An intercept optimization approach of the exo-atmospheric interceptor is proposed by the middle and terminal flight stages. Firstly, the dynamic models of the exo-atmospheric interceptor in middle and terminal flight ...An intercept optimization approach of the exo-atmospheric interceptor is proposed by the middle and terminal flight stages. Firstly, the dynamic models of the exo-atmospheric interceptor in middle and terminal flight stages are constructed ; and the velocity gain midcourse guidance law and the robust variable structure terminal guidance law are designed. Then the optimization parameters and their constraints affecting the intercept performance are determined. The genetic algorithm （GA） with the advantage of global optimization is used to deal with the intercept optimization problem. The performance index of the optimization is composed of the minimum fuel consumption and the minimum miss distance of the interception. Finally, optimization results of GA and the complex algorithm （CA） are compared. Simulation results show that compared with the traditional opti- mization method, GA can converge to the global optimization better in solving the complex constrained nonlinear combinatorial optimization of the exo-atmospheric interceptor, and reduce the fuel consumption and the miss distance.展开更多
This article proposes a multidisciplinary design and optimization （MDO） strategy for the conceptual design of a multistage ground-based interceptor （GBI） using hybrid optimization algorithm, which associates genet...This article proposes a multidisciplinary design and optimization （MDO） strategy for the conceptual design of a multistage ground-based interceptor （GBI） using hybrid optimization algorithm, which associates genetic algorithm （GA） as a global optimizer with sequential quadratic programming （SQP） as a local optimizer. The interceptor is comprised of a three-stage solid propulsion system for an exoatmospheric boost phase intercept （BPI）. The interceptor＇s duty is to deliver a kinetic kill vehicle （KKV） to the optimal position in space to accomplish the mission of intercept. The modules for propulsion, aerodynamics, mass properties and flight dynamics are integrated to produce a high fidelity model of the entire vehicle. The propulsion module com- prises of solid rocket motor （SRM） grain design, nozzle geometry design and performance prediction analysis. Internal ballistics and performance prediction parameters are calculated by using lumped parameter method. The design objective is to minimize the gross lift off mass （GLOM） of the interceptor under the mission constraints and performance objectives. The proposed design and optimization methodology provide designers with an efficient and powerful approach in computation during designing interceptor systems.展开更多
This contribution deals with capture condition for interceptor missiles steered by aero-lift control system （ALCS） and attitude reaction-jet control system （ARCS）. With the guidance law derived from bounded differ...This contribution deals with capture condition for interceptor missiles steered by aero-lift control system （ALCS） and attitude reaction-jet control system （ARCS）. With the guidance law derived from bounded differential game formulation, existence condition of capture zone is studied for the case that the interceptor has advantage on maneuverability and disadvantage on agility. For the existence of the open capture zone, ARCS can only close after the engagement terminates. Moreover, ARCS also needs to contribute to maneuverability over the minimum required value. More fuel will be required if ARCS increases its contribution to maneuverability. The minimum required fuel occurs at the tangent point of two curves： the curve of critical parameters and a candidate constraint curve, which is also true even for the complex propellant constrain. The validity of these results is also demonstrated by simulations.展开更多
Objective:To evaluate relationship betweenα-cypermethrin residues in Interceptor~? nets by using HPTLC methods and mortality percentage in standard WHO’s method 'cone test' after repeated washings.Methods:In...Objective:To evaluate relationship betweenα-cypermethrin residues in Interceptor~? nets by using HPTLC methods and mortality percentage in standard WHO’s method 'cone test' after repeated washings.Methods:Interceptor~? containingα-cypermethrin was provided by BASF Company.The washing procedure and bioassay tests were carried out according to the WHO-recommended methods.Malaria vector,An.stephensi was exposed to impregnated bed net for three minutes and then mortality measured after 24 hour recovery period.Chemical analysis was carried out in chemical laboratory by using high performance thin layer chromatography method.Results:Result of cone bioassay method showed that washing reduced the efficacy of Interceptor~? bed net from 100%in unwashed nets to 15%at 20 washes.After 20 washes,nets contain(61.2±2.8) mg/m^2 resulting 15%mortality in cone test.Killing activity was reduced when nets were washed.Conclusions:Results will provide an essential clue for monitoring and evaluation of bioefficacy of any long lasting impregnated bed net for quality control.Findings of this study will be useful for WHO.local investigators and people who wish to use pyrethroid-impregnated bed nets for malaria vector control.展开更多
