130,575 research outputs found
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Elektrikli araçların düşük ve orta frekanslarda hava kaynaklı kompresör gürültüsünü azaltmak için yeni bir metagözenekli yapı tasarımı geliştirilmesi.
No full textMetamaterials have gained an increasing attention as a way of absorbing noise to achieve improved acoustic performance on vehicles, and thanks to their novel functionalities com pared to traditional designs, these structures are employed by many automotive companies as noise-reduction solutions for engineering applications. One of the key challenges for automotive original equipment manufacturers (OEMs) in the noise, vibration, and harsh ness (NVH) development process is absorption performance in the frequency range of 400 Hz to 800 Hz. Although sound engineers use porous polyurethane in these frequency ranges, the absorption performance of these designs is limited to meet increasing customer expectations. Besides, managing airborne noise in vehicles is particularly challenging in the low frequency spectrum. The main purpose of this study is to develop a metaporous sound barrier incorporating a Helmholtz resonator, effective in the low to mid-frequency range of the spectrum. For this purpose, a frequency domain simulation was carried out to obtain the absorption coefficient, analyze frequency-dependent effects, and identify critical frequencies in vehicle acoustics. Furthermore, local resonance effects to prevent acoustic waves were investigated and design parameters of metastructure were analyzed using a multiphysics-based simulation model. These results were validated experimen tally using an acoustic impedance tube. The methodology is demonstrated in a battery electric vehicle (BEV) to improve airborne compressor noise during motor idling. The optimum design parameters were determined using the Taguchi design method. Finally, the performance of developed metaporous material was validated through vehicle-level tests, with results showing an improvement of 3 dB(A).Metamalzemeler, arac¸larda gelis¸mis¸ akustik performansı elde etmek ic¸in gur¨ ult ¨ uy¨ u ab- ¨ sorbe etmenin yolundan biri olarak literaturde daha fazla kabul g ¨ or¨ uyor ve geleneksel ¨ tasarımlara gore yapıların yeni fonksiyonları ¨ on plana c¸ıkıyor. Birc¸ok otomotiv firması ¨ tarafından muhendislik uygulamalarında g ¨ ur¨ ult ¨ u azaltma c¸ ¨ oz¨ um¨ u olarak kullanılmaktadır. ¨ Gur¨ ult ¨ u, titres¸im ve sertlik (NVH) gelis¸tirme s ¨ urecinde otomotiv orjinal ekipman ¨ uretici- ¨ lerinin (OEM’ler) kars¸ılas¸tıgı temel zorluklardan biri 400 ile 800 Hz arasındaki g ˘ ur¨ ult ¨ uy¨ u¨ absorbe etme performansının zor olmasıdır. Ses muhendisleri bu frekans aralıklarında ¨ gozenekli poli ¨ uretan malzemeler kullansalar da bu tasarımların absorbe etme performansı ¨ artan mus¸teri beklentilerini kars¸ılamada yetersiz kalmaktadır. Ayrıca Helmholtz rezonat ¨ or- ¨ lerinin yaygın olarak kullanıldıgı d ˘ us¸¨ uk frekans spektrumunda arac¸larda hava kaynaklı ¨ gur¨ ult ¨ uy¨ u y ¨ onetmek ve engellemek oldukc¸a zordur. Bu c¸alıs¸manın esas amacı spektru- ¨ mun dus¸¨ uk-orta frekans aralı ¨ gında etkin olan Helmholtz rezonat ˘ or¨ un kullanıldı ¨ gı meta ˘ gozenekli kompozit bir ses bariyeri gelis¸tirmektir. Bu amac¸la akustik dalgaları ¨ onlemeye ¨ yonelik lokal rezonans etkileri aras¸tırılmıs¸ ve Multifizik tabanlı bir sim ¨ ulasyon modeli ¨ kullanılarak metayapının tasarım parametreleri olus¸turulmus¸tur. Metodoloji, elektrikli bir aracın (BEV) motor rolanti manevrası sırasında havadan yayılan kompres ¨ or g ¨ ur¨ ult ¨ us¨ un¨ un¨ analizi yoluyla gosterilmis¸tir. Gelis¸tirilen tasarımda optimum tasarım parametreleri Taguc- ¨ hi tasarım yontemi kullanılarak belirlenmis¸tir. Sonlu eleman modellerinin sonuc¸ları empe- ¨ dans tup¨ u¨ olc¸ ¨ umleriyle do ¨ grulanmıs¸tır. Son olarak, gelis¸tirilen meta g ˘ ozenekli malze- ¨ menin performansı arac¸ seviyesi testlerinde gerc¸ekles¸tirildi ve sonuc¸lar motor rolantide ¨ halindeyken yaklas¸ık 3 dB(A) iyiles¸me gostermis¸tir
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Scholarly Communication and Publishing Lunch and Learn Talk #11: The ULS Open Access Author Fee Fund
No full textAt the May 2014 talk, you will learn about the ULS Open Access Author Fee Fund--what it is, why we do it, how it works, and how the program is going so far
The R&D Tax Incentives
No full textThis article sets out some background information and reflections of the author on the R&D tax incentive schemes included in the Common Corporate Tax Base (CCTB) Proposal. In particular the author analyzes the stimulus to private R&D through ad hoc tax incentives included in the CCTB Proposal and dives into the actual provisions included in the Proposal highlighting the most relevant issues connected with their design and interpretation. Moreover, the author explores the interaction between the CCTB Proposal and the granting by Member States of domestic R&D tax incentives
Morphologic and functional correlates of synaptic pathology in the cathepsin D knockout mouse model of congenital neuronal ceroid lipofuscinosis
No full textMutations in the cathepsin D (CTSD) gene cause an aggressive neurodegenerative disease (congenital neuronal ceroid lipofuscinosis) that leads to early death. Recent evidence suggests that presynaptic abnormalities play a major role in the pathogenesis of CTSD deficiencies. To identify the early events that lead to synaptic alterations, we investigated synaptic ultrastructure and function in presymptomatic CTSD knockout (Ctsd) mice. Electron microscopy revealed that there were significantly greater numbers of readily releasable synaptic vesicles present in Ctsd mice than in wild-type control mice as early as postnatal day 16. The size of this synaptic vesicle pool continued to increase with disease progression in the hippocampus and thalamus of the Ctsd mice. Electrophysiology revealed a markedly decreased frequency of miniature excitatory postsynaptic currents (mEPSCs) with no effect on paired-pulse modulation of the evoked excitatory post synaptic potentials in the hippocampus of Ctsd mice. The reduced mEPSCs frequency was observed before the appearance of epilepsy or any morphologic sign of synaptic degeneration. Taken together, these data indicate that CTSD is required for normal synaptic function and that a failure in synaptic trafficking or recycling may bean early and important pathologic mechanism in Ctsd mice; these presynaptic abnormalities may initiate synaptic degeneration in advance of subsequent neuronal loss
- …
