Browsing by Author "Avancha, Sasikanth"
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ItemAn Approach to Dynamic Service Management in Pervasive Computing(2002-10-09) Kagal, Lalana; Avancha, Sasikanth; Korolev, Vladimir; Joshi, Anupam; Finin, TimIn the near future, we will see dramatic changes in computing and networking hardware. A large number of devices (e.g., phones, PDAs, even small household appliances) will become computationally enabled. Micro/nano sensors will be widely embedded in most engineered artifacts, from the clothes we wear to the roads we drive on. All of these devices will be (wirelessly) networked using Bluetooth, IEEE 802.15 or IEEE 802.11 for short range connectivity creating pervasive environments. In this age, where a large number of wirelessly networked appliances and devices are becoming commonplace, there is a necessity for providing a standard interface to them that is easily accessible by any user. This paper outlines the design of Centaurus, an infrastructure for presenting services to heterogeneous mobile clients in a physical space via some short range wireless links. The infrastructure is communication medium independent; we have implemented the system over Bluetooth, CDPD and Infrared, three well-known wireless technologies. All the components in our model use a language based on Extensible Markup Language (XML) for communication, giving the system a uniform and easily adaptable interface. Centaurus defines a uniform infrastructure for heterogeneous services, both hardware and software, to be made available to diverse mobile users within a confined space. ItemDesign and Evaluation of a Common Access Point for Bluetooth, 802.11 and Wired LANs(2002-06-24) Bethala, Bhagyalaxmi; Joshi, Anupam; Phatak, Dhananjay; Avancha, Sasikanth; Goff, TomDevices using wireless technologies like Bluetooth and 802.11b will be ubiquitous in the near future. The technologies supporting these devices will need to co-exist in order to support smooth exchange of information. We envision the existence of an Access Point (AP) , that can sport all these wireless technologies and bridge wireless networks with wired networks. We present the design and preliminary performance evaluation of two types of APs - a Bluetooth Access Point (BAP) and a Common Access Point (CAP) for Bluetooth, WLAN and Ethernet networks. ItemDReggie: Semantic Service Discovery for M-Commerce Applications(2001-10-12) Chakraborty, Dipanjan; Perich, Filip; Avancha, Sasikanth; Joshi, AnupamThe emergence of mobile devices and wireless networks has created a new path in the field of e-commerce: “mcommerce”. Significant research is needed, in the field of service discovery, to support m-commerce applications. Various new applications, that would use services available to a mobile device from both the fixed network backbone and peer mobile devices in its proximity, are being developed. M-commerce applications have the challenging task of discovering services in a dynamically changing environment. The DARPA Agent Markup Language (DAML) is an important tool in the process of developing the Semantic Web. In this paper, we present a dynamic service discovery infrastructure that uses DAML to describe services and a Prolog reasoning engine to perform matching using the semantic content of service descriptions. We believe that the architecture we have designed is a necessary component of any m-commerce infrastructure. ItemEnhancing the Bluetooth Service Discovery Protocol(2001-08-01) Avancha, Sasikanth; Joshi, Anupam; Finin, TimothyBluetooth Service Discovery Protocol (SDP) enables a client application on a device to discover information about services on other Bluetooth devices. Every service is represented by a profile, identified by a 128-bit Universally Unique Identifier (UUID). A match occurs on a peer device if and only if at least one UUID specified by the client is contained in one or more of its service records. We believe that the advantages of UUID-based matching to support service discovery are restricted to ad-hoc Bluetooth networks consisting of resource constrained devices. The more common case for applications using Bluetooth networks, is the existence of one or more resource rich devices (e.g., the Compaq iPAQ) in the network. This calls for a matching mechanism that uses semantic information associated with services and attributes to decide the success or failure of a query. We present an enhanced version of Bluetooth SDP that supports semantic matching and provides service registration. We evaluate the performance of this enhanced version of SDP and compare it with regular SDP. We show that enhanced SDP performs comparably to regular SDP in terms of Round Trip Time and matching time. ItemInformation agents for mobile and embedded devices(World Scientific Publishing Co Pte Ltd, 2002-09-01) Finin, Tim; Joshi, Anupam; Kagal, Lalana; Ratsimor, Olga; Avancha, SasikanthThe pervasive computing environments of the near future will involve the interactions, coordination and cooperation of numerous, casually accessible, and often invisible computing devices. These devices, whether carried on our person or embedded in our homes, businesses and classrooms, will connect via wireless and wired links to one another and to the global networking infrastructure. The result will be a networking milieu with a new level of openness. The localized and dynamic nature of their interactions raises many new issues that draw on and challenge the disciplines of agents, distributed systems, and security. This paper describes recent work by the UMBC Ebiquity research group which addresses some of these issues. ItemIntelligent Agents for Mobile and Embedded Devices(World Scientific Publishing Co Pte Ltd, 2002-12-01) Finin, Tim; Joshi, Anupam; Kagal, Lalana; Ratsimor, Olga Vladi; Avancha, Sasikanth; Korolev, Vladimir; Chen, Harry; Perich, Filip; Cost, R. ScottThe pervasive computing environments of the near future will involve the interactions, coordination and cooperation of numerous, casually