Patrizia Daniele

Equilibrium problems and variational models

On Vector Quasi-Equilibrium Problems.- 1. Introduction.- 2. Preliminaries.- 3. Existence Results.- 4. Some Applications.- References.- The Log-Quadratic Proximal Methodology in Convex Optimization Algorithms and Variational Inequalities.- 1. Introduction.- 2. Lagrangians and Proximal Methods.- 2.1. The quadratic augmented Lagrangian.- 2.2. Proximal Minimization Algorithms.- 2.3. Entropic Proximal Methods and Modified Lagrangians.- 2.4. Difficulties with Entropic Proximal Methods.- 2.5. Toward Solutions to Difficulties.- 3. The Logarithmic-Quadratic Proximal Framework.- 3.1. The LQ-Function and its Conjugate: Basic Properties.- 3.2. The Logarithmic-Quadratic Proximal Minimization.- 4. The LQP in Action.- 4.1. Primal LQP for Variational Inequalities over Polyhedra.- 4.2. Lagrangian Methods for convex optimization and variational inequalities.- 4.3. Dual and Primal-Dual Decomposition schemes.- 4.4. Primal Decomposition: Block Gauss-Seidel Schemes for Linearly constrained Problems.- 4.5. Convex Feasibility Problems.- 4.6. Bundle Methods in Nonsmooth Optimization.- References.- The Continuum Model of Transportation Problem.- 1. Introduction.- 2. Calculus of the solution.- References.- The Economic Model for Demand-Supply Problems.- 1. Introduction.- 2. The first phase: formalization of the equilibrium.- 3. The second phase: formalization of the equilibrium.- 4. The dependence of the second phase on the first one.- 5. General model.- 6. Example.- References.- Constrained Problems of Calculus of Variations Via Penalization Technique.- 1. Introduction.- 2. Statement of the problem.- 3. An equivalent statement of the problem.- 4. Local minima.- 5. Penalty functions.- 6. Exact penalty functions.- 6.1. Properties of the function ?.- 6.2. Properties of the function G.- 6.3. The rate of descent of the function ?.- 6.4. An Exact Penalty function.- 7. Necessary conditions for an Extremum.- 7.1. Necessary conditions generated by classical variations.- 7.2. Discussion and Remarks.- References.- Variational Problems with Constraints Involving Higher-Order Derivatives.- 1. Introduction.- 2. Statement of the problem.- 3. An equivalent statement of the problem.- 4. Local minima.- 5. Properties of the function ?.- 5.1. A classical variation of z.- 5.2. The case z ? Z.- 5.3. The case z ? Z.- 6. Exact penalty functions.- 6.1. Properties of the function G.- 6.2. An Exact Penalty function.- 7. Necessary conditions for an Extremum.- References.- On the strong solvability of a unilateral boundary value problem for Nonlinear Parabolic Operators in the Plane.- 1. Introduction.- 2. Hypotheses and results.- 3. Preliminary results.- 4. Proof of the theorems.- References.- Solving a Special Class of Discrete Optimal Control Problems Via a Parallel Interior-Point Method.- 1. Introduction.- 2. Framework of the Method.- 3. Global convergence.- 4. A special class of discrete optimal control problems.- 5. Numerical experiments.- 6. Conclusions.- References.- Solving Large Scale Fixed Charge Network Flow Problems.- 1. Introduction.- 2. Problem Definition and Formulation.- 3. Solution Procedure.- 3.1. The DSSP.- 3.2. Local Search.- 4. Computational Results.- 5. Concluding Remarks.- References.- Variable Projection Methods for Large-Scale Quadratic Optimization in data Analysis Applications.- 1. Introduction.- 2. Large QP Problems in Training Support Vector Machines.- 3. Numerical Solution of Image Restoration Problem.- 4. A Bivariate Interpolation Problem.- 5. Conclusions.- References.- Strong solvability of boundary value problems in elasticity with Unilateral Constraints.- 1. Introduction.- 2. Basic assumptions and main results.- 3. Preliminary results.- 4. Proof of the theorems.- References.- Time Dependent Variational Inequalities -Order Derivatives.- 1. Introduction.- 2. Statement of the problem.- 3. An equivalent statement of the problem.- 4. Local minima.- 5. Properties of the function ?.- 5.1. A classical variation of z.- 5.2. The case z ? Z.- 5.3. The case z ? Z.- 6. Exact penalty functions.- 6.1. Properties of the function G.- 6.2. An Exact Penalty function.- 7. Necessary conditions for an Extremum.- References.- On the strong solvability of a unilateral boundary value problem for Nonlinear Parabolic Operators in the Plane.- 1. Introduction.- 2. Hypotheses and results.- 3. Preliminary results.- 4. Proof of the theorems.- References.- Solving a Special Class of Discrete Optimal Control Problems Via a Parallel Interior-Point Method.- 1. Introduction.- 2. Framework of the Method.- 3. Global convergence.- 4. A special class of discrete optimal control problems.- 5. Numerical experiments.- 6. Conclusions.- References.- Solving Large Scale Fixed Charge Network Flow Problems.- 1. Introduction.- 2. Problem Definition and Formulation.- 3. Solution Procedure.- 3.1. The DSSP.- 3.2. Local Search.