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Effects of formal credit on pastoral household expense: Evidence from the Qinghai-Xizang Plateau of China
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作者 Yan Zhang Yi Huang +1 位作者 Fan Zhang Zeng Tang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第5期1774-1785,共12页
Formal credit is critical in agricultural production,allowing more expenditure and productive input,thereby improving farmers'welfare.In pastoral China,formal financial institutions are gradually increasing.Howeve... Formal credit is critical in agricultural production,allowing more expenditure and productive input,thereby improving farmers'welfare.In pastoral China,formal financial institutions are gradually increasing.However,a limited understanding remains of how formal credit affects herders'household expenses.Based on a survey of 544 herders from the Qinghai-Xizang Plateau of China,this study adopted the propensity score matching approach to identify the effect of formal credit on herders'total household expenses,daily expenses,and productive expenses.The results found that average age,grassland mortgage,and other variables significantly affected herders'participation in formal credit.Formal credit could significantly improve household expenses,especially productive expenses.A heterogeneity analysis showed that formal credit had a greater impact on the household total expense for those at higher levels of wealth;however,it significantly affected the productive expense of herders at lower wealth levels.Moreover,the mediating effect indicated that formal credit could affect herders'household income,thus influencing their household expenses.Finally,this study suggests that policies should improve herders'accessibility to formal credit. 展开更多
关键词 formal credit herders EXPENSE Qinghai-Xizang Plateau
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A Formal Model for Analyzing Fair Exchange Protocols Based on Event Logic
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作者 Ke Yang Meihua Xiao Zehuan Li 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2641-2663,共23页
Fair exchange protocols play a critical role in enabling two distrustful entities to conduct electronic data exchanges in a fair and secure manner.These protocols are widely used in electronic payment systems and elec... Fair exchange protocols play a critical role in enabling two distrustful entities to conduct electronic data exchanges in a fair and secure manner.These protocols are widely used in electronic payment systems and electronic contract signing,ensuring the reliability and security of network transactions.In order to address the limitations of current research methods and enhance the analytical capabilities for fair exchange protocols,this paper proposes a formal model for analyzing such protocols.The proposed model begins with a thorough analysis of fair exchange protocols,followed by the formal definition of fairness.This definition accurately captures the inherent requirements of fair exchange protocols.Building upon event logic,the model incorporates the time factor into predicates and introduces knowledge set axioms.This enhancement empowers the improved logic to effectively describe the state and knowledge of protocol participants at different time points,facilitating reasoning about their acquired knowledge.To maximize the intruder’s capabilities,channel errors are translated into the behaviors of the intruder.The participants are further categorized into honest participants and malicious participants,enabling a comprehensive evaluation of the intruder’s potential impact.By employing a typical fair exchange protocol as an illustrative example,this paper demonstrates the detailed steps of utilizing the proposed model for protocol analysis.The entire process of protocol execution under attack scenarios is presented,shedding light on the underlying reasons for the attacks and proposing corresponding countermeasures.The developedmodel enhances the ability to reason about and evaluate the security properties of fair exchange protocols,thereby contributing to the advancement of secure network transactions. 展开更多
关键词 Fair exchange protocols FAIRNESS formal analysis logic reasoning
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Fuzzy Set Approximations in Fuzzy Formal Contexts
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作者 Mingwen Shao Shiqing Fan 《南昌工程学院学报》 CAS 2006年第2期88-91,共4页
In this paper, a kind of multi-level formal concept is introduced. Based on the proposed multi-level formal concept,we present a pair of rough fuzzy set approximations within fuzzy formal contexts.By the proposed roug... In this paper, a kind of multi-level formal concept is introduced. Based on the proposed multi-level formal concept,we present a pair of rough fuzzy set approximations within fuzzy formal contexts.By the proposed rough fuzzy set approximations,we can approximate a fuzzy set according to different precision level.We discuss the properties of the proposed approximation operators in detail. 展开更多
关键词 Rough sets Concept lattices Approximation operators
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Formal Modeling of Self-Adaptive Resource Scheduling in Cloud
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作者 Atif Ishaq Khan Syed Asad Raza Kazmi Awais Qasim 《Computers, Materials & Continua》 SCIE EI 2023年第1期1183-1197,共15页
