Integrated Guidance and Control of Homing Missiles Against Ground Fixed Targets

This paper presents a scheme of integrated guidance and autopilot design for homing missiles against ground fixed targets. An integrated guidance and control model in the pitch plane is formulated and further changed into a normal form by nonlinear coordinate transformation. By adopting the sliding mode control approach, an adaptive nonlinear control law of the system is designed so that the missile can hit the target accurately with a desired impact attitude angle. The stability analysis of the closed-loop system is also conducted. The numerical simulation has confirmed the usefulness of the proposed design scheme.

Analysis of Social Integration Models of Tourism Labor Migrants——A Case Study of Jiuhua Mountain of Anhui Province, China

The grounded theory of qualitative methods was applied to researching the social integration of tourism la-bor migrants in the Jiuhua Mountain of Anhui Province, China. The research was conducted based on the in-depth in-terviewing of 15 samples, open-consultation and the analysis of secondhand data. The integration models of tourism labor migrants in the Jiuhua Mountain were formed through four processes including theoretic sampling, cod-ing-analysis, cross-tabulation and contextualization. The result shows that modes of production and life styles decide self-integration orientation of tourism labor migrants in the Jiuhua Mountain. Cultural differences are fundamental dis-similarity between tourism labor migrants and natives. There are three kinds of integration models including rapid, free and gradually advancing integration. The differences among different types of migrants’ integration models are re-markable. Taking the working integration as the abscissa and taking the life integration as the coordinate, an "S" model of integration matrix appears in the gradually advancing integration of intermediate and high administers from the working to the life which should be paid special attention to.

Grounding Impedance Measurement of High Speed Railway Integrated Grounding System

The high-speed railway integrated grounding system is the basic guarantee for the safe and stable operation of the railway. It is the world’s largest long-distance horizontally elongated joint grounding system, which stretches the length of hundreds to thousands of kilometers, and its structure is not only different from power station and substation grounding system, but also different from the transmission line tower, lightning rod and other small grounding devices. There is little research information on the grounding impedance of high-speed railway integrated grounding system. This paper adopted 0.618 compensation method and reverse away method respectively, measured a section of high-speed railway integrated grounding system grounding impedance by JD16 and CA6425. Measurement results are in good agreement using those two type instrument. By using 0.618 compensation method, the measurement result will be gradually converged at 0.3 Ω with the increasing of current electrode distance, which is the real grounding impedance of integrated grounding system. By using reverse away method, the maximum measurement result difference is less than 0.024 Ω with the lead of current electrode distance increasing. The measurement results will be rapidly converged 0.25 Ω. The results showed that the reverse away method is helpful to shorten the length of current electrode wiring. The measurement error will be small when the current electrode wiring is longer.

Some Tools to Model Ground or Supply Bounces Induced in and out of Heterogeneous Integrated Circuits

Electrical ground looks simple on a schematic; unfortunately, the actual performance of a circuit is dictated by its layout （and by its printed-circuit-board）. When the ground node moves, system performance suffers and the system radiates electromagnetic interferences. But the understanding of the physics of ground noise can provide an intuitive sense for reducing the problem. Ground bounce can produce transients with amplitudes of volts; most often changing magnetic flux is the cause; in this work, the authors use a Finite-Difference Time-Domain to begin to understand such phenomena. Additionally, predicting substrate cross-talks in mixed-signal circuits has become a critical issue to preserve signal integrity in future integrated systems. Phenomena that involve parasitic signal propagation into the substrate are discussed. A simple methodology to predict the substrate cross-talk and some associated tools are presented. Finally, the authors indicate a stochastic method which could grasp both outer or inner RF （Radio-Frequency） radiations and substrate parasites.

