No abstract

No abstract

Platinum diselenide (PtSe2), a type-II Dirac semi-metal material, is a potential saturable absorber (SA) to generate visible pulsed lasers due to its prominent optoelectronic properties.

Puqian Bridge is located in a quake-prone area in an 8-degree seismic fortification intensity zone, and the design of the peak ground motion is the highest grade worldwide. Nevertheless, the seismic design of the pile foundation has not been evaluated with regard to earthquake damage and the seismic issues of the pile foundation are particularly noticeable. We conducted a large-scale shaking table test (STT) to determine the dynamic characteristic of the bridge pile foundation. An artificial mass model was used to determine the mechanism of the bridge pile-soil interaction, and the peak ground acceleration range of 0.15 g–0.60 g (g is gravity acceleration) was selected as the input seismic intensity. The results indicated that the peak acceleration decreased from the top to the bottom of the bridge pile and the acceleration amplification factor decreased with the increase in seismic intensity. When the seismic intensity is greater than 0.50 g, the acceleration amplification factor at the top of the pile stabilizes at 1.32. The bedrock surface had a relatively small influence on the amplification of the seismic wave, whereas the overburden had a marked influence on the amplification of the seismic wave and filtering effect. Damage to the pile foundation was observed at 0.50 g seismic intensity. When the seismic intensity was greater than 0.50 g, the fundamental frequency of the pile foundation decreased slowly and tended to stabilize at 0.87 Hz. The bending moment was larger at the junction of the pile and cap, the soft-hard soil interface, and the bedrock surface, where cracks easily occurred. These positions should be focused on during the design of pile foundations in meizoseismal areas.

Abstract-Epidemic protocols belong to a class of routing paradigm that have wide ranging applications in Delay TolerantNetworks (DTNs) due to their simplicity, low delays, and little to no reliance on special nodes. To this end, a comprehensive study of their performance will serve as an important guide to future protocol designers. Unfortunately, to date, there is no work that studies epidemic routing protocols using a common framework that evaluates their performance objectively using the same mobility model and parameters. To this end, we study four categories of epidemic routing protocols. Namely, P-Q epidemic, epidemic with Time-To-Live (TTL), epidemic with Encounter Count (EC) and epidemic with immunity table. Our results show that the probability of transmissions as used in P-Q epidemic may increase delay and decrease delivery ratio. Apart from that, an incorrect TTL value leads to premature discarding of bundles, and thereby, has a non negligible impact on delivery ratio. Epidemic with EC suffers from high buffer occupancy levels and long delivery delays. In addition, epidemic with immunity suffers from high overheads. Henceforth, we propose three enhancements: dynamic TTL, EC+TTL and cumulative immunity to address the aforementioned limitations. Our results show that dynamic TTL improves delivery ratio by more than 20%, EC+TTL reduces buffer occupancy level by 40%, and improve delivery ratio by at least 40% at high loads. Cumulative immunity reduces the buffer occupancy level of nodes by at least 15% whilst incuring an order of magnitude less signaling overheads.