With direct expression of individual application domain patterns and ideas,domain-specific modeling language（DSML） is more and more frequently used to build models instead of using a combination of one or more gener...With direct expression of individual application domain patterns and ideas,domain-specific modeling language（DSML） is more and more frequently used to build models instead of using a combination of one or more general constructs.Based on the profile mechanism of unified modeling language（UML） 2.2,a kind of DSML is presented to model simulation testing systems of avionic software（STSAS）.To define the syntax,semantics and notions of the DSML,the domain model of the STSAS from which we generalize the domain concepts and relationships among these concepts is given,and then,the domain model is mapped into a UML meta-model,named UML-STSAS profile.Assuming a flight control system（FCS） as system under test（SUT）,we design the relevant STSAS.The results indicate that extending UML to the simulation testing domain can effectively and precisely model STSAS.展开更多
COVID-19 has become one of the critical health issues globally,which surfaced first in latter part of the year 2019.It is the topmost concern for many nations’governments as the contagious virus started mushrooming o...COVID-19 has become one of the critical health issues globally,which surfaced first in latter part of the year 2019.It is the topmost concern for many nations’governments as the contagious virus started mushrooming over adjacent regions of infected areas.In 1980,a vaccine called Bacillus Calmette-Guérin(BCG)was introduced for preventing tuberculosis and lung cancer.Countries that have made the BCG vaccine mandatory have witnessed a lesser COVID-19 fatality rate than the countries that have not made it compulsory.This paper’s initial research shows that the countries with a longtermcompulsory BCGvaccination system are less affected by COVID-19 than those without a BCG vaccination system.This paper discusses analytical data patterns for medical applications regarding COVID-19 impact on countries with mandatory BCG status on fatality rates.The paper has tackled numerous analytical challenges to realize the full potential of heterogeneous data.An analogy is drawn to demonstrate how other factors can affect fatality and infection rates other than BCG vaccination only,such as age groups affected,other diseases,and stringency index.The data of Spain,Portugal,and Germany have been taken for a case study of BCG impact analysis.展开更多
The aim of this paper is to present graphically the behaviour of a simulation model to the varying parameters and to establish the suitability of this representation as a valid tool for the analysis of the same parame...The aim of this paper is to present graphically the behaviour of a simulation model to the varying parameters and to establish the suitability of this representation as a valid tool for the analysis of the same parameters. In this paper, we define parameter combinatorial diagram as the joint graphical representation of all box plots related to the adjustment between real and simulated data, by setting and/or changing the parameters of the simulation model. To do this, we start with a box plot representing the values of an objective adjustment function, achieving these results when varying all the parameters of the simulation model, Then we draw the box plot when setting all the parameters of the model, for example, using the median or average. Later, we get all the box plots when carrying out simulations combining fixed or variable values of the model parameters. Finally, all box plots obtained are represented neatly in a single graph. It is intended that the new parameter combinatorial diagram is used to examine and analyze simulation models useful in practice. This paper presents combinatorial diagrams of different examples of application as in the case of hydrologic models of one, two, three, and five parameters.展开更多
Fault detection of the photovoltaic(PV)grid is necessary to detect serious output power reduction to avoid PV modules’damage.To identify the fault of the PV arrays,there is a necessity to implement an automatic syste...Fault detection of the photovoltaic(PV)grid is necessary to detect serious output power reduction to avoid PV modules’damage.To identify the fault of the PV arrays,there is a necessity to implement an automatic system.In this IoT and LabVIEW-based automatic fault detection of 3×3 solar array,a PV system is proposed to control and monitor Internet connectivity remotely.Hardware component to automatically reconfigure the solar PV array from the series-parallel(SP)to the complete cross-linked array underneath partial shading conditions(PSC)is centered on the Atmega328 system to achieve maximum power.In the LabVIEW environment,an automated monitoring system is developed.The automatic monitoring system assesses the voltage drop losses present in the DC side of the PV generator and generates a decimal weighted value depending on the defective solar panels and transmits this value to the remote station through an RF modem,and provides an indicator of the faulty solar panel over the built-in Interface LabVIEW.The managing of this GUI indicator helps the monitoring system to generate a panel alert for damaged panels in the PV system.Node MCU in the receiver section enables transmission of the fault status of PV arrays via Internet connectivity.The IoT-based Blynk app is employed for visualizing the fault status of the 3×3 PV array.The dashboard of Blynk visualizes every array with the status.展开更多
In this communication we start both from a trirectangular trihedral defined by the three coordinate planes and a fourth plane, called the chart or projection, which contains the vertex of the trihedral above. Later we...In this communication we start both from a trirectangular trihedral defined by the three coordinate planes and a fourth plane, called the chart or projection, which contains the vertex of the trihedral above. Later we define the main related views or trihedral views as those produced by the tilt of the three coordinate planes to the outside of their trihedral on the chart plane. For each projection plane there are some unique main related views, regardless of the projection direction. In turn, from the trihedral views we can obtain the axonometric perspective from which they come. These properties can simplify some graphic constructions of the axonometric system, for example, determine the projections of the axes from the main related views or determine the axonometric scales from the axes. It is considered that this new definition of related views allows a simplification as to the understanding of the representation systems and it is intended to be suitable for teaching purposes and programming.展开更多