Nowadays,several stern devices are attracting a great deal of attention.The control surface is an effective apparatus for improving the hydrodynamic performance of planing hulls and is considered an important element ...Nowadays,several stern devices are attracting a great deal of attention.The control surface is an effective apparatus for improving the hydrodynamic performance of planing hulls and is considered an important element in the design of planing hulls.Control surfaces produce forces and a pitching moment due to the pressure distribution that they cause,which can be used to change the running state of high-speed marine boats.This work elaborates a new study to evaluate the hydrodynamic performance of a planing boat with a trim tab and an interceptor,and optimizes them by using an optimization algorithm.The trim tab and the interceptor have been used to optimize the running trim and motion control of semi-planing and planing boats at various speeds and sea conditions for many years.In this paper,the usage of trim tab is mathematically verified and experimental equations are utilized to optimize the performance of a planing boat at a specificd trim angle by using an optimization algorithm.The genetic algorithm(GA)is one of the most useful optimizing methods and is used in this study.The planing boat equations were programmed according to Savitsky’s equations and then analyzed in the framework of the GA-based optimization for performance improvement of theplaning hull.The optimal design of trim tab and interceptor for planing boat can be considered a multiobjective problem.The input data of GA include different parameters,such as speed,longitudinal center of gravity,and deadrise angle.We can extract the best range of forecasting the planing boat longitudinal center of gravity,the angle of the trim,and the least drag force at the best trim angle of the boat.展开更多
Lightning interception technology is one of the three core technical systems of regional lightning protection theory.Among them,the omni-directional multi-pulse lightning interceptor(hereinafter referred to as lightni...Lightning interception technology is one of the three core technical systems of regional lightning protection theory.Among them,the omni-directional multi-pulse lightning interceptor(hereinafter referred to as lightning interceptor,the same below)has the ability to attenuate lightning current≥40%and significantly reduce the intensity of the spatial electromagnetic field around the lightning point.In order to explore the attenuation mechanism and effect of lightning interceptor to lightning current,this paper analyzed a lightning stroke process at 16:00 on August 19,2022,and tried to explain the attenuation effect of lightning interceptor to lightning current with the physical parameters of lightning stroke.展开更多
The intercept mode of space-based kinetic energy interceptor(KEI)is an essential problem to be solved in the concept design of KEI and is closely related to the KEI’s detailed designing and practical applications.How...The intercept mode of space-based kinetic energy interceptor(KEI)is an essential problem to be solved in the concept design of KEI and is closely related to the KEI’s detailed designing and practical applications.However,this problem has not yet been investigated systematically and comprehensively.A suitable intercept mode for the KEI is proposed in this research.The intercept mode consists of three basic elements:the specific operation procedure,general scheme for the intercept trajectory,and mathematical model of the intercept mode.Numerical example is provided to demonstrate the feasibility and effectiveness of the intercept mode.The intercept mode proposed in this research is capable of achieving a rapid intercept,and is applicable to the universal space interception.展开更多
Expressway toll station is listed by lightning protection experts as one of the five difficult problems in the field of international lightning protection.So far,the direct lightning protection of the expressway toll ...Expressway toll station is listed by lightning protection experts as one of the five difficult problems in the field of international lightning protection.So far,the direct lightning protection of the expressway toll station is mainly based on the electrical geometry model-rolling ball method.Lightning rod or lightning belt is installed on the high pole lamp of the toll square and the ceiling of the toll island as a flash catching device to intercept lightning.The lightning rod is a section of metal conductor with the tip.From the process of the connection between up leader generated by the lightning rod and down leader of lightning,the lightning rod has the ability to attract the lightning rod,and can prevent lightning strike of the protected objects within a certain range.From the perspective of lightning protection methods and means,lightning protection plays an interception role against lightning discharge,also called interceptor.A large number of practice has proved that the lightning rod plays an important role in protecting the building structure from lightning damage.With the development of electronic information society,the limitations of lightning rod are more and more prominent,resulting in more and more lightning strike accidents.In 2019,China invented a new flash connection device-lightning interceptor that can overcome the limitations of lightning rod and has applied it on expressways,which has achieved remarkable results.In this paper,the physical parameters of lightning receiving process by the lightning interceptor and the lightning rod are compared,and the solution to prevent direct lightning strike at expressway toll station is proposed.展开更多
