This paper presents a millisecond-level look-ahead control algorithm for energy storage. The algorithm connects the optimal control with the Lagrangian multiplier associated with the state-of-charge constraint. It is ...
详细信息
ISBN:
(纸本)9781538682661
This paper presents a millisecond-level look-ahead control algorithm for energy storage. The algorithm connects the optimal control with the Lagrangian multiplier associated with the state-of-charge constraint. It is compared to solving look-ahead control using a state-of-the-art convex optimization solver. The paper include discussions on sufficient conditions for including the non-convex simultaneous charging and discharging constraint, and provide upper and lower bounds for the primal and dual results under such conditions. Simulation results show that both methods obtain the same control result, while the proposed algorithm runs up to 100,000 times faster and solves most problems within one millisecond. The theoretical results from developing this algorithm also provide key insights into designing optimal energy storage control schemes at the centralized system level as well as under distributed settings.
The paper deals with the development of a mathematical model of aerosol fine particles transport and diffusion in the atmosphere in spherical coordinates. This approach allows us to shorten the calculation time and in...
详细信息
ISBN:
(纸本)9783030169626;9783030169619
The paper deals with the development of a mathematical model of aerosol fine particles transport and diffusion in the atmosphere in spherical coordinates. This approach allows us to shorten the calculation time and increase the order of approximation with respect to spatial variables. For the numerical solution of the problem, a computational algorithm based on the “straight-line method” was proposed. This algorithm allows us to reduce the multidimensional problem in the form of a partial differential equation to an ordinary differential equation with the corresponding initial and boundary conditions. Based on the developed mathematical support, the main parameters that significantly influenced the process of transporting aerosol fine particles, as well as the rate of their deposition, were investigated. The obtained results can be successfully used as software in the optimal allocation of newly designed facilities in industrial regions, as well as to assess the scale and geography of emissions spread to the environment, to estimate the concentration of harmful substances in the atmosphere and on the underlying surface with subsequent decision making to minimize ecological risks.
Matrix multiplication (GEMM) is a core operation to numerous scientific applications. Traditional implementations of Strassen-like fast matrix multiplication (FMM) algorithms often do not perform well except for very ...
详细信息
ISBN:
(纸本)9781538639146
Matrix multiplication (GEMM) is a core operation to numerous scientific applications. Traditional implementations of Strassen-like fast matrix multiplication (FMM) algorithms often do not perform well except for very large matrix sizes, due to the increased cost of memory movement, which is particularly noticeable for non-square matrices. Such implementations also require considerable workspace and modifications to the standard BLAS interface. We propose a code generator framework to automatically implement a large family of FMM algorithms suitable for multiplications of arbitrary matrix sizes and shapes. By representing FMM with a triple of matrices [U, V, W] that capture the linear combinations of submatrices that are formed, we can use the Kronecker product to define a multi-level representation of Strassen-like algorithms. Incorporating the matrix additions that must be performed for Strassen-like algorithms into the inherent packing and micro-kernel operations inside GEMM avoids extra workspace and reduces the cost of memory movement. Adopting the same loop structures as high-performance GEMM implementations allows parallelization of all FMM algorithms with simple but efficient data parallelism without the overhead of task parallelism. We present a simple performance model for general FMM algorithms and compare actual performance of 20+ FMM algorithms to modeled predictions. Our implementations demonstrate a performance benefit over conventional GEMM on single core and multi-core systems. This study shows that Strassen-like fast matrix multiplication can be incorporated into libraries for practical use.
Let us consider a function {Mathematical expression} where the functions fij(z) are supposed to be continuously differentiable and real-valued on a set Ω of En, z∂En. The problem is to find maxze{open}Ωφ{symbol}(z)...
详细信息
Simulating the steam Injection process of pressurized decompression tanks is a challenging engineering problem due to the large amount of computational resource requirements and its complex physical model. This study ...
