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51.
Pascal De Decker Isabelle Pannecoucke 《Journal of Housing and the Built Environment》2004,19(3):293-309
As long as the social rented sector housed traditional families and the allocation procedures were rather loose, there was little commotion about the sector. A combination of a change in family structures, economic changes, and the strengthening of allocation procedures in favour of those most in need did change perceptions. Marginalisation and ghettoisation, especially of high-rise social housing estates, became buzzwords. This paper deals with the causes of these changes and with their implications. The marginalisation discourse calls for enlarging the target groups and estate-specific allocation procedures (to obtain a `social mix'). It illustrates a profound desire to diminish the number of ethnic minorities, single parents, single-person households and all kinds of people with a weak income profile who gain access to social rental housing. Furthermore, this discourse is reaching a crescendo: after it was started in the early 1990s by staff members of local social housing companies, it passed through the union of the social housing companies, the umbrella organisation of the sector, and parliament, reaching its greatest momentum so far in early 2002 when it was adopted by the Flemish housing minister. The counterpoint to this negative discourse is the high degree of satisfaction among social tenants, as observed in a study carried out in 1999. In our paper we will try to explain the background of these opposing trends and the possible consequences for the social rental housing in general and for tenants in particular. 相似文献
52.
SVM handles classification problem only considering samples themselves and the classification effect depends on the characteristics of the training samples but not the current information of classified problem.From the phenomena of data crossing in systems,this paper improves the classification effect of SVM by adding the prior probability item reflecting the classified problem information into the decision function,which fuses the Bayesian criterion into SVM.The detailed deducing process and realizing steps of the algorithm are put forward.It is verified through two instances.The results showthat the new algorithm has better effect than the traditional SVM algorithm,and its robustness and sensitivity are all improved. 相似文献
53.
静稳定性是航空深弹稳定飞行的先决条件,某对称配置的航空深弹静稳设计主要通过调整安定器的外形和相对位置实现。利用CFD方法研究某航空深弹在各种安定器外形参数条件下的流体动力参数,优化在总体接口条件限制下最可能实现的安定器外形设计。通过使用Fluent软件计算结果与试验结果的比较,认为此计算结果可信。 相似文献
54.
55.
极化合成孔径雷达(PolSAR)采用全极化的工作方式可以获取地物的多种特征,利用这些特征对地物进行分类是PolSAR图像的重要应用方向。不同的特征和分类器对分类精度有着较大的影响。提出了一种基于支持向量机(SVM)和能量最小化(EM)的极化SAR图像地物分类方法。该方法选择基于6种散射模型的分解方法(6SD)所得的6部分散射能量、总散射能量span和3个极化相干矩阵旋转域角参数作为SVM的输入,得到图像分类结果,并使用基于图割的能量最小化算法α-expansion对分类结果进行优化。最后使用AIRSAR系统获得的Flevoland地区的数据进行实验,结果表明所提算法可以提高总体分类精度,总体分类精度为95.6%,高于其他方法的92.3%。所提算法可以较大幅度地提高散射机理明显的区域,如建筑、森林、水域、草地等区域的分类精度。另外,结合EM优化结果可以提高所有种类的分类精度,其中在苜蓿、小麦1、小麦2、裸地、草地、油菜籽等区域的分类精度可提高1%以上。 相似文献
56.
Zhang Yuxuan Tao Youkun Yu Zhouyang Lu Jiamei Lim Sung Yul Shao Jing 《Journal of Electroceramics》2020,45(1):29-38
Journal of Electroceramics - In this work, the structure and electrochemical properties of titanate ceramics with in situ Ni exsolution are investigated to identify the structure-performance... 相似文献
57.
Consideration is given to methods for the parallel operation of frequency converters by applying the active load division. The simulation model of the converter is presented. It consists of three parallel independent modules. A new principle of constructing individual modules of a frequency converter and the principle of their communication interface exhibiting resistance to destabilizing effects and allowing safe operation under nominal conditions even with a 5- to 10% range in time and amplitude values of pilot signals are developed. 相似文献
58.
Alisson Rodrigo Souza Reis Sineire Maria Silva Araújo Paulo Ricardo Rodrigues Piovesan 《Holz als Roh- und Werkstoff》2018,76(6):1761-1763
The objective of this study was to anatomically characterize the fibers of nine species of Fabaceae lianas, to determine their potential in papermaking and to define which biometric parameters can be used to distinguish and identify individuals. The species presented average values of 76.81, 57.45, 42.55, and 1.81 for the felting index, wall fraction, coefficient of flexibility, and Runkel index, respectively. It is concluded that only M. ferox and M. madeirense can be recommended for papermaking. 相似文献
59.
The impact of natural and artificial weathering on the visual,colour and structural changes of seven tropical woods 总被引:1,自引:0,他引:1
Ladislav Reinprecht Miroslava Mamoňová Miloš Pánek František Kačík 《Holz als Roh- und Werkstoff》2018,76(1):175-190
This study investigates the effects of wood weathering on changes in its macroscopic and colour characteristics in connection with changes in its molecular and anatomical structure. Seven hardwoods suitable for outdoor architecture—bangkirai, cumaru, cumaru rosa, ipé, jatobá, kusia, and massaranduba—were exposed to the exterior out of ground contact for 1–36 months according to EN 927-3, and for 1–12 weeks in Xenotest with water spraying according to partly modified EN 927-6. With prolonged weathering, the following changes occurred in the top surfaces of all tropical woods: (1) visual—creation of longitudinal macro-cracks, (2) spectrophotometry and CIE-L ? a ? b ? —darkening in exterior exposure mainly due to pollutants, except for ipé, and vice versa lightening in Xenotest, as well as greening and blueing in both modes of exposure, (3) FTIR—faster decrease of guaiacyl than syringyl lignin, absolute decrease of conjugated and unconjugated carbonyl groups in the newly formed lignin-polysaccharide-extractive substrate in the photo-oxidized and washed-out cell walls, and decrease of cellulose crystallinity, (4) SEM—damaging of cell-walls by micro-cracks, and their degradation by thinning. Connections between changes of the individual characteristics of weathered woods, for example, between the colour (ΔE*, etc.) and the molecular structure (carbonyls, etc.), were also determined. 相似文献
60.
The field cricket (Gryllus bimaculatus) is commonly consumed as food in different parts of the world. This study was performed to characterize the chitosan extracted from crickets and to assess its potential use to the growing functional market. The degree of deacetylation (DA), Fourier-transform infrared spectra, X-ray diffraction patterns, molecular mass, scanning electron microscopy spectra, and color were measured. Cricket chitosan nanoparticles were prepared, and the optimal conditions were identified. The molecular mass of the cricket chitosan was lower than that of commercial chitosan; however, the DA, FTIR, and XRD spectra were similar. The particle size (208.27 ± 3.47 nm), zeta potential (35.72 ± 1.29 mV), and polydispersity index (PDI: 0.27 ± 0.03) of the cricket chitosan NPs were superior to the commercial. Addition of NaCl reduced the cricket chitosan NPs size up to 15.5%. This finding is a novel trial to prove the availability of the insect chitosan with a low molecular mass as an active carrier source. 相似文献