The guidance and control strategy for endoatmospheric kinetic interceptor controlled by lateral pulse thrusters was detailed.The pulse thruster control system was firstly proposed.The sample-and-hold approach was intr...The guidance and control strategy for endoatmospheric kinetic interceptor controlled by lateral pulse thrusters was detailed.The pulse thruster control system was firstly proposed.The sample-and-hold approach was introduced to design a novel lateral acceleration autopilot on the basis of traditional two-loop topology.Combined with proportional navigation guidance law and the novel autopilot,the overall ballistic trajectory was presented and examined.Simulation results show that the pulse thruster control strategy can greatly improve the control system response speed and the maximal acceleration capability for realizing kinetic kill interception.展开更多
Based on Java RMI framework, a new design is introduced to plug common services into RMI application without modifying the remote interface. This design improves the mechanism of RMI, which is based on dynamic proxy a...Based on Java RMI framework, a new design is introduced to plug common services into RMI application without modifying the remote interface. This design improves the mechanism of RMI, which is based on dynamic proxy and interceptor technology. The implementation of class loader and stub is custom. The design ensures both the integrity of RMI mechanism and the plug-ins of some common services that are based on component. The design improves the modularization of application and decreases the coupling degree among different modules; by this means these middle-ware's modules gain more scalability and flexibility.展开更多
To find a better way to estimate the lift force induced by an interceptor on a high-speed mono-hull ship,a series of high-speed mono-hull ship models are designed and investigated under different conditions.Different ...To find a better way to estimate the lift force induced by an interceptor on a high-speed mono-hull ship,a series of high-speed mono-hull ship models are designed and investigated under different conditions.Different lift forces are obtained by numerical calculations and validated by a model test in a towing tank.The factors that influence the force are the interceptor height,velocity,draft,and deadrise angle.The relationship between each factor and the induced lift force is investigated and obtained.We found that the induced lift mainly depends on the interceptor height and advancing velocity,and is proportional to the square of the interceptor height and velocity.The results also showed that the effects of the draft and deadrise angle are relatively less important,and the relationship between the induced lift and these two factors is generally linear.Based on the results,a formula including the combined effect of all factors used to estimate the lift force induced by the interceptor is developed based on systematic analysis.The proposed formula could be used to estimate the lift force induced by interceptors,especially under high-speed condition.展开更多
A new terminal guidance law is proposed based on a solid propellant pulse engine and an improved proportional navigation method to address the terminal guidance issue for kinetic interceptors.On this basis,the start-s...A new terminal guidance law is proposed based on a solid propellant pulse engine and an improved proportional navigation method to address the terminal guidance issue for kinetic interceptors.On this basis,the start-stop curve of the pulse motor during the terminal guidance process is designed,along with its start-up logic.The effectiveness of the proposed guidance strategy is verified through simulation.展开更多
The capture probability of interceptors has been deeply studied.Firstly,the definition of capture probability is analyzed.It is transformed into calculating the probability that the relative position vector between th...The capture probability of interceptors has been deeply studied.Firstly,the definition of capture probability is analyzed.It is transformed into calculating the probability that the relative position vector between the target and the interceptor locates in a certain cone.The relative position vector and associated covariance matrix are projected in line-of-sight coordinates,and the 3-dimensional integral of a probability function in a cone is calculated to obtain the capture probability.The integral equation is a complicated expression of probability,and it is simplified to an explicit approximate expression according to some assumptions based on the characteristics of the engineering problems.The approximation precision is analyzed by comparative simulation difference,which indicates that approximate assumptions are reasonable.Utilizing the explicit expression,the characteristics of capture probability are analyzed respectively with the factors,such as the distance between the interceptor and the target,the precision of relative position vector,the maximum capture distance and the maximum field angle of interceptor seeker.展开更多
