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In view of the lack of an effective evaluation model for optical network survivability evaluation caused by geographical disasters, this paper has studied and proposed an evaluation model for optical network survivability considering geographical disasters, designed and proposed an evaluation index for survivability based on communication efficiency. On this basis, a survivability assessment method considering protection and unprotected conditions is proposed. Simulation results show that this method can effectively evaluate the invulnerability of optical networks under geographical disasters.

Reindeer (Rangifer tarandus) have lengthy seasonal migrations on land and their feet possess excellent locomotor characteristics that can adapt to complex terrains. In this study, the kinematics and vertical ground reaction force (GRF) of reindeer forelimb joints (interphalangeal joint b, metacarpophalangeal joint c, and wrist joint d) under walk, trot 1, and trot 2 were measured using a motion tracking system and Footscan pressure plates. Significant differences among different locomotor activities were observed in the joint angles, but not in changes of the joint angles (αb, αc, αd) during the stance phase. Peak vertical GRF increased as locomotor speed increased. Net joint moment, power, and work at the forelimb joints were calculated via inverse dynamics. The peak joint moment and net joint power related to the vertical GRF increased as locomotor speed increased. The feet absorbed and generated more energy at the joints. During different locomotor activities, the contribution of work of the forelimbs changed with both gait and speed. In the stance phase, the metacarpophalangeal joint absorbed more energy than the other two joints while trotting and thus performed better in elastic energy storage. The joint angles changed very little (∼5°) from 0 to 75% of the stance phase, which reflected the stability of reindeer wrist joints. Compared to typical ungulates, reindeer toe joints are more stable and the stability and energy storage of forelimb joints contribute to locomotor performance in reindeer.

The Internet has been a main method of image's transmission and storage. A significative problem is how to prevent illegal diffusion for some images. In this paper, we prefer an effective method of registering the decode program with the user's identity by which the installation procedure produces the registering number with processed chaotic sequence or random sequences.