In this article,a graphic design method for broadband Doherty power amplifier(DPA) is proposed based on the basic principle of impedance matching with the help of Smith chart.The proposed graphic method avoids the com...In this article,a graphic design method for broadband Doherty power amplifier(DPA) is proposed based on the basic principle of impedance matching with the help of Smith chart.The proposed graphic method avoids the complex formula derivation in the traditional amplifier circuit design process,and the design process is more simple and intuitive.Besides,it only takes three steps to build the load modulation network(LMN) of two power amplifiers(PA) of the DPA.Besides,a capacitor is used to replace the parasitic parameters of the transistor,and the LMN designed in the two modes is used for exploration and comparison.Further more,the output impedance of the peaking PA is introduced to make the reflection coefficient trajectory on Smith chart lowfrequency dispersion so as to expand the bandwidth of the DPA at the output power back-off(OBO) level.It would not affect the performance of DPA in the saturation(SAT) state.In this way,a broadband DPA can be implemented easily.To validate the proposed design method,a broadband DPA operating from 1.9to 2.6 GHz is designed and measured based on the proposed method.Under the continuous-wave excitation,the fabricated DPA has a 6 dB OBO efficiency of 48%-56% and a SAT efficiency of 64%-73% from 1.75 to 2.45 GHz,and the peak output power is 48.9-49.8 dBm.展开更多
It is of great scientific significance to construct a 3D dynamic structural color with a special color effect based on the microlens array.However,the problems of imperfect mechanisms and poor color quality need to be...It is of great scientific significance to construct a 3D dynamic structural color with a special color effect based on the microlens array.However,the problems of imperfect mechanisms and poor color quality need to be solved.A method of 3D structural color turning on periodic metasurfaces fabricated by the microlens array and self-assembly technology was proposed in this study.In the experiment,Polydimethylsiloxane(PDMS)flexible film was used as a substrate,and SiO2 microspheres were scraped into grooves of the PDMS film to form 3D photonic crystal structures.By adjusting the number of blade-coated times and microsphere concentrations,high-saturation structural color micropatterns were obtained.These films were then matched with microlens arrays to produce dynamic graphics with iridescent effects.The results showed that by blade-coated two times and SiO2 microsphere concentrations of 50%are the best conditions.This method demonstrates the potential for being widely applied in the anticounterfeiting printing and ultra-high-resolution display.展开更多
Graphical abstracts(GAs)are emerging as a pivotal tool in medical literature,enhancing the dissemination and comprehension of complex clinical data through visual summaries.This editorial highlights the significant ad...Graphical abstracts(GAs)are emerging as a pivotal tool in medical literature,enhancing the dissemination and comprehension of complex clinical data through visual summaries.This editorial highlights the significant advantages of GAs,including improved clarity,increased reader engagement,and enhanced visibility of research findings.By transforming intricate scientific data into accessible visual formats,these abstracts facilitate quick and effective knowledge transfer,crucial in clinical decision-making and patient care.However,challenges such as potential data misrepresentation due to oversimplification,the skill gap in graphic design among researchers,and the lack of standardized creation guidelines pose barriers to their widespread adoption.Additionally,while software such as Adobe Illustrator,BioRender,and Canva are commonly employed to create these visuals,not all researchers may be proficient in their use.To address these issues,we recommend that academic journals establish clear guidelines and provide necessary design training to researchers.This proactive approach will ensure the creation of high-quality GAs,promote their standardization,and expand their use in clinical reporting,ultimately benefiting the medical community and improving healthcare outcomes.展开更多
Conception of graphic art,is widely increased in nowadays,because of persistent acquire of new ideas and art practices,which is key feature of modern art.As a result,variety of graphic art grew heavily-constantly acqu...Conception of graphic art,is widely increased in nowadays,because of persistent acquire of new ideas and art practices,which is key feature of modern art.As a result,variety of graphic art grew heavily-constantly acquiring new aspects and experimenting with new materials,but also not forgetting about classic techniques of graphic art.That is why Latvia’s contemporary art is rich with outstanding graphics artists,which is masters of their profession.But time goes and everything sees it’s end,and on Latvia’s art horizon start to appear new faces and new talents of Latvia’s graphics art,which already had their opportunity to demonstrate highest level of their mastery and creativity,not only in Latvia,but