Nowadays, the use of interceptor by both partial and total dynamic lift crafts is quite common. In this article, a lot of evidence is given regarding the effectiveness of interceptor. The interceptor, when placed at t...Nowadays, the use of interceptor by both partial and total dynamic lift crafts is quite common. In this article, a lot of evidence is given regarding the effectiveness of interceptor. The interceptor, when placed at the stern region, changes the pressure distribution around the craft. Its presence affects drag force, lifting force and the position of pressure＇s center leading to a new trim. This study focuses on hydrodynamic effects of interceptors on a 2-D fiat plate based on both computational fluid dynamic （CFD） and experimental approaches. The Reynolds average Navier-Stokes （RANS） equations are used to model the flow around a fixed flat plate with an interceptor at different heights and attack angles. Based on finite volume method and SIMPLE algorithm which uses static structures, this model can be analyzed and the RANS results can be compared with the experimental data obtained in the current channel of the laboratory of waves and current of COPPE/UFRJ （LOC in Portuguese acronym）. According to the results, the increase of pressure at the end of the flat plate was proportional to the interceptor height. In addition, the existence of interceptors can significantly increase the lift force coefficient at high angles of attack also proportional to the interceptor height. The presence of interceptor at the end of the fiat plate increased both the lift coefficient and the drag coefficient but hydrodynamic drag did not grow as fast as the lift coefficient did. The lift coefficient increased much more. Furthermore, the results showed that the interceptor effectiveness is proportional to the boundary layer thickness at the end of the fiat plate. As the interceptor was inside the boundary layer alterations of flow speed led to changes in boundary layer thickness, directly affecting interceptor＇s efficiency. Optimum choice of interceptor height had a great effect on its efficiency, and in choosing it the flow speed and length of the boat must be taken into consideration.展开更多
Background The increasing reports of resistance to pyrethroid insecticides associated with reduced efficacy of pyrethroid-only interventions highlight the urgency of introducing new non-pyrethroid-only control tools.H...Background The increasing reports of resistance to pyrethroid insecticides associated with reduced efficacy of pyrethroid-only interventions highlight the urgency of introducing new non-pyrethroid-only control tools.Here,we investigated the performance of piperonyl-butoxide(PBO)-pyrethroid[Permanet 3.0(P3.0)]and dual active ingredients(AI)nets[Interceptor G2(IG2):containing pyrethroids and chlorfenapyr and Royal Guard(RG):containing pyrethroids and pyriproxyfen]compared to pyrethroid-only net Royal Sentry(RS)against pyrethroid-resistant malaria vectors in Cameroon.Methods The efficacy of these tools was firstly evaluated onAnopheles gambiae s.l.andAnopheles funestus s.l.from Gounougou,Mibellon,Mangoum,Nkolondom,and Elende using cone/tunnel assays.In addition,experimental hut trials(EHT)were performed to evaluate the performance of unwashed and 20 times washed nets in semi-field conditions.Furthermore,pyrethroid-resistant markers were genotyped in dead vs alive,blood-fed vs unfed mosquitoes after exposure to the nets to evaluate the impact of these markers on net performance.The XLSTAT software was used to calculate the various entomological outcomes and the Chi-square test was used to compare the efficacy of various nets.The odds ratio and Fisher exact test were then used to establish the statistical significance of any association between insecticide resistance markers and bed net efficacy.Results Interceptor G2 was the most effective net against wild pyrethroid-resistantAn.funestus followed by Permanet 3.0.In EHT,this net induced up to 87.8%mortality[95%confidence interval(CI):83.5-92.1%)and 55.6%(95%CI:48.5-62.7%)after 20 washes whilst unwashed pyrethroid-only net(Royal Sentry)killed just 18.2%(95%CI:13.4-22.9%)of host-seekingAn.funestus.The unwashed Permanet 3.0 killed up to 53.8%(95%CI:44.3-63.4%)of field-resistant mosquitoes and 47.2%(95%CI:37.7-56.7%)when washed 20 times,and the Royal Guard 13.2%(95%CI:9.0-17.3%)for unwashed net and 8.5%(95%CI:5.7-11.4%)for the 20 washed net.Interceptor G2,Permanet 3.0,and Royal Guard provided better personal protection(blood-feeding inhibition 66.2%,77.8%,and 92.8%,respectively)compared to pyrethroid-only net Royal Sentry(8.4%).Interestingly,a negative association was found betweenkdrw and the chlorfenapyr-based net Interceptor G2(χ^(2)=138;P<0.0001)with homozygote-resistant mosquitoes predominantly found in the dead ones.Conclusions The high mortality recorded with Interceptor G2 against pyrethroid-resistant malaria vectors in this study provides first semi-field evidence of high efficacy against these major malaria vectors in Cameroon encouraging the implementation of this novel net for malaria control in the country.However,the performance of this net should be established in other locations and on other major malaria vectors before implementation at a large scale.展开更多
文摘An intercept optimization approach of the exo-atmospheric interceptor is proposed by the middle and terminal flight stages. Firstly, the dynamic models of the exo-atmospheric interceptor in middle and terminal flight stages are constructed ; and the velocity gain midcourse guidance law and the robust variable structure terminal guidance law are designed. Then the optimization parameters and their constraints affecting the intercept performance are determined. The genetic algorithm （GA） with the advantage of global optimization is used to deal with the intercept optimization problem. The performance index of the optimization is composed of the minimum fuel consumption and the minimum miss distance of the interception. Finally, optimization results of GA and the complex algorithm （CA） are compared. Simulation results show that compared with the traditional opti- mization method, GA can converge to the global optimization better in solving the complex constrained nonlinear combinatorial optimization of the exo-atmospheric interceptor, and reduce the fuel consumption and the miss distance.
