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Utilizing Heuristics and Metaheuristics for Solving the Set Covering Problem 利用启发式方法和元启发式方法解决集合覆盖问题
U.Porto Journal of Engineering Pub Date : 2024-07-10 DOI: 10.24840/2183-6493_0010-001_002474
Lourenço Sousa de Pinho
{"title":"Utilizing Heuristics and Metaheuristics for Solving the Set Covering Problem","authors":"Lourenço Sousa de Pinho","doi":"10.24840/2183-6493_0010-001_002474","DOIUrl":"https://doi.org/10.24840/2183-6493_0010-001_002474","url":null,"abstract":"A basic combinatorial optimization problem, the Set Covering Problem (SCP) finds extensive use in computer science, operations research, and logistics, among other domains. The SCP’s goal is to determine the smallest number of subsets, or sets, needed to cover every element precisely once given a finite set of items and a collection of subsets of these elements. Numerous practical uses for the SCP exist, such as crew scheduling, truck routing, and facility locating.\u0000This paper focuses on obtaining feasible solutions, applying to the obtained solutions constructive heuristics (CH), followed by a redundancy elimination procedure to remove unnecessary sets. To further optimize the quality of the solution, a local search method is also implemented based on the First and Best improvement algorithms. Additionally, the Greedy Randomized Adaptive Search Procedure (GRASP) and Variable Neighborhood Search (VNS) metaheuristics are designed and implemented. Each implemented heuristic underwent testing across 42 instances, with the average deviation from the optimal solution calculated for each instance. The GRASP heuristic demonstrated the most favorable performance, achieving a maximum deviation of 2.26% from the optimal solution, while the VNS approach yielded a maximum deviation of 11.46% from the optimal solution at its best.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"17 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141660948","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}
引用次数: 0
A Comparative Analysis of Machine Learning Models in News Categorization 新闻分类中机器学习模型的比较分析
U.Porto Journal of Engineering Pub Date : 2024-07-10 DOI: 10.24840/2183-6493_0010-003_002464
M. H. Zolfagharnasab, Siavash Damari
{"title":"A Comparative Analysis of Machine Learning Models in News Categorization","authors":"M. H. Zolfagharnasab, Siavash Damari","doi":"10.24840/2183-6493_0010-003_002464","DOIUrl":"https://doi.org/10.24840/2183-6493_0010-003_002464","url":null,"abstract":"The constant stream of news nowadays highlights the necessity for meticulous assessment to ensure that the information accurately reaches its intended audience with the least amount of delay least delay. Despite the flexibility and efficiency of Deep Learning (DL) models, their intricate training and substantial resource demands pose significant challenges for their deployment in real-time applications. In this regard, this study evaluates the performance of resource-efficient Machine Learning (ML) techniques – Multinomial Naive Bayes (MNB), Random Forest (RF), Support Vector Machine (SVM), and Logistic Regression (LR) – in categorizing news. Based on the results, all the evaluated models attain a commendable level of accuracy in news categorization. Notably, the SVM excels, achieving an accuracy rate of 98% and a mean squared error of 0.28. This performance exemplifies the robust effectiveness of classical ML models in the categorization of news, particularly when enhanced by a suitably tailored preprocessing pipeline.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"18 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141661626","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}
引用次数: 0
Pompan: A bread production alternative using apple pomace Pompan：利用苹果渣生产面包的替代品
U.Porto Journal of Engineering Pub Date : 2024-04-18 DOI: 10.24840/2183-6493_0010-002_002611
Beatriz Coelho, Inês Oliveira, Isabel Mota, João Nunes, Sofia Coelho, Tiago Mendes
{"title":"Pompan: A bread production alternative using apple pomace","authors":"Beatriz Coelho, Inês Oliveira, Isabel Mota, João Nunes, Sofia Coelho, Tiago Mendes","doi":"10.24840/2183-6493_0010-002_002611","DOIUrl":"https://doi.org/10.24840/2183-6493_0010-002_002611","url":null,"abstract":"This work consists of developing a product that uses apple leftovers. The product selected was bread baked with a flour mixture of 5% (by mass) apple flour to wheat flour. Besides providing an easy-to-use solution for leftovers, this mixture also provides a higher fiber content to the food. After the process was designed, it was concluded that producing 5.4 million breads per year with about 23 tons of apple pomace was possible. In the end, the economic analysis was done, and the process should return a profit at the beginning of the second year, having an NPV of 0.88 M€, an IRR of 27.8% and a payback time of almost 4 years.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":" 23","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140690104","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}
引用次数: 0
PHArmed: A Biological Process for PHA Production from Apple Waste Residues PHArmed：利用苹果废渣生产 PHA 的生物工艺
U.Porto Journal of Engineering Pub Date : 2024-04-17 DOI: 10.24840/2183-6493_0010-002_002577
Maria Teresa Oliveira, José Francisco Marques, Markus Driller, Rita Sousa Branco, Sofia Pinto, Rita Barros
