Classification of Object Tracking Techniques in Wireless Sensor Networks

Object tracking is one of the killer applications for wireless sensor networks (WSN) in which the network of wireless sensors is assigned the task of tracking a particular object. The network employs the object tracking techniques to continuously report the position of the object in terms of Cartesian coordinates to a sink node or to a central base station. A family tree of object tracking techniques has been prepared.In this paper we have summarized the object tracking techniques available so far in wireless sensor networks.

Intravenous Contrast Material Administration at High-pitch Dual-source CT Coronary Angiography: Bolus-tracking Technique with Shortened Time of Respiratory Instruction Versus Test Bolus Technique

Objective To investigate the feasibility of acquiring the similar homogeneous enhancement using bolus-tracking techniques with shortened respiratory time in prospectively electrocardiogram-gated high-pitch spiral acquisition mode (Flash mode) coronary computed tomography angiography (CCTA) compared with test bolus technique. Methods One hundred and eighty-four consecutive patients with mean heart rate ≤65 beats per minute undergoing CCTA were prospectively included in this study. The patients were randomly divided into two groups. Patients in the group A (n=92) instructed to shorten respiratory time received CCTA using bolus-tracking technique with high-pitch spiral acquisition mode (Flash mode), while those in the group B (n=92) underwent CCTA with test bolus technique. The attenuation in the ascending aorta, image noise, contrast-to-noise ratio and radiation doses of the two groups were assessed. Results There were no significant differences in the mean attenuation values in the ascending aorta (483.18±59.07 HU vs. 498.7±83.51 HU, P=0.183), image noise (21.4±4.5 HU vs. 20.9±4.3 HU, P=0.414), contrast-to-noise ratio (12.1±4.2 vs. 13.8±5.1, P=0.31) between the groups A and B. There were no significant differences in the radiation dose of dynamic monitoring scans (0.056±0.026 mSv vs. 0.062±0.018 mSv, P=0.068) and radiation dose of angiography (0.94±0.07 mSv vs. 0.96±0.15 mSv,P=0.926) between the two groups, while 15 mL less contrast material volume was administered in the group A than the group B. Conclusion Bolus-tracking technique with shortened time of respiratory in Flash mode of dual-source CT yields the similar homogeneous enhancement with less contrast material in comparison to the test bolus technique.

RECALLABLE TRACKING TECHNIQUE FOR TOP WELD BEADS OF NARROW GAP SUBMERGED ARC WELDING

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Investigations of Tracking Phenomena in Silicone Rubber Using Moving Average Current Technique

In the present work, tracking phenomenon in Silicone rubber material has beenstudied under AC and DC voltage, with ammonium chloride as a contaminant. It is observed that thetracking is more severe under the DC voltages. The tracking time is less under negative DC comparedto the positive DC voltage. The tracking mechanism is explained in detail. The leakage currentduring the tracking studies was as measured and the moving average technique was adopted tounderstand the trend in current flow. The leakage current magnitude is high with thermally agedspecimens compared to the virgin specimen, irrespective of the type of applied voltage. It isrealized that the tracking time and the leakage current magnitude shows an inverse relationship.

Intravascular ultrasound-guided “extended” reverse controlled antegrade and retrograde subintimal tracking technique using a cutting balloon for recanalizing chronic coronary total occlusion with a side branch

Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) represents the most technically challenging procedure in contemporary interventional cardiology.[1] Blunt lesions and presence of proximal side branch are considered to be strong predictors of reduced technical success.[ 2,3] For such lesions, the antegrade approach may not be feasible or desirable, and the retrograde approach can be used as the initial crossing strategy. However, when treating the blunt CTO with a large side branch proximal to the occlusion, the side branch might be occluded after stent implantation if the retrograde guidewire passed the occluded segment through the subintimal space and re-entered into the true lumen at the opposite side of the side branch.[4] We reported a useful method to solve the above issue which utilizes intravascular ultrasound (IVUS) to guide “extended” reverse controlled antegrade and retrograde subintimal tracking (CART) technique with a cutting balloon.

