Boris Jalušić, Marin Vukovojac, Tomislav Lesičar, Mato Perić, Ivica Skozrit, Z. Tonković
{"title":"Modelling of crack propagation in welded structure using a separated phase-field approach","authors":"Boris Jalušić, Marin Vukovojac, Tomislav Lesičar, Mato Perić, Ivica Skozrit, Z. Tonković","doi":"10.23919/SpliTech55088.2022.9854367","DOIUrl":"https://doi.org/10.23919/SpliTech55088.2022.9854367","url":null,"abstract":"In this study, a separated phase-field procedure has been utilized to model crack propagation in compact tension (CT) specimen machined from the pre-welded structure. The influence of the attained welding residual stresses and plastic strains on the crack propagation has been investigated. Herein, the residual stress values measured experimentally have been taken from the scientific literature while the plastic strains have been estimated using the hardening law. The phase-field (PF) framework has been implemented into finite element (FE) software Abaqus and Fortran via user subroutines. All the numerical computations have been done using plane strain assumption. It was observed that the presented PF approach can properly model crack propagation through the welded structure.","PeriodicalId":295373,"journal":{"name":"2022 7th International Conference on Smart and Sustainable Technologies (SpliTech)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122350967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Design of Supershaped Dielectric Lens Antenna at 140 GHz for 6 G applications","authors":"G. Mevoli, P. Bia, L. Mescia","doi":"10.23919/SpliTech55088.2022.9854353","DOIUrl":"https://doi.org/10.23919/SpliTech55088.2022.9854353","url":null,"abstract":"In this paper, the design of supershaped dielectric lens antennas is presented. A dedicated high frequency hybrid modeling approach based on geometrical tube tracing and physical optics approximation is adopted to analyze the radiation properties as well as to evaluate the impact of the lens shape on the far field outside the lens. The effects of the multiple internal reflections are properly taken into account, too. The developed modeling procedure was applied at the frequency 140 GHz included into the unexplored frequency bands for the sixth generation (6G) of wireless communication systems. In particular, it was used to define the lens geometry providing a shaped radiation pattern having three high gain main lobes. Moreover, the effects on the radiation pattern properties due to the lens rotation around its vertical axis were investigated.","PeriodicalId":295373,"journal":{"name":"2022 7th International Conference on Smart and Sustainable Technologies (SpliTech)","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114227596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Vujanovic, Tibor Bešenić, Miloš Radojević, N. Manić
{"title":"Numerical Modelling of Nitrogen Oxides Formation During Combustion of Pulverised Fuel","authors":"M. Vujanovic, Tibor Bešenić, Miloš Radojević, N. Manić","doi":"10.23919/SpliTech55088.2022.9854251","DOIUrl":"https://doi.org/10.23919/SpliTech55088.2022.9854251","url":null,"abstract":"Pollutants originating from pulverised solid fuel combustion systems are investigated with numerical simulations augmented by data from the fundamental experimental research. Nitrogen oxides formation model, with fuel nitrogen as a main pathway mechanism, was implemented in the computational fluid dynamics model for coal combustion. Partitioning of nitrogen contained in fuel is among the main characteristics influencing the final production of pollutants, but it is highly dependent on fuel type and combustion parameters. The experimental determination of intermediate chemical species during the pyrolysis of a coal sample was performed on a thermogravimetric analysis-mass spectrometry system, and it shows that the fuel nitrogen is uniformly emitted as hydrogen cyanide and ammonia-52.2% and 47.8%-while the hydrogen cyanide production pathway from char is dominant over the volatiles-84.3% and 15.7% respectively. The obtained results on the ratio of ammonia to hydrogen cyanide during fuel nitrogen devolatilisation were used as input parameters in numerical simulations. The improved model shows good results in simulating pyrolysis, making it suitable for modelling and optimisation of thermal utilisation processes on industrial scales.","PeriodicalId":295373,"journal":{"name":"2022 7th International Conference on Smart and Sustainable Technologies (SpliTech)","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115856386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Ascione, N. Bianco, T. Iovane, M. Mastellone, G. M. Mauro, F. Tariello
