1,721,009 research outputs found
Ville et révolution architecture et urbanisme soviétiques des années vingt par Anatole Kopp ; Préface de I. Shein ; Editions Anthropos, 1967, 278 p. 30 p. d’annexes, bibliographie, 1
No full textLévy Catherine. Ville et révolution architecture et urbanisme soviétiques des années vingt par Anatole Kopp ; Préface de I. Shein ; Editions Anthropos, 1967, 278 p. 30 p. d’annexes, bibliographie, 1. In: Autogestion : études, débats, documents, N°4, 1967. pp. 174-176
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
Deformation and vibration of a spiral spring
No full text在本文中，使用空間彈性理論來分析渦旋彈簧的靜態變形與振動頻率，首先考慮圓形截面的渦旋彈簧，渦旋彈簧內外有兩端點，其中一端夾持於一固定端，另一端夾持在一可旋轉的圓形轉盤上。由靜態分析中可以得知，渦旋彈簧受扭轉一定角度之後，彈簧發生挫曲，形狀由平面變成三維變形。從扭力與旋轉角的關係圖中，可知彈簧會在轉兩圈後回到相同變形。在振動分析中，求得平面變形有平面及空間兩種模態振形，空間振動模態所相對應的自然頻率比平面振動模態所對應的自然頻率先下降至零，可以由此預測彈簧將以此模態振形發生空間變形。為驗證理論分析的正確性，本研究設計了一個初始圈數為五圈、圓形截面的渦旋彈簧，以及實驗機構，量測其扭力與旋轉角的關係與自然頻率，實驗結果與理論分析相符。接下來考慮矩形截面的渦旋彈簧，在扭力與旋轉角的關係圖中，可以看出矩形截面的長寬比不影響其平面變形曲線，但是會影響到發生挫曲時的旋轉角，以及空間變形曲線。最後，本論文利用振動法求出來的挫曲角度與矩形截面的長寬比的關係，也與前人利用平衡法的做出的結果做了比較。In this paper we use elastica theory to study the deformation and natural frequencies of a spiral spring. We first consider a spiral spring with circular cross section. Static analysis shows that the spring undergoes planar deformation first and buckles into spatial deformation at a bifurcation point. The load-deflection curve repeats itself after two full turns. Therefore, the spring returns to its initial shape after two full turns. The planar deformation has two types of mode shapes; i.e., in-plane and out-of-plane. If one proceeds from initial shape to the bifurcation point, the natural frequency of one of the out-of-plane modes reduces to zero. This out-of-plane mode shape will be the buckling mode when planar deformation buckles into spatial deformation. Experiments are conducted on a custom made spiral spring with circular cross section. The measured deformations and natural frequencies agree with theoretical predictions very well. We next proceed to consider a spiral spring with rectangular cross section. It is found that the planar deformation is independent of the stiffness ratio between the two principal directions of the cross section. However, the spatial deformation and the bifurcation point depend on the stiffness ratio. Finally, the relation between the critical angle and the stiffness ratio is obtained via vibration method and compared with previous work of others based on equilibrium method.第一章 導論 1
第二章 理論模型與控制方程式 3
2.1 彈性圓桿理論模型 3
2.2 控制方程式推導過程 4
第三章 靜態變形分析 7
第四章 振動分析 10
第五章 受力和位移關係圖 14
第六章 自然頻率與振動模態 16
6.1 控制位置 16
6.2 控制扭力 17
第七章 實驗設計與量測 19
7.1 實驗設備 19
7.2 扭力與旋轉角量測 20
7.3 自然頻率量測 21
第八章 不同初始圈數與不同截面的影響 23
第九章 結論 26
參考文獻 28
附錄I 靜態分析求解之純量方程式 57
附錄II 振動分析求解之純量方程式 61
附錄III 廣義應變向量 67
附錄IV N=3截面為圓形的渦旋彈簧 6
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
