Optical trapping capability of tornado circular Pearcey beams

We systemically investigate optical trapping capability of a kind of tornado waves on Rayleigh particles.Such tornado waves are named as tornado circular Pearcey beams(TCPBs)and produced by combining two circular Pearcey beams with different radii.Our theoretical exploration delves into various aspects,including the propagation dynamics,energy flux,orbital angular momentum,trapping force,and torque characteristics of TCPBs.The results reveal that the orbital angular momentum,trapping force,and torque of these beams can be finely tuned through the judicious manipulation of their topological charges(l_(1)and l_(2)).Notably,we observe a precise control mechanism wherein the force diminishes with|l_(1)+l_(2)|and|l_(1)-l_(2)|,while the torque exhibits enhancement by decreasing solely with|l_(1)+l_(2)|or increasing with|l_(1)-l_(2)|.These results not only provide quantitative insights into the optical trapping performance of TCPBs but also serve as a valuable reference for the ongoing development of innovative photonic tools.

Tornado Impacts in the US from 1950-2015: A GIS-Based Analysis of Vulnerability and Evolving Risk Zones for Human Casualties

The United States is one of the major countries in the world that faces a numerous number of tornadoes every year, directly and indirectly experiencing extensive property damage and human casualties as well as a variety of demographic, socioeconomic, and environmental impacts. This research provides a GIS-based examination of the ways past tornadoes that occurred in the US in the period 1950-2015 have played out in the context of bodily injuries and loss of human life. To this end, the research collected major secondary data (i.e., georeferenced tornado point data) from the Storm Prediction Center (SPC) tornado database and conducted raster-based spatial analysis, utilizing techniques like point density analysis and map algebra to locate areas that have a high risk of tornadoes and to create maps that show relationships between the past tornado events and human casualties. One of the major research findings shown by the spatial analysis was that the geographic areas or regions impacted by tornadoes varied over time. In addition, the statistical results showed a trend that the tornado-prone regions extend from “Tornado Alley” to the states of Illinois, Mississippi, Tennessee, Alabama, and Florida, indicating that the communities in those states that are newly considered to be vulnerable to tornadoes should step up to develop their own tornado mitigation plan to help protect the public and its property from tornadoes. Such plans can play a crucial role in safeguarding the public and protecting property from tornadoes’ potential impact. Additionally, urban planners and policymakers can use this information to make informed decisions about building codes and infrastructure development in tornado-prone areas, potentially reducing the impact of future tornado events on human lives and property.

嵌入式实时集成开发环境TornadoII及其应用

本文通过对嵌入式开发早期历史的介绍，针对其开发过程中遇到的困难，介绍了基于嵌入式实时操作系统VxWorks的新一代嵌入式实时集成开发环境Tornado II的组成及其特点，分析了VxWorks组成及其运行机制，介绍了其相关的支持及有关的应用前景。

基于Tornado的课程管理系统的设计与实现

针对目前智能课堂的研究,关于课程的管理系统就提出来了。因此,开发了一种基于Tornado和React技术的课程管理系统。通过Tornado框架作为后端框架,实现数据库中数据的增、删、改、查操作,Tornado与现在主流的Web服务器框架相比有着明显的优势:它是非阻塞式服务器,而且速度相当快,这对于当下的Web开发来说至关重要。前端部分采用React技术将前台表单中输入的数据传输到后端数据库中,并且对数据库中的数据进行相应的操作,React的一切都是组件化的,使得代码更加的模块化,重用代码将变得更加容易,可维护性极高。该系统的开发过程还彻底的实现了前后端分离,前后端的联系仅靠API联系起来,前端部分的开发引用了Mock-api这一虚拟的服务端接口完成前端部分开发。这一开发技术路线充分展现了Tornado和React对Web开发的优势所在,也可以提高这一系统的可维护性。

基于Tornado码的安全组播源认证方案

组播通信具有动态性和数据传送的不可靠性 ,如何在高丢包率的网络中对组播发送源进行高效认证是安全组播中的一个重要研究方向 .提出了一种对由组播分组哈希认证信息构成的链采用 Tornado抗丢包编码的源认证方案 .该方案减少了每个分组需携带的哈希认证信息大小 ,并在高丢包率的情况下能够得到很高的成功验证概率 .实验仿真的结果表明 ,在相同大小的认证信息下 ,本方案在成功验证概率上优于 EMSS( Efficient Multi- chained Stream Signa-ture)

基于PEG算法的Tornado码构造

Tornado码二部图构造是一个非常重要的问题。基于PEG算法构造LDPC码二部图时显现的各种优点,本文提出了一种改进的PEG构图算法。仿真结果表明,改进的算法比原PEG算法有更快的执行速度,并且基于此算法构造的Tornado码也比原始的Tornado码有更好的性能。

A Brief Discussion on the High-impact Cold-season Tornado Outbreak During 10-11 December 2021 in the United States

An outbreak of powerful tornadoes tore through multiple states in the central and southern United States from 10 to 11 December 2021.It is claimed the deadliest tornado outbreak that has taken place on December days.The National Oceanic and Atmospheric Administration had confirmed 66 tornadoes as of 21 December,producing at least 90 fatalities.Most tornadoes occurred at night and thus they were difficult to be visually located,which directly increases the risk for local residents.Two violent nighttime tornadoes were rated category 4 on the enhanced Fujita scale(EF4).Although a high death toll was caused during this event,the operational service actually presented an excellent performance.This tornado outbreak has aroused extensive discussion from both the public and the research community in China.This paper presents a brief discussion on the formation environment and warning services of the tornado outbreak.Recall the deadliest violent tornado in the past 45 years in China,the radar-based tornadic vortex signatures at the locations with EF4 damages show a comparable strength with those in the current cases.Some views on the tornado warning issuance and receiving and damage surveys in China are also presented.

