Pub Date : 2023-10-25DOI: 10.1080/23311916.2023.2273088
Daraje Kaba Gurmessa, Worku Jimma
Stroke presents a formidable global health threat, carrying significant risks and challenges. Timely intervention and improved outcomes hinge on the integration of Explainable Artificial Intelligence (XAI) into medical decision-making. XAI, an evolving field, enhances the transparency of conventional Artificial Intelligence (AI) models. This systematic review addresses key research questions: How is XAI applied in the context of stroke diagnosis? To what extent can XAI elucidate the outputs of machine learning models? Which systematic evaluation methodologies are employed, and what categories of explainable approaches (Model Explanation, Outcome Explanation, Model Inspection) are prevalent We conducted this review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Our search encompassed five databases: Google Scholar, PubMed, IEEE Xplore, ScienceDirect, and Scopus, spanning studies published between January 1988 and June 2023. Various combinations of search terms, including “stroke,” “explainable,” “interpretable,” “machine learning,” “artificial intelligence,” and “XAI,” were employed. This study identified 17 primary studies employing explainable machine learning techniques for stroke diagnosis. Among these studies, 94.1% incorporated XAI for model visualization, and 47.06% employed model inspection. It is noteworthy that none of the studies employed evaluation metrics such as D, R, F, or S to assess the performance of their XAI systems. Furthermore, none evaluated human confidence in utilizing XAI for stroke diagnosis. Explainable Artificial Intelligence serves as a vital tool in enhancing trust among both patients and healthcare providers in the diagnostic process. The effective implementation of systematic evaluation metrics is crucial for harnessing the potential of XAI in improving stroke diagnosis.
{"title":"A comprehensive evaluation of explainable Artificial Intelligence techniques in stroke diagnosis: A systematic review","authors":"Daraje Kaba Gurmessa, Worku Jimma","doi":"10.1080/23311916.2023.2273088","DOIUrl":"https://doi.org/10.1080/23311916.2023.2273088","url":null,"abstract":"Stroke presents a formidable global health threat, carrying significant risks and challenges. Timely intervention and improved outcomes hinge on the integration of Explainable Artificial Intelligence (XAI) into medical decision-making. XAI, an evolving field, enhances the transparency of conventional Artificial Intelligence (AI) models. This systematic review addresses key research questions: How is XAI applied in the context of stroke diagnosis? To what extent can XAI elucidate the outputs of machine learning models? Which systematic evaluation methodologies are employed, and what categories of explainable approaches (Model Explanation, Outcome Explanation, Model Inspection) are prevalent We conducted this review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Our search encompassed five databases: Google Scholar, PubMed, IEEE Xplore, ScienceDirect, and Scopus, spanning studies published between January 1988 and June 2023. Various combinations of search terms, including “stroke,” “explainable,” “interpretable,” “machine learning,” “artificial intelligence,” and “XAI,” were employed. This study identified 17 primary studies employing explainable machine learning techniques for stroke diagnosis. Among these studies, 94.1% incorporated XAI for model visualization, and 47.06% employed model inspection. It is noteworthy that none of the studies employed evaluation metrics such as D, R, F, or S to assess the performance of their XAI systems. Furthermore, none evaluated human confidence in utilizing XAI for stroke diagnosis. Explainable Artificial Intelligence serves as a vital tool in enhancing trust among both patients and healthcare providers in the diagnostic process. The effective implementation of systematic evaluation metrics is crucial for harnessing the potential of XAI in improving stroke diagnosis.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"20 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135167031","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}
Pub Date : 2023-10-25DOI: 10.1080/23311916.2023.2272358
Nachaat Mohamed
{"title":"Current trends in AI and ML for cybersecurity: A state-of-the-art survey","authors":"Nachaat Mohamed","doi":"10.1080/23311916.2023.2272358","DOIUrl":"https://doi.org/10.1080/23311916.2023.2272358","url":null,"abstract":"","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"24 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135168878","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}
Pub Date : 2023-10-24DOI: 10.1080/23311916.2023.2272351
Sooraj Mohan, Augustine B.V. Barboza, P. Dinesha
The quest for energy efficiency systems is gaining momentum in the present-day context due to prevailing environmental and eco nomic compulsions. One of the alternatives available to meet this requirement is to modify the fuel to make it greener and more reasonable. In the present study, an attempt has been made to assess the performance and emissions of a compression ignition (CI) engine fuelled with B20 biodiesel and nano additives. Experiments have been carried out on a ssingle-cylinder CI engine using waste cooking oil-derived biodiesel, B20 and nano-sized biochar and multi-walled carbon nano tubes (MWCNTs). The nano additives were used in concentrations of 20 and 40 ppm to form four fuel variants, and the results relating to performance and emissions were compared. B20 fuel with MWCNT nanoparticles showed better brake thermal efficiency (BTE), brake-specific fuel consumption and reduced HC and carbon monoxide emissions. On the contrary, increased exhaust temperature and a subsequent increase in NOx emissions were recorded. The activated biochar nanoparticles improved the BTE of the engine with a comparatively better removal of NOx. This intricate behaviour of both the carbon nanoparticles reported in this work requires comprehensive optimization studies in the future.