A self-adaptive resource provisioning on demand is a critical factor in cloud computing.The selection of accurate amount of resources at run time is not easy due to dynamic nature of requests.Therefore,a self-adaptive... A self-adaptive resource provisioning on demand is a critical factor in cloud computing.The selection of accurate amount of resources at run time is not easy due to dynamic nature of requests.Therefore,a self-adaptive strategy of resources is required to deal with dynamic nature of requests based on run time change in workload.In this paper we proposed a Cloud-based Adaptive Resource Scheduling Strategy(CARSS)Framework that formally addresses these issues and is more expressive than traditional approaches.The decision making in CARSS is based on more than one factors.TheMAPE-K based framework determines the state of the resources based on their current utilization.Timed-Arc Petri Net(TAPN)is used to model system formally and behaviour is expressed in TCTL,while TAPAAL model checker verifies the underline properties of the system. 展开更多
关键词 formal modeling MULTI-AGENT SELF-ADAPTIVE cloud computing
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Formal Verification Platform as a Service:WebAssembly Vulnerability Detection Application
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作者 LiangJun Deng Hang Lei +6 位作者 Zheng Yang WeiZhong Qian XiaoYu Li Hao Wu Sihao Deng RuChao Sha WeiDong Deng 《Computer Systems Science & Engineering》 SCIE EI 2023年第5期2155-2170,共16页
In order to realize a general-purpose automatic formal verification platform based on WebAssembly technology as a web service(FVPS),which aims to provide an automated report of vulnerability detections,this work build... In order to realize a general-purpose automatic formal verification platform based on WebAssembly technology as a web service(FVPS),which aims to provide an automated report of vulnerability detections,this work builds a Hyperledger Fabric blockchain runtime model.It proposes an optimized methodology of the functional equivalent translation from source program languages to formal languages.This methodology utilizes an external application programming interface(API)table to replace the source codes in compilation,thereby pruning the part of housekeeping codes to ease code inflation.Code inflation is a significant metric in formal language translation.Namely,minor code inflation enhances verification scale and performance efficiency.It determines the efficiency of formal verification,involving launching,running,and memory usage.For instance,path explosion increases exponentially,resulting in out-of-memory.The experimental results conclude that program languages like golang severely impact code inflation.FVPS reduces the wasm code size by over 90%,achieving two orders of optimization magnitude,from 2000 kilobyte(KB)to 90 KB.That means we can cope with golang applications up to 20 times larger than the original in scale.This work eliminates the gap between Hyperledger Fabric smart contracts and WebAssembly.Our approach is pragmatic,adaptable,extendable,and flexible.Nowadays,FVPS is successfully applied in a Railway-Port-Aviation blockchain transportation system. 展开更多
关键词 WebAssembly formal verification blockchain smart contract
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MF2-DMTD: A Formalism and Game-Based Reasoning Framework for Optimized Drone-Type Moving Target Defense
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作者 Sang Seo Jaeyeon Lee +2 位作者 Byeongjin Kim Woojin Lee Dohoon Kim 《Computers, Materials & Continua》 SCIE EI 2023年第11期2595-2628,共34页
Moving-target-defense(MTD)fundamentally avoids an illegal initial compromise by asymmetrically increasing the uncertainty as the attack surface of the observable defender changes depending on spatial-temporal mutation... Moving-target-defense(MTD)fundamentally avoids an illegal initial compromise by asymmetrically increasing the uncertainty as the attack surface of the observable defender changes depending on spatial-temporal mutations.However,the existing naive MTD studies were conducted focusing only on wired network mutations.And these cases have also been no formal research on wireless aircraft domains with attributes that are extremely unfavorable to embedded system operations,such as hostility,mobility,and dependency.Therefore,to solve these conceptual limitations,this study proposes normalized drone-type MTD that maximizes defender superiority by mutating the unique fingerprints of wireless drones and that optimizes the period-based mutation principle to adaptively secure the sustainability of drone operations.In addition,this study also specifies MF2-DMTD(model-checkingbased formal framework for drone-type MTD),a formal framework that adopts model-checking and zero-sum game,for attack-defense simulation and performance evaluation of drone-type MTD.Subsequently,by applying the proposed models,the optimization of deceptive defense performance of drone-type MTD for each mutation period also additionally achieves through mixed-integer quadratic constrained programming(MIQCP)and multiobjective optimization-based Pareto frontier.As a result,the optimal mutation cycles in drone-type MTD were derived as(65,120,85)for each control-mobility,telecommunication,and payload component configured inside the drone.And the optimal MTD cycles for each swarming cluster,ground control station(GCS),and zone service provider(ZSP)deployed outside the drone were also additionally calculated as(70,60,85),respectively.To the best of these authors’knowledge,this study is the first to calculate the deceptive efficiency and functional continuity of the MTD against drones and to normalize the trade-off according to a sensitivity analysis with the optimum. 展开更多
