The Pedaling Technique of Elite Endurance Cyclists: Changes with Increasing Workload at Constant Cadence

1991 ◽  
Vol 7 (1) ◽  
pp. 29-53 ◽  
Author(s):  
Steven A. Kautz ◽  
Michael E. Feltner ◽  
Edward F. Coyle ◽  
Ann M. Baylor
Keyword(s):  
Vertical Component ◽  
Horizontal Component ◽  
Applied Force ◽  
The Other ◽  
Total Work ◽  
External Work ◽  
High Workload ◽  
Work Done ◽  
Positive Work

A pedal dynamometer recorded changes in pedaling technique (normal and tangential components of the applied force, crank orientation, and pedal orientation) of 14 elite male 40-km time trialists who rode at constant cadence as the workload increased from similar to an easy training ride to similar to a 40-km competition. There were two techniques for adapting to increased workload. Seven subjects showed no changes in pedal orientation, and predominantly increased the vertical component of the applied force during the downstroke as the workload increased. In addition to increasing the vertical component during the downstroke, the other subjects also increased the toe up rotation of the pedal throughout the downstroke and increased the horizontal component between 0° and 90°. A second finding was that negative torque about the bottom bracket during the upstroke usually became positive (propulsive) torque at the high workload. However, while torque during the upstroke did reduce the total positive work required during the downstroke, it did not contribute significantly to the external work done because 98.6% and 96.3 % of the total work done at the low and high workloads, respectively, was done during the downstroke.

Galilean Relativity

2018 ◽  
Author(s):  
David M. Wittman
Keyword(s):  
Inertial Frame ◽  
Vertical Component ◽  
Horizontal Component ◽  
The Other ◽  
One Dimension ◽  
Everyday Experience ◽  
Low Speed ◽  
Principle Of Relativity ◽  
Galilean Relativity ◽  
Laws Of Motion

Galilean relativity is a useful description of nature at low speed. Galileo found that the vertical component of a projectile’s velocity evolves independently of its horizontal component. In a frame that moves horizontally along with the projectile, for example, the projectile appears to go straight up and down exactly as if it had been launched vertically. The laws of motion in one dimension are independent of any motion in the other dimensions. This leads to the idea that the laws of motion (and all other laws of physics) are equally valid in any inertial frame: the principle of relativity. This principle implies that no inertial frame can be considered “really stationary” or “really moving.” There is no absolute standard of velocity (contrast this with acceleration where Newton’s first law provides an absolute standard). We discuss some apparent counterexamples in everyday experience, and show how everyday experience can be misleading.

Visual Illusion in Lengths of Words: An Old Friend in Disguise

1968 ◽  
Vol 23 (3) ◽  
pp. 932-934
Author(s):  
Glenn A. Moyer ◽  
W. H. Tedford
Keyword(s):  
Visual Illusion ◽  
Vertical Component ◽  
Horizontal Component ◽  
The Other ◽  
Visual Distortion ◽  
Apparent Length ◽  
The Difference

Pairs of words containing the same numbers of letters were found to differ in apparent length if one member of the pair contained all short letters while the other contained some tall letters such as b or l. It was hypothesized that the difference was due to a visual distortion whereby the horizontal component of a word appeared to be shortened when its vertical component was increased.

Peripheral representation of antennal orientation by the scapal hair plate of the cockroach Periplaneta americana

2001 ◽  
Vol 204 (24) ◽  
pp. 4301-4309 ◽  
Author(s):  
J. Okada ◽  
Y. Toh
Keyword(s):  
Single Unit ◽  
Periplaneta Americana ◽  
Vertical Component ◽  
Horizontal Component ◽  
Vertical Position ◽  
Horizontal Position ◽  
Joint Movement ◽  
Basal Segment ◽  
Dynamic Phase ◽  
Hair Sensilla

SUMMARY Arthropods have hair plates that are clusters of mechanosensitive hairs, usually positioned close to joints, which function as proprioceptors for joint movement. We investigated how angular movements of the antenna of the cockroach (Periplaneta americana) are coded by antennal hair plates. A particular hair plate on the basal segment of the antenna, the scapal hair plate, can be divided into three subgroups: dorsal, lateral and medial. The dorsal group is adapted to encode the vertical component of antennal direction, while the lateral and medial groups are specialized for encoding the horizontal component. Of the three subgroups of hair sensilla, those of the lateral scapal hair plate may provide the most reliable information about the horizontal position of the antenna, irrespective of its vertical position. Extracellular recordings from representative sensilla of each scapal hair plate subgroup revealed the form of the single-unit impulses in response to hair deflection. The mechanoreceptors were characterized as typically phasic-tonic. The tonic discharge was sustained indefinitely (>20 min) as long as the hair was kept deflected. The spike frequency in the transient (dynamic) phase was both velocity- and displacement-dependent, while that in the sustained (steady) phase was displacement-dependent.

