No abstract

No abstract

The effects of adsorption of xenon to the thermal conductivity of a resorcinol-formaldehyde aerogel were investigated in a temperature range from 20 to 120 K. It was found that at temperatures below 75 K, the adsorbed xenon has little effect on the thermal conductivity. Rapid rises of the thermal conductivity develop at temperatures around 75-80 K with magnitudes roughly proportional to the amount of xenon adsorbed. The effect is explained as due to adsorbed xenon atoms that enhance the neck connection between aerogel particles.

No abstract

MPLS (Multi-Protocol Label Switching) networks allow multiple LSPs (Label-Switched Paths) be established froma source to a destination to satisfy throughput required by an application. Given a MPLS network, where each link is associated with a maximum available bandwidth, a fundamental traffic engineering problem is how we can find minimum number of paths to achieve the maximum throughput. Optimally solving this problem can save huge amount of valuable network resources including available lable space and reduce management complexity. This paper proves that finding a minimal number of LSPs is an NP-hard problem. To deal with this problem, we have studied four approximation algorithmes. We found from simulations that the average number of paths produced by all these algorithms grows quite slowly when the network grows large. Moreover, the two algorithms, Topological-Sort-Based Maximum-Path algorithm and Greedy-Based Maximum-Edge algorithm perform better than other algorithms. Between these two algorithms, the Greedy-Based Maximum-Edge algorithm is more time-efficient while keeps comparable performance.