{"title":"Effect of eco-friendly nano additive with green fuel on performance and emissions of a compression ignition engine","authors":"Sooraj Mohan, Augustine B.V. Barboza, P. Dinesha","doi":"10.1080/23311916.2023.2272351","DOIUrl":"https://doi.org/10.1080/23311916.2023.2272351","url":null,"abstract":"The quest for energy efficiency systems is gaining momentum in the present-day context due to prevailing environmental and eco nomic compulsions. One of the alternatives available to meet this requirement is to modify the fuel to make it greener and more reasonable. In the present study, an attempt has been made to assess the performance and emissions of a compression ignition (CI) engine fuelled with B20 biodiesel and nano additives. Experiments have been carried out on a ssingle-cylinder CI engine using waste cooking oil-derived biodiesel, B20 and nano-sized biochar and multi-walled carbon nano tubes (MWCNTs). The nano additives were used in concentrations of 20 and 40 ppm to form four fuel variants, and the results relating to performance and emissions were compared. B20 fuel with MWCNT nanoparticles showed better brake thermal efficiency (BTE), brake-specific fuel consumption and reduced HC and carbon monoxide emissions. On the contrary, increased exhaust temperature and a subsequent increase in NOx emissions were recorded. The activated biochar nanoparticles improved the BTE of the engine with a comparatively better removal of NOx. This intricate behaviour of both the carbon nanoparticles reported in this work requires comprehensive optimization studies in the future.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"37 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135315544","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}
Pub Date : 2023-10-19DOI: 10.1080/23311916.2023.2269651
Isra M. Al-Shdaifat, Laith M. Obeidat, Shouib Nouh Mabdeh, Loai Alzoubi, Sukina H. Al-Khazaleh
This study aims to investigate the effectiveness of video-based feedback in enhancing learning outcomes for undergraduate students in the field of architectural engineering. The research addresses a gap in the existing literature by exploring the impact of video feedback on students with different learning styles. The study involved 26 participants from Al al-Bayt University, who were enrolled in a four-week summer workshop. Participants’ learning styles were identified using Kolb’s Learning Style Inventory, encompassing divergent, assimilator, convergent, and accommodator styles. The study employed a quasi-experimental design, with participants assigned to two groups: a video feedback group (experimental group) and an in-person feedback group (control group). The video feedback group received video-based feedback on their assignments during phase 2, while the in-person feedback group received traditional face-to-face feedback. Performance scores and perceptions of feedback quality were analyzed using a formative feedback perception scale. The results revealed that video-based feedback significantly influenced feedback development and understandability throughout the design process. Statistical analysis demonstrated significant differences in performance scores between the video feedback group and the in-person feedback group. The findings of this study have practical implications for educators and instructional designers in architectural design education. Incorporating video-based feedback into teaching practices can enhance learning outcomes and improve the overall quality of feedback provided to students. The study contributes to the existing body of knowledge by shedding light on the effectiveness of video-based feedback in the context of architectural engineering education.
