Integrated Mode Choice and Dynamic Traveler Assignment in Multimodal Transit Networks: Mathematical Formulation, Solution Procedure, and Large-Scale Application

2016 ◽  
Vol 2564 (1) ◽  
pp. 78-88 ◽  
Author(s):  
İ. Ömer Verbas ◽  
Hani S. Mahmassani ◽  
Michael F. Hyland ◽  
Hooram Halat
Keyword(s):  
Large Scale ◽  
Mode Choice ◽  
Mathematical Formulation ◽  
Solution Procedure ◽  
Transit Networks

Bilateral bidding strategy in joint day-ahead energy and reserve electricity markets considering techno-economic-environmental measures

2021 ◽  
pp. 0958305X2110148
Author(s):  
Mojtaba Shivaie ◽  
Mohammad Kiani-Moghaddam ◽  
Philip D Weinsier
Keyword(s):  
Electricity Market ◽  
Large Scale ◽  
Search Algorithm ◽  
Power Grid ◽  
Mathematical Formulation ◽  
Test System ◽  
Bidding Strategy ◽  
Level Problem ◽  
Optimal Bidding ◽  
Environmental Measures

In this study, a new bilateral equilibrium model was developed for the optimal bidding strategy of both price-taker generation companies (GenCos) and distribution companies (DisCos) that participate in a joint day-ahead energy and reserve electricity market. This model, from a new perspective, simultaneously takes into account such techno-economic-environmental measures as market power, security constraints, and environmental and loss considerations. The mathematical formulation of this new model, therefore, falls into a nonlinear, two-level optimization problem. The upper-level problem maximizes the quadratic profit functions of the GenCos and DisCos under incomplete information and passes the obtained optimal bidding strategies to the lower-level problem that clears a joint day-ahead energy and reserve electricity market. A locational marginal pricing mechanism was also considered for settling the electricity market. To solve this newly developed model, a competent multi-computational-stage, multi-dimensional, multiple-homogeneous enhanced melody search algorithm (MMM-EMSA), referred to as a symphony orchestra search algorithm (SOSA), was employed. Case studies using the IEEE 118-bus test system—a part of the American electrical power grid in the Midwestern U.S.—are provided in this paper in order to illustrate the effectiveness and capability of the model on a large-scale power grid. According to the simulation results, several conclusions can be drawn when comparing the unilateral bidding strategy: the competition among GenCos and DisCos facilitates; the improved performance of the electricity market; mitigation of the polluting atmospheric emission levels; and, the increase in total profits of the GenCos and DisCos.

A New Memetic Approach to Solve the Strategic Berth Template Problem

2021 ◽  
Vol 12 (3) ◽  
pp. 212-231
Author(s):  
Issam El Hammouti ◽  
Azza Lajjam ◽  
Mohamed El Merouani
Keyword(s):  
Large Scale ◽  
Container Terminal ◽  
Mathematical Formulation ◽  
Population Based ◽  
Allocation Problem ◽  
Computational Time ◽  
Berth Allocation ◽  
Berth Allocation Problem ◽  
Simulating Annealing ◽  
Annealing Algorithm

The berth allocation problem is one of the main concerns of port operators at a container terminal. In this paper, the authors study the berth allocation problem at the strategic level commonly known as the strategic berth template problem (SBTP). This problem aims to find the best berth template for a set of calling ships accepted to be served at the port. At strategic level, port operator can reject some ships to be served for avoid congestion. Since the computational complexity of the mathematical formulation proposed for SBTP, solution approaches presented so far for the problem are limited especially at level of large-scale instances. In order to find high quality solutions with a short computational time, this work proposes a population based memetic algorithm which combine a first-come-first-served (FCFS) technique, two genetics operators, and a simulating annealing algorithm. Different computational experiences and comparisons against the best known solutions so far have been presented to show the performance and effectiveness of the proposed method.

