This paper addresses the robust admissibility problem in singular fractional-order continuous time systems. It is based on new admissibility conditions of singular fractional-order systems expressed in a set of strict...This paper addresses the robust admissibility problem in singular fractional-order continuous time systems. It is based on new admissibility conditions of singular fractional-order systems expressed in a set of strict linear matrix inequalities (LMIs). Then, a static output feedback controller is designed for the uncertain closed-loop system to be admissible. Numerical examples are given to illustrate the proposed methods.展开更多
In the current real life, systems theory is an abstract background of systems thinking,which is a part of systemic behavior. The systemic behavior is the alternative to the currently prevailing one-sidedness that puts...In the current real life, systems theory is an abstract background of systems thinking,which is a part of systemic behavior. The systemic behavior is the alternative to the currently prevailing one-sidedness that puts all of humankind in danger of self-destruction due to the crucial over-sights(all the way to world wars) that unavoidably result from the current over-specialization(along with crucial, but partial insights), if the specialists fail to practice creative interdisciplinary cooperation.This contribution is a next phase of research after the contributions by Matja? Mulej, Zdenka ?enko and Viktor ?akelj(2017) and by Matja? Mulej, et al.(2013). Although the abstract background and thinking that the systemic behavior applies, are very necessary, theory and thinking are no longer enough for systems science to be a relevant science and practice helping humankind find the way out from the current blind alley and survive as a healthy civilization with a healthy social and natural environment. The suggestion in this contribution therefore reads: Let us systems and cybernetics scientists make/enable the transition to systemic behavior, which applies all the many theories, which are components in the background of systemic behavior in practice, next to each other and/or in synergy. Analysis, i.e., studying per isolated parts is too overlooking and one-sided to be enough. So is teaching on a single one out of several systems theories. Reality is too complex. Teaching is a part of this necessary effort, which must lead to a global peace and survival of humankind of today instead of the current hating the human descendants.展开更多
The rapid pace of technological change has seen information and communication technologies become the digital backbone of developed nations’ economies and a pre-requisite for global trade. Some enterprise systems are...The rapid pace of technological change has seen information and communication technologies become the digital backbone of developed nations’ economies and a pre-requisite for global trade. Some enterprise systems are however more than mere facilitators, they provide the bedrock without which organizations could not function;we term these mandatory systems “non-volitional”(NVS). With hyper-growth in demand for connectivity, telecommunications are typical of sectors where NVS shape the fiercely competitive landscape. Among them, Billing & Revenue Management Systems (BRMS) are a form of credit, providers deliver a service and subscribers later pay for that service. As such, they are “business critical”, meaning failures may affect an organization’s ability to conduct its core business. Failures also impact user satisfaction, a key measure of information systems success. However, relatively few studies empirically test this notion;fewer still evaluate it at organizational (rather than individual) level, while there is a dearth of literature investigating non-volitional systems and, to the best of our knowledge, none whatsoever consider ways of predicting user satisfaction for BRMS. According to a renowned and widely cited conceptual model, user satisfaction is influenced by information, system, and service quality respectively. To test this theory for telecoms BRMS, we applied structural equation modelling to investigate which of these dimensions has the most effect. The results indicate that information quality, system quality, service quality, and user satisfaction are all valid measures of BRMS success. Hypothesized relationships between the four success dimensions were significantly substantiated. The study also identified five measures of information quality, four measures of system quality, four measures of service quality, and four measures of user satisfaction. Once the proposed model had been successfully validated, we tested the level of significance among user satisfaction and the three quality展开更多
The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We used therefore start-up experiments with constant shear r...The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We used therefore start-up experiments with constant shear rates and can speak consequently of shear stress instead of viscosity.The shear stress increases sharply at the beginning of the stress growth experiment,passes an overshoot and begins to decrease up to the steady state shear stress.We can assume that a stress growth curve with an overshoot points out to thixotropic behavior.After the steady state shear stress is reached,the shear deformation is stopped,and the stress relaxation begins.It is to be expected that the shear stress will recover after the stress relaxation.Systems with shear thinning and plastic flow behavior were examined.The thixotropy is discussed in relation to the flow behavior.Stress growth experiments were performed with shear rates from the first Newtonian region and from the shear thinning region of the systems with shear thinning flow behavior.Stress start-up experiments were carrying out with shear rates from the first and second yield stress regions and from the transition section of a system with plastic flow behavior.展开更多
