Pub Date : 2022-06-30DOI: 10.55579/jaec.202262.332
A. Le, S. D. Ho, Doan Quoc Anh Nguyen, Hsiao-Yi Lee
The remote phosphor structure is proven to be better than other structures of conformal or in-cup phosphor in terms of luminous efciency. Nevertheless, its color rendering ability is unstable and difficult to manage at high correlated color temperature (CCT). Hence, improving the color management at high CCT for remote structures is essential. This study will present the triple-layer structures using the yellow phosphor YAG:Ce3+, the red YVO4:Eu3+ and green YF3:Mn2+ phosphors to achieve that control over the color and luminous properties of WLED packages. The results of the triple-layer structure are compared with those of the conventional remote phosphor structure (single-layer). The experiments performed on these two structures with the CCT range of 5600–8500 K. The findings in the study show that the triple-layer is more benefcial to the color rendering metric, color quality scale, and also the lumen output, especially at high color temperatures such as 8500 K, compared to the conventional one. Moreover, the higher color uniformity is accomplished with the triple-layer structure as the color deviation in this structure is much smaller than in the single-layer. Thus, the triple-layer structure can be applied as a replacement to the single-layer to attain better control of the color quality and luminous flux for high-CCT 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":"Triple-layer Design of YVO4: Eu3+, YF3: Mn2+, and YAG: Ce3+: the Potential for Advancement of Remote Phosphor Structure to Get Better Chromaticity and Luminescence at High Color Temperatures","authors":"A. Le, S. D. Ho, Doan Quoc Anh Nguyen, Hsiao-Yi Lee","doi":"10.55579/jaec.202262.332","DOIUrl":"https://doi.org/10.55579/jaec.202262.332","url":null,"abstract":"The remote phosphor structure is proven to be better than other structures of conformal or in-cup phosphor in terms of luminous efciency. Nevertheless, its color rendering ability is unstable and difficult to manage at high correlated color temperature (CCT). Hence, improving the color management at high CCT for remote structures is essential. This study will present the triple-layer structures using the yellow phosphor YAG:Ce3+, the red YVO4:Eu3+ and green YF3:Mn2+ phosphors to achieve that control over the color and luminous properties of WLED packages. The results of the triple-layer structure are compared with those of the conventional remote phosphor structure (single-layer). The experiments performed on these two structures with the CCT range of 5600–8500 K. The findings in the study show that the triple-layer is more benefcial to the color rendering metric, color quality scale, and also the lumen output, especially at high color temperatures such as 8500 K, compared to the conventional one. Moreover, the higher color uniformity is accomplished with the triple-layer structure as the color deviation in this structure is much smaller than in the single-layer. Thus, the triple-layer structure can be applied as a replacement to the single-layer to attain better control of the color quality and luminous flux for high-CCT 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":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121639325","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 : 2022-06-30DOI: 10.55579/jaec.202262.377
K. Takizawa, Y. Bazilevs, T. Tezduyar
A good mesh moving method is an important part of flow computations with moving-mesh methods like the space–time (ST) and Arbitrary Lagrangian–Eulerian (ALE) methods. With a good mesh moving method, we can decrease the remeshing frequency even when the fluid–solid and fluid–fluid interfaces undergo large displacements, decrease the element distortion in parts of the flow domain where we care about the solution accuracy more, and maintain the quality of the boundary layer meshes near the fluid–solid interfaces as the mesh moves to follow those interfaces. Since 1990, quite a few good mesh moving methods have been developed for use with the ST computational methods, from the mesh Jacobian-based stiffening to a mesh moving method based on fiber-reinforced hyperelasticity to a linear-elasticity mesh moving method with no cycle-to-cycle accumulated distortion. These methods have been used in computation of many complex flow problems in the categories of fluid–particle interaction, fluid–structure interaction, and more generally, moving boundaries and interfaces. The computations were with both the ST and ALE methods. We provide an overview of these methods and present examples of the computations performed.