关键词 Moving-target-defense(MTD) DRONE formal methods game theory
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Generativity of Self-Organizing Processes and Their Correlative Description in Terms of a Formal Language of Meta-Ordinal Generative Nature, in the Light of the Maximum Ordinality Principle and the Explicit Solution to the “Three-Body Problem”
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作者 Corrado Giannantoni 《Journal of Applied Mathematics and Physics》 2023年第10期3159-3202,共44页
The main objective of this paper is to demonstrate that the internal processes of Self-Organizing Systems represent a unique and singular process, characterized by their specific generativity. This process can be mode... The main objective of this paper is to demonstrate that the internal processes of Self-Organizing Systems represent a unique and singular process, characterized by their specific generativity. This process can be modeled using the Maximum Ordinality Principle and its associated formal language, known as the “Incipient” Differential Calculus (IDC). 展开更多
关键词 Maximum Ordinality Principle Solution to the “Three-Body Problem” Generativity of Self-Organizing Processes formal Language of Ordinal Generativity formal Language of Meta-Ordinal Generativity
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Formalism of rotating-wave approximation in high-spin system with quadrupole interaction
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作者 丁文魁 王晓光 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第3期72-78,共7页
We investigate the rotating wave approximation applied in the high-spin quantum system driven by a linearly polarized alternating magnetic field in the presence of quadrupole interactions.The conventional way to apply... We investigate the rotating wave approximation applied in the high-spin quantum system driven by a linearly polarized alternating magnetic field in the presence of quadrupole interactions.The conventional way to apply the rotating wave approximation in a driven high-spin system is to assume the dynamics being restricted in the reduced Hilbert space.However,when the driving strength is relatively strong or the driving is off resonant,the leakage from the target resonance subspace cannot be neglected for a multi-level quantum system.We propose the correct formalism to apply the rotating wave approximation in the full Hilbert space by taking this leakage into account.By estimating the operator fidelity of the time propagator,our formalism applied in the full Hilbert space unambiguously manifests great advantages over the conventional method applied in the reduced Hilbert space. 展开更多
关键词 rotating wave approximation quadrupole interaction high-spin system
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Rice vs.Wheat:How Rice Farming Shaped Informal Finance in China
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作者 Zhang Bo Sun Tao 《China Economist》 2023年第3期94-111,共18页
China’s financial system is characterized by the coexistence of both formal and informal finance,and informal finance appears to be more prevalent in the south of the country compared to the north.In this paper,we us... China’s financial system is characterized by the coexistence of both formal and informal finance,and informal finance appears to be more prevalent in the south of the country compared to the north.In this paper,we use the historical demarcation of rice-farming regions and the percentage area of rice sown to ascertain the regional distribution of rice farming in the south and wheat farming in the north in order to analyze the role of rice farming in the evolution of different types of financial institutions in China.We find that rice cultivation has a positive effect on informal financial development,though its impact on formal finance is insignificant.Unlike wheat farming,rice cultivation requires farmers to collaborate during busy farming seasons and necessitates the construction of irrigation systems.Such collaboration helped enhance an acquaintance society,in which both parties to transactions enforced the rules and contract terms of their own initiative,paving the way for informal finance.This paper not only demonstrates the cultural roots of the regional financial disparities in China but also expands the research on the ways in which farming practices from the past have shaped the development of China’s present financial markets. 展开更多
关键词 Rice cultivation informal finance formal finance historical origins
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Relative Ding Projective Modules over Formal Triangular Matrix Rings
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作者 Hongyan Fan Xi Tang 《Journal of Applied Mathematics and Physics》 2023年第6期1598-1614,共17页
Let U be a (B, A)-bimodule, A and B be rings, and be a formal triangular matrix ring. In this paper, we characterize the structure of relative Ding projective modules over T under some conditions. Furthermore, using t... Let U be a (B, A)-bimodule, A and B be rings, and be a formal triangular matrix ring. In this paper, we characterize the structure of relative Ding projective modules over T under some conditions. Furthermore, using the left global relative Ding projective dimensions of A and B, we estimate the relative Ding projective dimension of a left T-module. 展开更多
