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61.
Luca Cavanini Gionata Cimini Gianluca Ippoliti 《Journal of The Franklin Institute》2019,356(4):2015-2030
Current Mode Control (CMC) is the standard approach to regulate DC-DC power converters in high performance applications, allowing to obtain a faster time-response and better closed-loop stability if compared to Voltage Mode Control (VMC). In the last decade, several algorithms have been proposed to improve standard CMC, most of them requiring to replace the original controller. However, it is common to have either analog or embedded CMC controllers which cannot be replaced easily in commercial power converters. Inspired by very recent results in the topic, this paper proposes a Model Predictive Control (MPC) external loop aimed at optimally modifying the set-point of a CMC loop to improve converter performance. The proposed configuration is directly applicable to any pre-compensated converter as it does not require changes on the already-in-place controller. Moreover, by leveraging a multi-rate implementation, the benefits of MPC are introduced in power conversion without affecting much the computational cost of the over-all control system, contrary to what would happen for a direct MPC implementation. Simulation and experimental results on a synchronous DC-DC buck converter, controlled by a standard CMC algorithm, confirm the benefits of the approach. 相似文献
62.
Gabriel Lima-Oliveira Giuseppe Lippi Gian Luca Salvagno Martina Montagnana Geraldo Picheth Gian Cesare Guidi 《Indian journal of clinical biochemistry : IJCB》2013,28(3):235-241
A new device called Buzzy® has been recently presented that combines a cooling ice pack and a vibrating motor in order to relieve the venipuncture pain. The aim of this study was to evaluate the impact of Buzzy® use during diagnostic blood specimen collection by venipuncture for routine immunochemistry tests. Blood was collected from 100 volunteers by a single, expert phlebotomist. A vein was located on the left forearm without applying tourniquet, in order to prevent any interference from venous stasis, and blood samples were collected using a 20-G straight needle directly into 5 mL vacuum tubes with clot activator and gel separator. In sequence, external cold and vibration by Buzzy® was applied on the right forearm—5 cm above the chosen puncture site—for 1 min before venipuncture and continued until the end of the same procedure already done in the left forearm. The panel of tests included the following: glucose, total cholesterol, HDL-cholesterol, triglycerides, total protein, albumin, c-reactive protein, urea, creatinine, uric acid, alkaline phosphatase, amylase, AST, ALT, g-glutamyltransferase, lactate dehydrogenase, creatine kinase, total bilirubin, phosphorus, calcium, magnesium, iron, sodium, potassium, chloride, lipase, cortisol, insulin, thyroid-stimulating hormone, total triiodothyronine, free triiodothyronine, total thyroxine, free thyroxine and haemolysis index. Clinically significant differences between samples were found only for: total protein, albumin and transferrin. The Buzzy® can be used during diagnostic blood specimens collection by venipuncture for the majority of the routine immunochemistry tests. We only suggest avoiding this device during blood collection when protein, albumin and transferrin determinations should be performed. 相似文献
63.
Despina Paizi Maria De Luca Pierluigi Zoccolotti Cristina Burani 《Journal of Research in Reading》2013,36(3):303-329
Italian developmental dyslexic readers show a striking length effect and have been hypothesised to rely mostly on nonlexical reading. Our experiments tested this hypothesis by assessing whether or not the deficit underlying dyslexia is specific to lexical reading. The effects of lexicality, word frequency and length were investigated in the same group of children in four separate experiments. Although dyslexics were slower and less accurate than skilled readers and had large length effects, they showed lexicality and word frequency effects in both reading aloud and lexical decision. In a cross‐experiment comparison, we show that a single global factor explains a large proportion of the difference in reading performance between dyslexic and skilled readers. This factor may indicate a deficit at a prelexical level of analysis. Lexical activation seemed spared in the dyslexic children based on the effects of lexicality and frequency. These findings contrast the hypothesis that Italian dyslexics primarily engage in nonlexical reading. 相似文献
64.
Marcello De Rosa Luca Bartoli Giuseppe La Rocca 《The Journal of Agricultural Education and Extension》2013,19(5):513-535
AbstractPurpose: The aim of the paper is to analyse the attitude of Italian farms in gaining access to agricultural extension services (AES).Design/methodology/approach: The ways Italian farms use AES are described through the AKAP (Awareness, Knowledge, Adoption, Product) sequence. This article investigated the AKAP sequence by submitting a questionnaire to a sample of Italian farms, providing questions on each step of the sequence.Findings: The results confirm the validity of the model and the necessity to evaluate AES in each phase of the sequence, through an in-depth analysis of the possible motivation for not adopting them.Practical implications: The functional repositioning of agriculture redefines the role of the farm, by introducing new possibilities of production and by fostering multifunctional activities. In this context, new tasks for AES emerge, aiming at sustaining farm development along either sectorial or territorial paths. Difficulties in adopting AES call for both fostering higher levels of access to services on behalf of farms and the adequate supply of services to farms' new needs.Originality/value: AKAP models have been prevailingly used in developing countries to evaluate the efficacy of extension in increasing agricultural productivity. This article demonstrates how this model could be of help in developed agriculture too in performing new lines of development rooted in the new models of multifunctional agriculture. 相似文献
65.
