With the rapid integration of renewable energy sources,modern power systems are increasingly challenged by heightened volatility and uncertainty.Doubly-fed variable-speed pumped storage units(DFVS-PSUs)have emerged as...With the rapid integration of renewable energy sources,modern power systems are increasingly challenged by heightened volatility and uncertainty.Doubly-fed variable-speed pumped storage units(DFVS-PSUs)have emerged as promising technologies for mitigating grid oscillations and enhancing system flexibility.However,the excitation converters in DFVS-PSUs are prone to significant issues such as elevated common-mode voltage(CMV)and neutral-point voltage(NPV)fluctuations,which can lead to electromagnetic interference and degrade transient performance.To address these challenges,an optimized virtual space vector pulse width modulation(OVSVPWM)strategy is proposed,aiming to suppress CMV and NPV simultaneously through coordinated multi-objective control.Specifically,a dynamic feedback mechanism is introduced to adjust the balancing factor of basic vectors in the synthesized virtual small vector in real-time,achieving autonomous balancing of the NPV.To address the excessive switching actions introduced by the OVSVPWM strategy,a phase duty ratio-based sequence reconstruction method is adopted,which reduces the total number of switching actions to half of the original.A zero-level buffering scheme is employed to reconstruct the single-phase voltage-level output sequence,achieving peak CMV suppression down to udc/6.Simulation results demonstrate that the proposed strategy significantly improves electromagnetic compatibility and operational stability while maintaining high power quality.展开更多
In this paper,we establish some strong laws of large numbers,which are for nonindependent random variables under the framework of sublinear expectations.One of our main results is for blockwise m-dependent random vari...In this paper,we establish some strong laws of large numbers,which are for nonindependent random variables under the framework of sublinear expectations.One of our main results is for blockwise m-dependent random variables,and another is for sub-orthogonal random variables.Both extend the strong law of large numbers for independent random variables under sublinear expectations to the non-independent case.展开更多
The Private Sector Promotion Law is formulated in the background of an increasingly mature market mechanism and a gradually optimized business environment,thus bearing a strong hallmark of the times.The rule of law va...The Private Sector Promotion Law is formulated in the background of an increasingly mature market mechanism and a gradually optimized business environment,thus bearing a strong hallmark of the times.The rule of law values embedded in it also exhibit a distinct perspective aligned with the current era.In the context of Chinese modernization,the Private Sector Promotion Law takes reform and opening-up as its core theme and aims for full and balanced economic development.It focuses on the development of new quality productive forces and the empowerment of big data,with a key emphasis on highlighting Chinese characteristics in economic development.Meanwhile,the Private Sector Promotion Law demonstrates the rule of law values that balance public and private law dimensions.On the one hand,it encourages market participants to engage in fair competition,pursue independent development,operate with integrity,and assume the corresponding social responsibilities.On the other hand,it requires public authority entities to treat every market participant equally.They should provide the necessary support and guidance through means such as administrative payment and administrative guidance and adopt a restrained attitude in the application of administrative penalties,thereby safeguarding the legitimate rights and interests of market participants.展开更多
International investment constitutes a key dimension of high-quality cooperation under the Belt and Road Initiative.However,affected by unilateralism,protectionist measures,and growing regulatory uncertainty,it faces ...International investment constitutes a key dimension of high-quality cooperation under the Belt and Road Initiative.However,affected by unilateralism,protectionist measures,and growing regulatory uncertainty,it faces increasingly complex and diverse risks.Deepening the rule of law cooperation based on an international order governed by international law is not only a fundamental way to mitigate investment risks associated with the Belt and Road Initiative but also an essential requirement for building a more just and reasonable system of global economic governance.At present,investment rule of law cooperation under the Belt and Road Initiative faces three main challenges:limited legal cooperation capacity among some participating countries at the subject level,insufficient coordination between hard law and soft law at the normative level,and relatively weak regional enforcement and dispute-prevention mechanisms at the implementation level.To advance regional investment rule of law cooperation and promote the high-quality development of the Belt and Road Initiative,China should foster consultative governance on investment rule of law cooperation among partner countries,comprehensively upgrade hard law and soft law instruments regulating investment,and strengthen enforcement and dispute settlement capacity,thereby contributing a more just,reasonable,and inclusive model of investment governance to the world.展开更多
