Pub Date : 2021-12-31DOI: 10.55579/jaec.202154.344
Abbas Rezamand, M. Afrazi, Mahdi Shahidikhah
In deep excavations, because of time, budget, and computational tools limitation, two-dimensional analyses (plane strain analyses) rather than three-dimensional ones are often used for controlling factors of safety and displacements. In most excavation projects, the excavation plan includes convex and concave corners. Unlike concave corners, the use of two-dimensional analysis for convex corners is non-conservative. In the present study, by using three-dimensional numerical modeling and comparing 3D and 2D results, the effects of convex corners on the displacements induced by soil-nailed excavations are studied for two types of soil: sand (granular soil) and clay (cohesive soil). The results of the study indicate that the length of the zone affected by the convex corner (the zone along the wall and around the convex corner where the values of the displacements are greater than the corresponding two-dimensional values) is about 0.75 to 1 times the excavation's depth. The results also show that although the horizontal soil nails are executed easier and prevent interference of nails that cross, but applying an appropriate angle over the horizon (about 10 degrees) to the soil nails can reduce the wall displacements. Furthermore, it was found that applying azimuth to the soil nails in the area affected by the convex corner, significantly increased the displacements of this area. Lastly, it has been suggested that to reduce the displacements in the zone affected by the convex corner, increasing the length of the soil nails is more effective than decreasing their horizontal spacing.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.
{"title":"Study of Convex Corners' Effect on the Displacements Induced by Soil-Nailed Excavations","authors":"Abbas Rezamand, M. Afrazi, Mahdi Shahidikhah","doi":"10.55579/jaec.202154.344","DOIUrl":"https://doi.org/10.55579/jaec.202154.344","url":null,"abstract":"In deep excavations, because of time, budget, and computational tools limitation, two-dimensional analyses (plane strain analyses) rather than three-dimensional ones are often used for controlling factors of safety and displacements. In most excavation projects, the excavation plan includes convex and concave corners. Unlike concave corners, the use of two-dimensional analysis for convex corners is non-conservative. In the present study, by using three-dimensional numerical modeling and comparing 3D and 2D results, the effects of convex corners on the displacements induced by soil-nailed excavations are studied for two types of soil: sand (granular soil) and clay (cohesive soil). The results of the study indicate that the length of the zone affected by the convex corner (the zone along the wall and around the convex corner where the values of the displacements are greater than the corresponding two-dimensional values) is about 0.75 to 1 times the excavation's depth. The results also show that although the horizontal soil nails are executed easier and prevent interference of nails that cross, but applying an appropriate angle over the horizon (about 10 degrees) to the soil nails can reduce the wall displacements. Furthermore, it was found that applying azimuth to the soil nails in the area affected by the convex corner, significantly increased the displacements of this area. Lastly, it has been suggested that to reduce the displacements in the zone affected by the convex corner, increasing the length of the soil nails is more effective than decreasing their horizontal spacing.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.","PeriodicalId":250655,"journal":{"name":"J. Adv. Eng. Comput.","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122877272","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 : 2021-12-31DOI: 10.55579/jaec.202154.350
S. Patel, Jaymit Surve, Juveriya Parmar, T. Nguyen
The graphene-based absorbers are widely applicable and highly efficient. Graphene has very high electrochemical properties due to which tuning characteristics can be achieved with efficient and broadband absorption response. For this review paper, we have divided the graphene-based absorbers into three categories (Absorber sensors, Solar absorbers, and THz absorbers) based on their applications. We have presented a detailed discussion on various designs and their analysis in this paper. Absorber sensors are mainly applicable in biosensors for the detection of hemoglobin, urine biomolecules using the tuning properties of graphene, and are also applicable in medical, environmental, chemical, biological diagnostic applications. Solar absorbers are applicable in energy harvesting devices. Adding graphene layer in solar absorber design gives the highly efficient and broadband absorption response. THz absorbers are applicable in the THz applications in sensing and imaging devices. Some of the THz absorbers are improving the applications in the new field of nano-optics with 2D material. Graphene and its excellent electrical and optical properties are applied in material designs which create new structures applicable in novel applications like sensing, imaging, solar energy harvesting, etc.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.
