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| 1 | GPS PPP技术用于滑坡监测的试验与结果分析显示文摘为了研究全球定位系统(GPS)精密单点定位(PPP)技术用于滑坡等地质灾害监测时可能达到的精度和可靠性等问题,结合某类滑坡的大型物理模型试验,在滑坡体上布设了若干GPS监测点进行连续实时动态监测,利用PPP技术对该滑坡从稳定、开始滑动直至产生破坏的全过程监测数据进行了处理与分析,并与GPS单历元差分定位、载波相位实时差分定位技术监测结果进行了对比。结果表明:GPS PPP技术监测结果的内符合精度约为10 mm,外符合精度约为40 mm,且GPS PPP技术具有一些差分GPS无法比拟的优势,如无需基准站支持、作业成本低、效率高、可直接获取监测点在国际地球参考框架下的绝对坐标等。该技术完全可用于滑坡等地质灾害的实时动态监测和预警。 | 王利 张勤 黄观文 涂锐 张双成 | 2014 | 岩土力学2014，35，7： | 31 |
| 2 | GNSS非差非组合精密单点定位的理论方法与应用研究张宝成显示文摘由美国GPS、俄罗斯GLONASS、欧盟Galileo和中国'北斗'联合组成的全球导航卫星系统(global navigation satellite system,GNSS)现已广泛地服务于地球和空间科学领域。最优地融合各类GNSS的观测数据,以快速、准确地估计位置、速度、时间、大气等参数,是当前和未来阶段的研究热点。为实现此目的,本文对精密单点定位(precise point positioning,PPP) | 张宝成 | 2014 | 测绘学报2014，43，10： | 33 |
| 3 | Barometric altimetry system as virtual constellation applied in CAPS显示文摘This work describes the barometric altimetry as virtual constellation applied to the Chinese Area Positioning System (CAPS), which uses the transponders of communication satellites to transfer navigation messages to users. Barometric altimetry depends on the relationship of air pressure varying with altitude in the Earth’s atmosphere. Once the air pressure at a location is measured the site altitude can be found. This method is able to enhance and improve the availability of three-dimensional positioning. The difficulty is that the relation between barometric pressure and altitude is variable in different areas and under various weather conditions. Hence, in order to obtain higher accuracy, we need to acquire the real-time air pressure corresponding to an altimetric region’s reference height. On the other hand, the altimetry method will be applied to satellite navigation system, but the greatest difficulty lies in how to get the real-time air pressure value at the reference height in the broad areas overlaid by satellite navigation. We propose an innovational method to solve this problem. It is to collect the real-time air pressures and temperatures of the 1860 known-altitude weather observatories over China and around via satellite communication and to carry out time extrapolation forecast uniformly. To reduce data quantity, we first partition the data and encode them and then broadcast these information via navigation message to CAPS users’ receivers. Upon the interpolations being done in receivers, the reference air pressure and temperature at the receiver’s nearby place is derived. Lastly, combing with the receiver-observed real air pressure and temperature, the site’s altitude can be determined. The work is presented in the following aspects: the calculation principle, formulae, data collection, encoding, prediction, interpolation method, navigation message transmission together with errors causes and analyses. The advantages and shortcomings of the technique are discussed at the end. | AI GuoXiang SHENG PeiXuan DU JinLin ZHENG YongGuang CAI XianDe WU HaiTao HU YongHui HUA Yu LI XiaoHui | 2009 | Science China(Physics,Mechanics & Astronomy)2009，52，3： | 22 |
| 4 | Third-order point contact approach for five-axis sculptured surface machining using non-ball-end tools(II): Tool positioning strategy显示文摘Based on the mathematical model describing the third-order approximation of the cutter envelope surface according to one given cutter location(CL),a tool positioning strategy is proposed for efficiently machining free-form surfaces with non-ball-end cutters.The optimal CL is obtained by adjusting the inclination and tilt angles of the cutter until its envelope surface and the design surface have the third-order contact at the cutter contact(CC)point,which results in a wide machining strip.The strategy can handle the constraints of machine joint angle limits,global collision avoidance and tool path smoothness in a nature way,and can be applied to general rotary cutters and complex surfaces.Numerical examples demonstrate that the third-order point contact approach can improve the machining strip width greatly as compared with the recently reported second-order one. | ZHU LiMin 1 ,DING Han 2 &XIONG YouLun 2 1State Key Laboratory of Mechanical System and Vibration,Shanghai Jiao Tong University,Shanghai 200240,China 2State Key Laboratory of Digital Manufacturing Equipment and Technology,Huazhong University of Science and Technology,Wuhan 430074, China | 2010 | Science China(Technological Sciences)2010，53，8： | 23 |
