In this paper, we elaborate a set of scenarios and experiments for evaluating the impact of the physical environment on a Wireless Sensor Network (WSN). More specifically, a WSN application is implemented for collecti...
详细信息
In Wireless Sensor Network (WSN) researches, WSN routing algorithm is one of the hot issues. This article focuses on GPSR (Greedy Perimeter Stateless Routing) and uses the NS2 (Network Simulator-2) to simulate both GP...
详细信息
Generalization of web sessions is an effective approach used to overcome two major challenges in web usage mining, namely quality and scalability. Given a concept hierarchy, such as a website, generalization replaces ...
详细信息
ISBN:
(纸本)9781605588087
Generalization of web sessions is an effective approach used to overcome two major challenges in web usage mining, namely quality and scalability. Given a concept hierarchy, such as a website, generalization replaces actual page-clicks with their general concepts, i.e., nodes at higher levels. Presently known methods do this by choosing a level in the hierarchy, below which all the nodes are generalized to nodes at this level. The problem with this is that significant items may be coalesced, and insignificant ones may be retained. We present a usage driven generalization algorithm, which coalesces less significant pages into more general ones, independent of their level in the hierarchy. Based on actual usage set of sessions, item significance is estimated approximately but fast, using a small stratified sample of the large dataset. While providing scalability, the proposed generalization technique results in improved efficiency and quality of the discovered usage model, demonstrated through numerous experiments in our work. Copyright 2009 ACM.
Rank order correlation has been used extensively when the data is non-parametric or when the relationship between two variables is nonlinear and monotonic. In such cases, linear correlation measures, such as the produ...
详细信息
ISBN:
(纸本)9781595939913
Rank order correlation has been used extensively when the data is non-parametric or when the relationship between two variables is nonlinear and monotonic. In such cases, linear correlation measures, such as the product-moment coefficient, are inadequate and fail to detect correlative relations. We present a polyhedral indexing technique for rank order correlation queries for time series data. We use an interesting geometry interpretation of rank order correlation which lends itself to indexing by spatial indexes such as R-trees. Our experimental results indicate one to two orders of magnitudes improvement over sequential scan - the only alternative solution.
Many studies undertaken in the field of education have revealed that m-learning is emerging more and more as an effective learning method with the use of smartphones. Always turned on and easily transported, smartphon...
详细信息
ISBN:
(纸本)9789899887572
Many studies undertaken in the field of education have revealed that m-learning is emerging more and more as an effective learning method with the use of smartphones. Always turned on and easily transported, smartphones can be used anywhere, at any given time and in any context. Considering the potential of m-learning, we seek to understand this novelty as a support in the learning process, especially in computerscience education. To reach this end, we asked a group of students their opinion in the form of a survey, in order to know the most beneficial aspects of a mobile application in education. The outcome of this survey helped us to develop a mobile application from which students could access course news, work timing, frequently asked questions and results. After using this application, a second survey highlights students' interest. We thus show that, especially for courses such as programming courses, mlearning plays a full role as it offers accessibility to valuable information which comes in a continuous flow to support the learning process and as it offers an environment where interaction with the learning tool can be adapted and adjusted to the learner's style and needs.
Numerous logic frameworks have been proposed for modeling uncertainty and reasoning with such data. While different in syntax, the approaches of these frameworks have been classified into "annotation based" ...
详细信息
ISBN:
(纸本)9781577354192
Numerous logic frameworks have been proposed for modeling uncertainty and reasoning with such data. While different in syntax, the approaches of these frameworks have been classified into "annotation based" (AB) and "implication based" (IB). In this paper, we present a unified framework which allows evaluating programs in either approach. It extends existing query processing techniques to handle certainty constraints and uses heuristics to further improve the performance. Our experiments indicate that the proposed techniques yield useful tools for uncertainty reasoning.
Rewriting of conjunctive queries using views has many applications in database and data *** investigate ways to improve performance of rewriting and propose a new algorithm which has two phases. In the first phase, si...
详细信息
Rewriting of conjunctive queries using views has many applications in database and data *** investigate ways to improve performance of rewriting and propose a new algorithm which has two phases. In the first phase, similar to Minicon, we find mapping information, which we call coverages, from subgoals in the query to subgoals in view, and assign positive integers (n) as identifiers to these coverages, where n is the number of subgoals in the query. In the rewriting phase, based on the available identifiers and partitions of the set -1, ., 2n-1}, we define patterns and use them to encode the buckets and the coverages they contain. This breaks the cartesian product of a set of large buckets into several cartesian products on sets of smaller buckets. In other words, an expensive cartesian product could be broken into a maximum of B(n) small cartesian products, where B is the Bell number. Our numerous experiments using different query types and sizes indicate significant time and space improvement for computing the cartesian products of the buckets and generating the output.
In large software organizations with a product line development approach, system test planning and scope selection is a complex tasks for which tool support is needed. Due to repeated testing: across different testing...
详细信息
This paper describes an approach to improving the robustness of an agent system by augmenting its failure-handling capabilities. The approach is based on the concept of semantic compensation: "cleaning up" f...
详细信息
In this paper, we propose an experiment design and implementation for distance evaluation in wireless sensor networks (WSN). More specifically, a WSN application is implemented for collecting received signal strength ...
详细信息
暂无评论