Sonia Mendoza

A Distributed Event Service for Adaptive Group Awareness

This paper is directly focused on the design of middleware functions to support a distributed cooperative authoring environment on the World Wide Web. Using the advanced storage and access functions of the PInAS middleware, co-authors can produce fragmented and replicated documents in a structured, consistent and efficient way. However, despite it provides elaborated, concerted, secure and parameterizable cooperative editing support and mechanisms, this kind of applications requires a suited and efficient inter-application communication service to design and implement flexible, efficient, and adapted group awareness functionalities.Thus, we developed a proof-of-concept implementation of a centralized version of a Distributed Event Management Service that allows to establish communication between cooperative applications, either in distributed or centralized mode. As an essential component for the development of cooperative environments, this Distributed Event Management Service allowed us to design an Adaptive Group Awareness Engine whose aim is to automatically deduce and adapt co-authors cooperative environments to allow them collaborate closer. Thus, this user associated inference engine captures the application events corresponding to authors actions, and uses its knowledge and rule bases, to detect co-authors complementary or related work, specialists, or beginners, etc. Its final goal is to propose modifications to the author working environments, application interfaces, communication or interaction ways, etc.

Multi-user interaction with public screens using mobile devices

Public screens can now be found in many places, from shopping malls and airports to museums and restaurants, and even in the outside walls of tall buildings. These public screens usually convey contextual information to the public, and even though some of them support interactivity via touchscreen, the same information is always displayed to all its users regardless of their interests or preferences. On the other hand, mobile devices in general have shown great success by substantially increasing their numbers and their power. As such it is common to start viewing them as tools to achieve previously unattainable capabilities. In this article we engage the idea of using mobile devices to allow multiple users to simultaneously interact with public screens. As a matter of motivation, we consider a few potential applications that range from the marketing to the entertaining industry. We discuss some key characteristics that are desired on a platform that supports this kind of interaction. Finally we present PACMEN, a platform that supports the development of applications oriented to allow multiple users to simultaneously interact with public screens using mobile devices.

PIÑAS: Supporting a Community of Co-authors on the Web

To provide efficient support for collaborative writing to a community of authors is a complex and demanding task, members need to communicate, coordinate, and produce in a concerted fashion in order to obtain a final version of the documents that meets overall expectations. In this paper, we present the PINAS middleware, a platform that provides potential and actual collaboration spaces, as well as specific services customized to support collaborative writing on the Web. We start by introducing PINAS Collaborative Spaces and an extended version of Doc2U, the current tool that implements them, that integrate and structure a suite of specialized project and session services. Later, a set of services for the naming, identification, and shared management of authors, documents and resources in a replicated Web architecture is presented. Finally, a three-tier distributed architecture that organizes these services and a final discussion on how they support a community of authors on the Web is presented.

A flexible distribution service for a co-authoring environment on the Web

The PINAS platform provides support to collaboratively and consistently produce shared documents in the Web environment. Such documents may include possible costly multimedia resources, whose management raises important issues due to the constraints imposed by Web technology. In this paper, we present a flexible service for distributing shared Web documents across authoring group sites. To carry out distribution, our approach takes into account the current organization of the involved sites, the access rights granted to the co-authors and the site storage capabilities. Scenarios are used to motivate the need for robust mechanisms for the management of shared Web documents and their resources, and to illustrate how our approach addresses these issues.

Adaptive Resource Management in the PIÑAS Web Cooperative Environment

The PINAS Web cooperative environment allows distributed authors working together to produce shared documents in a consistent way. The management of shared resources in such an environment raises important technical issues due to the constraints imposed by Web technology. An elaborated group awareness function is provided that allows each author notifying his contributions to other authors, and controlling the way by which other contributions are integrated into his/her environment. In order to support this function, essential to every groupware application, we designed a self-adaptive cooperative environment. We propose a new way of structuring Web documents to be considered as independent resource containers with their corresponding management context. This representation of information simplifies the design of mechanisms to share, modify and update documents and their resources in a consistent and controlled way. Scenarios are used to motivate the need for robust mechanisms for the management of shared Web documents and to illustrate how the extensions presented address these issues.

