Decentralized Decision-Making in Complex Network Systems

Sustainable Transportation and Land Use in the Information Society

Supernetworks and the Environment: Foundations and a Virtual Center (2001-2002)

Internet routing---particularly inter-domain routing---suffers from a long list of well-known problems that makes it difficult to innovate new types of end-to-end services and applications. Routing decisions are made locally by routers based on policies that users and their applications have little control over, resulting in routing decisions that are not optimized for users or their applications. Moreover, the "money flow," from customers through a sequence of providers that handle their packets, is determined by business relationships (SLAs) among providers---which change very slowly. One consequence is that it is virtually impossible in today’s Internet to offer an end-to-end service with any real predictability of quality, let alone a guarantee. Moreover, concerns about network providers discriminating against some providers’ content (see the net neutrality debate) add another dimension of complexity. Software-Defined Networking (SDN) is an emerging networking paradigm in which data traffic is routed at the granularity of individual flows by a programmable controller. The ability to route flows at a finer granularity than destination prefixes, and the potential for various stakeholders to express and enforce routing policies for their traffic have made SDN appealing also for inter-domain routing. At the same time, an increasing number of inter-provider connections are being realized at Internet Exchange Points (IXPs). In this context, Software-Defined Internet Exchange Points (SDX) have been proposed as a way for multiple providers to collectively control the routing decisions at Internet Exchange Points (IXPs). Most SDX research has focused on the problems associated with composed and possibly conflicting policies specified by providers or with scalability issues implementing flow-level policies at major IXPs with large numbers of flow.

While SDXs hold great potential, they also exhibit considerable challenges: SDXs offer mechanisms to enforce (certain types of) policies, but they do not define policies. The frameworks needed to define policies are an open area of research. Policies are typically derived from economic relationships established between providers, or between providers and their customers. Moreover, access to, and use of, resources at an SDX itself (e.g., network capacity, processing, and storage) requires that an economic relationship be established between a provider and the SDX. In other words, SDXs act as marketplaces, marketing their resources to providers (e.g., the right to use link bandwidth, processing cycles, and storage), and SDXs provide a way for providers to market their (transit) services to other providers on behalf of their customers. Current SDX designs do not consider these economic relationships and thus omit a critical aspect of Internet operation.

In this proposal, we describe fundamental research aimed at the design of controllers for Software-Defined Internet Exchange Points that can be programmed to implement end-to-end (i.e., inter-domain) routing policies that are tied to explicit economic relationships between network entities.

Co-PIs: Tilman Wolf and Anna Nagurney - UMass Amherst; Jim Griffioen and Ken Calvert - University of Kentucky

Supported by the National Science Foundation

Market forces have had a drastic effect on the shape of services and applications at the edge of the network. Our research proposes a transformative shift in the design of networks that enables sustained innovation in the core of the network using economic principles. We believe that supporting choice is the key aspect of a network architecture that can adapt to emerging solutions for current and future challenges. Choice implies that users can select from alternatives that can be deployed dynamically into the network and reward those that address their needs. We use this interdependency between technological alternatives and economic incentives to create a competitive marketplace for innovative solutions that address current and future challenges in networking. Our proposed work describes fundamental research aimed at the design, development, and prototyping of aspects of a next-generation network architecture where such choices and competition drive innovation at all layers of the protocol stack.

The proposed network design is based on three tightly coupled principles. Our ChoiceNet system aims to (1) encourage alternatives to allow users to choose among a range of services, (2) let users vote with their wallet to reward superior and innovative services, (3) provides the mechanisms to stay informed on available alternatives and their performances. We propose a number of fundamental research problems that address the design of building blocks to provide alternatives in the network, the economic framework for incentives, the necessary monitoring and management components, and the prototyping, education, and outreach efforts. Overall, our work does not aim at reinventing technical solutions to networking problems, but at developing a comprehensive system where these solutions can be deployed and compete to allow the network to adapt to current and future challenges.

