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建立臺灣地區半動態基準之水平速度場與變形模型研究 / The Study of Establishing Horizontal Velocity and Deformation Model of Semi-Dynamic Datum in Taiwan Area熊育賢, Hsiung, Yu Hsien Unknown Date (has links)
國家坐標系統是各項測量作業的基礎,而大地基準的選擇及建立更是會直接影響最後的測量成果,進一步的影響各項國家建設、民生工業以及人民的土地財產等權益。板塊運動之中尤其是非線性的板塊運動更是會改變坐標框架中參考站的相對位置,隨著時間的推移進而導致框架的幾何精度下降。而臺灣地處歐亞板塊及菲律賓海板塊的交界處,頻繁的板塊運動會造成地震、火山以及其他的自然災害,且臺灣各個區域也會因為板塊間的非線性運動而往不同的方向旋轉、位移。目前臺灣使用的坐標系統為TWD97 (Taiwan Datum 97 ),是建立於一個固定的線性框架ITRF94(The International Terrestrial Reference Frame 94)下之靜態基準,因此並不能精確的表達臺灣地區複雜的地殼變動情形,臺灣需要進行大地基準的革新以解決坐標框架變形之問題,即是在原有的靜態基準加上速度場與變形模型來改正因地殼運動造成之坐標偏移。本研究利用 2005 年至 2015 年間之臺灣地區連續運行參考站 GPS 觀測資料計算臺灣地區水平速度場情形,並參考日本、紐西蘭等國之速度模型建立方式,以內插、曲面擬合、局部加權回歸散點平滑等方法建立臺灣地區水平速度與變形模型。而臺灣地區參考站坐標解算之水平精度為 2mm-3mm、高程精度為 6mm-10mm,而速度場之年度平均標準差在 N 軸為 3.81mm,E 軸為 5.18mm。水平速度場模型方面以內插法中的線性及三次樣條內插法建立之模型有最好的精度,另外透過變形模型可以有效將地震之同震位移對坐標預測之影響消除,使速度模型之使用年限得以延長。 / National coordinate system is the foundation of surveying engineering, the establishment and the selection of geodetic datum would directly impact the accuracy of final result. Plate motion will cause earthquakes, volcanic eruptions and other natural disasters. Plate motion especially non-linear motion can also change the relationship between stations in the reference frame. Therefore, a rational and reliable reference frame is needed to ensure the Euclidean integrity quality. Taiwan is located along the bounding of the Eurasian and the Philippine plate, and is therefore a region of non-rigid motion and therefore will shift and rotate in different directions due to the changing stress field. Taiwan’s current coordinate system TWD97 is built by a fixed single term linear model ITRF94. It is not able to precisely model the non-linear motion of the crustal in the Taiwan region. Therefore, Taiwan needs velocity and deformation model to correct the distortion which caused by the crustal motion. This study used 11 years of Taiwan CORS GPS data to investigate the horizontal velocity field in Taiwan and established the horizontal velocity and deformation model by curve fitting, interpolation and LOWESS method. The horizontal coordinate accuracy of the stations is about 2mm-3mm, the vertical accuracy is about 6mm-10mm, and the average standard deviation of velocity field is 3.81mm in N axis, 5.18mm in E axis. As for velocity model, linear and cubic spline interpolations have better model accuracy. In addition, the deformation model can effectively eliminate the influence of coseismic deformation, so that the velocity model will not lose its utility.
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Analysis of Oauth and CORS vulnerabilities in the wildArshad, Elham 06 December 2022 (has links)
Thanks to the wide range of features offered by the World Wide Web (WWW), many web applications have been published and developed through different libraries and programming languages. Adapting to new changes, the Web quickly evolved into a complex ecosystem, introducing many security problems to its users. To solve these problems, instead of re-designing the Web, the vendors added the security patches (protocols, mechanisms)to the Web platform to provide a more convenient and more secure environment for web users.
However, not only did these patches not completely resolve the security problems, but their implementations also introduced other security risks unbeknownst to website operators and users.
In this thesis, I propose a novel research on two different security patches to understand and analyze their deployment in real-world scenarios and discover the unseen, neglected factors and the elements involved in exploiting their use: one security protocol, OAuth, and one security mechanism, CORS.
As this thesis is based on offensive approaches, I develop automated methodologies, including novel strategies for analyzing and measuring the security qualities of the OAuth protocol and CORS mechanism in real-world scenarios.
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Tropospheric Delay Modeling using GNSS Observations from Continuously Operating Reference Stations (CORS)alojaiman, shahad N M A A January 2019 (has links)
No description available.
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An assessment of the GPS L5 signal based on multiple vendor receiversSmyers, Serena Ashley 21 February 2012 (has links)
The L5 signal of the Global Positioning System (GPS) is becoming available on an increasing number of Block IIF satellites. As the third civilian signal, L5 is superior in signal design to the L1 C/A and L2C civilian signals. This new signal has been marked healthy for use on selected satellites since 2010, yet the hardware capable of tracking the L5 signal is still in the early stages of development. This work investigates the characteristics of the new signal and the quality of data produced by L5-tracking receivers. Commonly used receiver models chosen for this study are the Leica GRX1200+GNSS, the Trimble NetR8, and the Javad Delta TRE-G3TH. The metrics used in this analysis to assess the quality of data produced by these receivers are signal strength, receiver phase noise, receiver code noise, and multipath. The data used in these analyses were obtained from the International GNSS Service for the days of the year 275 to 281 in 2011. Metrics averaged over the GPS week 1656 provide a good indication of the overall performance of the receivers. / text
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Site-Specific Point Positioning and GPS Code Multipath Parameterization and PredictionEDWARDS, KARLA ROBERTA LISA 25 October 2011 (has links)
No description available.
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