Dear editor, In certain practical systems, quantized control can effectively solve stabilization problems in intelligent transportation systems and digital systems [1]. Constant progress has been made on linear quanti...Dear editor, In certain practical systems, quantized control can effectively solve stabilization problems in intelligent transportation systems and digital systems [1]. Constant progress has been made on linear quantization systems. The problems of input quantization and output quantization were studied in [2] for the class of linear systems using a logarithmic quantizer, and the problem of quadratic stabilization was addressed by a proposed condition. On the contrary, research on nonlinear quantization systems is very significant and certain researches for nonlinear quantization systems are available [3,4].展开更多
In a study of gerbils with contrasting social and mating systems (group-living monogamous Mongolian gerbil Meriones unguiculatus, solitary nonterritorial promiscuous midday jird M. meridianus, and solitary territorial...In a study of gerbils with contrasting social and mating systems (group-living monogamous Mongolian gerbil Meriones unguiculatus, solitary nonterritorial promiscuous midday jird M. meridianus, and solitary territorial promiscuous pale gerbil Gerbillus perpallidus), we employed part ner pref ere nee tests (PPTs) to assess among-species variation in sociability and pair-bonding patterns and tested whether the nature of contact between individuals: direct contact (DC) versus nondirect contact (NDC) affected our results. We measured male pref ere nces as the time: 1) spe nt alone, 2) with familiar (partner), and 3) unfamiliar (stranger) female in the 3-chambered apparatus. Gerbil species differed strongly in sociability and male partner preferences. The time spent alone was a reliable indicator of species sociability indepe ndent of the nature of con tact, whereas the pattern and level of betwee n-species differe nces in male partner preferences depended on con tact type: DC PPTs, un like NDC-tests, discriminated well betwee n monogamous and promiscuous species. In the DC-tests, stranger-directed aggression and stranger avoidanee were observed both in the highly social monogamous M. unguiculatus and the solitary territorial promiscuous G. perpallidus, but not in the non territorial promiscuous M. meridianus. In M. unguiculatus, stranger avoidanee in the DC-tests increased the time spent with the partner, thus providing evidence of a partner preference that was not found in the NDC-tests, whereas in G. perpallidus, stran ger avoidance in creased the time spe nt alone. This first comparative experimental study of partner prefere nces in gerbils provides new in sights into the in terspecific variation in gerbil sociality and mating systems and sheds light on behavioral mechanisms un derlyi ng social fidelity and pair-b on ding.展开更多
This study explores a stable model order reduction method for fractional-order systems. Using the unsymmetric Lanczos algorithm, the reduced order system with a certain number of matched moments is generated. To obtai...This study explores a stable model order reduction method for fractional-order systems. Using the unsymmetric Lanczos algorithm, the reduced order system with a certain number of matched moments is generated. To obtain a stable reduced order system, the stable model order reduction procedure is discussed. By the revised operation on the tridiagonal matrix produced by the unsymmetric Lanczos algorithm, we propose a reduced order modeling method for a fractional-order system to achieve a satisfactory fitting effect with the original system by the matched moments in the frequency domain. Besides, the bound function of the order reduction error is offered. Two numerical examples are presented to illustrate the effectiveness of the proposed method.展开更多
The growth of environmental energy harvesting has been explosive in wireless computing systems especially when replacing or recharging batteries manually is impracticable.This work investigates the scheduling of perio...The growth of environmental energy harvesting has been explosive in wireless computing systems especially when replacing or recharging batteries manually is impracticable.This work investigates the scheduling of periodic weekly hard real-time tasks under energy constraints.Based on this motivation,we proposed a real-time scheduling algorithm,namely energy guarantee dynamic voltage and frequency scaling(EG-DVFS),that utilizes the earliest deadline-harvesting(ED-H)scheduling algorithm combined with dynamic voltage and frequency scaling.This one is qualified as real-time since tasks must satisfy their timing constraints.We assume that the preemptable tasks receive dynamic priorities according to the earliest deadline first(EDF)rule.EG-DVFS adjusts the processor's behavior by characterizing the properties of the energy source module,capacity of the stored energy as well as the harvested energy in a future duration.Specifically,tasks are executed at full processor speed if the amount of energy in the battery is enough to finish its execution.Otherwise,the processor slows down task execution to the lowest possible processor speed while still guaranteeing to meet all the timing constraints.EG-DVFS mainly depends on the on-line computation of the slack time and the slack energy with dynamic voltage and frequency selection in order to achieve an improved system performance.Experimental results show that EG-DVFS can achieve capacity savings up of up to 33%when compared to ED-H.展开更多
As a continuation of last four years’ special sections on software systems, this special section encourages and promotes research to address challenges from the perspective of software systems. The goal of this speci...As a continuation of last four years’ special sections on software systems, this special section encourages and promotes research to address challenges from the perspective of software systems. The goal of this special section is to present state-of-the-art and high-quality original research in the area of software systems. Different from previous special sections, this special section includes two different major themes: 1) Internetware and Beyond;2) Trustworthy Computing Systems and Networks.展开更多