Co-PIs: Tilman Wolf and Anna Nagurney - UMass Amherst; Jim Griffioen and Ken Calvert - University of Kentucky; Ilya Baldine - RENCI; Rudra Dutta and George Rouskas - NCSU

Supported by the National Science Foundation

As society has become increasingly dependent on public and private cyber-infrastructure for critical services (e.g. transportation, healthcare, communications, finance), there has been a corresponding increase in the level of sophistication of cyber-threats. Potential attackers range from hackers to organized crime, terrorists and nation states. Intellectual property theft and other white-collar attacks are on the increase. Distributed denial of service attacks disrupt ecommerce operations and provide cover for other types of exploits. Attack vectors and vulnerabilities are increasingly diverse and dynamic. In response, a wide range of new cyber-defense and security systems are moving from passive signature-based schemes (e.g. anti-virus) to more active, intelligence-based techniques. The dynamics of attacker methods and defense techniques motivate a fresh look at cybersecurity risk analysis, its impact on financial organizations and techniques and metrics for optimizing countermeasure investments.

This project isthe second step in a multi-year vision toward understanding these threats and their overall impact on financial organizations. In particular, this proposal addresses some key issues necessary to integrate cybersecurity risk into an overall enterprise risk framework. The first step was a planning proposal in 2012, which reached several initial milestones at defining the models, problems, and solution space of this multi-disciplinary problem. This second step is a one-year exploratory project that advances science, engineering, and management aspects of cyber-risks, as well as providing educational workshops to the ACSC members and seeking larger scale federal funding for a 3-4 year longer term research project.

Co-PIs: Wayne Burleson, Anna Nagurney, Mila Getmansky Sherman, and Senay Solak

Supported by the Advanced Cyber Security Center

Large organizations are challenged by an increasing variety of cybersecurity risks. These risks can be mitigated through investments in various cybersecurity technologies and services. But these organizations also have many other sources of risk that need to be managed, therefore the role and scale of cybersecurity risks needs to be quantified. For example, financial organizations have rigorous and effective techniques for modeling and managing market, credit, operational and reputational risks. Similar methods are needed for cybersecurity. In addition, techniques are needed for optimizing investments in cybersecurity technologies.

The vision of this project is to eventually have: 1) rigorous models for cybersecurity risk, 2) models for costs and benefits of various cybersecurity technologies, and 3) techniques for integrating these models into higher level models that account for other risks and risk management expenditures.

Co-PIs: Wayne Burleson, Christopher Misra, Anna Nagurney, Mila Getmansky Sherman, and Senay Solak

Supported by the Advanced Cyber Security Center

Dynamic Networks with Applications: A Unified Theory of Projected Dynamical Systems and Evolutionary Variational Inequalities with Applications

The world has recently been transformed through events of historical proportions that have dramatically and vividly reinforced the dependence of our societies and economies on complex network systems. Indeed, the interconnectedness, interdependence, and vulnerabilities of organizations, institutions, and other enterprises on critical network systems, including transportation and logistical networks, telecommunication networks, as well as energy networks, have never been more apparent, nor more complex. At the same time, the decisions made by humans, in the form of users, operators and designers of the networks, affect national safety and security, profits and costs, timeliness of deliveries, the quality of the environment, and, hence, the very economic prosperity and vibrancy of our society.

In this project, we will synthesize and advance the theories of projected dynamical systems and evolutionary variational inequalities that have developed in parallel in order to enhance the conceptualization, formulation, and study of human decision-making and the impacts thereof on complex networks and the associated flows (human, vehicular, informational, commodity, energy, environmental, financial, etc.) and prices. The new dynamic network theory will allow for the modeling of multicriteria decision-making by multiple decision-makers interacting on multi-level, multitiered networks who can compete or cooperate in a game theoretic manner, in an environment of heightened risk and uncertainty. Our goal is to study the interrelationships of network systems, across different time scales, along with the effects of human decision-making on prices, costs, and on the induced network flows both theoretically as well as computationally.

Professor Nagurney will be a Science Fellow at the Radcliffe Institute during the 2005-2006 Academic Year.