详细信息
ISBN:
(纸本)9781728109459
Simulating the steam Injection process of pressurized decompression tanks is a challenging engineering problem due to the large amount of computational resource requirements and its complex physical model. This study is a necessary algorithmic study to perform a 3D numerical simulation from the PRT (Pressurizer Relief Tank) to the transient dumping process in a chamber containing a tank. Parallel simulation was performed by the open source CFD tool OpenFOAM based on the numerical algorithm we discussed. The results show that the simulation results are in accordance with the basic physical laws, and the results reflect the pressure and temperature of the entire pressure relief tank in detail, which can provide guidance for the safe design of the reactor coolant system.
We present a nonparametric method for fitting the term structure of interest rates from bond prices. Our method is a variant of the smoothing spline approach, but within our framework we are able to determine the smoo...
详细信息
We present a nonparametric method for fitting the term structure of interest rates from bond prices. Our method is a variant of the smoothing spline approach, but within our framework we are able to determine the smoothing coefficient automatically from data using the generalized cross-validation or maximum likelihood estimates. We present an effective numerical algorithm to simultaneously find the term structure and the optimal smoothing coefficient. Finally, we compare the proposed nonparametric fitting method with other parametric and nonparametric methods to find its superior performance. We find that existing term structure fitting methods perform well in liquid markets while illiquid markets present new challenges, which we address in this article.
We present an algorithm that uses linear programming to parameterize continuous and piecewise affine Lyapunov functions for switched systems. The novel feature of the algorithm is, that it can compute Lyapunov functio...
详细信息
ISBN:
(纸本)9789897584428
We present an algorithm that uses linear programming to parameterize continuous and piecewise affine Lyapunov functions for switched systems. The novel feature of the algorithm is, that it can compute Lyapunov functions for switched system with a strongly asymptotically stable equilibrium, for which the equilibrium of the corresponding differential inclusion is merely weakly asymptotically stable. For the differential inclusion no such Lyapunov function exists. This is achieved by removing constraints from a linear programming problem of an earlier algorithm to compute Lyapunov functions, that are not necessary to assert strong stability for the switched system. We demonstrate the benefits of this new algorithm sing Artstein's circles as an example.
A multipole expansion of the fundamental solution of the fractional power of the Laplace operator is constructed in terms of the Gegenbauer polynomials. Based on the decomposition constructed and the idea of the fast ...
详细信息
A new method for calculating the radial spheroidal functions of the first kind is proposed for the arguments that are greater than unity in modulus. A well-known representation of these functions is refined and used f...
详细信息
General-purpose graphics processing units (GPGPUs) could bring huge performance improvements in scientific and numerical fields. We presented two approaches utilizing hybrid CPU/GPU system in Cholesky factorization. F...
详细信息
ISBN:
(纸本)9781467392952
General-purpose graphics processing units (GPGPUs) could bring huge performance improvements in scientific and numerical fields. We presented two approaches utilizing hybrid CPU/GPU system in Cholesky factorization. First, we analyzed the implementation of Cholesky factorization in MAGMA and identified the bottleneck of the current implementation, which is the use of fixed block size without considering any factors in the computing environment. So, we designed an algorithm, which could determine the optimal block size of Cholesky factorization based on multiple factors (input matrix size, CPU/GPU performance, and CPU/GPU bandwidth, etc.). Then, we presented a new improvement on MAGMA's implementation utilize the algorithm. Test results showed that our approach is more efficient than MAGMA's fixed block size implementation under some circumstance. After combining our implementation with MAGMA's implementation, the new hybrid implementation could outperform the current MAGMA implementation. Second, we identified that all the implementations of Cholesky factorization, to our best knowledge, that utilized the GPU do not fully utilized the multicore CPU. So, after studied other researchers approaches, we designed a new algorithm that could utilize multicore CPU and GPU simultaneously in Cholesky factorization. Our approach could keep the block size and workload distribution between CPU and GPU dynamically. Testing results showed the optimal data distribution ratio for our current implementation.
暂无评论