The precise tuning of magnetic nanoparticle size and magnetic domains,thereby shaping magnetic properties.However,the dynamic evolution mechanisms of magnetic domain configurations in relation to electromagnetic(EM)at...The precise tuning of magnetic nanoparticle size and magnetic domains,thereby shaping magnetic properties.However,the dynamic evolution mechanisms of magnetic domain configurations in relation to electromagnetic(EM)attenuation behavior remain poorly understood.To address this gap,a thermodynamically controlled periodic coordination strategy is proposed to achieve precise modulation of magnetic nanoparticle spacing.This approach unveils the evolution of magnetic domain configurations,progressing from individual to coupled and ultimately to crosslinked domain configurations.A unique magnetic coupling phenomenon surpasses the Snoek limit in low-frequency range,which is observed through micromagnetic simulation.The crosslinked magnetic configuration achieves effective low-frequency EM wave absorption at 3.68 GHz,encompassing nearly the entire C-band.This exceptional magnetic interaction significantly enhances radar camouflage and thermal insulation properties.Additionally,a robust gradient metamaterial design extends coverage across the full band(2–40 GHz),effectively mitigating the impact of EM pollution on human health and environment.This comprehensive study elucidates the evolution mechanisms of magnetic domain configurations,addresses gaps in dynamic magnetic modulation,and provides novel insights for the development of high-performance,low-frequency EM wave absorption materials.展开更多
A fast image segmentation algorithm based on salient features model and spatial-frequency domain adaptive kernel is proposed to solve the accurate discriminate objects problem of online visual detection in such scenes...A fast image segmentation algorithm based on salient features model and spatial-frequency domain adaptive kernel is proposed to solve the accurate discriminate objects problem of online visual detection in such scenes of variable sample morphological characteristics,low contrast and complex background texture.Firstly,by analyzing the spectral component distribution and spatial contour feature of the image,a salient feature model is established in spatial-frequency domain.Then,the salient object detection method based on Gaussian band-pass filter and the design criterion of adaptive convolution kernel are proposed to extract the salient contour feature of the target in spatial and frequency domain.Finally,the selection and growth rules of seed points are improved by integrating the gray level and contour features of the target,and the target is segmented by seeded region growing.Experiments have been performed on Berkeley Segmentation Data Set,as well as sample images of online detection,to verify the effectiveness of the algorithm.The experimental results show that the Jaccard Similarity Coefficient of the segmentation is more than 90%,which indicates that the proposed algorithm can availably extract the target feature information,suppress the background texture and resist noise interference.Besides,the Hausdorff Distance of the segmentation is less than 10,which infers that the proposed algorithm obtains a high evaluation on the target contour preservation.The experimental results also show that the proposed algorithm significantly improves the operation efficiency while obtaining comparable segmentation performance over other algorithms.展开更多
To study the domain decomposition algorithms for the equations of elliptic type, the method of optimal boundary control was used to advance a new procedure for domain decomposition algorithms and regularization method...To study the domain decomposition algorithms for the equations of elliptic type, the method of optimal boundary control was used to advance a new procedure for domain decomposition algorithms and regularization method to deal with the ill posedness of the control problem. The determination of the value of the solution of the partial differential equation on the interface——the key of the domain decomposition algorithms——was transformed into a boundary control problem and the ill posedness of the control problem was overcome by regularization. The convergence of the regularizing control solution was proven and the equations which characterize the optimal control were given therefore the value of the unknown solution on the interface of the domain would be obtained by solving a series of coupling equations. Using the boundary control method the domain decomposion algorithm can be carried out.展开更多
In order to understand the community capacity for sustainable community-based dengue prevention and control,this paper proposes the approach of a previous study about meaning and domains of dengue prevention and contr...In order to understand the community capacity for sustainable community-based dengue prevention and control,this paper proposes the approach of a previous study about meaning and domains of dengue prevention and control,an assessment tool and a community capacity building model for sustainable community-based dengue prevention and control in the Southern Thailand. A study of dengue community capacity domains was conducted by utilizing a qualitative method, whereby ten initial community domains were identified by means of a literature review,in-depth interviews of sixty community leaders,and eight focus group discussions with sixty non-leaders in four sub-districts of southern Thailand.In the final study,there were 14 identifiable domains in leaders