PI: Anna Nagurney

Supported by the Radcliffe Institute for Advanced Study

Web-Based Tools for Computation and Visualization in Transportation and Logistics

Network systems provide the infrastructure and foundation for the functioning of today’s
societies and economies. They come in many forms and include physical networks such as:  ransportation and logistical networks, telecommunication networks, energy and power networks, as well as more abstract networks comprising: economic and financial networks, environmental networks, social, and knowledge networks. Such network systems are characterized by decentralized decision-making, a large-scale nature, different time scales, as well as distinct governing system equilibrium concepts. Moreover, network systems have historically been studied in isolation and under the assumption that decision-makers are faced with a single criterion that each wishes to optimize (such as profit maximization, cost or time minimization, environmental emission minimization, among others). Recent historical events have dramatically and graphically illustrated the interconnectedness, interdependence, and vulnerability of organizations and enterprises on one another and on such critical network systems as transportation, telecommunications, financial, and energy systems. Indeed, organizations from businesses to governments are now operating in an environment of heightened risk and uncertainty and with increasing weight placed on criteria such as security. The complexity of this new business and organizational environment, coupled with increasing interconnectivity among decisions made and their impact, and the many objectives, often-times conflicting, facing decision-makers, pose major challenges to researchers in modeling, economics, and policy analysis. Indeed, how can one best conceptualize the dynamics underlying complex network systems, abstract them formally through mathematical models and analysis, solve them through rigorous computational procedures, and evaluate the solutions so that one can manage and evaluate perturbations to the systems and adapt accordingly? In this project, we propose to lay down the foundations for the development of a theory of the dynamics of complex networks that will capture the interrelationships among multiple tiers of multicriteria decisionmakers, who seek to optimize their decisions in an environment of risk and uncertainty. The dynamics of the various organizational processes and the product, financial, and information flows will be modeled and qualitatively analyzed using projected dynamical systems theory and its to-be-developed extensions as well as variational inequality theory. Specifically, we will contribute to the study and understanding of Complex Network Systems that underly our economies and societies by:
• developing a theory of complex networks under risk and uncertainty that will allow for multiple tiers of decision-makers and multiple levels of networks that can interact with one another;
• constructing algorithms for tracking the dynamics of the interactions of the decision-makers and the impacts of their decisions on production quantities, shipments, environmental emissions, as well as financial flows, subject to various degrees of information until a benchmark state, such as an equilibrium state, is attained;
• conducting qualitative analysis including sensitivity analysis as well as perturbation analysis to investigate a priori the effects of various changes in the data, the number of decision-makers, their criteria, etc., on the solution values, and
• applying the theory to the concrete applications of global supply chain networks and international financial networks with intermediation.
It is expected that the proposed research will lead not only to novel theoretical contributions but will also yield knowledge of the dynamics of network systems on which the success and competitiveness of our economies, governments, as well as societies are based. The results of the research will have a broad crossdisciplinary reach since the applications under study are of interest to researchers, as well as practitioners, in disciplines ranging from computational economics and management science/operations research to applied mathematics, engineering, and computer science.

Team Leader: Anna Nagurney
Team Members: Patrizia Daniele, University of Catania, Catania, ITALY and Monica Gabriela Cojocaru, Queen’s University, Kingston, Ontario, CANADA

Supported by The Rockefeller Foundation under the Bellagio Center Program

Knowledge Supernetworks: The Modeling and Management of the Dynamics of Complex Business Processes Under Risk and Uncertainty

