Effect of different loading conditions on running mechanics at different velocities     

Germán Carretero-Navarro  Doménico Cherubini  Wolfgang Taube 《European Journal of Sport Science》2019,19(5):595-602

Weighted vests are widely used to improve running economy and performance. However, it is not well-studied how running mechanics are adapted to counteract the higher peak vertical ground reaction forces (Fpeak) while running with such a device. Therefore, the present study aimed to investigate the effects of different loading conditions on running mechanics at different velocities. Thirteen subjects participated in two separate sessions one week apart. In the first session, maximal aerobic speed (MAS) was determined through a maximal incremental running test while in the second session, they were instructed to run during one minute under different loading (0%, +10% and +20% of body mass [BM]) and velocity (60%, 80% and 100% of MAS) conditions in a random order. Spatiotemporal data were recorded and then running mechanics modelled using the spring-mass model. The main results indicated that vertical and leg stiffness (Kvert and Kleg, respectively) were increased (P?P?>?.05) when load was changed. At the same time, alterations of the running kinematics were observed such as longer contact times, reduced flight times, stride frequencies and step lengths, as well as an increase of the centre of mass dynamics. Based on these results it is assumed that runners maintain a certain stiffness level for each velocity despite different loading conditions. As a consequence, Fpeak increases and this probably causes spatiotemporal adjustments in the movement kinematics.  相似文献   

Photography in colors     

Wilhelm Grune 《Journal of The Franklin Institute》1870,89(2):134-136

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REAL: Ein ressourcenadaptierendes mobiles Navigationssystem     

Wolfgang Wahlster  J?rg Baus  Christian Kray und Antonio Krüger 《Informatik - Forschung und Entwicklung》2001,16(4):233-241

Zusammenfassung.   Die intelligente Ressourcenadaption ist eine der gro?en Herausforderungen für die n?chste Generation mobiler Navigationssysteme. Da man typischerweise mehrere Fortbewegungsarten oder Verkehrsmittel kombinieren muss, um an einen Zielort zu gelangen, muss sichergestellt werden, dass mobile, allgegenw?rtige Navigationshilfen dies über eine jeweils situationsangepasste Benutzerschnittstelle unterstützen. Der notwendige Wechsel zwischen verschiedenen Positionierungstechnologien soll für den Endbenutzer m?glichst unbemerkt bleiben. Im folgenden wird ein hybrides Personennavigationssystem vorgestellt, das die in bestimmten Fortbewegungssituationen verfügbaren Positionierungstechnologien und deren Genauigkeit optimal nutzt, um die Pr?sentation der Wegbeschreibung auf verschiedene Endger?te und Ausgabemodalit?ten sowie die kognitive Ressourcenlage des Benutzers zu adaptieren. Eingegangen am 28. Februar 2001 / Angenommen am 8. August 2001  相似文献   

Emergent rationality in technological policy: Nuclear energy in the Federal Republic of Germany     

Wolfgang Fach  Edgar Grande 《Minerva》1992,30(1):14-27

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Editorial     

Donsbach  Wolfgang; Noelle-Neumann  Elisabeth; Traugott  Michael W.; Worcester  Robert 《Int. Journal of Public Opinion Research》2006,18(3):273-274

This issue of the Journal contains three interesting articlesabout central aspects of public opinion research, as well asan equal number of research notes that reflect the range oftopics that interest all public opinion researchers. Toshio Takeshita takes a turn at reconceptualizing agenda-settingstudies, using a taxonomy  相似文献   

Forschungs- und Entwicklungsprojekte
Virtuelle Maschinen: zSeries- und S/390-Partitionierung     

Joachim von Buttlar  Wilhelm G. Spruth 《Informatik - Forschung und Entwicklung》2004,39(1):41-54

Der gleichzeitige Betrieb mehrerer Gast-Betriebssysteme auf einem einzigen physischen Rechner unter einem Host-Betriebssystem ist eine leistungsfähige moderne Entwicklung. Bekannte Beispiele sind VMware für die IA32-Architektur sowie das Betriebssystem z/VM und die PR/SM-LPAR Einrichtungen der zSeries-Architektur. Die Nutzung eines Betriebssystems als Gast bedingt einen Leistungsverlust. Die als Partitionierung bezeichnete Zuordnung von Systemressourcen zu den einzelnen Gast-Betriebssysteme ist schwierig, wenn eine dynamische Anpassung an sich ändernde Lastprofile erforderlich ist. Diese Probleme lassen sich mittels Erweiterungen der Hardwarearchitektur adressieren, sowie durch Softwarestrukturen, welche diese Erweiterungen nutzen. Die Erweiterungen der Hardwarearchitektur gehen über das hinaus, was auf heutigen Rechnerarchitekturen wie IA32 oder Mips verfügbar ist. Der vorliegende Beitrag erläutert den optimalen Betrieb von Gast-Betriebssystemen und die begleitenden Partitionierungsmöglichkeiten auf der zSeries-Plattform und beschreibt die zusätzlichen Hardware- und Software-Einrichtungen, welche dies ermöglichen.  相似文献   