{"title":"Review on Graphene-based Absorbers for Infrared to Ultraviolet Frequencies","authors":"S. Patel, Jaymit Surve, Juveriya Parmar, T. Nguyen","doi":"10.55579/jaec.202154.350","DOIUrl":"https://doi.org/10.55579/jaec.202154.350","url":null,"abstract":"The graphene-based absorbers are widely applicable and highly efficient. Graphene has very high electrochemical properties due to which tuning characteristics can be achieved with efficient and broadband absorption response. For this review paper, we have divided the graphene-based absorbers into three categories (Absorber sensors, Solar absorbers, and THz absorbers) based on their applications. We have presented a detailed discussion on various designs and their analysis in this paper. Absorber sensors are mainly applicable in biosensors for the detection of hemoglobin, urine biomolecules using the tuning properties of graphene, and are also applicable in medical, environmental, chemical, biological diagnostic applications. Solar absorbers are applicable in energy harvesting devices. Adding graphene layer in solar absorber design gives the highly efficient and broadband absorption response. THz absorbers are applicable in the THz applications in sensing and imaging devices. Some of the THz absorbers are improving the applications in the new field of nano-optics with 2D material. Graphene and its excellent electrical and optical properties are applied in material designs which create new structures applicable in novel applications like sensing, imaging, solar energy harvesting, etc.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.","PeriodicalId":250655,"journal":{"name":"J. Adv. Eng. Comput.","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125754425","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 : 2021-12-31DOI: 10.55579/jaec.202154.341
T. N. Nguyen, P. Fazio, M. Voznák
In this work, we investigate the performance analysis of a device-to-device (D2D) communication network under an eavesdropper E attack. Besides, we assume that E is located in the proximal region where it can overhear the information from the source S. Specifically, S transmits information to the destination D, adopting the power beacon's energy to surmount the limited energy budget. Moreover, to reduce the quality of the eavesdropping link, the cooperative jamming technique can be used, where the multi-friendly jammers are employed to generate the artificial noises to E continuously. As considering the above presentation, we derive the quality of system analysis in terms of the outage probability (OP), intercept probability (IP), and secrecy outage probability (SOP) of the proposed system model. Finally, the Monte-Carlo simulations are performed to corroborate the exactness of the mathematical analysis.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.
{"title":"On the Performance of Power Beacon-Assisted D2D Communications in the Presence of Multi-Jammers and Eavesdropper","authors":"T. N. Nguyen, P. Fazio, M. Voznák","doi":"10.55579/jaec.202154.341","DOIUrl":"https://doi.org/10.55579/jaec.202154.341","url":null,"abstract":"In this work, we investigate the performance analysis of a device-to-device (D2D) communication network under an eavesdropper E attack. Besides, we assume that E is located in the proximal region where it can overhear the information from the source S. Specifically, S transmits information to the destination D, adopting the power beacon's energy to surmount the limited energy budget. Moreover, to reduce the quality of the eavesdropping link, the cooperative jamming technique can be used, where the multi-friendly jammers are employed to generate the artificial noises to E continuously. As considering the above presentation, we derive the quality of system analysis in terms of the outage probability (OP), intercept probability (IP), and secrecy outage probability (SOP) of the proposed system model. Finally, the Monte-Carlo simulations are performed to corroborate the exactness of the mathematical analysis.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.","PeriodicalId":250655,"journal":{"name":"J. Adv. Eng. Comput.","volume":"59 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132575219","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 : 2021-12-31DOI: 10.55579/jaec.202154.342
Hau Huu Vo, Dat Vinh Phat Tran, T. Q. Thieu, T. Le, Dong Si Thien Chau, P. Brandstetter
The paper presents an application of sliding mode controller and Kalman Filter (KFSMC) in speed control of pulse-width-modulation direct torque controlled induction motor drive. The performance of the direct torque control (DTC) is degraded by the uncertainty of stator resistance. In order to increase the robustness of the controlled system to the uncertainty, a sliding mode controller (SMC) is utilized to replace the proportional-integral (PI) speed controller in the conventional DTC drive structure. Computation of SMC requires estimation of load, and Kalman Filter is integrated to reduce noise in load estimation and chattering phenomenon in speed response. Simulations are carried out at different reference speeds in a wide range of noises of stator resistance. Indices including ITAE, settling time, overshoot, and undershoot are employed to compare the performance of drive structures. Results confirmed the desired characteristics of the proposed drive structure.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.
