Multi-objective optimization for control parameters of underwater gliders considering effect of uncertain input errors

2021 ◽  
pp. 095440622110364
Author(s):  
Hongyu Wu ◽  
Wendong Niu ◽  
Shuxin Wang ◽  
Shaoze Yan
Keyword(s):  
Performance Evaluation ◽  
Energy Utilization ◽  
Utilization Rate ◽  
Control Parameters ◽  
Underwater Glider ◽  
Multi Objective Optimization ◽  
Position Accuracy ◽  
Optimization Calculation ◽  
Uncertain Input ◽  
Evaluation Parameters

In actual application, the energy utilization rate of underwater glider directly affects the total voyage range. When underwater glider is used for executing exploration mission for a fixed point, the position that the glider resurfaces should be accurate enough. In this paper, we employ a multi-objective optimization method to determine the control parameters values that can maximize the position accuracy that the glider resurfaces and the energy utilization rate simultaneously. Especially, the optimization of this paper considers the effect of uncertain input errors. The control parameters include the net buoyancy adjustment amount and the movable mass block translation amount. The input errors include the control parameters errors, the motion depth error and the current. Based on the dynamic model of an underwater glider, we propose the calculation model and evaluation flow that are used for analyzing the glider position accuracy and energy utilization rate, considering the effect of uncertain input errors. Besides, a combinatorial experimental design method is proposed to calculate the performance evaluation parameters under different control parameters values. Then the radial basis function neural network is employed to establish the surrogate models of performance evaluation parameters to participate in the optimization calculation, which can improve the optimization efficiency. After optimization calculation based on the non-dominated sorting genetic algorithm II, we obtain a Pareto optimal set consisting of 257 sets of non-dominated solutions. Finally, the selection rule of optimal control parameters values is given, and the optimization results are validated under 3 sets of solutions. This research may be valuable for the improvement of the glider work quality.

scholarly journals Integrated Double-Sided Random Microlens Array Used for Laser Beam Homogenization

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 673
Author(s):  
Wei Yuan ◽  
Cheng Xu ◽  
Li Xue ◽  
Hui Pang ◽  
Axiu Cao ◽  
...  
Keyword(s):  
Laser Beam ◽  
Microlens Array ◽  
Energy Utilization ◽  
Utilization Rate ◽  
Periodic Lattice ◽  
Lattice Distribution ◽  
Speckle Field ◽  
High Laser ◽  
Alignment Problem ◽  
In Series

Double microlens arrays (MLAs) in series can be used to divide and superpose laser beam so as to achieve a homogenized spot. However, for laser beam homogenization with high coherence, the periodic lattice distribution in the homogenized spot will be generated due to the periodicity of the traditional MLA, which greatly reduces the uniformity of the homogenized spot. To solve this problem, a monolithic and highly integrated double-sided random microlens array (D-rMLA) is proposed for the purpose of achieving laser beam homogenization. The periodicity of the MLA is disturbed by the closely arranged microlens structures with random apertures. And the random speckle field is achieved to improve the uniformity of the homogenized spot by the superposition of the divided sub-beams. In addition, the double-sided exposure technique is proposed to prepare the rMLA on both sides of the same substrate with high precision alignment to form an integrated D-rMLA structure, which avoids the strict alignment problem in the installation process of traditional discrete MLAs. Then the laser beam homogenization experiments have been carried out by using the prepared D-rMLA structure. The laser beam homogenized spots of different wavelengths have been tested, including the wavelengths of 650 nm (R), 532 nm (G), and 405 nm (B). The experimental results show that the uniformity of the RGB homogenized spots is about 91%, 89%, and 90%. And the energy utilization rate is about 89%, 87%, 86%, respectively. Hence, the prepared structure has high laser beam homogenization ability and energy utilization rate, which is suitable for wide wavelength regime.

scholarly journals Calculation and Analysis of the Interval Power Flow for Distributed Energy System Based on Affine Algorithm

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 600
Author(s):  
Bin Ouyang ◽  
Lu Qu ◽  
Qiyang Liu ◽  
Baoye Tian ◽  
Zhichang Yuan ◽  
...  
Keyword(s):  
Power Flow ◽  
Load Condition ◽  
Energy Systems ◽  
Energy System ◽  
Optimal Operation ◽  
Energy Utilization ◽  
Utilization Rate ◽  
Distributed Energy ◽  
Low Load ◽  
Distributed Energy System

