112,895 research outputs found
How much can large-scale Video-On-Demand benefit from users' cooperation?
No full textWe propose an analytical framework to tightly characterize the scaling laws for the additional bandwidth that servers must supply to guarantee perfect service in peer-assisted Video-on-Demand systems, taking into account essential aspects such as peer churn, bandwidth heterogeneity, and Zipf-like video popularity. Our results reveal that the catalog size and the content popularity distribution have a huge effect on the system performance. We show that users' cooperation can effectively reduce the servers' burden for a wide range of system parameters, confirming to be an attractive solution to limit the costs incurred by content providers as the system scales to large populations of user
Characteristics of the beams generated by a “hollow cathode” electron gun
No full textThe characteristics of a beam generated by a “hollow cathode” gun, intended for electron cooling purposes, are thoroughly investigated. Attention was focused on the details of the current density and temperature distributions across the electron beam. Consequently a high quality beam was obtained, comparable with the beams generated by standard guns. Much insight was gained on the vacuum and alignment conditions for this new configuration
author-bios-SRD-19-0063.R1 – Supplemental material for The Network Structure of Police Misconduct
No full textSupplemental material, author-bios-SRD-19-0063.R1 for The Network Structure of Police Misconduct by George Wood, Daria Roithmayr and Andrew V. Papachristos in Socius</p
Time Reversal Invariance Test at the COSY Ring
No full textTime reversal violation (T –V), like the equivalent violation of the combined symmetries of charge
(C) and parity (P) (CP–V), is a necessary ingredient for any theory aiming to address the mystery
of the matter–antimatter asymmetry of our Universe - one of the biggest problems in contemporary
physics and cosmology. It is widely accepted that a solution of this puzzle will involve new physics
Beyond the Standard Model (BSM) of elementary particle physics.
At the COoler SYnchroton (COSY) a null test (P–even, T –odd) of time reversal invariance is un-
der feasability study as an internal transmission experiment. The parity conserving time–reversal
violating observable is the spin correlation parameter AY,XZ in the double–polarized proton–deuteron
scattering, which can be accessed by using a polarized proton beam passing through an internal
tensor polarized deuterium target
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
Variations on the Author
No full text“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
The PolFusion Experiment: Measurement of the d-d-Fusion Spin-Dependence
No full textA double-polarized dd-fusion experiment is under preparation at PNPI,
Gatchina. The experimental program includes themeasurements of the asymmetry in
the differential cross section of the reactions d_pol + d_pol → 3He + n and d_pol + d_pol → t + p. The spin-correlation coefficients Cz,z and Czz,zz will be measured to determine
the quintet-state suppression factors for both reactions, for which quite different
theoretical predictions were made and which are very important for the design of
future neutron-lean fusion reactors. The total cross sectionmodification for polarized
d–d fusion will also be investigated. An increase by a factor of 1.5 was already
deduced for the d + 3He and the d + t reactions. The experimental setup and the
future upgrade plans are described
Polarization REsearch for Fusion Experiments and Reactors - The PREFER Collaboration: Purposes and Present Status
No full textThe PREFER (Polarization REsearch for Fusion Experiments and Reactors) collaboration aims to address the know–hows in different fields and techniques to the challenging bet on fusion with polarized fuel. The efforts on a variety of duties and goals are shared between different research groups, indicated here by underlining in the authors’ list the scientific responsibles. Starting from still open questions of fusion reaction physics, as for example the study of D+D spin–dependent cross–sections (Vasilyev) to the acceleration of polarized ions from laser-induced plasmas (Büscher), there are many connections between the involved research groups. The collaboration is also tackling the production of nuclear polarized molecules, recombined from a polarized atomic beam (Engels), and its cryogenic condensation and transport (Ciullo). Other options for the production of polarized fuel are investigated in parallel, like spin separation of molecules in polarized molecular beam sources (Toporkov), or via photodissociation of molecules into polarized hydrogen/deuterium atoms (Rakitzis). The status of the different fields under investigation and the connections between these topics and the different research groups will be provided
Internal gas target experiments at the LHC
No full textThe physics opportunities offered by a fixed-target program using the proton and lead-ion beams of the LHC is wide and exciting. The LHC beams can provide the most energetic fixed-target measurements by pp, pA, and PbA collisions at √sNN = 72–115 GeV probing unexplored regions of the kinematical plane, including the high-x region. In the case of an unpolarized target the physics rich ranges from QCD to astroparticle, while the polarized target option opens the ground to novel measurements of TMDs, thereby contributing with a complementary approach to the understanding of the dynamics of the quark-gluon interplay inside the nucleon up to the 3-dimensional description of the nucleons. Among the main LHC experiments LHCb is the most suitable to host a fixed gas target. A description of the ongoing fixed-target proposals aimed at having the first LHC unpolarized data in Run3 and polarized data in Run4 will be discussed
Využití sociálních médií v B2B prodeji
No full textTato diplomová práce se zabývá tím, jak mohou B2B obchodníci využívat sociální média v prodeji. Na základě systematické rešerše literatury, autor zjistil, že akademici, zkoumající danou problematiku, navrhují další výzkum, a to: v kterých konkrétních krocích se dají využít sociální média v prodeji (Salo, 2017). Autor se na základě toho rozhodl zjistit, jaké sociální sítě, různé technologie a pluginy se dají využít v B2B prodeji - tzv. social sellingu. Social selling se v této práci týká primárně procesu akvizice a okrajově péčí o stávající zákazníky. Autor si vybral kvalitativní průzkum pomocí 10 hloubkových polo-strukturovaných rozhovorů, aby odhalil jak, která sociální média to jsou, tak i motivaci prodejců, proč tato média používat/nepoužívat. Aby autor dodržel správnost vyhodnocení výsledků, data byla analyzována pomocí Tématické analýzy, která v této studii vykrystalizovala 2 hlavní strategické přístupy v social sellingu. Tyto přístupy (tzv. Push a Pull strategie) obsahují praktické příklady a konkrétní aktivity, které mohou prodejci využívat v každodenní praxi. Tyto výsledky jsou prezentovány s důrazem na praktičnost a jednoduchost implementace. Tvoří proto hlavní přínos autorovo výzkumu. V poslední části autor zmiňuje výzvy a manažerská doporučení, které mohou obchodníci využít v každodenním pracovním životě.This diploma thesis focuses on social media usage in B2B sales. Based on the systematic literature review conducted by the author, he has found out that recent researchers (Salo, 2017) suggest further research in the area of how and in which sales phase should various social networking sites, technologies and plugins used. To further fill this research gap, author decided to identify these social media and their usage among B2B salespeople in the so-called social selling process. The social selling process in this thesis applies mainly to acquiring new prospects and tangentially to taking care of existing clients (follow-up step). Author has chosen a qualitative research method via conducting 10 in-depth semi-structured interviews to reveal these instruments as well as motivation of a sales person on why to use social media in the selling process. The collected data was analyzed using Thematic analysis to ensure the right procedure and to identify main themes which crystalized into 2 main strategic approaches in social selling. These approaches (Push and Pull) include practical examples of concrete activities which sales people can use in their daily jobs and are presented with focus on practicality and ease of implementation. These also form the main contribution of author`s research. In the last part, author mentions challenges in social selling and recommended managerial implications for salesforce
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