- 4. Computational Results.- 5. Concluding Remarks.- References.- Variable Projection Methods for Large-Scale Quadratic Optimization in data Analysis Applications.- 1. Introduction.- 2. Large QP Problems in Training Support Vector Machines.- 3. Numerical Solution of Image Restoration Problem.- 4. A Bivariate Interpolation Problem.- 5. Conclusions.- References.- Strong solvability of boundary value problems in elasticity with Unilateral Constraints.- 1. Introduction.- 2. Basic assumptions and main results.- 3. Preliminary results.- 4. Proof of the theorems.- References.- Time Dependent Variational Inequalities - Some Recent Trends.- 1. Introduction.- 2. Time - an additional parameter in variational inequalities.- 2.1. Time-dependent variational inequalities and quasi-variational inequalities.- 2.2. Some classic results on the differentiability of the projection on closed convex subsets in Hilbert space.- 2.3. Time-dependent variational inequalities with memory terms.- 3. Ordinary Differential Inclusions with Convex Constraints: Sweeping Processes.- 3.1. Moving convex sets and systems with hysteresis.- 3.2. Sweeping processes and generalizations.- 4. Projected dynamical systems.- 4.1. Differentiability of the projection onto closed convex subsets revisited.- 4.2. Projected dynamical systems and stationarity.- 4.3. Well-posedness for projected dynamical systems.- 5. Some Asymptotic Results.- 5.1. Some classical results.- 5.2. An asymptotic result for full discretization.- 5.3. Some convergence results for continuous-time subgradient procedures for convex optimization.- References.- On the Contractibility of the Efficient and Weakly Efficient Sets in R2.- 1. Introduction.- 2. Preliminaries.- 3. Topological structure of the efficient sets of compact convex sets.- 4. Example.- References.- Existence Theorems for a Class of Variational Inequalities and Applications to a Continuous Model of Transportation.- 1. Introduction.- 2. Continuous transportation model.- 3. Existence Theorem.- References.- On Auxiliary Principle for Equilibrium Problems.- 1. Introduction.- 2. The auxiliary equilibrium problem.- 3. The auxiliary problem principle.- 4. Applications to variational inequalities and optimization problems.- 5. Concluding remarks.- References.- Multicriteria Spatial Price Networks: Statics and Dynamics.- 1. Introduction.- 2. The Multicriteria Spatial Price Model.- 3. Qualitative Properties.- 4. The Dynamics.- 5. The Discrete-Time Algorithm.- 6. Numerical Examples.- 7. Summary and Conclusions.- References.- Non regular data in unilateral variational problems.- 1. Introduction.- 2. The approach by truncation and approximation.- 3. Renormalized formulation.- 4. Multivalued operators and more general measures.- 5. Uniqueness and convergence.- References.- Equilibrium Concepts in Transportation Networks: Generalized Wardrop Conditions and Variational Formulations.- 1. Introduction.- 2. Equilibrium model in a traffic network.- References.- Variational Geometry and Equilibrium.- 1. Introduction.- 2. Variational Inequalities and Normals to Convex Sets.- 3. Quasi-Variational Inequalities and Normals to General Sets.- 4. Calculus and Solution Perturbations.- 5. Application to an Equilibrium Model with Aggregation.- References.- On the Calculation of Equilibrium in Time Dependent Traffic Networks.- 1. Introduction.- 2. Calculation of Equilibria.- 3. The algorithm.- 4. Applications and Examples.- 5. Conclusions.- References.- Mechanical Equilibrium and Equilibrium Systems.- 1. Introduction.- 2. Physical motivation.- 3. Statement of the mechanical force equilibrium problem.- 4. The principle of virtual work.- 5. Characterization of the constraints.- 6. Quasi-variational inequalities (QVI).- 7. Principle of virtual work in force fields under scleronomic and holonomic constraints.- 8. Dual form of the principle of virtual work in force field under scleronomic and holonomic constraints.- 9. Procedure for solving mechanical equilibrium problems.- 10. Existence of solutions.- References.- False Numerical Convergence in Some Generalized Newton Methods.- 1. Introduction.- 2. Some generalized Newton methods.- 3. False numerical convergence.- 4. An example.- 5. Avoiding false numerical convergence.- References.- Distance to the Solution Set of an Inequality with an Increasing Function.- 1. Introduction.- 2. Preliminaries.- 3. Distance to the solution set of the inequality with an arbitrary increasing function.- 4. Distance to the solution set of the inequality with an ICAR function.- 5. Inequalities with an increasing function defined on the entire space.- 6. Inequalities with a topical function.- References.- Transportation Networks with Capacity Constraints.- 1. Introduction.- 2. Wardrops generalized equilibrium condition.- 3. A triangular network.- 4. More about generalized equilibrium principle.- 5. Capacity constraints and paradox.- References.

