truncation of 3-D spherical FDTD lattices 总被引:1,自引:0,他引:1
Konstantinos P. Prokopidis Nikolaos V. Kantartzis Theodoros D. Tsiboukis 《Electrical Engineering (Archiv fur Elektrotechnik)》2002,84(4):173-187
An enhanced higher-order finite-difference time-domain (FDTD) method for the systematic implementation of 3-D reflectionless perfectly matched layers (PML) in spherical coordinates is presented. By establishing a topologically unsplit-field formulation, the novel technique introduces accurate nonstandard schemes that eliminate the notably intricate lattice dispersion errors. Moreover, the wider spatial increments are treated via self-adaptive compact operators, while a mesh expansion process yields a significant reduction of the absorber's depth. For the temporal variable, the proposed method employs a multistage leapfrog integration that guarantees stability and excitation universality. Hence, because of the optimal configuration of the new PML, it attains a critical annihilation of both propagating and spurious wave families, even for complicated domains. Numerical investigation verifies the superiority of the higher-order algorithm via several unbounded radiation and scattering spherical problems. 相似文献
72.
73.
The influence of drop coalescence and breakup on the existence of multiple steady states is studied for a two-phase stirred isothermal reactor where the chemical reaction in the d?ispersed phase obeys the rate expression ? r = kC/(1 + KC)2. The random coalescence model developed by Curl was simulated using a modified Spielman and Levenspiel Monte Carlo technique.For certain range of the coalescence rate, Damköhler number, and dimensionless feed concentration, multiple steady states have been investigated.A special case has also been considered wherein the existence of multiple steady states for finite values of the coalescence rate is contrasted to the unique steady state solution for an infinite coalescence rate. 相似文献
74.
Nikolaos Ioannou Khushi Jain Alan G. Ramsay 《International journal of molecular sciences》2021,22(16)
Accumulating evidence suggests that the tumor microenvironment (TME) is involved in disease progression and drug resistance in B cell malignancies, by supporting tumor growth and facilitating the ability of malignant cells to avoid immune recognition. Immunomodulatory drugs (IMiDs) such as lenalidomide have some direct anti-tumor activity, but critically also target various cellular compartments of the TME including T cells, NK cells, and stromal cells, which interfere with pro-tumor signaling while activating anti-tumor immune responses. Lenalidomide has delivered favorable clinical outcomes as a single-agent, and in combination therapy leads to durable responses in chronic lymphocytic leukemia (CLL) and several non-Hodgkin lymphomas (NHLs) including follicular lymphoma (FL), diffuse large B cell lymphoma (DLBCL), and mantle cell lymphoma (MCL). Recently, avadomide, a next generation cereblon E3 ligase modulator (CELMoD), has shown potent anti-tumor and TME immunomodulatory effects, as well as promising clinical efficacy in DLBCL. This review describes how the pleiotropic effects of IMiDs and CELMoDs could make them excellent candidates for combination therapy in the immuno-oncology era—a concept supported by preclinical data, as well as the recent approval of lenalidomide in combination with rituximab for the treatment of relapsed/refractory (R/R) FL. 相似文献
75.
76.
Nikolaos Thomos Nikolaos V Boulgouris Michael G Strintzis 《IEEE transactions on image processing》2005,14(11):1890-1901
A novel image transmission scheme is proposed for the communication of set partitioning in hierarchical trees image streams over wireless channels. The proposed scheme employs turbo codes and Reed-Solomon codes in order to deal effectively with burst errors. An algorithm for the optimal unequal error protection of the compressed bitstream is also proposed and applied in conjunction with an inherently more efficient technique for product code decoding. The resulting scheme is tested for the transmission of images over wireless channels. Experimental evaluation clearly demonstrates the superiority of the proposed transmission system in comparison to well-known robust coding schemes. 相似文献
77.
Multi-Camera Human Activity Monitoring 总被引:1,自引:0,他引:1
Loren Fiore Duc Fehr Robot Bodor Andrew Drenner Guruprasad Somasundaram Nikolaos Papanikolopoulos 《Journal of Intelligent and Robotic Systems》2008,52(1):5-43
With the proliferation of security cameras, the approach taken to monitoring and placement of these cameras is critical. This
paper presents original work in the area of multiple camera human activity monitoring. First, a system is presented that tracks
pedestrians across a scene of interest and recognizes a set of human activities. Next, a framework is developed for the placement
of multiple cameras to observe a scene. This framework was originally used in a limited X, Y, pan formulation but is extended to include height (Z) and tilt. Finally, an active dual-camera system for task recognition at multiple resolutions is developed and tested. All
of these systems are tested under real-world conditions, and are shown to produce usable results.
This work has been supported by the NSF through grants #IIS-0219863, #CNS-0224363, #CNS-0324864, #IIP-0443945, #CNS-0420836,
#IIP-0726109, and #CNS-0708344. 相似文献
78.
Nikolaos Dimitratos Jose Antonio Lopez-Sanchez Graham J. Hutchings 《Topics in Catalysis》2009,52(3):258-268
The use of renewable feedstocks, derived from biomass, for the chemical industry is discussed. The modern chemical industry
is based around platform chemicals, e.g. ethene, propene, benzene and xylenes, which are readily derived from oil, and using
these intermediates a broad range of finished products can be derived. While it is feasible that biomass can be converted
to syngas and hence to existing key platform chemicals, this loses all of the chemical complexity that is inherent in bio-derived
molecules. In this paper some of the options are considered and, in particular, the oxidation of glucose and glycerol using
gold nanoparticles supported on carbon is described. We also contrast the oxidation of glycerol using supported gold and gold–palladium
alloys prepared using an impregnation technique, since the gold–palladium alloys have been shown to be highly effective for
the oxidation of alcohols and the synthesis of hydrogen peroxide. 相似文献
79.
Vaios T. Karathanos Ioannis Mourtzinos Konstantina Yannakopoulou Nikolaos K. Andrikopoulos 《Food chemistry》2007,101(2):652-658
In the present study, complexes of vanillin with β-cyclodextrin (β-CD) were prepared by the freeze-drying method. The formation of the inclusion complex was confirmed by differential scanning calorimetry (DSC). DSC thermograms indicated that the endothermic peak of vanillin and the physical mixture of vanillin with β-CD, due to the melting of vanillin crystals, were absent in DSC thermograms obtained for the freeze-dried inclusion complex. Moreover, the DSC studies under oxidation conditions indicate that the complex of vanillin with β-CD is protected towards oxidation since it remains intact at temperatures where the free vanillin is oxidising. The structure of the complex in aqueous solutions was established by nuclear magnetic resonance (NMR) studies and specifically by two-dimensional rotational frame NOE spectra. NMR studies showed inclusion of the entire vanillin molecule in the β-CD in a tilted manner and with the aldehyde group in the primary side. The stoichiometry of the complex was 1:1. A phase solubility study was performed by mixing an excess amount of vanillin with aqueous solutions containing increasing amounts of β-CD. The results indicated that the complex of a vanillin/β-CD inclusion is more soluble in water than vanillin alone. 相似文献
80.