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":"Mesh Moving Methods in Flow Computations with the Space-Time and Arbitrary Lagrangian-Eulerian Methods","authors":"K. Takizawa, Y. Bazilevs, T. Tezduyar","doi":"10.55579/jaec.202262.377","DOIUrl":"https://doi.org/10.55579/jaec.202262.377","url":null,"abstract":"A good mesh moving method is an important part of flow computations with moving-mesh methods like the space–time (ST) and Arbitrary Lagrangian–Eulerian (ALE) methods. With a good mesh moving method, we can decrease the remeshing frequency even when the fluid–solid and fluid–fluid interfaces undergo large displacements, decrease the element distortion in parts of the flow domain where we care about the solution accuracy more, and maintain the quality of the boundary layer meshes near the fluid–solid interfaces as the mesh moves to follow those interfaces. Since 1990, quite a few good mesh moving methods have been developed for use with the ST computational methods, from the mesh Jacobian-based stiffening to a mesh moving method based on fiber-reinforced hyperelasticity to a linear-elasticity mesh moving method with no cycle-to-cycle accumulated distortion. These methods have been used in computation of many complex flow problems in the categories of fluid–particle interaction, fluid–structure interaction, and more generally, moving boundaries and interfaces. The computations were with both the ST and ALE methods. We provide an overview of these methods and present examples of the computations performed.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":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127109470","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 : 2022-06-30DOI: 10.55579/jaec.202262.355
M. Sazzad
The aim of this paper is to explore the evolution of different micro-scale quantities during the cyclic loading using the discrete element method (DEM) for a granulate system such as sand. The numerical samples comprising of 9826 spheres were generated and consolidated isotropically using the periodic boundaries. These numerical samples were subjected to the cyclic loading for different maximum applied strains. The simulated stress-strain behavior was validated with the experiment and found an excellent agreement between them during loading and unloading. The evolutions of different micro-scale quantities were investigated in detail considering the variation of the maximum applied strain and the density of sample. It is noted that the evolution of the coordination number and the slip coordination number is a function of the maximum applied strain and the density of sample during the cyclic loading. The change of the slip coordination number is larger at the end of unloading than that at end of loading during the cyclic loading regardless of the values of the maximum applied strain and the density of sample. The ratio of strong contacts to all the contacts increases abruptly when the load is reversed, which is opposite to what is observed for the coordination number and the slip coordination number. The deviatoric fabric computed by the fabric tensor considering the strong contacts mimics the deviatoric stress irrespective of the values of the maximum applied strain and the density of sample during the cyclic loading. Moreover, a linear correlation between the macro and micro quantities exists regardless of the variation of the maximum applied strains or the variation of the density of the sample during the cyclic loading. The slopes of the lines of these correlations are almost same.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":"Behavior of Sheared Granular Materials at Micro-Scale during the Cyclic Loading","authors":"M. Sazzad","doi":"10.55579/jaec.202262.355","DOIUrl":"https://doi.org/10.55579/jaec.202262.355","url":null,"abstract":"The aim of this paper is to explore the evolution of different micro-scale quantities during the cyclic loading using the discrete element method (DEM) for a granulate system such as sand. The numerical samples comprising of 9826 spheres were generated and consolidated isotropically using the periodic boundaries. These numerical samples were subjected to the cyclic loading for different maximum applied strains. The simulated stress-strain behavior was validated with the experiment and found an excellent agreement between them during loading and unloading. The evolutions of different micro-scale quantities were investigated in detail considering the variation of the maximum applied strain and the density of sample. It is noted that the evolution of the coordination number and the slip coordination number is a function of the maximum applied strain and the density of sample during the cyclic loading. The change of the slip coordination number is larger at the end of unloading than that at end of loading during the cyclic loading regardless of the values of the maximum applied strain and the density of sample. The ratio of strong contacts to all the contacts increases abruptly when the load is reversed, which is opposite to what is observed for the coordination number and the slip coordination number. The deviatoric fabric computed by the fabric tensor considering the strong contacts mimics the deviatoric stress irrespective of the values of the maximum applied strain and the density of sample during the cyclic loading. Moreover, a linear correlation between the macro and micro quantities exists regardless of the variation of the maximum applied strains or the variation of the density of the sample during the cyclic loading. The slopes of the lines of these correlations are almost same.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":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116720687","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 : 2022-06-30DOI: 10.55579/jaec.202262.353
Trang Cong Nguyen, Chiem Trong Hien, D. Phan
