1,720,988 research outputs found
Design of Underwater Impedance Tube for the Measurement of Material Acoustic Characteristics
No full text本文旨在設計及製作一個專門用來量測水下吸音材的量測系統，藉此可以量測不同材料的聲學參數，例如反射係數、正向入射吸收係數、以及特殊音響阻抗比等。其免除了以往如迴響室等龐大硬體工程的建造，在價錢上較為低廉，機動性也較高。
首先，根據ASTM設計規範為阻抗管之設計準則，進而配合波導管平面波傳理論設計出不同管徑的阻抗管各一組。其次，為了測試阻抗管的可用性，利用轉換函數法針對所需之實驗配置經由不斷的測試來證明如此的設計是否可行。再者由於管壁的剛性與否，將會影響到波導管的波傳模態，所以我們加以配合彈性波導管理論，進而求出其模態頻散曲線以及質點位移分佈圖，進一步的比較剛性與彈性波導管之差異。這些被量測到的特性可用於基本研究和發展吸音材，並可供學術界相關研究作參考。The thesis mainly discusses the design and fabrication of underwater impedance tube for the measurement of material acoustic characteristic. This test method can be applied to measure sound reflection coefficient, normal incidence sound absorption coefficient and specific acoustic impedance ratio of materials.
Firstly, the impedance tubes of different sizes are made according to ASTM standards and the theory of plane wave propagation. Then the theory of a transfer function method of measuring normal incident in-duct acoustic properties is presented. However, the elastic moduli and density of the tube wall and the fluid are often of similar magnitudes, and the rigid wall approximation is invalid. As a result, for example, the plane-wave mode characteristic of the rigid wall waveguide degenerates to a mode with phase velocity somewhat slower than the intrinsic sound velocity. So we study the two (ET0 and ET1) low-frequency axisymmetric propagation modes in the liquid-filled elastic tube waveguide and it is be shown for numerical calculations of modal dispersion curves and particle displacements. The properties measured with this test method are useful in basic research and product development of sound absorptive materials.摘要…………………………………………….……………………….Ⅰ
目錄……………………………………………………………………..Ⅲ
附圖目錄………………………………………………………………..Ⅴ
符號說明………………………………………………………………..Ⅷ
第一章 緒 論
1-1 前 言……………………………………………………………...1
1-2 文獻回顧…………………………………………………………..2
1-3 研究目的與方法…………………………………………………..3
第二章 阻抗管之元件設計與量測方法
2-1 元件設計規範……………………………………………………..5
2-1-1 管子………………………………………………………...5
2-1-2 測試樣品支撐架…………………………………………...7
2-1-3 聲源………………………………………………………...8
2-1-4 水聽器……………………………………………………...8
2-1-5 測試樣品……………………………..…..……………….9
2-2 轉換函數………………...………………………………………10
2-3 轉換函數校正量測……………….……………………………..12
2-4 轉換函數與正向反射係數之關係…………..………………….13
第三章 圓柱形彈性波導管之理論模擬分析
3-1 模態頻散曲線關係…………………………………...…………17
3-2 質點振動位移關係……………………………...………………21
3-3 平面波運動之材料選擇與管徑最佳化設計…………………...23
3-4 不同管徑與材料之模擬計算結果比較………………………...24
第四章 阻抗管量測結果分析
4-1 實驗背景描述…………………………………………………...51
4-2 實驗儀器配置…………………………………………………...53
4-3 量測結果分析………………………………………………...…55
第五章 結論與未來研究方向
5-1 結論……………………………………………………………...62
5-2 未來研究方向…………………………………………………...65
參考文獻……………………………………………………………….6
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
Evaluation of HIV Case Management and Strengthened Partner Service Program
