Tehnicki Vjesnik-Technical Gazette最新文献

{"title":"The Adaptive Quadratic Linear Unit (AQuLU): Adaptive Non Monotonic Piecewise Activation Function","authors":"","doi":"10.17559/tv-20230614000735","DOIUrl":"https://doi.org/10.17559/tv-20230614000735","url":null,"abstract":"","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82478522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep Learning Technique for Power Domain Non-Orthogonal Multiple Access Using Optimised LSTM in Cooperative Networks","authors":"Kavitha Gopalun, Deny John Samuvel, Deny John Samuvel","doi":"10.17559/tv-20221228104420","DOIUrl":"https://doi.org/10.17559/tv-20221228104420","url":null,"abstract":": Non-orthogonal Multiple Access (NOMA) is the technique proposed for multiple accesses in the fifth-generation (5G) cellular network. In NOMA, different users are allocated different power levels and are served using the same time/frequency Resource Blocks (RBs). The main challenges in existing NOMA systems are the limited channel feedback and the difficulty of merging them with advanced adaptive coding and modulation schemes. The 5G system in NOMA aims to access low latency, efficiency in superior spectra, and balanced user fairness. NOMA allows multiple users with different power levels to share resources in radio frequency time. The existing Orthogonal Multiple Access (OMA) system produces high latency, high computational complexity, and throughput complexity in modifying wireless channels. To overcome these issues, this paper proposed optimising deep learning-based power domain NOMA of Long Short-Term Memory (LSTM) with particles Swarm optimisation (PSO) technique. This proposed work (LSTM-PSO) is deployed with a Cooperative network model. The advantage of LSTM-PSO in Cooperative Non-orthogonal Multiple Access (CNOMA) is that it provides high performance, better utilisation of downlink, efficiency in sharing of resources, enhancing the activity of users, capacity of the base station and improving quality of service, estimation of channel condition. LSTM-PSO got a higher accuracy rate of 92.05%, LSTM got 86.45%, PSO got 88.13%, and the accuracy rate of ANN and DNN was 83.76% and 84.70%.","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80740365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"H-infinity Variable-Pitch Control for Wind Turbines Based on Takagi-Sugeno Fuzzy Theory","authors":"Shengsheng Qin, Sze Song Ngu, Chaoqun Zhang, Hui Cai, Yujian Chen, Ruiqi Chen, Tingxuan Liu","doi":"10.17559/tv-20230320000458","DOIUrl":"https://doi.org/10.17559/tv-20230320000458","url":null,"abstract":": When the wind speed is above the rated value, the output power of the wind turbine should be maintained at the rated value in order to prevent the power generation system from overheating. In addition, the natural wind speed will fluctuate randomly in a large range of values, making the traditional control effect not ideal. This paper presents a novel H-infinity (H ∞ ) pitch control strategy for Wind Turbine Generators (WTGs), which can make the rotor speed and output power constant when the wind speed changes in a large range. In order to shorten response time and reduce overshoot, in the specific solution, the control method combines the H ∞ theory and the Takagi-Sugeno (T-S) fuzzy theory. Firstly, the linearized models of several operating points were obtained with the T-S fuzzy theory. Then, a robust controller was designed for each linear sub-system based on the H ∞ control theory. Furthermore, the controllers of the sub-systems were superimposed into a global controller for the entire system through the membership function. Finally, modeling and simulation were carried out in MATLAB/SIMULINK. The simulation results show that when the wind speed changes above the rated speed, the rotor speed can be maintained at the rated value, and the output power also can be maintained at the rated value. Compared with the optimal control, the response speed of this method is faster and the overshoot is smaller. It provides a new idea for the pitch angle control of wind turbine.","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87914494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spider Monkey Optimization Based Optimal Sizing of Battery Energy Storage for Micro-Grid","authors":"","doi":"10.17559/tv-20221109072844","DOIUrl":"https://doi.org/10.17559/tv-20221109072844","url":null,"abstract":"","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76623211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of Single-phase PWM Rectifier Based on PI Double-loop Control","authors":"Kezhou Bai, Qushan Chen","doi":"10.17559/tv-20230626000761","DOIUrl":"https://doi.org/10.17559/tv-20230626000761","url":null,"abstract":": In this paper, the mathematical model of PWM rectifier is analyzed first, and the rotating coordinate system transformation is used to convert the mathematical model to frequency domain, and the control model is established through the frequency domain model. Since the d -axis and q -axis currents are coupled with each other, this paper adopts the current feedforward processing to decouple the current loop, and introduces the PI regulator as the main control link between the current loop and the voltage loop to obtain the control models of the current inner loop and the voltage outer loop. In this paper, the current inner loop control model and the voltage outer loop control model are simulated in Simulink, and root locus analysis and Bode diagram analysis are used to first determine the parameters of the current inner loop within the expected range of the relevant parameters, and then determine the parameters of the voltage outer loop by the control model of the current inner loop. A double-loop control system with better performance is finally derived.","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74407213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis on Supply Chain Risk Factors of Prefabricated Buildings Using AHP-DEMATEL-ISM Model","authors":"Qiang Cai, Yunchao Du, Renxiang Wang","doi":"10.17559/tv-20230508000614","DOIUrl":"https://doi.org/10.17559/tv-20230508000614","url":null,"abstract":": Given the numerous participants in the supply chain of prefabricated buildings and the great difficulty in improving risk management and control level, influencing factors through the literature