In this paper, a novel single phase second order sliding mode controller (SPSOSMC) is proposed for the mismatched uncertain systems with extended disturbances and unknown time-varying delays. The main achievements of this study consist of three tasks: 1) a reaching phase in conventional sliding mode control (CSMC) technique is removed to ensure the global stability of the system; 2) an influence of the undesired high-frequency oscillation phenomenon in control input is vanished; 3) an exogenous perturbation is generally extended to the k-order disturbance of state variable. Firstly, a single phase switching manifold function is defined to eliminate the reaching phase in CSMC. Secondly, an unmeasurable state variable is estimated by using the proposed reduced-order sliding mode observer (ROSMO) tool. Next, a SPSOSMC is built based on the help of ROSMO tool and output information only. Then, a sufficient condition is established by employing the linear matrix inequality (LMI) technique and Lyapunov function theory such that the resulting sliding mode dynamics is asymptotically stable. Finally, a numerical example is simulated via the well-known MATLAB software to validate the effectiveness of the proposed technique.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":"Single Phase Second Order Sliding Mode Controller for Mismatched Uncertain Systems with Extended Disturbances and Unknown Time-Varying Delays","authors":"Trang Cong Nguyen, Chiem Trong Hien, D. Phan","doi":"10.55579/jaec.202262.353","DOIUrl":"https://doi.org/10.55579/jaec.202262.353","url":null,"abstract":"In this paper, a novel single phase second order sliding mode controller (SPSOSMC) is proposed for the mismatched uncertain systems with extended disturbances and unknown time-varying delays. The main achievements of this study consist of three tasks: 1) a reaching phase in conventional sliding mode control (CSMC) technique is removed to ensure the global stability of the system; 2) an influence of the undesired high-frequency oscillation phenomenon in control input is vanished; 3) an exogenous perturbation is generally extended to the k-order disturbance of state variable. Firstly, a single phase switching manifold function is defined to eliminate the reaching phase in CSMC. Secondly, an unmeasurable state variable is estimated by using the proposed reduced-order sliding mode observer (ROSMO) tool. Next, a SPSOSMC is built based on the help of ROSMO tool and output information only. Then, a sufficient condition is established by employing the linear matrix inequality (LMI) technique and Lyapunov function theory such that the resulting sliding mode dynamics is asymptotically stable. Finally, a numerical example is simulated via the well-known MATLAB software to validate the effectiveness of the proposed technique.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":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127441788","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 : 2022-06-30DOI: 10.55579/jaec.202262.354
T. Q. Thieu, Anh Phuc Hoang Le, Minh Tam Pham, Phan Nguyen Ky Phuc, Viet Hung Tran
The reverse supply chain (RSC) recently attracted many Vietnamese authorities, enterprises and academia owing to the rise of concern on the environment and regulations of waste process. Along with rapid development, Vietnamese manufacturing network has become tightly strained when the end-of-life (EOL) items are not taken back by their manufacturers but end up being processed disorderly in different local businesses. A distressing example is the waste of imported solar panels in Vietnam. Since the number of solar panels has grown steadily in Vietnam recently, we speculate that the network flows of EOL solar panel of Vietnam will be very large and complex in a few years. In order to help Vietnamese government establish efficiently RSC, our paper will apply the mixed-integer linear programming (MILP) and demonstrate an optimized solution for the RSC of EOL solar panel in Ho Chi Minh City. Indeed, via our collected data from current financial market of Ho Chi Minh city, our MILP shows that the optimal cost-reduction is 11219 USD, even with limited constraints of only two landfills and very few collection facilities in Ho Chi Minh city at the moment. This result of our proposed RSC demonstrates that a significant profit is definitely possible when the number of collection facilities in Ho Chi Minh city increase in the future. Also, our MILP approach is flexible for decision-makers to achieve a satisfactory solution.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":"A Reverse Supply Chain Model to Reduce Waste of Solar Panel in Ho Chi Minh City, Vietnam","authors":"T. Q. Thieu, Anh Phuc Hoang Le, Minh Tam Pham, Phan Nguyen Ky Phuc, Viet Hung Tran","doi":"10.55579/jaec.202262.354","DOIUrl":"https://doi.org/10.55579/jaec.202262.354","url":null,"abstract":"The reverse supply chain (RSC) recently attracted many Vietnamese authorities, enterprises and academia owing to the rise of concern on the environment and regulations of waste process. Along with rapid development, Vietnamese manufacturing network has become tightly strained when the end-of-life (EOL) items are not taken back by their manufacturers but end up being processed disorderly in different local businesses. A distressing example is the waste of imported solar panels in Vietnam. Since the number of solar panels has grown steadily in Vietnam recently, we speculate that the network flows of EOL solar panel of