COMPUTING THE RUPTURE DEGREE IN COMPOSITE GRAPHS

2010 ◽  
Vol 21 (03) ◽  
pp. 311-319 ◽  
Author(s):  
AYSUN AYTAC ◽  
ZEYNEP NIHAN ODABAS
Keyword(s):  
Complete Graph ◽  
Connected Graph ◽  
The Other ◽  
Trade Off ◽  
Number Of Components ◽  
Np Complete ◽  
Work Done ◽  
Better Than

The rupture degree of an incomplete connected graph G is defined by [Formula: see text] where w(G - S) is the number of components of G - S and m(G - S) is the order of a largest component of G - S. For the complete graph Kn, rupture degree is defined as 1 - n. This parameter can be used to measure the vulnerability of a graph. Rupture degree can reflect the vulnerability of graphs better than or independent of the other parameters. To some extent, it represents a trade-off between the amount of work done to damage the network and how badly the network is damaged. Computing the rupture degree of a graph is NP-complete. In this paper, we give formulas for the rupture degree of composition of some special graphs and we consider the relationships between the rupture degree and other vulnerability parameters.

scholarly journals Comparison between sprinkler irrigation and natural rainfall based on droplet diameter

2016 ◽  
Vol 14 (1) ◽  
pp. e1201 ◽  
Author(s):  
MaoSheng Ge ◽  
Pute Wu ◽  
Delan Zhu ◽  
Daniel P. Ames
Keyword(s):  
Soil Erosion ◽  
Kinetic Energy ◽  
Droplet Diameter ◽  
Vertical Component ◽  
Radial Distance ◽  
Sprinkler Irrigation ◽  
Application Rate ◽  
Horizontal Component ◽  
Natural Rainfall ◽  
Actual Field

<p>An indoor experiment was conducted to analyze the movement characteristics of different sized droplets and their influence on water application rate distribution and kinetic energy distribution. Radial droplets emitted from a Nelson D3000 sprinkler nozzle under 66.3, 84.8, and 103.3 kPa were measured in terms of droplet velocity, landing angle, and droplet kinetic energy and results were compared to natural rainfall characteristics. Results indicate that sprinkler irrigation droplet landing velocity for all sizes of droplets is not related to nozzle pressure and the values of landing velocity are very close to that of natural rainfall. The velocity horizontal component increases with radial distance while the velocity vertical component decreases with radial distance. Additionally, landing angle of all droplet sizes decreases with radial distance. The kinetic energy is decomposed into vertical component and horizontal component due to the oblique angles of droplet impact on the surface soil, and this may aggravate soil erosion. Therefore the actual oblique angle of impact should be considered in actual field conditions and measures should be taken for remediation of soil erosion if necessary.</p>

Single-station SVD-based polarization filtering of ground roll: Perfection and investigation of limitations and pitfalls

Geophysics ◽  
2012 ◽  
Vol 77 (2) ◽  
pp. V41-V59 ◽  
Author(s):  
Olena Tiapkina ◽  
Martin Landrø ◽  
Yuriy Tyapkin ◽  
Brian Link
Keyword(s):  
Time Window ◽  
Synthetic Data ◽  
Vertical Component ◽  
Horizontal Component ◽  
Frequency Bandwidth ◽  
Polarization Filter ◽  
Data Set ◽  
Single Station ◽  
Ground Roll ◽  
Polarization Filtering

The advent of single receiver point, multi-component geophones has necessitated that ground roll be removed in the processing flow rather than through acquisition design. A wide class of processing methods for ground-roll elimination is polarization filtering. A number of these methods use singular value decomposition (SVD) or some related transformations. We focus on a single-station SVD-based polarization filter that we consider to be one of the best in the industry. The method is comprised of two stages: (1) ground-roll detection and (2) ground-roll estimation and filtering. To detect the ground roll, a special attribute dependent on the singular values of a three-column matrix formed by a sliding time window is used. The ground roll is approximated and subtracted using the first two eigenimages of this matrix. To limit the possible damage to the signal, the filter operates within the record intervals where the ground roll is detected and within the ground-roll frequency bandwidth only. We improve the ground-roll detector to make it theoretically insensitive to ambient noise and more sensitive to the presence of ground roll. The advantage of the new detector is demonstrated on synthetic and field data sets. We estimate theoretically and with synthetic data the attenuation of the underlying reflections that can be caused by the polarization filter. We show that the underlying signal always loses almost all the energy on the vertical component and on the horizontal component in the ground-roll propagation plane and within the ground-roll frequency bandwidth. The only signal component, if it exists, that can retain a significant part of its energy is the horizontal component orthogonal to the above plane. When 2D 3C field operations are conducted, the signal particle motion can deviate from the ground-roll propagation plane and can therefore retain some of its energy due to a set of offline reflections. In the case of 3D 3C seismic surveys, the reflected signal always deviates from the ground-roll propagation plane on the receiver lines that do not contain the source. This is confirmed with a 2.5D 3C synthetic data set. We discuss when the ability of the filter to effectively subtract the ground roll may, or may not, allow us to ignore the inevitable harm that is done to the underlying reflected waves.