{"title":"Energy refurbishment of a University Mediterranean building: evaluation of the incentive share to achieve a cost-effective nZEB standard","authors":"F. Ascione, N. Bianco, T. Iovane, M. Mastellone, G. M. Mauro, F. Tariello","doi":"10.23919/SpliTech55088.2022.9854347","DOIUrl":"https://doi.org/10.23919/SpliTech55088.2022.9854347","url":null,"abstract":"To achieve the goal of decarbonization by 2050, the existing buildings, both private and public, should be renovated. Concerning public buildings, the annual renovation rate of 3% envisaged by Directive 2012/27/EU should be increased to meet the objectives set at the European level in terms of energy efficiency. The stringent targets have been confirmed by the “fit for 55” package. In this paper, a university building in Naples (South Italy, typical Mediterranean Climate) is investigated. It is brought to the standard of nearly zero energy building through different energy efficiency measures. Based on the lifespan of the individual retrofit measure, a reasonable payback period is set. Then the incentive needed to get it is evaluated. What emerges is that greater incentives are required, even up to 80%, for interventions that have a longer lifespan, i.e., the thermal insulation of the building envelope. A form of incentive equal to 40% of the investment, on the other hand, would make it possible to pay off all the interventions in about 10 years, insulation of external vertical walls and roof, replacement of transparent building envelope and installed systems, installation of a photovoltaic system. This solution would make the building a nZEB allowing a reduction of the total primary energy consumption of about 41% and a reduction of CO2 emissions of 46%.","PeriodicalId":295373,"journal":{"name":"2022 7th International Conference on Smart and Sustainable Technologies (SpliTech)","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131183151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Secure and Efficient Web of Things Digital Twins using Permissioned Blockchains","authors":"Iakovos Pittaras, George C. Polyzos","doi":"10.23919/SpliTech55088.2022.9854219","DOIUrl":"https://doi.org/10.23919/SpliTech55088.2022.9854219","url":null,"abstract":"The growing popularity and features of digital twins have made them key elements in Industry 4.0 and the Internet of Things (IoT). In this paper, we propose the use of digital twins as an indirection mechanism, instead of accessing directly the actual IoT devices, in order to offer secure sensing and actuation in IoT systems through Distributed Ledger Technologies (DLTs), which can enhance the security and transparency of such digital twins. In particular, we leverage advances in Web of Things (WoT) and permissioned blockchains to build flexible and secure digital twins. Specifically, we build smart contract-based digital twins of IoT devices that follow W3C's WoT standards. This architecture offers decentralization, immutability, auditability, and enhanced availability and reliability.","PeriodicalId":295373,"journal":{"name":"2022 7th International Conference on Smart and Sustainable Technologies (SpliTech)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133708883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bagging Ensemble Classifier for Predicting Lightning Flashovers on Distribution Lines","authors":"P. Sarajcev","doi":"10.23919/SpliTech55088.2022.9854317","DOIUrl":"https://doi.org/10.23919/SpliTech55088.2022.9854317","url":null,"abstract":"This paper introduces a bagging ensemble classifier, built from support vector machines (SVM), for predicting lightning flashovers on overhead distribution lines (OHL). Support vectors from the underlying SVM give rise to the so-called curve of limiting parameters (CLP), which features prominently in the statistical method of insulation coordination. Proposed machine learning-based approach enables a straightforward derivation of the line's CLP-from simulations or actual measurements data gathered by the lightning location systems-for its subsequent use in insulation coordination studies. It also facilitates computing the risk of insulation flashover. Both these aspects fully endorse statistical approach to the insulation coordination and flashover performance analysis of OHLs.","PeriodicalId":295373,"journal":{"name":"2022 7th International Conference on Smart and Sustainable Technologies (SpliTech)","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114239638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Blockchain Based Approach for Demand Response Management in Internet of Vehicles","authors":"E. Kapassa, M. Touloupou, Klitos Christodoulou","doi":"10.23919/SpliTech55088.2022.9854344","DOIUrl":"https://doi.org/10.23919/SpliTech55088.2022.9854344","url":null,"abstract":"Electric Vehicles (EVs), as well as the number of applications for their management, are rapidly increasing due to the fact that Internet of Vehicles (IoV) becomes more informative and industrialized. According to the literature, IoV requires decentralization towards the energy Demand Response (DR) management, with secure energy trading, efficient charging scheduling, and incentives for making the drivers to participate. Blockchain and Distributed Ledger Technologies (DLTs) can be used to enable a foundational environment to support DR management. However, and to the best of our knowledge, none of the existing research works discussed in the literature adopts a holistic approach to address them. As