A novel negative thermal expansion(NTE) material NdMnO_(3) was synthesized by solid-state method at 1 523 K. The crystal structure, phase transition, pores effect and negative expansion properties of NdMnO_(3) were in...A novel negative thermal expansion(NTE) material NdMnO_(3) was synthesized by solid-state method at 1 523 K. The crystal structure, phase transition, pores effect and negative expansion properties of NdMnO_(3) were investigated by variable temperature X-ray diffraction(XRD), scanning electron microscope(SEM) and variable temperature Raman spectra. The compound exhibits NTE properties in the orderly O' phase crystal structure. When the temperature is from 293 to 759 K, the ceramic NdMnO_(3) shows negative thermal expansion of-4.7×10^(-6)/K. As temperature increases, the ceramic NdMnO_(3) presents NTE property range from 759 to 1 007 K. The average linear expansion coefficient is-18.88×10^(-6)/K. The physical mechanism of NTE is discussed and clarified through experiments.展开更多
Space solar power(SSP)system,a major type of space-based power-generating equipment,is an important infrastructure providing massive,continuous,and stable green electricity by utilizing solar energy in space.Many coun...Space solar power(SSP)system,a major type of space-based power-generating equipment,is an important infrastructure providing massive,continuous,and stable green electricity by utilizing solar energy in space.Many countries and organizations consider SSP to be one of the most promising clean energy sources.The historical activities of SSP in the world are summarized.This review focuses on the significant development of SSP during the last 10 years,which is the most important period for SSP.The latest international SSP development programmes in the United States,ESA,Japan,China,UK and Korea are presented.Some significant solar power satellite(SPS)concepts proposed in the decade,including typical SPS-ALPHA,MR-SPS,CASSIOPeiA SPS,et al.,are introduced.The technical and non-technical challenges are also listed and several important in-space demonstration missions in recent years and in the near future are introduced.The conclusion is that the next 5 to 10 years will be an important period for rapidly developing the key technologies and conducting on-orbit demonstration and application.Controlling the mutual position relationship between the solar array and the transmitting antenna becomes a core issue to be considered in the innovative design of the SPS.Wireless power transmission technologies would be the demonstration focus for the first step.It is expected that the first commercial SPS would be constructed as early as 2040.展开更多
Manual investigation of chest radiography(CXR)images by physicians is crucial for effective decision-making in COVID-19 diagnosis.However,the high demand during the pandemic necessitates auxiliary help through image a...Manual investigation of chest radiography(CXR)images by physicians is crucial for effective decision-making in COVID-19 diagnosis.However,the high demand during the pandemic necessitates auxiliary help through image analysis and machine learning techniques.This study presents a multi-threshold-based segmentation technique to probe high pixel intensity regions in CXR images of various pathologies,including normal cases.Texture information is extracted using gray co-occurrence matrix(GLCM)-based features,while vessel-like features are obtained using Frangi,Sato,and Meijering filters.Machine learning models employing Decision Tree(DT)and RandomForest(RF)approaches are designed to categorize CXR images into common lung infections,lung opacity(LO),COVID-19,and viral pneumonia(VP).The results demonstrate that the fusion of texture and vesselbased features provides an effective ML model for aiding diagnosis.The ML model validation using performance measures,including an accuracy of approximately 91.8%with an RF-based classifier,supports the usefulness of the feature set and classifier model in categorizing the four different pathologies.Furthermore,the study investigates the importance of the devised features in identifying the underlying pathology and incorporates histogrambased analysis.This analysis reveals varying natural pixel distributions in CXR images belonging to the normal,COVID-19,LO,and VP groups,motivating the incorporation of additional features such as mean,standard deviation,skewness,and percentile based on the filtered images.Notably,the study achieves a considerable improvement in categorizing COVID-19 from LO,with a true positive rate of 97%,further substantiating the effectiveness of the methodology implemented.展开更多
