由於車載網路的緊急訊息傳送對於現今智慧通訊系統的發展是很重要的,因 此現今有許多文獻針對緊急訊息傳送做探討,而本論文提出一個嵌入的馬可夫 鏈模型去分析在稀疏車載網路的儲存攜帶轉送傳遞訊息的穩態行為。根據前一 次網路斷開被修復時的車輛位置去討論此次網路斷開會在何種狀態下被對向車 輛修復,根據對向車輛與訊息傳遞車輛的相對位置可分成三種類型類型一(Λ1)、
類型二(Λ2)與類型三(Λ3),而各種類型大致上可分為兩種狀態,分別是修復網路 斷開之對向車輛不需移動即可修復網路斷開的狀態Π0與對向車輛需經過移動才 可修復網路斷開的狀態ΠK,另外,在Π0需考慮修復網路斷開之對向車輛所在的 叢集大小,而ΠK需考慮修復網路斷開之對向車輛與其前車之距離,這是由於車 輛若是需要移動表示訊息已傳送至叢集之最前方車輛仍無法修復網路斷開,因 此修復網路斷開之車輛必定為叢集之最前方的車輛。在各狀態下又可依據訊息 來源端車輛後方傳輸範圍內是否有對向車輛可將狀態在細分為事件一(Γ𝐿)與事件 二(Γ𝑅)。
根據提出的數學模型計算出所要求的三樣東西,分別為利用對向車輛修復網 路斷開所需花費的延遲時間、對向車輛不需移動即可修復網路斷開的機率,以 及修復網路斷開之對向車輛與前車的距離,使用對向車輛不需移動即可修復網 路斷開的機率與修復網路斷開之對向車輛與前車的距離可求出前一次網路斷開 在 m 狀態下此次進入 n 狀態下的轉換機率,進而求出穩態機率。以及從利用對 向車輛修復網路斷開所需花費的延遲時間可算出延遲時間的平均值與變異數。
數值分析的結果顯示我們所提出的穩態機率分析是高度準確的,並且可以觀 察到長期會發生的狀態,而本論文所提出的方法計算出之延遲時間的平均值與 變異數比起過去的文獻也更加接近模擬,這是因為本論文所提出的分析有考慮 到前一次的網路修復對此次的影響,並且還求出了穩態機率可以觀察出長期呃 狀態。在未來的研究中,希望可以加上多個網路斷開的分析,使研究更加接近 真實的情況。
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自 傳
的想法然後實踐,在這個過程中溝通是很重要的;而在活動執行中,要隨時注 意現場狀況來因應參與者的需求做及時的反應,因此在整個過程中,從準備到 執行學習到很多,在完成活動時也獲得了成就感。而在參與活動的過程中,也 沒有忽略課業,在學習的過程中,和高中不同,不僅有理論,也在實驗課中驗 證了理論,而在慢慢適應了大學生活後,成績也慢慢的進步。
因為申請了學校的 4+1,因此繼續留在國立臺灣師範大學電機工程學系研究 所學習,在成為研究生的生活中,明顯的感受到研究所與大學的不同,在指導 教授的協助下,慢慢培養出研究生所需具備的能力。
學術成就
1.
論文發表(1) Jeng-Ji Huang, Yu-Ting Tseng “Steady State Probability for Store-Carry-Forward Message Delivery in Sparse VANETs”, ICFUN 2016
(2) Jeng-Ji Huang, Po-Chun Shen, Yu-Ting Tseng “Enhancing performance of feedback-Based QoS scheduling for video delivery over WLANs”, Computer Communications 2016, July, 2016