Time-dependent traffic equilibria

We consider the existence, characterization, and calculation of equilibria in transportation networks, when the route capacities and demand requirements depend on time. The problem is situated in a Banach space setting and formulated in terms of a variational inequality.

General infinite dimensional duality and applications to evolutionary network equilibrium problems

In this paper the authors present an infinite dimensional duality theory for optimization problems and evolutionary variational inequalities where the constraint sets are given by inequalities and equalities. The difficulties arising from the structure of the constraint set are overcome by means of generalized constraint qualification assumptions based on the concept of quasi relative interior of a convex set. An application to a general evolutionary network model, which includes as special cases traffic, spatial price and financial equilibrium problems, concludes the paper.

The Internet, Evolutionary Variational Inequalities, and the Time-Dependent Braess Paradox

In this paper, we develop an evolutionary variational inequality model of the Internet with multiple classes of traffic and demonstrate its utility through the formulation and solution of a time-dependent Braess paradox. The model can handle time-dependent changes in demand as a consequence of developing news stories, following, for example, natural disasters or catastrophes or major media events. The model can also capture the time-varying demand for Internet resources during a regular weekday with its more regular rhythm of work and breaks. In addition, the model includes time-varying capacities on the route flows due to, for example, government interventions or network-type failures.

Double-layered dynamics: A unified theory of projected dynamical systems and evolutionary variational inequalities

In this paper we continue the study of the unified dynamics resulting from the theory of projected dynamical systems and evolutionary variational inequalities, initiated by Cojocaru, Daniele, and Nagurney. In the process we make explicit the interdependence between the two timeframes used in this new theory. The theoretical results presented here provide a natural context for studying applied problems in disciplines such as operations research, engineering, in particular, transportation science, as well as in economics and finance.

A variational inequality formulation of equilibrium models for end-of-life products with nonlinear constraints

Variational inequality theory facilitates the formulation of equilibrium problems in economic networks. Examples of successful applications include models of supply chains, financial networks, transportation networks, and electricity networks. Previous economic network equilibrium models that were formulated as variational inequalities only included linear constraints; in this case the equivalence between equilibrium problems and variational inequality problems is achieved with a standard procedure because of the linearity of the constraints. However, in reality, often nonlinear constraints can be observed in the context of economic networks. In this paper, we first highlight with an application from the context of reverse logistics why the introduction of nonlinear constraints is beneficial. We then show mathematical conditions, including a constraint qualification and convexity of the feasible set, which allow us to characterize the economic problem by using a variational inequality formulation. Then, we provide numerical examples that highlight the applicability of the model to real-world problems. The numerical examples provide specific insights related to the role of collection targets in achieving sustainability goals.

Time—Dependent Spatial Price Equilibrium Problem: Existence and Stability Results for the Quantity Formulation Model

This paper concerns with the study of the time–dependent variational inequality associated to the spatial price equilibrium model related to the quantity formulation. In particular existence the -orems of the solution to the associated variational inequality and a stability analysis of the equilibrium pattern is reported.

On Dynamical Equilibrium Problems and Variational Inequalities

We consider a time-dependent economic market in order to show the existence of time-dependent market equilibrium (which we call dynamic equilibrium). The model we are concerned with is the spatial price equilibrium model in the presence of excesses of supplies and of demands.

Variational approach for a general financial equilibrium problem: The Deficit Formula, the Balance Law and the Liability Formula. A path to the economy recovery

Without using a technical language, but using the universal language of mathematics, we provide simple but significant laws, as Deficit Formula, Balance Law and Liability Formula, for the management of the world economy. Decisions, under these laws, for the recovery of the economy and for the good governance clearly appear. Further a simple but useful economical indicator E(t) is provided and the results are illustrated with a significant example.

Projected Dynamical Systems, Evolutionary Variational Inequalities, Applications, and a Computational Procedure

In this paper, we establish the equivalence between the solutions to an evolutionary variational inequality and the critical points of a projected dynamical system in infinite–dimensional spaces. We then present an algorithm, with convergence results, for the computation of solutions to evolutionary variational inequalities based on a discretization method and with the aid of projected dynamical systems theory. A numerical traffic network example is given for illustrative purposes.