双支持向量回归的牛顿算法

为提高支持向量回归的运算速度,提出一种双支持向量回归的牛顿算法。求解2个只带一组约束的支持向量问题,以减少运算量,将2个约束优化问题转化为无约束最优化问题,并采用牛顿迭代算法求解。实验结果表明,在保证与支持向量回归和双支持向量回归拟合能力相当的同时,该算法能减少训练时间。     

Biogeography based hybrid scheme for automatic detection of epileptic seizures from EEG signatures

Biogeography Based Optimization (BBO) algorithm is one of the nature-inspired optimization methods, based on the study of geographical distribution of species on earth. The present research work is based upon decomposition of human electroencephalograms (EEG) signal by Wavelet Packet Transform, computation of a complete feature set using statistical and non-statistical properties followed by optimal selection of features by BBO; the optimality criterion being classification rate. The stopping criterion for BBO is set to 100% correct classification rate. The proposed algorithm is novel in terms of TWSVM computing the Habitat Suitability Index (HSI) values for BBO, perfect classification rate, low computation time, and feature selection mechanism. The proposed scheme outperforms several previous results reported in literature in that it gives a feature subset which gives 100% classification accuracy for different classification instances.     

Mathematical modeling of melting rate in twin-wire welding

The paper treats four mathematical models for calculation of melting rate in arc fusion welding with a wire in coil form. The mathematical models permit calculation of melting rate in direct current welding with single-wire and double-wire electrodes (both polarities).

For single-wire welding the models treated have been improved with regard to the ones published in the literature, for twin-wire welding, these are the first models for calculation of melting rate. The mathematical models have already been tested in practice and the results obtained show that they are very accurate, simple and applicable to practice.     

三旋单管末端形状研究

在旋风分离单管末端常采用直锥结构来提高分离效率，然而实际使用过程中常常发现在直锥的上部存在“下灰环”，对单管局部造成严重磨损，对整个装置的安全运行构成极大威胁。下灰环的形成主要是由于单管末端收缩曲线不光滑造成的。为了验证这个假设，选择了航空风洞收缩段常用的双三次方曲线作为单管末端收缩曲线，制成所谓双三次方锥并且做了流场显示实验。实验结果初步证实了这个假设     

基于数字孪生的山岭地区高速公路施工进度管理研究

本研究将数字孪生技术引入高速公路施工进度管理,提出了利用BIM参数化建模和实景建模技术构建山岭地区高速公路数字孪生模型的方法,设计了基于蓝牙技术、GPS技术及ZigBee技术的数据采集和映射方案,并在此基础上构建了基于数字孪生的进度推演模型。本文以雷榕高速公路工程项目为依托,利用数字孪生模型和数据采集技术实时获取现场工程量和进度影响信息数据,通过数据驱动的方式构建进度推演模型,使施工过程中的进度安排、资源配置更加合理,减少由于工期延误造成的成本问题或赶工引发的质量问题。     

双能量X射线荧光全息图重构算法消除孪生像的模拟研究

X射线荧光全息术以样品内部的发光原子作为相干光源进行全息成像,可以直接观测到晶体内部原子的三维排列结构.和传统的全息术一样,X射线荧光全息术也遇到了孪生像问题.本文以27个Fe原子成立方排列的结构为模型,采用双能量荧光全息图重构算法研究入射X射线能量的选取对消除孪生像效果的影响.结果表明:记录荧光全息图的两个X射线能量越接近(对于内探测器全息术而言,最小能量差取决于单色器和探测器的能量分辨率;对于内源全息术而言,最小的能量差取决于元素的两个紧邻荧光能量差和探测器的能量分辨率),消除孪生像的效果越好;而入射X射线的能量越高,则原子像的分辨率越高.     

Terex launches 3,200t CC8800-1 Twin

Terex-Demag of-ficially handed overthe first of its uniqueand very high capacityCC8800-1 Twin crawlercranes to Al Jaber HeavyLift, at a ceremony inZweibrücken(1).     

The Danish Twin Apartment Study; Part I: Formaldehyde and Long-Term VOC Measurements

Field measurements of 21 volatile organic compounds (VOC) using diffusive samplers, formaldehyde, temperature, and humidity were performed from the time of building completion throughout the following one-year period in two new semi-detached twin apartments. One of these was occupied after six weeks. Headspace analyses from all building materials and products showed 120 different VOC. Formaldehyde concentrations were strongly seasonally dependent in the vacant apartment and increased to above 400 μg/m³ during the warm season. The formaldehyde concentration generally decreased in the occupied apartment but increased again during the fall season. VOC originating from building materials generally showed a decrease in emission, but strong seasonal variations were observed. It was shown that human activity introduces several VOC to the indoor environment. Storage of motorcycle parts in the crawl space of the occupied apartment resulted in migration and an infiltration of benzene and toluene into the apartment above and probably to a delayed peak concentration in the twin vacant apartment. Similarly, large VOC increases in one apartment were reflected by a later increase of the same VOC in the twin apartment. Hexanal increased during the warm season. TVOC, as the sum of 21 VOC, was generally approximately 50 % higher in the occupied apartment during the cold season. The results indicate the difficulties in interpreting long-term measurements. The “flushing period” recommended for this type of building has been estimated to be about 130 days.     

温度场对iPP/CAB体系形态结构的影响

利用扫描电子显微镜研究了温度场对iPP/CAB共混物样品形态结构的影响,研究发现共混物样品在150℃的硅油或者140℃的真空烘箱中放置时,随着热处理时间的增加,分散相尺寸会不断增大;并且样品在硅油中放置时,分散相尺寸增大的速度更快.