group and 11 domains in non-leaders.The resulting dengue community capacity-assessment tool(DCCAT) consisted of two parts:one for leaders(DCCAT-L) and the other for non-leaders (DCCAT-NL).DCCAT-L was composed of 115 items within 14 domains and 83 items within 11 domains for the DCCAT-NL.The key domains of leaders and non-leaders had a partial overlap of domains such as critical situation management,personal leadership,health care provider capacity,needs assessment,senses of community,leader group networking,communication of dengue information,community leadership,religious capacity,leader group and community networking,resource mobilization,dengue working group,community participation,and continuing activities.The application of the new tool consisted of five steps:1) community preparation,2) assessment,3) a community hearing meeting,4) interventions,and 5) conclusion and improvement step.All stakeholders in the community should use the new tool based on a clear understanding of the measurement objectives,the desired outcomes,resources available and characteristics of their community.If communities need to develop and build dengue community capacity,then the designed pre-post intervention assessments or serial assessments are essential.展开更多
This paper proposes a novel sampled-data asynchronous fuzzy output feedback control approach for active suspension systems in restricted frequency domain.In order to better investigate uncertain suspension dynamics,th...This paper proposes a novel sampled-data asynchronous fuzzy output feedback control approach for active suspension systems in restricted frequency domain.In order to better investigate uncertain suspension dynamics,the sampleddata Takagi-Sugeno(T-S)fuzzy half-car active suspension(HCAS)system is considered,which is further modelled as a continuous system with an input delay.Firstly,considering that the fuzzy system and the fuzzy controller cannot share the identical premises due to the existence of input delay,a reconstructed method is employed to synchronize the time scales of membership functions between the fuzzy controller and the fuzzy system.Secondly,since external disturbances often belong to a restricted frequency range,a finite frequency control criterion is presented for control synthesis to reduce conservatism.Thirdly,given a full information of state variables is hardly available in practical suspension systems,a two-stage method is proposed to calculate the static output feedback control gains.Moreover,an iterative algorithm is proposed to compute the optimum solution.Finally,numerical simulations verify the effectiveness of the proposed controllers.展开更多
Regression testing is the process of validating modified software to provide confidence that the changed parts of the software behave as intended and that the unchanged parts have not been adversely affected by the mo...Regression testing is the process of validating modified software to provide confidence that the changed parts of the software behave as intended and that the unchanged parts have not been adversely affected by the modifications. The goal of regression testing is to reduce the test suit by testing the new characters and the modified parts of a program with the original test suit. Regression testing is a high cost testing method. This paper presents a regression testing selection technique that can reduce the test suit on the basis of Control Flow Graph (CFG). It import the inherit strategy of object-oriented language to ensure an edge’s control domain to reduce the test suit size effectively. We implement the idea by coding the edge. An algorithm is also presented at last.展开更多
In this paper, we consider a numerical approximation for the boundary optimal control problem with the control constraint governed by a heat equation defined in a variable domain. For this variable domain problem, the...In this paper, we consider a numerical approximation for the boundary optimal control problem with the control constraint governed by a heat equation defined in a variable domain. For this variable domain problem, the boundary of the domain is moving and the shape of theboundary is defined by a known time-dependent function. By making use of the Galerkin finite element method, we first project the original optimal control problem into a semi-discrete optimal control problem governed by a system of ordinary differential equations. Then, based on the aforementioned semi-discrete problem, we apply the control parameterization method to obtain an optimal parameter selection problem governed by a lumped parameter system, which can be solved as a nonlinear optimization problem by a Sequential Quadratic Programming （SQP） algorithm. The numerical simulation is given to illustrate the effectiveness of our numerical approximation for the variable domain problem with the finite element method and the control parameterization method.展开更多
Access control in multi-domain environments is an important question in building coalition between domains. Based on the RBAC access control model and the concepts of secure domain, the role delegation and role mappin...Access control in multi-domain environments is an important question in building coalition between domains. Based on the RBAC access control model and the concepts of secure domain, the role delegation and role mapping are proposed, which support the third-party authorization. A distributed RBAC model is then presented. Finally implementation issues are discussed.展开更多