Abs tract: A fundamental aspect of society is the exchange and discussion of opinions bet ween individuals, occurring in situations as varied as company boardrooms, eleme nt ary school classrooms and online social med...Abs tract: A fundamental aspect of society is the exchange and discussion of opinions bet ween individuals, occurring in situations as varied as company boardrooms, eleme nt ary school classrooms and online social media. After a very brief introduction to the established results of the most fundamental opinion dynamics models, which seek to mathematically capture observed social phenomena, a brief discussion follows on several recent themes pursued by the authors building on the fundamental ideas. In the first theme, we study the way an individuaFs self-confidence can develop through contributing to discussions on a sequence of topics, reaching a consensus in each case, where the consensus value to some degree reflects the contribution of that individual to the conclusion. During this process, the individuals in the network and the way they interact can change. The second theme introduces a novel discrete-time model of opinion dynamics to study how discrepancies between an individual's expressed and private opinions can arise due to stubbornness and a pressure to conform to a social norm. It is also shown that a few extremists can create "pluralistic ignorance^^, where people believe there is majority support for a position but in fact the position is privately rejected by the majority. Last, we consider a group of individuals discussing a collection of logically related topics. In particular, we identify that for topics whose logical interdependencies take on a cascade structure, disagreement in opinions can occur if individuals have competing and/or heterogeneous views on how the topics are related, i.e., the logical interdependence structure varies between individuals.展开更多
A simulation model enables manufacturers to accurately evaluate the performance of their manufacturing systems.A vital input to build simulation models of manufacturing systems is the system behaviour,which is modelle...A simulation model enables manufacturers to accurately evaluate the performance of their manufacturing systems.A vital input to build simulation models of manufacturing systems is the system behaviour,which is modelled based on extensive data on manufacturing systems and their elements.However,for outsourced manufacturing systems,data provided from external suppliers to manufacturers are generally limited and insufficient.Therefore,a solution is required to identify and secure system behaviour from available data.We propose herein a behaviour extraction process along with detailed activities and diagrams to extract system behaviour from limited data.By using the systems engineering standard ANSI/EIA-632,the proposed process systematically restructures available data on a manufacturing system and its elements and then provides complete system behaviour to build a simulation model.A case study on a cooling water control system in a hot strip mill convincingly demonstrates the applicability and effectiveness of the proposed process.展开更多
The objective of this paper is to propose a reduced-order observer for a class of Lipschitz nonlinear discrete-time systems.The conditions that guarantee the existence of this observer are presented in the form of lin...The objective of this paper is to propose a reduced-order observer for a class of Lipschitz nonlinear discrete-time systems.The conditions that guarantee the existence of this observer are presented in the form of linear matrix inequalities(LMIs). To handle the Lipschitz nonlinearities, the Lipschitz condition and the Young′s relation are adequately operated to add more degrees of freedom to the proposed LMI. Necessary and sufficient conditions for the existence of the unbiased reduced-order observer are given. An extension to H_∞ performance analysis is considered in order to deal with H_∞ asymptotic stability of the estimation error in the presence of disturbances that affect the state of the system. To highlight the effectiveness of the proposed design methodology, three numerical examples are considered. Then, high performances are shown through real time implementation using the ARDUINO MEGA 2560 device.展开更多
This paper reports the boundedness and stability of highly nonlinear hybrid neutral stochastic differential delay equations(NSDDEs) with multiple delays. Without imposing linear growth condition, the boundedness and e...This paper reports the boundedness and stability of highly nonlinear hybrid neutral stochastic differential delay equations(NSDDEs) with multiple delays. Without imposing linear growth condition, the boundedness and exponential stability of the exact solution are investigated by Lyapunov functional method.In particular, using the M-matrix technique, the mean square exponential stability is obtained. Finally, three examples are presented to verify our results.展开更多
In this paper we study the saturated fusion systems over a direct product of the extraspecial group of order p^3 of exponent p and a finite abelian p-group. The result provides some new exotic fusion systems, whose un...In this paper we study the saturated fusion systems over a direct product of the extraspecial group of order p^3 of exponent p and a finite abelian p-group. The result provides some new exotic fusion systems, whose unique components are isomorphic to the exotic fusion systems over 7+^1+2 found by Ruiz and Viruel.展开更多
This paper addresses the stability problem associated with a class of sw计ched positive nonlinear systems in which each vector field is homogeneous,cooperative,and irreducible.Instead of using the Lyapunov function ap...This paper addresses the stability problem associated with a class of sw计ched positive nonlinear systems in which each vector field is homogeneous,cooperative,and irreducible.Instead of using the Lyapunov function approach,we fully establish the invariant ray analysis method to establish several stability conditions that depend on the states,rays,and/or times.We illustrate the efficiency of our proposed approach using the example of a chemical reaction.展开更多
