linear programming optimization is central to engineering designs, logistics management, and decision-making in every sector of the economy. Traditional hardware using CPU and GPU platforms for this purpose is severel...
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linear programming optimization is central to engineering designs, logistics management, and decision-making in every sector of the economy. Traditional hardware using CPU and GPU platforms for this purpose is severely limited by the scaling of the transistor technology. In this article, we design an analog in-memory computation circuit for accelerating linear programming optimization problems. The scheme includes a memristive crossbar array and analog peripheral circuits that do not require DAC/ADC between each algorithm iteration. In addition, several key parameters related to nonideal device characteristics and interconnect parasitics are discussed for providing practical guidelines. Furthermore, three design schemes are proposed to alleviate the computation error caused by the interconnect resistance for a large-scale crossbar array implementation. Optimal design parameters are quantified under a given number of array size and memristive resistance. Finally, the proposed hardware accelerator and error mitigation techniques are applied to six real-world power system optimization problems. The results show that the average error of generator power and the overall cost is less than 3%. It is demonstrated that the proposed accelerator achieves area, delay, and energy consumption reductions of similar to 151x, similar to 33 x, and similar to 21 x, respectively, compared with the CMOS digital circuits at the 16-nm technology node for a 1000 x 1000 array with 6-bit precision.
linear programming optimization is critical to logistics management, engineering designs, and decision making in every area of the economy. Traditional hardware that using GPU and CPU platforms for this purpose is sig...
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ISBN:
(纸本)9781728157757
linear programming optimization is critical to logistics management, engineering designs, and decision making in every area of the economy. Traditional hardware that using GPU and CPU platforms for this purpose is significantly limited by the scaling transistor size. In this paper, an analog in-memory computation circuit is proposed to accelerate linear programming optimization problems. The proposed scheme includes a memristor crossbar array and analogue peripheral circuits that do not need ADC/DAC between each iteration of the algorithm. In addition, we discuss several key parameters related to interconnect parasitics and non-ideal device characteristics to provide practical guidelines. Furthermore, we propose three design schemes to mitigate the computation error that comes from the interconnect resistance in a large-scale crossbar array implementation. Optimal design parameters are quantitatively analyzed under a given number of memristance and array size. It is demonstrated that the proposed accelerator achieves energy consumption, area and delay reductions of similar to 21x, similar to 151x and similar to 33x, respectively, compared to the 16nm-technology CMOS digital circuits for a 1000x1000 array with a precision of 6-bit.
Prefilter synthesis is one of the important design steps of Horowitz's quantitative feedback theory (QFT) to robust feedback system synthesis. The prefilter is designed to achieve tracking specifications. In this ...
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The expansion of electric microgrids has led to the incorporation of new elements and technologies into the power grids, carrying power management challenges and the need of a well-designed control architecture to pro...
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The expansion of electric microgrids has led to the incorporation of new elements and technologies into the power grids, carrying power management challenges and the need of a well-designed control architecture to provide efficient and economic access to electricity. This paper presents the development of a flexible hourly day-ahead power dispatch architecture for distributed energy resources in microgrids, with cost-based or demand-based operation, built up in a multi-class Python environment with SQLExpress and InfluxDB databases storing the dispatcher and microgrid data, and its experimental implementation using Modbus communication. The experimental power dispatch architecture is described and each operation stage is detailed, including the considered mathematical models of the energy resources, the database management, the linear-programmingoptimization of power dispatch, and the Modbus setpoint writing. Validation studies of the proposed control system are presented for real-time digital-simulated devices and physical resources as a real application at the Universidad Pontificia Bolivariana (UPB) campus microgrid. The simulated and physical microgrid characteristics are described and the hourly dispatch results for generation, storage and load devices are presented, standing out as a reliable power management architecture for economic commitment and load peak shaving in simulated and real microgrids. The proposed architecture demonstrates its readiness for present and future electrical system challenges, effectively incorporating meteorological variations, renewable energy sources, and power demand fluctuations into the control framework, with a strong dependence on the quality of the meteorological forecast.
Energy management system (EMS) and energy storage system (ESS) can be of great significance to coping with issues of microgrid. In this paper, a microgrid consists of variable load, stable load, photovoltaic generatio...
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ISBN:
(纸本)9798350339345
Energy management system (EMS) and energy storage system (ESS) can be of great significance to coping with issues of microgrid. In this paper, a microgrid consists of variable load, stable load, photovoltaic generation and battery storage system. It's an effective way to make most of solar power. The microgrid with EMS and ESS can not only help reduce the emission of carbon dioxide but make the cost less than before. So the main goal of the article is to minimize the residental electricity cost and store the solar power when the weather is sunny. Two weather-based scenarios are formulated to deal with the photovoltaic generation (PVG) and ESS. linearoptimizationprogramming (LOP) is applied in this paper to address the issue of saving electricity cost and make renewable energy sources (RESs).
Battery energy storage in utility-scale transmission grids provides the benefit of fast response, however, efficient battery control in multi-battery multi-bus systems can be challenging. We present here a battery ope...