For estimation group competition and multiagent coordination strategy, this paper introduces a notion based on multiagent group. According to the control domain, it analyzes the multiagent strategy during competition ...For estimation group competition and multiagent coordination strategy, this paper introduces a notion based on multiagent group. According to the control domain, it analyzes the multiagent strategy during competition in the macroscopic. It has been adopted in robot soccer and result enunciates that our method does not depend on competition result. It can objectively quantitatively estimate coordination strategy.展开更多
This paper studies a stochastically forced chemostat model with feedback control in which two organisms compete for a single growth-limiting substrate. In the deterministic counterpart, previous researches show that t...This paper studies a stochastically forced chemostat model with feedback control in which two organisms compete for a single growth-limiting substrate. In the deterministic counterpart, previous researches show that the coexistence of two competing organisms may be achieved as a stable positive equilibrium or a stable positive periodic solution by different feedback schedules. In the stochastic case, based on the stochastic sensitivity function technique,we construct the confidence domains for different feedback schedules which allow us to find the configurational arrangements of the stochastic attractors and analyze the dispersion of the random states of the stochastic model.展开更多
A time-domain electromagnetic transmitter（TDET） with great power and large current was designed by using a closed-loop phase shifting control strategy. A clamping voltage source circuit was applied in this system to...A time-domain electromagnetic transmitter（TDET） with great power and large current was designed by using a closed-loop phase shifting control strategy. A clamping voltage source circuit was applied in this system to improve the falling edge of emission current and shorten the turn-off time. The simulated results showed that this TDET exhibited the advantages including a large current, strong capability for rapid turn-off, stably output voltage, preferably dynamic performance, a widely adjustable range in transmitting voltage, accurate measurement precision.展开更多
We consider optimal control problems for the flow of gas in a pipe network. The equations of motions are taken to be represented by a semi-linear model derived from the fully nonlinear isothermal Euler gas equations. ...We consider optimal control problems for the flow of gas in a pipe network. The equations of motions are taken to be represented by a semi-linear model derived from the fully nonlinear isothermal Euler gas equations. We formulate an optimal control problem on a given network and introduce a time discretization thereof. We then study the well-posedness of the corresponding time-discrete optimal control problem. In order to further reduce the complexity, we consider an instantaneous control strategy. The main part of the paper is concerned with a non-overlapping domain decomposition of the semi-linear elliptic optimal control problem on the graph into local problems on a small part of the network, ultimately on a single edge.展开更多
We investigate the angular-dependent multi-mode resonance frequencies in CoZr magnetic thin films with a rotatable stripe domain structure.A variable range of multi-mode resonance frequencies from 1.86 GHz to 4.80 GHz...We investigate the angular-dependent multi-mode resonance frequencies in CoZr magnetic thin films with a rotatable stripe domain structure.A variable range of multi-mode resonance frequencies from 1.86 GHz to 4.80 GHz is achieved by pre-magnetizing the CoZr films along different azimuth directions,which can be ascribed to the competition between the uniaxial anisotropy caused by the oblique deposition and the rotatable anisotropy induced by the rotatable stripe domain.Furthermore,the regulating range of resonance frequency for the CoZr film can be adjusted by changing the oblique deposition angle.Our results might be beneficial for the applications of magnetic thin films in microwave devices.展开更多
Software-defined networking(SDN)makes network agile and flexible due to its programmable approach.An extensive network has multiple domains in SDN for the scalability and performance of the network.However,the inter-d...Software-defined networking(SDN)makes network agile and flexible due to its programmable approach.An extensive network has multiple domains in SDN for the scalability and performance of the network.However,the inter-domain link is also crucial for the stability of the entire network on the data plane layer.More than one inter-domain connection enhances the scalability of the data plane layer.However,it faces a reachability problem with the principal root,which causes forwarding loops and packet drops in the network,thereby degrading network performance.The proposed solution is a multiple controller architecture;however,this approach increases the complexity and affects network performance.Thus,in this study,we propose a framework that avoids forwarding loops and packet drops without the synchronization of multiple-domain controllers in the network using an avoid loop with test packet scheme.Moreover,we collect the link status for improved routing and load balancing for the upcoming flow across inter-domain links to prevent congestion and increase throughput in real time.Our proposed methodology can significantly reduce the controller workload against multiple controller architecture,minimize flow setup latency,and improve throughput.展开更多
