Ship emissions is one of the main components of port pollution. Inefficient waterway management may not only result in additional waiting time of ships, but also the aggravated emissions in port. With special consider...
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Ship emissions is one of the main components of port pollution. Inefficient waterway management may not only result in additional waiting time of ships, but also the aggravated emissions in port. With special consideration of combining scheduling optimization and speed reduction of ships in port, this paper proposed a new emission reduction method, called ship scheduling with speed reduction (SSSR). Performance of the SSSR method has been testified through comparisons between the new and traditional ship emission reduction methods based on the navigation safety under three different strategies. The effectiveness of the new ship emission reduction method has been testified through a series of experiments with practical data in port. Especially, under various stages in port, the emissions of ships can be reduced by 8.0%-11.9% and the traffic efficiency can be improved by 3.8%-6.2%.
This article describes a new approach in antenna design automation. We propose to use a micro-array of coupled antennas loaded by impedances and to perform the optimization of these impedance values in order to reach ...
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ISBN:
(纸本)9788831299022
This article describes a new approach in antenna design automation. We propose to use a micro-array of coupled antennas loaded by impedances and to perform the optimization of these impedance values in order to reach specific design goals. In particular, we present a demonstration for dual-band GNSS that requires good RHCP gain (in the range -2 dBic to 0 dBic) and low LHCP gain (below -10 dBic). The proposed automated design process has been able to meet these requirements jointly in L2 (1215-1240 MHz) and L1 frequency bands (1560-1610 MHz). A prototype has been fabricated, and characterized in anechoic chamber to validate the proposed design methodology.
Recent progress on deep learning relies heavily on the quality and efficiency of training algorithms. In this paper, we develop a fast training method motivated by the nonlinear Conjugate Gradient (CG) framework. We p...
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ISBN:
(数字)9783030865238
ISBN:
(纸本)9783030865238;9783030865221
Recent progress on deep learning relies heavily on the quality and efficiency of training algorithms. In this paper, we develop a fast training method motivated by the nonlinear Conjugate Gradient (CG) framework. We propose the Conjugate Gradient with Quadratic line-search (CGQ) method. On the one hand, a quadratic line-search determines the step size according to current loss landscape. On the other hand, the momentum factor is dynamically updated in computing the conjugate gradient parameter (like Polak-Ribiere). Theoretical results to ensure the convergence of our method in strong convex settings is developed. And experiments in image classification datasets show that our method yields faster convergence than other local solvers and has better generalization capability (test set accuracy). One major advantage of the paper method is that tedious hand tuning of hyperparameters like the learning rate and momentum is avoided.
Accurate prediction of wind power generation is complex due to stochastic component, but can play a significant role in minimizing operating costs, and improving reliability and security of a power system. This paper ...
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Accurate prediction of wind power generation is complex due to stochastic component, but can play a significant role in minimizing operating costs, and improving reliability and security of a power system. This paper proposes a hybrid deep learning model to accurately forecast the very-short-term (5-min and 10-min) wind power generation of the Boco Rock Wind Farm in Australia. The model consists of a convolutional neural network, gated recurrent units (GRU) and a fully connected neural network. To improve performance, the hyper-parameters of the model are tuned using the Harris Hawks optimization algorithm. The effectiveness of the proposedmodel is evaluated against other advanced models, including multilayer feedforward neural network (NN), recurrent neural network (RNN), long short-termmemory(LSTM) and GRU. The forecasting model demonstrates around 38% and 24% higher accuracy as compared to the 5- and 10-min forecasting of the NN model, respectively.
The winding design of an electrical machine is an important task in the whole design process. This leads, for a part, to the magneto motive force which is one of the main quantities to manage for electrical machine pe...
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The winding design of an electrical machine is an important task in the whole design process. This leads, for a part, to the magneto motive force which is one of the main quantities to manage for electrical machine performances. Indeed, the latter is directly linked to that of the air gap magnetic flux density and thus to the torque ripples, vibration and then noise. This paper proposes to reduce the MMF harmonic content by means of optimization process using mono-objective or multi-objective algorithms with discrete and continuous variables. For this aim, optimization algorithm is coupled with an analytical tool which enables calculating quickly the MMF harmonic content from winding parameters. A winding optimization of three different windings with the same number of pole pairs is proposed to show the suitability of this process.
In the present work, an innovative configuration is proposed based on solar pre-heating concept and biomass direct-combustion for combined production of electricity, hot water and cooling load. The studied system cons...
