Academic attainment in students with autism spectrum disorders in distance education

This investigation studied attainment in students with autism spectrum disorders (ASDs) who were taking modules by distance learning with the UK Open University in 2012. Students with ASDs who had no additional disabilities were as likely as non-disabled students to complete the modules that they had taken, to pass the modules that they had completed and to obtain good grades for the modules that they had passed. Students with ASDs who had additional disabilities were less likely than non-disabled students to complete the modules that they had taken, but they were as likely as non-disabled students to pass the modules that they had completed and to obtain good grades for the modules that they had passed. Their lower completion rate presumably reflects the impact of their additional disabilities rather than their ASDs. In distance education, at least, students with ASDs tend to perform on a par with their non-disabled peers.     

Post-primary school teachers’ knowledge and understanding of autism spectrum disorders

Current national policy in the Republic of Ireland advocates for the inclusion of students with learning difficulties in mainstream schools. With Asperger’s syndrome (AS) specifically, it is essential that teachers understand the syndrome and are well versed in appropriate approaches to effectively create an inclusive environment for these students in the mainstream classroom. This paper explores teacher knowledge and understanding of AS while also exploring what affects their confidence in educating students diagnosed with the syndrome. Data collection pre-dated changes to the DSM-V and as such AS is used throughout this paper. A survey was distributed nationally to a random sample of qualified post-primary school teachers. The findings revealed that teachers did not appear to possess an adequate level of knowledge and understanding in relation to the syndrome. Continued professional development programmes in the area appeared to have minimal effect, with those completing programmes scoring only marginally better than those who did not (2.85%). These findings are of concern if these teachers are then expected to foster an inclusive environment, particularly when a high proportion of teachers have previously taught a student diagnosed with the syndrome and their knowledge remains limited.     

Interference cancellation scheme for uplink cognitive radio systems

This paper investigates the interference cancellation (IC) scheme for uplink cognitive radio systems, using the spectrum underlay strategy where the primary users (PUs) and the secondary users (SUs) coexist and operate in the same spectrum. Joint MMSE-based parallel interference cancellation (PIC) and Turbo decoding scheme is proposed to reduce the interference to the PUs, as well as to the SUs, in which the minimum mean square estimation (MMSE) filter is only employed in the first iteration, regarded as the “weakest link” of the whole detection process, to improve the quality of the preliminary detections results before they are fed to the Turbo decoder. Simulation results show that the proposed scheme can efficiently eliminate the interference to the PUs, as well as to the SUs.     

高压下β硼电输运行为中的晶界效应

利用交流阻抗谱方法,讨论了高压下晶界效应对β硼电输运性质的影响,最高压力为28.3GPa.结果表明：晶粒电阻和晶界电阻均随压力逐渐减小;晶界电阻对总电阻的贡献随压力逐渐减小,当压力达23.9GPa时,随着范德瓦尔斯力及晶界相互作用的出现,晶界传导几乎消失.     

Time-frequency channel modeling and estimation of multi-carrier spread spectrum communication systems

In wireless communications, the channel is typically modeled as a random, linear, time-varying system that spreads the transmitted signal in both time and frequency due to multi-path propagation and Doppler effects. Estimated channel parameters allow system designers to develop coherent receivers that increase the system performance. In this paper, we show how time-frequency analysis can be used to model and estimate the time-varying channel of a multi-carrier spread spectrum (MCSS) system using a complex quadratic sequence as the spreading code. We will show that for this spreading code, the effects of time delays and Doppler frequency shifts, caused by the mobility of environment objects, can be combined and represented effectively as time shifts. The discrete evolutionary transform (DET), as a time-frequency analysis method, enables us to estimate the effective time shifts via a spreading function and to use them to equalize the channel. Using the effective time shifts, the time-varying channel can be represented simply as linear-time invariant system by embedding the Doppler shifts that characterize the time-varying channel into effective time shifts. The channel parameters are used to estimate the data bit sent. To illustrate the performance of the proposed method we perform several simulations with different levels of channel noise, jammer interference, and Doppler frequency shifts.     

Performance analysis of a spreading sequence estimator for spread spectrum transmissions

Direct sequence spread spectrum transmissions (DS-SS) are now widely used for secure communications, as well as for multiple access. They have many interesting properties, including low probability of interception. Indeed, DS-SS transmitters use a periodical pseudo-random sequence to modulate the baseband signal before transmission. A receiver which does not know the sequence cannot demodulate the signal.In this paper, we propose a new method which can estimate the spreading sequence in a noncooperative context. The method is based on eigenanalysis techniques. The received signal is divided into windows, from which a covariance matrix is computed. We show that the sequence can be reconstructed from the two first eigenvectors of this matrix, and that useful information, such as desynchronisation time, can be extracted from the eigenvalues.The main achievement of the present paper is a performance analysis of the proposed spreading sequence estimation procedure. An analytical approach is first considered owing to matrix perturbation theory and Wishart matrix properties. Then, complementary Monte Carlo simulations are performed to show the effectiveness of the proposed method.     

激光甲烷传感器及其交叉干扰实验研究

基于激光光谱吸收的原理,研究了激光甲烷传感器的测量原理和系统设计,开展了实验室环境下水汽、一氧化碳和二氧化碳等气体对甲烷测量结果的交叉干扰,给出了实验数据并进行了相关分析。实验证明激光甲烷传感器具有测量准确,稳定性高,抗气体交叉干扰等特性。     

不同产地金钗石斛红外光谱解析

利用傅利叶变换红外光谱仪（Fourier Transform Infrared Spectroscopy）分析了来自云南和浙江的两个金钗石斛（Dendrobium nobile Lindl.）的红外光谱特征。两个金钗石斛样品均具有基本相似的红外光谱,但个别吸收峰的峰强及峰位具有明显区别。云南金钗石斛具有明显的2851 cm^-1吸收峰和较小的1736 cm^-1的吸收峰,而浙江金钗石斛具有较小的2852 cm^-1峰和很强的1740 cm^-1吸收峰,其峰高与1636 cm^-1处的峰高相当。两者的二阶导数谱在1055 cm^-1和1073 cm^-1附近的峰也有明显区别。这种方法对于快速直接判定金钗石斛的产地来说是可行的。     

Raising Autism Awareness among Greek Teachers

A recent special education legislation reform in Greece puts emphasis on the inclusion of pupils with special educational needs into mainstream schools. The purpose of the present study was to investigate knowledge of ASD among 67 mainstream nursery and primary classroom teachers, and evaluate the effectiveness of a half-day ASD awareness seminar in increasing their knowledge of the disorder. A self-report ASD Knowledge Questionnaire (ASD-KQ), developed for the purpose of this study, was used before and after the ASD awareness seminar. The results indicated a significant shift from low to moderate/high level of ASD knowledge among teachers with no previous training in special education and/or autism (58.7%), whereas this shift did not reach significance level in the teacher’s group with previous training (16.7%) after the seminar. The present findings have important implications for the development of training programmes of practising teachers.