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.
6873960
A scalable approach for reliable downstream data delivery in wireless sensor networks
There exist several applications of sensor networks wherere liability of data delivery can be critical. While the redundancy inherent in a sensor network might increase the degree of reliability, it by no means can provide any guaranteed reliability semantics. In this paper, we consider the problem of reliable sink-to-sensors data delivery. We first identify several fundamental challenges that need to be addressed, and are unique to a wireless sensor network environment. We then propose a scalable framework for reliable downstream data delivery that is specifically designed to both address and leverage the characteristics of a wireless sensor network, while achieving the reliability in an efficient manner. Through ns2 based simulations, we evaluate the proposed framework.
16093001
Textiles and computing: background and opportunities for convergence
John Kay's invention of the flying shuttle in 1733 sparked the first Industrial Revolution, which led to the transformation of industry and subsequently of civilization itself. Yet another invention in the field of textiles - the Jacquard head by Joseph Marie Jacquard (circa 1801) - was the first binary information processor. At any given point, the thread in a woven fabric can be in one of two states or positions: on the face of the fabric or on the back. Pattern cards were punched or cut according to the required fabric design. A hole in the card signified that the thread would appear on the face of the fabric, while a blank meant that the end would be left down and appear on the back of the fabric. The Jacquard head was used on the weaving loom or machine for raising and lowering the warp threads to form desired patterns based on the lifting plan or program embedded in the cards. Thus the Jacquard mechanism set the stage for modern day binary information processing. Ada Lovelace, the benefactor for Charles Babbage who worked on the Analytical Engine (the predecessor to the modern day computer), is said to have remarked, "The Analytical Engine weaves algebraic patterns just as the Jacquard loom weaves flowers and leaves." The Jacquard mechanism that inspired Babbage and spawned the Hollerith punched card has been instrumental in bringing about one of the most profound technological advancements known to humans, viz., the second Industrial Revolution also known as the Information Processing Revolution [1]. In fact, when Intel introduced its Pentium class of microprocessors, one of the advertisements had a "fabric of chips" emerging from a weaving machine; this picture eloquently captured the essence of chip making - a true blending of art and science - much like the design and production of textiles.
1204013
An interactive speech interface for summarizing agile project planning meetings
In this paper we present an autonomous meeting summarizer that transcribes an agile planning meeting and produces a textual summary of the discussion. We explore the issues involved in designing a speech-based interactive system that communicates with humans in a natural language. The inherent nature of ambiguity in conversational speech is overcome by suggesting a list of possible phrases to listen for. The system interacts with users in an interview-style dialogue for data collections. This is possible because we used the highly constrained structure and terminologies of agile planning meetings to make the approach successful.
29785948
Fast Replacement Route Discovery in Location-Aided Mobile Ad hoc Networks
16000094
On-line motion blending for real-time locomotion generation
In this paper, we present an integrated framework of on-line motion blending for locomotion generation. We first provide a novel scheme for incremental timewarping, which always guarantees that the time goes forward. Combining the idea of motion blending with that of posture rearrangement, we introduce a motion transition graph to address on-line motion blending and transition simultaneously. Guided by a stream of motion specifications, our motion synthesis scheme moves from node to node in an on-line manner while blending a motion at a node and generating a transition motion at an edge. For smooth on-line motion transition, we also attach a set of example transition motions to an edge. To represent similar postures consistently, we exploit the inter-frame coherency embedded in the input motion specification. Finally, we provide a comprehensive solution to on-line motion retargeting by integrating existing techniques. Copyright © 2004 John Wiley & Sons, Ltd.
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.