1,720,965 research outputs found
Feasibility Study on Building Mass Damper Using Optimum Dynamic Response Control Algorithm for Practical Application
No full text近年來隨著隔震設計之建築物蓬勃發展，其中基礎隔震設計須於基礎進行繁瑣伸縮縫施工，因此考量施工性較優之中間層隔震設計逐漸被廣泛應用，然而中間層隔震設計之高模態參與比例較高，恐造成隔震層下部結構反應放大。欲減少隔震層下部反應放大的問題，考慮傳統調諧質量阻尼系統為一有效之振動能量吸收器，其基本原理將調諧質量阻尼系統之自然頻率調整趨近於主要系統，使兩者於外力作用下產生反相位運動進而以調諧質量阻尼器消散外力擾動能量。 自體調諧質量阻尼(Building Mass Damper，BMD)系統將上部結構視為調諧質量，並利用橡膠支承墊與黏性阻尼器分別提供BMD系統所需之勁度及阻尼，結合中間層隔震與調諧質量阻尼器設計之優點，同時控制下部與上部結構反應。數值模型上，以一簡化三自由度模型分別模擬上部結構、控制層及下部結構，進而以三自由度之動力反應總和最小化作為控制目標，推導BMD最佳化系統參數。 基於前導研究已分別透過數值模擬及振動台實驗，驗證BMD設計於八層樓縮尺構架之可行性，故本研究將針對BMD設計於實際結構之可行性進行探討，因此將採用57層樓鋼構架作為空構架設計依據，在分析程序上，先根據2%鋼構架初始阻尼比分別設計TMD、BMD及OBMD構架，透過歷時分析上輸入六組不同特性之地震歷時，比較三種不同減震設計法之歷時反應，同時透過簡化三自由度之加速度轉換函數配合震波FFT頻涵圖，交互驗證其歷時行為；根據第一階段之歷時分析結論，分別設計一主結構阻尼比為4%之OBMD構架，以及一整體阻尼比為4%之消能減震構架，並重新對於空構架、消能減震構架及OBMD構架進行歷時分析，最後分別對於最大層間變位角及樓層最大加速度進行結果比較，以總結出BMD設計於實際案例應用之可行性。In a mid-story isolated building, the isolation system is incorporated into the mid-story rather than the base of the building. The effectiveness of mid-story isolation design in reducing seismic demands on the superstructure above the isolation system has been verified in many researches. But the response of substructure may be enlarged due to the flexibility and the contribution of the higher modes. Besides, tuned mass damper (TMD) system has been recognized as an effective energy absorbing device to reduce the undesirable vibrations of the attached vibrating system subjected to harmonic excitations. Therefore, the concept of building mass damper (BMD) design is to combine the tuned mass damper system and mid-story isolated design to control the seismic response of both substructure and superstructure. In BMD design, the superstructure serves as a tuned absorber mass whose stiffness and damping can be provided by the isolation system composed of elastomeric bearings and additional dampers, as the advantages of conventional tuned mass damper and mid-story isolation systems can be integrated. A simplified three-lumped-mass structure model, in which three lumped masses are respectively assigned at the building mass absorber, the control layer, and the primary structure, is rationally assumed to represent a building structure with a BMD system. The reason for doing this is so that the inherent dynamic characteristics (fundamental modal characteristics of vibration) of both the building mass absorber and the primary structure can be considered comprehensively in the simplified structure model. The feasibility of the optimum BMD (or OBMD) design method has been verified in previous studies. In this research, the 57-story steel frame is used to be a bare frame. According to 2% inherent damping ratios of the TMD, BMD and OBMD can be designed respectively. Six real earthquake records with distinct seismic characteristics adopted in this research are selected for the ground acceleration inputs along the longitudinal and transversal direction. On the other hand, the acceleration transfer functions of the simplified three-lumped-mass structural model and the FFT of each ground motion are used to describe the seismic behavior of the TMD, BMD and OBMD. Then, the seismic responses of the OBMD system are thoroughly investigated and the practicability and effectiveness of the OBMD system for seismic design are verified
Nuclear condensation and cell cycle arrest induced by telomerase siRNA in neuroblastoma cells
No full textNeuroblastoma is a type of malignant extracranial tumor that occurs in children. Advanced neuroblastoma, and tumors with MYCN amplification in particular, have poor prognoses. Therefore, it is important to find an effective cure for this disease. Small interfering RNA (siRNA) disrupts gene function by specifically binding to target mRNA. In this study, we used siRNA against telomerase to treat neuroblastoma, to evaluate any anti-proliferative effect on these cells. We evaluated cell viability by WST-1 assay on neuroblastoma cells treated with or without telomerase siRNA. Nuclear condensation, an indicator for apoptotic cells, was determined by DAPI labeling following siRNA treatment. The effectiveness of telomerase siRNA on altering the neuroblastoma cell cycle was detected by flow cytometry. Our results indicated that telomerase siRNA reduces the viability of neuroblastoma cells and increases the percentage of cells in the cell cycle's sub-G1 phase. We found that telomerase siRNA increases the percentage of condensed DNA in neuroblastoma cells. In conclusion, using siRNA against telomerase could be further developed as a therapy for the treatment of neuroblastoma
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
[[alternative]]The first year teacher.
No full text[[abstract]]本研究的目的在瞭解幼稚園初任教師專業成長之歷程。研究中以選取兩位公立幼稚園初任教師為研究對象。研究方法是運用訪談，輔以直接觀察和蒐集相關資料的方式。資料經過分析、歸類、統整之後，將研究發現分為人際關係、班級經營和課程與教學三部份。一、人際關係 維芝老師沒有得到搭檔黃老師很多的幫助，因此適應環境的過程比較緩慢；而怡君老師得到搭檔高老師的協助，比較快適應環境。維芝老師和其它同事的相處非常融洽；而怡君老師幼稚園中有些老師間相處的不太和諧。在家長溝通和小朋友之間的相處方面，兩位老師都隨著時間及經驗，將彼此關係處理得愈來愈好。二、班級經營對初任教師來說，班級經營是相當具有挑戰性的。維芝老師較注重孩子的行為輔導，怡君老師則較注重孩子之間的個別差異，在這一部份他們仍在努力中。三、課程與教學對兩位初任老師來說，第一年的課程設計和教學活動的實施，都在嘗試的階段；而隨著時間及經驗的累積，兩位老師在教學資源的運用及時間的安排上漸上軌道。研究結果顯示，初任教第一年，教師的關注點在於自己是否能生存？是否能與搭檔合作愉快？是否幼兒回聽他們的話？而較少關注於課程教學上。這兩位個案雖然面臨的問題不盡相同，我們可以發現有好的搭檔來配合教學，的確可以使初任教師在教學過程中有良好的適應。綜合研究結果，提出以下建議：一、透過多種管道提供初任教師所需的協助。二、加強初任教師人際溝通能力，增進同事間的良好關係。三、提昇初任教師自覺能力，並協助以反省教學，增進專業成長。四、公立附設幼稚園的行政獨立，老師不擔任小學的行政工作。五、搭班老師合作前，應有事先的互相認識。六、初任教師要有虛心學習的態度。本研究提供幼稚園初任教師專業成長之歷程，以提供師資培育機構和初任教師參考。
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