The secure interaction among multiple security domains is a major concern. In this paper, we highlight the issues of secure interoperability among multiple security domains operating under the widely accepted Role Bas...The secure interaction among multiple security domains is a major concern. In this paper, we highlight the issues of secure interoperability among multiple security domains operating under the widely accepted Role Based Access Control （RBAC） model. We propose a model called CRBAC that easily establishes a global policy for roles mapping among multiple security domains. Our model is based on an extension of the RBAC model. Also, multiple security domains were composed to one abstract security domain. Also roles in the multiple domains are translated to permissions of roles in the abstract security domain. These permissions keep theirs hierarchies. The roles in the abstract security domain implement roles mapping among the multiple security domains. Then, authorized users of any security domain can transparently access resources in the multiple domains.展开更多
Based on trust measurement, a new cross-domain access control model is proposed to improve the security performance of the cross-domain access control processes. This model integrates the trust management and trusted ...Based on trust measurement, a new cross-domain access control model is proposed to improve the security performance of the cross-domain access control processes. This model integrates the trust management and trusted platform measurement, defines several concepts （user trust degree, platform configuration integrity and intra/inter-domain trust degree） and calculates them with users＇ uniform identity authentication and historical access behavior analysis. Then this model expands the extensible access control markup language （XACML） model by adding inside trust manager point （ITMP） and outside trust manager point （OTMP）, and describes the architectures and workflows of ITMP and OTMP in details. The experimental results show that this model can achieve more fine-grained access control, implement dynamic authorization in a simple way, and improve the security degrees of the cross-domain access control.展开更多
While Role-Based Access Control Model (RBAC) is being analyzed, the concept of Role of Time-domain Based Access Control Model (T-RBAC) is put forward. With time-domain added, both time-domain and authority control rol...While Role-Based Access Control Model (RBAC) is being analyzed, the concept of Role of Time-domain Based Access Control Model (T-RBAC) is put forward. With time-domain added, both time-domain and authority control roles. The basic idea of T-RBAC is introduced and described formally, and the safely of this model is analyzed. The research shows that T-RBAC fulfills both rules of information security, which are principle of least privilege and separation of duties. With practical application of T-RBCA, it can handle most of the time-related or authority-related problems. What’s more, it also increases the security level, flexibility and dynamic adaptation of the system and has lower complexity than system only handled by authority. This model also can solve conflicts caused by authority.展开更多
Dear Editor,This letter presents a class of saturated sliding mode control (SMC)strategy for linear systems subject to impulsive disturbance and input saturation. To ensure the feasibility of proposed SMC under satura...Dear Editor,This letter presents a class of saturated sliding mode control (SMC)strategy for linear systems subject to impulsive disturbance and input saturation. To ensure the feasibility of proposed SMC under saturation, a relationship is established among attraction domain, saturation structure and control gain.展开更多
Genetic disruption of the RAS binding domain(RBD)of Phosphoinositide 3-kinase alpha(PI3Kα)impairs the growth of tumors driven by the small guanosine triphosphatase RAS in mice and does not impact PI3Kα's role in...Genetic disruption of the RAS binding domain(RBD)of Phosphoinositide 3-kinase alpha(PI3Kα)impairs the growth of tumors driven by the small guanosine triphosphatase RAS in mice and does not impact PI3Kα's role in insulin mediated control of glucose homeostasis.Selectively blocking the RAS-PI3Kαinteraction may represent a strategy for treating RAS-dependent cancers as it would avoid the toxicity associated with inhibitors of PI3Kαlipid kinase activity.We developed compounds that bind covalently to cysteine 242 in the RBD of PI3K p110αand block RAS activation of PI3Kαactivity.In mice,inhibitors slow the growth of RAS mutant tumors and Human Epidermal Growth Factor Receptor 2(HER2)overexpressing tumors,particularly when combined with other inhibitors of the RAS/Mitogen-activated protein kinase pathway,without causing hyperglycemia.Oncogenic mutations in the small guanosine triphosphatase RAS occur in 20%of human cancers,with RAS proteins activating both the mitogen-activated protein kinase(MAPK)and Phosphoinositide 3-kinase(PI3K)pathways(1-3).As each of these pathways has oncogenic potential,simultaneous activation,as occurs in mutant RAS driven cancers,generates aggressive disease.In RAS-driven cell and animal models,inhibition of both the MAPK and PI3K pathways is more efficacious than targeting the individual pathways(4);however,dose-limiting toxicities in humans prevent clinical success of this strategy.展开更多
基金supported by the National Natural Science Foundation of China(22265021,52231007,and 12327804)the Aeronautical Science Foundation of China(2020Z056056003)Jiangxi Provincial Natural Science Foundation(20232BAB212004).
