225,410 research outputs found

    Graph Annotations in Modeling Complex Network Topologies

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    The coarsest approximation of the structure of a complex network, such as the Internet, is a simple undirected unweighted graph. This approximation, however, loses too much detail. In reality, objects represented by vertices and edges in such a graph possess some non-trivial internal structure that varies across and differentiates among distinct types of links or nodes. In this work, we abstract such additional information as network annotations. We introduce a network topology modeling framework that treats annotations as an extended correlation profile of a network. Assuming we have this profile measured for a given network, we present an algorithm to rescale it in order to construct networks of varying size that still reproduce the original measured annotation profile. Using this methodology, we accurately capture the network properties essential for realistic simulations of network applications and protocols, or any other simulations involving complex network topologies, including modeling and simulation of network evolution. We apply our approach to the Autonomous System (AS) topology of the Internet annotated with business relationships between ASs. This topology captures the large-scale structure of the Internet. In depth understanding of this structure and tools to model it are cornerstones of research on future Internet architectures and designs. We find that our techniques are able to accurately capture the structure of annotation correlations within this topology, thus reproducing a number of its important properties in synthetically-generated random graphs

    Rethinking bank business models: the role of intangibles

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    <p>Purpose: This paper provides a new way of rethinking banking models by using qualitative research on intangibles. This is required because the banking sector has been transformed significantly by the changing environment over the past two decades. The 2007-2009 financial crisis also added to concerns about existing bank business models.</p> <p>Design/Methodology approach: Using qualitative data collected from interviews with bank managers and analysts in the UK, this paper develops a grounded theory of bank intangibles.</p> <p>Findings: The model reveals how intangibles and tangible/financial resources interact in the bank value creation process, how they actively respond to environmental changes, how bank intangibles are understood by external observers such as analysts, and how bankers and analysts differ in their views.</p> <p>Research implications: Grounded theory provides the means to further develop bank models as business models and theoretical models. This provides the means to think beyond conventional finance constructs and to relate bank models to a wider theoretical literature concerning intellectual capital, organisational and social systems theory, and ‘performativity’.</p> <p>Practical implications: Such development of bank models and of a systems perspective is critical to the understanding of banks by bankers, by observers and for their ‘critical and reflexive performativity’. It also has implications for systemic risk and bank regulation.</p> <p>Social implications: Improvement in bank models and their use in open and transparent processes are key means to improve public accountability of banks.</p> <p>Originality: The paper reveals the core role of intellectual capital (IC) in banks, in markets, and in developing theory and research at firm and system levels. </p&gt

    Improving the quality of the industrial enterprise management based on the network-centric approach

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    The article examines the network-centric approach to the industrial enterprise management to improve the ef ciency and effectiveness in the implementation of production plans and maximize responsiveness to customers. A network-centric management means the decentralized enterprise group management. A group means a set of enterprise divisions, which should solve by joint efforts a certain case that occurs in the production process. The network-centric management involves more delegation of authority to the lower elements of the enterprise’s organizational structure. The industrial enterprise is considered as a large complex system (production system) functioning and controlled amidst various types of uncertainty: information support uncertainty and goal uncertainty or multicriteria uncertainty. The information support uncertainty occurs because the complex system functioning always takes place in the context of incomplete and fuzzy information. Goal uncertainty or multicriteria uncertainty caused by a great number of goalsestablished for the production system. The network-centric management task de nition by the production system is formulated. The authors offer a mathematical model for optimal planning of consumers’ orders production with the participation of the main enterprise divisions. The methods of formalization of various types of uncertainty in production planning tasks are considered on the basis of the application of the fuzzy sets theory. An enterprise command center is offered as an effective tool for making management decisions by divisions. The article demonstrates that decentralized group management methods can improve the ef ciency and effectiveness of the implementation of production plans through the self-organization mechanisms of enterprise divisions.The work has been prepared with the financial support from the Russian Ministry of Education and Science (Contract No. 02.G25.31.0068 of 23.05.2013 as part of the measure to implement Decision of the Russian Government No. 218)

    Mapping customer needs to engineering characteristics: an aerospace perspective for conceptual design

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    Designing complex engineering systems, such as an aircraft or an aero-engine, is immensely challenging. Formal Systems Engineering (SE) practices are widely used in the aerospace industry throughout the overall design process to minimise the overall design effort, corrective re-work, and ultimately overall development and manufacturing costs. Incorporating the needs and requirements from customers and other stakeholders into the conceptual and early design process is vital for the success and viability of any development programme. This paper presents a formal methodology, the Value-Driven Design (VDD) methodology that has been developed for collaborative and iterative use in the Extended Enterprise (EE) within the aerospace industry, and that has been applied using the Concept Design Analysis (CODA) method to map captured Customer Needs (CNs) into Engineering Characteristics (ECs) and to model an overall ‘design merit’ metric to be used in design assessments, sensitivity analyses, and engineering design optimisation studies. Two different case studies with increasing complexity are presented to elucidate the application areas of the CODA method in the context of the VDD methodology for the EE within the aerospace secto

    What Are the Useful Past Inter-Organizational Relationships (IORs) for Forming Complex IORs?