Applications of Vortex Gas Models to Tornadogenesis and Maintenance

Processes related to the production of vorticity in the forward and rear flank downdrafts and their interaction with the boundary layer are thought to play a role in tornadogenesis. We argue that an inverse energy cascade is a plausible mechanism for tornadogenesis and tornado maintenance and provides supporting evidence which is both numerical and observational. We apply a three-dimensional vortex gas model to supercritical vortices produced at the surface boundary layer possibly due to interactions of vortices brought to the surface by the rear flank downdraft and also to those related to the forward flank downdraft. Two-dimensional and three-dimensional vortex gas models are discussed, and the three-dimensional vortex gas model of Chorin, developed further by Flandoli and Gubinelli, is proposed as a model for intense small-scale subvortices found in tornadoes and in recent numerical studies by Orf et al. In this paper, the smaller scales are represented by intense, supercritical vortices, which transfer energy to the larger-scale tornadic flows (inverse energy cascade). We address the formation of these vortices as a result of the interaction of the flow with the surface and a boundary layer.

基于Tornado和Tilcon的嵌入式GIS图形编辑软件的开发

以VxWorks实时多任务操作系统为应用平台,结合与之配套的软件开发工具Tornado和Tilcon开发出一套嵌入式实时系统GIS图形编辑工具软件。该软件主要用于GIS图形的编辑、以及数据处理,具有移植性强,方便二次开发等优点。

基于MD5加密的Tornado码复制算法改进

基于Tornado码的复制算法具有编解码速度比较快、部分数据丢失时亦能被恢复的优点,但将该算法应用于分布式存储系统时,存在数据易被窃取、篡改的风险.为此,对基于Tornado码的复制算法提出了改进:1)引入加密机制,使数据即使被窃取时也不用担心泄密;2)对原始数据使用MD5算法产生数字指纹,当从分布式存储系统取回数据时,计算数字指纹并与本地的数字指纹对比,就可以判断数据是否被篡改.

基于Tornado的嵌入式软件单元测试

根据嵌入式软件特点,提出一种基于Tornado开发环境的嵌入式软件单元测试方法。该测试方法使用Testbed/Tbrun自动测试工具,借助Tbconfig辅助工具完成Tornado环境下的测试配置,保持测试环境和开发环境的一致性;使用黑/白盒结合的隔离单元测试技术提高测试用例设计质量,快速达到结构覆盖率要求;定制测试报告模板,使用TbrunRe-porter完成测试报告自动生成。该测试方法使测试工作的重心转移到测试用例的设计和执行上,减少代码移植和手动测试报告生成等冗余工作量,极大提高测试效率和测试规范性,已作为一种通用的嵌入式软件单元测试方法在所在测评机构加以推广使用。

Recent Significant Tornadoes in China

1.Introduction Compared with the United States,whose annual number of tornadoes can exceed 1000,the average number of tornadoes per year in China over the past half a century is estimated to be fewer than 100（Fan and Yu,2015）,even though both countries are located in a similar latitudinal zone of the Northern Hemisphere.

Rapid-Scan and Polarimetric Phased-Array Radar Observations of a Tornado in the Pearl River Estuary

The strong destructive winds during tornadoes can greatly threaten human life and destroy property.The increasing availability of visual and remote observations,especially by Doppler weather radars,is of great value in understanding tornado formation and issuing warnings to the public.In this study,we present the first documented tornado over water detected by a state-of-the-art dual-polarization phased-array radar(dual-PAR)in China.In contrast to new-generation weather radars,the dual-PAR shows great advantages in tornado detection for its high spatial resolution,reliable polarimetric variables,and rapid-scan strategy.The polarimetric signature of copolar cross-correlation coefficient with anomalously low magnitude appears to be effective for verifying a tornado and thus is helpful for issuing tornado warnings.The Guangdong Meteorological Service has been developing an experimental X-band dual-PAR network in the Pearl River Delta with the goal of deploying at least 40 advanced dual-PARs and other dual-polarization weather radars before 2035.This network is the first quasi-operational X-band dual-PAR network with unprecedented high coverage in the globe.With such high-performance close-range PARs,efficient operational nowcasting and warning services for small-scale,rapidly evolving,and damaging weather(e.g.,tornadoes,localized heavy rainfall,microbursts,and hail)can be expected.