Asymptotic stability of nonlinear fractional order affine systems with bounded inputs is dealt.The main contribution is to design a new bounded fractional order chattering free sliding mode controller in which the sys...Asymptotic stability of nonlinear fractional order affine systems with bounded inputs is dealt.The main contribution is to design a new bounded fractional order chattering free sliding mode controller in which the system states converge to the sliding surface at a determined finite time.To eliminate the chattering in the sliding mode and make the input controller bounded,hyperbolic tangent is used for designing the proposed fractional order sliding surface.Finally,the stability of the closed loop system using this bounded sliding mode controller is guaranteed by Lyapunov theory.A comparison with the integer order case is then presented and fractional order nonlinear polynomial systems are also studied as the special case.Finally,simulation results are provided to show the effectiveness of the designed controller.展开更多
State convergence is a novel control algorithm for bilateral teleoperation of robotic systems. First, it models the teleoperation system on state space and considers all the possible interactions between the master an...State convergence is a novel control algorithm for bilateral teleoperation of robotic systems. First, it models the teleoperation system on state space and considers all the possible interactions between the master and slave systems. Second, it presents an elegant design procedure which requires a set of equations to be solved in order to compute the control gains of the bilateral loop. These design conditions are obtained by turning the master-slave error into an autonomous system and imposing the desired dynamic behavior of the teleoperation system. Resultantly, the convergence of master and slave states is achieved in a well-defined manner. The present study aims at achieving a similar convergence behavior offered by state convergence controller while reducing the number of variables sent across the communication channel. The proposal suggests transmitting composite master and slave variables instead of full master and slave states while keeping the operator's force channel intact. We show that,with these composite and force variables;it is indeed possible to achieve the convergence of states in a desired way by strictly following the method of state convergence. The proposal leads to a reduced complexity state convergence algorithm which is termed as composite state convergence controller. In order to validate the proposed scheme in the absence and presence of communication time delays, MATLAB simulations and semi-real time experiments are performed on a single degree-of-freedom teleoperation system.展开更多
A.Submission The Journal publishes papers that are addressed to the theory,methodology and applications relating to systems science and systems engineering.All papers relating to these areas are welcome.1)Please email...A.Submission The Journal publishes papers that are addressed to the theory,methodology and applications relating to systems science and systems engineering.All papers relating to these areas are welcome.1)Please email your manuscript in.doc or.pdf format to jssse@mail.tsinghua.edu.cn for the reviewing process.The manuscript should be complete,including all tables and illustrations,and be prepared in the style described below.2)The manuscript should be double-blind,which means(a)all authors5 names and institutions must be removed,(b)all acknowledgments in the text must be removed.展开更多
Stochastic iterative learning control(ILC) is designed for solving the tracking problem of stochastic linear systems through fading channels. Consequently, the signals used in learning control algorithms are faded in ...Stochastic iterative learning control(ILC) is designed for solving the tracking problem of stochastic linear systems through fading channels. Consequently, the signals used in learning control algorithms are faded in the sense that a random variable is multiplied by the original signal. To achieve the tracking objective, a two-dimensional Kalman filtering method is used in this study to derive a learning gain matrix varying along both time and iteration axes. The learning gain matrix minimizes the trace of input error covariance. The asymptotic convergence of the generated input sequence to the desired input value is strictly proved in the mean-square sense. Both output and input fading are accounted for separately in turn, followed by a general formulation that both input and output fading coexists.Illustrative examples are provided to verify the effectiveness of the proposed schemes.展开更多
This paper presents a new Long-range generalized predictive controller in the synchronous reference frame for a wind energy system doubly-fed induction generator based. This controller uses the state space equations t...This paper presents a new Long-range generalized predictive controller in the synchronous reference frame for a wind energy system doubly-fed induction generator based. This controller uses the state space equations that consider the rotor current and voltage as state and control variables, to execute the predictive control action. Therefore, the model of the plant must be transformed into two discrete transference functions, by means of an auto-regressive moving average model, in order to attain a discrete and decoupled controller, which makes it possible to treat it as two independent single-input single-output systems instead of a magnetic coupled multiple-input multiple-output system. For achieving that, a direct power control strategy is used, based on the past and future rotor currents and voltages estimation. The algorithm evaluates the rotor current predictors for a defined prediction horizon and computes the new rotor voltages that must be injected to controlling the stator active and reactive powers. To evaluate the controller performance, some simulations were made using Matlab/Simulink. Experimental tests were carried out with a small-scale prototype assuming normal operating conditions with constant and variable wind speed profiles. Finally, some conclusions respect to the dynamic performance of this new controller are summarized.展开更多
文摘This paper addresses the robust admissibility problem in singular fractional-order continuous time systems. It is based on new admissibility conditions of singular fractional-order systems expressed in a set of strict linear matrix inequalities (LMIs). Then, a static output feedback controller is designed for the uncertain closed-loop system to be admissible. Numerical examples are given to illustrate the proposed methods.