Cognitive Granular-Based Path Planning and Tracking for Intelligent Vehicle with Multi-Segment Bezier Curve Stitching

Unmanned vehicles are currently facing many difficulties and challenges in improving safety performance when running in complex urban road traffic environments,such as low intelligence and poor comfort perfor-mance in the driving process.The real-time performance of vehicles and the comfort requirements of passengers in path planning and tracking control of unmanned vehicles have attracted more and more attentions.In this paper,in order to improve the real-time performance of the autonomous vehicle planning module and the comfort requirements of passengers that a local granular-based path planning method and tracking control based on multi-segment Bezier curve splicing and model predictive control theory are pro-posed.Especially,the maximum trajectory curvature satisfying ride comfort is regarded as an important constraint condition,and the corresponding curvature threshold is utilized to calculate the control points of Bezier curve.By using low-order interpolation curve splicing,the planning computation is reduced,and the real-time performance of planning is improved,com-pared with one-segment curve fitting method.Furthermore,the comfort performance of the planned path is reflected intuitively by the curvature information of the path.Finally,the effectiveness of the proposed control method is verified by the co-simulation platform built by MATLAB/Simulink and Carsim.The simulation results show that the path tracking effect of multi-segment Bezier curve fitting is better than that of high-order curve planning in terms of real-time performance and comfort.

新版E-tracking技术在颈动脉弹性功能定量研究中的应用

目的探讨新版血管回声跟踪(ET)技术在定量评价颈动脉弹性功能中的价值。方法研究对象为有颈动脉斑块并有相应症状(症状组)、有颈动脉斑块但无相应症状(斑块组)、颈动脉无斑块形成但有高危临床表现(高危组)及健康查体者(对照组),采用新版ET技术对其颈动脉血管弹性功能进行测定,参数包括僵硬度(β)、压力应变弹性系数(Eρ)、顺应性(AC)、增大指数(AI)、脉搏波传导速度(PWVβ)、收缩期内径(Ds)和舒张期内径(Dd),并对症状组和斑块组上述参数进行相关性分析。结果症状组及斑块组双侧颈动脉弹性指标差异无统计学意义,但其Eρ、β、PWVβ、AI及IMT显著高于高危组及对照组,AC显著低于高危组及对照组(P<0.05、0.01);症状组及斑块组PWVβ与β、Eρ和IMT呈正相关,与AC呈负相关,AI与Eρ、β、AC和IMT无明显相关。结论新版ET技术可客观准确反映颈动脉血管的弹性变化,为早期预防和疗效评价提供重要信息。

E-Tracking技术评价系统性红斑狼疮患者颈总动脉弹性的临床意义

目的:探讨血管回声跟踪(E-Tracking,ET)技术检测系统性红斑狼疮患者颈总动脉弹性的临床价值。方法:应用ET技术测量系统性红斑狼疮患者45例及38例正常人同侧颈总动脉的内-中膜厚度(I MT)、弹性模量(Ep)、僵硬度(β)、顺应性(AC)、膨大指数(AI)、脉搏波传导速度(PWVβ)、收缩期血压?舒张期血压及脉压。结果:系统性红斑狼疮组I MT、Ep、β、AI、PWVβ、收缩期血压?舒张期血压?脉压较正常人对照组明显增高(P<0.001),AC较正常人对照组明显减低(P<0.001)。结论:应用血管回声跟踪技术能够定性及定量地检测系统性红斑狼疮患者颈总动脉弹性及功能变化特点,为临床早期预防及干预性药物治疗提供可靠的依据。

eTRACKING技术的原理及参数探讨

目的结合临床应用的体会,探讨eTRACKING的技术原理、公式应用及参数描述的规范。方法采用新版eTRACKING和空气传导脉搏波转换器分别检测管径和脉搏波变化曲线。先用两种方法检测颈总动脉同一部位的管径变化曲线和脉搏波,然后在左右颈总动脉两侧对称的位置同步检测管径变化和脉搏波。结果新版eTRACKING检测Ep、β、AC的精确度较高;脉搏波和管径变化曲线接近,但仍有差异。结论Ep、β、AC的精确度好,得到认可;PWVβ和AI的计算公式尚需在临床研究中进一步验证;eTRACKING术语描述需规范化。

