PACMAS: A Personalized, Adaptive, and Cooperative MultiAgent System Architecture

In this paper, a generic architecture, designed to support the implementation of applications aimed at managing information among different and heterogeneous sources, is presented. Information is filtered and organized according to personal interests explicitly stated by the user. User pro- files are improved and refined throughout time by suitable adaptation techniques. The overall architecture has been called PACMAS, being a support for implementing Personalized, Adaptive, and Cooperative MultiAgent Systems. PACMAS agents are autonomous and flexible, and can be made personal, adaptive and cooperative, depending on the given application. The peculiarities of the architecture are highlighted by illustrating three relevant case studies focused on giving a support to undergraduate and graduate students, on predicting protein secondary structure, and on classifying newspaper articles, respectively

A software toolkit for web-based virtual environments based on a shared database

We propose a software toolkit for developing complex web-based user interfaces, incorporating such things as multi-user facilities, virtual environments (VEs), and interface agents. The toolkit is based on a novel software architecture that combines ideas from multi-agent platforms and user interface (UI) architectures. It provides a distributed shared database with publish-subscribe facilities. This enables UI components to observe the state and activities of any other components in the system easily. The system runs in a web-based environment. The toolkit is comprised of several programming and other specification languages, providing a complete suite of systems design languages. We illustrate the toolkit by means of a couple of examples

An Instance-Oriented Approach to Constructing Product Lines from Layers

The Model/View/Controller (MVC) paradigm, and its many variants, is a cornerstone of decoupling within object-oriented design. MVC leads to clear reuse benefits regarding the class hierarchies for the model and view elements. In practice, however, the controllers appear to defy reuse, most likely because they encapsulate specialized business logic. Within an effective product line, however, such specialized logic must be reused. We combine the MVC paradigm with feature-oriented programming (FOP) to produce a novel instance-oriented design pattern for layers that brings reusability back to controllers. We demonstrate the effectiveness of our approach using a product-line example of a solitaire game engine

HardScope: Thwarting DOP with Hardware-assisted Run-time Scope Enforcement

Widespread use of memory unsafe programming languages (e.g., C and C++) leaves many systems vulnerable to memory corruption attacks. A variety of defenses have been proposed to mitigate attacks that exploit memory errors to hijack the control flow of the code at run-time, e.g., (fine-grained) randomization or Control Flow Integrity. However, recent work on data-oriented programming (DOP) demonstrated highly expressive (Turing-complete) attacks, even in the presence of these state-of-the-art defenses. Although multiple real-world DOP attacks have been demonstrated, no efficient defenses are yet available. We propose run-time scope enforcement (RSE), a novel approach designed to efficiently mitigate all currently known DOP attacks by enforcing compile-time memory safety constraints (e.g., variable visibility rules) at run-time. We present HardScope, a proof-of-concept implementation of hardware-assisted RSE for the new RISC-V open instruction set architecture. We discuss our systematic empirical evaluation of HardScope which demonstrates that it can mitigate all currently known DOP attacks, and has a real-world performance overhead of 3.2% in embedded benchmarks

Evaluating User Interface Management Systems based on Quality Attributes and Unit Operations

Software architecture is an essential early stage in the software design process. In this stage, the architect should give the quality attributes a special consideration because a good level of meeting these attributes can be performed by well-designed architecture. This means that there is a close relationship between quality attributes and software architecture. However, quality attributes can be achieved through the appropriate application of a set of unit operations. A unit operation is a systematic designing operation that can be applied directly to system architecture. Architectural styles (patterns) include high level design decisions that address quality attributes. Many general architectural styles are defined in the literature. For the domain of user interactive systems there are many architectural styles that address some important quality attributes. In many cases, it is essential to evaluate software styles in terms of their achievement of the required quality attributes by analyzing the relationships between these attributes, unit operations, and styles. This evaluation can help and facilitate the process of selecting a specified style. In this paper the authors propose a structured quantitative evaluation method to show a rank of four wellknown user interface management systems (UIMSs) in terms of their supporting a set of six important selected quality attributes

An adaptive architecture for presenting interactive media onto distributed interfaces

This paper introduces an adaptive architecture for presenting interactive timed media onto distributed networked devices. The architecture is put into the test in a storytelling application for children. The interactive story is documented in StoryML, an XML-based language, and presented to multiple interface devices organized in an agent-based architecture. This allows the separation of the content from concrete physical devices, the definition of abstract media objects and the automatic adaptation of the same content to different environments of physical devices. Since both the content and the interaction are timed, issues of streaming and synchronization in this architecture are also addressed.</p

ISML: an interface specification meta-language

In this paper we present an abstract metaphor model situated within a model-based user interface framework. The inclusion of metaphors in graphical user interfaces is a well established, but mostly craft-based strategy to design. A substantial body of notations and tools can be found within the model-based user interface design literature, however an explicit treatment of metaphor and its mappings to other design views has yet to be addressed. We introduce the Interface Specification Meta-Language (ISML) framework and demonstrate its use in comparing the semantic and syntactic features of an interactive system. Challenges facing this research are outlined and further work proposed