Flight Time Minimization of UAV for Cooperative Data Collection in Probabilistic LoS Channel

This paper investigates the data collection in an unmanned aerial vehicle(UAV)-aided Internet of Things(IoT) network, where a UAV is dispatched to collect data from ground sensors in a practical and accurate probabilistic line-of-sight(LoS) channel. Especially, access points(APs) are introduced to collect data from some sensors in the unlicensed band to improve data collection efficiency. We formulate a mixed-integer non-convex optimization problem to minimize the UAV flight time by jointly designing the UAV 3D trajectory and sensors’ scheduling, while ensuring the required amount of data can be collected under the limited UAV energy. To solve this nonconvex problem, we recast the objective problem into a tractable form. Then, the problem is further divided into several sub-problems to solve iteratively, and the successive convex approximation(SCA) scheme is applied to solve each non-convex subproblem. Finally,the bisection search is adopted to speed up the searching for the minimum UAV flight time. Simulation results verify that the UAV flight time can be shortened by the proposed method effectively.

Evaluation of the Accuracy and Automation of Travel Time and Delay Data Collection Methods

Travel time and delay are among the most important measures for gauging a transportation system’s performance. To address the growing problem of congestion in the US, transportation planning legislation mandated the monitoring and analysis of system performance and produced a renewed interest in travel time and delay studies. The use of traditional sensors installed on major roads (e.g. inductive loops) for collecting data is necessary but not sufficient because of their limited coverage and expensive costs for setting up and maintaining the required infrastructure. The GPS-based techniques employed by the University of Delaware have evolved into an automated system, which provides more realistic experience of a traffic flow throughout the road links. However, human error and the weaknesses of using GPS devices in urban settings still have the potential to create inaccuracies. By simultaneously collecting data using three different techniques, the accuracy of the GPS positioning data and the resulting travel time and delay values could be objectively compared for automation and statistically compared for accuracy. It was found that the new technique provided the greatest automation requiring minimal attention of the data collectors and automatically processing the data sets. The data samples were statistically analyzed by using a combination of parametric and nonparametric statistical tests. This analysis greatly favored the GeoStats GPS method over the rest methods.

STUDY ON MIXIS POTENTIAL OF ROTIFER RESTING EGGS ( BRACHIONUS PLICATILIS ) WITH DIFFERENT COLLECTION TIMES AND DIFFERENT PRESERVATION PERIODS

The present study investigated the possible changes in the mixis potential of rotifer resting eggs produced by a single stock of Brachionus plicatilis and collected and preserved annually from 1985-1998. Several clones derived from each batch of resting eggs were cultured under the same conditions for 21 days. The percentage of clones appearing resting eggs and the average yield of resting eggs produced from each clone were recorded and statistically analyzed to find the differences between the mixis potential of those resting egg batches. Results showed that different batches of resting eggs had different mictic levels among their descendent clones; but no regular relationship was found between the mixis potential of resting eggs and their collection times/preservation periods. Several internal and external factors that might affect the mixis potential of resting eggs were discussed.

Web-based GIS System for Real-time Field Data Collection Using Personal Mobile Phone

Recently, use of mobile communicational devices in field data collection is increasing such as smart phones and cellular phones due to emergence of embedded Global Position System GPS and Wi-Fi Internet access. Accurate timely and handy field data collection is required for disaster management and emergency quick responses. In this article, we introduce web-based GIS system to collect the field data by personal mobile phone through Post Office Protocol POP3 mail server. The main objective of this work is to demonstrate real-time field data collection method to the students using their mobile phone to collect field data by timely and handy manners, either individual or group survey in local or global scale research.

The Time Evolution of Radial Collective Flow in Reaction of ^(197)Au with ^(197)Au at 150 MeV/u

Dynamical time evolution for central collision of 197 Au on 197Au at 150 MeV/u is in-vestigated by using Isospin-dependent Quantum Molecular Dynamics （IQMD） calculation. Thepreequilibrium emission, its influence and the time evolution of radial collective flow are dis-cussed in detail.