本研究旨在探讨基于视频的反馈在提高建筑工程专业本科生学习成果方面的有效性。本研究通过探讨视频反馈对不同学习风格学生的影响，填补了现有文献的空白。这项研究涉及来自Al Al - bayt大学的26名参与者，他们参加了为期四周的夏季研讨会。使用科尔布学习风格量表来确定参与者的学习风格，包括发散型、同化型、收敛型和适应型。该研究采用了准实验设计，参与者被分为两组:视频反馈组(实验组)和面对面反馈组(对照组)。在第二阶段，视频反馈组收到了基于视频的作业反馈，而面对面反馈组收到了传统的面对面反馈。使用形成性反馈感知量表分析绩效得分和反馈质量感知。结果显示，基于视频的反馈在整个设计过程中显著影响了反馈的发展和可理解性。统计分析表明，视频反馈组和现场反馈组在表现得分上存在显著差异。本研究结果对建筑设计教育的教育者和教学设计师具有实际意义。将基于视频的反馈纳入教学实践可以提高学习效果，并提高提供给学生的反馈的整体质量。该研究通过揭示基于视频的反馈在建筑工程教育背景下的有效性，为现有的知识体系做出了贡献。
{"title":"Integrating video feedback into architectural design education to engage diverse learning styles","authors":"Isra M. Al-Shdaifat, Laith M. Obeidat, Shouib Nouh Mabdeh, Loai Alzoubi, Sukina H. Al-Khazaleh","doi":"10.1080/23311916.2023.2269651","DOIUrl":"https://doi.org/10.1080/23311916.2023.2269651","url":null,"abstract":"This study aims to investigate the effectiveness of video-based feedback in enhancing learning outcomes for undergraduate students in the field of architectural engineering. The research addresses a gap in the existing literature by exploring the impact of video feedback on students with different learning styles. The study involved 26 participants from Al al-Bayt University, who were enrolled in a four-week summer workshop. Participants’ learning styles were identified using Kolb’s Learning Style Inventory, encompassing divergent, assimilator, convergent, and accommodator styles. The study employed a quasi-experimental design, with participants assigned to two groups: a video feedback group (experimental group) and an in-person feedback group (control group). The video feedback group received video-based feedback on their assignments during phase 2, while the in-person feedback group received traditional face-to-face feedback. Performance scores and perceptions of feedback quality were analyzed using a formative feedback perception scale. The results revealed that video-based feedback significantly influenced feedback development and understandability throughout the design process. Statistical analysis demonstrated significant differences in performance scores between the video feedback group and the in-person feedback group. The findings of this study have practical implications for educators and instructional designers in architectural design education. Incorporating video-based feedback into teaching practices can enhance learning outcomes and improve the overall quality of feedback provided to students. The study contributes to the existing body of knowledge by shedding light on the effectiveness of video-based feedback in the context of architectural engineering education.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135778927","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}
Pub Date : 2023-10-18DOI: 10.1080/23311916.2023.2269640
Rawaa Q. Aljbouri, Amjad H. Albayati
Warm mix asphalt (WMA) has gained significant interest recently as a more sustainable and environmentally friendly alternative to conventional hot mix asphalt (HMA). WMA is produced at lower temperatures, reducing energy consumption and greenhouse gas emissions. However, there is an ongoing need to improve the durability of WMA to satisfy the expanding demands of modern road infrastructure. Nanomaterials that possess unique characteristics of high surface area and reactivity could serve as promising additives for improving the performance of WMA. This research aims to investigate the effect of four nanomaterial types on the Marshall properties and durability of warm mix asphalt (WMA). These types are; nano silicaNS, nano carbonate calcium NCC, nano clayNC, and nanoplatelets NP. For each type of Nanomaterial, three contents are tried as follows; NS(1%, 3%, and 5%), NCC(2%, 4%, and 6%), NC(3%, 5%, and 7%), and NP(2%, 4%, and 6%) by weight of asphalt cement. Following the Marshall mix design method, the optimum asphalt cement content is determined; thereafter the optimum dosage for each nanomaterial is obtained based on the highest Marshall stability value. The durability of the control mix (no nanomaterial) and modified mixtures have been compared based on moisture damage, resilient modulus, and permanent deformation. These properties are evaluated using indirect tensile strengthITS and uniaxial repeated load tests. The findings of this research emphasize the potential of nanomaterials to improve the Marshall properties and the durability of WMA significantly. Also, the results showed that using nanomaterials to construct asphalt concrete surface course extended the service life of pavement structures. Compared to CM, modifying asphalt concrete by one of the nanomaterials, NC, NS, NCC, and NP, improved the design life by 59.6, 43.1, 24.4, and 12.2%, respectively. However, the improvement rate for each property depends on the nanomaterial dosage and type. Therefore, this work provides a basis for producing more durable and sustainable paving mixtures using nanomaterials to offer better resistance to distress.
