14874981
On the performance of a dual round-robin switch
The dual round-robin matching (DRRM) switch has a scalable, low complexity architecture which allows for an aggregate bandwidth exceeding 1 Tb/s using current CMOS technology. In this paper we prove that the DRRM switch can achieve 100% throughput under i.i.d. and uniform traffic. The DRRM is the first practical matching scheme for which this property has been proved. The performance of the DRRM switch is then studied and compared with the iSLIP switch. The delay performance under uniform traffic and the hot-spot throughput of DRRM is better than that of iSLIP, while the throughput of iSLIP under some nonuniform traffic scenarios is slightly higher than that of DRRM. Since throughput drops below 100%, under nonuniform traffic, we also examine some variations of the DRRM matching scheme for nonuniform traffic.
8036895
The case for multipath multimedia transport over wireless ad hoc networks
Real-time multimedia transport has stringent bandwidth, delay, and loss requirements. Supporting this application in current wireless ad hoc networks is a challenge. Such networks are characterized with frequent link failures, as well as congestion. Consequently, data packets are dropped when a link fails or congestion occurs, resulting in low received quality. In addition, a realtime multimedia service may be unavailable when a particular server is unreachable. In this article, we make the case for using multipath transport for realtime multimedia services in wireless ad hoc networks, which provides a unified solution to the above problems. We review existing work on multipath multimedia transport, and discuss the advantages, as well as related issues, of using multipath transport for realtime multimedia transport.
8996068
A mobile sensor network using autonomously controlled animals
Recent research has demonstrated that it is possible to use wireless communication to deliver brain stimulation to guide the movements of rats through a variety of terrains by stimulating multiple brain regions to produce stimulus cues for various commanded movements. The rats can be controlled not only while in direct line of sight of a human controller, but also by teleoperation, using signals transmitted from a wireless video camera mounted on the animal's backpack. Remotely guided rats or other animals are ideal for search and rescue operations because they are highly adept at negotiating difficult 3D terrain, in both light and dark. The animals autonomously choose their own methods for traversing particular obstacles. Primarily for these reasons, they can be more effective than mechanical robots in search and rescue applications. They can also be trained to detect and home in on specific sensory targets, allowing them to be used as biosensors. To meet these challenges, a cluster of interrelated research studies, including network topology design, routing algorithms, media access control techniques, radio resource management, radio propagation modeling, and mobility modeling are comprised. In this paper, the authors have designed and implemented the hardware of backpacks and set up a simple wireless ad hoc network by using static routing.
8401209
Optimal Traffic-Oblivious Energy-Aware Routing for Multihop Wireless Networks
Energy efficiency is an important issue in multihop wireless networks with energy concerns. Usually it is achieved with accurate knowledge of the traffic pattern and/or the current network information such as the remaining energy level. We investigate the problem of designing a routing scheme to minimize the maximum energy utilization of a multihop wireless network with weak assumption of the traffic pattern and without ongoing collection of network information. We develop polynomial size LP models to design such a routing scheme. We discuss generalizations of the LP models to various radio transmission models. In an interference-limited scenario, we show how to guarantee schedulability of the oblivious routing. We present an extension to consider lossy links. We also discuss implementation issues. The LP models achieve performance close to what an oracle can achieve in the performance study. The results for multihop wireless networks with a single sink are especially good. We make a first stride in designing a traffic-oblivious energy-aware routing framework in multihop wireless networks.
3968249
Topiary: a tool for prototyping location-enhanced applications
Location-enhanced applications use the location of people, places, and things to augment or streamline interaction. Location-enhanced applications are just starting to emerge in several different domains, and many people believe that this type of application will experience tremendous growth in the near future. However, it currently requires a high level of technical expertise to build location-enhanced applications, making it hard to iterate on designs. To address this problem we introduce Topiary, a tool for rapidly prototyping location-enhanced applications. Topiary lets designers create a map that models the location of people, places, and things; use this active map to demonstrate scenarios depicting location contexts; use these scenarios in creating storyboards that describe interaction sequences; and then run these storyboards on mobile devices, with a wizard updating the location of people and things on a separate device. We performed an informal evaluation with seven researchers and interface designers and found that they reacted positively to the concept.
34644814
The Independence Number of Graphs with a Forbidden Cycle and Ramsey Numbers
Let k ≥ 5 be a fixed integer and let m = ⌊(k − 1)/2⌋. It is shown that the independence number of a Ck-free graph is at least c1[∑ d(v)1/(m − 1)](m − 1)/m and that, for odd k, the Ramsey number r(Ck, Kn) is at most c2(nm + 1/log n)1/m, where c1 = c1(m) > 0 and c2 = c2(m) > 0.
1095698
DaNaLIX: a domain-adaptive natural language interface for querying XML
We present DaNaLIX, a prototype domain-adaptive natural language interface for querying XML. Our system is an extension of NaLIX, a generic natural language interface for querying XML. While retaining the portability of a purely generic system like NaLIX, DaNaLIX can exploit domain knowledge, whenever available, to its advantage for query translation. More importantly, in DaNaLIX such domain knowledge does not have to be pre-defined; instead it can be automatically obtained from the interactions between a user and the system. In this demonstration, we describe the overall architecture of DaNaLIX. We also demonstrate how a generic system like DaNaLIX can take advantage of domain knowledge to improve its usability and query translation accuracy. In addition, we show DaNaLIX still possesses the portability of a generic system by using data collections from three different domains. Finally, we present how domain knowledge can be obtained through user interactions in an automatic fashion.
2685399
EaseDB: a cache-oblivious in-memory query processor
We propose to demonstrate EaseDB, the first cache-oblivious queryprocessor for in-memory relational query processing. The cache-oblivious notion from the theory community refers to the property that no parameters in an algorithm or a data structure need to be tuned for a specific memory hierarchy for optimality. As a result, EaseDB automatically optimizes the cache performance as well as the overall performance of query processing on any memory hierarchy. We have developed a visualization interface to show the detailed performance of EaseDB in comparison with its cache-conscious counterpart, with both the parameters in the cache-conscious algorithms and the hardware platforms varied.