文摘This article proposes a multidisciplinary design and optimization （MDO） strategy for the conceptual design of a multistage ground-based interceptor （GBI） using hybrid optimization algorithm, which associates genetic algorithm （GA） as a global optimizer with sequential quadratic programming （SQP） as a local optimizer. The interceptor is comprised of a three-stage solid propulsion system for an exoatmospheric boost phase intercept （BPI）. The interceptor＇s duty is to deliver a kinetic kill vehicle （KKV） to the optimal position in space to accomplish the mission of intercept. The modules for propulsion, aerodynamics, mass properties and flight dynamics are integrated to produce a high fidelity model of the entire vehicle. The propulsion module com- prises of solid rocket motor （SRM） grain design, nozzle geometry design and performance prediction analysis. Internal ballistics and performance prediction parameters are calculated by using lumped parameter method. The design objective is to minimize the gross lift off mass （GLOM） of the interceptor under the mission constraints and performance objectives. The proposed design and optimization methodology provide designers with an efficient and powerful approach in computation during designing interceptor systems.
文摘This contribution deals with capture condition for interceptor missiles steered by aero-lift control system （ALCS） and attitude reaction-jet control system （ARCS）. With the guidance law derived from bounded differential game formulation, existence condition of capture zone is studied for the case that the interceptor has advantage on maneuverability and disadvantage on agility. For the existence of the open capture zone, ARCS can only close after the engagement terminates. Moreover, ARCS also needs to contribute to maneuverability over the minimum required value. More fuel will be required if ARCS increases its contribution to maneuverability. The minimum required fuel occurs at the tangent point of two curves： the curve of critical parameters and a candidate constraint curve, which is also true even for the complex propellant constrain. The validity of these results is also demonstrated by simulations.
基金financially supported by the Tehran University of Medical Sciences
文摘Objective:To evaluate relationship betweenα-cypermethrin residues in Interceptor~? nets by using HPTLC methods and mortality percentage in standard WHO’s method 'cone test' after repeated washings.Methods:Interceptor~? containingα-cypermethrin was provided by BASF Company.The washing procedure and bioassay tests were carried out according to the WHO-recommended methods.Malaria vector,An.stephensi was exposed to impregnated bed net for three minutes and then mortality measured after 24 hour recovery period.Chemical analysis was carried out in chemical laboratory by using high performance thin layer chromatography method.Results:Result of cone bioassay method showed that washing reduced the efficacy of Interceptor~? bed net from 100%in unwashed nets to 15%at 20 washes.After 20 washes,nets contain(61.2±2.8) mg/m^2 resulting 15%mortality in cone test.Killing activity was reduced when nets were washed.Conclusions:Results will provide an essential clue for monitoring and evaluation of bioefficacy of any long lasting impregnated bed net for quality control.Findings of this study will be useful for WHO.local investigators and people who wish to use pyrethroid-impregnated bed nets for malaria vector control.