Self-organizing strategy design and validation forintegrated air-ground detection swarm

A self-organized integrated air-ground detection swarmis tentatively applied to achieve reentry vehicle landing detection,such as searching and rescuing a manned spaceship. The detectionswarm consists of multiple unmanned aerial vehicles （UAVs）and unmanned ground vehicles （UGVs）. The UAVs can accessa detected object quickly for high mobility, while the UGVs cancomprehensively investigate the object due to the variety of carriedequipment. In addition, the integrated air-ground detectionswarm is capable of detecting from the ground and the air simultaneously.To accomplish the coordination of the UGVs andUAVs, they are all regarded as individuals of the artificial swarm.Those individuals make control decisions independently of othersbased on the self-organizing strategy. The overall requirements forthe detection swarm are analyzed, and the theoretical model ofthe self-organizing strategy based on a combined individual andenvironmental virtual function is established. The numerical investigationproves that the self-organizing strategy is suitable andscalable to control the detection swarm. To further inspect the engineeringreliability, an experiment set is established in laboratory,and the experimental demonstration shows that the self-organizingstrategy drives the detection swarm forming a close range and multiangularsurveillance configuration of a landing spot.

Development and Application of the GIS-Based Water Mass Analysis Integrated System

The research on water masses is always one important facet of Oceanography. I adopt the method of Fuzzy Density Clustering to analyse water masses. Meanwhile, I use Visual Basic 6.0 as developing platform and utilize the MapX components to develop the platform of GIS. By integrating the Water Masses Model compiled by FORTRAN language, and GIS using Tight Coupling, I develop an Integrated System. That makes all phases are finished in one condition, including the gain of computing grid, the pick-up and analysis of data, the choice of parameters and resetting, the computing of model, and the result＇s visualization. It improves the efficiency of the data analysis and decision-making Finally, this system is applied in the Zhoushan fishing ground and adjacent region. The results are satisfying.

Analysis of the integrated test and evaluation methods of tidal current energy generating devices in the offshore testing site

Actual sea condition testing and inspection and evaluation method research are carried out for tidal energy devices to provide scientific and effective technical support for the ocean high-tech achievement transformation and marine renewable energy development. By analyzing three core indicators, including the power output characteristics of the tidal current device, the generating capacity, energy conversion efficiency, proposed the test contents and evaluation methods of indicators are proposed in this paper; and based on the research of wind farms, power quality testing and assessment methods of offshore tidal energy device are proposed; given the security access to the test contents of tidal current energy device, tidal current energy device running conditions in the testing ground are comprehensively assessed.

On time-step in structural seismic response analysis under ground displacement/acceleration

There are two models in use today to analyze structural responses when subjected to earthquake ground motions, the Displacement Input Model （DIM） and the Acceleration Input Model （AIM）. The time steps used in direct integration methods for these models are analyzed to examine the suitability of DIM. Numerical results are presented and show that the time-step for DIM is about the same as for AIM, and achieves the same accuracy. This is contrary to previous research that reported that there are several sources of numerical errors associated with the direct application of earthquake displacement loading, and a very small time step is required to define the displacement record and to integrate the dynamic equilibrium equation. It is shown in this paper that DIM is as accurate and suitable as, if not more than, AIM for analyzing the response of a structure to uniformly distributed and spatially varying ground motions.

Non-axisymmetrical vibration of elastic circular plate on layered transversely isotropic saturated ground

The non-axisymmetrical vibration of elastic circular plate resting on a layered transversely isotropic saturated ground was studied. First, the 3-d dynamic equations in cylindrical coordinate for transversely isotropic saturated soils were transformed into a group of governing differential equations with 1-order by the technique of Fourier expanding with respect to azimuth, and the state equation is established by Hankel integral transform method, furthermore the transfer matrixes within layered media are derived based on the solutions of the state equation. Secondly, by the transfer matrixes, the general solutions of dynamic response for layered transversely isotropic saturated ground excited by an arbitrary harmonic force were established under the boundary conditions, drainage conditions on the surface of ground as well as the contact conditions. Thirdly, the problem was led to a pair of dual integral equations describing the mixed boundaryvalue problem which can be reduced to the Fredholm integral equations of the second kind solved by numerical procedure easily. At the end of this paper, a numerical result concerning vertical and radical displacements both the surface of saturated ground and plate is evaluated.

Precision calculation of crustal deformation induced by radial steady laminellar flow of underground water from single well in multi-layered structural aquifers

According to both the general formula of ground surface displacement by drainage from a well for radial permeable flow of underground water and the drawdown expressions for the flow in multilayered structural aquifers, we have derived the analytical expressions of surface displacement induced by steady flow withdrawal from a full penetrating well on phreatic water and confined water in multilayered structural aquifers and discussed the numerial integration scheme of these analytical expressions. And by means of Hermite′s quadrature formula with 20 nodes, we have made calculational programs and examples to show that the methods mentioned in this paper are effective. We think that these methods lay a foundation to study quantitatively crustal deformation due to groundwater drainage when we are engaged in high precision dynamic geodetic measurement on the area of steady flow of multilayered aquifers.