such there is a demand for exploring a unified blockchain-based framework for distributed DR management. Therefore, the aim of this work is focused on the blockchain adoption in IoV-assisted smart cities. More specifically, we propose a blockchain based approach, to be used for building a secure and user-centric DR management framework. Our proposition aims to address the DRP in IoV through charging scheduling based on the generation of EV driving profiles, and optimal Vehicle-to-Vehicle/Grid (V2V | V2G) energy trading.","PeriodicalId":295373,"journal":{"name":"2022 7th International Conference on Smart and Sustainable Technologies (SpliTech)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114602309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Performance analysis of SQL Prepared Statements in CRUD operations","authors":"Tomislav Seser, V. Pleština, Frane Marjanica","doi":"10.23919/SpliTech55088.2022.9854303","DOIUrl":"https://doi.org/10.23919/SpliTech55088.2022.9854303","url":null,"abstract":"In a web application, communication between the application and the database server is one of the most resource intensive operations which therefore requires optimization. Database optimization is a challenging task where even a minor change can have a big impact on overall application performance. Prepared statements bring two main advantages: security and consistency. They are often considered to also have a performance advantage but, in this paper, it will be shown how prepared statements can have decremental performance impact, and when they should and should not be used if resources and performance is a concern.","PeriodicalId":295373,"journal":{"name":"2022 7th International Conference on Smart and Sustainable Technologies (SpliTech)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124806151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Francesco Nocera, Sergio Abascia, M. Fiore, A. Shah, M. Mongiello, Eugenio Di Sciascio, G. Acciani
{"title":"Cyber-Attack Mitigation in Cloud-Fog Environment Using an Ensemble Machine Learning Model","authors":"Francesco Nocera, Sergio Abascia, M. Fiore, A. Shah, M. Mongiello, Eugenio Di Sciascio, G. Acciani","doi":"10.23919/SpliTech55088.2022.9854372","DOIUrl":"https://doi.org/10.23919/SpliTech55088.2022.9854372","url":null,"abstract":"Since the use of Cloud technologies has spread exponentially in the world, the use of Network intrusion detection system has become a field of vital importance in Cyber Security: with the endless growth of network traffic and the spread of new methods of attack, this type of technology has become a must that cloud environments cannot afford to ignore. The proposed approach of this work is based on machine learning and anomaly detection techniques highlights how the deep learning approach turns out to be the best weapon to identify and isolate this type of malicious attacks, surpassing in precision and accuracy approaches of pattern recognition and anomaly detection approaches more traditional like Support Vector Machine (SVM) or Decision Tree (DT). The obtained values of accuracy, precision and recall let us understand on which classes the model is able to be further improved, increasing even more already excellent values of predictions and instead underline the classes in which the model need of being improved with training data more distributed in classes that are performing below the average.","PeriodicalId":295373,"journal":{"name":"2022 7th International Conference on Smart and Sustainable Technologies (SpliTech)","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122098581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Basis Pursuit and Linear Programming Equivalence: A Performance Comparison in Sparse Signal Recovery","authors":"B. Tausiesakul","doi":"10.23919/SpliTech55088.2022.9854240","DOIUrl":"https://doi.org/10.23919/SpliTech55088.2022.9854240","url":null,"abstract":"Basis pursuit (BP) with $ell_{1}$-norm criterion received much attention in the past. One of its obvious applications is the discrete-time sparse signal acquisition. In this work, two alternative forms of the BP optimization are presented. Both are intended to perform the same task as the BP but are expressed as linear programming (LP) frameworks. The performance of the LP expressions, which are equivalent to the BP, is observed and then compared to that given by the typical BP. It is found that the error performance of the equivalent BP methods in terms of LP is the same as that of the BP algorithm. One of the BP-equivalent LP problems takes the same computational time as the BP, while another lasts longer in computation. In the same manner, the first BP-equivalent LP problem consumes nearly the same amount of required memory as the BP, whereas another occupies significantly more memory space during the computation.","PeriodicalId":295373,"journal":{"name":"2022 7th International Conference on Smart and Sustainable Technologies (SpliTech)","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129935235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}