文摘The precise tuning of magnetic nanoparticle size and magnetic domains,thereby shaping magnetic properties.However,the dynamic evolution mechanisms of magnetic domain configurations in relation to electromagnetic(EM)attenuation behavior remain poorly understood.To address this gap,a thermodynamically controlled periodic coordination strategy is proposed to achieve precise modulation of magnetic nanoparticle spacing.This approach unveils the evolution of magnetic domain configurations,progressing from individual to coupled and ultimately to crosslinked domain configurations.A unique magnetic coupling phenomenon surpasses the Snoek limit in low-frequency range,which is observed through micromagnetic simulation.The crosslinked magnetic configuration achieves effective low-frequency EM wave absorption at 3.68 GHz,encompassing nearly the entire C-band.This exceptional magnetic interaction significantly enhances radar camouflage and thermal insulation properties.Additionally,a robust gradient metamaterial design extends coverage across the full band(2–40 GHz),effectively mitigating the impact of EM pollution on human health and environment.This comprehensive study elucidates the evolution mechanisms of magnetic domain configurations,addresses gaps in dynamic magnetic modulation,and provides novel insights for the development of high-performance,low-frequency EM wave absorption materials.
基金supported by National Natural Science Foundation of China[grant numbers 61573233]Natural Science Foundation of Guangdong,China[grant numbers 2021A1515010661]+1 种基金Special projects in key fields of colleges and universities in Guangdong Province[grant numbers 2020ZDZX2005]Innovation Team Project of University in Guangdong Province[grant numbers 2015KCXTD018].
文摘A fast image segmentation algorithm based on salient features model and spatial-frequency domain adaptive kernel is proposed to solve the accurate discriminate objects problem of online visual detection in such scenes of variable sample morphological characteristics,low contrast and complex background texture.Firstly,by analyzing the spectral component distribution and spatial contour feature of the image,a salient feature model is established in spatial-frequency domain.Then,the salient object detection method based on Gaussian band-pass filter and the design criterion of adaptive convolution kernel are proposed to extract the salient contour feature of the target in spatial and frequency domain.Finally,the selection and growth rules of seed points are improved by integrating the gray level and contour features of the target,and the target is segmented by seeded region growing.Experiments have been performed on Berkeley Segmentation Data Set,as well as sample images of online detection,to verify the effectiveness of the algorithm.The experimental results show that the Jaccard Similarity Coefficient of the segmentation is more than 90%,which indicates that the proposed algorithm can availably extract the target feature information,suppress the background texture and resist noise interference.Besides,the Hausdorff Distance of the segmentation is less than 10,which infers that the proposed algorithm obtains a high evaluation on the target contour preservation.The experimental results also show that the proposed algorithm significantly improves the operation efficiency while obtaining comparable segmentation performance over other algorithms.
文摘To study the domain decomposition algorithms for the equations of elliptic type, the method of optimal boundary control was used to advance a new procedure for domain decomposition algorithms and regularization method to deal with the ill posedness of the control problem. The determination of the value of the solution of the partial differential equation on the interface——the key of the domain decomposition algorithms——was transformed into a boundary control problem and the ill posedness of the control problem was overcome by regularization. The convergence of the regularizing control solution was proven and the equations which characterize the optimal control were given therefore the value of the unknown solution on the interface of the domain would be obtained by solving a series of coupling equations. Using the boundary control method the domain decomposion algorithm can be carried out.