Mathematical modeling of tornadoes and squall storms

Recent advances in modeling of tornadoes and twisters consist of significant achievements in mathematical calculation of occurrence and evolution of a violent F5-class tornado on the Fujita scale, and four-dimensional mathematical modeling of a tornado with the fourth coordinate time multiplied by its characteristic velocity. Such a tornado can arise in a thunderstorm supercell filled with turbulent whirlwinds. A theory of the squall storms is proposed. The squall storm is modeled by running pertur- bation of the temperature inversion on the lower boundary of cloudiness. This perturbation is induced by the action of strong, hurricane winds in the upper and middle troposphere, and looks like a running solitary wave （soliton）; which is developed also in a field of pressure and velocity of a wind. If a soliton of a squall storm gets into the thunderstorm supercell then this soliton is captured by supercell. It leads to additional pressure fall of air inside a storm supercell and stimulate amplification of wind velocity here. As a result, a cyclostrophic balance inside a storm supercell generates a tornado. Comparison of the radial distribution of wind velocity inside a tornado calculated by using the new formulas and equations with radar observations of the wind velocity inside Texas Tornado Dummit in 1995 and inside the 3 May 1999 Oklahoma City Tornado shows good correspondence.

基于Tornado码的视频抗误码策略

提出了一种适用于H.264编解码过程的抗误码策略,针对自适应FMO模型,在其传输过程中加入Tornado算法,并根据图像强弱运动部分错误掩盖方法的不同,合理地分配传输过程中结点位置,以保证强运动部分获得更高的恢复率,更好地提高图像抗误码性能。实验证明,该策略有效地提高了恢复图像的质量。

实时嵌入式操作系统vxworks及其开发环境Tornado浅析

本文介绍了嵌入时实时系统的发展概况,当前市场上比较流行的vxworks操作系统及其集成开发环境Tornado。Vxworks是Windriver公司为实时嵌入式系统设计开发的操作系统软件,为程序员提供了高效的实时任务调度、中断管理,实时的系统资源以及实时的任务间通信。其核心功能主要有微内核、任务间通信机制、网络支持、文件系统和I/O管理等其他标准支持。

Physically based modeling and animation of tornado

Realistic modeling and rendering of dynamic tornado scene is recognized as a challenging task for researchers of computer graphics. In this paper a new physically based method for simulating and animating tornado scene is presented. We first propose a Two-Fluid model based on the physical theory of tornado, then we simulate the flow of tornado and its interaction with surrounding objects such as debris, etc. Taking the scattering and absorption of light by the participating media into account, the illumination effects of the tornado scene can be generated realistically. With the support of graphics hardware, various kinds of dynamic tornado scenes can be rendered at interactive rates.

Predictability of US tornado outbreak seasons using ENSO and northern hemisphere geopotential height variability

The predictability of dangerous atmospheric phenomena such as tornado outbreaks has generally been limited to a week or less. However, recent work has demonstrated the importance of the Rossby wavetrain phasing over the United States in establishing outbreak-favorable environments. The predictability of Rossby wavetrain phasing is strongly related to numerous climate-scale interannual variability indices, which are predictable many months in advance. To formalize the relationship between interannual variability indices and seasonal tornado outbreak frequency, indices derived from monthly mean Northern Hemisphere 500-hPa and 1000-hPa geopotential height fields and Ni？o 3.4 indices for ENSO phase were compared to annual tornado outbreak seasonal frequencies. Statistical models predicting seasonal outbreak frequency were established using linear（stepwise multivariate linear regressione SMLR） and nonlinear（support vector regressione SVR） statistical modeling techniques.The stepwise methodology revealed predictors that are important in establishing outbreak-favorable environments at long lead times. Additionally, the results of the statistical modeling revealed that the nonlinear SVR technique reduced root mean square errors produced by the control SMLR technique by 28% and provided more consistent forecasts. A preliminary physical analysis revealed that years with high outbreak frequencies were associated with the presence of 500-mb troughs over the central and western US during the peak of outbreak season, while lower frequencies were consistent with ridging over the US or northwest flow over the Plains. These patterns support the results of the statistical modeling, which demonstrate the utility of geopotential height variability as a predictability measure of outbreak frequency.

ON ENVIRONMENTAL CONDITIONS OF THE GENESIS OF TORNADO IN THE ZHUJIANG RIVER DELTA IN SPRING

Using observational data and the data of disastrous investigation of tornado in Zhujiang River Delta and Guangzhou's sounding from March to May of 1976-1983, the environmental conditions of genesis of tornado are analysed and compared with those of nontornadic local storm. It is found that the favorable conditions of genesis of tornado are lower pressure, unstable stratification and stronger wind in the deep layer of troposphere and higher temperature and humidity in low level, among which, lower pressure, more unstable stratification and layer wind are primary conditions for a severe local storm to possibly develop into a storm with accompanying tornado. The tornado mechanism is not related to vertical wind shear.

Tornado API分析及第三方工具链集成技术

分析了Tornado集成开发环境及GCC编译器。重点讨论了Tornado应用程序接口。对Tornado的定制与扩展及第三方工具链的集成技术进行了较深入的探讨。修改GCC-3.3.2部分源码后,采用新的集成策略,把它成功地集成到了Torna-do开发环境中。