基于线检测器的红外弱小目标检测

复杂背景下低信噪比弱小目标的检测仍然是当今的一个难题,尤其是在复杂背景的抑制方面,针对红外小目标的特点,以及红外小目标实时性检测的要求,提出了一种检测低信噪比的复杂背景情况下的红外图像点目标的新的算法。首先,用一个线检测器,对红外图像进行处理,经过其处理后的图像,不仅可以大幅度抑制背景,而且还能增强目标,极大程度的提高了图像的信噪比;其次,对处理后的图像用二维的Otsu自动阈值分割法进行分割,检测出点目标。通过对红外图像的实验,证明该算法的有效性。

一种智能化网线检测器的设计

网线在组网的过程中尤为重要,文章设计出一款经济实用的网线检测器,并精要地分析了其工作原理.

包装生产线断线检测系统的设计与应用

由于没有断线检测系统 ,乙烯成品车间包装缝合系统频繁洒料、停机 ,给生产造成巨大浪费。通过技术改造 ,采用断线检测器 ,并在包装机控制系统中编制运行程序 ,解决了这一生产难题。

DS/SS信号检测与估计的性能

直接序列扩频信号 (DS/SS)广泛应用于卫星通信等领域 ,由于它的信噪比往往很低 ,给电子侦察带来了很大的困难。结合目前的研究进展 ,综述了用于直扩信号检测和估计的几种主要方法 ,简要阐述了它们的特点和适用性 。

线上线下结合的实时手势跟踪系统

手势识别跟踪一般采用线下训练分类器,不能有效检测跟踪形变的手势,针对手势形变及在窗口的暂时性消失等问题,提出了一种通过线下训练结合线上提取样本对分类器进行训练的检测方法,同时采用跟踪-检测-学习(TLD)的方法不断对跟踪器的结果进行纠正。试验结果表明,本算法对手势形变、短暂消失具有很好的适应性,与TLD算法相比较具有更好的稳定性。

电子线路应用实例及其技法(一)

超低音滤波器扩展低音频响在封闭式音箱中的扬声器频率响应是一只二阶高通滤波器的响应,而截止频率及Q值很容易由音箱尺寸确定。通过滤波器及功率放大器馈给扬声器信号,在该扬声器谐振频率以下却产生平直的响应,从而构成一个简单但却十分有效的超低音音箱。

基于不同尺度增强融合的视网膜血管分割算法

针对现有视网膜血管图像提取细小血管准确率较低的问题,提出了一种基于多尺度线性检测器与局部和全局增强相结合的视网膜血管分割方法。对多尺度线检测器进行研究,将其分为小尺度和大尺度两部分;利用小尺度对局部增强后的图像与大尺度对全局增强后的图像分别进行检测,得到不同尺度下的响应函数;将不同尺度下的响应函数进行融合,得到最终的视网膜血管结构。在STARE和DRIVE两个数据库上进行实验,结果表明:该算法得到的平均血管准确率分别达到96.62%和96.45%,平均真阳性率分别达到75.52%和83.07%,分割准确率高,能够得到较好的血管分割结果。

一种用于土壤非金属养分测试的光纤探头式分光光度计

针对测土配方施肥技术中要求快速、便捷、高效地进行土壤养分测试的需求,文章基于浸入式光纤探头、平场凹面全息光栅、二极管线阵检测器开发了一种光纤探头式分光光度计用于土壤养分中非金属元素的快速、准确测试。基于国家计量检定规程JJG 178—2007对紫外、可见、近红外分光光度计的性能检测方法测试的该仪器的波长最大允许误差与波长重复性、基线平直度、透射比最大允许误差与透射比重复性均达到了国标第Ⅲ级别标准,其最小光谱带宽、噪声与漂移、杂散光基本达到了国标第Ⅳ级别标准。基于该仪器测试的土壤硝态氮、铵态氮、有效磷、有效硫、有效硼、和有机质含量与基于商用的国产单光束和进口双光束分光光度计测试的结果呈极显著的线性相关关系,其回归方程的斜率接近于1,且对比数据之间无显著性差异。因此,该光纤探头式分光光度计可用于土壤非金属养分的快速、准确测试。

