8242993
Designing Web-Based Systems in Social Context: A Goal and Scenario Based Approach
In order to design a better web-based system, a designer would like to have notations to visualize how design experts’ know-how can be applied according to one’s specific social and technology situation. We propose the combined use of a goal-oriented language GRL and a scenarios-oriented notation UCM for representing design knowledge of web-based systems and information systems in general. Goals are used to depict business objectives, functional and non-functional system requirements. Tasks are used in the exploration of alternative technologies and their operationalizations into system constructs. Actors are used to do role-based analysis on social relationships. Scenarios are used to describe elaborated business processes or workflow. The approach is illustrated with an example of designing a web-based training system.
2115447
Security and privacy requirements analysis within a social setting
Security issues for software systems ultimately concern relationships among social actors stakeholders, system users, potential attackers - and the software acting on their behalf. We propose a methodological framework for dealing with security and privacy requirements based on i*, an agent-oriented requirements modeling language. The framework supports a set of analysis techniques. In particular, attacker analysis helps identify potential system abusers and their malicious intents. Dependency vulnerability analysis helps detect vulnerabilities in terms of organizational relationships among stakeholders. Countermeasure analysis supports the dynamic decision-making process of defensive system players in addressing vulnerabilities and threats. Finally, access control analysis bridges the gap between security requirement models and security implementation models. The framework is illustrated with an example involving security and privacy concerns in the design of agent-based health information systems. In addition, we discuss model evaluation techniques, including qualitative goal model analysis and property verification techniques based on model checking.
10661094
Designing information systems in social context: a goal and scenario modelling approach
In order to design a better information system, a designer would like to have notations to visualize how design experts' know-how can be applied according to one's specific social and technology situation. We propose the combined use of a goal-oriented requirements language (GRL) and a scenario-oriented notation Use Case Maps (UCM) for representing design knowledge of information systems. Goal-oriented modelling is used throughout the requirements and design process. In GRL, goals are used to depict business objectives and system requirements, both functional and non-functional. Tasks are used to represent different ways for achieving goals. Means-ends reasoning is used to explore alternative solutions and their operationalizations into implementable system constructs. Social context is modelled in terms of dependency relationships among agents and roles. Scenarios expressed in UCM are used to describe elaborated business processes or workflow. The complementary use of goal-oriented modelling with GRL and scenario modelling with UCM is illustrated with an example of designing a web-based training system.
1197804
POESIA: An ontological workflow approach for composing Web services in agriculture
Abstract.This paper describes the POESIA approach to systematic composition of Web services. This pragmatic approach is strongly centered in the use of domain-specific multidimensional ontologies. Inspired by applications needs and founded on ontologies, workflows, and activity models, POESIA provides well-defined operations (aggregation, specialization, and instantiation) to support the composition of Web services. POESIA complements current proposals for Web services definition and composition by providing a higher degree of abstraction with verifiable consistency properties. We illustrate the POESIA approach using a concrete application scenario in agroenvironmental planning.
17663309
Impact of network resource constraints on the performance of wireless sensor relay networks
This work studies the impact of the network resource constraints on the performance of wireless sensor multi-hop relay networks. A differential space-time coding and the cooperative relay scheme for cross layer design is introduced in multi-hop wireless sensor networks. To analyze the network performance of such a system, the relay system from source to destination is simplified as a virtual bit pipe line, and a Markov chain model as well as an M/G/1 queueing system are used. The closed form expression for throughput and delay are derived in the infinite buffer case. A truncated Markov chain model and an M/G/1/K queueing system are used to model the finite buffer situation. Moreover, the system drop probability and the go through delay are studied based on the models.
11093943
Distributed query sampling: a quality-conscious approach
We present an adaptive distributed query-sampling framework that is quality-conscious for extracting high-quality text database samples. The framework divides the query-based sampling process into an initial seed sampling phase and a quality-aware iterative sampling phase. In the second phase the sampling process is dynamically scheduled based on estimated database size and quality parameters derived during the previous sampling process. The unique characteristic of our adaptive query-based sampling framework is its self-learning and self-configuring ability based on the overall quality of all text databases under consideration. We introduce three quality-conscious sampling schemes for estimating database quality, and our initial results show that the proposed framework supports higher-quality document sampling than existing approaches.
1602249
Mobile Web and Location-Based Services
The Web today, powered by Web server, application server technology, and Web services, is the lingua franca of the bulk of contents out on the Internet. As computing and communications options become ubiquitous, this Internet access capability is being embedded in billions of wireless devices such as PDAs, cellular phones, and computers embedded in vehicles. The Mobile Web is extending the Web through mobile information access, with the promise of greater information access opportunity, richer and device-spanning Web experiences, due to continuous availability and location awareness. In addition, advances in positioning technologies, mobile hardware, and the growing popularity and availability of mobile communications have made many devices location-aware. Location-based information management has become an important problem in mobile computing systems. Furthermore, the computational capabilities in mobile devices continue to rise, making mobile devices increasingly accessible. However, much research efforts to date have been devoted to location management in centralized location monitoring systems. Very few have studied the distributed approach to real-time location management. We argue that for mobile applications that need to manage a large and growing number of mobile objects, the centralized approaches do not scale well in terms of server load and network bandwidth, and are vulnerable to single point of failure. In this keynote, I will describe the distributed location service architecture, and discuss some important opportunities and challenges of mobile location based services (LBSs) in future computing environments. I will first review the research and development of LBSs in the past decade, focusing on system scalability, robustness, and performance measurements. Then I will discuss some important challenges for wide deployment of distributed location-based services in mission-critical applications and future computing environments. Not surprisingly, the mobile web and the location-aware computing will drive the merger of wireless and wired Internet world, creating a much larger industry than today’s predominantly wired Internet industry.
8443356
Efficient web change monitoring with page digest
The Internet and the World Wide Web have enabled a publishing explosion of useful online information, which has produced the unfortunate side effect of information overload: it is increasingly difficult for individuals to keep abreast of fresh information. In this paper we describe an approach for building a system for efficiently monitoring changes to Web documents. This paper has three main contributions. First, we present a coherent framework that captures different characteristics of Web documents. The system uses the Page Digest encoding to provide a comprehensive monitoring system for content, structure, and other interesting properties of Web documents. Second, the Page Digest encoding enables improved performance for individual page monitors through mechanisms such as short-circuit evaluation, linear time algorithms for document and structure similarity, and data size reduction. Finally, we develop a collection of sentinel grouping techniques based on the Page Digest encoding to reduce redundant processing in large-scale monitoring systems by grouping similar monitoring requests together. We examine how effective these techniques are over a wide range of parameters and have seen an order of magnitude speed up over existing Web-based information monitoring systems.