{"title":"Sliding Mode PWM-Direct Torque Controlled Induction Motor Drive with Kalman Filtration of Estimated Load","authors":"Hau Huu Vo, Dat Vinh Phat Tran, T. Q. Thieu, T. Le, Dong Si Thien Chau, P. Brandstetter","doi":"10.55579/jaec.202154.342","DOIUrl":"https://doi.org/10.55579/jaec.202154.342","url":null,"abstract":"The paper presents an application of sliding mode controller and Kalman Filter (KFSMC) in speed control of pulse-width-modulation direct torque controlled induction motor drive. The performance of the direct torque control (DTC) is degraded by the uncertainty of stator resistance. In order to increase the robustness of the controlled system to the uncertainty, a sliding mode controller (SMC) is utilized to replace the proportional-integral (PI) speed controller in the conventional DTC drive structure. Computation of SMC requires estimation of load, and Kalman Filter is integrated to reduce noise in load estimation and chattering phenomenon in speed response. Simulations are carried out at different reference speeds in a wide range of noises of stator resistance. Indices including ITAE, settling time, overshoot, and undershoot are employed to compare the performance of drive structures. Results confirmed the desired characteristics of the proposed drive structure.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.","PeriodicalId":250655,"journal":{"name":"J. Adv. Eng. Comput.","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116926609","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 : 2021-12-31DOI: 10.55579/jaec.202154.326
Duy Suu Nguyen, Quy Hao Nghiem, Thanh Nhan Thi Do
Non-Performing Loans (NPLs) are a significant issue for all banks in Vietnam, attracting considerable attention from scholars. Our research aims to nd out the factors that affect the NPLs of Vietnamese commercial banks. The study uses Pooled Ordinary Least Square (OLS), Fixed effect, Random effect, and Generalized Least Square to examine secondary data of 28 commercial banks annually for the period 2008-2019. Consistent with previous research, the main finding shows that macroeconomic and microeconomic factors impact NPLs. Remarkably, provision for credit risk (PCR) has a significantly positive effect on the NPL ratio. Besides, foreign investor ownership (FOR) and bank size (SIZE) negatively affect the NPL ratio. Especially, for the positive correlation between foreign investor ownership and bank performance, the commercial bank should expand to enhance operational efficiency. Regarding macro factors, the results conclude that gross domestic product (GDP) growth and the unemployment rate (UEP) have a significantly negative relationship on NPLs. Therefore, the State Bank of Vietnam and the banks need to understand the leading causes as they directly relate to the banks in the context of the prevailing economic environment.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.
{"title":"Non-Performing Loans of Commercial Banks, and Their Causes: Evidence from Vietnam","authors":"Duy Suu Nguyen, Quy Hao Nghiem, Thanh Nhan Thi Do","doi":"10.55579/jaec.202154.326","DOIUrl":"https://doi.org/10.55579/jaec.202154.326","url":null,"abstract":"Non-Performing Loans (NPLs) are a significant issue for all banks in Vietnam, attracting considerable attention from scholars. Our research aims to nd out the factors that affect the NPLs of Vietnamese commercial banks. The study uses Pooled Ordinary Least Square (OLS), Fixed effect, Random effect, and Generalized Least Square to examine secondary data of 28 commercial banks annually for the period 2008-2019. Consistent with previous research, the main finding shows that macroeconomic and microeconomic factors impact NPLs. Remarkably, provision for credit risk (PCR) has a significantly positive effect on the NPL ratio. Besides, foreign investor ownership (FOR) and bank size (SIZE) negatively affect the NPL ratio. Especially, for the positive correlation between foreign investor ownership and bank performance, the commercial bank should expand to enhance operational efficiency. Regarding macro factors, the results conclude that gross domestic product (GDP) growth and the unemployment rate (UEP) have a significantly negative relationship on NPLs. Therefore, the State Bank of Vietnam and the banks need to understand the leading causes as they directly relate to the banks in the context of the prevailing economic environment.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.","PeriodicalId":250655,"journal":{"name":"J. Adv. Eng. Comput.","volume":"170 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133877931","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 : 2021-09-30DOI: 10.55579/jaec.202153.340
H. Srivastava
This survey-cum-expository review article is motivated essentially by the widespread usages of the operators of fractional calculus (that is, fractional-order integrals and fractional-order derivatives) in the modeling and analysis of a remarkably large variety of applied scientific and real-world problems in mathematical, physical, biological, engineering and statistical sciences, and in other scientific disciplines. Here, in this article, we present a brief introductory overview of the theory and applications of the fractional-calculus operators which are based upon the general Fox-Wright function and its such specialized forms as (for example) the widely- and extensively investigated and potentially useful Mittag-Leffter type functions.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.