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In the present work, an innovative configuration is proposed based on solar pre-heating concept and biomass direct-combustion for combined production of electricity, hot water and cooling load. The studied system consists of an externally fired gas turbine, a trans-critical organic Rankine cycle, and a Li-Br/H2O absorption refrigeration cycle. The proposed system is thoroughly analyzed from the energy, exergy, and exergo-economic viewpoint. The results of the exergo-economic analysis demonstrate that the energy and exergy efficiencies of the reference case are 55.56% and 20.38% and the product cost rate is 26.4 $/h. Comparing the thermodynamic results to the literature, it is proved that the proposed system generates a considerably higher amount of power, heating, and cooling load which results in an improvement of energy efficiency by about 10%. In further, the main design parameters of each cycle are parametrically assessed to gain a comprehensive understanding of the system behavior. Finally, a new multi-objective optimization algorithm called multi-objective multi-verse optimizer (MOMVO) is employed to maximize exergy efficiency and minimize the product cost rate of the system. Compared to the base case, TOPSIS implementation revealed that the optimal final solution of the Pareto-frontier found by the MOMVO has about 9% higher second law efficiency while the product cost rate is decreased by around 6%. This result proved the better performance of the MOMVO compared to other conventional evolutionary-based multi-objective optimzation algorithms.
Unmanned aerial vehicles (UAV) are utilized in numerous industries and in recent years with the advent of learning techniques, the focus is now on developing Self - aware UAVs that rely on an array of environmental se...
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ISBN:
(数字)9781624106101
ISBN:
(纸本)9781624106101
Unmanned aerial vehicles (UAV) are utilized in numerous industries and in recent years with the advent of learning techniques, the focus is now on developing Self - aware UAVs that rely on an array of environmental sensors to replace a pilots awareness of the structural capability of the UAV and provide time critical analysis of the sensor data to make complex decisions in real time. Hence a self-aware UAV is capable of dynamically and autonomously sense its structural state and act accordingly to perform the required task. This work proposes a data driven approach to producing estimates of capability for a self - aware UAV and optimizing the placement of sensors to minimize the error between true and predicted capability. This process involves using high physics-based models such as ASWING in tandem with Akselos modeler, a cloud based FEA solver, to produce an offline library that comprises of damage states along with capabilities corresponding to different kinematic states of a UAV. Further this generated information is used to create a classification model which is used to predict the capability for real time data. The classification model serves as an enabler for the optimization algorithm to measure the error value between the true and the predicted capability of the UAV to determine the optimum sensor placement. We demonstrate the improvement in performance through a comparison between optimum placement and the standard placement of sensors. We also provide evidence of proof of concept of how dynamic sampling of information can improve the process of capability estimation in self - aware aerospace vehicles.
Current maintenance intervals of mechanical systems are scheduled a priori based on the life of the system, resulting in expensive maintenance scheduling, and often undermining the safety of passengers. This problem i...
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ISBN:
(数字)9781624106095
ISBN:
(纸本)9781624106095
Current maintenance intervals of mechanical systems are scheduled a priori based on the life of the system, resulting in expensive maintenance scheduling, and often undermining the safety of passengers. This problem is particularly relevant in the development of autonomous vehicles, especially in the concept of urban air mobility. The actual usage of the vehicle will be used to predict stresses in the structure and therefore to define maintenance scheduling. Machine learning algorithms, specifically the Random Forest algorithm, can be used to create surrogate finite element models that map a reduced set of data coming from real-time measurements of a structure into a detailed/high-fidelity finite element analysis model of the same system. As a result, the FEA-based machine learning approach directly estimates the dynamic response over the entire system during operations, thus improving the ability to define ad-hoc, safe and efficient maintenance procedures. The predictive performance of random forest algorithm is presented for direct estimation of the acceleration distribution over a beam structure.
Emerging trends, development and growth of industrial-networked control systems (i-NCSs) with real-time communication network drive it more susceptible to malicious intended intrusion and attack. Due to numerous advan...
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ISBN:
(纸本)9781728187532
Emerging trends, development and growth of industrial-networked control systems (i-NCSs) with real-time communication network drive it more susceptible to malicious intended intrusion and attack. Due to numerous advantages such as reduced maintenance, ease to install, ease of diagnosis and system wiring draws attention to use in various industrial and critical fields. The control performance and robust stability of NUS is directly related to reliable and successful transmission of critical information's. So in this paper an approach is illustrated to alleviate the effects and avert the unwanted intended intrusive data through the designing of stability conditions and optimized control policies. An unwanted intrusion effects also forced us to design a controlled system, which is hard to be estimated by attackers, through the applications of optimization algorithms.
Dual thrust profile using single chamber offers great opportunity in extending range of tactical missiles by mitigating the drawbacks of other dual thrust motor arrangements. This method for achieving dual thrust prof...
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ISBN:
(数字)9781624106095
ISBN:
(纸本)9781624106095
Dual thrust profile using single chamber offers great opportunity in extending range of tactical missiles by mitigating the drawbacks of other dual thrust motor arrangements. This method for achieving dual thrust profile can be implemented using different grains arrangement e.g. tubular-tubular, star tubular, star-end burning etc. or different propellant compositions. In this paper, Star-star configuration is presented. The advantage of the proposed arrangement is higher volumetric loading compared to other arrangement. In addition, effects of different geometric parameters on dual thrust profile are investigated. Finally Genetic algorithmoptimization module is applied in order to fit the design into certain objective mission. Results showed that number of star points and star angular fraction affect only transition phase, while geometry of narrow star affect both booster and sustainer phase.
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