Two Innovative Coalition Formation Models for Dynamic Task Allocation in Disaster Rescues

This paper addresses the problem of multi-objective coalition formation for task allocation. In disaster rescue, due to the dynamics of environments, heterogeneity and complexity of tasks as well as limited available agents, it is hard for the single-objective and single (task)-to-single (agent) task allocation approaches to handle task allocation in such circumstances. To this end, two multi-objective coalition formation for task allocation models are proposed for disaster rescues in this paper. First, through coalition formation, the proposed models enable agents to cooperatively perform complex tasks that cannot be completed by single agent. In addition, through adjusting the weights of multiple task allocation objectives, the proposed models can employ the linear programming to generate more adaptive task allocation plans, which can satisfy different task allocation requirements in disaster rescue. Finally, through employing the multi-stage task allocation mechanism of the dynamic programming, the proposed models can handle the dynamics of tasks and agents in disaster environments. Experimental results indicate that the proposed models have good performance on coalition formation for task allocation in disaster environments, which can generate suitable task allocation plans according to various objectives of task allocation.     

Data-Driven Leader-Follower Output Synchronization for Networked Non-Linear Multi-Agent Systems with Switching Topology and Time-Varying Delays

This paper studies the output synchronization problem for a class of networked non-linear multi-agent systems with switching topology and time-varying delays. To synchronize the outputs, a leader is introduced whose connectivity to the followers varies with time, and a novel data-driven consensus protocol based on model free adaptive control is proposed, where the reference input of each follower is designed to be the time-varying average of the neighboring agents’ outputs. Both the case when the leader is with a prescribed reference input and the case otherwise are considered. The proposed protocol allows for time-varying delays, switching topology, and does not use the agent structure or the dynamics information implicitly or explicitly. Sufficient conditions are derived to guarantee the closed-loop stability, and conditions for consensus convergence are obtained, where only a joint spanning tree is required. Numerical simulations and practical experiments are conducted to demonstrate the effectiveness of the proposed protocol.     

Contours and Tight Clusters

Nested clusters arise independently in graph partitioning and in the study of contours. We take a step toward unifying these two instances of nested clusters. We show that the graph theoretical tight clusters introduced by Dress, Steel, Moulton and Wu in 2010 are a special case of nested clusters associated to contours.     

An empirical investigation on the risk-return relationship of carbon future market

This paper examines the risk-return relationship for the carbon future market during Phases I, II and III of the European Union Emission Trading Scheme (EU ETS). The risk factors derived from the newly developed LSW model, are embedded into a GARCH framework. This new specification is compared with several GARCH-M type models analyzing the risk-return relationship in the carbon market. The results show that the new specification consistently achieves a good fit and possesses superior explanatory power for the European Union Allowance (EUA) data. Some policy suggestions regarding market efficiency are also provided.     

Systemic Design for Applying the Combined Use of SSM and CDA to Social Practices

In this paper, we propose a framework for applying the combined use of soft systems methodology (SSM) and critical discourse analysis (CDA) based on social semiotic systemic functional linguistics to social practices. In the social practice, ‘participation’ mode of Checkland’s SSM is used for ‘problem-solving’ whilst CDA is used to problematize ‘problem-solving’ processes within the practice. During the meta-process of problematization of our research, we used Churchman’s systems approach and its theory of ‘boundary critique’ in order to explore issues such as governance, inequality of power, and social values within the organization examined for this study. In other words, the process-oriented methodology proposed in this paper consists of two processes: that of ‘problem-solving’ based on SSM and of problematization of naturalized discourse from the perspective of CDA and two phases of boundary critique in social practice. A detailed account of a case study of Korean social enterprise is given to demonstrate how our proposed framework of the combined use of SSM and CDA is applied into practice. Reflecting the outcome of the case study, this paper argues that critical social research from systemic inquiry using what we call ‘process-oriented methodology’ is useful to address some of the social and complex issues related to understanding dynamic relation between power and discourse amongst participants in the social enterprise in Korean contexts.