Mattijs Ghijsen

Towards an Infrastructure Description Language for Modeling Computing Infrastructures

This paper describes the Infrastructure and Network Description Language (INDL). The aim of INDL is to provide technology independent descriptions of computing infrastructures. These descriptions include the physical resources and the network infrastructure that connects these resources. The description language also provides the necessary vocabulary to describe virtualization of resources and the services offered by these resources. Furthermore, the language can be easily extended to describe federation of different existing computing infrastructures, specific types of (optical) equipment and also behavioral aspects of resources, for example, their energy consumption. Before we introduce INDL we first discuss a number of modeling efforts that have lead to the development of INDL, namely the Network Description Language, the Network Markup Language and the CineGrid Description Language. We also show current applications of INDL in two EU-FP7 projects: NOVI and GEYSERS. We demonstrate the flexibility and extensibility of INDL to cater the specific needs of these two projects.

A semantic-web approach for modeling computing infrastructures

This paper describes our approach to modeling computing infrastructures. Our main contribution is the Infrastructure and Network Description Language (INDL) ontology. The aim of INDL is to provide technology independent descriptions of computing infrastructures, consisting of processing and storage resources and the network topology that connects these resources. INDL also provides descriptions for virtualization of resources and the services offered by resources. We build our infrastructure model upon the Network Markup Language (NML). Although INDL is a stand-alone model, it can be easily connected with the NML model. In this paper we show how INDL and NML are used as a basis for models used in three different applications: the CineGrid infrastructure, the Logical Infrastructure Composition Layer in the GEYSERS EU-FP7 project and the NOVI federation platform. Furthermore, we show the use of INDL for monitoring energy aspects of computing infrastructures and its application for workflow planning on computing infrastructures.

On-demand provisioning of Cloud and Grid based infrastructure services for collaborative projects and groups

Effective use of existing network and IT infrastructure can be achieved by providing combined network and IT resources on-demand as infrastructure services that are capable of supporting complex technological processes, scientific experiments, and collaborative groups of researchers and applications. This paper provides a short overview of existing standards and technologies and refers to ongoing projects. We also describe experiences in developing an architectural framework and tools for combined on-demand network and Grid/Cloud service provisioning. The paper proposes an architectural framework for on-demand infrastructure service provisioning comprising of three main components: the Composable Services Architecture (CSA) that intends to provide a conceptual and methodological framework for developing dynamically configurable virtualised infrastructure services; the Infrastructure Services Modeling Framework (ISMF) that provides a basis for the infrastructure resources virtualisation and management, including description, discovery, modeling, composition and monitoring; and the Service Delivery Framework (SDF) that provides a basis for defining the whole composable services life cycle management and supporting infrastructure services. We discuss implementation suggestions for the defined architectural components and provides information about the ongoing developments of the GEMBus which is considered as a middleware framework for CSA.

Towards a framework for agent coordination and reorganization, AgentCoRe

Research in the area of Multi-Agent System (MAS) organization has shown that the ability for a MAS to adapt its organizational structure can be beneficial when coping with dynamics and uncertainty in the MASs environment. Different types of reorganization exist, such as changing relations and interaction patterns between agents, changing agent roles and changing the coordination style in the MAS. In this paper we propose a framework for agent Coordination and Reorganization (AgentCoRe) that incorporates each of these aspects of reorganization. We describe both declarative and procedural knowledge an agent uses to decompose and assign tasks, and to reorganize. The RoboCupRescue simulation environment is used to demonstrate how AgentCoRe is used to build a MAS that is capable of reorganizing itself by changing relations, interaction patterns and agent roles.

