This study investigates the potential accuracy boundaries of physics-informed neural networks, contrasting their approach with previous similar works and traditional numerical methods. We find that selecting improved ...
详细信息
This study investigates the potential accuracy boundaries of physics-informed neural networks, contrasting their approach with previous similar works and traditional numerical methods. We find that selecting improved optimization algorithms significantly enhances the accuracy of the results. Simple modifications to the loss function may also improve precision, offering an additional avenue for enhancement. Despite optimization algorithms having a greater impact on convergence than adjustments to the loss function, practical considerations often favor tweaking the latter due to ease of implementation. On a global scale, the integration of an enhanced optimizer and a marginally adjusted loss function enables a reduction in the loss function by several orders of magnitude across diverse physical problems. Consequently, our results obtained using compact networks (typically comprising 2 or 3 layers of 20-30 neurons) achieve accuracies comparable to finite difference schemes employing thousands of grid points. This study encourages the continued advancement of PINNs and associated optimization techniques for broader applications across various fields.
The quantum approximate optimization algorithm (QAOA) is one of the canonical algorithms designed to find approximate solutions for combinatorial optimization problems on current noisy intermediate-scale quantum (NISQ...
详细信息
The quantum approximate optimization algorithm (QAOA) is one of the canonical algorithms designed to find approximate solutions for combinatorial optimization problems on current noisy intermediate-scale quantum (NISQ) devices. The primary focus of ongoing research is to exhibit its speed advantage over classical algorithms. However, the performance of QAOA is restricted at lower depths, while higher depths are limited by current experimental techniques. We propose an algorithm that amalgamates the capabilities of QAOA and the real-space renormalization group transformation. Numerical simulations indicate that our proposed algorithm can deliver precise solutions for specific randomly generated instances using QAOA at shallow depths, even at the lowest depth. This algorithm is particularly suitable for current NISQ devices, offering the potential to demonstrate a quantum advantage.
The urban heat island (UHI) effect significantly impacts building energy consumption, but its effect on energy retrofit potential remains unclear. Here, we propose a data-driven surrogate optimization framework to ass...
详细信息
The urban heat island (UHI) effect significantly impacts building energy consumption, but its effect on energy retrofit potential remains unclear. Here, we propose a data-driven surrogate optimization framework to assess the energy-saving potential of improving building envelope thermal performance in 101 public buildings in Shenzhen. The framework integrates batch building energy modeling, ensemble learning surrogate model training, and multi-objective optimization. The potential changes in building loads resulting from different parameter combinations are defined as energy-saving potential. We use the Urban Weather Generator to adjust typical meteorological year data and account for UHI effects in energy modeling. The results indicate that neglecting the UHI effect in Shenzhen overestimates the potential for building energy retrofitting by approximately 25.2 % (office buildings:-8.96 %, commercial buildings: 60.7 %). Among the nine thermal retrofitting parameters, the heat transfer coefficient of windows contributes the most to the energy-saving potential. Considering the UHI effect or not leads to significant differences in retrofitting strategies and optimal retrofitting parameter configurations. These findings underscore the importance of considering the UHI effect and interactions between buildings in energy retrofit modeling and decision-making processes to formulate precise retrofit strategies and schemes.
Anaerobic digestion (AD) is an important technology that can be engaged to produce renewable energy and valuable products from organic waste while reducing the net greenhouse gas emissions. Due to the AD process compl...
