1,721,206 research outputs found
On the relations between subgroups of a group and submodules of modules over group rings
No full textLet R be a commutative ring and G a finite group. In [1], using a structure on an R module M to make it an RG module, we find some relations between RG submodules and a subgroups. We also prove that for each normal subgroup H of G with an invertible IHI in R, there is a direct summand RG submodule of M
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
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
Zero current switching rezonant switch converters
Full text linkBu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.Fen Bilimleri Enstitüsü, Elektrik-Elektronik Ana Bilim DalıIll ÖZET SIFIR AKIM ANAHTARLAMALI REZONANS ANAHTAR KONVERTÖRLER YÜCEL İbrahim Niğde Üniversitesi Fen Bilimleri Enstitüsü Elektrik-Elektronik Anabilim Dalı Danışman: Yrd. Doç. Dr. Mustafa ALKAN Eylül 1997, 76 sayfa Güç elektroniğinde anahtar olarak kullanılan yarı iletkenlerde, iletim ve anahtarlama kayıpları olarak iki tür kayıp bulunmaktadır. İletim kayıpları malzemenin yapısına bağlı olduğundan sonradan bu kayıpların azaltılması yönünde bir çalışma yapmak mümkün değildir. Fakat, anahtarlama kayıpları; anahtarlama frekansına, anahtardan geçen akıma ve anahtar üzerinde düşen gerilime bağlıdır. Dolayısıyla bu değerlerden herhangi birisinin sıfıra indirilmesiyle yarı iletken anahtarlarda oluşan darbeleme kayıpları sıfıra çekilebilir. Bu çalışmada bir azaltıcı (step-down) konvertörde kullanılan güç anahtarının darbeleme kayıpları devreye eklenen rezonans bank sayesinde azaltılmıştır. Rezonans devrenin özelliği dolayısıyla anahtardan geçen akımın belirli zamanlarda sıfır olması sağlanmıştır. Akımın sıfır olduğu zaman aralıklarında anahtarın pozisyonu iletimden kesime veya kesimden iletime darbeleme sinyalleri yardımıyla değiştirilmiştir. Bu darbeleme olayının sıfır akımda yapılmış olmasıyla anahtarlama kayıpları da sıfıra indirilmiştir. Anahtar Kelimeler: Sıfır akım anahtarlama, Konvertörler, Yarı iletken anahtarlarIV ABSTRACT ZERO CURRENT SWITCHING RESONANT SWITCH CONVERTERS YÜCEL Ibrahim Niğde University Graduate School of Natural Applied Science Department of Electric-Electronic Superviser: Yrd. Doç. Dr. Mustafa ALKAN September 1997, 76 pages There are two types of power losses, conducting and switching, in semiconductor devices used as a switch. The conducting losses are related with the structure of device. Therefore, it is not possible to reduce these losses after the production of the device. But, the switching losses depend on current, voltage and switching frequency of device. So, when one of these parameters is made zero, then the switching losses will be reduced to zero. İn this study, the switching losses of the switch used in a step-down converter is reduced to zero by using resonant circuit. To do this the current following in the power device is reduced to zero for a short time periodically, When the current is zero, the switch is turned on and off by switching signals. As a result of this process, the switching losses of the power device are reduced to zero. Key Words: Zero Current Switching, Convertors, Semiconductor switche
Transducer performance tests
Full text linkFen Bilimleri Enstitüsü, Elektrik-Elektronik Eğitimi Ana Bilim DalıDönüştürücüler genellikle kontrol ve ölçme sistemlerinde hissetme cihazları olarak kullanılan endüstriyel bir cihazdır. Günümüzde dönüştürücüler kullanılmadan kontrol ve ölçme alanında araştırma yapmak ve ilerleme kaydetmek mümkün değildir. Dönüştürücülerin tasarımlan kolay, fakat yapım ve kalibrasyonları zordur. Bu tez çalışması, 6 bölümden oluşmaktadır. Bölüm 1' de dönüştürücü teknolojisindeki gelişmeler ve dönüştürücülerin elektronik sistemlerindeki önemi üzerinde duruldu. Bölüm 2" de enstrümantasyon sistemleri ve buna bağlı olarak da ölçme ve kontrol sistemleri kısaca izah edildi. Dönüştürücü esasları Bölüm 3' de açıklandı. Yine bu bölümde dönüşüm prensiplerinin kullanımı üzerinde duruldu ve bunlarla ilgili tanımlamalar yapıldı. Ayrıca herhangi bir katalogdan dönüştürücü seçerken faydalı olacak çeşitli dönüştürücü karakteristikleri ayrıntılı bir şekilde verildi. Bölüm 4' te, dönüştürücü seçim kriterleri tartışıldı. Bölüm 5' te, birçok dönüştürücü karakteristikleri için dönüştürücü performans testleri denendi. Bölüm 6' da dönüştürücü karakteristikleri için hangi testlerin ve ölçmelerin daha uygun olacağı tartışıldı. Anahtar Söcükler: Dönüştürücü, entrümantasyon sistemi, dönüşüm prensibi, dönüştürücü karakteristikleri, dönüştürücü performans testleri.Transducers are industrial equipments that generally used as sensing devices in control and measurement systems. Today, it is impossible to research and to progress in control and measurement systems without using transducers. Designing of the transducers is simple, but their fabrication and calibration is difficult. This thesis is included six chapters. In the chapter one, developments in the transducer technology and, importance of the transducers in electronic systems are insisted on. In the chapter two, instrumentation systems and therefore, the measurement and the control systems are shortly explained. Transducer fundamentals are explained in the chapter three. In this chapter again, it is insisted on using of the transduction principles and the definitions about them are explained. In addition, various transducer characteristics as it is useful selecting a transducer from any transducer catalog are given in detail. In the chapter four, criteria of transducer selection are discussed. Transducer performance tests are experienced for lots of transducer characterictics in the chapter five. In the chapter six, what tests and measurements can be applied for transducer characteristics are discussed. Key Words: Transducer, instrumentation system, transduction principle, transducer characteristics, transducer performance test
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