Vietnam will be very large and complex in a few years. In order to help Vietnamese government establish efficiently RSC, our paper will apply the mixed-integer linear programming (MILP) and demonstrate an optimized solution for the RSC of EOL solar panel in Ho Chi Minh City. Indeed, via our collected data from current financial market of Ho Chi Minh city, our MILP shows that the optimal cost-reduction is 11219 USD, even with limited constraints of only two landfills and very few collection facilities in Ho Chi Minh city at the moment. This result of our proposed RSC demonstrates that a significant profit is definitely possible when the number of collection facilities in Ho Chi Minh city increase in the future. Also, our MILP approach is flexible for decision-makers to achieve a satisfactory solution.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":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126139823","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 : 2022-03-31DOI: 10.55579/jaec.202261.348
M. Trần, C. Tran, B. H. Dinh, Tai Thanh Phan, Trang Huynh-Cong Nguyen, Huy Truong Nguyen, Giang Thi-Tuyet Lai, Huy Xuan Phan
An enhanced technique combining hysteresis current (HC) and sine pulse width modulation (SPWM) for generating the switching pulse to the inverter is proposed for speed control based on a rotor field-oriented control (RFOC) strategy in the induction motor drive. HC method is a simple and robust control method, it has a fast response in speed control, but the rotor speed and the stator current have high ripple. SPWM method, a popular method in triangular carrier wave modulation methods, has high precision in controlling the speed and torque of the motor; however, the high overshoot of the speed response in the transient phase is the weakness of this method. In this paper, a combined method of the above two methods, called hysteresis current-sine pulse width modulation (HCSPWM), is proposed for motor speed control. The simulations are implemented at various speed ranges in MatLab/Simulink environment. The simulation results have proved that the proposed method has a lower overshoot than the SPWM method in the transient-state and a lower ripple than the HC method in the steady-state in the same operating condition.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":"Speed Control Applying Hysteresis Current Combining Sine Pulse Width Modulation for Induction Motor Drive","authors":"M. Trần, C. Tran, B. H. Dinh, Tai Thanh Phan, Trang Huynh-Cong Nguyen, Huy Truong Nguyen, Giang Thi-Tuyet Lai, Huy Xuan Phan","doi":"10.55579/jaec.202261.348","DOIUrl":"https://doi.org/10.55579/jaec.202261.348","url":null,"abstract":"An enhanced technique combining hysteresis current (HC) and sine pulse width modulation (SPWM) for generating the switching pulse to the inverter is proposed for speed control based on a rotor field-oriented control (RFOC) strategy in the induction motor drive. HC method is a simple and robust control method, it has a fast response in speed control, but the rotor speed and the stator current have high ripple. SPWM method, a popular method in triangular carrier wave modulation methods, has high precision in controlling the speed and torque of the motor; however, the high overshoot of the speed response in the transient phase is the weakness of this method. In this paper, a combined method of the above two methods, called hysteresis current-sine pulse width modulation (HCSPWM), is proposed for motor speed control. The simulations are implemented at various speed ranges in MatLab/Simulink environment. The simulation results have proved that the proposed method has a lower overshoot than the SPWM method in the transient-state and a lower ripple than the HC method in the steady-state in the same operating condition.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":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121951158","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 : 2022-03-31DOI: 10.55579/jaec.202261.351
Tai Huu Le, Phu Thai Ngo, Van Ngu Tran, Viet Hung Tran
Internet of things (IoT) is increasingly useful in connecting network of devices on the internet. A popular need of IoT in the industry is to measure the level of the liquid in a faraway tank of interest. The traditional measurement method uses float, pressure or ultrasonic sensor and provides reliable results. Nonetheless, the disadvantages of traditional methods are that their range of measurement is rather short and their maintenance on the field is also difficult. To solve these problems, we propose a novel method that combines the image processing algorithm with Node-Red IoT systems. The original idea of this paper is to use the image of the ruler on the tank for measuring the physical height of liquid level in standard units. Our experimental results on real-time collected images via IoT live-streaming show that our proposed method is very fast and robust with different size and shape of different rulers. Our method is also accurate enough to facilitate the application of liquid level measurement in practice.