As a crucial aspect of international governance,international standardization requires legitimacy grounded in the principles and frameworks established by international law.Building upon an understanding of the common...As a crucial aspect of international governance,international standardization requires legitimacy grounded in the principles and frameworks established by international law.Building upon an understanding of the commonalities between international law and international standardization,this paper explores the mechanism through which international law centered on treaties empowers international standardization.展开更多
The capture zones of the continuous and pulsed guidance laws in the pursuit-evasion game are analytically discussed in this paper to provide deep insights into the capturability distinction between the continuous guid...The capture zones of the continuous and pulsed guidance laws in the pursuit-evasion game are analytically discussed in this paper to provide deep insights into the capturability distinction between the continuous guidance law and the pulsed guidance law.Specifically,first,in the pursuit-evasion game,various capture cases are defined regarding the Zero-Effort Miss distance(ZEM)to facilitate the capturability analysis.Then,for both the evader and the pursuer,the Linear-Quadratic Differential Game(LQDG)guidance laws concerning the continuous acceleration and the pulsed acceleration are converted into a unified form.In each capture case,the optimal solution existence conditions are derived,and the corresponding capture zones are formulated.The discussion on the capture zones shows that if the optimal solution exists,the distinction between the pulsed guidance law and the continuous guidance law can be neglected under small guidance effort weight.However,the capture zone of the continuous guidance law is larger than that of the pulsed guidance law with large pursuer guidance effort weight,but smaller with large evader guidance effort weight.Finally,various simulations are conducted to illustrate the distinction of the continuous and pulsed guidance laws,as well as the impact of the acceleration ratio and the time constant ratio on the capturability.展开更多
The International Tribunal for the Law of the Sea(ITLOS)is requested to provide an advisory opinion on the specific obligations of states parties regarding climate change under the United Nations Convention on the Law...The International Tribunal for the Law of the Sea(ITLOS)is requested to provide an advisory opinion on the specific obligations of states parties regarding climate change under the United Nations Convention on the Law of the Sea(UNCLOS).This opinion recognizes that greenhouse gas emissions constitute pollution of the marine environment and emphasizes the necessity for states to take measures to mitigate such pollution.Legally,this opinion clarifies the necessity of collective action in addressing climate change,thereby advancing the concept of climate justice.However,the advisory opinions serve merely as'primary rules',failing to elaborate on how to demonstrate the causal link between mitigation actions and the harm suffered by other states,as well as the manner in which state responsibility for climate-induced loss and damage should be borne.Divergent views among states regarding the classification of greenhouse gases as pollutants highlight the complexities and uncertainties of climate policy.To promote compatibility between climate law and maritime law,this article argues that ITLOS should prioritize the establishment of an'assistance-based'loss and damage compensation mechanism.This mechanism aims to support developing states severely affected by climate change through collective international efforts rather than solely through compensation.Furthermore,the advisory opinion is expected to play a crucial role in protecting marine environments and addressing climate change,to further clarify the duty of care that states must exercise in climate governance.展开更多
In the energy regulation based varibable-speed electrohydraulic drive system, the supply energy and the demanded energy, which will affect the control performance greatly, are crucial. However, they are hard to be obt...In the energy regulation based varibable-speed electrohydraulic drive system, the supply energy and the demanded energy, which will affect the control performance greatly, are crucial. However, they are hard to be obtained via conventional methods for some reasons. This paper tries to a new route： the definitive numerical values of the supply energy and the demanded energy are not required, except for their relationship which is called energy state. A three-layer back propagation（BP） neural network was built up to act as an energy analysis unit to deduce the energy state. The neural network has three inputs： the reference displacement, the actual displacement of cylinder rod and the system flowrate supply. The output of the neural network is energy state. A Chebyshev type II filter was designed to calculate the cylinder speed for the estimation of system flowrate supply. The training and testing samples of neural network were collected by the system accurate simulation model. After off-line training, the neural network was tested by the testing data. And the testing result demonstrates that the designed neural network was successful. Then, the neural network acts as the energy analysis unit in real-time experiments of cylinder position control, where it works efficiently under square-wave and sine-wave reference displacement. The experimental results validate its feasibility and adaptability. Only a position sensor and some pressure sensors, which are cheap and have quick dynamic response, are necessary for the system control. And the neural network plays the role of identifying the energy state.展开更多