文摘Nowadays,several stern devices are attracting a great deal of attention.The control surface is an effective apparatus for improving the hydrodynamic performance of planing hulls and is considered an important element in the design of planing hulls.Control surfaces produce forces and a pitching moment due to the pressure distribution that they cause,which can be used to change the running state of high-speed marine boats.This work elaborates a new study to evaluate the hydrodynamic performance of a planing boat with a trim tab and an interceptor,and optimizes them by using an optimization algorithm.The trim tab and the interceptor have been used to optimize the running trim and motion control of semi-planing and planing boats at various speeds and sea conditions for many years.In this paper,the usage of trim tab is mathematically verified and experimental equations are utilized to optimize the performance of a planing boat at a specificd trim angle by using an optimization algorithm.The genetic algorithm(GA)is one of the most useful optimizing methods and is used in this study.The planing boat equations were programmed according to Savitsky’s equations and then analyzed in the framework of the GA-based optimization for performance improvement of theplaning hull.The optimal design of trim tab and interceptor for planing boat can be considered a multiobjective problem.The input data of GA include different parameters,such as speed,longitudinal center of gravity,and deadrise angle.We can extract the best range of forecasting the planing boat longitudinal center of gravity,the angle of the trim,and the least drag force at the best trim angle of the boat.
基金Supported by Technology Research and Development Project of Strong Electro-magnetic Pulse Protection(Lightning)of Sea Wind Field in Guangdong Yuedi-an Zhuhai Biqing Bay.
文摘Lightning interception technology is one of the three core technical systems of regional lightning protection theory.Among them,the omni-directional multi-pulse lightning interceptor(hereinafter referred to as lightning interceptor,the same below)has the ability to attenuate lightning current≥40%and significantly reduce the intensity of the spatial electromagnetic field around the lightning point.In order to explore the attenuation mechanism and effect of lightning interceptor to lightning current,this paper analyzed a lightning stroke process at 16:00 on August 19,2022,and tried to explain the attenuation effect of lightning interceptor to lightning current with the physical parameters of lightning stroke.
基金the National Natural Science Foundation of China(No.11502300)the Aerospace Science Foundation of China(No.20165196018)
文摘The intercept mode of space-based kinetic energy interceptor(KEI)is an essential problem to be solved in the concept design of KEI and is closely related to the KEI’s detailed designing and practical applications.However,this problem has not yet been investigated systematically and comprehensively.A suitable intercept mode for the KEI is proposed in this research.The intercept mode consists of three basic elements:the specific operation procedure,general scheme for the intercept trajectory,and mathematical model of the intercept mode.Numerical example is provided to demonstrate the feasibility and effectiveness of the intercept mode.The intercept mode proposed in this research is capable of achieving a rapid intercept,and is applicable to the universal space interception.
基金Supported by Regional Lightning Protection Engineering Technology Research and Development Project(PhaseⅡ)in Guangdong Yuedian Dianbai Wind Farm(SFC/DBW-ZX-FW-22-006)。
文摘Expressway toll station is listed by lightning protection experts as one of the five difficult problems in the field of international lightning protection.So far,the direct lightning protection of the expressway toll station is mainly based on the electrical geometry model-rolling ball method.Lightning rod or lightning belt is installed on the high pole lamp of the toll square and the ceiling of the toll island as a flash catching device to intercept lightning.The lightning rod is a section of metal conductor with the tip.From the process of the connection between up leader generated by the lightning rod and down leader of lightning,the lightning rod has the ability to attract the lightning rod,and can prevent lightning strike of the protected objects within a certain range.From the perspective of lightning protection methods and means,lightning protection plays an interception role against lightning discharge,also called interceptor.A large number of practice has proved that the lightning rod plays an important role in protecting the building structure from lightning damage.With the development of electronic information society,the limitations of lightning rod are more and more prominent,resulting in more and more lightning strike accidents.In 2019,China invented a new flash connection device-lightning interceptor that can overcome the limitations of lightning rod and has applied it on expressways,which has achieved remarkable results.In this paper,the physical parameters of lightning receiving process by the lightning interceptor and the lightning rod are compared,and the solution to prevent direct lightning strike at expressway toll station is proposed.
基金Supported by the National Natural Science Foundation of China(61172182)
文摘The guidance and control strategy for endoatmospheric kinetic interceptor controlled by lateral pulse thrusters was detailed.The pulse thruster control system was firstly proposed.The sample-and-hold approach was introduced to design a novel lateral acceleration autopilot on the basis of traditional two-loop topology.Combined with proportional navigation guidance law and the novel autopilot,the overall ballistic trajectory was presented and examined.Simulation results show that the pulse thruster control strategy can greatly improve the control system response speed and the maximal acceleration capability for realizing kinetic kill interception.