The laser technology has made remarkable progress over the past couple of decades.It is being widely employed in diverse domains,such as holography,space sciences,spectroscopy,medical sciences,micro and power electron...The laser technology has made remarkable progress over the past couple of decades.It is being widely employed in diverse domains,such as holography,space sciences,spectroscopy,medical sciences,micro and power electronics,industrial engineering,and most distinctively,as directed energy military weapons.Owing to their active transmissions,laser systems are similar to microwave radars to some extent;however,unlike conventional radars,the laser operates at very high frequencies thus making it a potent enabler of narrow-beam and high energy aerial deployments,both in offensive and defensive roles.In modern avionics systems,laser target indicators and beam riders are the most common devices that are used to direct the Laser Guided Weapons(LGW)accurately to the ground targets.Additionally,compact size and outstanding angular resolution of laser-based systems motivate their use for drones and unmanned aerial applications.Moreover,the narrow-beam divergence of laser emissions offers a low probability of intercept,making it a suitable contender for secure transmissions and safety-critical operations.Furthermore,the developments in space sciences and laser technology have given synergistic potential outcomes to use laser systems in space operations.This paper comprehensively reviews laser applications and projects for strategic defense actions on the ground or in space.Additionally,a detailed analysis has been done on recent advancements of the laser technology for target indicators and range-finders.It also reviews the advancements in the field of laser communications for surveillance,its earlier state of the art,and ongoing scientific research and advancements in the domain of high energy directed laser weapons that have revolutionized the evolving military battlefield.Besides offering a comprehensive taxonomy,the paper also critically analyzes some of the recent contributions in the associated domains.展开更多
Unmanned Aero Vehicles (UAV) has become a useful entity for quite a good number of industries and facilities. It is an agile, cost effective and reliable solution for communication, defense, security, delivery, survei...Unmanned Aero Vehicles (UAV) has become a useful entity for quite a good number of industries and facilities. It is an agile, cost effective and reliable solution for communication, defense, security, delivery, surveillance and surveying etc. However, their reliability is dependent on the resilient and stabilizes performance based on control systems embedded behind the body. Therefore, the UAV is majorly dependent upon controller design and the requirement of particular performance parameters. Nevertheless, in modern technologies there is always a room for improvement. In the similar manner a UAV lateral control system was implemented and researched in this study, which has been optimized using Proportional, Integral and Derivative (PID) controller, phase lead compensator and signal constraint controller. The significance of this study is the optimization of the existing UAV controller plant for improving lateral performance and stability. With this UAV community will benefit from designing robust controls using the optimized method utilized in this paper and moreover this will provide sophisticated control to operate in unpredictable environments. It is observed that results obtained for optimized lateral control dynamics using phase lead compensator (PLC) are efficacious than the simple PID feedback gains. However, for optimizing unwanted signals of lateral velocity, yaw rate, and yaw angle modes, PLC were integrated with PID to achieve dynamical stability.展开更多
Despite the development of newer oncological treatment,the survival of patients with pancreatic cancer(PC)remains poor.Recent studies have identified exosomes as essential mediators of intercellular communications and...Despite the development of newer oncological treatment,the survival of patients with pancreatic cancer(PC)remains poor.Recent studies have identified exosomes as essential mediators of intercellular communications and play a vital role in tumor initiation,metastasis and chemoresistance.Thus,the utility of liquid biopsies using exosomes in PC management can be used for early detection,diagnosis,monitoring as well as drug delivery vehicles for cancer therapy.This review summarizes the function,and clinical applications of exosomes in cancers as minimally invasive liquid biomarker in diagnostic,prognostic and therapeutic roles.展开更多
