基于多级BP神经网络的EIT阻抗变化位置的确定

Electrical impedance tomography (EIT) is a new computer tomography technology, which reconstructs an impedance (resistivity, conductivity) distribution, or change of impedance, by making voltage and current measurements on the object's periphery. Image reconstruction in EIT is an ill-posed, non-linear inverse problem. A method for finding the place of impedance change in EIT is proposed in this paper, in which a multilevel BP neural network (MBPNN) is used to express the non-linear relation between the     

Promoting the social inclusion and academic progress of Gypsy,Roma and Traveller children: a secondary school case study

The aim of this study was to identify support strategies used to promote “social inclusion” and “academic progress” of Key Stage 3 and 4 Gypsy, Roma and Traveller (GRT) pupils. The study used an interpretivist approach, incorporating an embedded single case study with several participant groups, namely GRT pupils, GRT parents, school staff and supporting professionals. The data were collected using interviews, focus groups and questionnaires and were analysed using explanation building – a pattern matching technique which uses theoretical propositions (generated from existing research) to guide analysis and organise data. The study identified one consistent strategy (focussed staff support) to promote both the social inclusion and the academic progress of GRT pupils, and several additional strategies to address each of these areas. The focussed staff support consisted of a dedicated staff member employed to support GRT pupils and families, and act as a consultant for other members of school staff.     

Multi-sensor image registration using multi-resolution shape analysis

INTRODUCTION Image registration plays an important role in the fusion of remote sensing, video panorama, medical image processing, etc. (Li et al., 1995; 2004; Brown, 1992; Belongie et al., 2001; Rui et al., 2001). More different than video panorama, the registration of multi-sensor image needs to align the multi-sensor images of the same scene from different sources (Rignot et al., 1991). Multi-sensor image registration is widely used in the fusion of panchromatic images with infrared i…     

一种基于稳定分配理论的一档多投撮合算法

一档多投是新一轮高考招生制度改革探索的新模式,关系到广大考生的切身利益。研究了盖尔-沙普利稳定匹配理论算法,将算法应用于一档多投的志愿和高校招生计划撮合匹配。实验结果表明,采用盖尔-沙普利算法匹配的录取结果,考生被志愿号靠前的院校和专业录取的概率高,院校完成招生计划情况好,兼顾了考生和招生院校双方的利益。     

Effects of kindergarten retention for at-risk children’s psychosocial development

Kindergarten retention is a popular practice for children who are considered unready for primary school. However, past research has not yet succeeded to find consistent, strong empirical evidence supporting the practice. In the current study, kindergarten repeaters’ development in nine psychosocial domains is compared with that of equally at risk but (1) continuously promoted age-mates and (2) promoted age-mates who repeated first grade instead. Analysing data from a large-scale longitudinal study using propensity score matching and multilevel modelling, the findings reveal no harm of kindergarten retention for at-risk children’s long term psychosocial development. Rather, we find that, relative to equally at-risk but continuously promoted children, kindergarten repeaters benefit from retention with respect to higher levels of well-being, and peer relations, and lower levels of hyperactivity, aggression and asocial behaviour. Compared to similar children who were promoted but who were retained in first grade instead, kindergarten repeaters are found to benefit more from retention with respect to higher levels of well-being, self-confidence, attitude to work and independent behaviour, and lower levels of hyperactivity.     

Adapting mentoring to individual differences in novice teacher learning: the mentor’s viewpoint

Being adaptive to the individual novice teacher is considered a condition for effective teacher mentoring. The aims of this study are therefore to explore (1) mentoring activities through which mentors intend to adapt to the individual novice teacher and (2) characteristics of adaptive mentors. Information was collected through on-site, post-mentoring conversation interviews with 18 mentors holding different mentoring conceptions, from different programs for Initial Teacher Education in the Netherlands. Four adaptive mentoring activities were identified: (1) aligning mutual expectations about the mentoring process, (2) attuning to the novices’ emotional state, (3) adapting the mentoring conversation to match the reflective capacity of the novice teacher, and (4) building tasks from simple to complex relative to the novices’ competence level. Adaptive mentors were (1) more likely to mention activities intended to support construction of personal practical knowledge and (2) less likely to mention activities intended to create a favourable context for novice teacher learning. Suggestions for using findings to enhance mentor adaptiveness are discussed.     

Im U CP 形图的匹配等价

完整刻画了Im U Cp （p≥6为偶数或素数且p≠m-3）及其补图的匹配等价图.     

卤化亚汞声光器件换能器电输入阻抗

利用压电换能器等效电路网络分析法,计算了以环氧树脂为缓冲层(粘接层)的x-cutLN/卤化亚汞声光器件中换能器三层结构规一化电输入阻抗|Zj|随规一化频率f/f0的变化值,绘出了|Zj|-f/f0关系立体图。得出器件的输入阻抗是射频频率复杂的复数函数及在不同频率段分别呈现感抗和容抗特性且随电极层厚度变化而变化的结论。     

电导率、温度对电阻抗法测量红细胞流变特性的影响

目的:本文着重研究用电阻抗法测量红细胞松弛过程时,悬浮介质电导率和温度对其的影响。方法:利用红细胞流变特性自动测定仪,对具有相同粘度,但电导率、温度不同的样品进行测量。结果:当悬浮介质的电导率在8～300us/cm范围内对红细胞流变特性的测量虽有影响,但关系不大。在电导率为25～260us/cm范围内所测的最大变形值与均值59.34的相对误差不超过1.1％。而温度变化引起的测量误差也均在此范围之内,结论:当选用右旋醣酐DX_(70)配制的红细胞悬浮液(电导率70～150us/cm之间)在室温(20±5)℃下,用该仪器进行测量时,其介质的电导率和温度变化所造成的测量误差是可以忽略不计的。     

Book matters: The effect of Cocky’s Reading Express on student performance

The literature argues that children are more likely to succeed academically if they acquire strong reading skills and a love of reading at a young age. In this paper, I evaluate an early childhood literacy program, Cocky’s Reading Express (CRE), to understand how reading events at school and the gifts of books impact learning. Combining the CRE visit records with administrative student data, I find that CRE leads to 0.02–0.03 of a standard deviation increase in statewide English Language Arts test scores among low-income students one year after the visit and find suggestive evidence that CRE improves the math scores for subgroups of students in poverty. In particular, the CRE effect varies based on locality and access to reading materials, with a larger effect on students residing in metropolitan areas or close to public libraries. However, the positive effects on low-income students diminish over time; CRE does not show impacts on the scores of students from better-off families either.