206892687
Recycled path routing in mobile ad hoc networks
In mobile ad hoc networks, many routing algorithms rely on some form of flooding to accomplish the route discovery process. Flooding, however, consumes many valuable network resources such as time, bandwidth, and power. Most current routing schemes expire valid routes after a time period to account for nodal movement. This paper proposes a new route discovery method, called recycled path routing (RPR), which directs broadcasts toward the destination node even in the absence of location information. The recycled path routing scheme reduces the search space for the destination node by implementing an expired route cache that is utilized by each node in the network. Routes are added to the expired route cache as they expire from the active route cache and remain there until some time interval has passed or a new route has been discovered. Since these expired routes can provide valuable insight into finding new routes, RPR uses them to direct broadcasts toward the destination node. RPR can save a significant quantity of valuable network resources because only nodes near the optimal path will rebroadcast route requests.
38077943
Position-Based Topology-Independent Scheduling Algorithms for Mobile Ad Hoc Networks
5331573
All-to-All Broadcasting in Faulty Hypercubes
A new fault-tolerant all-to-all broadcasting algorithm in an n-dimensional hypercube with up to [n/2] faulty links is given. An extension of this algorithm that can tolerate up to [n/2] faulty nodes is also described. These algorithms assume a multiport I/O model, meaning each node can send and receive messages from all its adjacent nodes simultaneously. The total time steps taken by the proposed algorithms are near optimal, and they produce a factor of n less traffic than previously known algorithms.
42767167
Location Discovery in Ad Hoc Sensor Networks
34087964
Wormhole Routing in Faulty Mesh Networks
33219357
Fault-tolerant broadcasting in wormhole-routed torus networks
This paper describes a fault-tolerant broadcast algorithm for wormhole-routed torus networks for which there is only local knowledge of faulty components. This algorithm tolerates tip to k-1 faulty nodes in a k-ary n-cube provided the faults do not cause the network to be disconnected. Based on the fault-tolerant dimension-order unicast communication, this algorithm is deadlock-free and no additional virtual channels are needed. The first stage of this algorithm is itself an optimal broadcast algorithm for a torus if no faults are present. The second stage overcomes the presence of up to k-1 faults with a fixed number of additional message transmissions. Thus, the cost of this algorithm is within a constant factor of the cost of optimal non-fault-tolerant broadcast algorithms.
16557699
Disconnected Operation Service in Mobile Grid Computing
In this paper, we discuss on the extension of grid computing systems in mobile computing environments, where mobile devices can be effectively incorporated into the grid either as service recipients or as more valuable service providers. First, based on the present grid architecture, we try to figure out what would be the newly required services in such a mobile/grid integrated architecture. There are a number of challenging issues when taking mobile environment into account, such as intermittent connectivity, device heterogeneity, and weak security. Among these issues to solve, we particularly focus on a disconnected operation problem in this paper since mobile resources are prone to frequent disconnections due to their confined communication range and device mobility. We develop a new job scheduling algorithm for mobile grid system and evaluate it by various methods such as mathematical analysis, simulation, and prototype implementation.
9375021
Dynamic Data Grid Replication Strategy Based on Internet Hierarchy
In data grid, large quantity of data files is produced and data replication is applied to reduce data access time. Efficiently utilizing grid resources becomes important research issue since available resources in grid are limited while large number of workloads and large size of data files are produced. Dynamic replication in data grid aims to reduce data access time and to utilize network and storage resources efficiently. This paper proposes a novel dynamic replication strategy, called BHR, which reduces data access time by avoiding network congestions in a data grid network. With BHR strategy, we can take benefits from ‘network-level locality’ which represents that required file is located in the site which has broad bandwidth to the site of job execution. We evaluate BHR strategy by implementing it in an OptorSim, a data grid simulator initially developed by European Data Grid Projects. The simulation results show that BHR strategy can outperform other optimization techniques in terms of data access time when hierarchy of bandwidth appears in Internet. BHR extends current site-level replica optimization study to the network-level.
34137561
Using Relevance Feedback and Ranking in Interactive Searching
We present results of a study in which 50 searchers, of varying degrees of experience in information retrieval (IR), each performed searches on two TREC-4 adhoc interactive track topics, using a simple interface to the INQUIRY retrieval engine. The foci of our study were : the relationships between the users'models and experience of IR, and their performance in the TREC-4 adhoc task while using a best-match IR system with relevance feedback ; the understanding, use and utility of relevance feedback and ranking in interactive IR ; and, the evaluation of interactive IR.
17579236
Adaptive topology control for wireless Ad hoc networks
Topology control in ad-hoc networks is the problem of adjusting the transmission power at network nodes in order to achieve the optimal topology that maximizes network performance. Recently, using effective topology control to optimize energy usage in the network has come into focus in the research community [1, 2]. The common thesis arrived at by existing works is that the transmission range used by mobile nodes should be the minimum required to keep the network connected. We refer to such a topology as the minimally connected topology in the rest of the paper. We argue in this work that the minimally connected topology does not always provide the optimal performance in typical ad-hoc networks. We show that in contrast, for typical ad-hoc networks with a few hundred nodes distributed over a few square miles area, the optimal topology is a function of the traffic load.
13915681
Capturing and animating skin deformation in human motion
During dynamic activities, the surface of the human body moves in many subtle but visually significant ways: bending, bulging, jiggling, and stretching. We present a technique for capturing and animating those motions using a commercial motion capture system and approximately 350 markers. Although the number of markers is significantly larger than that used in conventional motion capture, it is only a sparse representation of the true shape of the body. We supplement this sparse sample with a detailed, actor-specific surface model. The motion of the skin can then be computed by segmenting the markers into the motion of a set of rigid parts and a residual deformation (approximated first as a quadratic transformation and then with radial basis functions). We demonstrate the power of this approach by capturing flexing muscles, high frequency motions, and abrupt decelerations on several actors. We compare these results both to conventional motion capture and skinning and to synchronized video of the actors.