文摘In the current real life, systems theory is an abstract background of systems thinking,which is a part of systemic behavior. The systemic behavior is the alternative to the currently prevailing one-sidedness that puts all of humankind in danger of self-destruction due to the crucial over-sights(all the way to world wars) that unavoidably result from the current over-specialization(along with crucial, but partial insights), if the specialists fail to practice creative interdisciplinary cooperation.This contribution is a next phase of research after the contributions by Matja? Mulej, Zdenka ?enko and Viktor ?akelj(2017) and by Matja? Mulej, et al.(2013). Although the abstract background and thinking that the systemic behavior applies, are very necessary, theory and thinking are no longer enough for systems science to be a relevant science and practice helping humankind find the way out from the current blind alley and survive as a healthy civilization with a healthy social and natural environment. The suggestion in this contribution therefore reads: Let us systems and cybernetics scientists make/enable the transition to systemic behavior, which applies all the many theories, which are components in the background of systemic behavior in practice, next to each other and/or in synergy. Analysis, i.e., studying per isolated parts is too overlooking and one-sided to be enough. So is teaching on a single one out of several systems theories. Reality is too complex. Teaching is a part of this necessary effort, which must lead to a global peace and survival of humankind of today instead of the current hating the human descendants.
文摘The rapid pace of technological change has seen information and communication technologies become the digital backbone of developed nations’ economies and a pre-requisite for global trade. Some enterprise systems are however more than mere facilitators, they provide the bedrock without which organizations could not function;we term these mandatory systems “non-volitional”(NVS). With hyper-growth in demand for connectivity, telecommunications are typical of sectors where NVS shape the fiercely competitive landscape. Among them, Billing & Revenue Management Systems (BRMS) are a form of credit, providers deliver a service and subscribers later pay for that service. As such, they are “business critical”, meaning failures may affect an organization’s ability to conduct its core business. Failures also impact user satisfaction, a key measure of information systems success. However, relatively few studies empirically test this notion;fewer still evaluate it at organizational (rather than individual) level, while there is a dearth of literature investigating non-volitional systems and, to the best of our knowledge, none whatsoever consider ways of predicting user satisfaction for BRMS. According to a renowned and widely cited conceptual model, user satisfaction is influenced by information, system, and service quality respectively. To test this theory for telecoms BRMS, we applied structural equation modelling to investigate which of these dimensions has the most effect. The results indicate that information quality, system quality, service quality, and user satisfaction are all valid measures of BRMS success. Hypothesized relationships between the four success dimensions were significantly substantiated. The study also identified five measures of information quality, four measures of system quality, four measures of service quality, and four measures of user satisfaction. Once the proposed model had been successfully validated, we tested the level of significance among user satisfaction and the three quality
文摘The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We used therefore start-up experiments with constant shear rates and can speak consequently of shear stress instead of viscosity.The shear stress increases sharply at the beginning of the stress growth experiment,passes an overshoot and begins to decrease up to the steady state shear stress.We can assume that a stress growth curve with an overshoot points out to thixotropic behavior.After the steady state shear stress is reached,the shear deformation is stopped,and the stress relaxation begins.It is to be expected that the shear stress will recover after the stress relaxation.Systems with shear thinning and plastic flow behavior were examined.The thixotropy is discussed in relation to the flow behavior.Stress growth experiments were performed with shear rates from the first Newtonian region and from the shear thinning region of the systems with shear thinning flow behavior.Stress start-up experiments were carrying out with shear rates from the first and second yield stress regions and from the transition section of a system with plastic flow behavior.