{"title":"Investigating the effect of nanomaterials on the Marshall properties and durability of warm mix asphalt","authors":"Rawaa Q. Aljbouri, Amjad H. Albayati","doi":"10.1080/23311916.2023.2269640","DOIUrl":"https://doi.org/10.1080/23311916.2023.2269640","url":null,"abstract":"Warm mix asphalt (WMA) has gained significant interest recently as a more sustainable and environmentally friendly alternative to conventional hot mix asphalt (HMA). WMA is produced at lower temperatures, reducing energy consumption and greenhouse gas emissions. However, there is an ongoing need to improve the durability of WMA to satisfy the expanding demands of modern road infrastructure. Nanomaterials that possess unique characteristics of high surface area and reactivity could serve as promising additives for improving the performance of WMA. This research aims to investigate the effect of four nanomaterial types on the Marshall properties and durability of warm mix asphalt (WMA). These types are; nano silicaNS, nano carbonate calcium NCC, nano clayNC, and nanoplatelets NP. For each type of Nanomaterial, three contents are tried as follows; NS(1%, 3%, and 5%), NCC(2%, 4%, and 6%), NC(3%, 5%, and 7%), and NP(2%, 4%, and 6%) by weight of asphalt cement. Following the Marshall mix design method, the optimum asphalt cement content is determined; thereafter the optimum dosage for each nanomaterial is obtained based on the highest Marshall stability value. The durability of the control mix (no nanomaterial) and modified mixtures have been compared based on moisture damage, resilient modulus, and permanent deformation. These properties are evaluated using indirect tensile strengthITS and uniaxial repeated load tests. The findings of this research emphasize the potential of nanomaterials to improve the Marshall properties and the durability of WMA significantly. Also, the results showed that using nanomaterials to construct asphalt concrete surface course extended the service life of pavement structures. Compared to CM, modifying asphalt concrete by one of the nanomaterials, NC, NS, NCC, and NP, improved the design life by 59.6, 43.1, 24.4, and 12.2%, respectively. However, the improvement rate for each property depends on the nanomaterial dosage and type. Therefore, this work provides a basis for producing more durable and sustainable paving mixtures using nanomaterials to offer better resistance to distress.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135888010","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}
Pub Date : 2023-10-16DOI: 10.1080/23311916.2023.2269656
G.H. Coffie, S.K.F. Cudjoe
The development of cost overrun prediction models using data mining techniques has considerably increased in recent years. Estimating the final cost of construction projects is essential during the contract award stage of the building process. Projects variables from archival data are important in developing prediction models. This research examines the effectiveness of support vector machines in predicting construction project cost overruns using data from archival records.The independent variables, like number of stories, gross floor area, change in scope, contract type, provisional sum, tendering type, and initial contract sum, were extracted from historical records. In this study, SVM models using linear, RBF, and polynomial kernel functions demonstrated that SVM using linear and polynomial kernel techniques were used in this research. This study looks at how well data mining tools forecast cost overruns in building projects using information from historical records.The results revealed that the linear kernel SVM model could produce accurate construction cost predictions with 0.99 R2, 0.099 RMSE, 0.05 MAE, 0.278 MAPE, and 0.01 MSE on the accuracy test data. When considered collectively, it is clear that gross floor space, story count, tendering method, and scope modification are reliable indicators of cost overruns in the construction sector.The created SVM model can be applied as a cost-estimating tool to predict potential cost overruns for Ghanaian construction projects.
