On processing GPS tracking data of spatio-temporal car movements: a case study

Abstract

The advancement of GPS technology has made it possible to use GPS devices as orientation and navigation tools, but also as tools to track spatio-temporal information. GPS tracking data can be broadly applied in location-based services, such as spatial distribution of the economy, transportation routing and planning, traffic management and environmental control. Therefore, knowledge of how to process the data from a standard GPS device is crucial for further use. Previous studies have considered various issues of the data processing at the time. This paper, however, aims to outline a general procedure for processing GPS tracking data. The procedure is illustrated step by step by the processing of real-world GPS data of car movements in Borlänge in the centre of Sweden.     

基于视频图像的目标检测技术研究

本文基于常用运动目标检测方法进行了研究。首先阐述了视频监控系统中常用运动目标检测方法,并对Surendra背景提取算法及改进的帧间差分法进行了说明。运用对称差分法和背景差分法的融合方法进行运动目标检测,实验表明本文运用的方法对运动目标检测具有准确性与实时性。最后得出运用背景差分和帧间差分法的融合检测方法进行运动目标检测,可以得到好的目标检测效果的结论。     

Accuracy of q-space related parameters in MRI: simulations and phantom measurements

The accuracy of q-space measurements was evaluated at a 3.0-T clinical magnetic resonance imaging (MRI) scanner, as compared with a 4.7-T nuclear magnetic resonance (NMR) spectrometer. Measurements were performed using a stimulated-echo pulse-sequence on n-decane as well as on polyethylene glycol (PEG) mixed with different concentrations of water, in order to obtain bi-exponential signal decay curves. The diffusion coefficients as well as the modelled diffusional kurtosis K(fit) were obtained from the signal decay curve, while the full-width at half-maximum (FWHM) and the diffusional kurtosis K were obtained from the displacement distribution. Simulations of restricted diffusion, under conditions similar to those obtainable with a clinical MRI scanner, were carried out assuming various degrees of violation of the short gradient pulse (SGP) condition and of the long diffusion time limit. The results indicated that an MRI system can not be used for quantification of structural sizes less than about 10 microm by means of FWHM since the parameter underestimates the confinements due to violation of the SGP condition. However, FWHM can still be used as an important contrast parameter. The obtained kurtosis values were lower than expected from theory and the results showed that care must be taken when interpreting a kurtosis estimate deviating from zero.     

Protecting the trust and credibility of data by tracking forgery trace based on GANs

With the advent of the 5G Internet of Things era, communication and social interaction in our daily life have changed a lot, and a large amount of social data is transmitted to the Internet. At the same time, with the rapid development of deep forgery technology, a new generation of social data trust crisis has also followed. Therefore, how to ensure the trust and credibility of social data in the 5G Internet of Things era is an urgent problem to be solved. This paper proposes a new method for forgery detection based on GANs. We first discover the hidden gradient information in the grayscale image of the forged image and use this gradient information to guide the generation of forged traces. In the classifier, we replace the traditional binary loss with the focal loss that can focus on difficult-to-classify samples, which can achieve accurate classification when the real and fake samples are unbalanced. Experimental results show that the proposed method can achieve high accuracy on the DeeperForensics dataset and with the highest accuracy is 98%.     

基于MEMS的压阻式超声传感器的设计与测试

A kind of piezoresistive ultrasonic sensor based on MEMS is proposed,which is composed of a membrane and two side beams.A simplified mathematical model has been established to analyze the mechanical properties of the sensor.On the basis of the theoretical analysis,the structural size and layout location of the piezoresistors are determined by simulation analysis.The boron-implanted piezoresistors located on membrane and side beams form a Wheatstone bridge to detect acoustic signal.The membrane-beam microstructure is fabricated integrally by MEMS manufacturing technology.Finally,this paper presents the experimental characterization of the ultrasonic sensor,validating the theoretical model used and the simulated model.The sensitivity reaches -116.2 dB(0 dB reference = 1 V/μbar,31 kHz),resonant frequency is 39.6 kHz,direction angle is 55°.     

