scholarly journals Comparison of the classical variation coefficient with calculated with the ring method for survey BOST results

2016 ◽  
Vol 11 ◽  
pp. 22-25
Author(s):  
Stanisław Borkowski ◽  
Agnieszka Noga
Keyword(s):  
Variation Coefficient ◽  
Ring Method ◽  
Classical Variation

Development of an Evaluation Model of Freeway Traffic Safety Facilities System

2013 ◽  
Vol 734-737 ◽  
pp. 1578-1581
Author(s):  
Yan Yong Guo ◽  
Yao Wu ◽  
Liang Song ◽  
Hui Duan
Keyword(s):  
Traffic Safety ◽  
Evaluation System ◽  
Evaluation Model ◽  
Variation Coefficient ◽  
Freeway Traffic ◽  
Evaluation Result ◽  
Single Index ◽  
Recognition Theory ◽  
Attribute Measure ◽  
Attribute Recognition

This study developed an evaluation model of freeway traffic safety facilities system. Firstly, an evaluation system of freeway traffic safety facility was proposed. Secondly, an evaluation model was proposed based on attribute recognition theory. And the evaluation result was identified according to the attribute measure value of single index and the comprehensive attribute measure value of multiple indexes as well as the confidence criterion. Thirdly, the weight of each indicator was decided by variation coefficient. Finally, A case of TAI-GAN freeway (K1+242~K3+259 segment) was conducted to verify the feasibility and effectiveness of the model.

scholarly journals Impact or push-off lameness presentation is not altered by the type of track surface where horses are trotted

2015 ◽  
Vol 67 (6) ◽  
pp. 1475-1482 ◽  
Author(s):  
M.S. Azevedo ◽  
F.D.D.L. Côrte ◽  
K.E. Brass ◽  
M. Gallio ◽  
S.L Dau ◽  
...  
Keyword(s):  
Inertial Sensors ◽  
Concrete Surface ◽  
Variation Coefficient ◽  
Soft Ground ◽  
Loose Sand ◽  
Significance Level ◽  
Tukey Test ◽  
Minimum Height ◽  
Track Surface ◽  
Vector Sum

This study aimed to evaluate the influence of the track surface on which horses are examined, regarding the phase of lameness presentation. Ten horses with lameness in at least one limb were evaluated with wireless inertial sensors on three track surfaces (concrete, loose sand and grass). Six crossover track sequences were established. The variables vector sum, maximum and minimum height of the head and pelvis, variation coefficient of the maximum and minimum height of the head and pelvis were analyzed using ANOVA, followed by Tukey test to compare means between track surface and sequence, at 5% significance level. The lameness phase (impact or pushoff) was analyzed considering the proportion of affected animals. There were no differences on vector sum, maximum and minimum height or variation coefficient of head and pelvis. Difference was observed on the number of strides registered on sand compared to grass and concrete (p <0.0001) for fore and hindlimbs. Impact lameness on forelimbs was presented by a larger number of animals on the concrete surface; pushoff lameness was more evident on the grass surface. In the hindlimbs, impact lameness was more evident on the grass surface, while pushoff lameness was in greater number of animals on concrete surfaces. The track sequence on which horses were trotted during evaluation does not seem to be a factor, but the number of lame horses and the phase of lameness manifestation can vary between track surfaces, as some horses showed impact lameness on soft ground and elevation lameness on hard ground.

The Dependence of the Friction Coefficient on the Size and Course of Sliding Speed

2014 ◽  
Vol 693 ◽  
pp. 305-310 ◽  
Author(s):  
Eva Labašová
Keyword(s):  
Friction Coefficient ◽  
Normal Load ◽  
Testing Machine ◽  
Current Component ◽  
Sliding Speed ◽  
Rectangular Shape ◽  
Coefficient Increase ◽  
The Coefficient Of Friction ◽  
Ring Method ◽  
Run Up

The coefficient of friction for the bronze material (CuZn25Al6) with insert graphite beds and other bronze material (CuSn12) are investigated in this paper. Friction coefficient was investigated experimentally by the testing machine Tribotestor`89 which uses the principle of the ring on ring method. The external fixed bushing was exposed to the normal load of the same size in all tests. Process of load was increased from level 50 N to 600 N during run up 300 s, after the run up the appropriate level of load was held. The internal bushing performed a rotational movement with constant sliding speed. The value of sliding speed was changed individually for every sample (v = 0.2 (0.3, 0.4) m.s-1). The forth test had a rectangular shape of sliding speed with direct current component 0.3 m.s-1 and the amplitude 0.1 m.s-1 period 300 s, the whole test took 2100 s. The obtained results reveal that friction coefficient increase with the increase of sliding speed.

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