基于SVM的眼底血管分割技术

针对眼底中小血管提取的问题,提出了一种基于支持向量机的眼底血管分割方法。首先,采用高斯匹配滤波器对眼底图像进行滤波,增强图像对比度;然后,为了加快滤波器的运算速度,提出一种改进的滤波方法,只需像素与最佳匹配模板做卷积;最后,为了提高算法的分类性能,采用均值漂移算法先对滤波后的图像预分类。仿真结果表明提出方法能更准确地分割出眼底血管网络,特别是对中小血管的分割更加精确。

Traffic light detection and recognition in intersections based on intelligent vehicle

To ensure revulsive driving of intelligent vehicles at intersections, a method is presented to detect and recognize the traffic lights. First, the stabling siding at intersections is detected by applying Hough transformation. Then, the colors of traffic lights are detected with color space transformation. Finally, self-associative memory is used to recognize the countdown characters of the traffic lights. Test results at 20 real intersections show that the ratio of correct stabling siding recognition reaches up to 90%;and the ratios of recognition of traffic lights and divided characters are 85% and 97%, respectively. The research proves that the method is efficient for the detection of stabling siding and is robust enough to recognize the characters from images with noise and broken edges.

Coordinate-free k-coverage hole detection algorithm in wireless sensor networks

For wireless sensor networks, a simple and accurate coordinate-free k-coverage hole detection scheme is proposed. First, an algorithm is presented to detect boundary cycles of 1-coverage holes. The algorithm consists of two components, named boundary edge detection and boundary cycle detection. Then, the 1-coverage hole detection algorithm is extended to k-coverage hole scenarios. A coverage degree reduction scheme is proposed to find an independent covering set of nodes in the covered region of the target field and to reduce the coverage degree by one through sleeping those nodes. Repeat the 1-coverage hole detection algorithm and the higher order of coverage holes can be found. By iterating the above steps for k-1 times, the boundary edges and boundary cycles of all k-coverage holes can be discovered. Finally, the proposed algorithm is compared with a location-based coverage hole detection algorithm. Simulation results indicate that the proposed algorithm can accurately detect over 99% coverage holes.

Design of intelligent line-tracking chess robot based on STM32

An intelligent line-tracking chess robot based on STM32 is introduced in this paper. Its hardware consists of photo- electric detection circuit, main control circuit, motor driven circuit, steering engine driven circuit and dial switch. The hardware structure and software flow chart of the system are described in details in this paper. The robot is driven by rear wheel motors, and the real-time position of the robot is determined by the ground information collected by infrared sensors. The heading direction of robot is adjusted by steering engine installed in front wheel, and the open angle of manipulator is controlled by the other steering engine which can ensure the robot moving chessmen accurately and quickly during the moving process. The test shows that the kind of intelligent chess robot can complete the task in a fast and accurate way.

Determination of Threshold for Energy Detection in Cognitive Radio Sensor Networks

The Internet of Things （loT） is called the world＇ s third wave of the information industry. As the core technology of IoT, Cognitive Radio Sensor Networks （CRSN） technology can improve spectrum utilization efficiency and lay a sofid foundation for large-scale application of IoT. Reliable spectrum sensing is a crucial task of the CR. For energy de- tection, threshold will determine the probability of detection （Pd） and the probability of false alarm Pf at the same time. While the threshold increases, Pd and Pf will both decrease. In this paper we focus on the maximum of the difference of Pd and Pf, and try to find out how to determine the threshold with this precondition. Simulation results show that the proposed method can effectively approach the ideal optimal result.

A NEW RECURSIVE ALGORITHM FOR MULTIUSER DETECTION

Based on the synthesis and analysis of recursive receivers, a new algorithm, namely partial grouping maximization likelihood algorithm, is proposed to achieve satisfactory performance with moderate computational complexity.During the analysis, some interesting properties shared by the proposed procedures are described.Finally, the performance assessment shows that the new scheme is superior to the linear detector and ordinary grouping algorithm, and achieves a bit-error rate close to that of the optimum receiver.

