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141.
Rolf Johansson Michael Verhaegen Chun Tung Chou Anders Robertsson 《International journal of control》2013,86(10):988-995
This paper presents theory and algorithms for validation in system identification of state-space models from finite input-output sequences in a subspace model identification framework. Our formulation includes the problem of rank-deficient residual covariance matrices, a case which is encountered in applications with mixed stochastic-deterministic input-output properties as well as for cases where outputs are linearly dependent. Similar to the case of prediction-error identification, it is shown that the resulting model can be decomposed into an input-output model and a stochastic innovations model. Using the Riccati equation, we have designed a procedure to provide a reduced-order stochastic model that is minimal with respect to system order as well as the number of stochastic inputs thereby avoiding several problems appearing in standard application of stochastic realization to the model validation problem. 相似文献
142.
Heinz E. May T. Born D. Zieger G. Anders S. Zakosarenko V. Meyer H.-G. Schäffel C. 《Journal of Infrared, Millimeter and Terahertz Waves》2015,36(10):879-895
Journal of Infrared, Millimeter, and Terahertz Waves - Passive submillimeter-wave imaging is a concept that has been in the focus of interest as a promising technology for personal security... 相似文献
143.
Lonni Besanon Anders Ynnerman Daniel F. Keefe Lingyun Yu Tobias Isenberg 《Computer Graphics Forum》2021,40(1):293-326
We survey the state of the art of spatial interfaces for 3D visualization. Interaction techniques are crucial to data visualization processes and the visualization research community has been calling for more research on interaction for years. Yet, research papers focusing on interaction techniques, in particular for 3D visualization purposes, are not always published in visualization venues, sometimes making it challenging to synthesize the latest interaction and visualization results. We therefore introduce a taxonomy of interaction technique for 3D visualization. The taxonomy is organized along two axes: the primary source of input on the one hand and the visualization task they support on the other hand. Surveying the state of the art allows us to highlight specific challenges and missed opportunities for research in 3D visualization. In particular, we call for additional research in: (1) controlling 3D visualization widgets to help scientists better understand their data, (2) 3D interaction techniques for dissemination, which are under‐explored yet show great promise for helping museum and science centers in their mission to share recent knowledge, and (3) developing new measures that move beyond traditional time and errors metrics for evaluating visualizations that include spatial interaction. 相似文献
144.
Jeffrey Perl Sahir Kalim Ron Wald Marc B. Goldstein Andrew T. Yan Nazanin Noori Mercedeh Kiaii Julia Wenger Christopher Chan Ravi I. Thadhani S. Ananth Karumanchi Anders H. Berg 《Hemodialysis international. International Symposium on Home Hemodialysis》2016,20(4):510-521
Introduction Among conventional hemodialysis (CHD) patients, carbamylated serum albumin (C‐Alb) correlates with urea and amino acid deficiencies and is associated with mortality. We postulated that reduction of C‐Alb by intensive HD may correlate with improvements in protein metabolism and cardiac function. Methods One‐year observational study of in‐center nocturnal extended hemodialysis (EHD) patients and CHD control subjects. Thirty‐three patients receiving 4‐hour CHD who converted to 8‐hour EHD were enrolled, along with 20 controls on CHD. Serum C‐Alb, biochemistries, and cardiac MRI parameters were measured before and after 12 months of EHD. Findings EHD was associated with reduction of C‐Alb (average EHD change ?3.20 mmol/mol [95% CI ?4.23, ?2.17] compared to +0.21 [95% CI ?1.11, 1.54] change in CHD controls, P < 0.001). EHD was also associated with increases in average essential amino acids (in standardized units) compared to CHD (+0.38 [0.08, 0.68 95%CI]) vs. ?0.12 [?0.50, 0.27, 95% CI], P = 0.047). Subjects who reduced C‐Alb more than 25% were found to have reduced left ventricular mass, increased urea reduction ratio, and increased serum albumin compared to nonresponders, and % change in C‐Alb significantly correlated with % change in left ventricular mass. Discussion EHD was associated with reduction of C‐Alb as compared to CHD, and reduction of C‐Alb by EHD correlates with reduction of urea. Additional studies are needed to test whether reduction of C‐Alb by EHD also correlates with improved clinical outcomes. 相似文献
145.
The proton magnetic resonance spectroscopic imaging techniques that use read gradient during acquisition produce proton spectra
with high spatial and moderately high spectroscopic resolution in a reasonable time forin vivo applications. These techniques suffer mainly from the spatial and pectral distortions caused by the convolution of spectral/spatial
information (chemical-shift artifacts) and from the spectral shifts caused by static magnetic field inhomogeneities. The investigators
analyze the chemical-shift artifacts in the presence of nonnegligible static magnetic field inhomogeneities and propose a
postdetection processing scheme to correct for such effects. Spectral artifacts caused by chemical shifts, spectral line overlapping,
streak broadening, and magnetic field inhomogeneities are discussed. The postdetection data processing scheme is demonstrated
on measurements of a phantom as well as a human leg.
