The real-time risk-averse dispatch problem of an integrated electricity and natural gas system(IEGS)is studied in this paper.It is formulated as a real-time conditional value-at-risk(CVaR)-based risk-averse dis-patch ...The real-time risk-averse dispatch problem of an integrated electricity and natural gas system(IEGS)is studied in this paper.It is formulated as a real-time conditional value-at-risk(CVaR)-based risk-averse dis-patch model in the Markov decision process framework.Because of its stochasticity,nonconvexity and nonlinearity,the model is difficult to analyze by traditional algorithms in an acceptable time.To address this non-deterministic polynomial-hard problem,a CVaR-based lookup-table approximate dynamic programming(CVaR-ADP)algo-rithm is proposed,and the risk-averse dispatch problem is decoupled into a series of tractable subproblems.The line pack is used as the state variable to describe the impact of one period’s decision on the future.This facilitates the reduction of load shedding and wind power curtailment.Through the proposed method,real-time decisions can be made according to the current information,while the value functions can be used to overview the whole opti-mization horizon to balance the current cost and future risk loss.Numerical simulations indicate that the pro-posed method can effectively measure and control the risk costs in extreme scenarios.Moreover,the decisions can be made within 10 s,which meets the requirement of the real-time dispatch of an IEGS.Index Terms—Integrated electricity and natural gas system,approximate dynamic programming,real-time dispatch,risk-averse,conditional value-at-risk.展开更多
Assessment of the current status of Lake Baikal proved to be based on changes in natural (“preindustrial”) chemical content in basic abiotic and biological compartments of the Lake geosystem. This approach was used ...Assessment of the current status of Lake Baikal proved to be based on changes in natural (“preindustrial”) chemical content in basic abiotic and biological compartments of the Lake geosystem. This approach was used to evaluate background “base-line levels” of 6 major and about 50 minor and trace ele-ments in the Lake Baikal water body using a number of most reliable data re-ported within 1992-2012. In terms of environment geochemistry Baikal is one of the purest water reservoirs on the Earth. A simple mass balance model was proposed for assessing possible anthropogenic impact on Baikal water geo-chemistry. Estimations of change trends showed that only for Na+, SO42-, Cl- and Mo growth rate of their average concentrations in the Lake occurred to be 1%, 3%, 7% and 2% in every 10 years. Space-time monitoring schedules for all water body compartments of the Lake are proposed as well as similar moni-toring programs for tributaries, precipitations, bottom sediments, aquatic biota.展开更多
This paper presents a new architecture of a graphics system for microkernel operating systems,including real-time operating systems.The following major parts of the architecture are presented:a user-level subsystem re...This paper presents a new architecture of a graphics system for microkernel operating systems,including real-time operating systems.The following major parts of the architecture are presented:a user-level subsystem responsible for interaction with user applications;a bottom-level subsystem providing the functionality for graphics drivers,such as managing graphics output,video memory management,etc.;a kernel-level subsystem providing interaction with the kernel,and performing low-level operations,such as working with physical memory,processes,etc.The mechanisms of interaction of user applications with the user level of the graphics system,as well as interaction of the different levels of the graphics subsystem are presented.The paper pays much attention to various approaches to testing:the use of unit testing,testing using hardware and software emulators.Another important characteristic of a graphics system is its performance,in particular the performance of low-level operations such as memory allocation:the developed architecture suggests using a separate memory allocator which is faster than standard memory allocation functions.Comparison of the performances of graphics system implementation for microkernel real-time operating system and graphics server Xorg is presented,showing significant superiority of the proposed architecture in a number of work scenarios.展开更多
基金supported by State Key Laboratory of HVDC under Grant SKLHVDC-2021-KF-09.
文摘The real-time risk-averse dispatch problem of an integrated electricity and natural gas system(IEGS)is studied in this paper.It is formulated as a real-time conditional value-at-risk(CVaR)-based risk-averse dis-patch model in the Markov decision process framework.Because of its stochasticity,nonconvexity and nonlinearity,the model is difficult to analyze by traditional algorithms in an acceptable time.To address this non-deterministic polynomial-hard problem,a CVaR-based lookup-table approximate dynamic programming(CVaR-ADP)algo-rithm is proposed,and the risk-averse dispatch problem is decoupled into a series of tractable subproblems.The line pack is used as the state variable to describe the impact of one period’s decision on the future.This facilitates the reduction of load shedding and wind power curtailment.Through the proposed method,real-time decisions can be made according to the current information,while the value functions can be used to overview the whole opti-mization horizon to balance the current cost and future risk loss.Numerical simulations indicate that the pro-posed method can effectively measure and control the risk costs in extreme scenarios.Moreover,the decisions can be made within 10 s,which meets the requirement of the real-time dispatch of an IEGS.Index Terms—Integrated electricity and natural gas system,approximate dynamic programming,real-time dispatch,risk-averse,conditional value-at-risk.
文摘Assessment of the current status of Lake Baikal proved to be based on changes in natural (“preindustrial”) chemical content in basic abiotic and biological compartments of the Lake geosystem. This approach was used to evaluate background “base-line levels” of 6 major and about 50 minor and trace ele-ments in the Lake Baikal water body using a number of most reliable data re-ported within 1992-2012. In terms of environment geochemistry Baikal is one of the purest water reservoirs on the Earth. A simple mass balance model was proposed for assessing possible anthropogenic impact on Baikal water geo-chemistry. Estimations of change trends showed that only for Na+, SO42-, Cl- and Mo growth rate of their average concentrations in the Lake occurred to be 1%, 3%, 7% and 2% in every 10 years. Space-time monitoring schedules for all water body compartments of the Lake are proposed as well as similar moni-toring programs for tributaries, precipitations, bottom sediments, aquatic biota.
基金This work was supported by SRISA RAS fundamental scientific research 47 GP(No.FNEF-2022-0022).
文摘This paper presents a new architecture of a graphics system for microkernel operating systems,including real-time operating systems.The following major parts of the architecture are presented:a user-level subsystem responsible for interaction with user applications;a bottom-level subsystem providing the functionality for graphics drivers,such as managing graphics output,video memory management,etc.;a kernel-level subsystem providing interaction with the kernel,and performing low-level operations,such as working with physical memory,processes,etc.The mechanisms of interaction of user applications with the user level of the graphics system,as well as interaction of the different levels of the graphics subsystem are presented.The paper pays much attention to various approaches to testing:the use of unit testing,testing using hardware and software emulators.Another important characteristic of a graphics system is its performance,in particular the performance of low-level operations such as memory allocation:the developed architecture suggests using a separate memory allocator which is faster than standard memory allocation functions.Comparison of the performances of graphics system implementation for microkernel real-time operating system and graphics server Xorg is presented,showing significant superiority of the proposed architecture in a number of work scenarios.