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":"Liquid Level Detection via Node-Red and Automatic Image Processing System","authors":"Tai Huu Le, Phu Thai Ngo, Van Ngu Tran, Viet Hung Tran","doi":"10.55579/jaec.202261.351","DOIUrl":"https://doi.org/10.55579/jaec.202261.351","url":null,"abstract":"Internet of things (IoT) is increasingly useful in connecting network of devices on the internet. A popular need of IoT in the industry is to measure the level of the liquid in a faraway tank of interest. The traditional measurement method uses float, pressure or ultrasonic sensor and provides reliable results. Nonetheless, the disadvantages of traditional methods are that their range of measurement is rather short and their maintenance on the field is also difficult. To solve these problems, we propose a novel method that combines the image processing algorithm with Node-Red IoT systems. The original idea of this paper is to use the image of the ruler on the tank for measuring the physical height of liquid level in standard units. Our experimental results on real-time collected images via IoT live-streaming show that our proposed method is very fast and robust with different size and shape of different rulers. Our method is also accurate enough to facilitate the application of liquid level measurement in practice.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":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115131745","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 : 2022-03-31DOI: 10.55579/jaec.202261.357
Yongzheng Zhang, H. Ren, T. Rabczuk
The nonlocal operator method (NOM) is based on nonlocal theory and employs nonlocal operators of integral form to replace the local partial differential operators. NOM naturally bridges models of different length scales and enables also the natural solution of problems with continuous to discontinuous solutions as they occur in the case of material failure. It also provides a natural framework for complex multifield problems. It is based on a variational principle or weighted residual method and only requires the definition of associated energy potential. As the NOM does not require any shape functions as ’traditional methods’ such as FEM, IGA or meshfree methods, its implementation is significantly simplified. It has been successfully applied to the solution of several partial differential equations (PDEs). This paper aims to provide a comprehensive description of the NOM together with a review of its major applications for the solution of PDEs for challenging engineering problems. Finally, we give some potential future research direction in the area of methods based on nonlocal operators.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":"Nonlocal Operator Method for Solving Partial Differential Equations: State-of-the-Art Review and Future Perspectives","authors":"Yongzheng Zhang, H. Ren, T. Rabczuk","doi":"10.55579/jaec.202261.357","DOIUrl":"https://doi.org/10.55579/jaec.202261.357","url":null,"abstract":"The nonlocal operator method (NOM) is based on nonlocal theory and employs nonlocal operators of integral form to replace the local partial differential operators. NOM naturally bridges models of different length scales and enables also the natural solution of problems with continuous to discontinuous solutions as they occur in the case of material failure. It also provides a natural framework for complex multifield problems. It is based on a variational principle or weighted residual method and only requires the definition of associated energy potential. As the NOM does not require any shape functions as ’traditional methods’ such as FEM, IGA or meshfree methods, its implementation is significantly simplified. It has been successfully applied to the solution of several partial differential equations (PDEs). This paper aims to provide a comprehensive description of the NOM together with a review of its major applications for the solution of PDEs for challenging engineering problems. Finally, we give some potential future research direction in the area of methods based on nonlocal operators.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":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130587052","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 : 2022-03-31DOI: 10.55579/jaec.202261.339
Doan Minh Thong Nguyen, Nguyen Hai Son Dang, S. D. Ho, Doan Quoc Anh Nguyen, Hsiao-Yi Lee
Although distant phosphor structure is not the best choice for color fidelity of white-light-emitting diode (W-LED) sources, it benefits the luminous flux of LED more than conformal or in-cup phosphor models. After recognizing the potential of remote phosphor structures, numerous studies have been done to overcome their drawbacks of light chromaticity. In this study, a phosphor package with two phosphor films is suggested for the W-LED. The two-layer remote phosphor structure is recognized to offer a great probability of heightened chromatic rendering parameters, including the color rending index CRI and the color quality scale CQS. The color temperature of the W-LEDs employed in this investigation is 8500 K. Placing a layer of green Y3Al5O12:Ce3+ or red CaTiO3:Pr3+ phosphor on top of the yellow phosphor YAG:Ce3+ layer will create the desired two-layered phosphor structure's form. The added phosphor CaTiO3:Pr3+ concentration will then be adjusted to achieve the best color quality. The existence of CaTiO3:Pr3+ increased CRI and CQS, implying that it has a significant impact on these two features. The concentration of CaTiO3:Pr3+ parallel with the CRI and CQS as the red spectral component is promoted within the W-LED. In the meantime, the green phosphor Y3Al5O12:Ce3+ advances the luminous flux. However, if the red CaTiO3:Pr3+ and green Y3Al5O12:Ce3+ phosphor concentrations are above the respective levels, it will diminish the luminous flux and color quality. According to Mie-scattering theory and Lambert- Beer's law to describe the outcome of this research. The conclusions of this study are crucial guidelines for producing better white light quality in W-LEDs.