基金by the Ministerial Level Advanced Research Foundation(413040402)
文摘Based on Java RMI framework, a new design is introduced to plug common services into RMI application without modifying the remote interface. This design improves the mechanism of RMI, which is based on dynamic proxy and interceptor technology. The implementation of class loader and stub is custom. The design ensures both the integrity of RMI mechanism and the plug-ins of some common services that are based on component. The design improves the modularization of application and decreases the coupling degree among different modules; by this means these middle-ware's modules gain more scalability and flexibility.
基金financially supported by the National Key Research and Development Program of China(Grant No.2021YFC2800700)the National Natural Science Foundation of China(Grant Nos.52171330,52101379,52101380,51679053)+2 种基金the Project of Research and Development Plan in Key Areas of Guangdong Province(Grant No.2020B1111010002)the Foundation of Key Laboratory of Marine Environmental Survey Technology and Application,Ministry of Natural Resources(Grant No.MESTA-2021-B010)the Natural Science Foundation of Guangdong Province,China(Grant No.2021A1515012134)。
文摘To find a better way to estimate the lift force induced by an interceptor on a high-speed mono-hull ship,a series of high-speed mono-hull ship models are designed and investigated under different conditions.Different lift forces are obtained by numerical calculations and validated by a model test in a towing tank.The factors that influence the force are the interceptor height,velocity,draft,and deadrise angle.The relationship between each factor and the induced lift force is investigated and obtained.We found that the induced lift mainly depends on the interceptor height and advancing velocity,and is proportional to the square of the interceptor height and velocity.The results also showed that the effects of the draft and deadrise angle are relatively less important,and the relationship between the induced lift and these two factors is generally linear.Based on the results,a formula including the combined effect of all factors used to estimate the lift force induced by the interceptor is developed based on systematic analysis.The proposed formula could be used to estimate the lift force induced by interceptors,especially under high-speed condition.
基金The National Natural Science Foundation of China(Project No.52102436)The Natural Science Foundation of Shanghai(Project No.23ZR1462700)+3 种基金The National Key Laboratory Open Fund for Strength and Structural Integrity(Project No.ASSIKFJJ202304006)The Shanghai Aerospace Science and Technology Innovation Fund(Project No.SAST2022-031)The National Key Laboratory of Space Intelligent Control(Project No.2023-JCJQ-LB-006-14)The Shanghai Key Laboratory of Spacecraft Mechanism(Project No.YY-F805202210025)。
文摘A new terminal guidance law is proposed based on a solid propellant pulse engine and an improved proportional navigation method to address the terminal guidance issue for kinetic interceptors.On this basis,the start-stop curve of the pulse motor during the terminal guidance process is designed,along with its start-up logic.The effectiveness of the proposed guidance strategy is verified through simulation.
文摘The capture probability of interceptors has been deeply studied.Firstly,the definition of capture probability is analyzed.It is transformed into calculating the probability that the relative position vector between the target and the interceptor locates in a certain cone.The relative position vector and associated covariance matrix are projected in line-of-sight coordinates,and the 3-dimensional integral of a probability function in a cone is calculated to obtain the capture probability.The integral equation is a complicated expression of probability,and it is simplified to an explicit approximate expression according to some assumptions based on the characteristics of the engineering problems.The approximation precision is analyzed by comparative simulation difference,which indicates that approximate assumptions are reasonable.Utilizing the explicit expression,the characteristics of capture probability are analyzed respectively with the factors,such as the distance between the interceptor and the target,the precision of relative position vector,the maximum capture distance and the maximum field angle of interceptor seeker.
