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.
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.
38207892
On the Relations Between Arboricity and Independent Number Or Covering Number
In this paper, the following results are obtained: a(G) + β(G) ⩽ p + 1, ⌈p2⌉ ⩽ a(G)β(G), ⌈p2⌉ ⩽ a′(G) + gb′(G) ⩽ pa′(G) + α′(G) ⩽ 2⌈p2⌉ (δ ⩽ 1) and all bounds are sharp, where p = ¦V(G)¦, ⌈x⌉ denotes the smallest integer greater than or equal to x, a(G) is the vertex arboricity, a′(G) is the edge arboricity, α′(G) is the edge covering number, β(G) is the vertex independent number, β′(G) is the edge independent number, and δ is the minimum degree of G.
5593987
Page Digest for large-scale Web services
We introduce Page Digest, a mechanism for efficient storage and processing of Web documents. The Page Digest design encourages a clean separation of the structural elements of Web documents from their content. Its encoding transformation produces many of the advantages of traditional string digest schemes yet remains invertible without introducing significant additional cost or complexity. Using the Page Digest encoding can provide at least an order of magnitude speedup when traversing a Web document as compared to using a standard document object model implementation. Our experiments show that change detection using Page Digest operates in linear time, offering 75% improvement in execution performance compared with existing systems. In addition, the Page Digest encoding can reduce the tag name redundancy found in Web documents, allowing 30% to 50% reduction in document size.
7311513
Polygonal Shape Blending with Topological Evolutions
This paper presents a new general approach to blend 2D shapes with different topologies. All possible topological evolutions are classified into three types by attaching three different topological cells. This formalism is resulted from Morse theory on the behavior of the 3D surface around a non-degenerate critical point. Also we incorporate degenerate topological evolutions into our framework which produce more attractive morphing effects. The user controls the morph by specifying the types of topological evolutions as well as the feature correspondences between the source and target shapes. Some techniques are also provided to control the vertex path during the morphing process. The amount of user input required to produce a morph is directly proportional to the amount of control the user wishes to impose on the process. The user may allow the system to automatically generate the morph as well. Our approaches are totally geometric based and are easy and fast enough in fully interactive time. Many experimental results show the applicability and flexibility of our approaches.
1693623
Hooking into Object-Oriented Application Frameworks
An object-oriented application framework provides a generic design within a given domain and a reusable implementation of that design. Frameworks have great potential for reuse, but that potential can only be achieved if the framework can be understood and used effectively by application developers. The complexity of the design and implementation of a framework can make understanding the framework difficult, and so good documentation and guidance to the framework user is needed. Several methods exist for documenting the design of the framework, but less work has been done on documenting the purpose of the framework and how it is intended to be used. In this paper, we introduce the concept of hooks as a means of documenting and providing guidance on the intended use of a framework. Each hook provides a concise solution to a focused requirement or problem within the context of the framework. Solutions for more complex requirements can be provided by combining several hooks. A discussion and means of describing hooks is given, with a focus on the method of adaption used to fulfill the requirement and the level of support provided for the solution within the framework.
12098131
Context Cube: Flexible and Effective Manipulation of Sensed Context Data
In an effort to support the development of context-aware applications that use archived sensor data, we introduce the concept of the Context Cube based on techniques of data warehousing and data mining. Our implementation of the Context Cube provides a system that supports a multi-dimensional model of context data and with tools for accessing, interpreting and aggregating that data by using concept relationships defined within the real context of the application. We define the Context Cube information model, demonstrate functional applications that we have developed with the system, and explore possible applications that may be developed more easily using our tool.