In general,Variable-Speed Constant Frequency (VSCF)Wind generation system is controlled by stator voltage orientation method which based on the mathematic model of VSCF Wind generation system and discussed the control...In general,Variable-Speed Constant Frequency (VSCF)Wind generation system is controlled by stator voltage orientation method which based on the mathematic model of VSCF Wind generation system and discussed the control strategy.Present the whole dynamic control model of variable-speed wind generator system in MATLAB/ Simulink,and the simulation results confirm the validity and effectiveness of the proposed control strategy.展开更多
Nonlinear controllability and attitude stabilization are studied for the underactuated nonholonomic dynamics of a rigid spacecraft with one variable-speed control moment gyro （VSCMG）, which supplies only two interna...Nonlinear controllability and attitude stabilization are studied for the underactuated nonholonomic dynamics of a rigid spacecraft with one variable-speed control moment gyro （VSCMG）, which supplies only two internal torques. Nonlinear controllability theory is used to show that the dynamics are locally controllable from the equilibrium point and thus can be asymptotically stabilized to the equilibrium point via time-invariant piecewise continuous feedback laws or time-periodic continuous feedback laws. Specifically, when the total angular momentum of the spacecraft-VSCMG system is zero, any orientation can be a controllable equilib- rium attitude. In this case, the attitude stabilization problem is addressed by designing a kinematic stabilizing law, which is implemented through a nonlinear proportional and deriva- tive controller, using the generalized dynamic inverse （GDI） method. The steady-state instability inherent in the GDI con- troller is elegantly avoided by appropriately choosing control gains. In order to obtain the command gimbal rate and wheel acceleration from control torques, a simple steering logic is constructed to accommodate the requirements of attitude sta- bilization and singularity avoidance of the VSCMG. Illustrative numerical examples verify the efficacy of the proposed control strategy.展开更多
In this paper, the problem of coplanar variable-speed interception between a tactical missile and an aircraft is analysed by using the differential games theory. A unified approximate guidance law in feedback form is ...In this paper, the problem of coplanar variable-speed interception between a tactical missile and an aircraft is analysed by using the differential games theory. A unified approximate guidance law in feedback form is obtained by using the technique of forced singular perturbation (FSPT). The illustrative example with the realistic aerodynamic and propulsion data shows that this suboptimal guidance control law is available for the practical applications.展开更多
The method of integrating factors is used to study the conservation laws of the Herglotz type Birkhoffian systems in this paper.Firstly,the definition of the integrating factors of the Herglotz type Birkhoffian system...The method of integrating factors is used to study the conservation laws of the Herglotz type Birkhoffian systems in this paper.Firstly,the definition of the integrating factors of the Herglotz type Birkhoffian systems is given.Secondly,the relationship between the integrating factors and conservation laws is studied,and the conservation theorems of Herglotz type Birkhoff's equations and their inverse theorems are established.Thirdly,two types of generalized Killing equations for calculating integrating factors are given.Finally,as an example,a linear damped oscillator is taken.This example can be transformed into a Herglotz type Birkhoffian system.The resulting conservation theorems are used to find the conserved quantities for this example.展开更多
This work focuses on a Keller-Segel chemotaxis model, with an emphasis on its conservation laws. Through a new approach combined with the multiplier method, called the mixed method, we obtain conservation vectors that...This work focuses on a Keller-Segel chemotaxis model, with an emphasis on its conservation laws. Through a new approach combined with the multiplier method, called the mixed method, we obtain conservation vectors that are related and unrelated to symmetric information. In addition, some exact solutions with particular forms are obtained according to the method of conservation laws. These particular solutions are different from the group-invariant solutions.展开更多
There is a wide recognition that encompassing an obligation of good faith in every commercial contract is one of the most important advances in contract law in the twentieth century^([1]).Despite the fact that this co...There is a wide recognition that encompassing an obligation of good faith in every commercial contract is one of the most important advances in contract law in the twentieth century^([1]).Despite the fact that this concept has been incorporated in the vast majority of national legal systems,its precise scope and application may vary from one to another,depending on the commercial traditions and customs of each legal system^([2]).The fact that good faith has been treated differently in different national legal systems has also been reflected on the international level through its inclusion in international legal instruments,one of which is the United Nations Convention on Contracts for the International Sale of Goods(hereafter CISG).In this article,the legislative history of the CISG will be closely examined with the purpose of finding out how a compromise was reached between the common law countries,which expressly objected to the imposition of a duty of good faith,and the civil law countries,which explicitly endorse its incorporation.A logical result flowing from this historical examination,as will be submitted,is that the conceptual ambiguity of good faith is the underlying reasoning behind their fundamentally different attitudes towards the incorporation of this notion in the international commercial context.展开更多
