scholarly journals Lumped-Parameters Thermal Network of PM Synchronous Machines for Automotive Brake-by-Wire Systems

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5652
Author(s):  
Federica Graffeo ◽  
Silvio Vaschetto ◽  
Alessio Miotto ◽  
Fabio Carbone ◽  
Alberto Tenconi ◽  
...  

Thermal analysis represents a key factor in electrical machine design due to the impact of temperature increase on insulation lifetime. In this context, there has been a wide investigation on thermal modeling, particularly for machines used in harsh working conditions. In this perspective, brake-by-wire (BBW) systems represent one of the most challenging applications for electrical machines used for automotive smart actuators. Indeed, electro-actuated braking systems are required to repeatedly operate the electric machine in high overload conditions in order to limit the actuator response time, as well as to enhance gravimetric and volumetric specific performance indexes. Moreover, BBW systems often impose unconventional supply conditions to the electric machine, consisting of dc currents in three-phase windings to keep the rotor fixed during the braking intervals. However, a dc supply leads to uneven temperature distributions in the machine, and simplified thermal models may not accurately represent the temperature variations for the different machine parts. Considering such unconventional supply conditions, this paper initially investigates the applicability of a conventional lumped-parameters thermal network (LPTN) based on symmetry assumptions for the heat paths and suitable for surface-mounted PM synchronous machines used in BBW systems. An extensive test campaign consisting of pulses and load cycle tests representative of the real machine operations was conducted on a prototype equipped with several temperature sensors. The comparison between measurements and predicted average temperatures, together with insights on the unbalanced heat distribution under the dc supply obtained by means of finite element analyses (FEA), paved the way for the proposal of a phase-split LPTN with optimized parameters. The paper also includes a critical analysis of the optimized parameters, proposing a simplified, phase-split lumped-parameters thermal model suitable to predict the temperature variations in the different machine parts for PM synchronous electric machines used in BBW systems.

2009 ◽  
pp. 54-69 ◽  
Author(s):  
A. Shastitko ◽  
S. Avdasheva ◽  
S. Golovanova

The analysis of competition policy under economic crisis is motivated by the fact that competition is a key factor for the level of productivity. The latter, in its turn, influences the scope and length of economic recession. In many Russian markets buyers' gains decline because of the weakness of competition, since suppliers are reluctant to cut prices in spite of the decreasing demand. Data on prices in Russia and abroad in the second half of 2008 show asymmetric price rigidity. At least two questions are important under economic crisis: the 'division of labor' between pro-active and protective tools of competition policy and the impact of anti-crisis policy on competition. Protective competition policy is insufficient in transition economy, especially in the days of crisis it should be supplemented with the well-designed industrial policy measures which do not contradict the goals of competition. The preferable tools of anti-crisis policy are also those that do not restrain competition.


Author(s):  
Rodrigo Cueva ◽  
Guillem Rufian ◽  
Maria Gabriela Valdes

The use of Customer Relationship Managers to foster customers loyalty has become one of the most common business strategies in the past years.  However, CRM solutions do not fill the abundance of happily ever-after relationships that business needs, and each client’s perception is different in the buying process.  Therefore, the experience must be precise, in order to extend the loyalty period of a customer as much as possible. One of the economic sectors in which CRM’s have improved this experience is retailing, where the personalized attention to the customer is a key factor.  However, brick and mortar experiences are not enough to be aware in how environmental changes could affect the industry trends in the long term.  A base unified theoretical framework must be taken into consideration, in order to develop an adaptable model for constructing or implementing CRMs into companies. Thanks to this approximation, the information is complemented, and the outcome will increment the quality in any Marketing/Sales initiative. The goal of this article is to explore the different factors grouped by three main domains within the impact of service quality, from a consumer’s perspective, in both on-line and off-line retailing sector.  Secondly, we plan to go a step further and extract base guidelines about previous analysis for designing CRM’s solutions focused on the loyalty of the customers for a specific retailing sector and its product: Sports Running Shoes.


