嵌入CBAM结构的改进YOLOV3超宽带雷达生命信号检测算法

为了提高超宽带雷达生命信号检测准确率,提出了一种改进型YOLOV3检测算法。考虑到超宽带雷达探测的人体呼吸信号成像后宽高相差较大,采用多尺度训练时网络对宽高的敏感程度不一样,因此在设计损失函数时,对宽高损失给予不同的权重系数。为了提高网络通道以及空间特征表达能力,使得网络能够扩大对目标特征区域的感知范围,因此将通道注意力与空间注意力结构(CBAM)嵌入到YOLOV3基础网络Darknet53的每个shortcut层,得到CBAM-YOLOV3网络结构。对比改进前后的算法。实验结果表明,改进后的算法在IoU阈值为0.5时,mAP为98.09%,提升3.90%,在阈值为0.75时,mAP为76.49%,提升16.48%。     

纤维的结构和性能（Ⅲ）

本文介绍了ＰＥＴ高速纺丝纤维的热性能，低速纺丝领域中纤维的大分子取向以及纤维结晶相和非结晶相的取向，指出：纤维的沸水收缩率在纺速为２０００－３０００ｍ／ｍｉｎ内达最大值，其后随纺速增加急剧减少；纤维结晶相取向度随纺增加而增大；非晶向取向在６００ｍ／ｍｉｎ纺速以随纺速增加而增大，６０００ｍ／ｍｉｎ纺速以上随纺增加而减少。另外指出纺丝速度在７０００ｍ／ｍｉｎ以上时，ＰＥＴ纤维横断面上存在一个内部结构分     

Electrochemical and ellipsometric study of the oxide films formed on copper in borax solution: Part I: Effect of oxygen

The formation and reduction of passive layers on copper in weakly alkaline solutions saturated with N2 and O2 were studied. Voltammetric and ellipsometric techniques were employed to examine the structural characteristics of the layers formed in the –0.32 to 0.75 V vs RHE potential region. Optical measurements at open circuit potentials (Eoc) were also made to simulate operational conditions. The passive layer consists of a duplex structure: an outer hydrated copper oxide film and an inner dehydrated film. This inner layer is composed of Cu2O with a surface excess of Cu(ii) ions. The growth rate of the oxide layers at controlled potentials is higher in O2 saturated solution. The corrosion resistance of copper depends on the presence of O2 in the electrolyte, on the stirring rate and on the Eoc value.     

END-WINDING INFLUENCE ON HOMOPOLAR EFFECTS IN ASYMMETRICAL THREE-PHASE MACHINE WINDINGS

ABSTRACT

Asymmetries in three-phase windings of rotating-field a.c, machines may cause homopolar currents in delta-connected phase windings. End-winding particulars can have an Important quantitative influence on these currents and on the connected phase current inequalities.     

ROTOR RESISTANCE ESTIMATION FOR SLIP ADAPTATION IN SENSORLESS INDUCTION MACHINE DRIVES

ABSTRACT

This work presents a rotor resistance estimation algorithm. The estimation process is based on a recursive least squares method. It is applied to a speed sensorless induction motor drive scheme in order to implement slip adaptation. A discrete approach is considered in which an induction motor model written in form of difference equations is used by the estimation algorithm. All the associated mathematical developments are shown. Simulation results are used to verify the performance of the proposed rotor resistance estimator.     

Some results on the improvement of adaptation transients

A technique to improve the adaptation transient in discrete-time model reference adaptive control (MRAC) systems is given on the basis of applying classical optimization techniques to an equivalent near-linear system to the whole adaptive scheme. The resulting optimization is finally translated into modifications of one of the parameters entering the adaptation algorithm. This permits computation of a posteriori values of the adaptive controller parameters before generation of the input to the plant.     

VHF propagation characterization during atmospheric disturbances

Abstract

The propagation of a television (TV) signal is usually perturbed during periods of atmospheric disturbance such as in thunderstorms. The region under investigation here is situated in the coastal area of the Bay of Bengal and has experienced frequent thunderstorm activities. An investigation to study their effects on VHF signal propagation transmitted from Satkhira in Bangladesh and received at the Indian Statistical Institute, Calcutta, has been undertaken. The depths of the atmospheric disturbances within a 1?km range have been recorded and measured by acoustic sounder (sodar) operated continuously at the receiving station. The inset of the storm is marked by the enhanced signal level with deep fluctuations characteristic during the periods of thunderstorms.     

温度测控技术在中药加速仪中的应用

本文介绍了中药加速仪利用单片机和热敏电阻设计低成本温度测控系统的一种温度测量比值查表方法和温度脉冲加热控制法,并对硬件系统原理和软件设计流程作了简要描述。     

Evaluation of the role of waste in a truck manufacturing line using simulation

In their never-ending search to improve manufacturing performance, companies try to eliminate all sources of waste. In this paper, we describe how the effects of the elimination of waste on performance measures such as lead time and overtime costs can be estimated using logistical simulation. This is illustrated using a real-life case study that was conducted in the repair department of a truck cabin factory. In this department, cabs are controlled and if necessary repaired. The first part of the paper describes how bottlenecks were determined for both the present layout and for a proposed layout change. This turned out to be difficult, as several product flows intertwine. Modelling was made complex by these interactions, as they caused deadlock phenomena. The second part of the paper represents a sensitivity analysis, which evaluates the effects of different types of waste, such as machine breakdowns, inadequate buffer size and production time variance.     

网管日记

今天老板让我把网吧里的CS全删除了,我忙活了一晚上.至于为什么要删除CS呢?其实起因是这样的.今天公安局的临时检查,之前已经得到过风声,一连几天我都当了清道夫,把18岁以下的任何生物统统赶出了网吧.所以远远的看着警察叔叔们来时,我和老板都没什么紧张的.