{"title":"An Introductory Overview of Fractional-Calculus Operators Based Upon the Fox-Wright and Related Higher Transcendental Functions","authors":"H. Srivastava","doi":"10.55579/jaec.202153.340","DOIUrl":"https://doi.org/10.55579/jaec.202153.340","url":null,"abstract":"This survey-cum-expository review article is motivated essentially by the widespread usages of the operators of fractional calculus (that is, fractional-order integrals and fractional-order derivatives) in the modeling and analysis of a remarkably large variety of applied scientific and real-world problems in mathematical, physical, biological, engineering and statistical sciences, and in other scientific disciplines. Here, in this article, we present a brief introductory overview of the theory and applications of the fractional-calculus operators which are based upon the general Fox-Wright function and its such specialized forms as (for example) the widely- and extensively investigated and potentially useful Mittag-Leffter type functions.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.","PeriodicalId":250655,"journal":{"name":"J. Adv. Eng. Comput.","volume":"2008 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132679179","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 : 2021-09-30DOI: 10.55579/jaec.202153.328
A. D. Tran, Huu Hoa Tran, Viet Hung Tran
The regular increase in COVID-19 cases and deaths has resulted in a worldwide lockdown, quarantine and some restrictions. Due to the lack of a COVID-19 vaccine, it is critical for developing and least developed countries like Vietnam to investigate the efficacy of non-pharmaceutical treatments like social distance or national lockdown in preventing COVID-19 transmission. To address this need, the goal of this study was to develop a clear and reliable model for assessing the impact of social distancing on the spread of coronavirus in Vietnam. For the case study, the Logistic Growth Curve (LGC) model, also known as the Sigmoid model, was chosen to fit COVID-19 infection data from January 23, 2020 to April 30, 2020 in Vietnam. To determine the optimal set of LGC model parameters, we used the gradient descent technique. We were pleasantly surprised to discover that the LGC model accurately predicted COVID-19 community transmission cases over this time period, with very high correlation coefficient value r = 0.993. The results of this study imply that using social distancing technique to flatten the curve of coronavirus disease infections will help minimize the surge in active COVID-19 cases and the spread of COVID-19 infections. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.