{"title":"Toward predictive modelling of construction cost overruns using support vector machine techniques","authors":"G.H. Coffie, S.K.F. Cudjoe","doi":"10.1080/23311916.2023.2269656","DOIUrl":"https://doi.org/10.1080/23311916.2023.2269656","url":null,"abstract":"The development of cost overrun prediction models using data mining techniques has considerably increased in recent years. Estimating the final cost of construction projects is essential during the contract award stage of the building process. Projects variables from archival data are important in developing prediction models. This research examines the effectiveness of support vector machines in predicting construction project cost overruns using data from archival records.The independent variables, like number of stories, gross floor area, change in scope, contract type, provisional sum, tendering type, and initial contract sum, were extracted from historical records. In this study, SVM models using linear, RBF, and polynomial kernel functions demonstrated that SVM using linear and polynomial kernel techniques were used in this research. This study looks at how well data mining tools forecast cost overruns in building projects using information from historical records.The results revealed that the linear kernel SVM model could produce accurate construction cost predictions with 0.99 R2, 0.099 RMSE, 0.05 MAE, 0.278 MAPE, and 0.01 MSE on the accuracy test data. When considered collectively, it is clear that gross floor space, story count, tendering method, and scope modification are reliable indicators of cost overruns in the construction sector.The created SVM model can be applied as a cost-estimating tool to predict potential cost overruns for Ghanaian construction projects.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136112467","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}
Pub Date : 2023-10-12DOI: 10.1080/23311916.2023.2264060
Van Tron Tran, Minh Huy Le, Minh Thai Vo, Quoc Trung Le, Van Huong Hoang, Ngoc-Thien Tran, Van-Thuc Nguyen, Thi-Anh-Tuyet Nguyen, Hoai Nam Nguyen, Van Thanh Tien Nguyen, Thanh Tan Nguyen
Electrical discharge machining (EDM) is a highly regarded method for producing ultra-precise mechanical parts. In this study, the process parameters of die-sinking EDM using copper electrodes and American Iron and Steel Institute (AISI) P20 tool steel workpieces are optimized for various output responses. The study surveys three input parameters, including Current (I), Pulse on Time (Ton), and Pulse Off Time (Toff). Some statistical methods, such as Taguchi and Analysis of Variance (ANOVA), are applied to find the optimal set of parameters for the output responses, consisting of Material Removal Rate (MRR), Electrode Wear Rate (EWR), and Surface Roughness (SR), and determine the most influential input factor. With the L9 Orthogonal Array (OA), the analytical results demonstrate the optimal parameter set for MRR is I = 6 A, Ton = 120 µs, and Toff = 30 µs, while those optimal values for EWR and SR are I = 2 A, Ton = 120 µs, and Toff = 90 µs and I = 2 A, Ton = 60 µs, and Toff = 30 µs, respectively. The study also indicates that input factor I has the most effect on the output responses, followed by Ton and Toff. Moreover, Grey relational analysis in the Taguchi method is also employed for multi-response optimization. The optimal parameter set for the three output factors is I = 6 A, Ton = 120 µs, and Toff = 60 µs, respectively. In this research, the microstructure and recast layer of the machined surfaces are investigated using optical microscopy as well.
