The rapid evolution of wireless communication technologies has underscored the critical role of antennas in ensuring seamless connectivity.Antenna defects,ranging from manufacturing imperfections to environmental wear...The rapid evolution of wireless communication technologies has underscored the critical role of antennas in ensuring seamless connectivity.Antenna defects,ranging from manufacturing imperfections to environmental wear,pose significant challenges to the reliability and performance of communication systems.This review paper navigates the landscape of antenna defect detection,emphasizing the need for a nuanced understanding of various defect types and the associated challenges in visual detection.This review paper serves as a valuable resource for researchers,engineers,and practitioners engaged in the design and maintenance of communication systems.The insights presented here pave the way for enhanced reliability in antenna systems through targeted defect detection measures.In this study,a comprehensive literature analysis on computer vision algorithms that are employed in end-of-line visual inspection of antenna parts is presented.The PRISMA principles will be followed throughout the review,and its goals are to provide a summary of recent research,identify relevant computer vision techniques,and evaluate how effective these techniques are in discovering defects during inspections.It contains articles from scholarly journals as well as papers presented at conferences up until June 2023.This research utilized search phrases that were relevant,and papers were chosen based on whether or not they met certain inclusion and exclusion criteria.In this study,several different computer vision approaches,such as feature extraction and defect classification,are broken down and analyzed.Additionally,their applicability and performance are discussed.The review highlights the significance of utilizing a wide variety of datasets and measurement criteria.The findings of this study add to the existing body of knowledge and point researchers in the direction of promising new areas of investigation,such as real-time inspection systems and multispectral imaging.This review,on its whole,offers a complete study of computer vision approaches for quality control in antenna parts.It does so by providing helpful insights and drawing attention to areas that require additional exploration.展开更多
Apart from socio-economic disparities,indigenous people of the Himalayan range in Asia face an increasing trend of suicides.The tragic suicidal events usually go unaddressed,and no strategies are presently in place to...Apart from socio-economic disparities,indigenous people of the Himalayan range in Asia face an increasing trend of suicides.The tragic suicidal events usually go unaddressed,and no strategies are presently in place to mitigate suicides in the future.This study aims to explain the prevailing causes of suicidal ideation to come up with some policy recommendations.Through a preliminary survey,we identified social stigma,social isolation,lack of healthcare facilities,and domestic violence as the potential reasons for suicidal ideation.We identified individuals with suicide ideation for further data collection to test the relationships between the identified variables and suicidal ideation.A quantitative,explanatory and cross-sectional design was used to test the hypotheses.Inferential statistics were applied to the data containing 314 responses,and the results revealed that all the predictive variables influence the formation of suicidal ideation.The study uncovered some new dimensions of social stigma and social isolation that are common among the indigenous people.The results also indicate that some domestic violence is socially acceptable and considered a normal familial matter.Thefindings have theoretical and practical implications.We have identified new dimensions of social stigma,social isolation,and domestic violence that are new additions to the existing bank of literature.It provides insights to encourage public authorities,healthcare providers,and NGO managers to play their role in the right direction to mitigate the problem.This study opens further venues for researchers to investigate the complex issue of suicide more deeply.展开更多
The present work emphasizes the significance of oscillatory mixed convection stratified fluid and heat transfer characteristics at different stations of non-conducting horizontally circular cylinder in the presence of...The present work emphasizes the significance of oscillatory mixed convection stratified fluid and heat transfer characteristics at different stations of non-conducting horizontally circular cylinder in the presence of thermally stratified medium.To remove the difficulties in illustrating the coupled PDE’s,the finite-difference scheme with efficient primitive-variable formulation is proposed to transform dimensionless equations.The numerical simulations of coupled non-dimensional equations are computed in terms velocity of fluid,temperature and magnetic field which are computed to examine the fluctuating components of skin friction,heat transfer and current density for various emerging parameters.The governing parameters namely,thermally stratification parameter𝑆𝑆𝑡𝑡,mixed-convection parameter𝜆𝜆,Prandtl number Pr,magnetic force parameter𝜉𝜉and magnetic-Prandtl number𝛾𝛾are displayed graphically at selected values for velocity and heat transfer mechanism.It is computed that heat transfer attains maximum amplitude and good variations in the presence of thermally stratified parameter at each position𝛼𝛼=𝜋𝜋6⁄,𝛼𝛼=𝜋𝜋3⁄and𝛼𝛼=𝜋𝜋around the surface of non-conducting horizontally cylinder.The velocity of fluid attains certain height at station𝛼𝛼=𝜋𝜋6⁄for higher value of stratification parameter.It is also found that the temperature gradient decreases with stratification parameter𝑆𝑆𝑡𝑡,but it increases after a certain distance𝑌𝑌from the cylinder.The novelty of the current work is that due to non-conducting phenomena the magnetic effects are strongly observed far from the surface but exact at the surface are zero for each position.展开更多