Electrocautery vs non-electrocautery dilation catheters in endoscopic ultrasonography-guided pancreatic fluid collection drainage

AIM: To investigate the safety and utility of an electrocautery dilation catheter for endoscopic ultrasonography(EUS)-guided pancreatic fluid collection drainage.METHODS: A single-center, exploratory, retrospective study was conducted between August 2010 and August 2014. This study was approved by the Medical Ethics Committee of our institution. Informed, written consent was obtained from each patient prior to the procedure. The subjects included 28 consecutive patients who underwent EUS-guided transmural drainage(EUS-TD) for symptomatic pancreatic and peripancreatic fluid collections(PFCs) by fine needle aspiration using a 19-gauge needle. These patients were retrospectively divided into two groups based on the use of an electrocautery dilation catheter as a fistula dilation device; 15 patients were treated with an electrocautery dilation catheter(electrocautery group), and 13 patients were treated with a non-electrocautery dilation catheter(non-electrocautery group). We evaluated the technical and clinical successes and the adverse events associated with EUS-TD for the treatment of PFCs between the two groups.RESULTS: There were no significant differences in age, sex, type, location and diameter of PFCs between the groups. Thirteen patients(87%) in the electrocauterygroup and 10 patients(77%) in the non-electrocautery group presented with infected PFCs. The technical success rates of EUS-TD for the treatment of PFCs were 100%(15/15) and 100%(13/13) for the electrocautery and the non-electrocautery groups, respectively. The clinical success rates of EUS-TD for the treatment of PFCs were 67%(10/15) and 69%(9/13) for the electrocautery and the non-electrocautery groups, respectively(P = 0.794). The procedure time of EUS-TD for the treatment of PFCs in the electrocautery group was significantly shorter than that of the non-electrocautery group(mean ± SD: 30 ± 12 min vs 52 ± 20 min, P < 0.001). Adverse events associated with EUS-TD for the treatment of PFCs occurred in 0 patients and 1 patient for the electrocautery and the non-electrocautery groups, respectively(P = 0.942).CONCLUSION: EUS-TD using an electrocautery dilation catheter as a fistula dilation device for the treatment of symptomatic PFCs appears safe and contributes to a shorter procedure time.

VIRTUAL WAITING TIMES IN PRIORITY-M/G/1 QUEUES WITH VACARIONS

In this paper exhaustive-service priority-M/G/1 queueing systems with multiple vacations, single vacation and setup times are studied under the nonpreemptive and preemptive resume priority disciplines. For each of the six models analysed, the Laplace-Stieltjes transform of the virtual waiting time Wk(t) at time t of class k is derived by the method of collective marks. A sufficient condition for , where U has the standard normal distribution, is also given.

摩擦系数连续测量软件中Timer控件的应用

采用VB6.0,结合相应的PCI-7422型数据采集卡等硬件设备,对摩擦系数测量软件系统进行了开发。在该软件系统中,应用VB6.0的2个Timer控件和Windows的多媒体定时器函数,实现了长时间连续实时采集数据、保存数据的功能。

Creative Design Fulfills Brand and Fashion China Fashion Week A/W 2010-2011 Collection held in Beijing

March is a right party time for friends to get together to enjoy the smell of early spring. Moreover, people would like to take off the thick winter coat to showcase their colorful attitude towards the warm spring sunshine. Here, an annual fashion feast in Beijing not only could provide you a visual inspiration of trend, but also would tell you what’s the most "in" factors in the coming season.

Just-In-Time馆藏建设服务在美国的实践（英文）

由日本汽车制造商丰田公司于20世纪中叶创建的Just in Time(JIT)(即时供应)几十年来一直是生产和库存管理的领先理念。美国的图书馆越来越多地将这种理念应用于管理馆藏和服务工作。这与几个世纪以来使用的更传统的Just-in-case(JIC)(备需供应)模型不同。从馆藏选择、馆藏建设、馆藏开发到现在的馆藏服务,分析描述图书馆馆藏专业活动的术语的演变,反映了图书馆在不同的时间建设馆藏的方法。JIT馆藏建设服务已经在美国的大多数图书馆中得到应用。什么是JIT馆藏服务以及它是如何应用的?本文通过美国图书馆的实践描述了JIT模型。

集体记忆的建构——基于新疆兵团军垦体育口述史的考察

为探寻集体记忆的构建逻辑,洞察“小故事”与“大社会”之间的关联机制,遵循“故事—知识”的社会学研究传统,采用口述史访谈方法,结合文献资料和田野调查,对新疆兵团军垦体育的集体记忆进行考察,进一步勾勒出集体记忆“自下而上”实现“小故事与大社会”联结模型。个体基于我“动”故我在,实现身体在微观层面的自我确认,并基于价值信念对身体进行规训,在交往记忆中实现个体运动经验问题化,在中观层面积聚成群体意象,通过代表国家权力的专家系统进行认定,最终完成军垦集体记忆的建构。苦行的身体,家国同构的信仰与栖居的“记忆之场”共同促成集体记忆的建构。既有研究中,经验层面存在“时空在场”维度的忽视有可能导致文化阐释框架的毁坏而引起“记忆氛围”消失。由集体记忆理论进行对话来推进理论至经验研究的演绎进程,进一步丰富集体记忆研究的成果。