基金National Natural Science Foundation of China (Grant Nos. 61503214, 61573215).
文摘Dear editor, In certain practical systems, quantized control can effectively solve stabilization problems in intelligent transportation systems and digital systems [1]. Constant progress has been made on linear quantization systems. The problems of input quantization and output quantization were studied in [2] for the class of linear systems using a logarithmic quantizer, and the problem of quadratic stabilization was addressed by a proposed condition. On the contrary, research on nonlinear quantization systems is very significant and certain researches for nonlinear quantization systems are available [3,4].
基金the Russian Foundation for Basic Research (grant 16-04-01376).
文摘In a study of gerbils with contrasting social and mating systems (group-living monogamous Mongolian gerbil Meriones unguiculatus, solitary nonterritorial promiscuous midday jird M. meridianus, and solitary territorial promiscuous pale gerbil Gerbillus perpallidus), we employed part ner pref ere nee tests (PPTs) to assess among-species variation in sociability and pair-bonding patterns and tested whether the nature of contact between individuals: direct contact (DC) versus nondirect contact (NDC) affected our results. We measured male pref ere nces as the time: 1) spe nt alone, 2) with familiar (partner), and 3) unfamiliar (stranger) female in the 3-chambered apparatus. Gerbil species differed strongly in sociability and male partner preferences. The time spent alone was a reliable indicator of species sociability indepe ndent of the nature of con tact, whereas the pattern and level of betwee n-species differe nces in male partner preferences depended on con tact type: DC PPTs, un like NDC-tests, discriminated well betwee n monogamous and promiscuous species. In the DC-tests, stranger-directed aggression and stranger avoidanee were observed both in the highly social monogamous M. unguiculatus and the solitary territorial promiscuous G. perpallidus, but not in the non territorial promiscuous M. meridianus. In M. unguiculatus, stranger avoidanee in the DC-tests increased the time spent with the partner, thus providing evidence of a partner preference that was not found in the NDC-tests, whereas in G. perpallidus, stran ger avoidance in creased the time spe nt alone. This first comparative experimental study of partner prefere nces in gerbils provides new in sights into the in terspecific variation in gerbil sociality and mating systems and sheds light on behavioral mechanisms un derlyi ng social fidelity and pair-b on ding.
基金supported by the National Natural Science Foundation of China(61304094,61673198,61773187)the Natural Science Foundation of Liaoning Province,China(20180520009).
文摘This study explores a stable model order reduction method for fractional-order systems. Using the unsymmetric Lanczos algorithm, the reduced order system with a certain number of matched moments is generated. To obtain a stable reduced order system, the stable model order reduction procedure is discussed. By the revised operation on the tridiagonal matrix produced by the unsymmetric Lanczos algorithm, we propose a reduced order modeling method for a fractional-order system to achieve a satisfactory fitting effect with the original system by the matched moments in the frequency domain. Besides, the bound function of the order reduction error is offered. Two numerical examples are presented to illustrate the effectiveness of the proposed method.
文摘The growth of environmental energy harvesting has been explosive in wireless computing systems especially when replacing or recharging batteries manually is impracticable.This work investigates the scheduling of periodic weekly hard real-time tasks under energy constraints.Based on this motivation,we proposed a real-time scheduling algorithm,namely energy guarantee dynamic voltage and frequency scaling(EG-DVFS),that utilizes the earliest deadline-harvesting(ED-H)scheduling algorithm combined with dynamic voltage and frequency scaling.This one is qualified as real-time since tasks must satisfy their timing constraints.We assume that the preemptable tasks receive dynamic priorities according to the earliest deadline first(EDF)rule.EG-DVFS adjusts the processor's behavior by characterizing the properties of the energy source module,capacity of the stored energy as well as the harvested energy in a future duration.Specifically,tasks are executed at full processor speed if the amount of energy in the battery is enough to finish its execution.Otherwise,the processor slows down task execution to the lowest possible processor speed while still guaranteeing to meet all the timing constraints.EG-DVFS mainly depends on the on-line computation of the slack time and the slack energy with dynamic voltage and frequency selection in order to achieve an improved system performance.Experimental results show that EG-DVFS can achieve capacity savings up of up to 33%when compared to ED-H.