Due to the coupling of different energy systems, optimization of different energy complementarities, and the realization of the highest overall energy utilization rate and environmental friendliness of the energy system, distributed energy system has become an important way to build a clean and low-carbon energy system. However, the complex topological structure of the system and too many coupling devices bring more uncertain factors to the system which the calculation of the interval power flow of distributed energy system becomes the key problem to be solved urgently. Affine power flow calculation is considered as an important solution to solve uncertain steady power flow problems. In this paper, the distributed energy system coupled with cold, heat, and electricity is taken as the research object, the influence of different uncertain factors such as photovoltaic and wind power output is comprehensively considered, and affine algorithm is adopted to calculate the system power flow of the distributed energy system under high and low load conditions. The results show that the system has larger operating space, more stable bus voltage and more flexible pipeline flow under low load condition than under high load condition. The calculation results of the interval power flow of distributed energy systems can provide theoretical basis and data support for the stability analysis and optimal operation of distributed energy systems.

Flatness Assessment System of Ultra-Wide Tandem Cold Rolling Mill

2014 ◽  
Vol 529 ◽  
pp. 415-419
Author(s):  
Ren Ren Bao ◽  
Jie Zhang ◽  
Hong Bo Li ◽  
Jun Wang ◽  
Yu Gang Chu ◽  
...  
Keyword(s):  
Assessment System ◽  
Control Parameters ◽  
Calculation Methods ◽  
Cold Rolling Mill ◽  
Tandem Cold Rolling ◽  
Methods Of Evaluation ◽  
Flatness Control ◽  
Flatness Pattern Recognition ◽  
Flatness Error ◽  
Evaluation Parameters

Many complex waviness defects occur during the production process of ultra wide TCMs, flatness idex I can not meet the demands of analyzing these problems. Therefore flatness pattern recognition considering cubic patterns is introduced to provide a flatness evaluation parameter. Combining the calculation methods and statistical methods of evaluation parameters, a flatness assessment system is programmed with Matlab GUI, which provides functions such as representing the flatness of previous strips, recognizing the flatness error and making statistics. After verifying of actual flatness measured value, the system is proved to be effective, which provides theoretical basis and data support for mastering the flatness quality and optimizing flatness control parameters.

scholarly journals Analysis of total carbon emission of the logistics industry in Guangdong and solutions to emission reduction

2021 ◽  
Vol 245 ◽  
pp. 01020
Author(s):  
Aixia Xu ◽  
Xiaoyong Yang
Keyword(s):  
Energy Consumption ◽  
Carbon Emissions ◽  
Carbon Emission ◽  
Energy Utilization ◽  
Total Carbon ◽  
Utilization Rate ◽  
Low Carbon ◽  
Logistics Industry ◽  
Direct Energy ◽  
Reduce Emissions

The input-output method is employed in this study to measure the total carbon emission of the logistics industry in Guangdong. The findings revealed that the carbon emission of direct energy consumption of the logistics industry in Guangdong is far above the actual carbon emissions, the second and third industries play a significant role in carbon emission of indirect energy consumption in the logistics industry in Guangdong. To reduce energy consumption and carbon emissions in Guangdong, it is not only important to control the carbon emissions in the logistics industry, but strengthen carbon emission detection in relevant industries, improve the energy utilization rate and reduce emissions in other industries, and move towards low-carbon sustainable development.

scholarly journals Scrutinizing Attacks and Evaluating Performance Appraisal Parameters via Feature Selection in Intrusion Detection System

2021 ◽  
Author(s):  
Navroop Kaur ◽  
Meenakshi Bansal ◽  
Sukhwinder Singh S
Keyword(s):  
Feature Selection ◽  
Performance Evaluation ◽  
Intrusion Detection ◽  
Intrusion Detection System ◽  
Detection System ◽  
Denial Of Service ◽  
Cyber Attacks ◽  
Support Vector ◽  
K Nearest Neighbor ◽  
Evaluation Parameters