应用新版eTRACKING技术对高血压患者颈动脉斑块的研究

目的应用新版血管回声跟踪eTRACKING技术对高血压患者颈动脉无斑块组与斑块组的特征进行研究。方法高血压颈动脉无斑块组43例,高血压颈动脉软斑组56例,高血压颈动脉硬斑组24例,正常对照组39例。应用新版血管回声跟踪技术评估颈动脉硬化参数,包括压力应变弹性系数(Ep)、硬化参数(β)、顺应性(AC)、脉搏波传导速度(PWVβ)和增大指数(AI),并对高血压组上述参数进行相关分析。结果高血压颈动脉无斑块组与斑块组Ep、β、PWVβ、AI较正常对照组明显增高,AC明显减小(P<0.01);高血压颈动脉硬斑组Ep、β、PWVβ较软斑组明显增高(P<0.01);高血压组的PWVβ与Ep、β呈正相关,与AC呈负相关;高血压组的AI与Ep、β、AC无相关性。结论新版血管回声跟踪技术对高血压颈动脉无斑块组与斑块形成组均有评估价值。

E-tracking技术检测阻塞性睡眠呼吸暂停低通气综合征患者颈动脉血管病变治疗前后变化的研究

目的探讨血管壁回声跟踪技术(E-tracking技术,ET)检测阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者治疗前后颈总动脉血管弹性的变化。方法选取30例OSAHS患者,采用高频线阵探头测量颈总动脉内中膜(IMT),应用ET技术实时跟踪描记治疗前和治疗3个月后的颈动脉管壁运动轨迹,检测出颈动脉的弹性系数(Eρ)、硬化参数(β)、顺应性(AC)、脉搏波传导速度(PWVβ)和增大指数(AI)。结果 OSAHS患者治疗后的颈总动脉较治疗前Eρ、β、PWVβ降低,AC升高(均P<0.01),AI降低(P>0.05)。结论ET技术检测能明确OSAHS患者治疗前后的颈总动脉弹性变化,及早地发现血管病变,有效地指导OSAHS患者的临床治疗。

eTRACKING技术在FMD模式下检测血管内皮功能分析

目的应用eTRACKING技术在FMD模式下实时监测肱动脉血管内径,检测血管内皮功能和管径达峰时间并与应用高频超声连续多次测量反应性充血后的上述指标相比较,分析本法检测血管内皮功能的可行性,比较其精确性。方法将60例正常人分为eTRACKING组和对照组,各30例。eTRACKING组应用eTRACKING技术在FMD模式下实时跟踪肱动脉血管内径,检测血管内皮功能和管径达峰时间。对照组应用高频超声连续多次手工测量反应性充血后的肱动脉内径及达峰时间。观察两组加压前和反应性充血后的肱动脉内径变化及达峰时间。结果eTRACKING组和对照组反应性充血后的肱动脉内径扩张百分率(△%)分别为12.42±1.82%和12.24±1.66%,差异无显著统计学意义(p>0.05);达峰时间分别为74.14±11.96秒和64.07±12.36秒,eTRACKING组的达峰时间明显晚于对照组,差异有显著统计学意义(p<0.01)。结论eTRACKING技术显著提高了血管内皮功能检测的精确度,并能实时检测血管内径变化,具有较高的可行性和可信度。

应用E-tracking技术评价妊娠期高血压疾病患者颈动脉弹性功能

目的:探讨E-Tracking技术在评价妊娠期高血压疾病患者颈动脉弹性功能中的应用价值。方法:对29例妊娠晚期妊娠期高血压疾病患者(疾病组)和32例正常妊娠晚期妇女(对照组)进行双侧颈总动脉血管弹性指标(弹性模量Ep、僵硬度β、顺应性AC、脉搏波传导速度PWVβ及膨大指数AI)及内中膜厚度(IMT)的测量,并进行统计学分析。结果:疾病组双侧颈总动脉Ep、β、PWVβ及AI较对照组升高,疾病组AC较对照组减低,具有极显著性差异(P<0.01);两组间颈总动脉内中膜厚度无显著性差异(P>0.05)。结论:血管回声跟踪技术在评价妊娠期高血压疾病血管弹性方面具有一定价值。