{"title":"PHArmed: A Biological Process for PHA Production from Apple Waste Residues","authors":"Maria Teresa Oliveira, José Francisco Marques, Markus Driller, Rita Sousa Branco, Sofia Pinto, Rita Barros","doi":"10.24840/2183-6493_0010-002_002577","DOIUrl":"https://doi.org/10.24840/2183-6493_0010-002_002577","url":null,"abstract":"PHArmed is an innovative Portuguese company responsible for producing PHA in its rawest form, using renewable carbon sources from apple residues. With the increasing environmental urge to find alternatives to regular plastic and an existing expensive way of producing PHA, PHArmed solves both issues with a biodegradable and cheaper product, with biocompatible properties that make it viable for both medical and pharmaceutical industries. Using apple waste from other companies reduces production costs and helps solve the issue regarding waste treatment. After a complete definition of the manufacturing process, the industrial plant would be installed in Pombal, near two large apple waste-producing companies, with a work team of 15 operators. An economic assessment was performed, and an initial 11.8 M€ investment was estimated for the first year. The project was shown to be economically viable and capable of generating a financial surplus, reaching a break-even point after six years.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":" 47","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140691033","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}
引用次数: 0
Editoral 出版商
U.Porto Journal of Engineering Pub Date : 2024-04-17 DOI: 10.24840/2183-6493_0010-002_002615
Cláudia Gomes Silva, Y. Manrique, Ricardo Santos
{"title":"Editoral","authors":"Cláudia Gomes Silva, Y. Manrique, Ricardo Santos","doi":"10.24840/2183-6493_0010-002_002615","DOIUrl":"https://doi.org/10.24840/2183-6493_0010-002_002615","url":null,"abstract":"Product Engineering is an essential component in engineering training. The jobs in the Chemical Engineering sector have been evolving from commodities production to product development, particularly in countries such as Portugal, where the scale of production is more adapted to customized or medium-sized series than mass production. So, in 2009, the Master’s in Chemical Engineering Programme at the Faculty of Engineering of the University of Porto (FEUP) started a course on Product Engineering. In 2022, a special issue in the U.Porto Journal of Engineering was published, which included a series of selected works developed within the Product Engineering course at FEUP (Silva et al. 2022). The same methodology for product development laid in four cornerstones was kept in this course:\u0000\u0000Identification of market NEEDS;\u0000Coming up with several technical solutions to meet those NEEDS (IDEAS);\u0000The process of screening a small set of the best IDEAS (SELECTION);\u0000The study of the implementation of IDEAS considers time to market, industrial process design, regulation, Intellectual Property Rights, and economic analysis (MANUFACTURE).\u0000\u0000In the last edition of the Product Engineering course (2023-24), integrated process simulation tools, namely Super Pro Designer and ASPEN, were used by the students. This enabled the students to apply know-how acquired during the Chemical Engineering course and to obtain a more accurate design of the processes and CAPEX and OPEX estimation. Thus, this second Special Issue includes some of the works already incorporating this new feature.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"43 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140693941","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}
引用次数: 0
Can a mathematical model describe the main problems of the modern world? 数学模型能否描述现代世界的主要问题？
U.Porto Journal of Engineering Pub Date : 2024-04-11 DOI: 10.24840/2183-6493_0010-001_002344
Ioannis Rizos, Nikolaos Gkrekas
{"title":"Can a mathematical model describe the main problems of the modern world?","authors":"Ioannis Rizos, Nikolaos Gkrekas","doi":"10.24840/2183-6493_0010-001_002344","DOIUrl":"https://doi.org/10.24840/2183-6493_0010-001_002344","url":null,"abstract":"This article focuses on the transformation of current global problems into mathematical data and the drawing of conclusions from the results. After a theoretical introduction that clarifies the philosophy of the above approach and provides an innovative description of the mathematical model concept, a method for describing and analyzing crises is presented, with the goal of measuring its influence on the observable system, whether at the EU, global, or other levels. Converting social issues into quantitative data provides a systematic assessment of the severity of crises and allows for comparisons across different crises and systems. The main conclusion of the article is that a mathematical model, such as the one introduced here, could, to some extent, describe, as a first approach, global problems and their interrelationship, and thus be useful to policy makers.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"22 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140714850","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}
引用次数: 0
Effect of Aging Heat Treatment in an Al-4008 Produced by Liquid Metal Printing 液态金属印刷生产的 Al-4008 中老化热处理的影响
U.Porto Journal of Engineering Pub Date : 2024-02-06 DOI: 10.24840/2183-6493_0010-001_002060
Catarina Ladeiro, Francisca Nunes, Mariana Trindade, Jose M. Costa
