9322495
SOUPA: standard ontology for ubiquitous and pervasive applications
We describe a shared ontology called SOUPA - standard ontology for ubiquitous and pervasive applications. SOUPA is designed to model and support pervasive computing applications. This ontology is expressed using the Web ontology language OWL and includes modular component vocabularies to represent intelligent agents with associated beliefs, desires, and intentions, time, space, events, user profiles, actions, and policies for security and privacy. We discuss how SOUPA can be extended and used to support the applications of CoBrA, a broker-centric agent architecture for building smart meeting rooms, and MoGATU, a peer-to-peer data management for pervasive environments.
5485929
ITTALKS: A Case Study in the Semantic Web and DAML
Effective use of the vast quantity of information now available on the web will require the use of "Semantic Web" markup languages such as the DARPA Agent Markup Language (DAML). Such languages will enable the automated gathering and processing of much information that is currently available but insufficiently utilized. Effectively, such languages will facilitate the integration of multi-agent systems with the existing information infrastructure. As part of our exploration of Semantic Web technology, and DAML in particular, we have constructed ITTALKS, a web-based system for automatic and intelligent notification of information technology talks. In this paper, we describe the ITTALKS system, and discuss the numerous ways in which the use of Semantic Web concepts and DAML extend its ability to provide an intelligent online service to both the human community and the agents assisting them.
16963632
Agents Making Sense of the Semantic Web
Effective use of the vast quantity of available information and services on the Internet will require multi-agent systems to be tightly integrated with existing web infrastructure. This however will be impossible unless the information on the web is presented in a semantic language, such as the DARPA Agent Markup Language (DAML), which is one aim of the “Semantic Web”. As part of our exploration of Semantic Web technology, and DAML in particular, we have constructed ITTALKS, a web-based system for automatic and intelligent notification of information technology talks. In this paper, we describe the ITTALKS system, and discuss the numerous ways in which the use of Semantic Web concepts and DAML extend its ability to provide an intelligent online service to both the human community and, more interestingly, the agents assisting them.
2898024
Using OWL in a Pervasive Computing Broker
Computing is moving toward a pervasive context-aware environment in which agents with limited resources will require external support to help them become context-aware. In this paper, we describe an agent based architecture called Context Broker Architecture (CoBrA) to help these agents to acquire, reason about and share context knowledge. A key component in our architecture is an explicit context ontology defined using the Web Ontology Language (OWL). This ontology models the basic concepts of people, agents, places, and presentation events. We also describe a use case scenario and prototype design of CoBrA in an intelligent meeting room environment.
7036833
Dynamic Service Discovery for Mobile Computing: Intelligent Agents Meet Jini in the Aether
The emergence of ad-hoc pervasive connectivity for devices based on Bluetooth-like systems provides a new way to create applications for mobile systems. We seek to realize ubiquitous computing systems based on the cooperation of autonomous, dynamic and adaptive components (hardware as well as software) which are located in vicinity of one another. In this paper we present this vision. We also describe a prototype system we have developed that implements parts of this vision – in particular a system that combines agent oriented and service oriented approaches and provides dynamic service discovery. We point out why existing systems such as Jini are not suited for this task, and how our system improves on them.
14330906
Creating Context-Aware Software Agents
Sharing ontologies, sensing context and reasoning are crucial to the realization of context-aware software agents. This document de- scribes our efforts in using the Resource Description Framework (RDF) and Prolog Forward Chaining (Pfc) system to provide support for ontology sharing and reasoning in the CoolAgent Recommendation System (CoolAgent RS), a context-aware multi-agent system. We also describes the implementation of the CoolAgent RS document and cuisine recommendation services that provide tailored services by exploiting user's context.
196155386
Compound brushing
This paper proposes a conceptual model called compound brushing for modeling the brushing techniques used in dynamic data visualization. In this approach brushing techniques are modeled as higraphs with five types of basic entities: data, selection, device, renderer, and transformation. Using this model, a flexible visual programming tool is designed not only to configure/control various common types of brushing techniques currently used in dynamic data visualization, but also to investigate new brushing techniques.
13538048
Error Free Self-assembly Using Error Prone Tiles
DNA self-assembly is emerging as a key paradigm for nano-technology, nano-computation, and several related disciplines. In nature, DNA self-assembly is often equipped with explicit mechanisms for both error prevention and error correction. For artificial self-assembly, these problems are even more important since we are interested in assembling large systems with great precision. 
 