This study investigates the development of novel montmorillonite/castor oil blends to formulate sustainable lubricating greases to promote the replacement of petrochemicals industry-derived materials by substances obt...This study investigates the development of novel montmorillonite/castor oil blends to formulate sustainable lubricating greases to promote the replacement of petrochemicals industry-derived materials by substances obtained from renewable sources.Specifically,the effect of the thickener concentration on the rheological,chemical,thermal,tribological properties,and atomic force microscopy(AFM)microstructure of these systems were studied.The results showed that the C20A nanoclay content could be used to modulate the viscosity values,the linear viscoelastic functions,and tribological properties of these montmorillonite dispersions.In general,these gel-like dispersions exhibited remarkable lubricant properties;the samples showed values of the friction coefficient and wear scars similar or lower than those obtained with model bentonite grease.展开更多
This paper proposes an individual fitness method genetic algorithm(IFM-GA)for carbon fiber-reinforced plastic(CFRP).The strength of CFRP depends on the carbon fiber allocation and orientation.Waste carbon fiber is gen...This paper proposes an individual fitness method genetic algorithm(IFM-GA)for carbon fiber-reinforced plastic(CFRP).The strength of CFRP depends on the carbon fiber allocation and orientation.Waste carbon fiber is generated if this design is inappropriate.Consequently,CFRPs are less cost-effective.It is necessary to optimize the allocation and orientation as design variables to solve this problem.The problem involves combinatorial optimization.The genetic algorithm(GA)is suitable for combinatorial optimization.However,it is difficult to obtain an optimal solution using the GA owing to the large number of combinations.Hence,the IFM-GA is developed in this study.It is a GA-based method with a different fitness calculation.The GA calculates the fitness of each design,whereas the IFM-GA calculates the fitness of each design element.As a result,the IFM-GA yields a higher-stiffness design than the GA.To conclude,the IFM-GA can enable optimum fiber allocation and orientation,whereas the GA cannot.展开更多
The concept of employing thermoelectric generators(TEGs)to recover energy from waste heat has gained popularity,with applications that range from milliwatt to kilowatt levels of output power.In this study,a hybrid pho...The concept of employing thermoelectric generators(TEGs)to recover energy from waste heat has gained popularity,with applications that range from milliwatt to kilowatt levels of output power.In this study,a hybrid photovoltaic panel and thermoelectric generator(HPVTEG)system consisting of an integrated heat exchanger,a commercial polycrystalline silicon photovoltaic(PV)panel and a commercial bismuth telluride TEG was proposed.Here,TE components can be used to cool PV modules,increasing their output power via the Seebeck effect.The main finding is that the hybrid system has a reduced average temperature of 16.01°C.The average power of the stand-alone PV panel is 28.06 W,but that of the HPVTEG system is 32.76 W,which is an increase of 4.7 W.The conversion efficiency and power of the hybrid system increased by 16.7%and 16.4%,respectively,compared with a stand-alone PV panel.The HPVTEG system achieved an average exergy efficiency of 12.79%compared with 10.98%for a stand-alone PV panel.According to the calculation results,the levelized cost of energy(LCOE)of the stand-alone PV panel can range from 0.06741 to 0.10251 US$/kWh depending on how many days it is in operation,while the LCOE of the HPVTEG system can range from 0.06681 to 0.10160 US$/kWh.展开更多
The outcome of this paper is to suggest an efficient energy-management strategy(EMS)for a direct-current(DC)microgrid(MG).The typical MG is composed of two renewable energy sources[photovoltaic(PV)systems and fuel cel...The outcome of this paper is to suggest an efficient energy-management strategy(EMS)for a direct-current(DC)microgrid(MG).The typical MG is composed of two renewable energy sources[photovoltaic(PV)systems and fuel cells(FCs)]and two energy-storage elements(lithium-ion battery and supercapacitor).An EMS was proposed to ensure optimal bus voltage with a power-sharing arrangement between the load and the sources.As a result,in the suggested DC MG,non-linear flatness control theory was used instead of the traditional proportional-integral control approach.The suggested EMS is intended to supply high power quality to the load under varying load conditions with fluctuating solar irradiation while considering the FC status.To validate and prove the effectiveness of the proposed EMS,a MATLAB®environment was used.In addition,the output power of the PV system was maximized using the particle swarm optimization algorithm as a maximum power point tracking(MPPT)technique to track the MPP of the 3000-W PV system under different irradiance conditions.The results show that the suggested EMS delivers a stable and smooth DC bus voltage with minimum overshoot value(0.1%)and improved ripple content(0.1%).As a result,the performance of the DC MG was enhanced by employing the flatness control theory,which provides higher power quality by stabilizing the bus voltage.展开更多
基金Aeronautical Science Foundation of China (20095551025)
文摘With direct expression of individual application domain patterns and ideas,domain-specific modeling language（DSML） is more and more frequently used to build models instead of using a combination of one or more general constructs.Based on the profile mechanism of unified modeling language（UML） 2.2,a kind of DSML is presented to model simulation testing systems of avionic software（STSAS）.To define the syntax,semantics and notions of the DSML,the domain model of the STSAS from which we generalize the domain concepts and relationships among these concepts is given,and then,the domain model is mapped into a UML meta-model,named UML-STSAS profile.Assuming a flight control system（FCS） as system under test（SUT）,we design the relevant STSAS.The results indicate that extending UML to the simulation testing domain can effectively and precisely model STSAS.
