A family of sets H is ideal if the polyhedron {x ≥ 0 ∑i∈Sxi ≥ 1, VS H} is integral. Consider a graph G with vertices s,*** odd st-walk is either: an odd st-path;or the union of an even st-path and an odd circuit w...
详细信息
In this paper, we consider the classical scheduling problem on parallel machines with capacity constraints. We are given m identical machines, where each machine k can process up to ck jobs. the goal is to assign the...
详细信息
this paper addresses the culvert maintenance planning and scheduling problem faced by the Tennessee Department of Transportation (TDOT), withthe aim of optimizing the overall condition of culverts throughout Tennesse...
详细信息
this work proposes a new direction in structural design: the synthesis of structures through the reuse of elements. Reusing structural elements reduces the environmental impacts of building structures because it avoid...
详细信息
ISBN:
(纸本)9788412110104
this work proposes a new direction in structural design: the synthesis of structures through the reuse of elements. Reusing structural elements reduces the environmental impacts of building structures because it avoids sourcing new material, it reduces waste and it requires little energy. Designing structures from reused elements is unlike conventional structural design because stock element availability is a design input. In other words, structures must be designed to fit given element characteristics, e.g. cross-sections and lengths. Stock constraints such as number of elements and element lengths, have a major influence on the optimal structure layout and form. In this new paradigm structural form follows availability. this work formulates new computational methods for the synthesis of reticular structures through reuse. Two scenarios are presented: a) reuse of reclaimed elements from a given stock, and b) design of a common stock which is used as a kit-of-parts to build diverse structures. Case studies are presented to demonstrate the potential of the proposed methods. It is shown that structures produced by these methods have a significantly lower environmental impact than minimum weight structures made of new elements.
the proceedings contain 35 papers. the special focus in this conference is on combinatorialoptimization. the topics include: Online firefighting on trees;a multigraph formulation for the generalized minimum spanning ...
ISBN:
(纸本)9783319961507
the proceedings contain 35 papers. the special focus in this conference is on combinatorialoptimization. the topics include: Online firefighting on trees;a multigraph formulation for the generalized minimum spanning tree problem;the distance polytope for the vertex coloring problem;A PTAS for the time-invariant incremental knapsack problem;on bounded pitch inequalities for the min-knapsack polytope;Efficient algorithms for measuring the funnel-likeness of DAGs;jointly optimizing replica placement, requests distribution and server storage capacity on content distribution networks;an exact column generation-based algorithm for bi-objective vehicle routing problems;multi-start local search procedure for the maximum fire risk insured capital problem;Compact MILP formulations for the p-center problem;a branch-and-bound procedure for the robust cyclic job shop problem;an exact algorithm for the split-demand one-commodity pickup-and-delivery travelling salesman problem;descent with mutations applied to the linear ordering problem;characterization and approximation of strong general dual feasible functions;preemptively guessing the center;improved algorithms for k-domination and total k-domination in proper interval graphs;A heuristic for maximising energy efficiency in an OFDMA system subject to QoS constraints;an integerprogramming approach to the student-project allocation problem with preferences over projects;even flying cops should think ahead;a generalization of the minimum branch vertices spanning tree problem;the next release problem: Complexity, exact algorithms and computations;a polyhedral view to generalized multiple domination and limited packing;alternating current optimal power flow with generator selection;parameterized algorithms for module map problems;2 CSPs all are approximable within a constant differential factor.
Following the seminal work of Padberg on the Boolean quadric polytope BQP and its LP relaxation BQPLP, we consider a natural extension: the polytopes SATP and SATPLP, with BQPLP being a projection of SATPLP face (and ...
详细信息
Small- and medium-sized enterprises (SMEs) represent 70% of employment and contribute to 25% of the GDP in Ecuador’s economy. Since SMEs depend heavily on efficiently managing their economic resources to maintain com...
详细信息
Scheduling problems in which agents (users, customers, application masters, resource manager, etc.) have to share the same set(s) of resources are at the frontier of combinatorialoptimization and cooperative game the...
详细信息
ISBN:
(纸本)9783319480572;9783319480565
Scheduling problems in which agents (users, customers, application masters, resource manager, etc.) have to share the same set(s) of resources are at the frontier of combinatorialoptimization and cooperative game theory. this paper deals with scheduling problems arising when two agents, each with a set of nonpreemptive jobs, compete to perform their respective jobs on two common identical parallel machines. Each agent aims at minimizing a certain objective function that depends on the completion times of its jobs only. the objective functions we consider in our study are makespan and number of tardy jobs. the agents may share some jobs and this problem is called non-disjoint multi-agent scheduling problem [3]. Finding the optimal solution for one agent with a constraint on the other agent's cost function is known to be NP-hard. To obtain best compromise solutions for each agent, we propose polynomial and pseudo-polynomial heuristics. Two mixed integer linear programming models are developed to calculate exact non-dominated solutions. Experimental results are conducted to measure the solutions quality given by heuristics.
In many signal processing and data mining applications, we need to approximate a given matrix Y with a low-rank product Ya parts per thousand AX. Both matrices A and X are to be determined, but we assume that from the...
详细信息
In many signal processing and data mining applications, we need to approximate a given matrix Y with a low-rank product Ya parts per thousand AX. Both matrices A and X are to be determined, but we assume that from the specifics of the application we have an important piece of a-priori knowledge: A must have zeros at certain positions. In general, different AX factorizations approximate a given Y equally well, so a fundamental question is whether the known zero pattern of A contributes to the uniqueness of the factorization. Using the notion of structural rank, we present a combinatorial characterization of uniqueness up to diagonal scaling (subject to a mild non-degeneracy condition on the factors), called structural identifiability of the model. Next, we define an optimization problem that arises in the need for efficient experimental design. In this context, Y contains sensor measurements over several time samples, X contains source signals over time samples and A contains the source-sensor mixing coefficients. Our task is to monitor the signal sources withthe cheapest subset of sensors, while maintaining structural identifiability. Firstly, we show that this problem is NP-hard. Secondly, we present a mixed integer linear program for its exact solution together with two practical incremental approaches. We also propose a greedy approximation algorithm. Finally, we perform computational experiments on simulated problem instances of various sizes.
this paper proposes a mathematical model to handle emergency service requests in electric power distribution utilities. Given available maintenance crews and their already assigned service orders, a mathematical model...
详细信息
暂无评论