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排序方式: 共有134条查询结果,搜索用时 31 毫秒
21.
This study explores the role of housing expenses and subsidies with respect to income distribution in Flanders (the northern part of Belgium) and the Netherlands in 2005–2006. It analyses income poverty and inequality by comparing equivalent disposable income before and after housing expenses with a relative poverty threshold and the Gini coefficient. Poverty and income inequality increase in both ‘countries’ when equivalent disposable income is corrected for housing expenses. Furthermore, the relative position of outright owners and social tenants regarding poverty improves. Housing subsidies play a (partly) different role in Flanders and the Netherlands. The implicit social rent subsidy in Flanders and the explicit housing allowance in the Netherlands serve the same goal; however, they both redistribute income relatively strongly in favour of low-income tenants. The tax relief system on the other hand increases income inequality in society, in both Flanders and the Netherlands, whereas our comparative analysis suggests that tax relief does not have a moderating effect on net housing expenses. 相似文献
22.
Vunckx K Atre A Baete K Reilhac A Deroose CM Van Laere K Nuyts J 《IEEE transactions on medical imaging》2012,31(3):599-612
In emission tomography, image reconstruction and therefore also tracer development and diagnosis may benefit from the use of anatomical side information obtained with other imaging modalities in the same subject, as it helps to correct for the partial volume effect. One way to implement this, is to use the anatomical image for defining the a priori distribution in a maximum-a-posteriori (MAP) reconstruction algorithm. In this contribution, we use the PET-SORTEO Monte Carlo simulator to evaluate the quantitative accuracy reached by three different anatomical priors when reconstructing positron emission tomography (PET) brain images, using volumetric magnetic resonance imaging (MRI) to provide the anatomical information. The priors are: 1) a prior especially developed for FDG PET brain imaging, which relies on a segmentation of the MR-image (Baete , 2004); 2) the joint entropy-prior (Nuyts, 2007); 3) a prior that encourages smoothness within a position dependent neighborhood, computed from the MR-image. The latter prior was recently proposed by our group in (Vunckx and Nuyts, 2010), and was based on the prior presented by Bowsher (2004). The two latter priors do not rely on an explicit segmentation, which makes them more generally applicable than a segmentation-based prior. All three priors produced a compromise between noise and bias that was clearly better than that obtained with postsmoothed maximum likelihood expectation maximization (MLEM) or MAP with a relative difference prior. The performance of the joint entropy prior was slightly worse than that of the other two priors. The performance of the segmentation-based prior is quite sensitive to the accuracy of the segmentation. In contrast to the joint entropy-prior, the Bowsher-prior is easily tuned and does not suffer from convergence problems. 相似文献
23.
Magnus Röding Hendrik Deschout Thomas Martens Kristof Notelaers Johan Hofkens Marcel Ameloot Kevin Braeckmans Aila Särkkä Mats Rudemo 《Microscopy research and technique》2013,76(10):997-1006
One of the fundamental problems in the analysis of single particle tracking data is the detection of individual particle positions from microscopy images. Distinguishing true particles from noise with a minimum of false positives and false negatives is an important step that will have substantial impact on all further analysis of the data. A common approach is to obtain a plausible set of particles from a larger set of candidate particles by filtering using manually selected threshold values for intensity, size, shape, and other parameters describing a particle. This introduces subjectivity into the analysis and hinders reproducibility. In this paper, we introduce a method for automatic selection of these threshold values based on maximizing temporal correlations in particle count time series. We use Markov Chain Monte Carlo to find the threshold values corresponding to the maximum correlation, and we study several experimental data sets to assess the performance of the method in practice by comparing manually selected threshold values from several independent experts with automatically selected threshold values. We conclude that the method produces useful results, reducing subjectivity and the need for manual intervention, a great benefit being its easy integratability into many already existing particle detection algorithms. Microsc. Res. Tech., 76:997–1006, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
24.
Fatigue damage of materials is an important problem that causes a lot of failures in mechanical systems. It is very important to detect this fatigue as early as possible. Nowadays, most of the nondestructive testing methods are off-line: the inspection is carried out periodically and in some cases the device has to be dismounted. So we risk to exceed, for example, the critical length of a crack. In this article, an on-line method based on the variation in transmission of a multisine ultrasonic wave during opening and closing of a surface crack is developed. As a validation experiment, a propagation fatigue crack in a sinusoidally loaded wing panel is considered. It will be shown that the on-line method is very sensitive to crack propagation. 相似文献
25.
Kristof Pulinckx 《模型世界》2019,(5)
<正>著名的AT-AT,或者叫全地形装甲运输单位是全世界范围内《星球大战》的粉丝都非常热衷于的一台载具。它首次出现在1980年早期上映的《星球大战:帝国反击战》中,因为它庞大的体型、强大的火力和装甲吸引了无数的眼球,当然,仅仅是外观和它行走时的声响就已经很震撼了。但奇怪的是这一题材在市场上一直没有新的板件出品,直到在2017年万代(BANDAI)发行了它们的1/144比例套件。这套板件本身细节非常出色,你甚至可以发现有些板件是还原自设计师对于这一机甲 相似文献
26.