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ISBN:
(纸本)9781665485227
Battery energy storage in utility-scale transmission grids provides the benefit of fast response, however, efficient battery control in multi-battery multi-bus systems can be challenging. We present here a battery operation strategy based on forecasted load and line ampacity. The forecasted load is serviced via conventional generators in combination with battery energy storage whose outputs are computed using non-linearprogramming with the objective of minimizing total battery charging and discharging. The operating strategy takes into account battery degradation, line outages, and dynamic line rating. The forecasting model is based on attention convolutional neural network architecture with bidirectional long-short term memory layers forecasting over the range calculated using the sliding windows. The strategy is tested on 24-bus reliability test system and is shown to be effective at predicting battery action.
Water hammer is a transient flow phenomenon generated in a pipeline, when there is a sudden change in velocity, due to the closing of valves. This is particularly important for plants based on complicated hydraulic ci...
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Water hammer is a transient flow phenomenon generated in a pipeline, when there is a sudden change in velocity, due to the closing of valves. This is particularly important for plants based on complicated hydraulic circuits and piping, to avoid malfunctioning in the urban sewer network. In this study, the effect of a set of parameters: length, diameter and material of the pipe with and without surge tank on transient pressure is investigated by using the software HAMMER V8i. The results show that the maximum Transient Pressure is strongly influenced by an increase of 41.24% of the pipe diameter when the Surge Tank is not present. When the surge tank is inserted the transient pressure increases only of about 12.2%. So the surge tank can have a positive influence on the entire network. Moreover, the increase in the length will lead to a decrease in the Total Pressure of about 10% without Surge Tank and of 8.62% with Surge Tank. While the change in the roughness coefficient of the material used for the pipes will cause a decrease in the Total Pressure of about 42.6%, without Surge tank, and of 12.2% with Surge Tank.
In this article, a new approach based on linear programming optimization is proposed to solve the textile color formulation problem. The principle aims to find the appropriate dyes to mix and their exact concentration...
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In this article, a new approach based on linear programming optimization is proposed to solve the textile color formulation problem. The principle aims to find the appropriate dyes to mix and their exact concentrations, which, when applied correctly, produce the required color. Two ranges of reactive dyes were used for dyeing cotton fabrics. The objective function and all the constraints of the model are expressed linearly according to the decision variables. The objective function is to minimize the differences between the K/S spectra of the sample dyed with the proposed mixture and the target color. The constraints of the model are formulated based on Kubelka-Munk and Duncan theories in the same way as those of the single-constant model. The relevance of the method developed using linear programming optimization was evaluated and proven by calculating errors between the proposed and actual recipes, errors in K/S spectra, and Colour Measurement Committee CMC(2:1) differences between the reproduced and target colors. The proposed program showed very good results with very small values of errors and color differences.
As an increasing amount of data is gathered nowadays and stored in databases, the question arises of how to protect the privacy of individual records in a database even while providing accurate answers to queries on t...
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As an increasing amount of data is gathered nowadays and stored in databases, the question arises of how to protect the privacy of individual records in a database even while providing accurate answers to queries on the database. Differential Privacy (DP) has gained acceptance as a framework to quantify vulnerability of algorithms to privacy breaches. We consider the problem of how to sanitize an entire database via a DP mechanism, on which unlimited further querying is performed. While protecting privacy, it is important that the sanitized database still provide accurate responses to queries. The central contribution of this work is to characterize the amount of information preserved in an optimal DP database sanitizing mechanism (DSM). We precisely characterize the utility-privacy trade-off of mechanisms that sanitize databases in the asymptotic regime of large databases. We study this in an informationtheoretic framework by modeling a generic distribution on the data, and a measure of fidelity between the histograms of the original and sanitized databases. We consider the popular L1 -distortion metric, i.e., the total variation norm that leads to the formulation as a linear program (LP). This optimization problem is prohibitive in complexity with the number of constraints growing exponentially in the parameters of the problem. Our focus on the asymptotic regime enables us characterize precisely, the limit of the sequence of solutions to this optimization problem. Leveraging tools from discrete geometry, analytic combinatorics, and duality theorems of optimization, we fully characterize this limit in terms of a power series whose coefficients are the number of integer points on a multidimensional convex crosspolytope studied by Ehrhart in 1967. Employing Ehrhart theory, we determine a simple closed form computable expression for the asymptotic growth of the optimal privacy-fidelity trade-off to infinite precision. At the heart of the findings is a deep connection
This paper presents a novel rigorous procedure for assessing the lower bound of three dimensional (3D) slope stability based on the block element method. Within the framework of the lower bound theorem, a statically a...
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This paper presents a novel rigorous procedure for assessing the lower bound of three dimensional (3D) slope stability based on the block element method. Within the framework of the lower bound theorem, a statically allowable stress field satisfying the equilibrium, stress boundary, and yield conditions is constructed. Six equilibrium conditions including force and moment equilibrium are strictly satisfied for every block element. Additionally, two possibilities in the direction of resultant shear resistance on the slip surface, including unique direction and non-unique direction, are considered. In contrast to the previous studies adopting the assumptions on the inter-block forces, these forces are explicitly calculated in this study. The proposed linear programming optimization technique is well applicable to both unique and non-unique direction models. The simplicity and robustness of the rigorous method proposed in this study have been validated, by comparing the results with those obtained from various existing theories, considering four different types of slopes. The proposed method is then applied to investigate the stability of the left bank rock slope at Jinping-I Hydropower Station.
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