FloatBag选择性神经网络集成及其在人脸检测中的应用

神经网络集成利用多个神经网络对同一个问题进行学习,集成在某输入示例下的输出由构成集成的各神经网络在该示例下的输出共同决定.本文提出利用FloatBag的方法择优选择个体神经网络,进而用平均值的方法组合各个体网络.最后,我们将FloatBag方法应用于多角度人脸检测中.实验证明,这种方法优于一般的神经网络集成方法.     

在PCB中集成光数据流的制造

介绍了在PCB中采用埋入光互连波导形成集成光数据流的技术。     

先进的刚-挠性PCB新材料和积层结构

介绍了具有可弯曲的和可用于HDI板积层的新材料而生产的阶跃式刚-挠性PCB.这种新材料既可用于HDI的积层上,又可以应用刚性HDI的设计规则进行设计和采用刚性PCB生产技术与工艺进行生产.     

对测试库房UPS供电系统接地的方案设计

概述了各种接地制式的低压配电系统,指出它们的应用范围。根据测试库房实际要求设计合理的接地系统,有效净化了UPS的供电环境,提高了供电的安全性。     

磁引信应用中的壳体屏蔽效应分析

针对磁引信在应用中遇到的壳体屏蔽问题,提出将引信体近似为回转椭球壳体模型,从理论上详细地分析了椭球壳体在均匀磁场中的屏蔽效应,给出了相应的屏蔽系数公式;并通过试验验证了理论分析的正确性.该研究分析对磁引信体的选材、结构设计及所测得的磁信号处理都有重要的意义.     

Estimation of time-varying connectivity patterns through the use of an adaptive directed transfer function

Frequency-derived identification of the propagation of information between brain regions has quickly become a popular area in the neurosciences. Of the various techniques used to study the propagation of activation within the central nervous system, the directed transfer function (DTF) has been well used to explore the functional connectivity during a variety of brain states and pathological conditions. However, the DTF method assumes the stationarity of the neural electrical signals and the time invariance of the connectivity among different channels over the investigated time window. Such assumptions may not be valid in the abnormal brain signals such as seizures and interictal spikes in epilepsy patients. In the present study, we have developed an adaptive DTF (ADTF) method through the use of a multivariate adaptive autoregressive model to study the time-variant propagation of seizures and interictal spikes in simulated electrocorticogram (ECoG) networks. The time-variant connectivity reconstruction is achieved by the Kalman filter algorithm, which can incorporate time-varying state equations. We study the performance of the proposed method through simulations with various propagation models using either sample seizures or interictal spikes as the source waveform. The present results suggest that the new ADTF method correctly captures the temporal dynamics of the propagation models, while the DTF method cannot, and even returns erroneous results in some cases. The present ADTF method was tested in real epileptiform ECoG data from an epilepsy patient, and the ADTF results are consistent with the clinical assessments performed by neurologists.      

Wavelength shift in vertical cavity laser arrays on a patternedsubstrate

The authors demonstrate a spatially chirped emission wavelength in vertical cavity surface emitting laser (VCSEL) arrays grown by molecular beam epitaxy. The wavelength shift is due to a lateral thickness variation in the Al_0.2Ga_0.8As cavity, which is induced by a substrate temperature profile during growth. A 20 nm shift in lasing wavelength is obtained in a VCSEL array     

Path Loss Models for Low-Height Mobiles in Forest and Urban

This paper presents path loss measurements at 2.1 GHz in forest and urban areas. Empirical path loss models have been presented for low-height dual-mobility channels. Three test scenarios are considered for the transmitter (Tx) and receiver (Rx) placed inside the test vehicle or on a test cart pushed at walking speed. Based on measurements, the in-leaf and single-slope path loss models are presented. The path loss exponents for the dual-mobility channels are found to be between 2.1 and 3.4 in urban and 8.0 in forest, with higher reference when antennas are placed inside the vehicle.     

基于空间矢量算法的双电机高可靠大功率伺服机构研究

在永磁同步电机的空间矢量控制原理的基础上,阐述了一种双电机大功率伺服系统的控制算法及其实现;采用Simulink建立双电机控制的电流、速度、位置的三闭环模型,并利用2台1.5k W级别的样机进行试验。试验结果证明,该控制算法的正确、有效。     

Scanning and Address Allocation Delays in Vehicular Communications

WLAN-based roadside-to-vehicle communications is an increasingly popular research trend. This paper examines the applicability of WLANs in the Intelligent Transportation Systems with focus on reducing the scanning phase delay and the address allocation delay. The handover delays become intolerable when the indoor WLAN Access Poins are accessed from by the outdoor mobile nodes at vehicular speeds. In this work, we propose a baseline scheme which calls for passively scanning only the orthogonal channels to reduce the scanning phase delay in the overall handover latency. We argue that the interference free orthogonal channels are ideal for conveying time critical information in vehicular environments. Secondly, this paper evaluates the delays incurred by the Dynamic Host Configuration Protocol (DHCP) in the handover process. The focus on establishing the amount of delay contributed by each DHCP phase and make some meaningful comments at the end. The conclusions made in this paper are based on real-world experiments and tests.