1,721,536 research outputs found
Efficient Query Processing for Dynamically Changing Datasets
Full text linkThe ability to efficiently analyze changing data is a key requirement of many real-time analytics applications. Traditional approaches to this problem were developed around the notion of Incremental View Maintenance (IVM), and are based either on the materialization of subresults (to avoid their recomputation) or on the recomputation of subresults (to avoid the space overhead of materialization). Both techniques are suboptimal: instead of materializing results and subresults, one may also maintain a data structure that supports efficient maintenance under updates and from which the full query result can quickly be enumerated. In two previous articles, we have presented algorithms for dynamically evaluating queries that are easy to implement, efficient, and can be naturally extended to evaluate queries from a wide range of application domains. In this paper, we discuss our algorithm and its complexity, explaining the main components behind its efficiency. Finally, we show experiments that compare our algorithm to a state-of-the-art (Higher-order) IVM engine, as well as to a prominent complex event recognition engine. Our approach outperforms the competitor systems by up to two orders of magnitude in processing time, and one order in memory consumption
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
Analysis of the Effect of Centrifugal Pump Suction Height on Pump Capacity and Efficiency
No full text71Pompa adalah peralatan mekanis untuk meningkatkan energi tenakan pada cairan (fluida) yang dipompa dengan mengubah energi mekanis poros penggerak menjadi energi potensial dan energi kinetis fluida. Seiring berkembangnya teknologi, pompa digunakan diberbagai bidang termasuk pemakaiannya dalam bidang indsutri. Pompa Sentrifugal merupakan salah satu jenis pompa yang mempunyai lingkup penggunaan yang sangat luas terkait dengan head dan kapasitas yang dihasilkan. Pada kesempatan ini penulis mencoba memaparkan hasil penelitian tentang unjuk kerja pompa sentrifugal bila dilakukan variasi tinggi hisap pada pompa sentrifugal akan mempengaruhi kapasitas, Head, Daya Hidraulis dan effesiensi pompa sentrifugal. Variasi tinggi hisap dimaksudkan untuk mengetahui peningkatan performance pompa yang terjadi akibat penambahan tinggi hisap pompa. Menambah tinggi hisap pompa sangat berpengaruh terhadap kapasitas aliran air yang dihasilkan, hal ini juga akan mempengaruhi kerja pompa, kecepatan spesifik, daya dan efesiensi pompa. Sehingga dapat diperoleh titik kerja tertinggi pompa sentrifugal dengan Kapasitas (Q) 0,001180 m3/s, Head (H) 6,066 m, Daya Hidraulis (Ph) 70,008 watt, Effesiensi (ɳp) 26,51 %, hal tersebut berpengaruh bila dilakukan penambahan daya dari motor penngerak pompa tersebut. The pump is a mechanical device to increase the force energy of the pumped fluid (fluid) by converting the drive shaft mechanical energy into potential energy and fluid kinetic energy. Along with the development of technology, pumps are used in various fields including their use in the industrial sector. Centrifugal pump is one type of pump that has a very wide scope of use related to the head and capacity produced. On this occasion, the author tries to explain the results of research on the performance of centrifugal pumps. When variations in suction height are carried out on a centrifugal pump, it will affect the capacity, head, hydraulic power and efficiency of the centrifugal pump. the variation in suction height is intended to determine the increase in pump performance that occurs due to the addition of the pump suction height. Increasing the suction height of the pump greatly affects the capacity of the resulting water flow, this will also affect pump work, specific speed, power and pump efficiency. So that it can be obtained the highest working point of a centrifugal pump with a capacity (Q) 0.001180 m3 / s, Head (H) 6.066 m, Hydraulic Power (Ph) 70,008 watts, Efficiency (ɳp) 26,51 %, this has an effect when adding power from the motor driving the pump
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
Analisis Unjuk Kerja Pompa Sentrifugal dengan Variasi Head
Full text linkPompa Sentrifugal merupakan salah satu jenis pompa yang mempunyai lingkup penggunaan yang sangat luas terkait dengan head dan kapasitas yang dihasilkan. Pada kesempatan ini penulis mencoba memaparkan hasil penelitian tentang unjuk kerja pompa sentrifugal bila dilakukan variasi sudut bukaan katup (valve) pada pompa sentrifugal akan menghasilkan head. Sudut bukaan katup (valve) dimaksudkan untuk mengetahui peningkatan performance pompa yang terjadi akibat pembukaan sudut katup (valve). Menambah bukaan katup (valve) pompa sangat berpengaruh terhadap kapasitas aliran air yang dihasilkan, hal ini juga akan mempengaruhi kerja pompa, kecepatan spesifik, daya dan efesiensi pompa. Sehingga dapat diperoleh titik kerja pompa sentrifugal dengan Kapasitas (Q) 0,000733 m3/s, Head (H) 7,02 m, Daya Hidraulis (Ph) 50,501 watt, Effesiensi (ɳp) 16,396%, hal ini dapat terlaksana bila diikuti penambahan daya dari motor penggeraknya.Centrifugal pump is one type of pump that has a very wide scope of use related to the head and the capacity produced. On this occasion the author tries to explain the results of research on the performance of a centrifugal pump if variations in valve opening angle (valve) on a centrifugal pump will produce a head. The valve opening angle is intended to determine the increase in pump performance due to the opening of the valve angle. Adding to the valve opening (pump) is very influential on the flow capacity of the water produced, this will also affect the work of the pump, specific speed, power and pump efficiency. So that the centrifugal pump working point can be obtained with Capacity (Q) 0,000733 m3 / s, Head (H) 7,02 m, Hydraulics (Ph) 50,501 watts, Efficiency ((p) 16,396%, this can implemented if followed by the addition of power from the driving motor
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
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