2018 ◽  
Author(s):  
Dave L Dixon ◽  
William L Baker

BACKGROUND The impact and quality of a faculty members publications is a key factor in promotion and tenure decisions and career advancement. Traditional measures, including citation counts and journal impact factor, have notable limitations. Since 2010, alternative metrics have been proposed as another means of assessing the impact and quality of scholarly work. The Altmetric Attention Score is an objective score frequently used to determine the immediate reach of a published work across the web, including news outlets, blogs, social media, and more. Several studies evaluating the correlation between the Altmetric Attention Score and number of citations have found mixed results and may be discipline-specific. OBJECTIVE To determine the correlation between higher Altmetric Attention Scores and citation count for journal articles published in major pharmacy journals. METHODS This cross-sectional study evaluated articles from major pharmacy journals ranked in the top 10% according to the Altmetric Attention Score. Sources of attention that determined the Altmetric Attention Score were obtained, as well each articles open access status, article type, study design, and topic. Correlation between journal characteristics, including the Altmetric Attention Score and number of citations, was assessed using the Spearman’s correlation test. A Kruskal-Wallis 1-way analysis of variance (ANOVA) was used to compare the Altmetric Attention Scores between journals. RESULTS Six major pharmacy journals were identified. A total of 1,376 articles were published in 2017 and 137 of these represented the top 10% with the highest Altmetric Attention Scores. The median Altmetric Attention Score was 19 (IQR 15-28). Twitter and Mendeley were the most common sources of attention. Over half (56.2%) of the articles were original investigations and 49.8% were either cross-sectional, qualitative, or cohort studies. No significant correlation was found between the Altmetric Attention Score and citation count (rs=0.07, P = 0.485). Mendeley was the only attention source that correlated with the number of citations (rs=0.486, P<0.001). The median Altmetric Attention Score varied widely between each journal (P<0.001). CONCLUSIONS The overall median Altmetric Attention score of 19 suggests articles published in major pharmacy journals are near the top 5% of all scientific output. However, we found no correlation between the Altmetric Attention Score and number of citations for articles published in major pharmacy journals in the year 2017.


2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
A. Andronic ◽  
J. Honermann ◽  
M. Klasen ◽  
C. Klein-Bösing ◽  
J. Salomon

Abstract In this paper we present a study of in-medium jet modifications performed with JEWEL and PYTHIA 6.4, focusing on the uncertainties related to variations of the perturbative scales and nuclear parton distribution functions (PDFs) and on the impact of the initial and crossover temperature variations of the medium. The simulations are compared to LHC data for the jet spectrum and the nuclear modification factor. We assess the interplay between the choice of nuclear PDFs and different medium parameters and study the impact of nuclear PDFs and the medium on the jet structure via the Lund plane.


Author(s):  
Ioulia Kokka ◽  
Iraklis Mourikis ◽  
Nicolas C. Nicolaides ◽  
Christina Darviri ◽  
George P. Chrousos ◽  
...  

Adolescent suse internet via several devices to gather information or communicate. Sleep, as a key factor of adolescents’ development, contributes to their physical and mental health. Over the past decades insufficient sleep among adolescents has been wide spread, and one of its attributing factors is the increased availability of technology. This review aims to investigate the body of evidence regarding the impact of problematic internet use on adolescent sleep. Extensive search of databases was performed according to PRISMA guidelines for studies published within the last decade, regarding subjects aged 10–19. The final step of the search yielded 12 original studies. The quality of extracted data was evaluated with the AXIS tool, in order to estimate the risk of bias. All studies showed a negative correlation between adolescent sleep and problematic internet use. It was found to affect sleep quality and quantity and provoke insomnia symptoms. Interestingly, adolescent’s sex, parental educational level, type of family and use for leisure or academic reasons appeared as affecting factors of the problematic internet use-sleep relationship. Problematic internet use has several effects on adolescents’ sleep. Results of relevant studies should be embedded in educational interventions addressed to adolescents as well as parents, to eliminate the negative outcomes of problematic internet use on sleep and adolescence’s health in general.


2018 ◽  
Vol 89 (5) ◽  
pp. 881-890 ◽  
Author(s):  
Su Liu ◽  
Yanping Liu ◽  
Li Li

Conductive yarn is the key factor in fabricating electronic textiles. Generally, three basic fabric production methods (knit, woven, and non-woven) combined with two finishing processes (embroidery and print) are adopted to embed conductive yarns into fabrics to achieve flexible electronic textiles. Conductive yarns with knit structure are the most flexible and effective form of electronic textiles. Electronic textiles present many advantages over conventional electronics. However, in the process of commercialization of conductive knitted fabrics, it is a great challenge to control the complicated resistive networks in conductive knitted fabrics for the purpose of cost saving and good esthetics. The resistive networks in conductive knitted fabrics contain length-related resistance and contact resistance. The physical forms of conductive yarns in different fabrication structures can be very different and, thus, the contact resistance varies greatly in different fabrics. So far, study of controlling the resistive property of conductive fabrics has not been conducted. Therefore, establishing a systematic method for the industry as a reference source to produce wearable electronics is in great demand. During the industrialization of conductive knitted fabrics, engineers can estimate the resistive property of the fabric in advance, which makes the production process more effective and cost efficient. What is more, the resistive distribution in the same area of knitted fabrics can be fully controlled.