also on international level.Living in a rhythm of modern fast-paced technology and innovation era,Latvia’s graphic artists,still say“Yes!”,to classic techniques of graphic art-linocutting,lithography and drypointing.However,they are open-minded persons and like to experiment with new techniques(for example-digiprint),or if it is suitable for their idea-combine them,to reach their goal.Aim of this paper is to get acquainted with Latvia’s next-gen graphic artists,their ideas and views,as well with results of their creative,acquiring brief review of Latvia’s graphic trends in general.As a result reader will become familiar not only with Latvia’s domestic artists and their creativity,but also will get general review of the current trends in the world of graphic art,which is not only classic,but also very innovative,regarding of new materials and techniques.展开更多
Authentication is the most crucial aspect of security and a predominant measure employed in cybersecurity.Cloud computing provides a shared electronic device resource for users via the internet,and the authentication ...Authentication is the most crucial aspect of security and a predominant measure employed in cybersecurity.Cloud computing provides a shared electronic device resource for users via the internet,and the authentication techniques used must protect data from attacks.Previous approaches failed to resolve the challenge of making passwords secure,memorable,usable,and time-saving.Graphical Password(GP)is still not widely utilized in reality because consumers suffer from multiple login stages.This paper proposes an Indexed Choice-Based Graphical Password(ICGP)scheme for improving the authentication part.ICGP consists of two stages:registration and authentication.At the registration stage,the user registers his/her data user name a number called Index Number(IN),and chooses an image from a grid of images.After completing the registration,ICGP gives the user a random unique number(UNo)to be a user ID.At the authentication stage,the user chooses a different image from the grid based on the random appearance of the registered image dimensions on the grid plus the registered Index Number.ICGP password is a combination of three factors;user’s name,UNo,and any image.According to the experiments,the proposed ICGP has achieved great improvements when compared to prior methods.The ICGP has increased the possible password numbers from 9.77e+6 to 3.74e+30,the password space from 1.20e+34 to 1.37e+84,and decreased the password entropy from 7.16e−7 to 8.26e−30.展开更多
The rapid expansion of offshore wind energy necessitates robust and cost-effective electrical collector system(ECS)designs that prioritize lifetime operational reliability.Traditional optimization approaches often sim...The rapid expansion of offshore wind energy necessitates robust and cost-effective electrical collector system(ECS)designs that prioritize lifetime operational reliability.Traditional optimization approaches often simplify reliability considerations or fail to holistically integrate them with economic and technical constraints.This paper introduces a novel,two-stage optimization framework for offshore wind farm(OWF)ECS planning that systematically incorporates reliability.The first stage employs Mixed-Integer Linear Programming(MILP)to determine an optimal radial network topology,considering linearized reliability approximations and geographical constraints.The second stage enhances this design by strategically placing tie-lines using a Mixed-Integer Quadratically Constrained Program(MIQCP).This stage leverages a dynamic-aware adaptation of Multi-Source Multi-Terminal Network Reliability(MSMT-NR)assessment,with its inherent nonlinear equations successfully transformed into a solvable MIQCP form for loopy networks.A benchmark case study demonstrates the framework’s efficacy,illustrating how increasing the emphasis on reliability leads to more distributed and interconnected network topologies,effectively balancing investment costs against enhanced system resilience.展开更多
The newly emerging neural radiance fields(NeRF)methods can implicitly fulfill three-dimensional(3D)reconstruction via training a neural network to render novel-view images of a given scene with given posed images.The ...The newly emerging neural radiance fields(NeRF)methods can implicitly fulfill three-dimensional(3D)reconstruction via training a neural network to render novel-view images of a given scene with given posed images.The Instant Neural Graphics Primitives(Instant-NGP)method further improves the position encoding of NeRF.It obtains state-of-the-art efficiency.However,only a local pixel-wised loss is considered when training the Instant-NGP while overlooking the nonlocal structural information between pixels.Despite a good quantitative result,it leads to a poor visual effect,especially the completeness.Inspired by the stochastic structural similarity(S3IM)method that exploits nonlocal structural information of groups of pixels,this paper proposes a new method to improve the completeness of fast novel view synthesis.The proposed method first extends the thread-wised processing of the Instant-NGP to the processing in a customthread block(i.e.,a group of threads).Then,the relative dimensionless global error in synthesis,i.e.,Erreur Relative Globale Adimensionnelle de Synthese(ERGAS),of a group of pixels corresponding to a group of threads is computed and incorporated into the loss function.Extensive experiments validate the proposed method.It can obtain better quantitative results than the original Instant-NGP with fewer iteration steps.PSNR is increased by 1%.Amazing qualitative results are obtained,especially for delicate structures and details such as lines and continuous structures.With the dramatic improvements in the visual effects,our method can boost the practicability of implicit 3D reconstruction in applications such as self-driving and augmented reality.展开更多