基于YOLO模型的车流量实时采集系统研究

对于一座现代化城市来说,合理的交通规划是一个城市高效运行的关键,作为交通规划的关键信息的城市车流量信息,原本需要人工进行识别、获取、验证的提取方式,随着计算机视觉技术的蓬勃发展弊端尽显,终将退出历史的舞台。为了提高城市车流量信息的准确性和及时性,利用现有的计算机技术设计一种基于YOLO模型的车流量实时采集系统。该系统基于YOLO视觉检测模型,采用DeepSORT算法对检测到的目标车辆进行跟踪识别、判断车辆的运行状态、实现当前路段的车流量统计、对已记录车流量信息进行可视化展示以及数据输出等。该系统可以有效地代替传统消耗人力的死板工作,实现自动化数据收集以及道路交通情况的快速监测。该系统操作简单,交互性强,为城市的交通管理和交通规划提供准确实时的信息数据。

基于AUTBUS总线的机载无线柔性分布式测试系统数据同步采集技术

本研究致力于机载无线柔性分布式测试系统的研制,以解决在飞行试验中测试系统占地空间大、线缆使用量大、走线复杂、测试通道数量多等问题。分布式系统的节点分布在不同的位置,其内部时钟可能因多种因素而出现不同步的情况,从而影响数据采集的精度。通过灵活的时隙资源分配机制实现AUTBUS总线的动态调整,确保系统通信的高效稳定。采用1PPS、TOD及AUTBUS总线对表算法,系统能够有效地实现全网节点设备的时间同步,确保各个节点在相同的时间基准上进行协同操作。测试数据同步采集基于外部触发的模数转换模块,在全网协同事件的时刻实现各节点数据的同步采集。测试结果表明系统的同步数据采集精度最低为822.5 ns,满足飞行试验中机载测试的数据采集需求。

基于数据流的织造设备三分量数据清洗算法

织造车间的信息化以数据采集为基础,但采集过程易产生脏数据,为保证数据被准确采集,文章研究了织造车间的数据采集与清洗算法。首先,针对设备多样、数据并发高的特性,设计了分频采集方案和服务器均衡负载方案,以及织造设备数据流处理有向网。其次,针对织造车间的数据特点,将数据分为常分量、增分量和状态分量,并结合箱线图、滑动时间窗研究了三分量清洗算法对各分量数据的清洗。最后,通过实验证明采集方案和数据清洗方法能保证数据采集的实时性、有效性及准确性。

税收征管规范化与企业盈余管理--基于税务行政处罚裁量基准的准自然实验

以2013—2022十年里我国A股上市公司数据为样本探究税收征管规范化与企业盈余管理之间的关系。研究结果表明,各地税务行政处罚裁量基准的实施显著降低了企业的盈余管理水平,并且进一步发现该现象在非国有产权性质和内部控制薄弱的企业中更为明显。

不同采集年份大花红景天种子萌发对温度的响应

为确定温度变化对大花红景天(Rhodiola crenulata)种子萌发的影响,本研究以云南省香格里拉市大雪山居群的种子为材料,探究不同采集年份(2014、2015、2016、2019、2020、2021年)种子的萌发对温度(恒温:1、5、10、15、20、25、30、35℃;变温:15℃/5℃、25℃/15℃)的响应机制。结果表明:大花红景天种子萌发温度阈值较宽,1~35℃均可萌发,具有较宽的萌发温度生态位幅度(0.831~0.891),15~25℃萌发效果最佳;变温与相应恒温相比不能显著增加最终萌发率。通过积温模型模拟,种子萌发最低温度(Tb)为−0.49~0.82℃,萌发最适温度(To)为19.38~20.88℃,萌发最高温度(Tc)为34.21~38.76℃,亚适温条件下的种子萌发积温值为40.7~67.11℃·d。综上,大花红景天种子具有“机会主义”萌发行为,萌发最低温度较低且具有较宽的萌发温度窗口,使其可以在早春大量萌发,以保证幼苗拥有较长的生长季。研究结果为保护与利用野生大花红景天资源提供了一些参考。

