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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

旋翼UAS影像密匹配建物點雲自動分群之研究 / Automatic clustering of building point clouds from dense matching VTOL UAS images

林柔安, Lin, Jou An Unknown Date (has links)
三維城市模型之建置需求漸趨繁多,可提供都市規劃、城市導航及虛擬實境等相關應用,過去研究多以建置LOD2城市模型為主,且較著重於屋頂結構。近年來,逐漸利用垂直影像及傾斜影像作為原始資料,提供建物牆面之建置,並且,隨著無人機系統(Unmanned Aircraft System, UAS)發展,可利用其蒐集高解析度且高重疊垂直及傾斜拍攝之建物影像,並採影像密匹配技術產製高密度點雲,進而快速取得建物包含屋頂及牆面之三維資訊,而這些資訊可進一步提供後續建置LOD3建置層級之模型,而在建置前,首先須對資料進行特徵分析,萃取特徵點、線、面,進而提供建置模型所需之資訊。 因此,本研究期望利用密匹配點雲,計算其點雲特徵,並採用Mean Shift分群法(Comaniciu and Meer, 2002)萃取建物點雲資訊,並提供一最佳分群策略。首先,本研究將以UAS為載具,設計一野外率定場率定相機,並蒐集建物高重疊UAS影像密匹配產製高密度點雲,針對單棟建物高密度點雲,實驗測試點雲疏化程度後,依據疏化成果計算點雲特徵,並以此批點雲資料實驗測試Mean shift分群法(Cheng, 1995)中之參數,後設計分群流程以分離平面點群及曲面點群,探討分群成果以決定最佳分群策略。實驗結果顯示本研究提出之分群策略,可自動區分平面點群及曲面點群,並單獨將平面點群分群至各牆面。 / Unmanned Aerial System (UAS) offer several new possibilities in a wide range of applications. One example is the 3D reconstruction of buildings. In former times this was either restricted by earthbound vehicles to the reconstruction of facades or by air-borne sensors to generate only very coarse building models. UAS are able to observe the whole 3D scene and to capture images of the object of interest from completely different perspectives. Therefore, this study will use UAS to collected images of buildings and to generate point cloud from dense image matching for modeling buildings. In the proposed approach, this method computes principal orientations by PCA and identifies clusters by Mean shift clustering. Analyze the factors which can affect the clustering methods and try to decrease the use of threshold, and this result can cluster the façade of buildings automatically and offer the after building reconstruction for LOD3.
2

論美國武裝無人機的國際法問題 / On International law issues concerning U.S. armed UAVs

王正, Wang, Cheng Unknown Date (has links)
無人飛行載具或簡稱無人機是一種不實際搭載乘員的飛行裝置,不論研發的目的為何其核心概念皆是希望以機械來代替人力從事較為辛苦或較為危險的工作;歷史上記載無人機由來已久,但是類議題真正受到國際社會關切乃是2001年9月11日九一一事件後才開始。為了回應九一一事件對美國的威脅,美國除了以行使自衛權為由進攻阿富汗外,更發動了以全球伊斯蘭極端主義份子為對象的「全球反恐戰爭」並且開始大量投入武裝無人機執行定點攻擊行動,狙殺蓋達組織領導人或是與其有關聯的極端主義團體的成員。 隨著反恐戰爭的推進,美國派出的武裝無人機架次也逐年上升,隨之而來的是急遽上升的傷亡人數;驟增的傷亡數,尤其是平民傷亡引起了國際社會關切,其中「美國的武裝無人機攻擊是否違反國際法上關於武力使用的規範」成了急待解決的問題。本論文以當前國際法上關於武力使用的兩大規範:使用武力的合法性(Jus ad bellum)、武力使用的方式(Jus in bello)為途徑,檢視當前美國武裝無人機攻擊是否符合前述兩大規範,進而替美國武裝無人機攻擊衍生的國際法問題提供一個解答。
3

以四旋翼UAS酬載熱感測器製作數值表面溫度模型供地溫研究 / Generation of digital surface temperature model from images collected by thermal sensor on quadcopter UAS for geothermal study

謝耀震, Hsieh, Yao-Chen Unknown Date (has links)
熱像儀,能感測可見光感測器無法取得的訊息,因此若能透過熱像儀器進行環境偵測,便能得到一般可見光感測器無法獲取的資料。本研究擬以四旋翼UAS酬載熱像儀得到局部區域高解析度之地面熱資訊以便作為地溫研究之背景資料使用。而一般地溫研究區,不易佈設控制點,因此本研究除於無人機上酬載熱像儀之外,並將搭載Trimble BD970 GNSS OEM接收模組,嘗試以少量地面控制點、以及GNSS動態後處理的方式取得取像時對應的GNSS觀測量輔助熱像定位定向。本研究中針對國立政治大學旁的指南溪實驗區與陽明山國家公園的小油坑實驗區,使用AI-RIDER YJ-1000-HC四旋翼UAS分別酬載熱像儀FLIR Tau 640和巨哥XM6,並且同時搭載Trimble BD970 GNSS OEM接收模組、以及GNSS動態後處理的方式取得取像時對應的GNSS觀測量搭配少量地面控制點輔助熱像定位定向,過程中透過三焦張量剔除自動匹配之誤匹配連結點。實驗結果顯示,兩實驗區所產製之DSM於不易變動區域精度經現有資料檢核均在±1m,而指南溪實驗區產製出地面解析度11公分的數值表面模型(Digital Surface Model, DSM)與正射熱像,且正射熱像平面精度達為47公分;小油坑實驗區產製出地面解析度14公分之DSM與正射熱像,正射熱像平面精度則為67公分,雖然DSM和正射熱像精度無法符合一般常規的測量規範,但成果仍然可以證明熱像直接產製DSM以及正射熱像之可行性,兩實驗區最後皆生成數值溫度表面模型(Digital Surface Temparature Model, DSTM),顯示本研究所提方法之可行性,所生成之成果可供後續地溫研究使用。 / Thermal infrared images show the temperature change of sensed scenes. Therefore, thermal infrared camera can sense some important information that optical digital cameras cannot do for the environment monitoring. In this study, the Quadcopter UAS for thermal image collection applied to geothermal study will be developed. FIIR Tau 640 and Magnity Eletric XM6 thermal infrared sensor will be used in this thermal image collection system separately two test areas, Zhinan River nearby NCCU and Xiaoyoukeng, in the Yangmingshan National Park. Additionally, Trimble BD970 GNSS OEM board will be carried on the Quadcopter UAS to collect dual-frequency GNSS observations for determining the flying trajectory by Post-processed kinematic (PPK) technique to support the positioning and orientating of collected thermal images, and the trifocal tensor will be used to delete wrong matching tie images points. From the tests, the differences between produced DSM and existing DSM data are ± 1 m on uneasy change ground surface in two test areas. The resolution of produced DSM and thermal orthoimages are about 11 cm in Zhinan River, and 14cm in Xiaoyoukeng area. The accuracy of thermal orthoimages is 47cm in Zhinan River and 67cm in Xiaoyoukeng area. The accuracy of thermal orthoimages may not comply with a normal surveying standard, but it proves the possibility of DSM and orthorectifed thermal images generated from thermal images directly. Digital Surface Temparature Model (DSTM) produced in both tests can be used for volcanic geothermal monitoring in the future.

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