In the context of the deep integration of digitalization and innovation and entrepreneurship education,this study focuses on the characteristics of schools and courses,investigates students’expectations and needs for...In the context of the deep integration of digitalization and innovation and entrepreneurship education,this study focuses on the characteristics of schools and courses,investigates students’expectations and needs for ideological and political elements,and deeply explores ideological and political cases such as the Beidahuang spirit,Daqing spirit,model worker spirit,and role models around them.It explores the integration practice of“curriculum ideological and political”in extracurricular tutoring teaching of engineering graphics,aiming to guide students to establish patriotism,love for schools,knowledge of agriculture,and love for agriculture,and effectively enhance the coordinated development of students’graphic skills and ideological and political literacy.Practice has shown that integrating ideological and political resources,incorporating ideological and political elements into curriculum content and practical activities,can effectively enhance the collaborative development of students’graphic skills and ideological and political literacy.At the same time,it provides new ideas and references for expanding ideological and political education to extracurricular tutoring courses.展开更多
稀疏矩阵向量乘(SpMV)是稀疏线性系统的计算核心和瓶颈,其运算效率会影响迭代求解器的整体性能,其优化研究一直是科学计算和工程应用领域中的研究热点之一。偏微分方程的离散化会产生稀疏对角矩阵,由于其多样的非零元分布,导致没有一种...稀疏矩阵向量乘(SpMV)是稀疏线性系统的计算核心和瓶颈,其运算效率会影响迭代求解器的整体性能,其优化研究一直是科学计算和工程应用领域中的研究热点之一。偏微分方程的离散化会产生稀疏对角矩阵,由于其多样的非零元分布,导致没有一种方法能够在所有矩阵中取得最优时间性能。针对上述问题,提出一种面向图形处理单元(GPU)的稀疏对角矩阵自适应SpMV优化方法AST(Adaptive SpMV Tuning)。该方法通过设计特征空间,构建特征提取器,提取矩阵结构精细特征,通过深入分析特征和SpMV方法的相关性,建立可扩展的候选方法集合,形成特征和最优方法的映射关系,构建性能预测工具,实现矩阵最优方法的高效预测。实验结果表明,AST能够取得85.8%的预测准确率,平均时间性能损失为0.09,相比于DIA(Diagonal)、HDIA(Hacked DIA)、HDC(Hybrid of DIA and Compressed Sparse Row)、DIA-Adaptive和DRM(Divide-Rearrange and Merge),能够获得平均20.19、1.86、3.06、3.72和1.53倍的内核运行时间加速和1.05、1.28、12.45、1.94和0.97倍的浮点运算性能加速。展开更多
基金National Natural Science Foundation of China (No. 62001061)。
文摘In this article,a graphic design method for broadband Doherty power amplifier(DPA) is proposed based on the basic principle of impedance matching with the help of Smith chart.The proposed graphic method avoids the complex formula derivation in the traditional amplifier circuit design process,and the design process is more simple and intuitive.Besides,it only takes three steps to build the load modulation network(LMN) of two power amplifiers(PA) of the DPA.Besides,a capacitor is used to replace the parasitic parameters of the transistor,and the LMN designed in the two modes is used for exploration and comparison.Further more,the output impedance of the peaking PA is introduced to make the reflection coefficient trajectory on Smith chart lowfrequency dispersion so as to expand the bandwidth of the DPA at the output power back-off(OBO) level.It would not affect the performance of DPA in the saturation(SAT) state.In this way,a broadband DPA can be implemented easily.To validate the proposed design method,a broadband DPA operating from 1.9to 2.6 GHz is designed and measured based on the proposed method.Under the continuous-wave excitation,the fabricated DPA has a 6 dB OBO efficiency of 48%-56% and a SAT efficiency of 64%-73% from 1.75 to 2.45 GHz,and the peak output power is 48.9-49.8 dBm.
文摘It is of great scientific significance to construct a 3D dynamic structural color with a special color effect based on the microlens array.However,the problems of imperfect mechanisms and poor color quality need to be solved.A method of 3D structural color turning on periodic metasurfaces fabricated by the microlens array and self-assembly technology was proposed in this study.In the experiment,Polydimethylsiloxane(PDMS)flexible film was used as a substrate,and SiO2 microspheres were scraped into grooves of the PDMS film to form 3D photonic crystal structures.By adjusting the number of blade-coated times and microsphere concentrations,high-saturation structural color micropatterns were obtained.These films were then matched with microlens arrays to produce dynamic graphics with iridescent effects.The results showed that by blade-coated two times and SiO2 microsphere concentrations of 50%are the best conditions.This method demonstrates the potential for being widely applied in the anticounterfeiting printing and ultra-high-resolution display.