详细信息
Anaerobic digestion (AD) is an important technology that can be engaged to produce renewable energy and valuable products from organic waste while reducing the net greenhouse gas emissions. Due to the AD process complexity, further development of AD technology goes hand in hand with the advancement of underlying mathematical models and optimization techniques. This paper presents a comprehensive and critical review of current AD process modeling and optimization techniques as well as various aspects of further processing of AD products. The most important mechanistically inspired, kinetic, and phenomenological AD models and the most frequently used deterministic and stochastic methods for AD process optimization are addressed. The foundations, properties, and features of these models and methods are highlighted, discussed, and compared with respect to advantages, disadvantages, and various performance metrics;the models are also ranked with respect to adequately introduced criteria. Since AD process optimization affects heavily the required treatment and utilization of AD products, biogas and digestate utilization in the production of renewable energy and other valuable products is also addressed. Furthermore, special attention is devoted to the challenges and future research needs related to AD modeling and optimization, such are modeling issues related to foaming and microbial activities, AD model parameters calibration, CFD simulation challenges, availability of experimental data, and optimization of the AD process with respect to further biogas and digestate utilizations. As current research results indicate, further progress in these areas could notably improve AD modeling robustness and accuracy as well as AD optimization performance.
Virtual power plant (VPP) with a high percentage of flexibility resources has issues that need to be addressed, such as high source-load volatility and limited scope to participate in multi-market bids. Therefore, thi...
详细信息
Virtual power plant (VPP) with a high percentage of flexibility resources has issues that need to be addressed, such as high source-load volatility and limited scope to participate in multi-market bids. Therefore, this paper proposes a VPP standby capacity setting method based on normal distribution framework and Bayesian parameter optimization. Through the marginal revenue and expenditure of standby capacity analysis, this paper constructs a two-stage optimization strategy for VPP trading in multi-market considering double uncertainty, which is solved by the Improved Multi-Objective Squirrel Search Algorithm (IMSSA). Compared to the traditional program, the VPP's participation in the day-ahead spot bidding increased by 5.97% and 2.48%, respectively, total revenue increased by 17.41% and 12.97%, respectively, reliability increased by 0.21%, and overall energy efficiency increased by 10%. Compared to Squirrel Search Algorithm and Particle Swarm optimization Algorithm, IMSSA improves the optimal revenue by 1.03% and 1.91%, and the convergence speed by 24.24% and 38.01%, respectively.
The Kepler optimization algorithm (KOA) is a recently proposed physics-based algorithm inspired by Kepler's laws. Despite the strong competitiveness of KOA relative to established algorithms, it faces challenges s...
详细信息
As the main energy consumption part of the central air-conditioning systems, the energy saving of the chilled water system is particularly crucial. This system realizes heat exchange with indoor air by delivering chil...
详细信息
As the main energy consumption part of the central air-conditioning systems, the energy saving of the chilled water system is particularly crucial. This system realizes heat exchange with indoor air by delivering chilled water to air-conditioning units, effectively regulating indoor temperature and humidity to ensure thermal comfort. In this article, an improved multi-objective coati optimization algorithm (IMOCOA) is used to optimize the operating parameters and thermal comfort environment parameters of chilled water systems to improve thermal comfort and reduce energy consumption. The algorithm introduces chaotic mapping to enhance search diversity, balances global and local search capabilities through Levy flight and Gauss variation strategies, and uses location greedy choices to help coatis jump out of local optima. To verify the optimization effect of IMOCOA, a multi-objective optimization model was established, combining the energy consumption model of the chilled water system and the simplified thermal comfort model. Key parameters, including chilled water supply temperature, pump speed ratio, indoor temperature, and relative humidity, are optimized. The simulation results from the experiments show that the average energy-saving rate of the chilled water system using IMOCOA is 7.8% and thermal comfort is improved by 19.6%. Compared to other optimization algorithms, this method demonstrates a better optimization effect.
This paper introduces a Julia package for tackling linear Diophantine systems and related optimization problems using the Polyhedral Omega algorithm. The package integrates partition analysis and polyhedral geometry t...
详细信息
Under the influence of network popularization, the information dissemination speed of online public opinion is faster, and public opinion events appear more frequently. It is necessary to effectively monitor them. Thi...
详细信息
This paper delves into the investigation of a distributed aggregative optimization problem within a network. In this scenario, each agent possesses its own local cost function, which relies not only on the local state...
详细信息
暂无评论