E-tracking技术对妊娠期高血压疾病患者颈动脉弹性功能的研究

目的:探讨血管回声跟踪(E-Tracking,ET)技术评价妊娠期高血压疾病患者颈动脉弹性功能的改变。材料与方法:对妊娠期高血压疾病患者(孕28周后)49例和66例正常妊娠期孕妇(孕28周后)进行双侧颈总动脉血管弹性指标的测量:弹性模量(Eρ)、僵硬度(β)、顺应性(AC)、膨大指数(AI)和脉搏波传导速度(PWVβ),并进行统计学分析。结果:妊娠期高血压疾病组双侧颈总动脉Eρ、β、AC及AI较对照组升高,AC较对照组减低,具有显著性差异(P<0.05,P<0.01)。结论:血管回声跟踪技术能较早、明确的反映妊娠期高血压疾病患者颈动脉弹性功能的改变,具有一定价值。

e-Tracking技术评估不同冠脉狭窄程度与颈动脉弹性的相关性

目的应用血管回声跟踪(e-Tracking)技术评估不同冠脉狭窄程度与颈动脉弹性的相关性。方法选择拟诊冠心病在我院行冠脉造影的患者180例,根据冠脉造影结果分为冠脉无狭窄组(A组)、轻度狭窄组(B组)、中度狭窄组(C组)、重度狭窄组(D组),D组又根据病变血管数量分为D1、D2、D3组,每组30例,应用常规二维超声测量颈动脉内膜中层厚度(IMT)和e-Tracking技术检测颈动脉弹性(Eρ、β、AC、AI、PWVβ),并进行统计学分析。结果随着冠脉狭窄程度的加深,IMT、Eρ、β、AI、PWVβ值升高而AC值降低,各参数总体比较差异均有统计学意义;排除年龄、BMI、TC等混杂因素后,Eρ、β对血管弹性的检测最为敏感,除D2和D3组之外,各组之间比较差异均有统计学意义;其次是AC,血管顺应性与冠脉狭窄程度呈反比,但当血管狭窄到一定程度时(≥75%),单支病变与多支病变间无统计学意义;IMT在A和B组、A和C组、B组和C组间比较差异均无统计学意义。结论冠脉狭窄越严重,颈动脉弹性受损越明显,其中Eρ、β在评估冠脉狭窄程度与颈动脉弹性相关性的敏感性较高,IMT在冠脉狭窄程度较轻时变化不显著,当多支冠脉狭窄≥75%时,2支与≥3支血管病变中颈动脉总体弹性变化差异不大。

Test Bolus法与Bolus Tracking法在头颈CTA中的对比研究

目的通过Test Bolus法与Bolus Tracking法在头颈CTA扫描技术的图像质量对比,探讨头颈CTA扫描的最佳扫描技术。方法选取头颈CTA检查Test Bolus法和Bolus Tracking法的患者各30例,将扫描数据进行图像后处理,主观评价采用五分法,客观评价分别在主动脉弓、颈总动脉和大脑中动脉M1段血管内测量CT值,分析两种扫描方法的主观评价和客观评价差异性比较。结果主观评价图像质量Test Bolus法优于Bolus Tracking法,差异具有统计学意义(P﹤0.05)。客观评价血管内CT值Test Bolus法均高于Bolus Tracking法,主动脉弓血管内CT值差异无统计学意义(P﹥0.05);颈总动脉和大脑中动脉M1段管内CT值差异具有统计学意义(P﹤0.05)。结论在头颈CTA扫描技术中,Test Bolus法扫描可准确计算CTA的扫描启动时间,可以获取最佳扫描时机。

An Ensemble Learning Based Approach for Detecting and Tracking COVID19 Rumors

Rumors regarding epidemic diseases such as COVID 19,medicines and treatments,diagnostic methods and public emergencies can have harmful impacts on health and political,social and other aspects of people’s lives,especially during emergency situations and health crises.With huge amounts of content being posted to social media every second during these situations,it becomes very difficult to detect fake news(rumors)that poses threats to the stability and sustainability of the healthcare sector.A rumor is defined as a statement for which truthfulness has not been verified.During COVID 19,people found difficulty in obtaining the most truthful news easily because of the huge amount of unverified information on social media.Several methods have been applied for detecting rumors and tracking their sources for COVID 19-related information.However,very few studies have been conducted for this purpose for the Arabic language,which has unique characteristics.Therefore,this paper proposes a comprehensive approach which includes two phases:detection and tracking.In the detection phase of the study carried out,several standalone and ensemble machine learning methods were applied on the Arcov-19 dataset.A new detection model was used which combined two models:The Genetic Algorithm Based Support Vector Machine(that works on users’and tweets’features)and the stacking ensemble method(that works on tweets’texts).In the tracking phase,several similarity-based techniques were used to obtain the top 1%of similar tweets to a target tweet/post,which helped to find the source of the rumors.The experiments showed interesting results in terms of accuracy,precision,recall and F1-Score for rumor detection(the accuracy reached 92.63%),and showed interesting findings in the tracking phase,in terms of ROUGE L precision,recall and F1-Score for similarity techniques.