New Current Mode Lossy Integrator Employing CDDITA

This work presents a novel current-mode (CM) lossless integrator that uses one current differencing differential input transconductance amplifier (CDDITA) and one grounded capacitor. The configuration based on single active element has several advantages from the aspect of monolithic integration, few are: reduced power consumption, chip miniaturization. Employment of grounded capacitor is also beneficial for monolithic integration. Specifying some of the key features of integrator proposed are: 1) purely resistorless, 2) electronically tunable, 3) current output available at the port having high impedance, and 4) excellent performance under non-ideal conditions. So, a resister-less current mode lossy integrator with electronic control employing single CDDITA has been proposed in this paper. The verification of workability of the proposed current mode integrator is well explained by the help of SPICE simulations using TSMC CMOS 0.18 μm technology node.

Ground Magnetic, GPR, and Dipole-Dipole Resistivity for Landfill Investigation

Ground magnetic, ground penetrating radar (GPR), and dipole-dipole resistivity were carried out to environmentally investigate a landfill. In this context, these geophysical techniques were conducted to identify the subsurface contents of the landfill, furthermore, specify any possible leakage and/or contamination in the study area. The ground-magnetic survey carried out in the study area comprised 31 profiles each 120 m in length. Different wavelength filters were applied to the measured data. Vertical derivative, downward continuation, apparent susceptibility, band-pass, and analytical signal filters separated successfully the shallow sources. Whereas, upward continuation and low-pass Gaussian filters isolated significantly the deep magnetic sources. 3D Euler deconvolution (SI = 3) remarkably estimated the depths of the shallow sources (0 - 10 m) of the landfill contents. The conducted GPR and dipole-dipole resistivity allocated tangibly the locations and depths of the near surface anomalies. Both techniques didn’t reveal any possible leakage and/or contamination. Noteworthy, integration among magnetic, GPR, and dipole-dipole resistivity confirmed positively the results of each method. Nevertheless, some anomalies were recognized successfully by one technique and not by the others.

空地协同通信感知一体化系统的轨迹与资源分配联合优化

该文研究空地协同通信感知一体化系统,其中无人车(UGV)基站和无人机(UAV)中继集群组成空地协同网络,为用户提供通信服务,同时对目标区域进行探测感知。在更加准确的莱斯衰落信道模型下,研究联合优化无人机集群的通信感知关联、发射功率和飞行轨迹以及无人车基站的发射功率和行进轨迹,在目标区域感知频率和有效感知功率阈值的约束下,最大化用户最小平均通信速率。为了解决变量高度耦合且非凸的整数优化问题,首先利用块坐标下降法将原问题分解成4个子问题;接着引入松弛变量并将整数约束转化为惩罚项,然后证明莱斯信道下的有效感知功率是关于轨迹变量和松弛变量凸复合函数的联合凸函数;再利用连续凸优化法处理非凸项,并提出一种双层迭代算法高效求解次优解。仿真结果表明,与几种基准方案相比,所提优化算法在相同感知性能下,提高了用户最小平均通信速率,更好地实现了通信与感知性能之间的权衡,并具有良好的收敛性。

县域医共体医防融合实现机制与典型路径

目的:构建县域医共体医防融合实现机制,总结医防融合的典型路径,为其他地区开展基层医防融合提供借鉴和参考。方法:基于扎根理论并借助Nvivo软件进行数据编码及定性分析。结果:确定县域医共体开展医防融合的7个核心维度为体系融、管理融、服务融、人员融、信息融、绩效融和资金融,在实践中仅有少数县域医共体实现了较多维度的融合。结论:将服务融、管理融、信息融放在开展医防融合的首要位置,注重体系融和资金融的均衡设置,参考县域医共体医防融合实践的典型路径,进一步推动医防融合的发展。

