1,721,230 research outputs found
Tong ji hua he wu bo mo tai yang neng dian chi: xin tou ming dao dian dian ji yu que xian wu li
No full textYin, Ling = 銅基化合物薄膜太陽能電池 : 新透明導電電極與缺陷物理 / 尹苓.Thesis Ph.D. Chinese University of Hong Kong 2015.Includes bibliographical references.Abstracts also in Chinese.Title from PDF title page (viewed on 26, October, 2016).Yin, Ling = Tong ji hua he wu bo mo tai yang neng dian chi : xin tou ming dao dian dian ji yu que xian wu li / Yin Ling
Fabrication and characterization of e-beam photoresist array for biomimetic self-cleaning dry adhesives
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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
Predicting ectotherm vulnerability to climate warming: Comparing preferred and actual body temperatures in Pseudemoia entrecasteauxii
No full textInvestigation of the niche partitioning of selected Ranunculaceae species in Kosciuszko National Park along a soil moisture gradient, by comparison of hydraulic characteristics
No full textVariations 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
Performance Evaluation on Orthogonal Frequency Division Multiplexing System in Very High Mobility Environment
No full text在超高速的移動環境下，接收端易遭受到極大的都卜勒效應，系統遭受到的快速衰減影響相當大，傳統用的非時變通道傳送解調架構會造成錯誤率大幅提昇，因此針對了快速衰減影響我們在接收端用了針對時變通道效應而做的解調方式(ML通道估測或MMSE通道估測+時域通道內插改良+LMMSE等化器)來做效能評估，傳送端的領航符元分別使用梳狀跟塊狀排列方式傳送，在能夠忍受的錯誤率下計算出整體領航符元至少需擺放的比例，再跟傳統未考慮時變通道的接收端做比較。在高速鐵路的環境能夠利用各種部分已知的資訊，例如列車行進路線的可預測性、通道脈衝響應的各個多路徑延遲已知特性對運算量的簡化以及效能的提升，還有討論ML及MMSE通道估測的通道脈衝響應最長延遲格數設定有誤差時所造成的影響。In very high mobility environments, it is easy for the receiver to have large Doppler effects. The influence on the system caused by fast fading is very large. The traditional non-time-varying channels may increase bit error rate. According to fast fading channels, we use decoding methods aim at time-varying channels at receiver ( ML channel estimation or MMSE channel estimation + time-domain interpolation refinement + LMMSE equalizer ) to do performance evaluation. Pilot symbols at transmitter use comb type and block type to transmit. We compute overall pilot symbol ratios at least to transmit for tolerable bit error rate, and compare to traditional receiver which doesn’t consider time-varying channels. In high-speed trains environment, we can use partial known information, for example, predictability of progress routes of train, every multipath delay spread of channel impulse response known characteristics for the complexity reduction and the performance advance. Besides these, we also discuss channel impulse response longest delay spread grid of ML and MMSE channel estimation which sets inaccuracy to see the influence.口試委員會審定書………………………………………………………………………i
誌謝……………………………………………………………………………………iii
中文摘要………………………………………………………………………………v
英文摘要………………………………………………………………………………vii
第一章 緒論………………………………………………………………………..…1
1.1 前言……………………………………………………………………………1
1.2 研究動機………………………………………………………………………2
1.3 OFDM系統概述………………………………………………………………2
1.4 無線連結架構…………….…………………………………………………8
1.5 論文架構……………………………………………………………………13
第二章 時變通道環境傳送領航符元比例之分析…………………………………15
2.1 時變通道環境之通道估測與等化器之架構………………………………16
2.2 COST 259 模型簡介…………………………………………………………20
2.3 同調時間與同調頻寬計算…………………………………………………27
2.4 模擬環境的領航符元擺放方式……………………………………………29
2.5 模擬結果……………………………………………………………………30
2.6 討論…………………………………………………………………………34
2.7本章結論………………………………………………………………………35
第三章 時變通道環境使用MMSE通道估測並且與ML、非時變通道解調比較...37
3.1 時變通道環境使用MMSE通道估測………….……………………………37
3.2 模擬結果……………………………………………………………………38
3.3 MMSE通道估測與ML通道估測的比較……………………………………42
3.4 考慮時變通道解調MMSE通道估測與非時變通道解調的比較…………46
3.5 本章結論………………..……………………………………………………49
第四章 不同程度的部分通道已知資訊對效能的改善……………………………51
4.1 高速移動列車的行進路線已知(路徑已知)…………………………………51
4.2 通道脈衝響應的多路徑(multipath)數目不確定……………………………57
4.2.1 不知最長延遲分佈做通道脈衝響應估測…………………………57
4.2.2 ML通道估測做最長延遲分佈微調………………………………59
4.3 通道脈衝響應的各個多路徑延遲已知……………………………………62
4.3.1 原理與過程說明……………………………………………………62
4.3.2 複雜度與記憶體分析………………………………………………63
4.3.3 程式模擬結果………………………………………………………64
4.3.4 錯誤率改善原因分析………...………………………………………67
4.3.5 各路徑延遲已知與其他狀況比較…………………………………68
4.3.6 錯誤率被MLE反矩陣主宰或子載波間干擾主宰…………………72
4.4本章結論……………..………………………………………………………73
第五章 總結……………..…………………………………………………………….75
參考文獻……………………………………………………………………………..7
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
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