We present an error-correction scheme, called snaked proof-reading, which can correct both growth and nucleation errors in a self-assembling system. This builds upon an earlier construction of Winfree and Bekbolatov [11], which could correct a limited class of growth errors. Like their construction, our system also replaces each tile in the system by a k × k block of tiles, and does not require changing the basic tile assembly model proposed by Rothemund and Winfree [8]. 
 
We perform a theoretical analysis of our system under fairly general assumptions: tiles can both attach and fall off depending on the thermodynamic rate parameters which also govern the error rate. We prove that with appropriate values of the block size, a seed row of n tiles can be extended into an n × n square of tiles without errors in expected time $\widetilde{O}(n)$, and further, this square remains stable for an expected time of $\widetilde{\Omega}(n)$. This is the first error-correction system for DNA self-assembly that has provably good assembly time (close to linear) and provable error-correction. The assembly time is thesame, up to logarithmic factors, as the time for an irreversible, error-free assembly. 
 
We also did a preliminary simulation study of our scheme. In simulations, our scheme performs much better (in terms of error-correction) than the earlier scheme of Winfree and Bekbolatov, and also much better than the unaltered tile system. 
 
Our basic construction (and analysis) applies to all rectilinear tile systems (where growth happens from south to north and west to east). These systems include the Sierpinski tile system, the square-completion tile system, and the block cellular automata for simulating Turing machines. It also applies to counters, a basic primitive in many self-assembly constructions and computations.
10838244
Streaming SMIL Presentations via a Multimedia Semantic Model
The Synchronized Multimedia Integration Language (SMIL) allows Web designers to design complicated and vivid multimedia presentations in a declarative manner. In this paper, an abstract semantic model called Multimedia Augmented Transition Network (MATN) is used to model the conceptual structure of SMIL, as well as the temporal relations and synchronization control. The advantages of using the MATN model are its simplicity and ease of modification (scalability). Users can easily generate their favorite multimedia presentations using MATNs and render them using the SMIL players. Since the SMIL specification is quite new to the Internet society, the functionality of the players is limited, i.e., they often acquire proprietary platforms or cannot deal with MPEG or RTP media objects. Another contribution of this paper is to propose a novel architecture based on Java JMF technology for tackling with such constraints.
1212877
The expressive rate of constraints
In reasoning tasks involving logical formulas, high expressiveness is desirable, although it often leads to high computational complexity. We study a simple measure of expressiveness: the number of formulas expressible by a language, up to semantic equivalence. In the context of constraints, we prove a dichotomy theorem on constraint languages regarding this measure.
1381399
A Context-Aware HTML/XML Document Transmission Process for Mobile Wireless Clients
Delivery and rendering of HTML/XML documents has been a core task in many contemporary networking applications. In mobile wireless networks, efficient handling of these types of documents is necessary due to the frequent disconnections, packet loss, and high bit error rate. One approach to address the challenge is the ability to process and reuse the partial data. Current application protocols like HTTP cannot support this approach due to the following constraints: TCP's in-order data uploading to the applications and tag matching. We propose a context-aware transmission process (CATP) to run on top of UDP. This protocol does not transmit HTML/XML files in-order. Instead, it reorganizes the files and transmit tags first before transporting their enclosed data. Conforming browsers receive the file structures and fill in with subsequent data packets in whatever sequence they arrive. As a result, lost and delayed packets do not hinder rendering of those that are logically behind but have already arrived at the client sides. Thus the retransmission of the lost frames can be concealed and overall user perceived performance improved. The user-perceivable performance is quantified in terms of silent time during which no activity is observed at the browser display. The protocol also facilitates partial content caching, amortizing network transmission overhead, and non-interactive applications of Web services. We validated this protocol through prototype implementation and compared the performance with TCP and in-order delivery UDP schemes. Our protocol provides better user-perceivable performance under various loss rates and document sizes.