A 2-micron pulsed, Integrated Path Differential Absorption (IPDA) lidar instrument for ground and airborne atmospheric CO2 concentration measurements via direct detection method is being developed at NASA Langley Research Center. This instrument will provide an alternate approach to measure atmospheric CO2 concentrations with significant advantages. A high energy pulsed approach provides highpr...

AMUact--No single optimization method exists that is best suited to solve all path generation problems effectively [Erdman 1991]. Graphical illustrations of the mechanism design space, given in this paper, attest to the difficulties encountered in the optimization of path generation tasks. An example has also been provided to illustrate the importance of a good initial guess in achieving proper...

This paper analytically examines two vibration paths rank ordering methods and critically investigates several path identification issues. One method is the indirect interfacial path force estimation procedure that is employed in the well known experimental transfer path analysis. The other method is path disconnect scheme that has been historically utilized in industry to empirically find a do...

Recent studies have demonstrated the utility of alternate paths in improving connectivity of two end hosts. However studies that comprehensively evaluate the tradeoff between its effectiveness and overhead are lacking. In this paper we carefully characterize and evaluate the trade-off between (1) the efficacies of alternate path routing in improving end-to-end delay and loss, and (2) the overhe...

In nonhierarchical circuit-switched networks, calls can be routed to alternate paths if the direct path is blocked. In this paper, we analyze two alternate-path routing rules called the Madmum Free Circuit routing and the Madmum Free Circuit with Minimm Occupied channel routing. For convenience, we shall call them the M and M2 routings respectively. In the use ofMrouting, acall isrouted toanalt...

We have calculated, quantitatively, the time decay of donor-acceptor pair luminescence in compensated semiconductors, incorporating the effect of the potential fluctuations which exist in such materials. We show that the often-reported stretched-exponential decay law can here be derived rigorously, but only to a very close approximation, and, moreover, only provided that there is an alternate, ...

Due to the way BGP paths are distributed over iBGP sessions inside an Autonomous System (AS), a BGP withdraw that follows a failure may be propagated outside the AS although other routers of the AS know a valid alternate path. This causes transient losses of connectivity and contributes to the propagation of a large number of unnecessary BGP messages. In this paper, we show, based on RouteViews...

Mobile ad hoc network (MANET) is characterized as a dynamic, multi-hop wireless self-organized distributed ad hoc network. Because of node mobility and power limitation, the network topology changes frequently which leads to path breakage. Hence a dynamic routing protocol is required for ad hoc networks to function properly. Reactive on -demand routing protocols becomes very popular because it ...

This paper proposes an autonomous inspection method for steel box girders that uses a wall-climbing robot instead of human workers. According to the 3D operating environment inside girder, path traverse positions be inspected. The comprises two alternate sections lane’s centerline and U-shaped steering. To realize robot’s tracking desired path, kinematics analysis based on different poses durin...