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":"The Use of Y3Al5O12: Ce3+ and CaTiO3: Pr3+ in a Dual-layer Remote Phosphor Configuration Improves the Optical Efficiencies of a Phosphor-in-Glass White Light-Emitting Diode","authors":"Doan Minh Thong Nguyen, Nguyen Hai Son Dang, S. D. Ho, Doan Quoc Anh Nguyen, Hsiao-Yi Lee","doi":"10.55579/jaec.202261.339","DOIUrl":"https://doi.org/10.55579/jaec.202261.339","url":null,"abstract":"Although distant phosphor structure is not the best choice for color fidelity of white-light-emitting diode (W-LED) sources, it benefits the luminous flux of LED more than conformal or in-cup phosphor models. After recognizing the potential of remote phosphor structures, numerous studies have been done to overcome their drawbacks of light chromaticity. In this study, a phosphor package with two phosphor films is suggested for the W-LED. The two-layer remote phosphor structure is recognized to offer a great probability of heightened chromatic rendering parameters, including the color rending index CRI and the color quality scale CQS. The color temperature of the W-LEDs employed in this investigation is 8500 K. Placing a layer of green Y3Al5O12:Ce3+ or red CaTiO3:Pr3+ phosphor on top of the yellow phosphor YAG:Ce3+ layer will create the desired two-layered phosphor structure's form. The added phosphor CaTiO3:Pr3+ concentration will then be adjusted to achieve the best color quality. The existence of CaTiO3:Pr3+ increased CRI and CQS, implying that it has a significant impact on these two features. The concentration of CaTiO3:Pr3+ parallel with the CRI and CQS as the red spectral component is promoted within the W-LED. In the meantime, the green phosphor Y3Al5O12:Ce3+ advances the luminous flux. However, if the red CaTiO3:Pr3+ and green Y3Al5O12:Ce3+ phosphor concentrations are above the respective levels, it will diminish the luminous flux and color quality. According to Mie-scattering theory and Lambert- Beer's law to describe the outcome of this research. The conclusions of this study are crucial guidelines for producing better white light quality in W-LEDs.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":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124425973","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 : 2022-03-31DOI: 10.55579/jaec.202261.362
Shobhit K. Patel, C. Bui, T. Nguyen, Juveriya Parmar, Q. M. Ngo
In this paper, a frequency reconfigurable liquid metamaterial microstrip-based radiating structure is proposed and it is an attempt toward achieving reconfiguration in liquid metamaterial-based microstrip radiating structures. Reconfigurable antenna design is superstrated with five liquid metamaterial layers based on a distilled water split-ring resonator. Superstrate layers give enhancement from 6.5 dB to 13.1 dB in gain of the proposed antenna. A patch is reconfigured through PIN diodes as RF switches. Switching ‘on’ and ‘off’ states of PIN diodes are used for reconfiguration of frequency and radiation patterns. Analysis in terms of reflection coefficient, gain (dBi), radiation pattern, bandwidth (BW), and half-power beamwidth (HPBW) is obtained in switch-off and switch-on state. The proposed design provides enhanced gain, reflection coefficient, and multiband characteristics in the 8-12 GHz range suitable for X-band satellite and radar applications. 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":"Numerical Investigation of Frequency Reconfigurable Antenna with Liquid Metamaterials for X-band","authors":"Shobhit K. Patel, C. Bui, T. Nguyen, Juveriya Parmar, Q. M. Ngo","doi":"10.55579/jaec.202261.362","DOIUrl":"https://doi.org/10.55579/jaec.202261.362","url":null,"abstract":"In this paper, a frequency reconfigurable liquid metamaterial microstrip-based radiating structure is proposed and it is an attempt toward achieving reconfiguration in liquid metamaterial-based microstrip radiating structures. Reconfigurable antenna design is superstrated with five liquid metamaterial layers based on a distilled water split-ring resonator. Superstrate layers give enhancement from 6.5 dB to 13.1 dB in gain of the proposed antenna. A patch is reconfigured through PIN diodes as RF switches. Switching ‘on’ and ‘off’ states of PIN diodes are used for reconfiguration of frequency and radiation patterns. Analysis in terms of reflection coefficient, gain (dBi), radiation pattern, bandwidth (BW), and half-power beamwidth (HPBW) is obtained in switch-off and switch-on state. The proposed design provides enhanced gain, reflection coefficient, and multiband characteristics in the 8-12 GHz range suitable for X-band satellite and radar applications. 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":"121 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116710700","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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