Supported by the Swedish Medical Research Council, project B-96-17x-006676-14A, and by Uppsala University are gratefully acknowledged.
One of us (J.W.) is indebted to the Institute of Measurement Science, Slovak Academy of Sciences, for continuous support,
VEGA Grant No. 95/5305/585,468 & 2/1207/96 相似文献
146.
Phosphorus recovery from the biomass ash: A review 总被引:1,自引:0,他引:1
Biomass ash, generated during the thermal chemical conversion of biomass for energy production, is an industrial by-product which is often recognized as a solid waste, but there are some useful elements in the biomass ash such as phosphorus, etc. So through some technology and methods, the biomass ash can be transferred into a useful resource. The paper mainly includes the following aspects: biomass ash composition characteristics, biomass thermal chemical conversion for phosphorus and phosphorus recovery technology from biomass ash. Through these aspects literature review, not only the whole biomass ash characteristics was made clear, but also we think that the idea of phosphorus from biomass ash is feasible, especially for some high phosphorus ash such as sludge ash, meat and bone meal (MBM) ash, etc. So the review about phosphorus from the biomass ash is very important practical significance for biomass energy, biomass ash disposal and phosphorus resource. 相似文献
147.
Ketut Fundana Niels C. Overgaard Anders Heyden 《International Journal of Computer Vision》2008,80(3):289-299
In this paper we address the problem of segmentation in image sequences using region-based active contours and level set methods.
We propose a novel method for variational segmentation of image sequences containing nonrigid, moving objects. The method
is based on the classical Chan-Vese model augmented with a novel frame-to-frame interaction term, which allow us to update
the segmentation result from one image frame to the next using the previous segmentation result as a shape prior. The interaction
term is constructed to be pose-invariant and to allow moderate deformations in shape. It is expected to handle the appearance
of occlusions which otherwise can make segmentation fail. The performance of the model is illustrated with experiments on
synthetic and real image sequences. 相似文献
148.
Henrik Lindstrm Eva Magnusson Anna Holmberg Sven Sdergren Sten-Eric Lindquist Anders Hagfeldt 《Solar Energy Materials & Solar Cells》2002,73(1):240
The present paper describes a new method for manufacturing a nanostructured porous layer of TiO2 on a conducting glass substrate for use in a dye-sensitized photoelectrochemical cell. The method involves deposition of a layer of semiconductor particles onto a conducting substrate and compression of the particle layer to form a mechanically stable, electrically conducting, and porous nanostructured film at room temperature. Photoelectrochemical characteristics and morphology of the resulting nanostructured films are presented. The potential use of the new manufacturing method in the future applications of nanostructured systems is discussed. 相似文献
149.
Jonas
rtegren Philippe Busson Mikael Lindgren David S. Hermann Per-Otto Arntzen Fredrik Sahlen Mikael Trollss Ulf W. Gedde Anders Hult Lechezar Komitov Sven T. Lagerwall Per Rudquist Bengt Stebler 《Optical Materials》1998,9(1-4):220-225
Second harmonic generation in novel pyroelectric liquid crystal polymers (PLCP) made from a series binary mixtures, was studied using 1100 nm as the fundamental wavelength. The PLCPs were prepared by photo-polymerization of binary mixtures of two monomers which exhibit a smectic C* phase, A2c (4″-(R)-(−)-2-[(10-acrylo-yloxy)decyl]oxy-3-nitrophenyl 4-{4′-[(11-acryloyloxy)-undecyloxy]phenyl}benzoate) and Alb (4″-((R)-(+)-2-octyloxy)-3″-nitrophenyl 4-(4′-(11-acryloyloxy)undecyloxy)-phenyl)-benzoate). The highest d16 and d23 coefficients were found to be in the range 0.65–0.8 pm/V, and differed depending on the detailed preparation of the sample. All cases of polymers formed from the chiral smectic C* phase showed an SHG-signal with no external field present, indicating that polar order became fixed. The SHG-signal was found to increase with the tilt angle of the FLC molecules. 相似文献
150.
Xavier Maurice Anders Sandholm Nicolas Pronost Ronan Boulic Daniel Thalmann 《The Visual computer》2009,25(9):835-842
Today, to create and to simulate a virtual anatomical version of a subject is useful in the decision process of surgical treatments.
The muscular activity is one of the factors which can contribute to abnormal movements such as in spasticity or static contracture.
In this paper, we propose a numerical solution, based on the Finite Element (FE) method, able to estimate muscles deformations
during contraction. Organized around a finite element solver and a volumetric environment, this solution is made of all the
modeling and simulation processes from the discretization of the studied domain to the visualization of the results. The choices
of materials and properties of the FE model are also presented such as the hyperelasticity, the contention model based on
inter-meshes neighboring nodes pairing, and the estimation of nodal forces based on the subject-specific muscular forces and
action lines.
相似文献
Nicolas PronostEmail: |