Efficient SatelliteBased Sensor Networks for Information Retrieval

... BISIO AND MARCHESE: EFFICIENT SATELLITE-BASED SENSOR NETWORKS FOR INFORMATION RETRIEVAL 465 Fig Example of EMS for weather prediction The assumption of this paper is that all sensors directly communicate ... four performance macro areas It is the first step towards the formal definition of objective performance metrics 1) Information Loss: The importance of the Information Los...

Ngày tải lên: 14/04/2015, 13:52

... relations; and foregrounding devices (Figure 4) 148 Belkin, N.J., Brooks, H.M., and Oddy, R.N 1979 Representation and classification of knowledge and information for use in interactive information ... constraints typical of DR systems The modi~,cations are designed to recognize such aspects of discourse structure as establishment of topic; "setting of context; summarizing; con...

Ngày tải lên: 21/02/2014, 20:20

... behind both of these hypotheses is that, just as individual words can be content- rich or content- poor, the same can hold for blocks of parts of speech According to our first hypothesis, POS blocks ... hypothesis, POS blocks can be categorized as content- rich or content- poor, on the basis of the part of speech class membership of their individual componen...

Ngày tải lên: 08/03/2014, 02:21

... using extracted subcompounds for indexing Phrase-Based Indexing The selection of appropriate indexing terms is critical to the improvement of both precision and recall in an IR task The ideal indexing ... potentially valuable in indexing In practice, of course, the indexing term space has to be limited, so it is necessary to select a subset of phrases for indexing Short phrases (oft...

Ngày tải lên: 17/03/2014, 09:20

... such as a, which stands for alpha in chemistry and is relevant in biomedical expressions such as vitamin a 4.2 Argumentative categorizer The argumentative classifier ranks and categorizes abstract ... Biology Articles as a Basis for Information Extraction International Journal of Medical Informatics, to appear C Orasan 2001 Patterns in Scientific Abstracts In Proceedings of Corpus Li...

Ngày tải lên: 23/03/2014, 18:20

... Statistical phrases for vector-space information retrieval In Proceedings of SIGIR ’99, pages 309–310 C J van Rijsbergen 1977 A theoretical basis for the use of co-occurrence data in information retrieval ... both words and phrases, one would definitely raise a fundamental question on how much weight should be given to the phrase information compared to the word information In...

Ngày tải lên: 30/03/2014, 23:20

... subject Therefore word co-occurrence information can be used to identify semantic relationships between words (Schutze and Pederson, 1997; Schutze and Pederson, 1994) We use mutual information as ... tool for computing similarity between words Mutual information compares the probability of the co-occurence of words a and b with the independent probabilities of occurrence of...

Ngày tải lên: 31/03/2014, 21:20

... Chapter Background Knowledge 2.1 Textual Information Extraction Techniques for Scanned Document Images Textual information extraction techniques for scanned images are divided into three categories: ... Spotting The ultimate goal of extracting textual information is for information retrieval The output of the extraction are passed to downstream retrieval app...

Ngày tải lên: 12/09/2015, 11:24

... Opportunistic carrier sensing for n∗ = Figure 4: Opportunistic carrier sensing sensing period, sensors transmit, with backoff delay determined by f (γ), a beacon signal with short duration A sensor ... 300 350 400 450 500 r Opportunistic carrier sensing with/without delay Opportunistic carrier sensing with delay n-TDMA Figure 7: Performance of opportunistic carri...

Ngày tải lên: 23/06/2014, 00:20

... throughput The effect of MAC for information retrieval on information processing is analyzed in [7, 8] for in nite and finite sensor density networks, respectively, where the performance of the centralized ... bandwidth required for sensors reporting their locations is prohibitively Here, m − points are sought instead of m points in the linear field case MAC for Optima...

Ngày tải lên: 23/06/2014, 00:20

... ANALYSIS, DESIGN AND OPTIMIZATION OF ENERGY EFFICIENT PROTOCOLS FOR WIRELESS SENSOR NETWORKS HOANG DUC CHINH (B.Eng., Hanoi University of Technology, Vietnam) A THESIS SUBMITTED FOR THE ... 21 1.3.4 Energy Efficient Routing and Optimization Methods in Wireless Sensor Networks 24 2.1 Introduction 24 2.2 Routing Protocols for Wireless Sensor Netwo...

Ngày tải lên: 10/09/2015, 09:04

... this dissertation, we design and implement efficient large data dissemination and collection protocols for wireless sensor networks, which outperform state-of-the-art protocols by a large margin ... Efficient Data Dissemination and Collection Protocols for Wireless Sensor Networks Manjunath Doddavenkatappa A THESIS SUBMITTED FOR THE DEGREE OF PhD IN COMP...

Ngày tải lên: 10/09/2015, 09:10

... wireless networks such as Moible Ad Hoc Networks (MANET) and wireless sensor networks Routing protocols for MANET have been designed to handle fast topology changes On the other hand, in wireless sensor ... attempts to solve the routing problem due to the dynamics of wireless links and therefore focus on designing robust and energy efficient routing protocols...

Ngày tải lên: 11/09/2015, 16:06

... mainly focus on the design of energy efficient protocols for WSNs in the form of wakeup scheduling of the sensor nodes We propose two energy conserving protocols for different applications, one ... WSN is designed for, it is necessary to make the protocols as energy- efficient as possible The reason is simply because the source of energy for typical sensors are limit...

Ngày tải lên: 05/10/2015, 21:23

... randomized tdma scheduling for wireless ad-hoc networks In MobiHoc, 2006 [17] M Sha, G Xing, G Zhou, and S Liu C-mac: Model-driven concurrent medium access control for wireless sensor networks Technical ... preamble mac protocol for duty-cycled wireless sensor networks In SenSys, 2006 [4] O Chipara, C Lu, and J Stankovic Dynamic conflict-free query scheduling for...

Ngày tải lên: 01/09/2013, 15:23