No full text背景： 國內愛滋病毒感染人數逐年增加，公共衛生人員個案管理及伴侶服務的負擔日益沉重，然而我國伴侶服務完成率亦亟待提升，有鑑於此，疾病管制署於2013年至2014年委託臺灣愛滋病護理學會於新北市試辦「愛滋個案管理和加強型伴侶服務試辦計畫」，以建構有效之公衛端愛滋病個案管理模式，提升個案管理品質並減輕公衛人員負擔。目前國內多數研究僅針對愛滋病指定醫院辦理之愛滋病個案管理師計畫進行評估，而試辦計畫對於提高就醫率及伴侶服務完成率之成效，亟待進一步探討。 目的： 探討「愛滋個案管理和加強型伴侶服務試辦計畫」的介入，對於HIV感染者之完成伴侶服務及就醫情形之影響 方法： 本研究採取僅有後測之對照組設計(The comparison group posttest-only)設計方式，以「慢性傳染病追蹤管理－愛滋及漢生病子系統」資料庫為研究工具，並以2011年至2014年間全國確診人類免疫缺乏病毒感染個案為研究對象，依個案之確診年份及管理縣市，區分為介入組、新北市對照組及其他縣市對照組，採邏輯斯迴歸及考克斯比例風險模式分析方式，藉以檢視試辦計畫提升個案診斷後完成伴侶服務及就醫之成效。 結果： 研究結果發現，介入組之診斷後4個月內伴侶服務完成率為18.4%，顯著高於新北市對照組的9.5% (p<.0001)及其他縣市對照組的10.3% (p<.0001)，在使用多變項分析調整其他影響因素的作用後，介入組相較於新北市對照組，有較高的機會於診斷後完成伴侶服務(OR=2.3, p<.0001; HR=1.625, p<.0001)。 結論： 試辦計畫之介入，使診斷後完成伴侶服務之比例有顯著且正向之提升，顯示委託民間專業護理團體介入之愛滋個案管理模式，能整合醫院、公衛、社會等資源，使介入措施及服務能有效率的輸送，進而顯著提升伴侶服務之完成情形。Background： The number of domestic HIV infection increases every year, therefore, the burden of case management and partner services of public health workers increases accordingly. Since the completion rate of partner service needs to be enhanced, Taiwan Centers for Diseases Control commissioned Taiwan AIDS Nurses Association a pilot program “HIV Case Management and Strengthened Partner Service Program” to implemente in New Taipei City during 2013 and 2014. The goal of this pilot program is to construct effective HIV case management model in public health and to enhance the quality of case management. At present, most domestic research only focus on HIV Case Management Program in the designated HIV hospitals, the medical rates and completion rates of partner services of the polit program needs to be further evaluated. Objectives： Evaluate the intervention of “HIV Case Management and Strengthened Partner Service Program” on the completion rates of the partner services and rates of seeking medical care in HIV-infected persons. Methods： This evaluation research applies a comparison group posttest-only design. This research uses database of “Chronic infectious diseases case management system"" as a research tool. Only HIV-infected persons diagnosed during the period from 2011 to 2014 were included in this research. According to year of diagnosis and county of management, we selected two control group: New Taipei Comparision Group and Other Cities and Counties Comparsion Group to compare with Intervention Group. Logistic regression and Cox proportional hazards model analytical methods were conducted to assess the program impact. Results： Completion rate of partner service within 4 months is 18.4% in Intervention Group,which is higher than New Taipei Comparision Group (9.5%, p<.0001) and Other City and County Comparsion Group (10.3%, p<.0001). Mutivariate analysis through Logistic regression and Cox proportional hazards model indicated that Intervention Group has higher chance to complete partner service than New Taipei City Comparison Group (OR=2.294, p<.0001; HR=1.625, p<.0001). Conclusion： The Intervetion Group has shown significant positive effects on completion rate of partner services after HIV diagnosis. The CBO (Community-Based Organisations) partner service model provided by HIV professional organization could integrate intervention with hospital, local health department and social resources to futher enhance the completion rate of partner services of HIV infected person
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
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