review method were identified. Then, 7 first-level indexes and 23 second-level indexes were extracted. An influence index system for supply chain risks of prefabricated buildings was established. Comprehensively considering the importance and correlation of various influencing factors, the AHP-DEMATEL (Analytic Hierarchy Process and Decision-making Trial and Evaluation Laboratory) combined model was constructed, which solved the one-sided problem of the weight result of a single model. Then, the ISM (Interpretative Structural Modelling) model could be used to show the characteristics of the structural relationship of influencing factors hierarchically, and the fundamental supply chain risk factors were more accurately and clearly explored using the AHP-DEMATEL-ISM model. Results show that: (1) Logistics transportation distance, damage to prefabricated components during transportation, and unreasonable control of assembly period are the fundamental factors affecting the risk of prefabricated buildings, among which logistics transportation distance and damage to prefabricated components during transportation are the resulting factors, and the unreasonable control of the assembly period is the causal factor, but the factor weight is low because of the difficulty in short-term improvement. (2) Component production technology and equipment, transportation distance, and punctuality of product supply account for a high weight in the supply chain risk assessment index system of prefabricated buildings. (3) A total of 11 factors, such as inconformity of product design and standard, immature design technology level, component production technology and equipment, and quality of purchased materials, affect the supply chain risk of prefabricated buildings and are also causal factors with high weights. Conclusions obtained in the study provide a theoretical basis for the supply chain risk control of prefabricated buildings to a certain extent and also present a new perspective for the supply chain risk assessment of prefabricated buildings.","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84180964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Improved Apriori Algorithm for Association Rule Mining in Employability Analysis","authors":"Fang Peng, Yuhui Sun, Zigen Chen, Jing Gao","doi":"10.17559/tv-20230327000481","DOIUrl":"https://doi.org/10.17559/tv-20230327000481","url":null,"abstract":": The wide application of emerging advanced technologies causes significant changes in the development trend of the employment market. The lack of flexible and easy-to-implement analysis methods challenges general maritime education practitioners to understand the developing trends. This research proposed the improved Apriori algorithm to explore employment preference by identifying the association rule of the employability indicators and the employment status. The candidate generation methods are optimised based on the questionnaire design to generate fewer candidates. The minimum support value is automatically generated to reduce the reliance on analysis expertise and improve accuracy. To validate the algorithm, a questionnaire for the maritime graduate is used to collect employment data to test the efficiency and capability of the improved algorithm. The computation time for different data set sizes shows that the improvement could improve the algorithm's effectiveness. The algorithm also successfully identifies significant employment preference that certain employment types emphasise specific employability skills, such as responsibility and core professional skills. The results suggest that the improved A algorithm could reduce the computing burden and identify the employment preference from questionnaire data. This research provides easy-to-use and flexible analysis tools, which could reduce the computing expertise required for education practitioners.","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83207925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Universal Model for the Quality Analysis of Aluminium Alloys Castings","authors":"A. Pacana, K. C. Ń. Ska","doi":"10.17559/tv-20230128000283","DOIUrl":"https://doi.org/10.17559/tv-20230128000283","url":null,"abstract":": The production of products in foundry technology is fraught with many problems, including the impossibility of controlling all parameters affecting casting quality. It is important to take effective improvement measures related to the implication of non-destructive testing (NDT), but these methods are rarely combined in the diagnostic cycle. As part of quality assurance, it is also important to identify the root causes of problems. In view of this, it is appropriate to develop a model that facilitates diagnosis and the search for the key causes of nonconformity, which would be a combination of NDT and quality management methods. The originality of the model presented in the study is reflected in the combination of NDT and quality management methods. The model presents a universal method that can be implemented in foundries to ensure the stability of production processes. The application of the model brings tangible benefits in the form of an increase in the speed of detection and a reduction in non-conformities in aluminium castings, which significantly increases the quality level of the products offered. Further research directions will address the application of the model within foundry processes characterised by loss of quality stability.","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88753515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Method for Automatically Generating Join Queries Based on Relations-Attributes Distance Matrix over Data Lakes","authors":"","doi":"10.17559/tv-20230402000493","DOIUrl":"https://doi.org/10.17559/tv-20230402000493","url":null,"abstract":"","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73624442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Planning of Electric Vehicle Charging Facilities on Highways Based on Chaos Cat Swarm Simulated Annealing Algorithm","authors":"","doi":"10.17559/tv-20230320000459","DOIUrl":"https://doi.org/10.17559/tv-20230320000459","url":null,"abstract":"","PeriodicalId":49443,"journal":{"name":"Tehnicki Vjesnik-Technical Gazette","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80423759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}