| 5 | Full-scale measurements of dynamic response of suspension bridge subjected to environmental loads using GPS technology显示文摘Nowadays, there are many larger and taller engineering structures than in the past. These structures are commonly designed to be more flexible. Thus, they are sensitive to severe wind gust and earthquake tremor. For the dynamic response prediction, finite element (FE) modal updating and structural health monitoring, the dynamic characteristics of a structure are becoming increasingly important. The aim of this paper is to show an emerging tool-the real time kinematic (RTK) global positioning system (GPS), which is used to measure and monitor the low-frequency vibration of Dalian BeiDa Bridge, a medium span suspension bridge. The modal analysis is firstly performed on the developed three-dimensional FE model according to the original blue prints of the bridge to provide the analytical frequencies and mode shapes. The field ambient vibration tests using the accelerometers on the bridge deck are conducted just prior to the use of the GPS system in order to validate the FE model. And then, the calibration test is done to assess the dynamic displacement measurement accuracy of the GPS in three orthogonal directions. The GPS signal properties, such as the amplitude, standard deviations (STD), power spectral density (PSD), and probability density functions (PDF), are studied in details. After that, a structural health monitoring system based on the GPS is devised and installed on the bridge to provide real-time measurement of deck movement. The output-only modal parameter identification is carried out by using the Periodogram method to investigate the responses of the bridge. The result shows that the spectral densities of the displacements measured by the GPS correspond well with the results by the FEM analysis and the accelerometer vibration test. It is concluded that the GPS method is reliable and useful to clarify the ambient vibration response behaviors of the flexible structures. The integration of the GPS and accelerometer methods results in a hybrid arrangement that can help to eliminate some disadvantages of the two devices used separately. | YI TingHua1,2, LI HongNan1 & GU Ming2 1State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, China 2State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China | 2010 | Science China(Technological Sciences)2010，53，2： | 18 |
| 6 | Recent research and applications of GPS based technology for bridge health monitoring显示文摘Today,long-span bridges are being designed to be more flexible and to resist extensive impacts from changes in temperature,severe wind gusts and earthquake tremors. Structural responses (especially displacement) of bridge structures are becoming increasingly important for the finite element (FE) modal updating,structural response prediction and safety evaluation. Methods of global displacement sensing were developed for these needs. This paper presents an overview of current research and development activities in the field of bridge health monitoring using the global positioning system (GPS). The GPS monitoring technology and its accuracy assessment method are also briefly described. Finally,existing problems and promising research efforts in the GPS based bridge health monitoring are discussed. | YI TingHua1,2, LI HongNan1 & GU Ming2 1 Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian 116023, China 2 State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China | 2010 | Science China(Technological Sciences)2010，53，10： | 18 |
| 7 | 一种基于P码的频域直接捕获算法的研究显示文摘GPS(Global Positioning System)系统采用典型的CDMA(Code Division Mutiple Access)体制,目前扩频PRN码主要是用于标准定位服务的C/A码和用于精确定位服务的P码.P码信号具有很强的抗干扰和保密能力,而P码的捕获通常是利用C/A码来完成的,因此,实现P码的直接捕获对我国未来发展自己的卫星定位系统具有重要意义.本文从研究信号直接捕获算法角度出发,提出了一种新的P码快速直接捕获算法,并通过仿真实验验证了算法的有效性.仿真结果表明,该算法有效地提高了捕获效率. | 田明浩 冯永新 潘成胜 | 2007 | 电子学报2007，35，3： | 18 |
| 8 | Progresses and Prospects of Marine Geodetic Datum and Marine Navigation in China显示文摘Territorial water is a significant part of national sovereignty of China,thus the infrastructures of national space datum and location services should cover the sea areas except for the land areas.China has established relatively complete geodetic coordinate frame in land areas over the past decades,including the lastest developed China Geodetic Coordinate System 2000(CGCS 2000)with its reference frame and the national gravity datum 2000.However,the currently used geodetic infrastructures have not well covered the sea areas of China.The marine geodetic datum and marine navigation technologies need to be further developed and extended to satisfy the national demands of marine environment and resources detection,scientific investigation as well as marine economy development in new era of China.This paper mainly reviews the development and the progress of Chinese marine geodetic datum and marine navigation,analyses related key technologies in establishing our national marine geodetic datum.Some current trends and future directions for independently developing our national marine geodetic datum and marine navigation technologies are discussed. | Yuanxi YANG Tianhe XU Shuqiang XUE | 2018 | Journal of Geodesy and Geoinformation Science2018，1，1： | 16 |