一种基于FPGA和超声波的虚拟电子琴设计

介绍了一种以FPGA为核心控制部件、运用超声波测距技术在空间中形成虚拟琴键,使用分频方式实现7个音阶的虚拟电子琴。经过ModelSim仿真测试与实物调试,该电子琴能较好地实现音乐弹奏功能,结构简单,娱乐性强,具有一定的市场推广价值。     

基于FPGA的高速图像跟踪系统设计与实现

常规视觉跟踪系统用于导弹末制导等高速运动中时,图像目标会因出现变形、模糊等现象而影响跟踪精度。针对以上问题,设计实现了基于FPGA的高速图像跟踪系统。该系统通过125fps（frames per second）的高速图像采集目标信息,利用FPGA的并行运算特点,将形心计算嵌入到动态阈值法中来实现高速图像的实时目标检测,并根据形心相对于视场中央的偏移量控制云台跟踪高速运动目标,最后对投影上的目标进行了跟踪仿真实验。结果表明,系统可以实时跟踪高速运动目标,云台的跟踪速度约可达到50．7度/秒,改善了低速图像跟踪系统对高速运动目标跟踪误差大、精度低等问题。     

基于数据分割与主成分分析的LAI遥感估算

针对叶面积指数(LAI)经典统计反演模型存在估算效果不理想以及反演效率低等问题,提出了一种基于农学物候的数据分割与主成分分析结合的遥感估算方法.综合了原始光谱和微分(或差分)光谱主成分信息作为自变量,融入了以农学物候为先验的数据分割思想,并引入了多尺度建模方式参与反演过程.以冬小麦为实验对象,进行数值模拟和比较分析.结...     

Detection of leukocytes in contact with the vessel wall from in vivo microscope recordings using a neural network

Leukocytes play an important role in the host defense as they may travel from the blood stream into the tissue in reacting to inflammatory stimuli. The leukocyte-vessel wall interactions are studied in post capillary vessels by intravital video microscopy during in vivo animal experiments. Sequences of video images are obtained and digitized with a frame grabber. A method for automatic detection and characterization of leukocytes in the video images is developed. Individual leukocytes are detected using a neural network that is trained with synthetic leukocyte images generated using a novel stochastic model. This model makes it feasible to generate images of leukocytes with different shapes and sizes under various lighting conditions. Experiments indicate that neural networks trained with the synthetic leukocyte images perform better than networks trained with images of manually detected leukocytes. The best performing neural network trained with synthetic leukocyte images resulted in an 18% larger area under the ROC curve than the best performing neural network trained with manually detected leukocytes.     

Visualizing the structure of Web communities based on data acquired from a search engine

Discovery of Web communities, groups of Web pages sharing common interests, is important for assisting users' information retrieval from the Web. This paper describes a method for visualizing Web communities and their internal structures. visualization of Web communities in the form of graphs enables users to access related pages easily, and it often reflects the characteristics of the Web communities. Since related Web pages are often co-referred from the same Web page, the number of co-occurrences of references in a search engine is used for measuring the relation among pages. Two URLs are given to a search engine as keywords, and the value of the number of pages searched from both URLs divided by the number of pages searched from either URL, which is called the Jaccard coefficient, is calculated as the criteria for evaluating the relation between the two URLs. The value is used for determining the length of an edge in a graph so that vertices of related pages will be located close to each other. Our visualization system based on the method succeeds in clarifying various genres of Web communities, although the system does not interpret the contents of the pages. The method of calculating the Jaccard coefficient is easily processed by computer systems, and it is suitable for visualization using the data acquired from a search engine.     

2-D locally regularized tissue strain estimation from radio-frequency ultrasound images: theoretical developments and results on experimental data

In this paper, a 2-D locally regularized strain estimation method for imaging deformation of soft biological tissues from radio-frequency (RF) ultrasound (US) data is introduced. Contrary to most 2-D techniques that model the compression-induced local displacement as a 2-D shift, our algorithm also considers a local scaling factor in the axial direction. This direction-dependent model of tissue motion and deformation is induced by the highly anisotropic resolution of RF US images. Optimal parameters are computed through the constrained maximization of a similarity criterion defined as the normalized correlation coefficient. Its value at the solution is then used as an indicator of estimation reliability, the probability of correct estimation increasing with the correlation value. In case of correlation loss, the estimation integrates an additional constraint, imposing local continuity within displacement and strain fields. Using local scaling factors and regularization increase the method's robustness with regard to decorrelation noise, resulting in a wider range of precise measurements. Results on simulated US data from a mechanically homogeneous medium subjected to successive uniaxial loadings demonstrate that our method is theoretically able to accurately estimate strains up to 17%. Experimental strain images of phantom and cut specimens of bovine liver clearly show the harder inclusions.     

基于负载跟踪技术的低漏失大电流LDO的设计

为了满足便携式电子设备的需求,设计了一种低漏失高稳定的LDO.利用正反馈环路钳位电压,获得高精度采样电流.通过调整工作在深线性区的MOS管的等效电阻,产生跟踪负载电流的零点.设置负载电流监测电路,控制大负载电流下的跟踪零点,对输出极点进行补偿.结合阻抗衰减技术,实现LDO在全负载范围内的稳定;通过将第一级运放输出端极点...     