Determination of 5-Fluorouracil in Human Plasma by High-Performance Liquid Chromatography (HPLC)

5-Fluorouracil (5-FU) has a broad spectrum of anti-tumor activity, widely applied to the treatment of cancers. However, it is necessary to determine the plasma concentration of 5-FU in clinical practice due to its narrow therapeutic index. Therefore, a simple, economic and sensitive high-performance liquid chromatography (HPLC) method was developed and validated for the determination of 5-FU in human plasma. Ethyl acetate was chosen as extraction reagent. Chromatographic separation was performed on a Diamonsil C18 column (250 mm × 4.6 mm i.d., 5 μm) with the mobile phase consisting of methanol and 20 mmol/L ammonium formate using a linear gradient elution at a flow rate of 0.8 mL/min. 5-FU and 5-bromouracil (5-BU) were detected by UV detector at 265 nm. The calibration curve was linear over the concentration range of 5—500 ng/mL and the correlation coefficient was not less than 0.992 6 for all calibration curves. The intra- and inter-day precisions were less than 10.5% and 4.3%, respectively, and the accuracy was within ±3.7%. The recovery at all concentration levels was 80.1±8.6%. 5-FU was stable under possible conditions of storing and handling. This method is proved applicable to therapeutic drug monitoring and pharmacokinetic studies of 5-FU in human.

Efficient Algorithm for K-Barrier Coverage Based on Integer Linear Programming

Barrier coverage of wireless sensor networks is an important issue in the detection of intruders who are attempting to cross a region of interest.However,in certain applications,barrier coverage cannot be satisfied after random deployment.In this paper,we study how mobile sensors can be efficiently relocated to achieve k-barrier coverage.In particular,two problems are studied:relocation of sensors with minimum number of mobile sensors and formation of k-barrier coverage with minimum energy cost.These two problems were formulated as 0–1 integer linear programming(ILP).The formulation is computationally intractable because of integrality and complicated constraints.Therefore,we relax the integrality and complicated constraints of the formulation and construct a special model known as RELAX-RSMN with a totally unimodular constraint coefficient matrix to solve the relaxed 0–1 ILP rapidly through linear programming.Theoretical analysis and simulation were performed to verify the effectiveness of our approach.

A Group-Based Fingerprinting Scheme for Digital Wholesale and Retail

Prior group-based fingerprinting achieves better detection performance when colluders are from the same group. But in digital wholesale and needs to be identified retail, the middleman as well as customers especially against group colluding attack. The group tracing is neglected in previous works. In this paper, we propose a novel multimedia group fingerprint to trace malicious middlemen along with customers. We explore the quality of the non degenerate linear shift register sequence （NDLSRS） which is convenient in group initialization and management. The theoretic analysis and simulation experiment results show that NDLSRS has good resistance against attacks from colluding groups/ members even after its volume expanded.

Wireless Transmission System for Vehicle Inspection Data

Based on general packet radio service(GPRS) and TCP/IP protocol,a wireless transmission system of vehicle inspection data is designed. Basic structure and work theory are expounded. SIM300 designed by SIMCOM is used for client GPRS communication module. Using Winsock control of visual basic(VB),the client and server communication has been accomplished. By means of a client and server communications software,the remote wireless transmission of vehicle inspection data has been accomplished also. The server management software has been developed by using Microsoft SQL Server 2000 and VB6.0. Functions of software include import,inquiry,export and maintenance of test data.

Behavior analysis of malicious sensor nodes based on optimal response dynamics

Wireless sensor networks are extremely vulnerable to various security threats.The intrusion detection method based on game theory can effectively balance the detection rate and energy consumption of the system.The accurate analysis of the attack behavior of malicious sensor nodes can help to configure intrusion detection system,reduce unnecessary system consumption and improve detection efficiency.However,the completely rational assumption of the traditional game model will cause the established model to be inconsistent with the actual attack and defense scenario.In order to formulate a reasonable and effective intrusion detection strategy,we introduce evolutionary game theory to establish an attack evolution game model based on optimal response dynamics,and then analyze the attack behavior of malicious sensor nodes.Theoretical analysis and simulation results show that the evolution trend of attacks is closely related to the number of malicious sensors in the network and the initial state of the strategy,and the attacker can set the initial strategy so that all malicious sensor nodes will eventually launch attacks.Our work is of great significance to guide the development of defense strategies for intrusion detection systems.

LMI Approach to Mixed H_/H_∞ Fault Detection Observer Design

To investigate the robust fault detection （RFD） observer design for linear uncertain systems, the H_index and H∞ norm are used to describe this observer design as optimization problems. Conditions for the existence of such a fault detection observer are given in terms of matrix inequalities. The solution is obtained by new iterative linear matrix inequality （ILMI） algorithms. The RFD observer design over finite frequency range in which Of does not have full column rank for a system is also considered. Numerical example demonstrates that the designed fault detection observer has high sensitivity to the fault and strong robustness to the unknown input.