| 9 | Phasor measurement units, WAMS, and their applications in protection and control of power systems显示文摘The paper provides a short history of the phasor measurement unit(PMU) concept. The origin of PMU is traced to the work on developing computer based distance relay using symmetrical component theory. PMUs evolved from a portion of this relay architecture. The need for synchronization using global positioning system(GPS) is discussed, and the wide area measurement system(WAMS) utilizing PMU signals is described. A number of applications of this technology are discussed, and an account of WAMS activities in many countries around the world are provided. | Arun G.PHADKE Tianshu BI | 2018 | Journal of Modern Power Systems and Clean Energy2018，6，4： | 16 |
| 10 | Progress in image-guided radiotherapy for the treatment of non-small cell lung cancer显示文摘Lung cancer is one of the most common malignant tumors. It has the highest incidence and mortality rate of all cancers worldwide. Late diagnosis of nonsmall cell lung cancer(NSCLC) is very common in clinical practice, and most patients miss the chance for radical surgery. Thus, radiotherapy plays an indispensable role in the treatment of NSCLC. Radiotherapy technology has evolved from the classic two-dimensional approach to three-dimensional conformal and intensity-modulated radiotherapy. However, how to ensure delivery of an accurate dose to the tumor while minimizing the irradiation of normal tissues remains a huge challenge for radiation oncologists, especially due to the positioning error between fractions and the autonomous movement of organs. In recent years, image-guided radiotherapy(IGRT) has greatly increased the accuracy of tumor irradiation while reducing the irradiation dose delivered to healthy tissues and organs. This paper presents a brief review of the definition of IGRT and the various technologies and applications of IGRT. IGRT can help ensure accurate dosing of the target area and reduce radiation damage to the surrounding normal tissue. IGRT may increase the local control rate of tumors and reduce the incidence of radio-therapeutic complications. | Xiao-Cang Ren Yue-E Liu Jing Li Qiang Lin | 2019 | World Journal of Radiology2019，11，3： | 14 |
| 11 | 基于人工神经网络的百度地图坐标解密方法显示文摘提出了一种针对百度地图坐标加密算法的解密方法,利用百度开放的坐标转换接口获取多组GPS和百度地图坐标对,基于BP神经网络拟合出逆转换函数,利用训练后的BP网络来预测新的百度坐标所对应的GPS坐标。实验结果证明,该方法得到的GPS坐标与实际的GPS坐标较为接近,因而可以达到较为理想的解密结果。 | 潘伟洲 陈振洲 李兴民 | 2014 | 计算机工程与应用2014，50，17： | 13 |
| 12 | Wide area real time kinematic decimetre positioning with multiple carrier GNSS signals显示文摘This paper presents the technical basis for wide area real time decimetre positioning services using multiple carrier signals transmitted by future GNSS such as modernized GPS and Compass systems. The first step is to form two ionosphere-reduced extra-widelanes (EWL) that have the minimal total noise levels in cycles, considering the effects of the ionospheric and tropospheric delays, orbital error, and phase noise terms in various observational environments. The proposed three carrier ambiguity resolution approach can determine the integer ambiguities of the selected EWL signals with geometry-free and geometry- based estimations respectively over the distances of typically hundreds of kilometres. With two ambiguity-fixed EWL signals, the kinematic positioning solutions can be achieved in decimetre level accuracy. A semi-simulation method is employed to generate three frequency Compass data to demonstrate the above expected performance for decimetre positioning services. Both theoretical and experimental results have demonstrated the overall 3D root mean square accuracy of better than 15 cm obtained through with a phase smoothing process over 120 epochs. The dominating error factor in this positioning result is the residual tropospheric biases, which would become less correlated as the baselines grow beyond hundreds of kilometres. With respect to dual-frequency based precise point positioning and wide area differential positioning solutions, a major advantage of using the third frequency signals is the convergence time being shorten from tens of minutes to a few minutes. In addition, due to the instant ambiguity resolution capability, phase breaks or cycle slips no longer affect the continuity of the solutions. This reliable decimetre positioning capability introduces a significant improvement to safety-of-life, liability-critical and professional applications. | FENG YanMing1 & LI BoFeng1,2 1 Faculty of Science and Technology, Queensland University of Technology, GPO Box 2434, QLD 4001, Australia 2 Department of Surveying and Geo-informatics Engineering, Tongji University, Shanghai 200092, China | 2010 | Science China Earth Sciences2010，53，5： | 11 |