It is shown that time asymmetry is essential for deriving thermodynamic law and arises from the turnover of energy while reducing its information content and driving entropy increase. A dynamically interpreted princip...It is shown that time asymmetry is essential for deriving thermodynamic law and arises from the turnover of energy while reducing its information content and driving entropy increase. A dynamically interpreted principle of least action enables time asymmetry and time flow as a generation of action and redefines useful energy as an information system which implements a form of acting information. This is demonstrated using a basic formula, originally applied for time symmetry/energy conservation considerations, relating time asymmetry (which is conventionally denied but here expressly allowed), to energy behaviour. The results derived then explained that a dynamic energy is driving time asymmetry. It is doing it by decreasing the information content of useful energy, thus generating action and entropy increase, explaining action-time as an information phenomenon. Thermodynamic laws follow directly. The formalism derived readily explains what energy is, why it is conserved (1st law of thermodynamics), why entropy increases (2nd law) and that maximum entropy production within the restraints of the system controls self-organized processes of non-linear irreversible thermodynamics. The general significance of the principle of least action arises from its role of controlling the action generating oriented time of nature. These results contrast with present understanding of time neutrality and clock-time, which are here considered a source of paradoxes, intellectual contradictions and dead-end roads in models explaining nature and the universe.展开更多
In this work,firstly the general definition of law and types of law are presented.Then general definition of justice and types of justice are explained.Constructional and/or complementary theories are defined as gener...In this work,firstly the general definition of law and types of law are presented.Then general definition of justice and types of justice are explained.Constructional and/or complementary theories are defined as general/specific,and interaction theories,relationship theories,and hybrid theories are specifically mentioned.Accordingly,the interactions between the disciplines of law and justice are explained in more detail.Then,the general definition of engineering and philosophy of engineering are explained.The interactions between engineering and law are specifically evaluated,and interactions between engineering and 52 types of law are defined and case studies found in the literature are indicated for each.Then interactions between engineering and justice briefly mentioned.Relationships/interactions between engineering and 25 different types of justice discussed and evaluated with specific examples.Emphasis was placed on the historical development of the subject of philosophy in general,and philosophy of law was defined more specifically.Some of the philosophers of law and their areas of interest are presented in a table format and compared.The new perspective of philosophy was defined and the disciplines of R-Philosophy,R-Science,R-Justice,R-Law,R-Engineering,and R-Religion were expressed with the relevant basic concepts.New Era Philosophy,new and reconstructed Basic Philosophies,and Ideal Philosophical System explained generally.New perspective for the philosophy of justice is defined by considering the related new theories.Philosophy of defense,philosophy of equity,philosophy of equivalence,philosophy of judgment,philosophy of law,philosophy of protection,philosophy of punishment,and philosophy of rights are defined due to new perspective of philosophy.Also,philosophy of engineering law,philosophy of information technology law,philosophy of telecommunication law,and philosophy of security are defined by taking into account hybrid philosophies and general theories related to them.The interaction of engineering,law,justice,and basic philosophies has been generally expressed.展开更多
A shortage of courtrooms has long been a challenge in Malawi,especially since more judges were hired to help to streamline the country’s judicial process.Yet,while the current judiciary is headquartered in the countr...A shortage of courtrooms has long been a challenge in Malawi,especially since more judges were hired to help to streamline the country’s judicial process.Yet,while the current judiciary is headquartered in the country’s second-largest city of Blantyre,due to a lack of work space;some sections of the judiciary are located elsewhere,such as the juvenile,commercial and industrial courts.展开更多