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    Purpose: The purpose is to explore the relationship between prior and later inter-organizational relationships (IORs) by studying whether past experience can be leveraged on when forming new, more complex, IORs. Methodology: Participation in prior IORs is characterized in terms of both resource- transferring and resource-pooling IORs in home-country networks, while complex IORs are considered those with foreign partners. An empirical test on 366 Italian firms is performed using OLS with robust standard errors. Findings: Both resource-transferring and resource-pooling IORs have non-convergent effects. The former has controversial effects on the base of the position a firm occupies, that in turn affects the structure of interests between the partners. The latter has different effects in line with the information complexity of the objective of the relationship. Research Implications: Results provide support to the idea that structure of interests and information complexity represent \u201cdiscriminating characteristics\u201d that identify salient structural alternatives in the analysis of inter-firm organization. Practical Implications: The paper advances that firms can partially leverage on the exploitation of prior experience in settings that are explorative in nature, by carefully selecting within past experiences. Originality: A distinction between coordination \u201cgiving\u201d and coordination \u201ctaking\u201d IORs is proposed to discern among different types of inter-firm coordination forms

    On the interaction between Autonomous Mobility-on-Demand systems and the power network: models and coordination algorithms

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    We study the interaction between a fleet of electric, self-driving vehicles servicing on-demand transportation requests (referred to as Autonomous Mobility-on-Demand, or AMoD, system) and the electric power network. We propose a model that captures the coupling between the two systems stemming from the vehicles' charging requirements and captures time-varying customer demand and power generation costs, road congestion, battery depreciation, and power transmission and distribution constraints. We then leverage the model to jointly optimize the operation of both systems. We devise an algorithmic procedure to losslessly reduce the problem size by bundling customer requests, allowing it to be efficiently solved by off-the-shelf linear programming solvers. Next, we show that the socially optimal solution to the joint problem can be enforced as a general equilibrium, and we provide a dual decomposition algorithm that allows self-interested agents to compute the market clearing prices without sharing private information. We assess the performance of the mode by studying a hypothetical AMoD system in Dallas-Fort Worth and its impact on the Texas power network. Lack of coordination between the AMoD system and the power network can cause a 4.4% increase in the price of electricity in Dallas-Fort Worth; conversely, coordination between the AMoD system and the power network could reduce electricity expenditure compared to the case where no cars are present (despite the increased demand for electricity) and yield savings of up $147M/year. Finally, we provide a receding-horizon implementation and assess its performance with agent-based simulations. Collectively, the results of this paper provide a first-of-a-kind characterization of the interaction between electric-powered AMoD systems and the power network, and shed additional light on the economic and societal value of AMoD.Comment: Extended version of the paper presented at Robotics: Science and Systems XIV, in prep. for journal submission. In V3, we add a proof that the socially-optimal solution can be enforced as a general equilibrium, a privacy-preserving distributed optimization algorithm, a description of the receding-horizon implementation and additional numerical results, and proofs of all theorem

    A prescriptive approach to qualify and quantify customer value for value-based requirements engineering

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    Recently, customer-based product development is becoming a popular paradigm. Customer expectations and needs can be identified and transformed into requirements for product design with the help of various methods and tools. However, in many cases, these models fail to focus on the perceived value that is crucial when customers make the decision of purchasing a product. In this paper, a prescriptive approach to support value-based requirements engineering (RE) is proposed, describing the foundations, procedures and initial applications in the context of RE for commercial aircraft. An integrated set of techniques, such as means-ends analysis, part-whole analysis and multi-attribute utility theory is introduced in order to understand customer values in depth and width. Technically, this enables identifying the implicit value, structuring logically collected statements of customer expectations and performing value modelling and simulation. Additionally, it helps to put in place a system to measure customer satisfaction that is derived from the proposed approach. The approach offers significant potential to develop effective value creation strategies for the development of new product
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