| 13 | 基于扩展卡尔曼滤波的GPS定位数据处理方法研究显示文摘由于GPS信号容易受到遮挡、干扰等影响,有时会存在较大的系统噪声和量测噪声,这将引起GPS的定位精度受到较大影响。研究了一种利用扩展卡尔曼滤波对GPS定位数据进行处理的方法。对扩展卡尔曼滤波算法进行了深入分析,并结合GPS应用建立了系统的动态模型,对滤波算法的初值和系统噪声的进行了探讨。通过实测GPS数据对扩展卡尔曼滤波算法进行了验证,实测结果表明该算法对GPS应用系统的定位数据有较好的滤波效果,可以有效的提高GPS的定位精度。 | 徐宏宇 王浩 王尔申 | 2012 | 科学技术与工程2012，20，31： | 11 |
| 14 | Present-day crustal movement and tectonic deformation in China continent显示文摘Velocity field of China continent constrained by Global Positioning System (GPS) reveals both continuous and block-like styles of deformation. Continuous deformation commonly characterizes actively deforming mountain ranges such as the Tianshan Mountain, Qilian Mountain, and Tibet. The block-like movement often represents deformation in the tectonically stable regions such as Ordos, South China and Tarim blocks. GPS measurements indicate 5.1±2.5 mm/a left-lateral strike-slip rate along the Altun fault. Eastward convergence along the Longmenshan fault is less than 6.7±3.0 mm/a. South China moves 11-14 mm/a eastward compared with the stable Eurasia. These low slip rates do not imply rapid eastward extrusion of China continent predicted by the model of 'continental extrusion'. It appears that 'crustal thickening' model more properly describes both continuous and block-like styles of deformation in China continent. | 王琪 张培震 牛之俊 赖锡安 J.T.Frevmueller 朱文耀 刘经南 李延新 R.Bilham K.M.Larson | 2002 | Science China Earth Sciences2002，45，10： | 10 |
| 15 | Design of a control system for a macro-micro dual-drive high acceleration high precision positioning stage for IC packaging显示文摘A macro-micro dual-drive positioning system showing good potential for high acceleration and high precision positioning required in IC packaging applications is devised in this paper. The dual-drive positioning stage uses a VCM (voice coil motor) driven macro positioning stage and a PZT piezo-electric driven micro positioning stage. The coupling characteristics of the system are analyzed to produce a control structure with a micro positioning stage that can dynamically compensate for the positioning error produced by the macro positioning stage. Models of the two positioning stages are described. The models cover both the mechanism and the actuator. For the macro positioning stage, friction characteristics are taken into account, and a controller with an LQG (linear-quadratic-Gaussian) control algorithm combining a feed-forward compensation algorithm is derived. A PID controller is used to control the micro positioning stage. Detailed designs are derived for the proposed approach, and the performance is validated by simulation. | LIU YanJie LI Teng SUN LiNing | 2009 | Science China(Technological Sciences)2009，52，7： | 10 |
| 16 | Multi-life cycles utilization of retired satellites显示文摘Retired geosynchronous (GEO) communication satellites affect the GEO orbit environment in outer space. According to the new concept of modern design, the authors propose creatively a method of reusing retired GEO communication satellites, through adjusting retired GEO satellites to slightly inclined orbit geosynchronous (SIGSO) satellites. After these retired satellites are applied to the navigation and communication system, integrity of navigation system and positioning accuracy of the system is improved. Meanwhile, some transponders on these retired satellites can be used to establish a new satellite communication service, and initiate the study and utilization of the multi-life cycle for retired satellites. Experimental results show that this project has significant social value and can make remarkable economic benefit. | SHI HuLi AI GuoXiang HAN YanBen MA LiHua CHEN JiBin GENG JianPing | 2009 | Science China(Physics,Mechanics & Astronomy)2009，52，3： | 9 |
| 17 | 校园漫游互动AR系统设计与实现显示文摘各类高校导航应用层出不穷,导航应用服务功能上依旧有所欠缺,只能简单指示用户的室外位置,不包含详细介绍信息,甚至部分地点不能指明位置,系统开发周期较长,同时没有实时互动漫游效果。设计了一个校园漫游互动AR系统,结合GPS模块进行室外定位,运用深度学习技术实现校园室内定位,采用增强现实(AR)技术提高系统的可交互性。实验结果表明,提出的校园漫游互动AR系统能较为有效的进行校园定位,在此基础上拓展的漫游服务能够为来访者实时提供高校信息,进一步为校园文化传播提供平台。 | 秦胜伟 李重 李金锋 陈梓浩 丁靖骞 刘万顺 | 2019 | 系统仿真学报2019，31，7： | 9 |