Environmental rights are an important part of General Secretary Xi Jinping’s important discourses on respecting and protecting human rights.Soft law has played a significant role in the integrated development of the ...Environmental rights are an important part of General Secretary Xi Jinping’s important discourses on respecting and protecting human rights.Soft law has played a significant role in the integrated development of the theories of environmental rights and human rights.At the practical level,the soft law cooperation documents of the Belt and Road Initiative(BRI)have established general principles for the protection of environmental rights,policies for addressing climate change,standards for green investment and financing,and obligations for multinational corporations to protect the environment,making a contribution to the development and protection of environmental rights.In the future process of global environmental governance,it is necessary to start with the BRI’s soft law documents to further clarify the specific protection standards for environmental rights and promote the transformation of soft law into binding bilateral or multilateral agreements at the international level.In addition,it is essential to urge governments and enterprises to fulfill their due diligence obligations for environmental protection and strengthen information disclosure by emphasizing public interest responsibilities.Efforts should also be made to improve the environmental compliance systems of“going global”enterprises and enhance government supervision over corporate accountability for environmental rights.A corporate environmental protection accountability mechanism should be established,so as to actively promote global environmental governance in a more just and reasonable direction.展开更多
文摘With the rapid integration of renewable energy sources,modern power systems are increasingly challenged by heightened volatility and uncertainty.Doubly-fed variable-speed pumped storage units(DFVS-PSUs)have emerged as promising technologies for mitigating grid oscillations and enhancing system flexibility.However,the excitation converters in DFVS-PSUs are prone to significant issues such as elevated common-mode voltage(CMV)and neutral-point voltage(NPV)fluctuations,which can lead to electromagnetic interference and degrade transient performance.To address these challenges,an optimized virtual space vector pulse width modulation(OVSVPWM)strategy is proposed,aiming to suppress CMV and NPV simultaneously through coordinated multi-objective control.Specifically,a dynamic feedback mechanism is introduced to adjust the balancing factor of basic vectors in the synthesized virtual small vector in real-time,achieving autonomous balancing of the NPV.To address the excessive switching actions introduced by the OVSVPWM strategy,a phase duty ratio-based sequence reconstruction method is adopted,which reduces the total number of switching actions to half of the original.A zero-level buffering scheme is employed to reconstruct the single-phase voltage-level output sequence,achieving peak CMV suppression down to udc/6.Simulation results demonstrate that the proposed strategy significantly improves electromagnetic compatibility and operational stability while maintaining high power quality.
文摘In this paper,we establish some strong laws of large numbers,which are for nonindependent random variables under the framework of sublinear expectations.One of our main results is for blockwise m-dependent random variables,and another is for sub-orthogonal random variables.Both extend the strong law of large numbers for independent random variables under sublinear expectations to the non-independent case.
文摘The Private Sector Promotion Law is formulated in the background of an increasingly mature market mechanism and a gradually optimized business environment,thus bearing a strong hallmark of the times.The rule of law values embedded in it also exhibit a distinct perspective aligned with the current era.In the context of Chinese modernization,the Private Sector Promotion Law takes reform and opening-up as its core theme and aims for full and balanced economic development.It focuses on the development of new quality productive forces and the empowerment of big data,with a key emphasis on highlighting Chinese characteristics in economic development.Meanwhile,the Private Sector Promotion Law demonstrates the rule of law values that balance public and private law dimensions.On the one hand,it encourages market participants to engage in fair competition,pursue independent development,operate with integrity,and assume the corresponding social responsibilities.On the other hand,it requires public authority entities to treat every market participant equally.They should provide the necessary support and guidance through means such as administrative payment and administrative guidance and adopt a restrained attitude in the application of administrative penalties,thereby safeguarding the legitimate rights and interests of market participants.
基金funded by the National Social Science Fund of China(Grant No.20CFX083)。
文摘International investment constitutes a key dimension of high-quality cooperation under the Belt and Road Initiative.However,affected by unilateralism,protectionist measures,and growing regulatory uncertainty,it faces increasingly complex and diverse risks.Deepening the rule of law cooperation based on an international order governed by international law is not only a fundamental way to mitigate investment risks associated with the Belt and Road Initiative but also an essential requirement for building a more just and reasonable system of global economic governance.At present,investment rule of law cooperation under the Belt and Road Initiative faces three main challenges:limited legal cooperation capacity among some participating countries at the subject level,insufficient coordination between hard law and soft law at the normative level,and relatively weak regional enforcement and dispute-prevention mechanisms at the implementation level.To advance regional investment rule of law cooperation and promote the high-quality development of the Belt and Road Initiative,China should foster consultative governance on investment rule of law cooperation among partner countries,comprehensively upgrade hard law and soft law instruments regulating investment,and strengthen enforcement and dispute settlement capacity,thereby contributing a more just,reasonable,and inclusive model of investment governance to the world.
