Status Sequences and Branch-Weight Sequences of Trees

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/7781

Title:	Status Sequences and Branch-Weight Sequences of Trees
Authors:	商珍綾;Jen-Ling Shang
Contributors:	數學研究所
Keywords:	Trees;Status;Branch-Weight Sequences;Sequences
Date:	2005-06-20
Issue Date:	2009-09-22 11:05:15 (UTC+8)
Publisher:	國立中央大學圖書館
Abstract:	關於圖( graph)的研究，圖中資料形成的數列(sequence)，經常提供了明確的數據，讓研究者得以一窺圖所蘊涵的道理。數列提供的是一個圖對於某些性質的整體表現，它往往比單一的數值更有意義，更適合作為思考與猜測的憑藉。因此，根據圖中數列透露出的訊息來研究圖的方法，長久以來廣泛的受到重視與使用。本篇論文共分為五章，第一章介紹相關的定義及文章。B. Zelinka (1968, [Zel])證明了對於任意一個樹(tree)，它的median與centroid是相同的。A. Kang與D. Ault (1975, [Kang])則證明了若是將樹的邊(edge)加上權重(weight)，此結論亦真。第二章中，2-1節裡，我們獲得了圖中關於status與branch-weight的許多性質，並將上述的結論加以推廣，得到了對任意一個有權重的樹(a weighted tree , 即對所有邊與點(vertex)都賦予權重的樹)，它的median恆與centroid相同。2-2節裡，我們證明了對於任意一個所有邊的權重皆為1的有權重的樹，其second median恆與second centoid相同。第三章中，我們給予了樹中status數列的一些性質，而其主要結論為，若是一個樹與一個蜘蛛(spider)有相同的status數列，則它們是相同的(they are isomorphic)。第四章中,在4-1章節裡，我們給予了許多例子，來觀察不同性質的樹之status數列。4-2節得到了一個主要結論，一個樹若與另一個weakly status-injective的樹有相同的status數列，則它們是相同的。第五章中，在5-1節裡，我們給予了許多不相同的(nonisomorphic trees)卻具有相同的branch-weight數列的例子。5-2節裡，我們介紹了如何由一個蜘蛛所產生的branch-weight數列，重新將這個唯一的蜘蛛構造出來的方法，從而產生了主要的定理，如果有兩個蜘蛛有相同的branch-weight數列，則它們是相同的。 Abstract B. Zelinka [Zel] showed that the median of any tree is equal to its centroid. A. Kang and D. Ault [Kang] extended this result for any tree with weights on its edges. In Chapter 2, we extend the result further to any tree with weights on its edges and vertices and show that the second median of any tree with weights on its vertices is equal to its second centroid. The main result in Chapter 3 is that if S is a spider, T is a tree and S , T have the same status sequence,than S is isomorphic to T . In Chapter 4, we show that if T is a weakly status-injective tree, T' is a tree, and T ,T' have thesame status sequence, then T is isomorphic to T'. The main result in Chapter 5 is that if two spiders have the same branch-weight-sequence, then they are isomorphic.
Appears in Collections:	[Graduate Institute of Mathematics] Electronic Thesis & Dissertation

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