Lightning Nowcasting with an Algorithm of Thunderstorm Tracking Based on Lightning Location Data over the Beijing Area

A thunderstorm tracking algorithm is proposed to nowcast the possibility of lightning activity over an area of concern by using the total lightning data and neighborhood technique.The lightning radiation sources observed from the Beijing Lightning Network(BLNET)were used to obtain information about the thunderstorm cells,which are significantly valuable in real-time.The boundaries of thunderstorm cells were obtained through the neighborhood technique.After smoothing,these boundaries were used to track the movement of thunderstorms and then extrapolated to nowcast the lightning approaching in an area of concern.The algorithm can deliver creditable results prior to a thunderstorm arriving at the area of concern,with accuracies of 63%,80%,and 91%for lead times of 30,15,and 5 minutes,respectively.The real-time observations of total lightning appear to be significant for thunderstorm tracking and lightning nowcasting,as total lightning tracking could help to fill the observational gaps in radar reflectivity due to the attenuation by hills or other obstacles.The lightning data used in the algorithm performs well in tracking the active thunderstorm cells associated with lightning activities.

A robust system for real-time pedestrian detection and tracking

A real-time pedestrian detection and tracking system using a single video camera was developed to monitor pedestrians. This system contained six modules: video flow capture, pre-processing, movement detection, shadow removal, tracking, and object classification. The Gaussian mixture model was utilized to extract the moving object from an image sequence segmented by the mean-shift technique in the pre-processing module. Shadow removal was used to alleviate the negative impact of the shadow to the detected objects. A model-free method was adopted to identify pedestrians. The maximum and minimum integration methods were developed to integrate multiple cues into the mean-shift algorithm and the initial tracking iteration with the competent integrated probability distribution map for object tracking. A simple but effective algorithm was proposed to handle full occlusion cases. The system was tested using real traffic videos from different sites. The results of the test confirm that the system is reliable and has an overall accuracy of over 85%.

Changes in Gaze Behavior during the Learning of the Epidural Technique with a Simulator in Anesthesia Novices

Background: Current literature demonstrates the ability of eye tracking to provide reliable quantitative data as an objective assessment tool, with potential applications to medical and surgical training to improve performance. Objective: The aim of this study was to evaluate the changes in gaze behavior in anesthesia novice trainees when performing a simulated epidural technique before and after a hands-on training on the epidural simulator. Methods: We enrolled 48 novice trainees who had never previously performed an epidural block. After a standardized learning module, each trainee practiced the epidural procedure on the epidural simulator while wearing a pair of eye tracking glasses (Tobii Pro Glasses 50 Hz wearable wireless eye tracker). After this baseline recording, each trainee spent two hours practicing with the epidural simulator and afterwards once again performed the eye tracking epidural procedure. Eye tracking metrics and epidural learning (duration of the procedure and number of attempts) before and after the simulated practice were recorded. Results: The duration of the epidural procedure and of the epidural needle advancement phase (P < 0.05) and the number of epidural attempts (P < 0.001) were reduced after the tutorial. When considering the eye tracking metrics, after the tutorial, the number of visit counts decreased and their duration increased (P < 0.05). The number of epidural needle insertions (additional attempts) showed a significant positive correlation with the visits number (aOR = 2.02 (95% CI = 1.26 - 3.55;P = 0.008)) and a significant negative correlation with the visit duration (aOR = 0.65 (95% CI = 0.39 - 0.99;P = 0.05)). Conclusion: We observed significant changes in gaze behavior associated with increased performance during the epidural technique learning with a simulator in anesthesia trainees who had never previously performed an epidural block. These results may create a prototype for future studies on eye tracking technique as a teaching and evaluating tool in simulation.