Decision-makers in organizations including businesses as well as other enterprises today are faced with increasing risk and uncertainty surrounding all aspects of their production process activities from the secure acquisition of inputs, to their transformation, and the ultimate delivery of the products in a timely and cost-effcient manner to the demand markets. The complexity of this new organizational (and business) environment, coupled with increasing interconnectivity among decisions made and their impact, and the many objectives, often-times conflicting, facing decision-makers, pose major challenges to researchers in modeling as well as in management. Indeed, how can one best conceptualize the dynamics of complex organizational processes, abstract them formally through mathematical models and analysis, determine the optimal resource allocations over space and time through rigorous computational procedures, and evaluate the solutions so that one can manage and evaluate perturbations to the systems and adapt accordingly? In this project, we propose to develop a knowledge supernetwork framework to capture the interrelationships within a knowledge organization consisting of multiple tiers of multicriteria decision-makers, who seek to optimize their resource allocations under risk and uncertainty. If the need arises, the members of the organization will also be able to interact with decision-makers in one or more other organizations for purposes of cooperation and coordination. Furthermore, a spectrum of behaviors will be handled within our framework from a completely centralized control yielding a system optimum to a completely decentralized control resulting in a user optimum with differing degrees of control being tackled through game theory. The dynamics of the organizational processes and the resulting product, financial, and information flows over multilevel networks will be modeled and qualitatively analyzed using projected dynamical systems theory and network theory and visualized through computer graphics to be used also as a management tool. Specifically, we will contribute to the study and understanding of the Management of Knowledge Intensive Dynamic Systems by:
(1). Developing a theory of knowledge supernetworks under risk and uncertainty that will allow for multiple tiers of multicriteria decision-makers who are part of a single knowledge organization, such as an extended firm, but, who can also interact with one or more other organizations for purposes of coordination and cooperation. The specific goals of the organization (as well as the decision-makers) will be represented as objective functions, which may include, for example, cost minimization, profit maximization, time minimization, quality maximization, etc., with associated weights which can reflect prioritization. The decision-makers may also control and/or impact other networks, such as logistical and financial ones through their decisions and the optimal allocation of resources, be they human, natural, informational, and/or financial.
(2). Providing benchmarks that will represent the value of the transformation processes and the knowledge-based products through the use of generalized prices, which will be embedded with the weights and the criteria and which will propagate through the knowledge supernetwork over space and time as the decision-makers adjust their resource allocations;
(3). Computing the generalized prices as well as the optimal resource allocations through algorithms that will be developed and implemented for tracking the dynamics of the interactions of the decision-makers and the impacts of their decisions on production quantities, shipments, as well as financial flows, subject to various degrees of information until a steady/optimal state, such as an equilibrium state, is attained;
(4). Conducting qualitative analysis including sensitivity analysis as well as perturbation analysis to investigate a priori the effects of various changes in the data, the number of decision-makers, their criteria, etc., on the solution values;
(5). Developing a computer graphics software package through which managers can quickly evaluate the impact (both visually and through numerical solutions) the effects of a variety of perturbations including, but not limited to: the addition/deletion of decision-makers in the supernetwork; the destruction or loss of connections or “links,” the modification to the underlying criteria functions, changes in the weights associated with the criteria, as well as changes to the resources available whether natural, financial, and/or informational, and
(6). Applying the theory to a concrete application of a knowledge organization. It is expected that the proposed research will lead not only to novel theoretical contributions but will also increase our understanding of knowledge-intensive dynamic systems on which the success and competitiveness of organizations in our network economy are based. The proposed research is unique since it allows for the prediction of the effects on prices and flows of multiple objective decision-making of several (or many) interacting decision-makers, operating under different control mechanisms. The results of the research will have a broad cross-disciplinary reach since the applications under study are of interest to researchers, as well as practitioners, in disciplines ranging from computational economics and management science/operations research to engineering and computer science.

PI: Anna Nagurney
Co-PI: June Dong, SUNY at Oswego

Supported by the National Science Foundation Grant No.: IIS-0002647
 

Supernetworks and the Environment: Foundations and a Virtual Center 2002-2003

In this project, we will leverage the  foundations that we have developed for environmental supernetworks  under our original AT&T Industrial Ecology Fellowship to further both the theory and the breadth and depth of applications. In particular, we will extend the theoretical foundations for decision-making on networks with environmental criteria to include varying degrees of risk and uncertainty. Specific new applications, in turn, that will be explored through modeling, analysis, and
computations will include: supply chain networks with recycling, notably, e-cycling, and the environmental aspects of financial networks with electronic transactions. If time permits, we will also apply the results to telecommuting versus commuting  decision-making and to teleshopping versus shopping decision-making.

As part of the proposed project renewal, we will  continue to support and enhance the Virtual Center for Supernetworks to include additional reports, curricular materials, and links. Finally, we will incorporate the results of the research in courses taught by Professor Nagurney at both the undergraduate and the graduate level and will disseminate the research results both through the Virtual Center and at conferences in the US and abroad.