{"title":"Evaluating the Impact of Social Distancing on COVID-19 Spread in Vietnam by using Logistic Growth Curve Model","authors":"A. D. Tran, Huu Hoa Tran, Viet Hung Tran","doi":"10.55579/jaec.202153.328","DOIUrl":"https://doi.org/10.55579/jaec.202153.328","url":null,"abstract":"The regular increase in COVID-19 cases and deaths has resulted in a worldwide lockdown, quarantine and some restrictions. Due to the lack of a COVID-19 vaccine, it is critical for developing and least developed countries like Vietnam to investigate the efficacy of non-pharmaceutical treatments like social distance or national lockdown in preventing COVID-19 transmission. To address this need, the goal of this study was to develop a clear and reliable model for assessing the impact of social distancing on the spread of coronavirus in Vietnam. For the case study, the Logistic Growth Curve (LGC) model, also known as the Sigmoid model, was chosen to fit COVID-19 infection data from January 23, 2020 to April 30, 2020 in Vietnam. To determine the optimal set of LGC model parameters, we used the gradient descent technique. We were pleasantly surprised to discover that the LGC model accurately predicted COVID-19 community transmission cases over this time period, with very high correlation coefficient value r = 0.993. The results of this study imply that using social distancing technique to flatten the curve of coronavirus disease infections will help minimize the surge in active COVID-19 cases and the spread of COVID-19 infections. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited. ","PeriodicalId":250655,"journal":{"name":"J. Adv. Eng. Comput.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126226444","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 : 2021-09-30DOI: 10.55579/jaec.202153.336
Pankti Shah, Yesha Patel, A. Desai, J. Kulkarni, T. Upadhyaya, M. Palandoken
A transparent dual octagonal split ring-shaped resonator connected by a horizontal strip is proposed for tri-band applications. Stub-loaded microstrip line fed structural design of radiator consists of two slotted octagonal-shaped rings connected via a strip on the top with the partial ground at the back. The low profile (40×25 mm2) radiator achieves impedance bandwidth of (46.08%) 1.62-2.59,(7.78%) 3.95-4.27, and (12.60%) 5.13-5.82, respectively. A bi-directional (dipole shaped) radiation pattern with maximum gain and minimum efficiency of 2.5 dBi and 52%, respectively is achieved. Transparency above 80%, low profile structure, and tri-band operation make the antenna a good contender for WLAN and Sub-6 GHz 5G applications. Good correlation is observed for the modeled and experimental parameters. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.
{"title":"Low-Profile Dual Hollow Octagonal Ring Shaped Optically Transparent Tri-band Antenna for WLAN and Sub-6 GHz 5G Applications","authors":"Pankti Shah, Yesha Patel, A. Desai, J. Kulkarni, T. Upadhyaya, M. Palandoken","doi":"10.55579/jaec.202153.336","DOIUrl":"https://doi.org/10.55579/jaec.202153.336","url":null,"abstract":"A transparent dual octagonal split ring-shaped resonator connected by a horizontal strip is proposed for tri-band applications. Stub-loaded microstrip line fed structural design of radiator consists of two slotted octagonal-shaped rings connected via a strip on the top with the partial ground at the back. The low profile (40×25 mm2) radiator achieves impedance bandwidth of (46.08%) 1.62-2.59,(7.78%) 3.95-4.27, and (12.60%) 5.13-5.82, respectively. A bi-directional (dipole shaped) radiation pattern with maximum gain and minimum efficiency of 2.5 dBi and 52%, respectively is achieved. Transparency above 80%, low profile structure, and tri-band operation make the antenna a good contender for WLAN and Sub-6 GHz 5G applications. Good correlation is observed for the modeled and experimental parameters. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.","PeriodicalId":250655,"journal":{"name":"J. Adv. Eng. Comput.","volume":"150 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122441166","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 : 2021-09-30DOI: 10.55579/jaec.202153.334
Dung Quang Nguyen, Q. Nguyen, T. V. Nguyen, Tai Huu Le, Hau Huu Vo, P. Brandstetter
The paper deals with the utilization of Kalman filter and fuzzy logic control in induction motor drive with direct torque control (DTC). In order to lower ripple of stator current vector in DTC drive, pulse width modulation technique with high switching frequency is applied. However, the performance of the DTC also depends on the accuracy of both stator resistance and stator current vector. In the paper, the stator resistance and stator current components are assumed to be distorted by Gaussian noises. In order to reduce the effect of noises especially at low speed and very low speed regions, a simple Kalman filter is applied for filtering current components, and fuzzy logic theory is used to increase the flexibility of proportional-integral (PI) compensator in the speed controller of the drive structure. Simulations are implemented in conditions of high-level noises of stator current and stator resistance, and a wide range of load torque. An ITAE-based criterion is utilized to evaluate the performance of drive structures. Results confirmed the expected dynamic properties of the proposed drive structure. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.