天空地一体化多目标跟踪算法研究综述

为实现全时全域“泛在连接”,构建天空地一体化网络已成为国家重大需求,而基于天空地一体化网络下跨域协同系统进行多目标跟踪是其中一个重要的发展方向,其在军民用领域都极具应用价值。本文详细阐述了天空地一体化网络背景下多目标跟踪方法研究进展。首先,介绍了天空地一体化跨域协同多目标跟踪的研究背景与意义。其次,从基于视觉的多目标跟踪、基于模型的多目标跟踪和基于多模态融合的多目标跟踪三个方面概述了当前的代表性研究方法:在基于视觉的多目标跟踪算法方面,介绍了单摄像头和多摄像头融合的多目标跟踪方法;对于基于模型的多目标跟踪,先介绍了单传感器多目标跟踪方法,以及在多种复杂场景下的改进,然后介绍了多传感器融合方法;在基于多模态信息融合的目标跟踪方面,在对多传感器时空配准方法和有代表性的多模态信息融合方法介绍的基础上,概括了基于多模态融合的多目标跟踪算法。最后探讨了当前存在的问题和未来发展方向:无论基于视觉的还是基于模型的多目标跟踪方法都有不少问题有待解决,特别是两种方法的结合值得深入研究;在面临复杂干扰时,基于多传感器信息融合的多目标跟踪由于能实现信息的互补,成为未来的主流发展方向;此外,跨域协同系统,由于能利用更多的资源和信息,其多目标跟踪问题研究极具价值,不过其中通信安全问题和多目标跟踪模型轻量化问题值得探讨。本文对从事目标跟踪及空天地一体化协同控制相关理论与技术研究的科研工作者具有重要参考价值。

古田镇发展旅游业推进乡村振兴的成效与启示——基于扎根理论的研究

上杭古田镇依托当地丰富的红色文化、生态旅游、客家文化等资源,发展特色旅游,推动了乡村振兴。为深入研究古田镇旅游发展与乡村振兴的关系,利用扎根理论,根据收集的资料和实地调研获取的资料,具体分析古田镇旅游业发展在思想、组织、文化、生态、产业、设施、人才等七方面对于乡村振兴的推动作用。古田镇旅游业推动乡村振兴的案例为其他革命老区发展提供了启示:创新旅游管理模式、塑造乡村新型组织,深入挖掘文化资源、培育区域特色,优化基础设施建设、改善农村人居环境,完善人才培养制度、培育乡村旅游型人才。

空地一体遥感技术在轨道交通安全保护区巡查中的应用

随着城市轨道交通建设的不断发展,轨道交通沿线安全保护区巡查工作的范围越来越大,内容越来越多,区域内的情况越来越复杂。针对存在的问题,本文构建了一套空地一体的遥感综合监测体系,在巡查工作中引入航空摄影测量、低空无人机监测、车载全景扫描、定点实时监控等多种遥感监测技术及DSM差分计算、深度学习智能识别等多种数据处理技术,并以上海为例开展应用实践。结果表明,本文方法具有可行性,对建立全覆盖、高频次、智能化的巡查模式有参考借鉴价值。

面向密集场景的空天地网络资源分配算法

空天地网络具有覆盖范围大、吞吐量高、弹性强等优点。该文针对大量用户并发接入、网络负载不均衡所引发的网络拥塞、服务质量恶化等问题,提出一种面向密集场景的资源分配算法。首先以用户需求为中心,根据不同类型用户任务的偏好来构建用户效用函数,然后基于匹配博弈的网络选择算法和结合对偶上升法的功率控制算法来实现负载均衡,优化资源分配方案。实验表明,相较于传统策略,所提策略整体用户接入率至少提高35%,时延和吞吐量方面性能提升超过50%;在密集场景下,能更有效地均衡负载,提升网络性能。

基于AKA的轻量级天地一体化网络终端接入认证方案

针对认证与密钥协商(AKA)协议接入认证方案中存在随机数明文传输、接入点存储成本过高和认证所需的比特通信量大等问题,提出一种轻量级的AKA协议加密接入认证方案。该方案用轻量级的密码算法ZUC加密需要传输的信息,调整信息传输的次序,引入哈希链技术,提高接入认证安全性的同时,减少了通信次数和存储负担,能够更好地适用于计算能力、存储空间、电功率等属性受限、信道带宽受限的天地一体化网络环境。