Interactions between disruptive colouration and the match between prey and background spot size were manipulated in two experiments that used time taken by human ＇predators＇ to find artificial prey （virtual crab mo...Interactions between disruptive colouration and the match between prey and background spot size were manipulated in two experiments that used time taken by human ＇predators＇ to find artificial prey （virtual crab morphs） against heterogeneous backgrounds as a measure of the their camouflage. Experiment 1, in which the spots and their placement imitated the arrangement on the crab Carcinus maenas, tested whether high and low contrast spots touching the body outline （disruptive ＇edge＇ morphs） made the artificial prey more difficult to detect than when the spots did not touch the outline （non-disruptive ＇inner＇ morphs） against three different backgrounds： ＇small＇, ＇middle＇ and ＇large＇ spot size. In Experiment 2, the range of spot sizes and their positions （＇edge＇ and ＇inner＇） on the crab morphs were varied to determine the most effective combination against the ＇mid- dle＇ background. Altogether, 640 volunteers participated in these computer trials, representing a high degree of independent replication. All patterned morphs were significantly harder to detect than plain morphs, indicating that possessing at least some degree of background matching can provide camouflage. Both experiments demonstrated that various morphs, though not having the same spot sizes as the background, had similar or better survivorship as those with matching spot sizes--indicating that opti- mal camouflage did not come from background matching alone. In Experiment 2, edge-disrupted morphs consistently took longer to find than their non-disruptive counterparts. The relative effects of edge disruption, contrast, and background/prey spot size are clearly context-dependent, highlighting the complexity of prey concealment [Current Zoology 61 （4）： 718-728, 2015].展开更多
The authors study the use of the virtual element method(VEM for short) of order k for general second order elliptic problems with variable coefficients in three space dimensions. Moreover, they investigate numerically...The authors study the use of the virtual element method(VEM for short) of order k for general second order elliptic problems with variable coefficients in three space dimensions. Moreover, they investigate numerically also the serendipity version of the VEM and the associated computational gain in terms of degrees of freedom.展开更多
Integral imaging is a three dimensional(3D)display technology without any additional equipment.A new system is proposed in this paper which consists of the elemental images of real images in real mode(RIRM)and the one...Integral imaging is a three dimensional(3D)display technology without any additional equipment.A new system is proposed in this paper which consists of the elemental images of real images in real mode(RIRM)and the ones of virtual images in real mode(VIRM).The real images in real mode are the same as the conventional integral images.The virtual images in real mode are obtained by changing the coordinates of the corresponding points in elemental images which can be reconstructed by the lens array in virtual space.In order to reduce the spot size of the reconstructed images,the diffuser in conventional integral imaging is given up in the proposed method.Then the spot size is nearly1/20 of that in the conventional system.And an optical integral imaging system is constructed to confirm that our proposed method opens a new way for the application of the passive 3D display technology.展开更多
文摘Interactions between disruptive colouration and the match between prey and background spot size were manipulated in two experiments that used time taken by human ＇predators＇ to find artificial prey （virtual crab morphs） against heterogeneous backgrounds as a measure of the their camouflage. Experiment 1, in which the spots and their placement imitated the arrangement on the crab Carcinus maenas, tested whether high and low contrast spots touching the body outline （disruptive ＇edge＇ morphs） made the artificial prey more difficult to detect than when the spots did not touch the outline （non-disruptive ＇inner＇ morphs） against three different backgrounds： ＇small＇, ＇middle＇ and ＇large＇ spot size. In Experiment 2, the range of spot sizes and their positions （＇edge＇ and ＇inner＇） on the crab morphs were varied to determine the most effective combination against the ＇mid- dle＇ background. Altogether, 640 volunteers participated in these computer trials, representing a high degree of independent replication. All patterned morphs were significantly harder to detect than plain morphs, indicating that possessing at least some degree of background matching can provide camouflage. Both experiments demonstrated that various morphs, though not having the same spot sizes as the background, had similar or better survivorship as those with matching spot sizes--indicating that opti- mal camouflage did not come from background matching alone. In Experiment 2, edge-disrupted morphs consistently took longer to find than their non-disruptive counterparts. The relative effects of edge disruption, contrast, and background/prey spot size are clearly context-dependent, highlighting the complexity of prey concealment [Current Zoology 61 （4）： 718-728, 2015].
文摘The authors study the use of the virtual element method(VEM for short) of order k for general second order elliptic problems with variable coefficients in three space dimensions. Moreover, they investigate numerically also the serendipity version of the VEM and the associated computational gain in terms of degrees of freedom.
基金supported by the National Natural Science Foundation of China(No.11474169)
文摘Integral imaging is a three dimensional(3D)display technology without any additional equipment.A new system is proposed in this paper which consists of the elemental images of real images in real mode(RIRM)and the ones of virtual images in real mode(VIRM).The real images in real mode are the same as the conventional integral images.The virtual images in real mode are obtained by changing the coordinates of the corresponding points in elemental images which can be reconstructed by the lens array in virtual space.In order to reduce the spot size of the reconstructed images,the diffuser in conventional integral imaging is given up in the proposed method.Then the spot size is nearly1/20 of that in the conventional system.And an optical integral imaging system is constructed to confirm that our proposed method opens a new way for the application of the passive 3D display technology.