Development of asymptotic magnitude Bode plots for integer-order transfer functions is a well-established topic in the control theory.However,construction of such plots for the fractional-order transfer functions has ...Development of asymptotic magnitude Bode plots for integer-order transfer functions is a well-established topic in the control theory.However,construction of such plots for the fractional-order transfer functions has not received much attention in the existing literature.In the present paper,we investigate in this direction and derive the procedures for sketching asymptotic magnitude Bode plots for some of the popular fractional-order controllers such as PI^α,[PI]^α,PD^β,[PD]^β,and PI^αD^β.In addition,we deduce these plots for general fractional commensurate-order transfer functions as well.As applications of this work,we illustrate 1)the analysis of the designed fractional-control loop and 2)the identification of fractional-order transfer function from a given plot.展开更多
Cancer is a disease that is rapidly expanding in prevalence all over the world.Cancer cells canmetastasize,or spread,across the body and impact several different cell types.Additionally,the incidence rates of several ...Cancer is a disease that is rapidly expanding in prevalence all over the world.Cancer cells canmetastasize,or spread,across the body and impact several different cell types.Additionally,the incidence rates of several subtypes of cancer have been on the rise in India.The countermeasures for the cancer disease can be taken by determining the specific expansion rate of each type.To rank the various forms of cancer’s rate of progression,we used some of the available data.Numerous studies are available in the literature which show the growth rate of cancer by different techniques.The accuracy of the scheme in determining the highest growth rate may vary due to the variation in the dependent factors.Within the context of this research,the Fuzzy triangular technique for order preference by similarity to ideal solution(TOPSIS),is utilized to rank the various categorizations of cancer with the help of four groups of medical professionals acting in the capacity of decision-makers.The number of decision-makers may variate according to the required accuracy of results.The findings of the three-dimensional Fuzzy TOPSIS analysis categorize each variety of cancer according to the rate at which it spreads over time.Numerical results along with visual representation are presented to examine the efficiency of our proposed work.展开更多
In designing a modern home with a focus on the comfort of residents and energy usage optimization simultaneously,the rise of the Internet of Things and its incorporation with sensor technology plays a vital role these...In designing a modern home with a focus on the comfort of residents and energy usage optimization simultaneously,the rise of the Internet of Things and its incorporation with sensor technology plays a vital role these days.The first and foremost task is to predict the energy consumption based on the available data.This study investigates the integration of artificial neural networks in smart home technology to improve energy usage prediction and efficiency,without compromising the comfort of occupants.A dynamic model based on an artificial neural network model is designed in this study which artificially controls light,heating process,and cooling to cut down energy wastage.Energy consumption data of 114 single-family apartments was collected between 2014 and 2016.Energy consumption is predicted by the current model with an accuracy of up to 99.9%for energy usage patterns,which helps to optimize resource management in real time.A robust modeling approach i.e.multi-layer perceptron networks was implemented along with energy usage data.Seventy percent of the data is used for training the neural networks,and the rest is used for testing and validation purposes.The current defined model shows a significant improvement in prediction accuracy of energy usage and efficiency when compared to state-of-the-art models.Metrics such as R-values and mean square error are employed to check accuracy.These results show the essential role of artificial intelligence in improving energy management for smart buildings,with potential benefits including significant energy usage and loss management to help improve sustainable living.展开更多
文摘A novel negative thermal expansion(NTE) material NdMnO_(3) was synthesized by solid-state method at 1 523 K. The crystal structure, phase transition, pores effect and negative expansion properties of NdMnO_(3) were investigated by variable temperature X-ray diffraction(XRD), scanning electron microscope(SEM) and variable temperature Raman spectra. The compound exhibits NTE properties in the orderly O' phase crystal structure. When the temperature is from 293 to 759 K, the ceramic NdMnO_(3) shows negative thermal expansion of-4.7×10^(-6)/K. As temperature increases, the ceramic NdMnO_(3) presents NTE property range from 759 to 1 007 K. The average linear expansion coefficient is-18.88×10^(-6)/K. The physical mechanism of NTE is discussed and clarified through experiments.