Facial expression recognition has been a hot topic for decades,but high intraclass variation makes it challenging.To overcome intraclass variation for visual recognition,we introduce a novel fusion methodology,in whic...Facial expression recognition has been a hot topic for decades,but high intraclass variation makes it challenging.To overcome intraclass variation for visual recognition,we introduce a novel fusion methodology,in which the proposed model first extract features followed by feature fusion.Specifically,RestNet-50,VGG-19,and Inception-V3 is used to ensure feature learning followed by feature fusion.Finally,the three feature extraction models are utilized using Ensemble Learning techniques for final expression classification.The representation learnt by the proposed methodology is robust to occlusions and pose variations and offers promising accuracy.To evaluate the efficiency of the proposed model,we use two wild benchmark datasets Real-world Affective Faces Database(RAF-DB)and AffectNet for facial expression recognition.The proposed model classifies the emotions into seven different categories namely:happiness,anger,fear,disgust,sadness,surprise,and neutral.Furthermore,the performance of the proposed model is also compared with other algorithms focusing on the analysis of computational cost,convergence and accuracy based on a standard problem specific to classification applications.展开更多
Bipolar medium-voltage DC(MVDC)and lowvoltage DC(LVDC)grids have the advantages of flexible integration of distributed renewable-energy generation and reliable power supply.In order to achieve voltage conversion,power...Bipolar medium-voltage DC(MVDC)and lowvoltage DC(LVDC)grids have the advantages of flexible integration of distributed renewable-energy generation and reliable power supply.In order to achieve voltage conversion,power transfer,and electrical isolation for bipolar MVDC and LVDC grids,a high-power DC-DC converter is essential.Therefore,this paper proposes an isolated bipolar modular multilevel DCDC converter(BiMMDC)with power self-balancing capability for interconnection of MVDC and LVDC grids.The proposed BiMMDC consists of two series connected MMCs in the MV stage to configure a bipolar MVDC interface,and interleaved converters combined with a dual-transformer are designed in the LV stage to configure the bipolar LVDC interface and to provide a self-balancing capability.Equivalent circuits of two series-connected MMCs and a dual-transformer with interleaved converters are derived.After that,operation principles of the proposed BiMMDC are introduced,considering balanced/unbalanced power transfer of bipolar LVDC grid and monopolar shortcircuit or open-circuit faults at MVDC grid.The control scheme is also presented for the proposed BiMMDC under different operating conditions.Finally,a Matlab simulation and controller hardware-in-the-loop(CHIL)evaluation results are provided to validate the feasibility and effectiveness of the proposed typology and its operating performance.展开更多
文摘The rapid evolution of wireless communication technologies has underscored the critical role of antennas in ensuring seamless connectivity.Antenna defects,ranging from manufacturing imperfections to environmental wear,pose significant challenges to the reliability and performance of communication systems.This review paper navigates the landscape of antenna defect detection,emphasizing the need for a nuanced understanding of various defect types and the associated challenges in visual detection.This review paper serves as a valuable resource for researchers,engineers,and practitioners engaged in the design and maintenance of communication systems.The insights presented here pave the way for enhanced reliability in antenna systems through targeted defect detection measures.In this study,a comprehensive literature analysis on computer vision algorithms that are employed in end-of-line visual inspection of antenna parts is presented.The PRISMA principles will be followed throughout the review,and its goals are to provide a summary of recent research,identify relevant computer vision techniques,and evaluate how effective these techniques are in discovering defects during inspections.It contains articles from scholarly journals as well as papers presented at conferences up until June 2023.This research utilized search phrases that were relevant,and papers were chosen based on whether or not they met certain inclusion and exclusion criteria.In this study,several different computer vision approaches,such as feature extraction and defect classification,are broken down and analyzed.Additionally,their applicability and performance are discussed.The review highlights the significance of utilizing a wide variety of datasets and measurement criteria.The findings of this study add to the existing body of knowledge and point researchers in the direction of promising new areas of investigation,such as real-time inspection systems and multispectral imaging.This review,on its whole,offers a complete study of computer vision approaches for quality control in antenna parts.It does so by providing helpful insights and drawing attention to areas that require additional exploration.
基金supported by Institute of Information&Communications Technology Planning&Evaluation(IITP)under the Metaverse Support Program to Nurture the Best Talents(IITP-2023-RS-2023-00254529)grant funded by the Korea government(MSIT).