电火花加工(EDM)是一种备受推崇的生产超精密机械零件的方法。在本研究中，针对不同的输出响应，对铜电极和美国钢铁协会(AISI) P20工具钢工件的模压电火花加工工艺参数进行了优化。该研究调查了三个输入参数，包括电流(I)，脉冲接通时间(Ton)和脉冲关闭时间(Toff)。采用田口法(Taguchi)和方差分析(ANOVA)等统计方法寻找输出响应的最优参数集，包括材料去除率(MRR)、电极磨损率(EWR)和表面粗糙度(SR)，并确定影响最大的输入因素。利用L9正交阵列(OA)分析结果表明，MRR的最优参数设置为I = 6 A, Ton = 120µs, Toff = 30µs; EWR和SR的最优参数设置分别为I = 2 A, Ton = 120µs, Toff = 90µs和I = 2 A, Ton = 60µs, Toff = 30µs。研究还表明，输入因子I对输出响应的影响最大，其次是Ton和Toff。此外，还采用田口法中的灰色关联分析进行多响应优化。三个输出因子的最佳参数设置分别为I = 6 A, Ton = 120µs, Toff = 60µs。在本研究中，利用光学显微镜对加工表面的显微组织和重铸层进行了研究。
{"title":"Optimization design for die-sinking EDM process parameters employing effective intelligent method","authors":"Van Tron Tran, Minh Huy Le, Minh Thai Vo, Quoc Trung Le, Van Huong Hoang, Ngoc-Thien Tran, Van-Thuc Nguyen, Thi-Anh-Tuyet Nguyen, Hoai Nam Nguyen, Van Thanh Tien Nguyen, Thanh Tan Nguyen","doi":"10.1080/23311916.2023.2264060","DOIUrl":"https://doi.org/10.1080/23311916.2023.2264060","url":null,"abstract":"Electrical discharge machining (EDM) is a highly regarded method for producing ultra-precise mechanical parts. In this study, the process parameters of die-sinking EDM using copper electrodes and American Iron and Steel Institute (AISI) P20 tool steel workpieces are optimized for various output responses. The study surveys three input parameters, including Current (I), Pulse on Time (Ton), and Pulse Off Time (Toff). Some statistical methods, such as Taguchi and Analysis of Variance (ANOVA), are applied to find the optimal set of parameters for the output responses, consisting of Material Removal Rate (MRR), Electrode Wear Rate (EWR), and Surface Roughness (SR), and determine the most influential input factor. With the L9 Orthogonal Array (OA), the analytical results demonstrate the optimal parameter set for MRR is I = 6 A, Ton = 120 µs, and Toff = 30 µs, while those optimal values for EWR and SR are I = 2 A, Ton = 120 µs, and Toff = 90 µs and I = 2 A, Ton = 60 µs, and Toff = 30 µs, respectively. The study also indicates that input factor I has the most effect on the output responses, followed by Ton and Toff. Moreover, Grey relational analysis in the Taguchi method is also employed for multi-response optimization. The optimal parameter set for the three output factors is I = 6 A, Ton = 120 µs, and Toff = 60 µs, respectively. In this research, the microstructure and recast layer of the machined surfaces are investigated using optical microscopy as well.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136012835","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}
The purpose of this study is to develop a performance measurement model based on maturity dimensions or criteria and KPIs identified through an extensive literature review. Using the Decision-Making Trial and Evaluation Laboratory (DEMATEL) method, a maturity model is developed by analyzing 12 criteria/dimensions and 51 KPIs. The importance of each criterion and KPI is analysed through focus group discussions with experts. A fuzzy method is used to resolve the fuzziness and uncertainty of the expert judgments. The fuzzy DEMATEL method is used to analyse the data, and the values of R+C and R-C are computed. In order to visualize the complex relationships, identify the most important criteria of building maintenance and analyse their mutual influence, a cause-effect diagram is created by mapping all sets of coordinates. Accordingly, C8 (culture and leadership), C1 (maintenance policy and strategy), C6 (design life), and C5 (maintenance information management) are assigned to the cause group. These four criteria are identified as the most critical criteria because they can influence the remaining criteria categorized in the effect group. For negative values of (R-C), C2, C3, C4, C7, C9, C10, C11, and C12 are categorized in the effect group. A five-level hierarchical model was developed to measure maturity performance based on the weighted average of the criteria and KPIs of the fuzzy DEMATE outcomes. The current model covers multiple measurement dimensions/perspectives as a measurement criterion for building maintenance maturity. The model is important for decision makers to identify weaknesses and strengths and incrementally improve the weaknesses in a continuous improvement approach. The new model can help decision makers determine the current state of maintenance maturity and plan actions to improve efficiency and effectiveness to create sustainable and productive building assets.
