In this paper, we propose a Web recommendation system based on a maximum entropy model. Under the maximum entropy principle, multiple sources of knowledge about users' navigational behavior in a Web site can be seamlessly combined to discover usage patterns and to automatically generate the most effective recommendations for new users with similar profiles. In this paper we integrate the knowledge from page-level clickstream statistics about users' past navigations with the aggregate usage patterns discovered through Web usage mining. Our experiment results show that our method can achieve better prediction accuracy when compared to standard recommendation approaches, while providing a better interpretation of Web users' diverse navigational behaviors.
Recently proposed key management systems (KMSs) provide limited functionality in highly partitioned mobile ad hoc networks. In this paper we present a framework for key management that provides redundancy and robustness for Security Association (SA) establishment between pairs of nodes in mobile ad hoc networks. Our KMS uses a modified hierarchical trust Public Key Infrastructure (PKI) model in which nodes can dynamically assume management roles. The system ensures high service availability for the network members through a number of schemes. A novel behavior grading mechanism provides security criteria for the network nodes and aids the management functions of the KMS to revoke or reissue certificates for nodes. This mechanism is based on the notion of trust, and more specifically on SAs among nodes in the entire network. In this paper we give an overview of the framework of the system and present a performance analysis of the system based on certificate issuance and acquisition. Finally, we compare our KMS with threshold cryptography schemes.
A vast amount of data is available on the World Wide Web. Many companies have started to mine this data to augment datasets used in production. This paper presents an industry study for one such text data mining. The study and analysis of the extracted data from the World Wide Web could be used to help improve products and services. A prototype has been completed and benched marked in the laboratory.
Outdoor location systems based on wireless access point (WAP) signal strength must either know the exact location of the WAPs in order to use a triangulation algorithm, or must construct a radio-map of the signal strengths. While the radio-map technique increases accuracy and can accommodate a wireless network that is not owned by any one entity, conventional methods for constructing a radio-map are labor-intensive and impractical in such environments. We introduce a toolkit for automatically constructing outdoor radio-maps. Our toolkit can easily be carried by delivery personnel and security guards during their normal work duties to obtain signal readings. The scattered data readings are then fed into an interpolation algorithm to construct a more complete grid that can be used as the radio-map.
We describe our experience applying tabular mathematical approaches to software specifications. Our purpose is to show alternative approaches to writing tabular specifications and to help practitioners who want to apply such methods by allowing them to pick the best one for their problem. The object for the case study is software used by Dell Products for testing the functionality of the keyboards on notebook computers. Starting from informal documents, we developed a variety of tabular representations of finite state machine specifications and tabular trace specifications. We found that the discipline required by these methods raised issues that had never been considered and resulted in documents that were both more complete and much clearer. The various tabular representations are compared from a user's point of view, i.e., clarity, consistency, unambiguity, completeness, suitability, etc.