文摘As a continuation of last four years’ special sections on software systems, this special section encourages and promotes research to address challenges from the perspective of software systems. The goal of this special section is to present state-of-the-art and high-quality original research in the area of software systems. Different from previous special sections, this special section includes two different major themes: 1) Internetware and Beyond;2) Trustworthy Computing Systems and Networks.
基金the Australian Research Council (ARC)(No. DP-160104500)Data61-CSIRO. Australia. This work was also supported in part by the European Research Council (No. ERC-CoG-771687)the Netherlands Organization for Scientific Research (No. NWO-vidi-14134).
文摘Abs tract: A fundamental aspect of society is the exchange and discussion of opinions bet ween individuals, occurring in situations as varied as company boardrooms, eleme nt ary school classrooms and online social media. After a very brief introduction to the established results of the most fundamental opinion dynamics models, which seek to mathematically capture observed social phenomena, a brief discussion follows on several recent themes pursued by the authors building on the fundamental ideas. In the first theme, we study the way an individuaFs self-confidence can develop through contributing to discussions on a sequence of topics, reaching a consensus in each case, where the consensus value to some degree reflects the contribution of that individual to the conclusion. During this process, the individuals in the network and the way they interact can change. The second theme introduces a novel discrete-time model of opinion dynamics to study how discrepancies between an individual's expressed and private opinions can arise due to stubbornness and a pressure to conform to a social norm. It is also shown that a few extremists can create "pluralistic ignorance^^, where people believe there is majority support for a position but in fact the position is privately rejected by the majority. Last, we consider a group of individuals discussing a collection of logically related topics. In particular, we identify that for topics whose logical interdependencies take on a cascade structure, disagreement in opinions can occur if individuals have competing and/or heterogeneous views on how the topics are related, i.e., the logical interdependence structure varies between individuals.
基金This paper has been supported by Korea Evaluation Institute of Industrial Technology (KEIT) in the smart factory R&D program of KEIT (10054495, Development of data collection processing systems capable of adapting manufacturing environment and building a site for demonstration).
文摘A simulation model enables manufacturers to accurately evaluate the performance of their manufacturing systems.A vital input to build simulation models of manufacturing systems is the system behaviour,which is modelled based on extensive data on manufacturing systems and their elements.However,for outsourced manufacturing systems,data provided from external suppliers to manufacturers are generally limited and insufficient.Therefore,a solution is required to identify and secure system behaviour from available data.We propose herein a behaviour extraction process along with detailed activities and diagrams to extract system behaviour from limited data.By using the systems engineering standard ANSI/EIA-632,the proposed process systematically restructures available data on a manufacturing system and its elements and then provides complete system behaviour to build a simulation model.A case study on a cooling water control system in a hot strip mill convincingly demonstrates the applicability and effectiveness of the proposed process.
文摘The objective of this paper is to propose a reduced-order observer for a class of Lipschitz nonlinear discrete-time systems.The conditions that guarantee the existence of this observer are presented in the form of linear matrix inequalities(LMIs). To handle the Lipschitz nonlinearities, the Lipschitz condition and the Young′s relation are adequately operated to add more degrees of freedom to the proposed LMI. Necessary and sufficient conditions for the existence of the unbiased reduced-order observer are given. An extension to H_∞ performance analysis is considered in order to deal with H_∞ asymptotic stability of the estimation error in the presence of disturbances that affect the state of the system. To highlight the effectiveness of the proposed design methodology, three numerical examples are considered. Then, high performances are shown through real time implementation using the ARDUINO MEGA 2560 device.
基金supported by National Natural Science Foundation of China(Grant Nos.71571001,71873002)Natural Science Foundation of Universities of Anhui Province(Grant No.KJ2018A0119)Promoting Plan of Higher Education of Anhui Province(Grant No.TSKJ2016B11).
文摘This paper reports the boundedness and stability of highly nonlinear hybrid neutral stochastic differential delay equations(NSDDEs) with multiple delays. Without imposing linear growth condition, the boundedness and exponential stability of the exact solution are investigated by Lyapunov functional method.In particular, using the M-matrix technique, the mean square exponential stability is obtained. Finally, three examples are presented to verify our results.
基金NSFC (Grant Nos. 11131001, 11371124 and 11401186).
文摘In this paper we study the saturated fusion systems over a direct product of the extraspecial group of order p^3 of exponent p and a finite abelian p-group. The result provides some new exotic fusion systems, whose unique components are isomorphic to the exotic fusion systems over 7+^1+2 found by Ruiz and Viruel.