{"title":"Maturity model for evaluating building maintenance practice: A fuzzy-DEMATEL approach","authors":"Muluken Tilahun Desbalo, Asregedew Kassa Woldesenbet, Zewdu Seblework Tafesse, Hans-Joachim Bargstadt, Mitiku Damtie Yehualaw","doi":"10.1080/23311916.2023.2261226","DOIUrl":"https://doi.org/10.1080/23311916.2023.2261226","url":null,"abstract":"The purpose of this study is to develop a performance measurement model based on maturity dimensions or criteria and KPIs identified through an extensive literature review. Using the Decision-Making Trial and Evaluation Laboratory (DEMATEL) method, a maturity model is developed by analyzing 12 criteria/dimensions and 51 KPIs. The importance of each criterion and KPI is analysed through focus group discussions with experts. A fuzzy method is used to resolve the fuzziness and uncertainty of the expert judgments. The fuzzy DEMATEL method is used to analyse the data, and the values of R+C and R-C are computed. In order to visualize the complex relationships, identify the most important criteria of building maintenance and analyse their mutual influence, a cause-effect diagram is created by mapping all sets of coordinates. Accordingly, C8 (culture and leadership), C1 (maintenance policy and strategy), C6 (design life), and C5 (maintenance information management) are assigned to the cause group. These four criteria are identified as the most critical criteria because they can influence the remaining criteria categorized in the effect group. For negative values of (R-C), C2, C3, C4, C7, C9, C10, C11, and C12 are categorized in the effect group. A five-level hierarchical model was developed to measure maturity performance based on the weighted average of the criteria and KPIs of the fuzzy DEMATE outcomes. The current model covers multiple measurement dimensions/perspectives as a measurement criterion for building maintenance maturity. The model is important for decision makers to identify weaknesses and strengths and incrementally improve the weaknesses in a continuous improvement approach. The new model can help decision makers determine the current state of maintenance maturity and plan actions to improve efficiency and effectiveness to create sustainable and productive building assets.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136295398","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}
Resistance spot welding (RSW) is one of the welding technologies that uses the force and heat generated by resistance to the flow of electricity to join metal surfaces. The goal of this research is to investigate the mechanical behavior of RSW,the welding parameters of sheet metal-covered aluminum spot-welded junctions, and finally to verify the micro-hardness of the weld structure. RSW process is a complicated operation that combines electrical, thermal, and mechanical processes. Moreover, serious complications are observed when the weld material is aluminum, because it is a very soft metal and difficult to weld as compared to other metals, Hence, we used mild steel as a cover on both sides and easily did the RSW. Aluminum (Al) thickness, cover sheet metal thickness, and overall welding time achieved relative impacts of 3.890%, 3.250%, and 84.390%, respectively. The percentage impacts of aluminum (Al) thickness, weld cover sheet metal thickness, and welding time in the deformation scenario are 1.171%, 8.731%, and 80.881%, respectively. The percentage impacts of aluminum thickness, cover sheet metal thickness, and welding time duration on temperature are 9.960%, 87.820%, and 1.660%, respectively. The thickness of the cover mild steel sheet is the second-most important factor, next to welding time. Validation results of the two critical weld constraints (welding temperature and welding time) agrees with the experimental results. In addition, the welding temperature response has a percent error of 10.620% due to materials characteristics and the impact of additional welding process constraints.