文摘In order to understand the community capacity for sustainable community-based dengue prevention and control,this paper proposes the approach of a previous study about meaning and domains of dengue prevention and control,an assessment tool and a community capacity building model for sustainable community-based dengue prevention and control in the Southern Thailand. A study of dengue community capacity domains was conducted by utilizing a qualitative method, whereby ten initial community domains were identified by means of a literature review,in-depth interviews of sixty community leaders,and eight focus group discussions with sixty non-leaders in four sub-districts of southern Thailand.In the final study,there were 14 identifiable domains in leaders group and 11 domains in non-leaders.The resulting dengue community capacity-assessment tool(DCCAT) consisted of two parts:one for leaders(DCCAT-L) and the other for non-leaders (DCCAT-NL).DCCAT-L was composed of 115 items within 14 domains and 83 items within 11 domains for the DCCAT-NL.The key domains of leaders and non-leaders had a partial overlap of domains such as critical situation management,personal leadership,health care provider capacity,needs assessment,senses of community,leader group networking,communication of dengue information,community leadership,religious capacity,leader group and community networking,resource mobilization,dengue working group,community participation,and continuing activities.The application of the new tool consisted of five steps:1) community preparation,2) assessment,3) a community hearing meeting,4) interventions,and 5) conclusion and improvement step.All stakeholders in the community should use the new tool based on a clear understanding of the measurement objectives,the desired outcomes,resources available and characteristics of their community.If communities need to develop and build dengue community capacity,then the designed pre-post intervention assessments or serial assessments are essential.
基金supported by the National Natural Science Foundation of China(51705084)the Natural Science Foundation of Guangdong Province of China(2018A030313999,2019A1515011602)+2 种基金the Fundamental Research Funds for the Central Universities(2018MS46,N2003032)the Opening Project of Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing,South China University of Technology(2019kfkt06)the Research Grants of the University of Macao(MYRG2017-00135-FST,MYRG2019-00028-FST)。
文摘This paper proposes a novel sampled-data asynchronous fuzzy output feedback control approach for active suspension systems in restricted frequency domain.In order to better investigate uncertain suspension dynamics,the sampleddata Takagi-Sugeno(T-S)fuzzy half-car active suspension(HCAS)system is considered,which is further modelled as a continuous system with an input delay.Firstly,considering that the fuzzy system and the fuzzy controller cannot share the identical premises due to the existence of input delay,a reconstructed method is employed to synchronize the time scales of membership functions between the fuzzy controller and the fuzzy system.Secondly,since external disturbances often belong to a restricted frequency range,a finite frequency control criterion is presented for control synthesis to reduce conservatism.Thirdly,given a full information of state variables is hardly available in practical suspension systems,a two-stage method is proposed to calculate the static output feedback control gains.Moreover,an iterative algorithm is proposed to compute the optimum solution.Finally,numerical simulations verify the effectiveness of the proposed controllers.
基金This work was supported by Shanghai Municipal Science and Technology commission No.04ZR14105and Shanghai UniversitiesTechnology Development Foundation No.2002DZ46
文摘Regression testing is the process of validating modified software to provide confidence that the changed parts of the software behave as intended and that the unchanged parts have not been adversely affected by the modifications. The goal of regression testing is to reduce the test suit by testing the new characters and the modified parts of a program with the original test suit. Regression testing is a high cost testing method. This paper presents a regression testing selection technique that can reduce the test suit on the basis of Control Flow Graph (CFG). It import the inherit strategy of object-oriented language to ensure an edge’s control domain to reduce the test suit size effectively. We implement the idea by coding the edge. An algorithm is also presented at last.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61374096 and 61104048)the Natural Science Foundation of Zhejiang Province of China(Grant No.Y6110751)
文摘In this paper, we consider a numerical approximation for the boundary optimal control problem with the control constraint governed by a heat equation defined in a variable domain. For this variable domain problem, the boundary of the domain is moving and the shape of theboundary is defined by a known time-dependent function. By making use of the Galerkin finite element method, we first project the original optimal control problem into a semi-discrete optimal control problem governed by a system of ordinary differential equations. Then, based on the aforementioned semi-discrete problem, we apply the control parameterization method to obtain an optimal parameter selection problem governed by a lumped parameter system, which can be solved as a nonlinear optimization problem by a Sequential Quadratic Programming （SQP） algorithm. The numerical simulation is given to illustrate the effectiveness of our numerical approximation for the variable domain problem with the finite element method and the control parameterization method.
