1,721,129 research outputs found
Information Dynamics in Complex Networks
No full text節點間的通訊一直是網路中不可或缺的重要功能。為了實現資料傳遞於當今的通訊網路與社群網路，網路中的資訊動態扮演了一個非常關鍵的角色。尤有甚者，不同網路間複雜的鏈結使得整體網路趨向於一個更為龐大的複雜網路。雖然當今的通訊技術得利於複雜網路中的多元鏈結，但同時這些異質且具有相互影響性的鏈結也為資訊傳遞帶來了新的挑戰，例如資訊散佈的動態建模與控制、網路節點的攻擊與防禦及系統資訊傳輸效能的最佳化等。
在此論文中，我們運用統計物理的特性及疾病學的原理建立資訊傳播動態的數學模型。此數學模型提供了理論基礎以利於制定複雜網路中訊息傳輸的最佳控制方式。除此之外，考量複雜網路的網路拓樸特性，本論文分析了複雜網路的可靠度並提出了有效的網路防禦機制以提升網路的整體穩定性。基於我們對於複雜網路的建模以及分析，我們運用網路編碼設計一種嶄新的多路徑傳輸方式於多重跳躍式網路以提供傳輸速率與延遲的權衡與最佳化。本研究因此奠定了資訊動態於複雜網路中之理論分析基礎，並可應用於系統資訊傳輸效能提升、訊息傳遞控制與網路可靠性評估等研究領域。Information dynamics play an essential role to facilitate data transportation in modern communication networks as well as social networks. The complicated connections between these networks render them a complex communication network. Although modern technologies benefit from the diverse links in the complex network, in the meanwhile the heterogeneous and interdependent links incur new and challenging issues regarding information dissemination in the complex communication network, such as the information propagation process, the control of information dissemination, the attack and defense in the network and the optimization of rate-delay tradeoffs, to name a few.
In this thesis, we provide a primer on the information dissemination dynamics with the aid of epidemiology, which offers analytically tractable model to determine the optimal control policy for message passing in complex communication networks. Considering the topological attributes of the complex communication network, we analyze the network vulnerability and propose an efficient defense mechanism to enhance the network robustness. Based on the knowledge of complex network, we devise a novel multipath transmission scheme via network coding for rate-delay optimization in multihop networks. This research therefore lays the foundation of information dynamics in complex communication networks for system throughput enhancement, message passing control and network robustness assessment
A Study of Some Stochastic Models for Reservoir Planning
No full text 針對水庫規劃問題，包括水庫容量規劃或是最佳操作分析，有許多模式提出來，在此對二類共四個水庫規劃模式作探討。文中首先說明確定性的線性供水規則下水庫容量規劃模式，若利用其位勢網絡圖，能以高效率的演算來求解水庫規劃問題。然後探討機遇限制性的線性供水規則下水庫容量規劃模式，考慮在ㄧ定可靠度進水量下的水庫最小容量問題，它可利用一般的線性規劃求解，但是本文將原機遇限制性模式轉換到上述位勢網絡模式，故可用高效率的位勢網絡法來求解。 另一類模式是馬可夫決策模式，根據不同的狀態變數與進水資料機率，可有不同類型，本文介紹其中二種。它們皆考慮水庫的最大收益或是最小成本，以決定其最佳操作。本文以動態規劃、策略迭代法與線性規劃三個方法求解其中一模式的案例。 最後，以確定性與機率限制性兩線性供水規則下水庫容量規劃模式應用於明德水庫，並利用位勢網絡法求解機遇限制性模式，其結果不僅相近且效率非常高。Four models for analysis of reservoir capacity or operation are studied. Two models, both with an incorporated linear decision rule, are for the preliminary estimation of required reservoir capacity. One of these two models is deterministic while the other is chance-constrained. The latter can be converted to the former and solved by an efficient potential network. he other two of the four models are for the cost-effective operations of reservoirs. Both models are in the form of Markovian decision process, but the state variables and the streamflow probabilities are treated differently.he first two models are applied in the reliability analysis of capacity.of MinTeh reservoir.摘要…………………………………………………………………Ⅰbstract………………………………………………………………Ⅱ目錄…………………………………………………………………Ⅲ目錄………………………………………………………………………Ⅴ目錄…………………………………………………………Ⅵ一章 序論 1.1 前言 1.2 研究目的 1.3 文獻回顧 2二章 線性供水規則下水庫容量規劃模式 3.1 功能需求條件 3.2 水量收支條件與供水決策規則 5.3 線性供水規則下水庫容量規劃模式 6.4 單純容量模式位勢網絡圖 6.5 位勢網絡高程演算程序 10.6 簡例 10三章 線性供水規則下機遇限制性水庫容量規劃模式 14.1 機遇限制式 14.2 操作條件 14.3 機遇限制性規劃模式 15.4 機遇限制式的轉換 18.5 簡例 18四章 馬可夫決策模式(一) Markov Decision Model(Ⅰ) 23.1 單功能水庫問題 25.2 放水方案和放水策略 25.3 遞移機率 26.4 缺額成本 27.5 有限時段動態規劃問題 28.6 折扣因子 31.7 期望折扣成本 31.8 策略窮舉法 34.9 策略迭代法 35.10 線性規劃法 37五章 馬可夫決策模式(二) Markov Decision Model(Ⅱ) 40.1 水庫操作模式 40.2 水庫運轉N年的總成本 42六章 應用案例-明德水庫 52.1 線性供水規則下水庫容量規劃模式 53.2 線性供水規則下機遇限制性水庫容量規劃模式 56.3 結果與討論 57七章 結論與建議 75.1 結論 75.2 建議 75考文獻…………………………………………………………77錄 Moran Model……………………………………………………7
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A university map of course knowledge
Get PDFKnowledge representation has gained in relevance as data from the ubiquitous digitization of behaviors amass and academia and industry seek methods to understand and reason about the information they encode. Success in this pursuit has emerged with data from natural language, where skip-grams and other linear connectionist models of distributed representation have surfaced scrutable relational structures which have also served as artifacts of anthropological interest. Natural language is, however, only a fraction of the big data deluge. Here we show that latent semantic structure can be informed by behavioral data and that domain knowledge can be extracted from this structure through visualization and a novel mapping of the text descriptions of elements onto this behaviorally informed representation. In this study, we use the course enrollment histories of 124,000 students at a public university to learn vector representations of its courses. From these course selection informed representations, a notable 88% of course attribute information was recovered, as well as 40% of course relationships constructed from prior domain knowledge and evaluated by analogy (e.g., Math 1B is to Honors Math 1B as Physics 7B is to Honors Physics 7B). To aid in interpretation of the learned structure, we create a semantic interpolation, translating course vectors to a bag-of-words of their respective catalog descriptions via regression. We find that representations learned from enrollment histories resolved courses to a level of semantic fidelity exceeding that of their catalog descriptions, revealing nuanced content differences between similar courses, as well as accurately describing departments the dataset had no course descriptions for. We end with a discussion of the possible mechanisms by which this semantic structure may be informed and implications for the nascent research and practice of data science
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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