Visualization of big data security: a case study on the KDD99 cup data set

Cyber security has been thrust into the limelight in the modern technological era because of an array of attacks often bypassing untrained intrusion detection systems (IDSs). Therefore, greater attention has been directed on being able deciphering better methods for identifying attack types to train IDSs more effectively. Keycyber-attack insights exist in big data; however, an efficient approach is required to determine strong attack types to train IDSs to become more effective in key areas. Despite the rising growth in IDS research, there is a lack of studies involving big data visualization, which is key. The KDD99 data set has served as a strong benchmark since 1999; therefore, we utilized this data set in our experiment. In this study, we utilized hash algorithm, a weight table, and sampling method to deal with the inherent problems caused by analyzing big data; volume, variety, and velocity. By utilizing a visualization algorithm, we were able to gain insights into the KDD99 data set with a clear identification of “normal” clusters and described distinct clusters of effective attacks.     

基于Thumbs.db文件的数据恢复技术研究与开发

应用软件层的数据恢复,是对某些特殊的文件做分析,解读文件内蕴含的重要信息,恢复出被犯罪嫌疑人删除的作案痕迹、证据等。针对应用软件层的数据恢复研究,以研究Thumbs.db文件格式为例,研究出了怎样在应用软件层,恢复已删除图片的缩略图。并开发出Thumbs.db文件分析软件,通过分析隐藏的系统文件Thumbs.db,可以浏览并保存该文件中记录的包括已删除图片在内的所有图片的缩略图信息。     

“数据信托”探析:基于数据治理与数据资产化的双重视角

在千行百业数字化转型加快推进,数字经济时代全面到来的大背景下,数据要素的重要价值得到普遍重视,与此同时,个人隐私保护与数据安全问题也日益严峻。数据信托作为兼顾数据价值实现与数据权益保护的全新探索,受到国内外广泛关注,形成了数据治理与数据资产化两种不同视角下的发展思路,并加速从理论走向实践。结合我国法律制度环境与数字经济发展战略导向,提出未来我国数字信托发展的设想与建议。     

基于OpenCV的交通视频运动目标检测与跟踪

智能交通系统（ITS）是目前世界交通运输领域正在研究和广泛关注的课题。OpenCV是一种用于数字图像处理和计算机视觉的函数库,由Intel公司开发。本文在目标检测方面,对采集到的交通视频进行灰度化、中值滤波、背景建模、二值化,背景差分等处理,可以较准确地检测出运动目标。在目标跟踪方面,提出了CamShift算法和Kalman滤波器相结合的方法,实现视频车辆的精确跟踪。最后,利用OpenCV的运动物体跟踪的数据结构、函数库,建立了一个视频车辆分析系统。用于道路上车辆的检测与跟踪,并具有良好的鲁棒性。     

柔性凸点热-结构耦合应力应变有限元分析

建立了芯片尺寸封装焊点的柔性凸点三维有限元分析(FEA)模型,对该模型进行了热-结构耦合有限元分析,研究了热-结构耦合条件下柔性凸点温度场和应力应变的分布规律,对比了有无柔性层结构的凸点内应力应变的大小,分析了柔性层厚度、上下焊盘直径对柔性凸点应力应变的影响。结果表明:柔性层结构有效降低了凸点内的应力应变;随着柔性层厚度的增加,凸点内最大应力应变减小;随上焊盘和下焊盘直径的增加,凸点内最大应力应变的变化无明显规律。     

Indoor navigation systems based on data mining techniques in internet of things: a survey

Wireless Networks - Internet of Things (IoT) is turning into an essential part of daily life, and numerous IoT-based scenarios will be seen in future of modern cities ranging from small indoor...     

基于Atmel微控制器的小型数据测量系统的实现

随着无铅焊料应用的普及,无铅焊料焊点的可靠性问题显得尤为重要。美国AT＆T的HAnthony Chan认为电子产品的失效主要源于元件问题、设计不良和组装过程。电子器件服役时,在环境温度变化（或功率循环）时由于芯片与基板、元器件与印制电路板材料热膨胀系数的差异，在焊点内产生热应力而造成焊点的疲劳损伤；相对于服役的环境温度，焊料自身熔点较低，随着时间的延续，产生明显的黏性行为而导致焊点的蠕变损伤。     

基于Java Excel API的数据库数据导入导出方法研究与实现

在Web应用系统中,用户们经常要求将数据库数据进行导入导出处理。Microsoft Excel是用户非常熟悉的办公软件,因此,Excel作为数据库数据导入导出的中间介质成为最佳选择。为了达到此目的,采用Java Excel API操作Excel文件的方法,实现了仅通过在客户端的操作,将数据库中的数据导出到Excel表格中,并将Excel表格中的数据导入数据库的功能。满足了用户进行数据库数据导入导出的要求。