文摘Graphical abstracts(GAs)are emerging as a pivotal tool in medical literature,enhancing the dissemination and comprehension of complex clinical data through visual summaries.This editorial highlights the significant advantages of GAs,including improved clarity,increased reader engagement,and enhanced visibility of research findings.By transforming intricate scientific data into accessible visual formats,these abstracts facilitate quick and effective knowledge transfer,crucial in clinical decision-making and patient care.However,challenges such as potential data misrepresentation due to oversimplification,the skill gap in graphic design among researchers,and the lack of standardized creation guidelines pose barriers to their widespread adoption.Additionally,while software such as Adobe Illustrator,BioRender,and Canva are commonly employed to create these visuals,not all researchers may be proficient in their use.To address these issues,we recommend that academic journals establish clear guidelines and provide necessary design training to researchers.This proactive approach will ensure the creation of high-quality GAs,promote their standardization,and expand their use in clinical reporting,ultimately benefiting the medical community and improving healthcare outcomes.
文摘Conception of graphic art,is widely increased in nowadays,because of persistent acquire of new ideas and art practices,which is key feature of modern art.As a result,variety of graphic art grew heavily-constantly acquiring new aspects and experimenting with new materials,but also not forgetting about classic techniques of graphic art.That is why Latvia’s contemporary art is rich with outstanding graphics artists,which is masters of their profession.But time goes and everything sees it’s end,and on Latvia’s art horizon start to appear new faces and new talents of Latvia’s graphics art,which already had their opportunity to demonstrate highest level of their mastery and creativity,not only in Latvia,but also on international level.Living in a rhythm of modern fast-paced technology and innovation era,Latvia’s graphic artists,still say“Yes!”,to classic techniques of graphic art-linocutting,lithography and drypointing.However,they are open-minded persons and like to experiment with new techniques(for example-digiprint),or if it is suitable for their idea-combine them,to reach their goal.Aim of this paper is to get acquainted with Latvia’s next-gen graphic artists,their ideas and views,as well with results of their creative,acquiring brief review of Latvia’s graphic trends in general.As a result reader will become familiar not only with Latvia’s domestic artists and their creativity,but also will get general review of the current trends in the world of graphic art,which is not only classic,but also very innovative,regarding of new materials and techniques.
基金Supporting Project number(RSP2024R444),King Saud University,Riyadh,Saudi Arabia.
文摘Authentication is the most crucial aspect of security and a predominant measure employed in cybersecurity.Cloud computing provides a shared electronic device resource for users via the internet,and the authentication techniques used must protect data from attacks.Previous approaches failed to resolve the challenge of making passwords secure,memorable,usable,and time-saving.Graphical Password(GP)is still not widely utilized in reality because consumers suffer from multiple login stages.This paper proposes an Indexed Choice-Based Graphical Password(ICGP)scheme for improving the authentication part.ICGP consists of two stages:registration and authentication.At the registration stage,the user registers his/her data user name a number called Index Number(IN),and chooses an image from a grid of images.After completing the registration,ICGP gives the user a random unique number(UNo)to be a user ID.At the authentication stage,the user chooses a different image from the grid based on the random appearance of the registered image dimensions on the grid plus the registered Index Number.ICGP password is a combination of three factors;user’s name,UNo,and any image.According to the experiments,the proposed ICGP has achieved great improvements when compared to prior methods.The ICGP has increased the possible password numbers from 9.77e+6 to 3.74e+30,the password space from 1.20e+34 to 1.37e+84,and decreased the password entropy from 7.16e−7 to 8.26e−30.
基金supported by the Science and Technology Project of China South Power Grid Co.,Ltd.,Grant Nos.036000KK52222044,GDKJXM20222430。
文摘The rapid expansion of offshore wind energy necessitates robust and cost-effective electrical collector system(ECS)designs that prioritize lifetime operational reliability.Traditional optimization approaches often simplify reliability considerations or fail to holistically integrate them with economic and technical constraints.This paper introduces a novel,two-stage optimization framework for offshore wind farm(OWF)ECS planning that systematically incorporates reliability.The first stage employs Mixed-Integer Linear Programming(MILP)to determine an optimal radial network topology,considering linearized reliability approximations and geographical constraints.The second stage enhances this design by strategically placing tie-lines using a Mixed-Integer Quadratically Constrained Program(MIQCP).This stage leverages a dynamic-aware adaptation of Multi-Source Multi-Terminal Network Reliability(MSMT-NR)assessment,with its inherent nonlinear equations successfully transformed into a solvable MIQCP form for loopy networks.A benchmark case study demonstrates the framework’s efficacy,illustrating how increasing the emphasis on reliability leads to more distributed and interconnected network topologies,effectively balancing investment costs against enhanced system resilience.