Fault tolerance in heterogeneous multi-cluster systems through a task migration mechanism

The GRID computing paradigm consists of multiple heterogeneous distributed clusters connected by heterogeneous network interfaces. One advantage of this paradigm is to analyze massive amounts of data employing computing resources at different geographic places with different platforms. However in order to harness the power of those resources, many problems must be solved. In this work we deal with the problem of fault tolerance on heterogeneous computer systems. Our proposal aims to ease the process of recovery when system failures are detected at runtime avoiding the necessity for application restarts. Our proposal works through a set of services that performs transparent task migration over the computing nodes, hiding the complexity related with error handling when a hybrid programming model based on Open MPI and OpenCL is employed.

Facilitating resource sharing and selection in ubiquitous multi-user environments

Mobile technologies have increased the interest of industry and academia in providing users with information and services anytime and anywhere. Some services are customized according to the users’ characteristics, attempting to create ubiquitous environments that enable such users to share and discover resources. However, research that addresses the creation of these environments is scant. In this article, we go further than single-user pervasive systems, by developing a support that manages shared resources in ubiquitous multi-user environments. Our contribution is a semantic matchmaking service capable of finding the most suitable resources that satisfy the users’ requirements. This service processes the users’ requests, their context, and the community participating in the resource sharing process, by respecting restrictions, the natural interaction among participants, and the changes that this interaction produces. We model the environment, shared resources, and users as dynamic entities that generate new information, which might affect the availability states of such resources. These states have been defined through the Contextual-Graphs formalism to incorporate new knowledge that can refine, extend, or customize such states, according to the users’ habits. Our matchmaking service has been deployed across the Computer Science Department of CINVESTAV-IPN research center, where it has been validated by means of several test cases.

An architecture for supporting face-to-face mobile interaction

A lot of groupware systems for stationary computers have been already developed, but a question remains open: How can we achieve a proportional diversity of this kind of systems for mobile devices? In this paper, we try to answer this question by proposing an architecture for a development toolkit, which aims to provide reusable building tools that facilitate the implementation of mobile groupware systems intended to support collaborative authoring with support for concurrent accesses. The design of the toolkit architecture is motivated by the dificulties found in the development of software for mobile devices, e.g., unexpected network disconnections. Particularly, the proposed tools offer functionality for consistency maintenance of shared information using Operational Transformation, network communication over Bluetooth-based ad-hoc networks, and group awareness support employing an event-based interface.

Collaborative Web Authoring of 3D Surfaces Using Augmented Reality on Mobile Devices

3D Surfaces are widely employed to model geometric assets (e.g., mountains on a landscape), which are used in digital animations and video games. A single surface commonly needs to be created and modified by a group of collaborators, but most of the 3D content creation applications are essentially single-user. In addition, such surfaces are visualized in 2D projections, causing confusion to new users, when imagining their shape in 3D. In this paper, we propose a novel approach based on Augmented Reality (AR) to the task of collaboratively authoring surfaces on the Web using mobile devices. We rely on AR technology to help collaborators to easily understand the shape of the surfaces 3D representation, and we provide them with the basic authoring tools to intuitively modify its shape. To support real time face-to-face interaction, we implement an object sharing scheme, which according to our results is enough in practice. In this way, our approach is able to create a new online collaborative setting in which a group of collocated participants, each one using a mobile device, or connected to the Web, can concurrently modify a surface, while visualizing it in their own real environment through AR.

AR-based Modeling of 3D Objects in Multi-user Mobile Environments

In animations and video games, Digital Elevation Maps (DEMs) are commonly used to model geometric assets, e.g., terrains on a landscape. When a DEM is edited by a group of collaborators, they are constrained to access the elevation data from their PC following a turn-taking policy, since most of the applications are essentially single-user. Furthermore, the DEM is visualized in 2D, causing some degree of confusion to new users when imagining the DEM shape in 3D. In this paper, we propose a novel approach to the collaborative modeling of DEMs on mobile devices. Our approach uses Augmented Reality (AR) to help collaborators to easily understand the DEM’s 3D representation and provides them with basic editing tools to modify the DEM shape in an intuitive manner. In addition, we implement an object sharing scheme, in order to support face-to-face interaction in real-time. By means of this approach, it is possible to create an original collaboration setting, in which a group of collocated colleagues, each carrying a mobile device, can concurrently create and modify the same DEM, while visualizing it using AR-technology. As shown by our results, the workload perceived by the users of our DEM editor is small.