基金Civil Aerospace Technology Research Project(D010103)。
文摘Space solar power(SSP)system,a major type of space-based power-generating equipment,is an important infrastructure providing massive,continuous,and stable green electricity by utilizing solar energy in space.Many countries and organizations consider SSP to be one of the most promising clean energy sources.The historical activities of SSP in the world are summarized.This review focuses on the significant development of SSP during the last 10 years,which is the most important period for SSP.The latest international SSP development programmes in the United States,ESA,Japan,China,UK and Korea are presented.Some significant solar power satellite(SPS)concepts proposed in the decade,including typical SPS-ALPHA,MR-SPS,CASSIOPeiA SPS,et al.,are introduced.The technical and non-technical challenges are also listed and several important in-space demonstration missions in recent years and in the near future are introduced.The conclusion is that the next 5 to 10 years will be an important period for rapidly developing the key technologies and conducting on-orbit demonstration and application.Controlling the mutual position relationship between the solar array and the transmitting antenna becomes a core issue to be considered in the innovative design of the SPS.Wireless power transmission technologies would be the demonstration focus for the first step.It is expected that the first commercial SPS would be constructed as early as 2040.
文摘Manual investigation of chest radiography(CXR)images by physicians is crucial for effective decision-making in COVID-19 diagnosis.However,the high demand during the pandemic necessitates auxiliary help through image analysis and machine learning techniques.This study presents a multi-threshold-based segmentation technique to probe high pixel intensity regions in CXR images of various pathologies,including normal cases.Texture information is extracted using gray co-occurrence matrix(GLCM)-based features,while vessel-like features are obtained using Frangi,Sato,and Meijering filters.Machine learning models employing Decision Tree(DT)and RandomForest(RF)approaches are designed to categorize CXR images into common lung infections,lung opacity(LO),COVID-19,and viral pneumonia(VP).The results demonstrate that the fusion of texture and vesselbased features provides an effective ML model for aiding diagnosis.The ML model validation using performance measures,including an accuracy of approximately 91.8%with an RF-based classifier,supports the usefulness of the feature set and classifier model in categorizing the four different pathologies.Furthermore,the study investigates the importance of the devised features in identifying the underlying pathology and incorporates histogrambased analysis.This analysis reveals varying natural pixel distributions in CXR images belonging to the normal,COVID-19,LO,and VP groups,motivating the incorporation of additional features such as mean,standard deviation,skewness,and percentile based on the filtered images.Notably,the study achieves a considerable improvement in categorizing COVID-19 from LO,with a true positive rate of 97%,further substantiating the effectiveness of the methodology implemented.
文摘The laser technology has made remarkable progress over the past couple of decades.It is being widely employed in diverse domains,such as holography,space sciences,spectroscopy,medical sciences,micro and power electronics,industrial engineering,and most distinctively,as directed energy military weapons.Owing to their active transmissions,laser systems are similar to microwave radars to some extent;however,unlike conventional radars,the laser operates at very high frequencies thus making it a potent enabler of narrow-beam and high energy aerial deployments,both in offensive and defensive roles.In modern avionics systems,laser target indicators and beam riders are the most common devices that are used to direct the Laser Guided Weapons(LGW)accurately to the ground targets.Additionally,compact size and outstanding angular resolution of laser-based systems motivate their use for drones and unmanned aerial applications.Moreover,the narrow-beam divergence of laser emissions offers a low probability of intercept,making it a suitable contender for secure transmissions and safety-critical operations.Furthermore,the developments in space sciences and laser technology have given synergistic potential outcomes to use laser systems in space operations.This paper comprehensively reviews laser applications and projects for strategic defense actions on the ground or in space.Additionally,a detailed analysis has been done on recent advancements of the laser technology for target indicators and range-finders.It also reviews the advancements in the field of laser communications for surveillance,its earlier state of the art,and ongoing scientific research and advancements in the domain of high energy directed laser weapons that have revolutionized the evolving military battlefield.Besides offering a comprehensive taxonomy,the paper also critically analyzes some of the recent contributions in the associated domains.