Born idolaters: The limits of the philosophical implications of the cognitive science of religion

2015 ◽  
Vol 57 (2) ◽  
Author(s):  
Jonathan Jong ◽  
Christopher Kavanagh ◽  
Aku Visala
Keyword(s):  
Cognitive Science ◽  
Religious Belief ◽  
Empirical Work ◽  
The Other ◽  
Human Beings ◽  
Cognitive Science Of Religion ◽  
Philosophical Work ◽  
Cognitive Constraints ◽  
Science Of Religion ◽  
Work Done

SummaryIn recent years, theoretical and empirical work done under the rubric of the cognitive science of religion (CSR) have led many to conclude that religion (or, at least, some aspects thereof) is “natural”. By this, it is meant that human beings are predisposed to believe in supernatural agents, and that their beliefs about these agents are constrained in various ways. The details about how and why these predispositions and cognitive constraints developed and evolved are still largely unknown, though there is enough of a theoretical consensus in CSR for philosophers to have begun reflecting on the implications of CSR for religious belief. In particular, much philosophical work has been done on the implications of CSR for theism, on both sides of the debate. On one hand, CSR might contribute to defeating particular arguments for theism, or indeed theism altogether; on the other hand, CSR might provide support for specific theological views. In this paper, we argue that the CSR is largely irrelevant for

External work and potential for elastic storage at the limb joints of running dogs

1998 ◽  
Vol 201 (23) ◽  
pp. 3197-3210 ◽  
Author(s):  
C. S. Gregersen ◽  
N. A. Silverton ◽  
D. R. Carrier
Keyword(s):  
Elastic Energy ◽  
Elastic Strain ◽  
Strain Energy ◽  
Elastic Strain Energy ◽  
External Work ◽  
Negative Work ◽  
Extensor Muscles ◽  
Positive Work

The storage and recovery of elastic strain energy in muscles and tendons increases the economy of locomotion in running vertebrates. In this investigation, we compared the negative and positive external work produced at individual limb joints of running dogs to evaluate which muscle-tendon systems contribute to elastic storage and to determine the extent to which the external work of locomotion is produced by muscles that shorten actively rather than by muscles that function as springs. We found that the negative and positive external work of the extensor muscles is not allocated equally among the different joints and limbs. During both trotting and galloping, the vast majority of the negative work was produced by the two distal joints, the wrist and ankle. The forelimb produced most of the negative work in both the trot and the gallop. The hindlimb produced most of the positive work during galloping, but not during trotting. With regards to elastic storage, our results indicate that the forelimb of dogs displays a greater potential for storage and recovery of elastic energy than does the hindlimb. Elastic storage appears to be more important during trotting than during galloping, and elastic storage appears to be more pronounced in the extensor muscles of the distal joints than in the extensor muscles of the proximal joints. Furthermore, our analysis indicates that a significant portion of the external work of locomotion, 26% during trotting and 56 % during galloping, is produced by actively shortening muscles. We conclude that, although elastic storage of energy is extremely important to the economy of running gaits, actively shortening muscles do make an important contribution to the work of locomotion.

Using Concept Mapping to Improve the Quality of Learning

2010 ◽  
pp. 316-336
Author(s):  
Maria Luisa Pérez Cabaní ◽  
Josep Juandó Bosch
Keyword(s):  
Concept Mapping ◽  
Learning Strategies ◽  
Concept Maps ◽  
The Other ◽  
The European Union ◽  
Quality Of Learning ◽  
European Higher Education ◽  
The One ◽  
Work Done

The European Higher Education Area, created to contribute to the development of quality education and encourage cooperation between Member States of the European Union, has created an opportunity for reflection on teaching methods in universities. These circumstances provide momentum for the use of learning strategies. Along these lines, this chapter presents work done on concept mapping, one of the methods that could significantly help prepare both students and teachers for the new roles expected of them. The results of two lines of study are presented: on the one hand, research that analyses the influence of the differential use of concept maps on the quality of learning; and on the other, an innovation in the use of concept maps in a course developed in the area of initial teacher training. Both initiatives serve to highlight increased interest in concept mapping in the field of learning and especially in collaborative learning.

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