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ABSTRACTHistorical pedal harps from the early nineteenth century are highly adorned objects, decorated with various techniques such as polychromy, gilding, decoupage, and gilt composition ornaments. Even though a large number of such instruments are kept in private and public collections, until now their decorative features have not been examined systematically. Moreover, little has been written about the motives behind the choice of various decorative techniques by harp makers. This article presents results from the investigation of a double-action harp made in 1818 by Erard, the leading manufacturer of harps in Regency London, focusing on the technological aspects of its decorative features. Various analytical methods, such as visual examination, microscopy, SEM-EDX, FTIR, and Py-GC-MS, were used to identify the inorganic and organic components in the coating of the harp and to analyse its stratigraphy. Inspection with ultraviolet light revealed details of the original layers and of later additions, while radiography made the internal structure as well as damaged areas and repairs visible. The outcome of this object-based examination was complemented by archival research on the Erard firm, providing new insight into Erard’s production and marketing strategies. 相似文献
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Pierros Thomakos Nikolaos Geladas Ifigenia Giannopoulou George Varouhakis Panagiotis Behrakis 《Journal of sports sciences》2020,38(5):576-581
ABSTRACTThe purpose of this study was to explore the respiratory response of acute interval and continuous exercise (CE) of low and high intensity. Fourteen recreational athletes (7 men and 7 women; VO2max = 35.7 ± 6.1 mlkg–1min–1) performed a bout of continuous and a bout of interval exercise (IE) both consisted of 5-min cycling at low intensity [80% of the power output (W) of the predetermined gas exchange threshold (GET) (80%WGET)] and 5-min cycling at high intensity {WGET plus the work rate corresponding to 50% of the difference between peak power output (PPO) at oxygen uptake (VO2max) test and the WGET [WGET + 0.50 Δ(PPO – WGET)]}. CE compared to IE induced significant higher heart rate and ventilation as well as significant higher levels of mouth occlusion pressure for 0.1 s (P0.1) (P < 0.05) during low and high intensities. Our results indicate that CE stimulates respiration more than IE when the exercise is performed at the same relative intensity. 相似文献
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Vassilios Gourgoulis Alexia Boli Nikolaos Aggeloussis Panagiotis Antoniou Argyris Toubekis Georgios Mavromatis 《Journal of sports sciences》2015,33(7):696-712
The aim of this study was to assess the effect of the hand’s acceleration on the propulsive forces and the relative contribution of the drag and lift on their resultant force in the separate phases of the front crawl underwater arm stroke. Ten female swimmers swam one trial of all-out 25-m front crawl. The underwater motion of each swimmer’s right hand was recorded using four camcorders and four periscope systems. Anatomical landmarks were digitised, and the propulsive forces generated by the swimmer’s hand were estimated from the kinematic data in conjunction with hydrodynamic coefficients. When the hand’s acceleration was taken into account, the magnitude of the propulsive forces was greater, with the exception of the mean drag force during the final part of the underwater arm stroke. The mean drag force was greater than the mean lift force in the middle part, while the mean lift force was greater than the mean drag force in the final part of the underwater arm stroke. Thus, swimmers should accelerate their hands from the beginning of their backward motion, press the water with large pitch angles during the middle part and sweep with small pitch angles during the final part of their underwater arm stroke. 相似文献
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Nita Lewis Miller Lawrence G. Shattuck Panagiotis Matsangas Jeff Dyche 《Mind, Brain, and Education》2008,2(1):29-33
ABSTRACT— This review examines the effects of military training regimes, which might include some degree of sleep deprivation, on sleep–wake schedules. We report a 4-year longitudinal study of sleep patterns of cadets at the United States Military Academy and the consequences of an extension of sleep from 6 to 8 hr per night at the United States Navy's Recruit Training Command. These studies provide an opportunity to observe sleep in a college-age population and also to record sleep patterns over an entire 4-year college experience, adding to our understanding of the changes in sleep patterns over the life span. 相似文献
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Panagiotis Symeonidis Alexandros Nanopoulos Apostolos N. Papadopoulos Yannis Manolopoulos 《Information Retrieval》2008,11(1):51-75
Collaborative Filtering (CF) Systems have been studied extensively for more than a decade to confront the “information overload”
problem. Nearest-neighbor CF is based either on similarities between users or between items, to form a neighborhood of users
or items, respectively. Recent research has tried to combine the two aforementioned approaches to improve effectiveness. Traditional
clustering approaches (k-means or hierarchical clustering) has been also used to speed up the recommendation process. In this paper, we use biclustering
to disclose this duality between users and items, by grouping them in both dimensions simultaneously. We propose a novel nearest-biclusters
algorithm, which uses a new similarity measure that achieves partial matching of users’ preferences. We apply nearest-biclusters
in combination with two different types of biclustering algorithms—Bimax and xMotif—for constant and coherent biclustering,
respectively. Extensive performance evaluation results in three real-life data sets are provided, which show that the proposed
method improves substantially the performance of the CF process.