文摘Unmanned Aero Vehicles (UAV) has become a useful entity for quite a good number of industries and facilities. It is an agile, cost effective and reliable solution for communication, defense, security, delivery, surveillance and surveying etc. However, their reliability is dependent on the resilient and stabilizes performance based on control systems embedded behind the body. Therefore, the UAV is majorly dependent upon controller design and the requirement of particular performance parameters. Nevertheless, in modern technologies there is always a room for improvement. In the similar manner a UAV lateral control system was implemented and researched in this study, which has been optimized using Proportional, Integral and Derivative (PID) controller, phase lead compensator and signal constraint controller. The significance of this study is the optimization of the existing UAV controller plant for improving lateral performance and stability. With this UAV community will benefit from designing robust controls using the optimized method utilized in this paper and moreover this will provide sophisticated control to operate in unpredictable environments. It is observed that results obtained for optimized lateral control dynamics using phase lead compensator (PLC) are efficacious than the simple PID feedback gains. However, for optimizing unwanted signals of lateral velocity, yaw rate, and yaw angle modes, PLC were integrated with PID to achieve dynamical stability.
文摘Despite the development of newer oncological treatment,the survival of patients with pancreatic cancer(PC)remains poor.Recent studies have identified exosomes as essential mediators of intercellular communications and play a vital role in tumor initiation,metastasis and chemoresistance.Thus,the utility of liquid biopsies using exosomes in PC management can be used for early detection,diagnosis,monitoring as well as drug delivery vehicles for cancer therapy.This review summarizes the function,and clinical applications of exosomes in cancers as minimally invasive liquid biomarker in diagnostic,prognostic and therapeutic roles.
文摘Development of asymptotic magnitude Bode plots for integer-order transfer functions is a well-established topic in the control theory.However,construction of such plots for the fractional-order transfer functions has not received much attention in the existing literature.In the present paper,we investigate in this direction and derive the procedures for sketching asymptotic magnitude Bode plots for some of the popular fractional-order controllers such as PI^α,[PI]^α,PD^β,[PD]^β,and PI^αD^β.In addition,we deduce these plots for general fractional commensurate-order transfer functions as well.As applications of this work,we illustrate 1)the analysis of the designed fractional-control loop and 2)the identification of fractional-order transfer function from a given plot.
文摘Cancer is a disease that is rapidly expanding in prevalence all over the world.Cancer cells canmetastasize,or spread,across the body and impact several different cell types.Additionally,the incidence rates of several subtypes of cancer have been on the rise in India.The countermeasures for the cancer disease can be taken by determining the specific expansion rate of each type.To rank the various forms of cancer’s rate of progression,we used some of the available data.Numerous studies are available in the literature which show the growth rate of cancer by different techniques.The accuracy of the scheme in determining the highest growth rate may vary due to the variation in the dependent factors.Within the context of this research,the Fuzzy triangular technique for order preference by similarity to ideal solution(TOPSIS),is utilized to rank the various categorizations of cancer with the help of four groups of medical professionals acting in the capacity of decision-makers.The number of decision-makers may variate according to the required accuracy of results.The findings of the three-dimensional Fuzzy TOPSIS analysis categorize each variety of cancer according to the rate at which it spreads over time.Numerical results along with visual representation are presented to examine the efficiency of our proposed work.
基金funded by Princess Nourah bint Abdulrahman University Researchers Supporting Project number(PNURSP2025R 500)Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabia.
文摘In designing a modern home with a focus on the comfort of residents and energy usage optimization simultaneously,the rise of the Internet of Things and its incorporation with sensor technology plays a vital role these days.The first and foremost task is to predict the energy consumption based on the available data.This study investigates the integration of artificial neural networks in smart home technology to improve energy usage prediction and efficiency,without compromising the comfort of occupants.A dynamic model based on an artificial neural network model is designed in this study which artificially controls light,heating process,and cooling to cut down energy wastage.Energy consumption data of 114 single-family apartments was collected between 2014 and 2016.Energy consumption is predicted by the current model with an accuracy of up to 99.9%for energy usage patterns,which helps to optimize resource management in real time.A robust modeling approach i.e.multi-layer perceptron networks was implemented along with energy usage data.Seventy percent of the data is used for training the neural networks,and the rest is used for testing and validation purposes.The current defined model shows a significant improvement in prediction accuracy of energy usage and efficiency when compared to state-of-the-art models.Metrics such as R-values and mean square error are employed to check accuracy.These results show the essential role of artificial intelligence in improving energy management for smart buildings,with potential benefits including significant energy usage and loss management to help improve sustainable living.