文摘COVID-19 has become one of the critical health issues globally,which surfaced first in latter part of the year 2019.It is the topmost concern for many nations’governments as the contagious virus started mushrooming over adjacent regions of infected areas.In 1980,a vaccine called Bacillus Calmette-Guérin(BCG)was introduced for preventing tuberculosis and lung cancer.Countries that have made the BCG vaccine mandatory have witnessed a lesser COVID-19 fatality rate than the countries that have not made it compulsory.This paper’s initial research shows that the countries with a longtermcompulsory BCGvaccination system are less affected by COVID-19 than those without a BCG vaccination system.This paper discusses analytical data patterns for medical applications regarding COVID-19 impact on countries with mandatory BCG status on fatality rates.The paper has tackled numerous analytical challenges to realize the full potential of heterogeneous data.An analogy is drawn to demonstrate how other factors can affect fatality and infection rates other than BCG vaccination only,such as age groups affected,other diseases,and stringency index.The data of Spain,Portugal,and Germany have been taken for a case study of BCG impact analysis.
文摘The aim of this paper is to present graphically the behaviour of a simulation model to the varying parameters and to establish the suitability of this representation as a valid tool for the analysis of the same parameters. In this paper, we define parameter combinatorial diagram as the joint graphical representation of all box plots related to the adjustment between real and simulated data, by setting and/or changing the parameters of the simulation model. To do this, we start with a box plot representing the values of an objective adjustment function, achieving these results when varying all the parameters of the simulation model, Then we draw the box plot when setting all the parameters of the model, for example, using the median or average. Later, we get all the box plots when carrying out simulations combining fixed or variable values of the model parameters. Finally, all box plots obtained are represented neatly in a single graph. It is intended that the new parameter combinatorial diagram is used to examine and analyze simulation models useful in practice. This paper presents combinatorial diagrams of different examples of application as in the case of hydrologic models of one, two, three, and five parameters.
基金This work was funded and supported by the Taif University Researchers Supporting Project Number(TURSP-2020/147),Taif University,Taif,Saudi Arabia.
文摘Fault detection of the photovoltaic(PV)grid is necessary to detect serious output power reduction to avoid PV modules’damage.To identify the fault of the PV arrays,there is a necessity to implement an automatic system.In this IoT and LabVIEW-based automatic fault detection of 3×3 solar array,a PV system is proposed to control and monitor Internet connectivity remotely.Hardware component to automatically reconfigure the solar PV array from the series-parallel(SP)to the complete cross-linked array underneath partial shading conditions(PSC)is centered on the Atmega328 system to achieve maximum power.In the LabVIEW environment,an automated monitoring system is developed.The automatic monitoring system assesses the voltage drop losses present in the DC side of the PV generator and generates a decimal weighted value depending on the defective solar panels and transmits this value to the remote station through an RF modem,and provides an indicator of the faulty solar panel over the built-in Interface LabVIEW.The managing of this GUI indicator helps the monitoring system to generate a panel alert for damaged panels in the PV system.Node MCU in the receiver section enables transmission of the fault status of PV arrays via Internet connectivity.The IoT-based Blynk app is employed for visualizing the fault status of the 3×3 PV array.The dashboard of Blynk visualizes every array with the status.