基金supported in part by National Natural Science Foundation of China under Grant No.62473013Key Project of Science and Technology Innovation and Entrepreneurship of TDTEC(No.2022-TDZD004).
文摘The newly emerging neural radiance fields(NeRF)methods can implicitly fulfill three-dimensional(3D)reconstruction via training a neural network to render novel-view images of a given scene with given posed images.The Instant Neural Graphics Primitives(Instant-NGP)method further improves the position encoding of NeRF.It obtains state-of-the-art efficiency.However,only a local pixel-wised loss is considered when training the Instant-NGP while overlooking the nonlocal structural information between pixels.Despite a good quantitative result,it leads to a poor visual effect,especially the completeness.Inspired by the stochastic structural similarity(S3IM)method that exploits nonlocal structural information of groups of pixels,this paper proposes a new method to improve the completeness of fast novel view synthesis.The proposed method first extends the thread-wised processing of the Instant-NGP to the processing in a customthread block(i.e.,a group of threads).Then,the relative dimensionless global error in synthesis,i.e.,Erreur Relative Globale Adimensionnelle de Synthese(ERGAS),of a group of pixels corresponding to a group of threads is computed and incorporated into the loss function.Extensive experiments validate the proposed method.It can obtain better quantitative results than the original Instant-NGP with fewer iteration steps.PSNR is increased by 1%.Amazing qualitative results are obtained,especially for delicate structures and details such as lines and continuous structures.With the dramatic improvements in the visual effects,our method can boost the practicability of implicit 3D reconstruction in applications such as self-driving and augmented reality.
基金financed by Project of Heilongjiang Higher Education Society“Research on Graphics Curriculum Based on Innovation and Entrepreneurship Education under the Background of Digital Education”(23GJYB035)the 2024 Annual Planning Project of the“14th Five Year Plan”of Educational Science in Heilongjiang Province“Research and Exploration on Ideological and Political Teaching of‘Computer Graphics’Course under the Concept of OBE in New Engineering”(GJB1424113).
文摘In the context of the deep integration of digitalization and innovation and entrepreneurship education,this study focuses on the characteristics of schools and courses,investigates students’expectations and needs for ideological and political elements,and deeply explores ideological and political cases such as the Beidahuang spirit,Daqing spirit,model worker spirit,and role models around them.It explores the integration practice of“curriculum ideological and political”in extracurricular tutoring teaching of engineering graphics,aiming to guide students to establish patriotism,love for schools,knowledge of agriculture,and love for agriculture,and effectively enhance the coordinated development of students’graphic skills and ideological and political literacy.Practice has shown that integrating ideological and political resources,incorporating ideological and political elements into curriculum content and practical activities,can effectively enhance the collaborative development of students’graphic skills and ideological and political literacy.At the same time,it provides new ideas and references for expanding ideological and political education to extracurricular tutoring courses.
文摘稀疏矩阵向量乘(SpMV)是稀疏线性系统的计算核心和瓶颈,其运算效率会影响迭代求解器的整体性能,其优化研究一直是科学计算和工程应用领域中的研究热点之一。偏微分方程的离散化会产生稀疏对角矩阵,由于其多样的非零元分布,导致没有一种方法能够在所有矩阵中取得最优时间性能。针对上述问题,提出一种面向图形处理单元(GPU)的稀疏对角矩阵自适应SpMV优化方法AST(Adaptive SpMV Tuning)。该方法通过设计特征空间,构建特征提取器,提取矩阵结构精细特征,通过深入分析特征和SpMV方法的相关性,建立可扩展的候选方法集合,形成特征和最优方法的映射关系,构建性能预测工具,实现矩阵最优方法的高效预测。实验结果表明,AST能够取得85.8%的预测准确率,平均时间性能损失为0.09,相比于DIA(Diagonal)、HDIA(Hacked DIA)、HDC(Hybrid of DIA and Compressed Sparse Row)、DIA-Adaptive和DRM(Divide-Rearrange and Merge),能够获得平均20.19、1.86、3.06、3.72和1.53倍的内核运行时间加速和1.05、1.28、12.45、1.94和0.97倍的浮点运算性能加速。