文摘As a crucial aspect of international governance,international standardization requires legitimacy grounded in the principles and frameworks established by international law.Building upon an understanding of the commonalities between international law and international standardization,this paper explores the mechanism through which international law centered on treaties empowers international standardization.
基金co-supported by the National Natural Science Foundation of China(Nos.U24B20157,62203031)the Natural Science Foundation of Beijing Municipality,China(No.4242041)+2 种基金the Natural Science Foundation of Zhejiang Province,China(No.LY24F030002)the Aeronautical ScienceFoundation of China(No.2024Z066051001)the Fundamental Research Funds for the Central Universities of China。
文摘The capture zones of the continuous and pulsed guidance laws in the pursuit-evasion game are analytically discussed in this paper to provide deep insights into the capturability distinction between the continuous guidance law and the pulsed guidance law.Specifically,first,in the pursuit-evasion game,various capture cases are defined regarding the Zero-Effort Miss distance(ZEM)to facilitate the capturability analysis.Then,for both the evader and the pursuer,the Linear-Quadratic Differential Game(LQDG)guidance laws concerning the continuous acceleration and the pulsed acceleration are converted into a unified form.In each capture case,the optimal solution existence conditions are derived,and the corresponding capture zones are formulated.The discussion on the capture zones shows that if the optimal solution exists,the distinction between the pulsed guidance law and the continuous guidance law can be neglected under small guidance effort weight.However,the capture zone of the continuous guidance law is larger than that of the pulsed guidance law with large pursuer guidance effort weight,but smaller with large evader guidance effort weight.Finally,various simulations are conducted to illustrate the distinction of the continuous and pulsed guidance laws,as well as the impact of the acceleration ratio and the time constant ratio on the capturability.
基金the National Social Science Fund Youth Project,entitled Research on the Integration of Global Carbon Market Rules Under the Glasgow Climate Agreement and China's Solutions(Grant Number:22CFX088).
文摘The International Tribunal for the Law of the Sea(ITLOS)is requested to provide an advisory opinion on the specific obligations of states parties regarding climate change under the United Nations Convention on the Law of the Sea(UNCLOS).This opinion recognizes that greenhouse gas emissions constitute pollution of the marine environment and emphasizes the necessity for states to take measures to mitigate such pollution.Legally,this opinion clarifies the necessity of collective action in addressing climate change,thereby advancing the concept of climate justice.However,the advisory opinions serve merely as'primary rules',failing to elaborate on how to demonstrate the causal link between mitigation actions and the harm suffered by other states,as well as the manner in which state responsibility for climate-induced loss and damage should be borne.Divergent views among states regarding the classification of greenhouse gases as pollutants highlight the complexities and uncertainties of climate policy.To promote compatibility between climate law and maritime law,this article argues that ITLOS should prioritize the establishment of an'assistance-based'loss and damage compensation mechanism.This mechanism aims to support developing states severely affected by climate change through collective international efforts rather than solely through compensation.Furthermore,the advisory opinion is expected to play a crucial role in protecting marine environments and addressing climate change,to further clarify the duty of care that states must exercise in climate governance.
基金supported by National Natural Science Foundation of China (Grant No. 50505042)
文摘In the energy regulation based varibable-speed electrohydraulic drive system, the supply energy and the demanded energy, which will affect the control performance greatly, are crucial. However, they are hard to be obtained via conventional methods for some reasons. This paper tries to a new route： the definitive numerical values of the supply energy and the demanded energy are not required, except for their relationship which is called energy state. A three-layer back propagation（BP） neural network was built up to act as an energy analysis unit to deduce the energy state. The neural network has three inputs： the reference displacement, the actual displacement of cylinder rod and the system flowrate supply. The output of the neural network is energy state. A Chebyshev type II filter was designed to calculate the cylinder speed for the estimation of system flowrate supply. The training and testing samples of neural network were collected by the system accurate simulation model. After off-line training, the neural network was tested by the testing data. And the testing result demonstrates that the designed neural network was successful. Then, the neural network acts as the energy analysis unit in real-time experiments of cylinder position control, where it works efficiently under square-wave and sine-wave reference displacement. The experimental results validate its feasibility and adaptability. Only a position sensor and some pressure sensors, which are cheap and have quick dynamic response, are necessary for the system control. And the neural network plays the role of identifying the energy state.
