Different effects of spatial separation in action and perception

Spatial distance of response keys has been shown to have an effect on nonspatial tasks in that performance improved if the spatial distance increased. Comparably, spatial distance of stimulus features has been shown to have a performance-improving effect in a (partly) spatial task. Here, we combined these two findings in the same task to test for the commonality of the effect of stimulus distance and the effect of response distance. Thus, we varied spatial distance in exactly the same fashion either between stimuli or between responses in a standard Eriksen flanker task. The results show that spatial distance only affected the processing of stimulus features, while it had no effect on the processing of response features. Regarding the idea of common coding of action and perception (Prinz, 1990), stimulus and response processing should be influenced by spatial distance in the same way so that our data might suggest a boundary for the idea of common coding.

Mining-Induced Damage Characteristics of Floors during Fully Mechanized Caving Mining: A Case Study

To study the mining-induced damage characteristics of floors during fully mechanized mining, in situ measurements were performed using the hollow inclusion strain sensors in the No. 100502 (80 m, 180 m) mining face of the Yitang Coal Mine in the Huoxi coal field in the Shanxi Province of China. The in situ measurement results show that the failure depths of the floor rocks in the 100502 (80 m) and 100502 (180 m) mining faces were 12.50∼14.65 m and 17.50∼19.20 m, respectively. The longer the mining face was, the greater the failure depth and the more severe the deformation and damage of the floor rocks were. The failures of the damaged floor rocks can be divided into two types: pull-pressure strain mutations and abnormal mutations. With the advancement of the mining face, the strain increments of floor rocks at different buried depths showed obvious advanced and lagged responses. Specifically, the advanced response distance decreased with a negative exponential trend, while the lagged response distance generally first increased and then decreased as the depth increased. The results can not only provide important guidance to coal mining under water pressure, but also offer a key theoretical reference for failure depth control of floor rocks under similar geophysical conditions.

Experimental study of the transient motion of floats reproducing floating wood in rivers

The flow of large wood among hydraulic structures in rivers, especially in urban areas, can cause many problems. Despite many statistical, morphological and hydrodynamical studies on this phenomenon, little information is available on the transient motion of floating wood pieces. In this study, we investigate theoretically and experimentally the transient motion of floating particles under a simple acceleration. From a standard advection model we identify a particle characteristic response distance to the flow, noted λ. This key parameter is then measured for different floating particles reproducing wood in rivers (logs without and with idealized roots). We show here the typical value of this parameter as a function of particle streamwise body length for different particle geometries. The influence of roots can be well captured by an equivalent frontal area, regardless of the root pattern. This response distance could provide useful information on the probability of impact on hydraulic structures depending on the floating wood characteristics.