期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
基于Gentle Adaboost的多姿态人脸检测器结构研究
1
作者 吴秋岚 金立左 《工业控制计算机》 2017年第8期61-63,共3页
研究在多姿态人脸检测问题中,不同检测器组织结构及其性能差异。只探讨平面外旋转±90°的姿态空间,将其划分为5类姿态。首先训练单姿态检测器,通过提取扩展Haar-like特征,采用Gentle Adaboost算法,训练得到瀑布型检测器;然后... 研究在多姿态人脸检测问题中,不同检测器组织结构及其性能差异。只探讨平面外旋转±90°的姿态空间,将其划分为5类姿态。首先训练单姿态检测器,通过提取扩展Haar-like特征,采用Gentle Adaboost算法,训练得到瀑布型检测器;然后对单姿态检测器进行组合构成多姿态分类器。主要对并行级联结构、并行级联附加姿态估计、金字塔结构和决策树结构4种组合结构进行实验对比,分析其在检测速度、检测率、误检数等性能指标上的差异。 展开更多
关键词 人脸检测 多姿态 检测器结构 GENTLE ADABOOST
下载PDF
微小型氢火焰离子化检测器及在色谱中的应用 被引量:7
2
作者 王建伟 彭虹 +1 位作者 段春凤 关亚风 《分析化学》 SCIE EI CAS CSCD 北大核心 2011年第3期439-442,共4页
构建了一种微小型氢火焰离子化检测器(m-FID)。与传统FID不同,助燃空气从收集极上部侧面导入,沿收集极与检测器壳体之间的缝隙向下流动,以环状气流沿壁流入燃烧室,流向反转后从中空的收集极内流出。火焰喷口位于燃烧腔的正中心轴线上,... 构建了一种微小型氢火焰离子化检测器(m-FID)。与传统FID不同,助燃空气从收集极上部侧面导入,沿收集极与检测器壳体之间的缝隙向下流动,以环状气流沿壁流入燃烧室,流向反转后从中空的收集极内流出。火焰喷口位于燃烧腔的正中心轴线上,该区域助燃气的流动非常稳定,因此噪音电平非常低。采用更高的极化电压以提高离子化效率。对喷口材料及其内径、收集极长度、收集极至喷口的距离等结构参数进行了优化。在最优条件下,极化电压800 V时,检测器的信噪比比极化电压为150 V时提高一个数量级以上,检出限达1×10-12g/s。相对于常规FID,m-FID的气体消耗降低了70%,仅需要氢气和空气两种气体;具有体积小、重量轻、结构简单、灵敏度高、成本低廉等优点,适合作为便携式微型色谱的通用型检测器。 展开更多
关键词 氢火焰离子化检测器 微型化 检测器结构 极化电压
下载PDF
Structural Damage Assessment by an Embedded Fiberoptic Sensor Array and Its ANN Signal Processor
3
作者 ZHAO Tingchao HUANG Shanglian CHEN Weimin(Chongqing University, Chongqing 630044, CHN ) 《Semiconductor Photonics and Technology》 CAS 1996年第3期214-218,共5页
A novel type of two-dimensional damage assessment system for real time monitoring the structural health of composite structure is described. The configuration of the embedded fiberoptic sensor array and the model of t... A novel type of two-dimensional damage assessment system for real time monitoring the structural health of composite structure is described. The configuration of the embedded fiberoptic sensor array and the model of the artificial neural network (ANN) are discussed. The experimental system and results show that the system can monitor a damage of structures with potential application in areas such as space aeronautics, civil engineering, etc. 展开更多
关键词 Damage Assessment Fiber Optic Sensors Neural Networks
下载PDF
Eggshell-inspired membrane—shell strategy for simultaneously improving the sensitivity and detection range of strain sensors 被引量:1
4
作者 Hongwei Li Ziting Tan +6 位作者 Liqian Yuan Jie Li Xiaosong Chen Deyang Ji Kai Zhang Wenping Hu Liqiang Li 《Science China Materials》 SCIE EI CSCD 2021年第3期717-726,共10页
The tradeoff between sensitivity and detection range(maximum and minimum stretchability)is a key limitation in strain sensors;to resolve this,we develop an efficient and novel strategy herein to fabricate a highly sen... The tradeoff between sensitivity and detection range(maximum and minimum stretchability)is a key limitation in strain sensors;to resolve this,we develop an efficient and novel strategy herein to fabricate a highly sensitive and stretchable strain sensor inspired by the membrane-shell structure of poultry eggs.The developed sensor comprises a soft and stretchable surface-grafting polypyrrole(s-PPy)film(acting as the membrane)and a brittle Au film(acting as the shell),wherein both films complement each other at the electrical and mechanical levels.Au forms cracks under strain contributing to its high sensitivity and low detection limit,and s-PPy can bridge Au cracks and increase stretchability which has not been used in strain sensors before.The surface-grafting strategy not only enhances interface adhesion but also tunes the brittle property of native PPy to render it stretchable.Utilizing the synergetic effect of the membrane-shell complementary structure,the strain sensors achieve ultrahigh sensitivity(>10^(7)),large stretchability(100%),and an ultralow detection limit(0.1%),demonstrating significant progress in the field of strain sensors.The membrane-shell(Au/s-PPy)-structured strain sensor can successfully detect finger motion,wrist rotation,airflow fluctuation,and voice vibration;these movements produce strain in the range of subtle to marked deformations.Results evidence the ultrahigh performance and bright application prospects of the developed strain sensors. 展开更多
关键词 strain sensor detection range high sensitivity surface-grafting membrane-shell
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部