Energy efficiency considerations in integrated IT and optical network resilient infrastructures

The European Integrated Project GEYSERS - Generalised Architecture for Dynamic Infrastructure Services - is concentrating on infrastructures incorporating integrated optical network and IT resources in support of the Future Internet with special emphasis on cloud computing. More specifically GEYSERS proposes the concept of Virtual Infrastructures over one or more interconnected Physical Infrastructures comprising both network and IT resources. Taking into consideration the energy consumption levels associated with the ICT today and the expansion of the Internet in size and complexity, that incurring increased energy consumption of both IT and network resources, energy efficient infrastructure design becomes critical. To address this need, in the framework of GEYSERS, we propose energy efficient design of infrastructures incorporating integrated optical network and IT resources, supporting resilient end-to-end services. Our modeling results quantify significant energy savings of the proposed solution by jointly optimizing the allocation of both network and IT resources.

Facial signs of affect during tutoring sessions

An emotionally intelligent tutoring system should be able to taking into account relevant aspects of the mental state of the student when providing feedback. The student’s facial expressions, put in context, could provide cues with respect to this state. We discuss the analysis of the facial expression displayed by students interacting with an Intelligent Tutoring System and our attempts to relate expression, situation and mental state building on Scherer’s component process model of emotion appraisal.

Market-based coordinated charging of electric vehicles on the low-voltage distribution grid

This paper presents a market based coordination mechanism for charging electric vehicles. In market based coordination, a virtual market is used to match supply and demand of a commodity. The goal is to limit the impact of the electric vehicles on the low voltage distribution grid. First it is shown how, in general, the trading volume on a commodity market with a single supplier can be controlled by the shape of the bid function of the supplier. This approach is then translated to an electricity market where the transformer is the single supplier and the households and electric vehicles are the buyers of electricity. A number of test-scenarios are created with a reference distribution grid in which several vehicles are plug-in hybrid electric or fully electric. Load flow analysis shows that if no coordination takes place, the peak load exceeds the tranformers rating and the voltage drops below the norm. Simulations show that the market-based coordination mechanism is indeed capable of reducing the peak load to an acceptable level and keeps the under-voltage within an acceptable range.

Agent Decision Making for Dynamic Selection of Coordination Mechanisms

In this paper we present a decision making framework to enable agents to dynamically select a coordination mechanism. To demonstrate our approach we introduce an abstract task environment in which agents have to cooperate to achieve their goals. These agents are capable of using two coordination mechanisms, a centralized and a decentralized mechanism. We show how the decision making framework is operationalized in this abstract task environment. Furthermore, in an experiment we compare the performance of two static organizations with an organization in which agents have the ability to switch between coordination mechanisms. Results show that the ability to switch improves performance of the MAS.

Trying too hard: effects of mobile agents' (Inappropriate) social expressiveness on trust, affect and compliance

Mobile services can provide users with information relevant to their current circumstances. Distant services in turn can acquire local information from people in an area of interest. Socially expressive agent behaviour has been suggested as a way to build reciprocal relationships and to increase user response to such requests. This between-subject, Wizard-of-Oz experiment aimed to investigate the potential of such behaviours. 44 participants performed a search task in an urgent context while being interrupted by a mobile agent that both provided and requested information. The socially expressive behaviour shown in this study did not increase compliance to requests; it instead reduced trust in provided information and compliance to warnings. It also negatively impacted the affective experience of users scoring lower on empathy as a personality trait. Inappropriate social expressiveness can have serious consequences; we here elaborate on the reasons for our negative results.

Adaptive hierarchical multi-agent organizations

In this chapter, we discuss the design of adaptive hierarchical organizations for multi-agent systems (MAS). Hierarchical organizations have a number of advantages such as their ability to handle complex problems and their scalability to large organizations. By introducing adaptivity in the structure of hierarchical MAS organizations, we enable agents to balance resources in their organization. We will first provide a number of generic principles for the design of hierarchical MAS organizations. We show how these principles are used to design three different hierarchical organizations for a search and rescue task in the RoboCupRescue simulation environment. The first two of these organizations are static, and the third is able to adapt its structure. An empirical study on the performance of these three organizations shows that the dynamic organization performs better than the two static organizations.