2012 ◽  
Vol 9 (3) ◽  
pp. 1033-1040 ◽  
Author(s):  
M. Barlett ◽  
K. Zhuang ◽  
R. Mahadevan ◽  
D. Lovley

Abstract. Enhancing microbial U(VI) reduction with the addition of organic electron donors is a promising strategy for immobilizing uranium in contaminated groundwaters, but has yet to be optimized because of a poor understanding of the factors controlling the growth of various microbial communities during bioremediation. In previous field trials in which acetate was added to the subsurface, there were two distinct phases: an initial phase in which acetate-oxidizing, U(VI)-reducing Geobacter predominated and U(VI) was effectively reduced and a second phase in which acetate-oxidizing sulfate reducing bacteria (SRB) predominated and U(VI) reduction was poor. The interaction of Geobacter and SRB was investigated both in sediment incubations that mimicked in situ bioremediation and with in silico metabolic modeling. In sediment incubations, Geobacter grew quickly but then declined in numbers as the microbially reducible Fe(III) was depleted whereas the SRB grow more slowly and reached dominance after 30–40 days. Modeling predicted a similar outcome. Additional modeling in which the relative initial percentages of the Geobacter and SRB were varied indicated that there was little to no competitive interaction between Geobacter and SRB when acetate was abundant. Further simulations suggested that the addition of Fe(III) would revive the Geobacter, but have little to no effect on the SRB. This result was confirmed experimentally. The results demonstrate that it is possible to predict the impact of amendments on important components of the subsurface microbial community during groundwater bioremediation. The finding that Fe(III) availability, rather than competition with SRB, is the key factor limiting the activity of Geobacter during in situ uranium bioremediation will aid in the design of improved uranium bioremediation strategies.


2017 ◽  
Vol 9 (1) ◽  
pp. 122 ◽  
Author(s):  
Alenka Fikfak ◽  
Saja Kosanović ◽  
Miha Konjar ◽  
Janez Grom ◽  
Martina Zbašnik-Senegačnik

2016 ◽  
Vol 52 (4) ◽  
pp. 2951-2960 ◽  
Author(s):  
Malgorzata Sumislawska ◽  
Konstantinos N. Gyftakis ◽  
Darren F. Kavanagh ◽  
Malcolm D. McCulloch ◽  
Keith J. Burnham ◽  
...  

2005 ◽  
Vol 31 (2) ◽  
Author(s):  
N. Ndlovu ◽  
S. Brijball Parumasur

Change is a way of life and the ability to manage change is a key factor in organisational survival and effectiveness. This article evaluates the ‘survivor syndrome’ and assesses the impact of the process of downsizing and transformation on communication, trust, survivor commitment and loyalty, morale and career advancement opportunities. The study was conducted using a stratified random sample of 361 employees/survivors in a branch of a motor manufacturer that had undergone major transformation. Data was collected using a self-developed questionnaire and analysed using descriptive and inferential statistics. The study generates a framework/model of critical change implementation factors and recommendations that will enable change managers to sense, adjust, respond and implement change timeously so as to gain strategic and competitive advantage. Opsomming Verandering is ’n lewenswyse en die vermoë om te verander is ’n kernaspek in organisasieverandering en -oorlewing. In hierdie artikel word die ‘oorlewingsindroom’ beoordeel en word die impak van die afskalingsproses en transformasie op kommunikasie, vertroue, ‘oorlewende’ toewyding en lojaliteit, moraal en loopbaanvorderingsgeleenthede takseer. Die studie is uitgevoer, met die gebruik van ’n gestratifiseerde ewekansige steekproef van 361 werknemers/’oorlewendes’ in ’n afdeling van ’n motorvervaardiger wat ingrypende transformasie ondergaan het. Data is ingesamel by wyse van ’n selfontwikkelde vraelys en ontleed aan die hand van beskrywende en inferensiële statistiek. Die studie het ’n raamwerk/model van kritieke veranderingsimplementeringsfaktore en aanbevelings gegenereer wat veranderingsbestuurders in staat sal stel om die gewaarwording, aanpassing, reaksie en implementering van verandering tydig te doen sodat strategiese en mededingingsvoordeel behaal kan word.


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