{"title":"Effect of Aging Heat Treatment in an Al-4008 Produced by Liquid Metal Printing","authors":"Catarina Ladeiro, Francisca Nunes, Mariana Trindade, Jose M. Costa","doi":"10.24840/2183-6493_0010-001_002060","DOIUrl":"https://doi.org/10.24840/2183-6493_0010-001_002060","url":null,"abstract":"In today's world, additive manufacturing (AM) is one of the most popular technologies and has the potential to revolutionize the manufacturing industry. As one of the most recent advances in this industry, liquid metal printing has a growing value in the engineering field. This study aims to evaluate the effect of two heat treatment conditions in an Al-4008 alloy produced by this technique in the microstructure and mechanical properties. It was concluded that the heat treatment (HT) enhances the Si particle coalescence and Fe-rich intermetallic compound precipitation, increasing the sample hardness significantly (50%). Density analysis showed a slight porosity decrease with HT. Tensile tests indicated heat-treated, same-directionally pulled samples exhibited brittleness compared to as-printed ones, while HT increased both yield strength (245 MPa) and ultimate tensile strength (294 MPa).","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"57 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139801660","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}
引用次数: 0
Effect of Aging Heat Treatment in an Al-4008 Produced by Liquid Metal Printing 液态金属印刷生产的 Al-4008 中老化热处理的影响
U.Porto Journal of Engineering Pub Date : 2024-02-06 DOI: 10.24840/2183-6493_0010-001_002060
Catarina Ladeiro, Francisca Nunes, Mariana Trindade, Jose M. Costa
{"title":"Effect of Aging Heat Treatment in an Al-4008 Produced by Liquid Metal Printing","authors":"Catarina Ladeiro, Francisca Nunes, Mariana Trindade, Jose M. Costa","doi":"10.24840/2183-6493_0010-001_002060","DOIUrl":"https://doi.org/10.24840/2183-6493_0010-001_002060","url":null,"abstract":"In today's world, additive manufacturing (AM) is one of the most popular technologies and has the potential to revolutionize the manufacturing industry. As one of the most recent advances in this industry, liquid metal printing has a growing value in the engineering field. This study aims to evaluate the effect of two heat treatment conditions in an Al-4008 alloy produced by this technique in the microstructure and mechanical properties. It was concluded that the heat treatment (HT) enhances the Si particle coalescence and Fe-rich intermetallic compound precipitation, increasing the sample hardness significantly (50%). Density analysis showed a slight porosity decrease with HT. Tensile tests indicated heat-treated, same-directionally pulled samples exhibited brittleness compared to as-printed ones, while HT increased both yield strength (245 MPa) and ultimate tensile strength (294 MPa).","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"13 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139861230","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}
引用次数: 0
Design and Optimization of a Gripper Clamp 夹具的设计与优化
U.Porto Journal of Engineering Pub Date : 2024-02-02 DOI: 10.24840/2183-6493_0010-001_002059
Mariana Cunha, Sofia Alves, Jose M. Costa
{"title":"Design and Optimization of a Gripper Clamp","authors":"Mariana Cunha, Sofia Alves, Jose M. Costa","doi":"10.24840/2183-6493_0010-001_002059","DOIUrl":"https://doi.org/10.24840/2183-6493_0010-001_002059","url":null,"abstract":"Additive Manufacturing, among the many developing advanced manufacturing technologies, stands out as the one with the greatest potential for changing the distribution of manufacturing, society, and sustainability. To produce sustainable and competitive products, component material and design selection is an essential and critical topic in the industry. The production of parts designed using the Design for Additive Manufacturing methodology (DfAM) has grown in popularity in recent years. Topological optimization can be used as a design tool in the early stages of the design process to meet strength and endurance requirements on a component level. This study explores the topology optimization of a gripper clamp through nTopology and Fusion 360, using AISI 316L stainless steel as material, for possible production through Additive Manufacturing. The final component demonstrated reliable results.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"4 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139811561","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}
引用次数: 0
Design and Optimization of a Gripper Clamp 夹具的设计与优化
U.Porto Journal of Engineering Pub Date : 2024-02-02 DOI: 10.24840/2183-6493_0010-001_002059
Mariana Cunha, Sofia Alves, Jose M. Costa
{"title":"Design and Optimization of a Gripper Clamp","authors":"Mariana Cunha, Sofia Alves, Jose M. Costa","doi":"10.24840/2183-6493_0010-001_002059","DOIUrl":"https://doi.org/10.24840/2183-6493_0010-001_002059","url":null,"abstract":"Additive Manufacturing, among the many developing advanced manufacturing technologies, stands out as the one with the greatest potential for changing the distribution of manufacturing, society, and sustainability. To produce sustainable and competitive products, component material and design selection is an essential and critical topic in the industry. The production of parts designed using the Design for Additive Manufacturing methodology (DfAM) has grown in popularity in recent years. Topological optimization can be used as a design tool in the early stages of the design process to meet strength and endurance requirements on a component level. This study explores the topology optimization of a gripper clamp through nTopology and Fusion 360, using AISI 316L stainless steel as material, for possible production through Additive Manufacturing. The final component demonstrated reliable results.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"42 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139871755","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}
引用次数: 0
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