A Scalable Time-Parallel Solution of Periodic Rotor Dynamics in X3D

2021 ◽  
Author(s):  
Mrinalgouda Patil ◽  
Anubhav Datta
Keyword(s):  
Harmonic Balance ◽  
Large Scale ◽  
Structural Model ◽  
Three Dimensional ◽  
Harmonic Balance Method ◽  
Flight Test ◽  
Solution Procedure ◽  
Balance Method ◽  
Computational Time ◽  
Near Resonance

A time-parallel algorithm is developed for large-scale three-dimensional rotor dynamic analysis. A modified harmonic balance method with a scalable skyline solver forms the kernel of this algorithm. The algorithm is equipped with a solution procedure suitable for large-scale structures that have lightly damped modes near resonance. The algorithm is integrated in X3D, implemented on a hybrid shared and distributed memory architecture, and demonstrated on a three-dimensional structural model of a UH-60A-like fully articulated rotor. Flight-test data from UH-60A Airloads Program transition flight C8513 are used for validation. The key conclusion is that the new solver converges to the time marching solution more than 50 times faster and achieves a performance greater than 1 teraFLOPS. The significance of this conclusion is that the principal barrier of computational time for trim solution using high-fidelity three-dimensional structures can be overcome with the scalable harmonic balance method demonstrated in this paper.

Short-term management of hydropower reservoirs under meteorological uncertainty by means of multi-stage optimization

2015 ◽  
Vol 63 (7) ◽  
Author(s):  
Steffi Naumann ◽  
Dirk Schwanenberg ◽  
Divas Karimanzira ◽  
Fernando Fan ◽  
Christopher Allen
Keyword(s):  
Management System ◽  
Large Scale ◽  
Mathematical Formulation ◽  
Stochastic Approach ◽  
Army Corps ◽  
Test Case ◽  
Optimization Approach ◽  
Renewable Energy Resources ◽  
Short Term ◽  
Multi Stage

AbstractUncertainty in meteorology, market volatility and balancing requirements for introducing renewable energy resources into the power grid, environmental obligations require robust management of non-intermittent energy sources such as hydropower. In this paper, a probalistic management system is shown and its performance is discussed in relation to the deterministic one. In the system, scenario trees enable to setup a multi-stage stochastic optimization approach as the mathematical formulation of the short-term system management. The Federal Columbia River Power System (FCRPS), managed by the Bonneville Power Administration, the US Army Corps of Engineers and the Bureau of Reclamation, serves as a large-scale test case for the application of the management system and proves that the stochastic approach is feasible and verify the operational applicability within a real-time environment.

scholarly journals An Efficient 3-D FNPF Numerical Wave Tank for Virtual Large-Scale Wave Basin Experiment

2012 ◽  
Author(s):  
Seshu Nimmala ◽  
Solomon Yim ◽  
Stephan Grilli
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Mathematical Formulation ◽  
Three Dimensional ◽  
Numerical Wave Tank ◽  
Wave Tank ◽  
Wave Basin ◽  
Nonlinear Potential ◽  
Numerical Wave ◽  
Computing Platforms

This paper presents an accurate and efficient three-dimensional computational model (3D numerical wave tank), based on fully nonlinear potential flow (FNPF) theory, and its extension to incorporate the motion of a laboratory snake piston wavemaker, to simulate experiments in a large-scale 3D wave basin (i.e. to conduct “virtual” or numerical experiments). The code is based on a higher-order boundary element method combined with a Fast Multipole Algorithm (FMA). Particular efforts were devoted to making the code efficient for large-scale simulations using high-performance computing platforms to complement experimental 3D wave basins. The numerical simulation capability can serve as an optimization tool at the experimental planning and detailed design stages. To date, waves that can be generated in the NWT include solitary, Cnoidal, and Airy waves. In this paper, we detail the model, mathematical formulation, and wave generation. Experimental or analytical comparisons with NWT results are provided for several cases to assess the accuracy and applicability of the numerical model to practical engineering problems.

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