文摘Access control in multi-domain environments is an important question in building coalition between domains. Based on the RBAC access control model and the concepts of secure domain, the role delegation and role mapping are proposed, which support the third-party authorization. A distributed RBAC model is then presented. Finally implementation issues are discussed.
文摘For estimation group competition and multiagent coordination strategy, this paper introduces a notion based on multiagent group. According to the control domain, it analyzes the multiagent strategy during competition in the macroscopic. It has been adopted in robot soccer and result enunciates that our method does not depend on competition result. It can objectively quantitatively estimate coordination strategy.
基金Supported by the National Natural Science Foundation of China(11671260,11801224)Natural Science Foundation of Jiangsu Province(BK20180856)
文摘This paper studies a stochastically forced chemostat model with feedback control in which two organisms compete for a single growth-limiting substrate. In the deterministic counterpart, previous researches show that the coexistence of two competing organisms may be achieved as a stable positive equilibrium or a stable positive periodic solution by different feedback schedules. In the stochastic case, based on the stochastic sensitivity function technique,we construct the confidence domains for different feedback schedules which allow us to find the configurational arrangements of the stochastic attractors and analyze the dispersion of the random states of the stochastic model.
基金Supported by the National Natural Science Foundation of China(51277189)the Chongqing Education Committee Science and Technology Research Projects(KJ1401208)
文摘A time-domain electromagnetic transmitter（TDET） with great power and large current was designed by using a closed-loop phase shifting control strategy. A clamping voltage source circuit was applied in this system to improve the falling edge of emission current and shorten the turn-off time. The simulated results showed that this TDET exhibited the advantages including a large current, strong capability for rapid turn-off, stably output voltage, preferably dynamic performance, a widely adjustable range in transmitting voltage, accurate measurement precision.
文摘We consider optimal control problems for the flow of gas in a pipe network. The equations of motions are taken to be represented by a semi-linear model derived from the fully nonlinear isothermal Euler gas equations. We formulate an optimal control problem on a given network and introduce a time discretization thereof. We then study the well-posedness of the corresponding time-discrete optimal control problem. In order to further reduce the complexity, we consider an instantaneous control strategy. The main part of the paper is concerned with a non-overlapping domain decomposition of the semi-linear elliptic optimal control problem on the graph into local problems on a small part of the network, ultimately on a single edge.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51871117 and 51671099)the Program for Changjiang Scholars and Innovative Research Team in University,China(Grant No.IRT-16R35)the Gansu Provincial Science Foundation for Distinguished Young Scholars,China(Grant No.20JR10RA649).
文摘We investigate the angular-dependent multi-mode resonance frequencies in CoZr magnetic thin films with a rotatable stripe domain structure.A variable range of multi-mode resonance frequencies from 1.86 GHz to 4.80 GHz is achieved by pre-magnetizing the CoZr films along different azimuth directions,which can be ascribed to the competition between the uniaxial anisotropy caused by the oblique deposition and the rotatable anisotropy induced by the rotatable stripe domain.Furthermore,the regulating range of resonance frequency for the CoZr film can be adjusted by changing the oblique deposition angle.Our results might be beneficial for the applications of magnetic thin films in microwave devices.
基金The authors are grateful to the University of Malakand and University ofMalaya for providing fund for this project.The authors are grateful to the Taif University Researchers Supporting Project(number TURSP-2020/36),Taif University,Taif,Saudi ArabiaThis research work was also partially supported by the Faculty of Computer Science and Information Technology,University of Malaya,under Postgraduate Research Grant PG035-2016A.
文摘Software-defined networking(SDN)makes network agile and flexible due to its programmable approach.An extensive network has multiple domains in SDN for the scalability and performance of the network.However,the inter-domain link is also crucial for the stability of the entire network on the data plane layer.More than one inter-domain connection enhances the scalability of the data plane layer.However,it faces a reachability problem with the principal root,which causes forwarding loops and packet drops in the network,thereby degrading network performance.The proposed solution is a multiple controller architecture;however,this approach increases the complexity and affects network performance.Thus,in this study,we propose a framework that avoids forwarding loops and packet drops without the synchronization of multiple-domain controllers in the network using an avoid loop with test packet scheme.Moreover,we collect the link status for improved routing and load balancing for the upcoming flow across inter-domain links to prevent congestion and increase throughput in real time.Our proposed methodology can significantly reduce the controller workload against multiple controller architecture,minimize flow setup latency,and improve throughput.