Abstract In modern times the firewall and antivirus packages are not good enough to protect the organization from numerous cyber attacks. Computer IDS (Intrusion Detection System) is a crucial aspect that contributes to the success of an organization. IDS is a software application responsible for scanning organization networks for suspicious activities and policy rupturing. IDS ensures the secure and reliable functioning of the network within an organization. IDS underwent huge transformations since its origin to cope up with the advancing computer crimes. The primary motive of IDS has been to augment the competence of detecting the attacks without endangering the performance of the network. The research paper elaborates on different types and different functions performed by the IDS. The NSL KDD dataset has been considered for training and testing. The seven prominent classifiers LR (Logistic Regression), NB (Naïve Bayes), DT (Decision Tree), AB (AdaBoost), RF (Random Forest), kNN (k Nearest Neighbor), and SVM (Support Vector Machine) have been studied along with their pros and cons and the feature selection have been imposed to enhance the reading of performance evaluation parameters (Accuracy, Precision, Recall, and F1Score). The paper elaborates a detailed flowchart and algorithm depicting the procedure to perform feature selection using XGB (Extreme Gradient Booster) for four categories of attacks: DoS (Denial of Service), Probe, R2L (Remote to Local Attack), and U2R (User to Root Attack). The selected features have been ranked as per their occurrence. The implementation have been conducted at five different ratios of 60-40%, 70-30%, 90-10%, 50-50%, and 80-20%. Different classifiers scored best for different performance evaluation parameters at different ratios. NB scored with the best Accuracy and Recall values. DT and RF consistently performed with high accuracy. NB, SVM, and kNN achieved good F1Score.

Review on Image Representation Compression and Retrieval Approaches

2019 ◽  
pp. 203-231
Author(s):  
Lalit B. Damahe ◽  
Nileshsingh V. Thakur
Keyword(s):  
Computer Vision ◽  
Performance Evaluation ◽  
Personal Computer ◽  
Compression Ratio ◽  
Image Representation ◽  
Traffic Monitoring ◽  
Time Compression ◽  
Key Issues ◽  
And Storage ◽  
Evaluation Parameters

Image representation and compression is one of the important fields of computer vision that contribute to the reduction of size of an image and other types of application areas such as image restoration, retrieval, etc. Image representation is important with respect to storage of image information, and it further extends to the compression, which may be lossy or lossless. Image compression can be applied to various applications which mainly include medical imaging, traffic monitoring, military, multimedia transmission, smart cell devices, and almost in all the domains that require less transmission and storage cost, specifically image retrieval processing. This chapter presents the various image representation compression and retrieval approaches. The retrieval approaches on personal computer and smart cell devices are discussed. Finally, the key issues are identified for image representation compression and retrieval on the basis of performance evaluation parameters like encoding time, decoding time, compression ratio, precision, recall, and elapsed time.

scholarly journals An Analysis of the Current Status of Woody Biomass Gasification Power Generation in Japan

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4903
Author(s):  
Yasutsugu Baba ◽  
Andante Hadi Pandyaswargo ◽  
Hiroshi Onoda
Keyword(s):  
Power Generation ◽  
Moisture Content ◽  
Tree Species ◽  
Woody Biomass ◽  
Biomass Gasification ◽  
Energy Utilization ◽  
Current Status ◽  
Utilization Rate ◽  
Small Scale ◽  
Bio Oil

Forests cover two-thirds of Japan’s land area, and woody biomass is attracting attention as one of the most promising renewable energy sources in the country. The Feed-in Tariff (FIT) Act came into effect in 2012, and since then, woody biomass power generation has spread rapidly. Gasification power generation, which can generate electricity on a relatively small scale, has attracted a lot of attention. However, the technical issues of this technology remain poorly defined. This paper aims to clarify the problems of woody biomass gasification power generation in Japan, specifically on the challenges of improving energy utilization rate, the problem of controlling the moisture content, and the different performance of power generation facilities that uses different tree species. We also describe the technological development of a 2 MW updraft reactor for gasification and bio-oil coproduction to improve the energy utilization rate. The lower heating value of bio-oil, which was obtained in the experiment, was found to be about 70% of A-fuel oil. Among the results, the importance of controlling the moisture content of wood chips is identified from the measurement evaluation of a 0.36 MW-scale downdraft gasifier’s actual operation. We discuss the effects of tree species variation and ash on gasification power generation based on the results of pyrolysis analysis, industry analysis for each tree species. These results indicate the necessity of building a system specifically suited to Japan’s climate and forestry industry to allow woody biomass gasification power generation to become widespread in Japan.

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