| 18 | A Single-Site Positioning Method Based on TOA and DOA Estimation Using Virtual Stations in NLOS Environment显示文摘This paper presents a single-site positioning method based on the joint estimation of propagation time-of-arrival(TOA) and direction-of-arrival(DOA), with the assist of virtual stations in the typical non-line-of-sight(NLOS) environment. Consider the influence of multipath noise on the positioning performance, the proposed method firstly presents a modified high-resolution estimation technique called Multipath noise Limiting Matrix Pencil(MLMP) algorithm to achieve the TOA/DOA estimations, in which the matrix pencil and matrix enhancement process are implemented to deal with the measurements from the uniform linear array(ULA) receiver. Meanwhile, the subspace dimension estimation is improved via an adaptive threshold, for enhancing the performance of high-resolution techniques in low signal-noise-ration(SNR) situation. Next the proposed method generates virtual stations utilizing the known floor plan of surrounding reflectors, and adopts a weighted Least Square(WLS) position estimator to calculate the required position, combining the TOA/DOA estimations with the location of virtual stations. Simulations are conducted to evaluate the proposed method under NLOSconditions, and the results show that comparing with the multipath fingerprinting scheme, the proposed method has better performance in various simulation scenarios. | Rui Zhang Weiwei Xia Feng Yan Lianfeng Shen | 2019 | China Communications2019，16，2： | 9 |
| 19 | Improving the accuracy of image-based forest fire recognition and spatial positioning显示文摘Forest fires are frequent natural disasters.It is necessary to explore advanced means to monitor,recognize and locate forest fires so as to establish a scientific system for the early detection,real-time positioning and quick fighting of forest fires.This paper mainly expounds methods and algorithms for improving accuracy and removing uncertainty in image-based forest fire recognition and spatial positioning.Firstly,we discuss a method of forest fire recognition in visible-light imagery.There are four aspects to improve accuracy and remove uncertainty in fire recognition:(1)eliminating factors of interference such as road and sky with high brightness,red leaves,other colored objects and objects that are lit up at night,(2)excluding imaging for specific periods and azimuth angles for which interference phenomena repeatedly occur,(3)improving the thresholding method for determining the flame border in image processing by adjusting the threshold to the season,weather and region,and (4)integrating the visible-light image method with infrared image technology.Secondly,we examine infrared-image-based methods and approaches of improving the accuracy of forest fire recognition by combining the spectrum threshold with an object feature value such as the normalized difference vegetation index and excluding factors of disturbance such as interference signals,extreme weather and high-temperature animals.Thirdly,a method of visible analysis to enhance the accuracy of forest fire positioning is examined and realized;the method includes decreasing the visual angle,selecting central points,selecting the largest spots,and judging the selection of fire spots according to the central distance.Case studies are examined and the results are found to be satisfactory. | JIANG LiLi 1,QI QingWen 1,ZHANG An 1,GUO ChaoHui 2 & CHENG Xi 1,3 1 Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China 2 China Center for Resources Satellite Data and Applications,Beijing 100094,China 3Graduate University of Chinese Academy of Sciences,Beijing 100049,China | 2010 | Science China(Technological Sciences)2010，53，S1： | 9 |
| 20 | Ventilator management for acute respiratory distress syndrome associated with avian infl uenza A(H7N9) virus infection: A case series显示文摘BACKGROUND: Data on the mechanical ventilation(MV) characteristics and radiologic features for the cases with H7 N9-induced ARDS were still lacking.METHODS: We describe the MV characteristics and radiologic features of adult patients with ARDS due to microbiologically confirmed H7 N9 admitted to our ICU over a 3-month period.RESULTS: Eight patients(mean age 57.38±16.75; 5 male) were diagnosed with H7 N9 in the first quarter of 2014. All developed respiratory failure complicated by acute respiratory distress syndrome(ARDS), which required MV in ICU. The baseline APACHE II and SOFA score was 11.77±6.32 and 7.71±3.12. The overall CT scores of the patients was 247.68±34.28 and the range of CT scores was 196.3–294.7. The average MV days was 14.63±6.14, and 4 patients required additional rescue therapies for refractory hypoxemia. Despite these measures, 3 patients died.CONCLUSION: In H7 N9-infected patients with ARDS, low tidal volume strategy was the conventional mode. RM as one of rescue therapies to refractory hypoxemia in these patients with serious architectural distortion and high CT scores, which could cause further lung damage, may induce bad outcomes and requires serious consideration. Prone ventilation may improve mortality, and should be performed at the early stage of the disease, not as a rescue therapy. | Hui Xie Zhi-gang Zhou Wei Jin Cheng-bin Yuan Jiang Du Jian Lu Rui-lan Wang | 2018 | World Journal of Emergency Medicine2018，9，2： | 9 |
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