海洋垃圾回收船舶路径多目标优化

海洋垃圾污染不仅会破坏海洋生态系统,而且对人类健康也会造成一定的威胁。派遣船舶对近海漂浮的海洋垃圾回收是减少海洋垃圾污染的一种有效方法。由于风和洋流的影响,海洋垃圾的位置是不断变化的。因此,对基于可移动时间窗的海洋垃圾回收船舶路径优化进行了研究,即对同一个垃圾点,设置多个时间跨度适当的时间窗,船舶可以选择在其中一个时间窗内执行收集任务。为了降低船舶回收成本和碳排放量,建立了船舶走行时间和碳排放量的多目标优化模型。并将改进的自适应大规模领域搜索算法作为领域搜索机制,嵌入速度优化,提出了一种基于分解策略的多目标优化算法对其进行求解,即MOEA/D ALNS算法。并通过一组数值实验验证了所提模型和算法的有效性。实验结果表明,与基于遗传算法的MOEA/D算法和NSGA II算法相比,MOEA/D ALNS算法在运行时间和结果上均有明显的优势。此外,对时间窗数量分析可得,随着可移动时间窗数量增多,船舶回收平均成本和碳排放量降低。

基于LSTM网络模型的光伏发电功率短期预测系统

光伏发电受天气因素影响,具有明显的间歇性和波动性特征。该文提出了一种基于LSTM网络模型的光伏发电功率短期预测方法,该方法以STM32单片机为控制核心,实时采集光照辐度、温度、相对湿度、风速等数据。利用相关系数法筛选相关度较高的因素,作为LSTM网络模型的输入变量,对未来光伏发电功率进行短期预测。MATLAB仿真实验结果表明,该文所提方法与其他预测模型相比具有较高的预测精度,在晴天与多云天气下预测的MAPE值分别为4.943%和4.997%,有利于我国电力系统的稳定运行和电网工作人员的调度。

超导磁浮轨道光纤传感监测系统的设计与实现

随着超导材料的发展,超导列车技术发展迅速,针对高温超导磁浮列车会在运行过程中对轨道系统造成影响以及强磁环境下传统电子学传感器难以实现稳定可靠测量的问题,设计了基于光纤传感器的高温超导磁浮列车轨道监测系统,以提高超导磁浮列车运行安全和稳定性。该系统主要包括传感器系统、数据采集及传输系统、智能化监测软件系统以及供配电系统。监测系统提供实时可靠的连续性数据监测,并由解调仪解算各通道传感器数据,通过TCP协议经局域网上传至服务器,由服务器上传至CCU(Central Control Unit)。该系统经过试验验证,实现了多台服务器数据交互、指令发送、在线监测以及数据读取工作,为高温超导磁浮列车可靠运行提供技术支持。

基于血清药理学的肝龙胶囊含药血清制备方法的初步探究

目的:利用血清药理学,探究用于肝细胞脂肪变性药效观察的肝龙胶囊(GLC)含药血清的最佳取血时间和含药血清体积分数。方法:C57BL/6J小鼠60只,灌胃GLC(90 mg/kg),每日两次,连续7 d,分别在末次给药0.5、1、2和4 h心脏采血,收集血清。对照组小鼠灌胃同体积的生理盐水。LC-MS/MS技术检测空白血清及不同采血时间含药血清肌苷含量,确定最佳采血时间。应用0%、1%、3%和10%GLC血清处理棕榈酸(PA)刺激的小鼠肝细胞NCTC1469,尼罗红染色检测细胞脂滴生成,RT-qPCR检测细胞内脂肪酸生成基因Fabp1和Scd1,及脂肪酸β-氧化基因Pparα的表达。结果:(1) LC-MS/MS检测发现在末次给药2 h后血清中肌苷浓度最高。(2)尼罗红染色显示GLC血清对PA诱导的肝细胞脂质积累具有剂量依赖性的减少趋势。(3) 1%和3%和10%GLC血清处理均能显著下调PA刺激的肝细胞内Fabp1和Scd1的表达,且具有剂量依赖性的减少趋势;1%、3%和10%GLC血清处理均能显著上调PA刺激的肝细胞内Pparα的表达,且具有剂量依赖性的增加趋势。结论:小鼠给药后2 h的10%GLC血清是用于肝细胞脂肪变性药效观察的最佳血清干预浓度。