We propose an automatic method for derivinglinear size relations, which specify, with respect to some given norm, linear relationships between the sizes of the arguments of atoms in the least Herbrand model of a definite Horn clause program. The method is presented as an application of abstract interpretation. Its abstract domain consists of affine subspaces or linear varieties, and operations on elements of the domain are expressed in terms of operations from linear algebra. The main application of the technique is situated in automatic termination analysis. Others are complexity and granularity analysis and the specialisation of constraints in constraint logic languages. 相似文献
27.
H Urbach R Kristof J Zentner D Brechtelsbauer L Solymosi HK Wolf 《Canadian Metallurgical Quarterly》1997,39(7):516-519
Sarcoidosis may also present as an extra- or intra-axial mass involving the central nervous system. These lesions are sometimes operated upon, because a neoplasm is suspected. We report two cases of unusual tumour-like extra- and intra-axial sarcoidosis. The extra-axial mass was just medial to the jugular foramen. Its morphology and signal characteristics differed from the more common lesions in this area. The intra-axial mass was in the temporal lobe, with only minor leptomeningeal involvement. Extra-axial sarcoidosis can be confused with a meningioma because these lesions can give relatively low signal on T2-weighted images. Intra-axial masses are presumed to represent a propagation and fusion of multiple leptomeningeal granulomas through the Virchow-Robin spaces in the brain; this pattern can be sought on contrast-enhanced T1-weighted images. 相似文献
28.
Peter W. Kimball Evan B. Clark Mark Scully Kristof Richmond Chris Flesher Laura E. Lindzey John Harman Keith Huffstutler Justin Lawrence Scott Lelievre Joshua Moor Brian Pease Vickie Siegel Luke Winslow Donald D. Blankenship Peter Doran Stacy Kim Britney E. Schmidt William C. Stone 《野外机器人技术杂志》2018,35(2):299-308
The ARTEMIS docking system demonstrates autonomous docking capability applicable to robotic exploration of sub‐ice oceans and sub‐glacial lakes on planetary bodies, as well as here on Earth. In these applications, melted or drilled vertical access shafts restrict vehicle geometry as well as the in‐water infrastructure that may be deployed. The ability of the vehicle to return reliably and precisely to the access point is critical for data return, battery charging, and/or vehicle recovery. This paper presents the mechanical, sensor, and software components that make up the ARTEMIS docking system, as well as results from field deployment of the system to McMurdo Sound, Antarctica in the austral spring of 2015. The mechanical design of the system allows the vehicle to approach the dock from any direction and to pitch up after docking for recovery through a vertical access shaft. It uses only a small volume of in‐water equipment and may be deployed through a narrow vertical access shaft. The software of the system reduces position estimation error with a hierarchical combination of dead reckoning, acoustic aiding, and machine vision. The system provides critical operational robustness, enabling the vehicle to return autonomously and precisely to the access shaft and latch to the dock with no operator input. 相似文献
29.
Anna M. Kaczmarek Ying‐Ya Liu Chunhua Wang Brecht Laforce Laszlo Vincze Pascal Van Der Voort Kristof Van Hecke Rik Van Deun 《Advanced functional materials》2017,27(20)
Hybrid materials displaying multistage security behavior, where a single material shows both wavelength‐ and temperature‐dependent luminescence properties, are reported. The materials consist of mixed‐lanthanide β‐diketonate complexes grafted into the pores of a nanosized 2,2′‐bipyridine‐5,5′‐dicarboxylate‐acid MOF. A very specific choice of lanthanides and their ratios, as well as β‐diketonate ligand, is crucial for obtaining the desired properties. The wavelength‐dependent luminescence properties of the materials are very well matched with the excitation wavelengths of a standard UV lamp, and a clearly visible change in luminescence is observed in a narrow temperature range (slightly below and above room temperature), proving them to be excellent materials for use in anti‐counterfeit technologies, which would be almost impossible to mimic. 相似文献
30.
Kristof Altmann Simon Stingelin Fredi Tröltzsch 《International Journal of Circuit Theory and Applications》2014,42(8):808-830
Some optimal control problems for linear and nonlinear ordinary differential equations related to the optimal switching between different magnetic fields are considered. The main aim is to move an electrical initial current by a controllable voltage in shortest time to a desired terminal current and to hold it afterwards. Necessary optimality conditions are derived by Pontryagin's principle and a formal Lagrange technique. In the case of a linear system, the principal structure of time‐optimal controls is discussed. The associated optimality systems are solved by a one‐shot strategy using a multigrid software package. Various numerical examples are discussed. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献