A new bottom-up search method for determining all maximal efficient faces in multiple objective linear programming

Categories Multi-Criteria Optimization

Bottom-up search methods for determining the efficient set of a multiple objective linear programming (MOLP) problem have a valuable advantage that they can quickly give efficient subsets of the MOLP problem to the decision makers. Main difficulties of the previously appeared bottom-up search methods are finding all efficient extreme points adjacent to and enumerating all … Read more

A NEW PARTIAL SAMPLE AVERAGE APPROXIMATION METHOD FOR CHANCE CONSTRAINED PROBLEM

Categories Stochastic Programming Tags , ,

In this paper, we present a new scheme of a sampling method to solve chance constrained programs. First of all, a modified sample average approximation, namely Partial Sample Average Approximation (PSAA) is presented. The main advantage of our approach is that the PSAA problem has only continuous variables whilst the standard sample average approximation (SAA) … Read more

Totally Unimodular Multistage Stochastic Programs

Categories Stochastic Programming

We consider totally unimodular multistage stochastic programs, that is, multistage stochastic programs whose extensive-form constraint matrices are totally unimodular. We establish several sufficient conditions and identify examples that have arisen in the literature. CitationRuichen (Richard) Sun, Oleg V. Shylo, Andrew J. Schaefer, Totally unimodular multistage stochastic programs, Operations Research Letters, Volume 43, Issue 1, January … Read more

The Multi-Hour Bandwidth Packing Problem with Queuing Delays: Bounds and Exact Solution Approach

Categories Applications - OR and Management Sciences Tags , , , , , , ,

The multi-hour bandwidth packing problem arises in telecommunication networks that span several time horizon. The problem seeks to select and route a set of messages from a given list of messages with prespecified requirement on demand for bandwidth under time varying traffic conditions on an undirected communication network such that the total profit is maximized. … Read more

Machine Learning and Portfolio Optimization

Categories Applications - OR and Management Sciences, Finance and Economics Tags , , , ,

The portfolio optimization model has limited impact in practice due to estimation issues when applied with real data. To address this, we adapt two machine learning methods, regularization and cross-validation, for portfolio optimization. First, we introduce performance-based regularization (PBR), where the idea is to constrain the sample variances of the estimated portfolio risk and return, … Read more

On Truck dock assignment problem with operational time constraint within cross docks

Categories Applications - OR and Management Sciences, Combinatorial Optimization, Transportation

An integer programming model for the truck dock assignment problem with operational time constraint within cross docks has been proposed in (Miao, Z.,Lim, A.,Ma, H., 2009. Truck dock assignment problem with operational time constraint within crossdocks. European Journal of Operational Research 192 (1), 105–115). We address the following issues in this formulation: 1) from among … Read more

HIPAD – A Hybrid Interior-Point Alternating Direction algorithm for knowledge-based SVM and feature selection

Categories Convex and Nonsmooth Optimization, Data-Mining, Quadratic Programming Tags , , , ,

We consider classification tasks in the regime of scarce labeled training data in high dimensional feature space, where specific expert knowledge is also available. We propose a new hybrid optimization algorithm that solves the elastic-net support vector machine (SVM) through an alternating direction method of multipliers in the first phase, followed by an interior-point method … Read more

p-facility Huff location problem on networks

Categories Applications - OR and Management Sciences, Network Optimization Tags , , , , ,

The p-facility Huff location problem aims at locating facilities on a competitive environment so as to maximize the market share. While it has been deeply studied in the field of continuous location, in this paper we study the p-facility Huff location problem on networks formulated as a Mixed Integer Nonlinear Programming problem that can be … Read more

Light on the Infinite Group Relaxation

Categories (Mixed) Integer Linear Programming, Branch and Cut Algorithms, Cutting Plane Approaches

This is a survey on the infinite group problem, an infinite-dimensional relaxation of integer linear optimization problems introduced by Ralph Gomory and Ellis Johnson in their groundbreaking papers titled “Some continuous functions related to corner polyhedra I, II” [Math. Programming 3 (1972), 23-85, 359-389]. The survey presents the infinite group problem in the modern context … Read more

Semi-definite relaxations for optimal control problems with oscillation and concentration effects

Categories Control Applications, Semi-definite Programming

Converging hierarchies of finite-dimensional semi-definite relaxations have been proposed for state-constrained optimal control problems featuring oscillation phenomena, by relaxing controls as Young measures. These semi-definite relaxations were later on extended to optimal control problems depending linearly on the control input and typically featuring concentration phenomena, interpreting the control as a measure of time with a … Read more