文摘Nowadays, the use of interceptor by both partial and total dynamic lift crafts is quite common. In this article, a lot of evidence is given regarding the effectiveness of interceptor. The interceptor, when placed at the stern region, changes the pressure distribution around the craft. Its presence affects drag force, lifting force and the position of pressure＇s center leading to a new trim. This study focuses on hydrodynamic effects of interceptors on a 2-D fiat plate based on both computational fluid dynamic （CFD） and experimental approaches. The Reynolds average Navier-Stokes （RANS） equations are used to model the flow around a fixed flat plate with an interceptor at different heights and attack angles. Based on finite volume method and SIMPLE algorithm which uses static structures, this model can be analyzed and the RANS results can be compared with the experimental data obtained in the current channel of the laboratory of waves and current of COPPE/UFRJ （LOC in Portuguese acronym）. According to the results, the increase of pressure at the end of the flat plate was proportional to the interceptor height. In addition, the existence of interceptors can significantly increase the lift force coefficient at high angles of attack also proportional to the interceptor height. The presence of interceptor at the end of the fiat plate increased both the lift coefficient and the drag coefficient but hydrodynamic drag did not grow as fast as the lift coefficient did. The lift coefficient increased much more. Furthermore, the results showed that the interceptor effectiveness is proportional to the boundary layer thickness at the end of the fiat plate. As the interceptor was inside the boundary layer alterations of flow speed led to changes in boundary layer thickness, directly affecting interceptor＇s efficiency. Optimum choice of interceptor height had a great effect on its efficiency, and in choosing it the flow speed and length of the boat must be taken into consideration.
基金This work was supported by the PIIVEC operational research project(PV/OP2-03/TW to MT under the MRC grant MR/PO27873/1),the Renewal Wellcome Trust Senior Research Fellowship in Biomedical Sciences(217188/Z/19/Z),and the BMGF Grant(INV-006003)awarded to CSW.
文摘Background The increasing reports of resistance to pyrethroid insecticides associated with reduced efficacy of pyrethroid-only interventions highlight the urgency of introducing new non-pyrethroid-only control tools.Here,we investigated the performance of piperonyl-butoxide(PBO)-pyrethroid[Permanet 3.0(P3.0)]and dual active ingredients(AI)nets[Interceptor G2(IG2):containing pyrethroids and chlorfenapyr and Royal Guard(RG):containing pyrethroids and pyriproxyfen]compared to pyrethroid-only net Royal Sentry(RS)against pyrethroid-resistant malaria vectors in Cameroon.Methods The efficacy of these tools was firstly evaluated onAnopheles gambiae s.l.andAnopheles funestus s.l.from Gounougou,Mibellon,Mangoum,Nkolondom,and Elende using cone/tunnel assays.In addition,experimental hut trials(EHT)were performed to evaluate the performance of unwashed and 20 times washed nets in semi-field conditions.Furthermore,pyrethroid-resistant markers were genotyped in dead vs alive,blood-fed vs unfed mosquitoes after exposure to the nets to evaluate the impact of these markers on net performance.The XLSTAT software was used to calculate the various entomological outcomes and the Chi-square test was used to compare the efficacy of various nets.The odds ratio and Fisher exact test were then used to establish the statistical significance of any association between insecticide resistance markers and bed net efficacy.Results Interceptor G2 was the most effective net against wild pyrethroid-resistantAn.funestus followed by Permanet 3.0.In EHT,this net induced up to 87.8%mortality[95%confidence interval(CI):83.5-92.1%)and 55.6%(95%CI:48.5-62.7%)after 20 washes whilst unwashed pyrethroid-only net(Royal Sentry)killed just 18.2%(95%CI:13.4-22.9%)of host-seekingAn.funestus.The unwashed Permanet 3.0 killed up to 53.8%(95%CI:44.3-63.4%)of field-resistant mosquitoes and 47.2%(95%CI:37.7-56.7%)when washed 20 times,and the Royal Guard 13.2%(95%CI:9.0-17.3%)for unwashed net and 8.5%(95%CI:5.7-11.4%)for the 20 washed net.Interceptor G2,Permanet 3.0,and Royal Guard provided better personal protection(blood-feeding inhibition 66.2%,77.8%,and 92.8%,respectively)compared to pyrethroid-only net Royal Sentry(8.4%).Interestingly,a negative association was found betweenkdrw and the chlorfenapyr-based net Interceptor G2(χ^(2)=138;P<0.0001)with homozygote-resistant mosquitoes predominantly found in the dead ones.Conclusions The high mortality recorded with Interceptor G2 against pyrethroid-resistant malaria vectors in this study provides first semi-field evidence of high efficacy against these major malaria vectors in Cameroon encouraging the implementation of this novel net for malaria control in the country.However,the performance of this net should be established in other locations and on other major malaria vectors before implementation at a large scale.