相似文献
| Yannis ManolopoulosEmail: |
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Panagiotis Pappas Charilaos Tsolakis Athanasia Smirniotou Jean-Benoit Morin 《Sports biomechanics / International Society of Biomechanics in Sports》2014,13(4):391-399
The aim of this study was to determine the intra-participant variabilities (i.e. intra-day and inter-day reliabilities) in leg and vertical stiffness, as well as related kinematic parameters, during treadmill running using the sine-wave method. Twenty-two healthy men ran on a treadmill at 4.44 m/s, and the flight and contact times were measured with a high-speed video camera. Three 30-s running bouts with 2-min inter-bout rests were performed to examine the intra-day reliability, and single 30-s running bouts on three separate days with 24- to 48-h inter-bout intervals were performed to examine the inter-day reliability. The reliability statistics included repeated-measure analyses of variance, average inter-trial correlations, intra-class correlation coefficients (ICCs), Cronbach's α reliability coefficient, and the coefficient of variation. Both leg and vertical stiffness produced high ICCs within 0.972 and 0.982, respectively, and between 0.922 and 0.873 days, respectively. High values were also observed for all of the reliability coefficients. Similar results were found regarding contact time, flight time, step length, and step rate. It was concluded that the measurements of leg and vertical stiffness, as well as related kinematic parameters, obtained using the sine-wave method during treadmill running at 4.44 m/s, were highly reliable, both within and across days. 相似文献
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Schools play a crucial role in preparing students for a technology-driven world. Although schools incorporate technology for teaching and learning in promising ways, reviewing their organisational strategies would enhance their digital capacity—namely, the effective integration of technology in teaching and learning practices. This article presents insights for improving schools' digital capacity provided by school leaders, teachers, and students from fourteen European countries, through open-ended questions on the SELFIE online tool for collective reflection. This article presents the thematic analysis conducted on 5247 excerpts collected through SELFIE questionnaires, referring to participants' perceptions of their schools' digital infrastructure, the usefulness of technology for teaching and learning, and the perceived need to make the most of technology. Findings align with international studies, which confirm that schools' digital infrastructure still needs improving, while teachers need more training on embedding technology in their teaching practices. Findings also reveal differences in school leaders, teachers, and students' viewpoints and experiences on technology use in their schools. Comparing viewpoints and experiences regarding a school's digital capacity by using a comprehensive and structured process of collective reflection, the SELFIE tool is unique within the field and can offer insights to school communities, education policymakers and researchers. 相似文献
9.
Piperakis Stylianos M. Papadimitriou Vasiliki Piperakis Michael M. Zisis Panagiotis 《Journal of Science Education and Technology》2003,12(2):135-141
The purpose of this study was to assess Greek primary (1st to 6th grade) school children's understanding of sun exposure during summer vacation. Our results show that children know the damaging effects of long time exposure and the precautions that should be taken during sun bathing (sun glasses, hat, umbrella, sunscreen, etc). Nevertheless, they do not seem to avoid being exposed between 12.00 A.M. and 15.00 P.M., which is the most dangerous time. The socioeconomic status of father has no effect on the attitude of children towards taking protection measures when exposed to the sun, however, the educational status of the mother appears to influence children's reported knowledge and behaviour. Place of residence (urban or rural areas) and gender does not influence their knowledge on the sun's damaging effects and the precautions they should take. Finally, as children grow older they seem to gradually reduce the protective measures they take. 相似文献
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Our research is focused on the selection, classification and comparative presentation of the various proposals concerning the contribution of the history of physics in physics education, that have been designed and/or carried out as part of either research or curriculum development during the last century. The framework of the classification is the result of the study of the aims of the teaching-learning of physics, as they have been presented since the 1960s, coupled with the current trends in science education, including discovery learning in the 1960s and constructivism nowadays. The study of the various proposals concerning the contribution of the history of physics in physics education revealed different points of view and led to the creation of new sub-categories of the initial framework. In an attempt to havea better overall view of the classification, we designed a chart so that the various proposals reported could be observed and commented on in a comparative way. The framework of the classification is presented on the vertical axis of a chart, while time from 1893, the year of the earliest referenceavailable (Lodge 1893), till today is presented on the horizontal axis. 相似文献