文摘In general,Variable-Speed Constant Frequency (VSCF)Wind generation system is controlled by stator voltage orientation method which based on the mathematic model of VSCF Wind generation system and discussed the control strategy.Present the whole dynamic control model of variable-speed wind generator system in MATLAB/ Simulink,and the simulation results confirm the validity and effectiveness of the proposed control strategy.
基金supported by the Innovation Foundation of BUAA for Ph.D Graduatesthe Innovation Foundation of the National Laboratory of Space Intelligent Control
文摘Nonlinear controllability and attitude stabilization are studied for the underactuated nonholonomic dynamics of a rigid spacecraft with one variable-speed control moment gyro （VSCMG）, which supplies only two internal torques. Nonlinear controllability theory is used to show that the dynamics are locally controllable from the equilibrium point and thus can be asymptotically stabilized to the equilibrium point via time-invariant piecewise continuous feedback laws or time-periodic continuous feedback laws. Specifically, when the total angular momentum of the spacecraft-VSCMG system is zero, any orientation can be a controllable equilib- rium attitude. In this case, the attitude stabilization problem is addressed by designing a kinematic stabilizing law, which is implemented through a nonlinear proportional and deriva- tive controller, using the generalized dynamic inverse （GDI） method. The steady-state instability inherent in the GDI con- troller is elegantly avoided by appropriately choosing control gains. In order to obtain the command gimbal rate and wheel acceleration from control torques, a simple steering logic is constructed to accommodate the requirements of attitude sta- bilization and singularity avoidance of the VSCMG. Illustrative numerical examples verify the efficacy of the proposed control strategy.
文摘In this paper, the problem of coplanar variable-speed interception between a tactical missile and an aircraft is analysed by using the differential games theory. A unified approximate guidance law in feedback form is obtained by using the technique of forced singular perturbation (FSPT). The illustrative example with the realistic aerodynamic and propulsion data shows that this suboptimal guidance control law is available for the practical applications.
基金Supported by the National Natural Science Foundation of China(12272248)。
文摘The method of integrating factors is used to study the conservation laws of the Herglotz type Birkhoffian systems in this paper.Firstly,the definition of the integrating factors of the Herglotz type Birkhoffian systems is given.Secondly,the relationship between the integrating factors and conservation laws is studied,and the conservation theorems of Herglotz type Birkhoff's equations and their inverse theorems are established.Thirdly,two types of generalized Killing equations for calculating integrating factors are given.Finally,as an example,a linear damped oscillator is taken.This example can be transformed into a Herglotz type Birkhoffian system.The resulting conservation theorems are used to find the conserved quantities for this example.
文摘This work focuses on a Keller-Segel chemotaxis model, with an emphasis on its conservation laws. Through a new approach combined with the multiplier method, called the mixed method, we obtain conservation vectors that are related and unrelated to symmetric information. In addition, some exact solutions with particular forms are obtained according to the method of conservation laws. These particular solutions are different from the group-invariant solutions.
文摘There is a wide recognition that encompassing an obligation of good faith in every commercial contract is one of the most important advances in contract law in the twentieth century^([1]).Despite the fact that this concept has been incorporated in the vast majority of national legal systems,its precise scope and application may vary from one to another,depending on the commercial traditions and customs of each legal system^([2]).The fact that good faith has been treated differently in different national legal systems has also been reflected on the international level through its inclusion in international legal instruments,one of which is the United Nations Convention on Contracts for the International Sale of Goods(hereafter CISG).In this article,the legislative history of the CISG will be closely examined with the purpose of finding out how a compromise was reached between the common law countries,which expressly objected to the imposition of a duty of good faith,and the civil law countries,which explicitly endorse its incorporation.A logical result flowing from this historical examination,as will be submitted,is that the conceptual ambiguity of good faith is the underlying reasoning behind their fundamentally different attitudes towards the incorporation of this notion in the international commercial context.
