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Publications

2015

Using the Crowd to Boost Video Annotation Processes: a game based approach

Authors
Pinto, JP; Viana, P;

Publication
CVMP 2015: PROCEEDINGS OF THE 12TH EUROPEAN CONFERENCE ON VISUAL MEDIA PRODUCTION

Abstract
This short paper presents a game for collecting metadata to describe video content. Tags, introduced by registered players on a given timecode of the video, are collected and validated based on a collaborative scoring mechanism that excludes erratic annotations. The system follows a gamification approach for motivating users and includes processes for semantically relating concepts.

2015

Message from the general chairs

Authors
Matos, JS; Alves, JC;

Publication
Proceedings - 41st Euromicro Conference on Software Engineering and Advanced Applications, SEAA 2015

Abstract

2015

Network effects, aftermarkets and the Coase conjecture: A dynamic Markovian approach

Authors
Laussel, D; Long, NV; Resende, J;

Publication
INTERNATIONAL JOURNAL OF INDUSTRIAL ORGANIZATION

Abstract
This paper investigates the expansion of the network of a monopolist firm that produces a durable good and is also involved in the corresponding aftermarket. We characterize the Markov Perfect Equilibrium of the continuous time dynamic game played by the monopolist and the forward-looking consumers, under the assumption that consumers benefit from the subsequent expansion of the network. The paper contributes to the theoretical discussion on the validity of the Coase conjecture, analyzing whether Coase's prediction that the monopolist serves the market in a "twinkling of an eye" remains valid in our setup. We conclude that the equilibrium network development may actually be gradual, contradicting Coase's conjecture. We find that a necessary condition for such a result is the existence of aftermarket network effects that accrue (at least partly) to the monopolist firm.

2015

Decision Support for Energy Contracts Negotiation with Game Theory and Adaptive Learning

Authors
Pinto, T; Vale, Z; Praca, I; Pires, EJS; Lopes, F;

Publication
ENERGIES

Abstract
This paper presents a decision support methodology for electricity market players' bilateral contract negotiations. The proposed model is based on the application of game theory, using artificial intelligence to enhance decision support method's adaptive features. This model is integrated in AiD-EM (Adaptive Decision Support for Electricity Markets Negotiations), a multi-agent system that provides electricity market players with strategic behavior capabilities to improve their outcomes from energy contracts' negotiations. Although a diversity of tools that enable the study and simulation of electricity markets has emerged during the past few years, these are mostly directed to the analysis of market models and power systems' technical constraints, making them suitable tools to support decisions of market operators and regulators. However, the equally important support of market negotiating players' decisions is being highly neglected. The proposed model contributes to overcome the existing gap concerning effective and realistic decision support for electricity market negotiating entities. The proposed method is validated by realistic electricity market simulations using real data from the Iberian market operatorMIBEL. Results show that the proposed adaptive decision support features enable electricity market players to improve their outcomes from bilateral contracts' negotiations.

2015

A microscope for the data centre

Authors
Pereira, N; Tennina, S; Loureiro, J; Severino, R; Saraiva, B; Santos, M; Pacheco, F; Tovar, E;

Publication
INTERNATIONAL JOURNAL OF SENSOR NETWORKS

Abstract
Data centres are large energy consumers. A large portion of this power consumption is due to the control of physical parameters of the data centre (such as temperature and humidity). However, these physical parameters are tightly coupled with computations, and even more so in upcoming data centres, where the location of workloads can vary substantially due, for example, to workloads being moved in the cloud infrastructure hosted in the data centre. Therefore, managing the physical and compute infrastructure of a large data centre is an embodiment of a cyber-physical system (CPS). In this paper, we describe a data collection and distribution architecture that enables gathering physical parameters of a large data centre at a very high temporal and spatial resolution of the sensor measurements. We detail this architecture and define the structure of the underlying messaging system that is used to collect and distribute the data.

2015

Using PVS to support the analysis of distributed cognition systems

Authors
Masci, Paolo; Curzon, Paul; Furniss, Dominic; Blandford, Ann;

Publication
ISSE

Abstract
The rigorous analysis of socio-technical systems is challenging, because people are inherent parts of the system, together with devices and artefacts. In this paper, we report on the use of PVS as a way of analysing such systems in terms of distributed cognition. Distributed cognition is a conceptual framework that allows us to derive insights about plausible user trajectories in socio-technical systems by exploring what information in the environment provides resources for user action, but its application has traditionally required substantial craft skill. DiCoT adds structure and method to the analysis of socio-technical systems from a distributed cognition perspective. In this work, we demonstrate how PVS can be used with DiCoT to conduct a systematic analysis. We illustrate how a relatively simple use of PVS can help a field researcher to (i) externalise assumptions and facts, (ii) verify the consistency of the logical argument framed in the descriptions, (iii) help uncover latent situations that may warrant further investigation, and (iv) verify conjectures about potential hazards linked to the observed use of information resources. Evidence is also provided that formal methods and empirical studies are not alternative approaches for studying a socio-technical system, but that they can complement and refine each other. The combined use of PVS and DiCoT is illustrated through a case study concerning a real-world emergency medical dispatch system. © 2013, Springer-Verlag London.

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