Lima-Oliveira G Lippi G Salvagno GL Montagnana M Picheth G Guidi GC 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2012,22(2):180-186
Introduction
The validation process is essential in accredited clinical laboratories. Aim of this study was to validate five kinds of serum vacuum tubes for routine clinical chemistry laboratory testing.Materials and methods:
Blood specimens from 100 volunteers in five diff erent serum vacuum tubes (Tube I: VACUETTE®, Tube II: LABOR IMPORT®, Tube III: S-Monovette®, Tube IV: SST® and Tube V: SST II®) were collected by a single, expert phlebotomist. The routine clinical chemistry tests were analyzed on cobas® 6000Results and conclusions:
Basically, our validation will permit the laboratory or hospital managers to select the brand’s vacuum tubes validated according him/her technical or economical reasons, in order to perform the following laboratory tests: glucose, total cholesterol, high density lipoprotein-cholesterol, triglycerides, total protein, albumin, blood urea nitrogen, uric acid, alkaline phosphatise, aspartate aminotransferase, gamma-glutamyltransferase, lactate dehydrogenase, creatine kinase, total bilirubin, direct bilirubin, calcium, iron, sodium and potassium. On the contrary special attention will be required if the laboratory already performs creatinine, amylase, phosphate and magnesium determinations and the quality laboratory manager intend to change the serum tubes. We suggest that laboratory management should both standardize the procedures and frequently evaluate the quality of in vitro diagnostic devices. 相似文献66.
The relationship between junior boys' tennis success, as measured by a top 20 International Tennis Federation's Junior Circuit (ITFJC) ranking, and subsequent ranking accomplishments in professional men's tennis is discussed. The names, countries, and birthdates of all players to achieve a top 20 ITFJC boys' year-end ranking from 1992 to 1998 were recorded. The progress of these players through the professional ranks was then tracked to the end of 2004. Results indicate that 91% of top 20-ranked boys achieved a professional men's ranking, while a stepwise regression analysis revealed junior ranking (JR) to be a predictor of future, professional ranking (beta = 0.232, r(2) = 0.054, p < 0.05). A regression equation [predicted professional rank = 78.17 + 6.31*(JR)] accounted for a significant amount of variance in professional ranking. For male players, therefore, the achievement of a top 20 junior ranking appears to be a reasonable yardstick for future, professional success. The type of surface upon which junior players develop their games was also shown to influence professional ranking highs, with play on clay courts or a combination of clay and hard courts helping to produce higher, professionally ranked players than hard court play alone (p< or = 0.01). 相似文献
67.
Luca Soldaini Andrew Yates Elad Yom-Tov Ophir Frieder Nazli Goharian 《Information Retrieval》2016,19(1-2):149-173
The majority of Internet users search for medical information online; however, many do not have an adequate medical vocabulary. Users might have difficulties finding the most authoritative and useful information because they are unfamiliar with the appropriate medical expressions describing their condition; consequently, they are unable to adequately satisfy their information need. We investigate the utility of bridging the gap between layperson and expert vocabularies; our approach adds the most appropriate expert expression to queries submitted by users, a task we call query clarification. We evaluated the impact of query clarification. Using three different synonym mappings and conducting two task-based retrieval studies, users were asked to answer medically-related questions using interleaved results from a major search engine. Our results show that the proposed system was preferred by users and helped them answer medical concerns correctly more often, with up to a 7 % increase in correct answers over an unmodified query. Finally, we introduce a supervised classifier to select the most appropriate synonym mapping for each query, which further increased the fraction of correct answers (12 %). 相似文献
68.
This study defines the academic library as an innovation intermediary that under the service-dominant logic perspective has a role of co-creator of value instead of a traditional service provider focused on collecting and exchanging knowledge. Innovation intermediaries develop a number of roles and functions to stimulate knowledge creation and transfer by supporting interactions and collaborations among multiple parties. As result, 2×2 Matrix was created to position each library's service based on its unique combination of necessary innovation roles and functions. A single case study focused on a university library and highlighted the existence of two different types of intermediaries: generalist and specialist. 相似文献
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70.
In this paper, we analyze empirically the relation between the growth of new technology-based firms and the human capital of founders, with the aim of teasing out the “wealth” and “capability” effects of human capital. For this purpose, we take advantage of a new data set relating to a sample composed of 506 Italian young firms that operate in high-tech industries in both manufacturing and services. In accordance with competence-based theories, the econometric estimates show that the nature of the education and of the prior work experience of founders exerts a key influence on growth. In fact, founders’ years of university education in economic and managerial fields and to a lesser extent in scientific and technical fields positively affect growth while education in other fields does not. Similarly prior work experience in the same industry of the new firm is positively associated with growth while prior work experience in other industries is not. Furthermore, it is the technical work experience of founders as opposed to their commercial work experience that determines growth. The fact that within the founding team there are individuals with prior entrepreneurial experiences also results in superior growth. Lastly, we provide evidence that there are synergistic gains from the combination of the complementary capabilities of founders relating to (i) economic-managerial and scientific-technical education and (ii) technical and commercial industry-specific work experiences. We conclude that the human capital of founders of new technology-based firms is not just a proxy for personal wealth. 相似文献