Enhancing nursing home care for seniors: impact of a living classroom on nursing assistant’s education     

Veronique M. Boscart  Lynn McCleary  Paul Stolee  Linda Sheiban Taucar  Jessica Wilhelm  Keia Johnson 《Educational gerontology》2020,46(8):461-472

ABSTRACT

Nursing Assistants (NAs) are the largest workforce in nursing homes, but often lack adequate preparation for their role. The Living Classroom (LC) is an integrated learning approach, whereby a NA program is delivered in a nursing home (NH) in collaboration with a community college. This paper describes the implementation and evaluation of the LC. Mixed methods were used to gather data from 48 NA students, 5 faculty, and 42 NH staff over 30 weeks. Students, faculty, and nursing home staff described the LC as a positive learning experience. Students’ gerontological knowledge increased over time (p = .0012). Students reported very positive relationships with program mentors and NH residents. The LC provides a unique approach to prepare NAs to work in nursing homes. This model could expand to other educational programs with a gerontology focus.  相似文献   

Channel adaptive rate control for energy optimization     

Blanch Carolina  Pollin Sofie  Lafruit Gauthier  Eberle Wolfgang 《浙江大学学报(A卷英文版)》2006,7(1):82-88

Low energy consumption is one of the main challenges for wireless video transmission on battery limited devices. The energy invested at the lower layers of the protocol stack involved in data communication, such as link and physical layer, represent an important part of the total energy consumption. This communication energy highly depends on the channel conditions and on the transmission data rate. Traditionally, video coding is unaware of varying channel conditions. In this paper, we propose a cross-layer approach in which the rate control mechanism of the video codec becomes channel-aware and steers the instantaneous output rate according to the channel conditions to reduce the communication energy. Our results show that energy savings of up to 30% can be obtained with a reduction of barely 0.1 dB on the average video quality. The impact of feedback delays is shown to be small. In addition, this adaptive mechanism has low complexity, which makes it suitable for real-time applications.  相似文献   

SPIRAL OF DISAPPOINTMENT: DECLINE IN ACHIEVEMENT AMONG GIFTED ADOLESCENTS     

Wilhelm Wieczerkowski  Tania M. Prado 《High Ability Studies》1993,4(2):126-141

The view that the pattern of development and the scholastic performance of potentially highly gifted children are as prone to disturbances as those of less gifted youngsters is now widely accepted. The emergence of giftedness and the unfolding of talent has been shown to be a developmental process, in which a variety of cognitive, noncognitive, and ecopsychological preconditions are involved. Whether the observed developmental patterns of a young person are harmonious or disruptive depends on what has been described in the literature as a favourable (vs. unfavourable) constellation of facilitating factors. With the help of a dynamic model, case studies of failure and refusal to perform in school among young underachievers are analyzed and related to previous school experiences.  相似文献   

Prediction of self-reported knowledge with over-claiming, fluid and crystallized intelligence and typical intellectual engagement     

Gizem Hülür  Oliver Wilhelm  Stefan Schipolowski 《Learning and individual differences》2011,21(6):742-746

We investigated the usefulness of the Over-Claiming Questionnaire (OCQ) as a measure of cognitive abilities. In OCQs respondents are asked to rate their familiarity with items of academic or everyday knowledge (Paulhus, Harms, Bruce, & Lysy, 2003). Some items exist in reality (reals), and others do not (foils). We developed four OCQs, each consisting of 40 reals and 8 foils from the domains of Science, Humanities and Civics. The OCQs were administered in a longitudinal rotation design to 112 participants who attended the 9th school grade at the beginning of the study. In latent variable regression analyses 53% of variation in the reals could be explained by fluid and crystallized intelligence and over-claiming as indicated by responses to foils. Further variation in responses to reals and foils was explained by intellectual engagement. Our results show that self-reported knowledge, although positively related to measures of ability, to a large extent reflects over-claiming.  相似文献