{"title":"Simplified Control Structure of Fuzzy Logic and Kalman Filter for Induction Motor Drive","authors":"Dung Quang Nguyen, Q. Nguyen, T. V. Nguyen, Tai Huu Le, Hau Huu Vo, P. Brandstetter","doi":"10.55579/jaec.202153.334","DOIUrl":"https://doi.org/10.55579/jaec.202153.334","url":null,"abstract":"The paper deals with the utilization of Kalman filter and fuzzy logic control in induction motor drive with direct torque control (DTC). In order to lower ripple of stator current vector in DTC drive, pulse width modulation technique with high switching frequency is applied. However, the performance of the DTC also depends on the accuracy of both stator resistance and stator current vector. In the paper, the stator resistance and stator current components are assumed to be distorted by Gaussian noises. In order to reduce the effect of noises especially at low speed and very low speed regions, a simple Kalman filter is applied for filtering current components, and fuzzy logic theory is used to increase the flexibility of proportional-integral (PI) compensator in the speed controller of the drive structure. Simulations are implemented in conditions of high-level noises of stator current and stator resistance, and a wide range of load torque. An ITAE-based criterion is utilized to evaluate the performance of drive structures. Results confirmed the expected dynamic properties of the proposed drive structure. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.","PeriodicalId":250655,"journal":{"name":"J. Adv. Eng. Comput.","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122410087","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 : 2021-09-30DOI: 10.55579/jaec.202153.305
Nguyen Hai Son Dang, Doan Minh Thong Nguyen, Thi Phuong Loan Nguyen, Doan Quoc Anh Nguyen, Hsiao-Yi Lee
One of the most important factors used to evaluate lighting performances ofWLEDs is the angular color uniformity (ACU). The triple-layer remote phosphor structure is considered as a proposed mechanism for elevating the ACU of a WLED. The analysis on the triple-layer structure's efficiency is specifically demonstrated in this article. Additionally, there are detailed comparisons between the triple-layer (TL) and the dual-layer (DL) geometries to reinforce the idea of using TL packaging for WLED optical enhancements. The WLEDs with average correlated color temperatures (ACCTs) of 6600 K and 7700 K are utilized for experiments. According to the outcomes, the attained color rendering index from DL design is higher than the one from TL package. However, the TL shows better color quality scale (CQS) than the DL, regardless of ACCTs. Besides, not only does the TL yield better CQS but also heighten the lumen efficiency. On top of that, the ACU of TL WLED model is much higher than that of the DL as a result of deviated correlated color temperature reduction at all ACCTs. This result is more obvious at the high ACCT of 7700 K, in other words, the ACU of a high-ACCT WLED shows more visible enhancement with TL structure. From these results, the triple-layer remote phosphor structure stands out as the promising advancement in the production of high-quality WLEDs.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.
{"title":"Enhance WLEDs Performance with Additional Phosphor Materials in Multi-Layer Remote Structure","authors":"Nguyen Hai Son Dang, Doan Minh Thong Nguyen, Thi Phuong Loan Nguyen, Doan Quoc Anh Nguyen, Hsiao-Yi Lee","doi":"10.55579/jaec.202153.305","DOIUrl":"https://doi.org/10.55579/jaec.202153.305","url":null,"abstract":"One of the most important factors used to evaluate lighting performances ofWLEDs is the angular color uniformity (ACU). The triple-layer remote phosphor structure is considered as a proposed mechanism for elevating the ACU of a WLED. The analysis on the triple-layer structure's efficiency is specifically demonstrated in this article. Additionally, there are detailed comparisons between the triple-layer (TL) and the dual-layer (DL) geometries to reinforce the idea of using TL packaging for WLED optical enhancements. The WLEDs with average correlated color temperatures (ACCTs) of 6600 K and 7700 K are utilized for experiments. According to the outcomes, the attained color rendering index from DL design is higher than the one from TL package. However, the TL shows better color quality scale (CQS) than the DL, regardless of ACCTs. Besides, not only does the TL yield better CQS but also heighten the lumen efficiency. On top of that, the ACU of TL WLED model is much higher than that of the DL as a result of deviated correlated color temperature reduction at all ACCTs. This result is more obvious at the high ACCT of 7700 K, in other words, the ACU of a high-ACCT WLED shows more visible enhancement with TL structure. From these results, the triple-layer remote phosphor structure stands out as the promising advancement in the production of high-quality WLEDs.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited.","PeriodicalId":250655,"journal":{"name":"J. Adv. Eng. Comput.","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125428046","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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