Generalized Model and Deep Reinforcement Learning-Based Evolutionary Method for Multitype Satellite Observation Scheduling

Multitype satellite observation, including optical observation satellites, synthetic aperture radar (SAR) satellites, and electromagnetic satellites, has become an important direction in integrated satellite applications due to its ability to cope with various complex situations. In the multitype satellite observation scheduling problem ...

How can the behaviour of specialized heuristic solvers assist constraint solvers for optimization problems: A lookahead approach for Chuffed that emulates the behaviour of heuristic solvers

<br/>Constraint programming solvers provide a generalizable approach to finding solutions for optimization problems. However, when comparing the performance of constraint programming solvers to the performance of a heuristic solver for an optimization problem such as cluster editing, the heuristic solver is able to find near-optimal and optimal...

Controller Placement with Optimal Availability

The controller placement problem concerns the placement of controllers on Software-Defined Networks such that a pre-defined objective is optimized. In this thesis, we conduct research on the controller placement problem with network availability as the performance metric. Unlike other approximate evaluations, we compute the exact value with the...

Greedy optimization of resistance-based graph robustness with global and local edge insertions

The total effective resistance, also called the Kirchhoff index, provides a robustness measure for a graph G. We consider two optimization problems of adding k new edges to G such that the resulting graph has minimal total effective resistance (i.e., is most robust)—one where the new edges can be anywhere in the graph and one where the new...

Integer Programming Models for the Class Constrained Multi-Level Bin Packing Problem

The Multi-Level Bin Packing problem is a generalisation of the widely-known NP-hard Bin Packing problem. This work aims to investigate approaching this problem, as well as a version including Class Constraints, through integer programming. By modelling the problems in two ways: standard, and with a network flow approach. The studying of the...

Optimal Commutation for Switched Reluctance Motors using Gaussian Process Regression

Switched reluctance motors are appealing because they are inexpensive in both construction and maintenance. The aim of this paper is to develop a commutation function that linearizes the nonlinear motor dynamics in such a way that the torque ripple is reduced. To this end, a convex optimization problem is posed that directly penalizes torque...

Heuristic-Based Approach for Near-Optimal Response to Water Distribution Network Failures in Near Real Time

This paper proposes a new method to identify the near-optimal response to failures in water distribution networks in near real time. The response method is formulated as a two-objective optimization problem with objectives being the minimization of failure impacts and related operational costs. The new heuristics-based method is developed and...

Mathematical models for simulation and optimization of multi-carrier energy systems

Energy systems are vital in modern society, and reliable operation is crucial. Multi-carrier energy systems (MESs), which couple two or more single-carrier systems, have recently become more important, as the need for sustainable energy systems increases. Important tools for the design and operation of energy systems are steady-state simulation...

A Techno-Economical Analysis of Hydrogen as Long-Term Storage Medium in the Netherlands: How long-term hydrogen storage helps to achieve energy security in an energy system dominated by variable renewable energy sources

The integration of Variable Renewable Energy Sources (VRES) creates challenges for meeting load demand. The lack of on-demand power generation of these VRES effectively threatens energy security. Therefore, storage facilities, especially hydrogen, have been broadly researched for potential implementation in our energy system, enabling on-demand...

Optimal flow for general multi-carrier energy systems, including load flow equations

Optimization is an important tool for the operation of an energy system. Multi-carrier energy systems (MESs) have recently become more important. Load flow (LF) equations are used within optimization to determine if physical network limits are violated. Due to nonlinearities, the solvability of the OF problem and the convergence of the...

Simplified Quadratic Optimization based IPMSM Full-Speed Range Rotor Position Estimation in Synchronous Rotating Frame

This article proposes a rotor position and speed estimation method for the interior permanent magnet synchronous machine (IPMSM) in the full-speed range. The proposed method is implemented in the synchronous rotating frame. Based on the voltage equation of the IPMSM in the synchronous rotating frame, a single-variable optimization problem is...

On Some Optimization Problems that Can Be Solved in O(n) Time

We consider nine elementary problems in optimization. We simply explore the conditions for optimality as known from the duality theory for convex optimization. This yields a quite straightforward solution method for each of these problems. The main contribution of this paper is that we show that even in the harder cases the solution needs...

Dynamic and interactive re-formulation of multi-objective optimization problems for conceptual architectural design exploration

Simulation-Based Multi-Objective Optimization (SBMOO) methods are being increasingly used in conceptual architectural design. They mostly focus on the solving, rather than the re-formulation, of a Multi-Objective Optimization (MOO) problem. However, Optimization Problem Re-Formulation (Re-OPF) is necessary for treating ill-defined conceptual...

Multi-disciplinary and multi-objective optimization problem re-formulation in computational design exploration: A case of conceptual sports building design

The benefits of applying multi-objective optimization (MOO) in building design have been increasingly recognized in recent decades. The existing or traditional computational design optimization (CDO) approaches mostly focus on optimization problem solving (OPS), as they often conduct optimizations directly by assuming the optimization...

An approach for estimating time-variable rates from geodetic time series

There has been considerable research in the literature focused on computing and forecasting sea-level changes in terms of constant trends or rates. The Antarctic ice sheet is one of the main contributors to sea-level change with highly uncertain rates of glacial thinning and accumulation. Geodetic observing systems such as the Gravity Recovery...

Application of Finite Volume and Finite Element methods to distributed optimal control of semi-linear elliptic equations

In this paper we are concerned with distributed optimal control problems governed by a second-order linear and semi-linear elliptic partial differential equations (PDE), where the control is distributed on the domain ?. The semi-linear elliptic boundary value problem is analysed by proving the existence of a unique solution and optimal control...

Fast solvers for concentrated elastic contact problems

Rail transportation plays an important role in our everyday life, and there is fast development and modernization in the railway industry to meet the growing demand for swifter, safer and more comfortable trains. At the same time, the security of train operation and the maintenance of rails have to be considered. A lot of research on these...