基金Supported by the National Natural Science Foun-dation of China(60403027) the Natural Science Foundation of HubeiProvince(2005ABA258) the Open Foundation of State Key Labo-ratory of Software Engineering(SKLSE05-07)
文摘The secure interaction among multiple security domains is a major concern. In this paper, we highlight the issues of secure interoperability among multiple security domains operating under the widely accepted Role Based Access Control （RBAC） model. We propose a model called CRBAC that easily establishes a global policy for roles mapping among multiple security domains. Our model is based on an extension of the RBAC model. Also, multiple security domains were composed to one abstract security domain. Also roles in the multiple domains are translated to permissions of roles in the abstract security domain. These permissions keep theirs hierarchies. The roles in the abstract security domain implement roles mapping among the multiple security domains. Then, authorized users of any security domain can transparently access resources in the multiple domains.
基金Supported by the National Key Technology Support Program of China(2013BAK07B04)the Natural Science Foundation of Hebei Province(F2014201152)
文摘Based on trust measurement, a new cross-domain access control model is proposed to improve the security performance of the cross-domain access control processes. This model integrates the trust management and trusted platform measurement, defines several concepts （user trust degree, platform configuration integrity and intra/inter-domain trust degree） and calculates them with users＇ uniform identity authentication and historical access behavior analysis. Then this model expands the extensible access control markup language （XACML） model by adding inside trust manager point （ITMP） and outside trust manager point （OTMP）, and describes the architectures and workflows of ITMP and OTMP in details. The experimental results show that this model can achieve more fine-grained access control, implement dynamic authorization in a simple way, and improve the security degrees of the cross-domain access control.
文摘While Role-Based Access Control Model (RBAC) is being analyzed, the concept of Role of Time-domain Based Access Control Model (T-RBAC) is put forward. With time-domain added, both time-domain and authority control roles. The basic idea of T-RBAC is introduced and described formally, and the safely of this model is analyzed. The research shows that T-RBAC fulfills both rules of information security, which are principle of least privilege and separation of duties. With practical application of T-RBCA, it can handle most of the time-related or authority-related problems. What’s more, it also increases the security level, flexibility and dynamic adaptation of the system and has lower complexity than system only handled by authority. This model also can solve conflicts caused by authority.
基金supported by the National Natural Science Foundation of China(62173215)the Major Basic Research Program of the Natural Science Foundation of Shandong Province in China(ZR2021ZD04,ZR2020ZD24)
文摘Dear Editor,This letter presents a class of saturated sliding mode control (SMC)strategy for linear systems subject to impulsive disturbance and input saturation. To ensure the feasibility of proposed SMC under saturation, a relationship is established among attraction domain, saturation structure and control gain.
文摘Genetic disruption of the RAS binding domain(RBD)of Phosphoinositide 3-kinase alpha(PI3Kα)impairs the growth of tumors driven by the small guanosine triphosphatase RAS in mice and does not impact PI3Kα's role in insulin mediated control of glucose homeostasis.Selectively blocking the RAS-PI3Kαinteraction may represent a strategy for treating RAS-dependent cancers as it would avoid the toxicity associated with inhibitors of PI3Kαlipid kinase activity.We developed compounds that bind covalently to cysteine 242 in the RBD of PI3K p110αand block RAS activation of PI3Kαactivity.In mice,inhibitors slow the growth of RAS mutant tumors and Human Epidermal Growth Factor Receptor 2(HER2)overexpressing tumors,particularly when combined with other inhibitors of the RAS/Mitogen-activated protein kinase pathway,without causing hyperglycemia.Oncogenic mutations in the small guanosine triphosphatase RAS occur in 20%of human cancers,with RAS proteins activating both the mitogen-activated protein kinase(MAPK)and Phosphoinositide 3-kinase(PI3K)pathways(1-3).As each of these pathways has oncogenic potential,simultaneous activation,as occurs in mutant RAS driven cancers,generates aggressive disease.In RAS-driven cell and animal models,inhibition of both the MAPK and PI3K pathways is more efficacious than targeting the individual pathways(4);however,dose-limiting toxicities in humans prevent clinical success of this strategy.
