A scalability analysis of grid allocation mechanisms

This article examines the broker's behavior with regard to a varying number of participating nodes and shows that incremental losses have to be accepted in central resource allocation when introducing new nodes. --Grid Computing

A theoretical and computational basis for CATNETS

The main content of this report is the identification and definition of market mechanisms for Application Layer Networks (ALNs). On basis of the structured Market Engineering process, the work comprises the identification of requirements which adequate market mechanisms for ALNs have to fulfill. Subsequently, two mechanisms for each, the centralized and the decentralized case are described in this document. These build the theoretical foundation for the work within the following two years of the CATNETS project. --Grid Computing

Theoretical and Computational Basis for Economical Ressource Allocation in Application Layer Networks - Annual Report Year 1

This paper identifies and defines suitable market mechanisms for Application Layer Networks (ALNs). On basis of the structured Market Engineering process, the work comprises the identification of requirements which adequate market mechanisms for ALNs have to fulfill. Subsequently, two mechanisms for each, the centralized and the decentralized case are described in this document. --Grid Computing

Sustainable consumption: towards action and impact. : International scientific conference November 6th-8th 2011, Hamburg - European Green Capital 2011, Germany: abstract volume

This volume contains the abstracts of all oral and poster presentations of the international scientific conference „Sustainable Consumption – Towards Action and Impact“ held in Hamburg (Germany) on November 6th-8th 2011. This unique conference aims to promote a comprehensive academic discourse on issues concerning sustainable consumption and brings together scholars from a wide range of academic disciplines. In modern societies, private consumption is a multifaceted and ambivalent phenomenon: it is a ubiquitous social practice and an economic driving force, yet at the same time, its consequences are in conflict with important social and environmental sustainability goals. Finding paths towards “sustainable consumption” has therefore become a major political issue. In order to properly understand the challenge of “sustainable consumption”, identify unsustainable patterns of consumption and bring forward the necessary innovations, a collaborative effort of researchers from different disciplines is needed

Self-Organising Networks in Complex Infrastructure Projects: The Case of London Bank Station Capacity Upgrade Project

Managing large infrastructure projects remains a thorny issue in theory and practice. This is mainly due to their increasingly interconnected, interdependent, multilateral, nonlinear, unpredictable, uncontrollable, and rapidly changing nature. This study is an attempt to demystify the key issues to the management of large construction projects, arguing that these projects are delivered through networks that evolve in ways that we do not sufficiently understand as yet. The theoretical framework of this study is grounded in Complexity Theory; a theory resulted in a paradigm shift when it was first introduced to project management post-2000 but is yet to be unpacked in its full potential. The original contribution of the study is predicated on perceiving large construction projects as evolving complex systems that involves a high degree of self‐organisation. This is a process that transitions contractually static prescribed roles to dynamic network roles, comprising individuals exchanging information. Furthermore, by placing great emphasis upon informal communications, this study demonstrates how self-organising networks can be married with Complexity Theory. This approach has the potential to make bedfellows around the concept of managing networks within a context of managing projects; a concept that is not always recognised, especially in project management. With the help of social network analysis, two snapshots from Bank Station Capacity Upgrade Project Network were analysed as a case study. Findings suggest that relationships and hence network structures in large construction projects exhibit small-world topology, underlined by a high degree of sparseness and clustering. These are distinct structural properties of self-organising networks. Evidence challenges the theorisation about self-organisation which largely assumes positive outcomes and suggests that self-organising could open up opportunities yet also create constraints. This helps to provide further insights into complexity and the treatment of uncertainty in large projects. The study concludes with detailed recommendations for research and practice

Multi-attribute demand characterization and layered service pricing

As cloud computing gains popularity, understanding the pattern and structure of its workload is increasingly important in order to drive effective resource allocation and pricing decisions. In the cloud model, virtual machines (VMs), each consisting of a bundle of computing resources, are presented to users for purchase. Thus, the cloud context requires multi-attribute models of demand. While most of the available studies have focused on one specific attribute of a virtual request such as CPU or memory, to the best of our knowledge there is no work on the joint distribution of resource usage. In the first part of this dissertation, we develop a joint distribution model that captures the relationship among multiple resources by fitting the marginal distribution of each resource type as well as the non-linear structure of their correlation via a copula distribution. We validate our models using a public data set of Google data center usage. Constructing the demand model is essential for provisioning revenue-optimal configuration for VMs or quality of service (QoS) offered by a provider. In the second part of the dissertation, we turn to the service pricing problem in a multi-provider setting: given service configurations (qualities) offered by different providers, choose a proper price for each offered service to undercut competitors and attract customers. With the rise of layered service-oriented architectures there is a need for more advanced solutions that manage the interactions among service providers at multiple levels. Brokers, as the intermediaries between customers and lower-level providers, play a key role in improving the efficiency of service-oriented structures by matching the demands of customers to the services of providers. We analyze a layered market in which service brokers and service providers compete in a Bertrand game at different levels in an oligopoly market while they offer different QoS. We examine the interaction among players and the effect of price competition on their market shares. We also study the market with partial cooperation, where a subset of players optimizes their total revenue instead of maximizing their own profit independently. We analyze the impact of this cooperation on the market and customers' social welfare