accessible, and often invisible computing devices. These devices, whether carried on our person or embedded in our homes, businesses and classrooms, will connect via wireless and wired links to one another and to the global networking infrastructure. The result will be a networking milieu with a new level of openness. The localized and dynamic nature of their interactions raises many new issues that draw on and challenge the disciplines of agents, distributed systems, and security. This paper describes recent work by the UMBC Ebiquity research group which addresses some of these issues. ItemIssues in Data Management for Pervasive Environments(2002-01-12) Avancha, Sasikanth; Chakraborty, Dipanjan; Chen, Harry; Kagal, Lalana; Perich, Filip; Joshi, AnupamA new vista is open for research in the area of data management in pervasive environments where mobile devices gather and exchange information from other devices based on their current context. Each device is both a data source and a data consumer pursuing its individual and collective tasks. Our research group is investigating various ideas aimed at realizing pervasive computing systems based on the cooperation of autonomous, dynamic and adaptive components located in vicinity of one another. These systems will enable devices to discover information, compose it, and analyze it for consistency, all in a secure and trusted manner. ItemOntology-driven Adaptive Sensor Networks(IEEE, 2004-08-22) Avancha, Sasikanth; Patel, Chintan; Joshi, AnupamA wireless sensor network deployed in an area of interest affected by variations in environmental conditions associated with that area. It must adapt to these variations in order to continue functioning as desired by the user. We present a novel, two-phase solution to the wireless sensor network adaptivity problem. In the first phase, nodes in the network, organized as clusters, execute an efficient algorithm to dynamically calibrate sensed data. Each node provides its current energy level and the state of each on-board sensor to a cluster-head. In the second phase, each cluster-head executes an efficient, ontology-driven algorithm to determine the future state of the network under existing conditions, based on information received from each sensor node. We describe an example application scenario to show how our two-phase solution can be employed to enable a real-world wireless sensor network to adapt itself to variations in environmental conditions. ItemQuery Routing and Processing in Mobile Ad-Hoc Environments(2001-11-12) Perich, Filip; Avancha, Sasikanth; Joshi, Anupam; Yesha, Yelena; Joshi, KarunaIn existing mobile information access systems, mobile devices are typically viewed as consumers of information, with information providers resident on the wired network. With the advent of short-range ad-hoc connectivity based on Bluetooth like systems, an alternative scenario arises where mobile devices gather and exchange information from not just wired sources, but also their environment and one another. Each device is both a source and a consumer of information/data. In this paper we describe new challenges that this scenario presents to the distributed database framework, and present the design of a framework for serendipitous querying and query response in an ad-hoc mobile environment. We also describe an implementation of this system on mobile devices connected over Bluetooth networks, and present experimental results. ItemSecurity for Wireless Sensor Networks(Springer Nature Switzerland AG., 2004-01-01) Avancha, Sasikanth; Undercoffer, Jeffrey; Joshi, Anupam; Pinkston, JohnThis chapter identifies the vulnerabilities associated with the operational paradigms currently employed by Wireless Sensor Networks. A survey of current WSN security research is presented. The security issues of Mobile Ad-Hoc Networks and infrastructure supported wireless networks are briefly compared and contrasted to the security concerns of Wireless Sensor Networks. A framework for implementing security in WSNs, which identifies the security measures necessary to mitigate the identified vulnerabilities is defined. ItemTransport Protocols in Wireless Networks(IEEE, 2001-10-15) Avancha, Sasikanth; Korolev, Vladimir; Joshi, Anupam; Finin, TimIt is well-known that TCP performs poorly in a wireless environment. This paper presents an empirical performance analysis of TCP on Cellular Digital Packet Data (CDPD) and Bluetooth. This analysis brings out the weaknesses of TCP in realistic conditions. We also present CentaurusComm, a message based transport protocol designed to perform well in low bandwidth networks and resource poor devices. In particular, CentaurusComm is optimized to handle data exchanges consisting of short message sizes. The application used to perform all the experiments is typical of common applications that would use these protocols and network technologies. Typical mobile devices used in the experiments included Palm Pilots. We show that TCP performance on CDPD is very poor because of its low bandwidth and high latency. CentaurusComm outperforms TCP on CDPD.We show that on Bluetooth, which has higher bandwidth and lower latency than CDPD, both protocols perform comparably. ItemUsing Ontologies in the Semantic Web: A Survey(2005-07-20) Ding, Li; Kolari, Pranam; Ding, Zhongli; Avancha, Sasikanth; Joshi, AnupamThe Semantic Web is well recognized as an effective infrastructure to enhance visibility of knowledge on the Web. The core of the Semantic Web is ontology, which is used to explicitly represent our conceptualizations. Ontology engineering in the Semantic Web is primarily supported by languages such as RDF, RDFS and OWL. This chapter discusses the requirements of ontologies in the context of the Web, compares the above three languages with existing knowledge representation formalisms, and surveys tools for managing and applying ontologies. Advantages of using ontologies in both knowledge-base-style and database-style applications are demonstrated using three real world applications.