文摘It is shown that time asymmetry is essential for deriving thermodynamic law and arises from the turnover of energy while reducing its information content and driving entropy increase. A dynamically interpreted principle of least action enables time asymmetry and time flow as a generation of action and redefines useful energy as an information system which implements a form of acting information. This is demonstrated using a basic formula, originally applied for time symmetry/energy conservation considerations, relating time asymmetry (which is conventionally denied but here expressly allowed), to energy behaviour. The results derived then explained that a dynamic energy is driving time asymmetry. It is doing it by decreasing the information content of useful energy, thus generating action and entropy increase, explaining action-time as an information phenomenon. Thermodynamic laws follow directly. The formalism derived readily explains what energy is, why it is conserved (1st law of thermodynamics), why entropy increases (2nd law) and that maximum entropy production within the restraints of the system controls self-organized processes of non-linear irreversible thermodynamics. The general significance of the principle of least action arises from its role of controlling the action generating oriented time of nature. These results contrast with present understanding of time neutrality and clock-time, which are here considered a source of paradoxes, intellectual contradictions and dead-end roads in models explaining nature and the universe.
文摘In this work,firstly the general definition of law and types of law are presented.Then general definition of justice and types of justice are explained.Constructional and/or complementary theories are defined as general/specific,and interaction theories,relationship theories,and hybrid theories are specifically mentioned.Accordingly,the interactions between the disciplines of law and justice are explained in more detail.Then,the general definition of engineering and philosophy of engineering are explained.The interactions between engineering and law are specifically evaluated,and interactions between engineering and 52 types of law are defined and case studies found in the literature are indicated for each.Then interactions between engineering and justice briefly mentioned.Relationships/interactions between engineering and 25 different types of justice discussed and evaluated with specific examples.Emphasis was placed on the historical development of the subject of philosophy in general,and philosophy of law was defined more specifically.Some of the philosophers of law and their areas of interest are presented in a table format and compared.The new perspective of philosophy was defined and the disciplines of R-Philosophy,R-Science,R-Justice,R-Law,R-Engineering,and R-Religion were expressed with the relevant basic concepts.New Era Philosophy,new and reconstructed Basic Philosophies,and Ideal Philosophical System explained generally.New perspective for the philosophy of justice is defined by considering the related new theories.Philosophy of defense,philosophy of equity,philosophy of equivalence,philosophy of judgment,philosophy of law,philosophy of protection,philosophy of punishment,and philosophy of rights are defined due to new perspective of philosophy.Also,philosophy of engineering law,philosophy of information technology law,philosophy of telecommunication law,and philosophy of security are defined by taking into account hybrid philosophies and general theories related to them.The interaction of engineering,law,justice,and basic philosophies has been generally expressed.
文摘A shortage of courtrooms has long been a challenge in Malawi,especially since more judges were hired to help to streamline the country’s judicial process.Yet,while the current judiciary is headquartered in the country’s second-largest city of Blantyre,due to a lack of work space;some sections of the judiciary are located elsewhere,such as the juvenile,commercial and industrial courts.
文摘Environmental rights are an important part of General Secretary Xi Jinping’s important discourses on respecting and protecting human rights.Soft law has played a significant role in the integrated development of the theories of environmental rights and human rights.At the practical level,the soft law cooperation documents of the Belt and Road Initiative(BRI)have established general principles for the protection of environmental rights,policies for addressing climate change,standards for green investment and financing,and obligations for multinational corporations to protect the environment,making a contribution to the development and protection of environmental rights.In the future process of global environmental governance,it is necessary to start with the BRI’s soft law documents to further clarify the specific protection standards for environmental rights and promote the transformation of soft law into binding bilateral or multilateral agreements at the international level.In addition,it is essential to urge governments and enterprises to fulfill their due diligence obligations for environmental protection and strengthen information disclosure by emphasizing public interest responsibilities.Efforts should also be made to improve the environmental compliance systems of“going global”enterprises and enhance government supervision over corporate accountability for environmental rights.A corporate environmental protection accountability mechanism should be established,so as to actively promote global environmental governance in a more just and reasonable direction.