{"title":"Experimental and finite element investigation of resistance spot welding of mild steel sheet covered aluminum alloy, AA 2017","authors":"Tewodros Terefe, Besufekad Negash, Ayodeji Olalekan Salau, Amberbir Wondimu","doi":"10.1080/23311916.2023.2265236","DOIUrl":"https://doi.org/10.1080/23311916.2023.2265236","url":null,"abstract":"Resistance spot welding (RSW) is one of the welding technologies that uses the force and heat generated by resistance to the flow of electricity to join metal surfaces. The goal of this research is to investigate the mechanical behavior of RSW,the welding parameters of sheet metal-covered aluminum spot-welded junctions, and finally to verify the micro-hardness of the weld structure. RSW process is a complicated operation that combines electrical, thermal, and mechanical processes. Moreover, serious complications are observed when the weld material is aluminum, because it is a very soft metal and difficult to weld as compared to other metals, Hence, we used mild steel as a cover on both sides and easily did the RSW. Aluminum (Al) thickness, cover sheet metal thickness, and overall welding time achieved relative impacts of 3.890%, 3.250%, and 84.390%, respectively. The percentage impacts of aluminum (Al) thickness, weld cover sheet metal thickness, and welding time in the deformation scenario are 1.171%, 8.731%, and 80.881%, respectively. The percentage impacts of aluminum thickness, cover sheet metal thickness, and welding time duration on temperature are 9.960%, 87.820%, and 1.660%, respectively. The thickness of the cover mild steel sheet is the second-most important factor, next to welding time. Validation results of the two critical weld constraints (welding temperature and welding time) agrees with the experimental results. In addition, the welding temperature response has a percent error of 10.620% due to materials characteristics and the impact of additional welding process constraints.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136358663","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}
Pub Date : 2023-10-09DOI: 10.1080/23311916.2023.2265632
Nicia Guillén-Yparrea, Felipe Hernández-Rodríguez, María Soledad Ramírez-Montoya
This work seeks to analyze the scientific evidence of the last five years and investigate the behavioral trends of virtual platforms and simulations for learning and skills development. By conducting a systematic literature review, utilizing the SciVal tool, and assessing statistical findings, we aim to establish a framework for the current status of the subject and identify the primary trends and applications of the strategies employed. Among the most relevant findings were the increase in registered users worldwide in 2021 due to the pandemic and the growth of courses available on virtual platforms such as Coursera and edEx. The most significant themes, both in indexed scholarly publications and in recent citations, were in computer science and education, showing how applications of educational technology have broken the paradigm of traditional education. Statistical studies also provide information regarding projections for new users in the next five years, owing to the popularity and effectiveness of these tools. This article summarizes the most significant information from sources such as Scopus, Web of Science, SciVal, and Statistical Sources. It presents a clear overview of the experimentation and use of virtual platforms and simulations for learning and competency development in higher education, highlighting key concepts and providing guidelines for future applications.
这项工作旨在分析过去五年的科学证据，并调查用于学习和技能发展的虚拟平台和模拟的行为趋势。通过进行系统的文献综述，利用SciVal工具，并评估统计结果，我们的目标是为该主题的现状建立一个框架，并确定所采用策略的主要趋势和应用。其中最相关的发现是，受疫情影响，2021年全球注册用户增加，以及Coursera和edEx等虚拟平台上的课程增加。在有索引的学术出版物和最近的引用中，最重要的主题是计算机科学和教育，显示了教育技术的应用如何打破了传统教育的范式。由于这些工具的普及和有效性，统计研究还提供了关于未来五年新用户预测的资料。本文总结了来自Scopus、Web of Science、SciVal和Statistical sources等来源的最重要的信息。它清晰地概述了虚拟平台和模拟在高等教育中用于学习和能力发展的实验和使用，突出了关键概念，并为未来的应用提供了指导方针。
{"title":"Framework of virtual platforms for learning and developing competencies","authors":"Nicia Guillén-Yparrea, Felipe Hernández-Rodríguez, María Soledad Ramírez-Montoya","doi":"10.1080/23311916.2023.2265632","DOIUrl":"https://doi.org/10.1080/23311916.2023.2265632","url":null,"abstract":"This work seeks to analyze the scientific evidence of the last five years and investigate the behavioral trends of virtual platforms and simulations for learning and skills development. By conducting a systematic literature review, utilizing the SciVal tool, and assessing statistical findings, we aim to establish a framework for the current status of the subject and identify the primary trends and applications of the strategies employed. Among the most relevant findings were the increase in registered users worldwide in 2021 due to the pandemic and the growth of courses available on virtual platforms such as Coursera and edEx. The most significant themes, both in indexed scholarly publications and in recent citations, were in computer science and education, showing how applications of educational technology have broken the paradigm of traditional education. Statistical studies also provide information regarding projections for new users in the next five years, owing to the popularity and effectiveness of these tools. This article summarizes the most significant information from sources such as Scopus, Web of Science, SciVal, and Statistical Sources. It presents a clear overview of the experimentation and use of virtual platforms and simulations for learning and competency development in higher education, highlighting key concepts and providing guidelines for future applications.","PeriodicalId":10464,"journal":{"name":"Cogent Engineering","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135147057","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}
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