PI: Anna Nagurney

Supported by an A. T. & T. Foundation Industrial Ecology Faculty Fellowship 2002-2003
 

Supernetworks and the Environment: Foundations and a Virtual Center 2001-2002

In this project, we will develop a theoretical framework, based on supernetworks, for the conceptualization, formulation, and study of decision-making in the Information Age as regards the environment. Supernetworks are over and above existing network systems and include transportation networks and telecommunication networks as special cases. The supernetwork framework will allow one to formalize the alternatives available to decision-makers, to model their individual behavior, typically, characterized by specific criteria which they wish to optimize, and to, ultimately, compute the flows on the supernetwork, which may consist of travelers, product shipments, financial flows, prices, as well as emissions generated. The approach will be theoretical rigorous, graphical in perspective, and predictive in nature. Specific applications that will be explored include: the environmental aspects surrounding supply chain networks with electronic commerce, telecommuting versus commuting decision-making, teleshopping versus shopping decision-making, and transportation and location decisions in the Information Age. In addition, a virtual center for supernetworks and the environment will be established to inform, educate, and to disseminate the outputs of the project which will include both research and curricular materials.

PI: Anna Nagurney

Decentralized Decision-Making in Complex Network Systems

Network systems provide the infrastructure and foundation for the functioning of today's societies and economies. They come in many forms and include physical networks such as: transportation and logistical networks, communication networks, energy and power networks, as well as more abstract networks comprising: economic and financial networks, environmental networks, social, and knowledge networks. Such network systems are characterized by decentralized decision-making, a large-scale nature, different time scales, and distinct governing system equilibrium concepts. Moreover, network systems have historically been studied in isolation and under the assumption that the decision-makers be they, commuters, scientists, workers, firms, etc., are faced with a single criterion that each wishes to optimize.

In this project, we will study complex network systems consisting of the foundational systems of transportation and communication networks. The interplay between these two types of networks and their utilization is becoming increasingly important in the case of telecommuting, intelligent transportation systems, electronic commerce, knowledge networks, and social networks. However, the modeling of such complex network systems has not been fully addressed nor understood. We will investigate such systems theoretically, computationally, visually, through the use of computer graphics, as well as empirically through a specific application. We will make the study of complex network systems with decentralized decision-makers realizable by:

• developing a theory of such complex network systems which will incorporate the individual behavior of the decision-makers and allow for the treatment of multiple criteria for the purpose of prediction and network management;
• constructing algorithms for the solution of such systems, accompanied by convergence analysis, computer implementation, and numerical experimentation;
• developing visualization techniques for the study of complex network systems and phenomena across space and time, and
• applying the theory to the complex network system of knowledge networks and conducting an empirical analysis.

PI: Anna Nagurney
Co-PI's:  June Dong of the State University of New York at Oswego and Patricia L. Mokhtarian of the University of California at Davis

Supported by the National Science Foundation Grant No.: IIS-0002647

Link to Description and results on NSF Wesbite

Sustainable Transportation and Land Use in the Information Society

This project will synthesize the models of sustainable transportation developed at the University of Massachusetts at Amherst with the transportation and land use models developed at the Royal Institute of Technology (KTH) in Stockholm, Sweden, and will extend the resulting integrated models to capture the impact of information technologies on the sustainability of transportation and land use. The research will provide a new theoretical framework  for the investigation and evaluation of alternative policies aimed at sustainability and will enhance the operationalism of the theoretical framework through the use of data obtained in Sweden. The research will be conducted by the US and Swedish collaborators through visits and through extensive communication through the Internet.

PI: Anna Nagurney

Enterprise-Wide Simulation and Analytical Modeling of Comprehensive Freight Movements

The proposed work will develop a multimodal network analysis to simulate the effects of different freight supply chain costs on the movement of goods within the continental United States. Each of the major physical actions, including information exchange, and decisions required to move goods from source to destination will be simulated, including inter-modal, inter-company, and intra-terminal transfers. A method will be developed for simulating large numbers of individual freight shipments by vehicle for a selected commodity class and for assigning them to specific links in the US truck-rail-water-air freight transportation network. Within a supply chain management framework, information and cash flow will be incorporated into the network analysis. Created in the 1960s, the Internet has become an open access, inexpensive, and globally available means for rapid correspondence with the rest of the world. On-line Internet trading is now a major form of business activity. What this rapid transition to e-commerce ultimately implies for the U. S. transportation sector remains to be seen. It is likely to initiate some profound changes in both domestic and international product supply chains, leading to some important new patterns of freight movement which can only be modeled by inter-relating the physical and information networks.

PI: Kitty Hancock of the Department of Civil and Environmental Engineering at the University of Massachusetts at Amherst

Co-PIs: Anna Nagurney and Dr. Frank Southworth of Oak Ridge National Laboratories

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