基金This work was supported by National Natural Science Foundation of China(Grant Nos.61622304,61773201)Natural Science Foundation of Jiangsu Province(Grant No.BK20160035)and Fundamental Research Funds for the Central Universities(Grant Nos.NE2014202,NE2015002).
文摘This paper addresses the stability problem associated with a class of sw计ched positive nonlinear systems in which each vector field is homogeneous,cooperative,and irreducible.Instead of using the Lyapunov function approach,we fully establish the invariant ray analysis method to establish several stability conditions that depend on the states,rays,and/or times.We illustrate the efficiency of our proposed approach using the example of a chemical reaction.
文摘Asymptotic stability of nonlinear fractional order affine systems with bounded inputs is dealt.The main contribution is to design a new bounded fractional order chattering free sliding mode controller in which the system states converge to the sliding surface at a determined finite time.To eliminate the chattering in the sliding mode and make the input controller bounded,hyperbolic tangent is used for designing the proposed fractional order sliding surface.Finally,the stability of the closed loop system using this bounded sliding mode controller is guaranteed by Lyapunov theory.A comparison with the integer order case is then presented and fractional order nonlinear polynomial systems are also studied as the special case.Finally,simulation results are provided to show the effectiveness of the designed controller.
基金supported by the Natural Sciences and Engineering Research Council of Canada(NSERC).
文摘State convergence is a novel control algorithm for bilateral teleoperation of robotic systems. First, it models the teleoperation system on state space and considers all the possible interactions between the master and slave systems. Second, it presents an elegant design procedure which requires a set of equations to be solved in order to compute the control gains of the bilateral loop. These design conditions are obtained by turning the master-slave error into an autonomous system and imposing the desired dynamic behavior of the teleoperation system. Resultantly, the convergence of master and slave states is achieved in a well-defined manner. The present study aims at achieving a similar convergence behavior offered by state convergence controller while reducing the number of variables sent across the communication channel. The proposal suggests transmitting composite master and slave variables instead of full master and slave states while keeping the operator's force channel intact. We show that,with these composite and force variables;it is indeed possible to achieve the convergence of states in a desired way by strictly following the method of state convergence. The proposal leads to a reduced complexity state convergence algorithm which is termed as composite state convergence controller. In order to validate the proposed scheme in the absence and presence of communication time delays, MATLAB simulations and semi-real time experiments are performed on a single degree-of-freedom teleoperation system.
文摘A.Submission The Journal publishes papers that are addressed to the theory,methodology and applications relating to systems science and systems engineering.All papers relating to these areas are welcome.1)Please email your manuscript in.doc or.pdf format to jssse@mail.tsinghua.edu.cn for the reviewing process.The manuscript should be complete,including all tables and illustrations,and be prepared in the style described below.2)The manuscript should be double-blind,which means(a)all authors5 names and institutions must be removed,(b)all acknowledgments in the text must be removed.
基金supported by the National Natural Science Foundation of China(61673045)the Fundamental Research Funds for the Central Universities(XK1802-4).
文摘Stochastic iterative learning control(ILC) is designed for solving the tracking problem of stochastic linear systems through fading channels. Consequently, the signals used in learning control algorithms are faded in the sense that a random variable is multiplied by the original signal. To achieve the tracking objective, a two-dimensional Kalman filtering method is used in this study to derive a learning gain matrix varying along both time and iteration axes. The learning gain matrix minimizes the trace of input error covariance. The asymptotic convergence of the generated input sequence to the desired input value is strictly proved in the mean-square sense. Both output and input fading are accounted for separately in turn, followed by a general formulation that both input and output fading coexists.Illustrative examples are provided to verify the effectiveness of the proposed schemes.
文摘This paper presents a new Long-range generalized predictive controller in the synchronous reference frame for a wind energy system doubly-fed induction generator based. This controller uses the state space equations that consider the rotor current and voltage as state and control variables, to execute the predictive control action. Therefore, the model of the plant must be transformed into two discrete transference functions, by means of an auto-regressive moving average model, in order to attain a discrete and decoupled controller, which makes it possible to treat it as two independent single-input single-output systems instead of a magnetic coupled multiple-input multiple-output system. For achieving that, a direct power control strategy is used, based on the past and future rotor currents and voltages estimation. The algorithm evaluates the rotor current predictors for a defined prediction horizon and computes the new rotor voltages that must be injected to controlling the stator active and reactive powers. To evaluate the controller performance, some simulations were made using Matlab/Simulink. Experimental tests were carried out with a small-scale prototype assuming normal operating conditions with constant and variable wind speed profiles. Finally, some conclusions respect to the dynamic performance of this new controller are summarized.