文摘Apart from socio-economic disparities,indigenous people of the Himalayan range in Asia face an increasing trend of suicides.The tragic suicidal events usually go unaddressed,and no strategies are presently in place to mitigate suicides in the future.This study aims to explain the prevailing causes of suicidal ideation to come up with some policy recommendations.Through a preliminary survey,we identified social stigma,social isolation,lack of healthcare facilities,and domestic violence as the potential reasons for suicidal ideation.We identified individuals with suicide ideation for further data collection to test the relationships between the identified variables and suicidal ideation.A quantitative,explanatory and cross-sectional design was used to test the hypotheses.Inferential statistics were applied to the data containing 314 responses,and the results revealed that all the predictive variables influence the formation of suicidal ideation.The study uncovered some new dimensions of social stigma and social isolation that are common among the indigenous people.The results also indicate that some domestic violence is socially acceptable and considered a normal familial matter.Thefindings have theoretical and practical implications.We have identified new dimensions of social stigma,social isolation,and domestic violence that are new additions to the existing bank of literature.It provides insights to encourage public authorities,healthcare providers,and NGO managers to play their role in the right direction to mitigate the problem.This study opens further venues for researchers to investigate the complex issue of suicide more deeply.
文摘The present work emphasizes the significance of oscillatory mixed convection stratified fluid and heat transfer characteristics at different stations of non-conducting horizontally circular cylinder in the presence of thermally stratified medium.To remove the difficulties in illustrating the coupled PDE’s,the finite-difference scheme with efficient primitive-variable formulation is proposed to transform dimensionless equations.The numerical simulations of coupled non-dimensional equations are computed in terms velocity of fluid,temperature and magnetic field which are computed to examine the fluctuating components of skin friction,heat transfer and current density for various emerging parameters.The governing parameters namely,thermally stratification parameter𝑆𝑆𝑡𝑡,mixed-convection parameter𝜆𝜆,Prandtl number Pr,magnetic force parameter𝜉𝜉and magnetic-Prandtl number𝛾𝛾are displayed graphically at selected values for velocity and heat transfer mechanism.It is computed that heat transfer attains maximum amplitude and good variations in the presence of thermally stratified parameter at each position𝛼𝛼=𝜋𝜋6⁄,𝛼𝛼=𝜋𝜋3⁄and𝛼𝛼=𝜋𝜋around the surface of non-conducting horizontally cylinder.The velocity of fluid attains certain height at station𝛼𝛼=𝜋𝜋6⁄for higher value of stratification parameter.It is also found that the temperature gradient decreases with stratification parameter𝑆𝑆𝑡𝑡,but it increases after a certain distance𝑌𝑌from the cylinder.The novelty of the current work is that due to non-conducting phenomena the magnetic effects are strongly observed far from the surface but exact at the surface are zero for each position.
文摘Facial expression recognition has been a hot topic for decades,but high intraclass variation makes it challenging.To overcome intraclass variation for visual recognition,we introduce a novel fusion methodology,in which the proposed model first extract features followed by feature fusion.Specifically,RestNet-50,VGG-19,and Inception-V3 is used to ensure feature learning followed by feature fusion.Finally,the three feature extraction models are utilized using Ensemble Learning techniques for final expression classification.The representation learnt by the proposed methodology is robust to occlusions and pose variations and offers promising accuracy.To evaluate the efficiency of the proposed model,we use two wild benchmark datasets Real-world Affective Faces Database(RAF-DB)and AffectNet for facial expression recognition.The proposed model classifies the emotions into seven different categories namely:happiness,anger,fear,disgust,sadness,surprise,and neutral.Furthermore,the performance of the proposed model is also compared with other algorithms focusing on the analysis of computational cost,convergence and accuracy based on a standard problem specific to classification applications.
基金This work was supported in part by the National Natural Science Foundation of China(No.51877089)。
文摘Bipolar medium-voltage DC(MVDC)and lowvoltage DC(LVDC)grids have the advantages of flexible integration of distributed renewable-energy generation and reliable power supply.In order to achieve voltage conversion,power transfer,and electrical isolation for bipolar MVDC and LVDC grids,a high-power DC-DC converter is essential.Therefore,this paper proposes an isolated bipolar modular multilevel DCDC converter(BiMMDC)with power self-balancing capability for interconnection of MVDC and LVDC grids.The proposed BiMMDC consists of two series connected MMCs in the MV stage to configure a bipolar MVDC interface,and interleaved converters combined with a dual-transformer are designed in the LV stage to configure the bipolar LVDC interface and to provide a self-balancing capability.Equivalent circuits of two series-connected MMCs and a dual-transformer with interleaved converters are derived.After that,operation principles of the proposed BiMMDC are introduced,considering balanced/unbalanced power transfer of bipolar LVDC grid and monopolar shortcircuit or open-circuit faults at MVDC grid.The control scheme is also presented for the proposed BiMMDC under different operating conditions.Finally,a Matlab simulation and controller hardware-in-the-loop(CHIL)evaluation results are provided to validate the feasibility and effectiveness of the proposed typology and its operating performance.