文摘In this communication we start both from a trirectangular trihedral defined by the three coordinate planes and a fourth plane, called the chart or projection, which contains the vertex of the trihedral above. Later we define the main related views or trihedral views as those produced by the tilt of the three coordinate planes to the outside of their trihedral on the chart plane. For each projection plane there are some unique main related views, regardless of the projection direction. In turn, from the trihedral views we can obtain the axonometric perspective from which they come. These properties can simplify some graphic constructions of the axonometric system, for example, determine the projections of the axes from the main related views or determine the axonometric scales from the axes. It is considered that this new definition of related views allows a simplification as to the understanding of the representation systems and it is intended to be suitable for teaching purposes and programming.
文摘This study investigates the development of novel montmorillonite/castor oil blends to formulate sustainable lubricating greases to promote the replacement of petrochemicals industry-derived materials by substances obtained from renewable sources.Specifically,the effect of the thickener concentration on the rheological,chemical,thermal,tribological properties,and atomic force microscopy(AFM)microstructure of these systems were studied.The results showed that the C20A nanoclay content could be used to modulate the viscosity values,the linear viscoelastic functions,and tribological properties of these montmorillonite dispersions.In general,these gel-like dispersions exhibited remarkable lubricant properties;the samples showed values of the friction coefficient and wear scars similar or lower than those obtained with model bentonite grease.
文摘This paper proposes an individual fitness method genetic algorithm(IFM-GA)for carbon fiber-reinforced plastic(CFRP).The strength of CFRP depends on the carbon fiber allocation and orientation.Waste carbon fiber is generated if this design is inappropriate.Consequently,CFRPs are less cost-effective.It is necessary to optimize the allocation and orientation as design variables to solve this problem.The problem involves combinatorial optimization.The genetic algorithm(GA)is suitable for combinatorial optimization.However,it is difficult to obtain an optimal solution using the GA owing to the large number of combinations.Hence,the IFM-GA is developed in this study.It is a GA-based method with a different fitness calculation.The GA calculates the fitness of each design,whereas the IFM-GA calculates the fitness of each design element.As a result,the IFM-GA yields a higher-stiffness design than the GA.To conclude,the IFM-GA can enable optimum fiber allocation and orientation,whereas the GA cannot.
基金the Ministry of Science and Higher Education of the Russian Federation(Ural Federal University Program of Development within the Priority-2030 Program)is gratefully acknowledged(grant number FEUZ-2022-0031).
文摘The concept of employing thermoelectric generators(TEGs)to recover energy from waste heat has gained popularity,with applications that range from milliwatt to kilowatt levels of output power.In this study,a hybrid photovoltaic panel and thermoelectric generator(HPVTEG)system consisting of an integrated heat exchanger,a commercial polycrystalline silicon photovoltaic(PV)panel and a commercial bismuth telluride TEG was proposed.Here,TE components can be used to cool PV modules,increasing their output power via the Seebeck effect.The main finding is that the hybrid system has a reduced average temperature of 16.01°C.The average power of the stand-alone PV panel is 28.06 W,but that of the HPVTEG system is 32.76 W,which is an increase of 4.7 W.The conversion efficiency and power of the hybrid system increased by 16.7%and 16.4%,respectively,compared with a stand-alone PV panel.The HPVTEG system achieved an average exergy efficiency of 12.79%compared with 10.98%for a stand-alone PV panel.According to the calculation results,the levelized cost of energy(LCOE)of the stand-alone PV panel can range from 0.06741 to 0.10251 US$/kWh depending on how many days it is in operation,while the LCOE of the HPVTEG system can range from 0.06681 to 0.10160 US$/kWh.
文摘The outcome of this paper is to suggest an efficient energy-management strategy(EMS)for a direct-current(DC)microgrid(MG).The typical MG is composed of two renewable energy sources[photovoltaic(PV)systems and fuel cells(FCs)]and two energy-storage elements(lithium-ion battery and supercapacitor).An EMS was proposed to ensure optimal bus voltage with a power-sharing arrangement between the load and the sources.As a result,in the suggested DC MG,non-linear flatness control theory was used instead of the traditional proportional-integral control approach.The suggested EMS is intended to supply high power quality to the load under varying load conditions with fluctuating solar irradiation while considering the FC status.To validate and prove the effectiveness of the proposed EMS,a MATLAB®environment was used.In addition,the output power of the PV system was maximized using the particle swarm optimization algorithm as a maximum power point tracking(MPPT)technique to track the MPP of the 3000-W PV system under different irradiance conditions.The results show that the suggested EMS delivers a stable and smooth DC bus voltage with minimum overshoot value(0.1%)and improved ripple content(0.1%).As a result,the performance of the DC MG was enhanced by employing the flatness control theory,which provides higher power quality by stabilizing the bus voltage.