关键词 formal Triangular Matrix Ring Relative Ding Projective Module Relative Ding Projective Dimension
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Radial Basis Approximations Based BEMD for Enhancement of Non-Uniform Illumination Images
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作者 Anchal Tyagi Salem Alelyani +3 位作者 Sapna Katiyar Mohammad Rashid Hussain Rijwan Khan Mohammed Saleh Alsaqer 《Computer Systems Science & Engineering》 SCIE EI 2023年第5期1423-1438,共16页
An image can be degraded due to many environmental factors like foggy or hazy weather,low light conditions,extra light conditions etc.Image captured under the poor light conditions is generally known as non-uniform il... An image can be degraded due to many environmental factors like foggy or hazy weather,low light conditions,extra light conditions etc.Image captured under the poor light conditions is generally known as non-uniform illumination image.Non-uniform illumination hides some important information present in an image during the image capture Also,it degrades the visual quality of image which generates the need for enhancement of such images.Various techniques have been present in literature for the enhancement of such type of images.In this paper,a novel architecture has been proposed for enhancement of poor illumination images which uses radial basis approximations based BEMD(Bi-dimensional Empirical Mode Decomposition).The enhancement algorithm is applied on intensity and saturation components of image.Firstly,intensity component has been decomposed into various bi-dimensional intrinsic mode function and residue by using sifting algorithm.Secondly,some linear transformations techniques have been applied on various bidimensional intrinsic modes obtained and residue and further on joining the transformed modes with residue,enhanced intensity component is obtained.Saturation part of an image is then enhanced in accordance to the enhanced intensity component.Final enhanced image can be obtained by joining the hue,enhanced intensity and enhanced saturation parts of the given image.The proposed algorithm will not only give the visual pleasant image but maintains the naturalness of image also. 展开更多
关键词 Non-uniform illumination BEMD intrinsic modes radial basis approximation linear transformation
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Approximations by Ideal Minimal Structure with Chemical Application
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作者 Rodyna A.Hosny Radwan Abu-Gdairi Mostafa K.El-Bably 《Intelligent Automation & Soft Computing》 SCIE 2023年第6期3073-3085,共13页
The theory of rough set represents a non-statistical methodology for analyzing ambiguity and imprecise information.It can be characterized by two crisp sets,named the upper and lower approximations that are used to de... The theory of rough set represents a non-statistical methodology for analyzing ambiguity and imprecise information.It can be characterized by two crisp sets,named the upper and lower approximations that are used to determine the boundary region and accurate measure of any subset.This article endeavors to achieve the best approximation and the highest accuracy degree by using the minimal structure approximation space MSAS via ideal J.The novel approach(indicated by JMSAS)modifies the approximation space to diminish the bound-ary region and enhance the measure of accuracy.The suggested method is more accurate than Pawlak’s and EL-Sharkasy techniques.Via illustrated examples,several remarkable results using these notions are obtained and some of their properties are established.Several sorts of near open(resp.closed)sets based on JMSAS are studied.Furthermore,the connections between these assorted kinds of near-open sets in JMSAS are deduced.The advantages and disadvan-tages of the proposed approach compared to previous ones are examined.An algorithm using MATLAB and a framework for decision-making problems are verified.Finally,the chemical application for the classification of amino acids(AAs)is treated to highlight the significance of applying the suggested approximation. 展开更多
关键词 IDEAL minimal structure spaces rough set theory approximation spaces
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Large High Altitude Air Shower Observatory Formally Kicks Off
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《Bulletin of the Chinese Academy of Sciences》 2023年第2期69-70,共2页
The Large High Altitude Air Shower Observatory(LHAASO),a major project as part of China’s national scientific and technological infrastructure,passed the national acceptance assessment and formally went into operatio... The Large High Altitude Air Shower Observatory(LHAASO),a major project as part of China’s national scientific and technological infrastructure,passed the national acceptance assessment and formally went into operation on May 10.Dedicated to cosmic ray observation and research,the design of LHAASO was approved by the national authorities on December 31,2015.Jointly sponsored by the Chinese Academy of Sciences(CAS)and the People’s Government of Sichuan Province,the construction of the principal part of the facility began in 2017 and was completed in 2021. 展开更多
关键词 formalLY ALTITUDE TOR
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双重制度视角下政府补贴对企业研发投入影响悖论的新解与验证 被引量:2
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作者 林春培 朱晓艳 +1 位作者 曾志盛 余传鹏 《管理工程学报》 CSCD 北大核心 2024年第3期108-121,共14页
本文利用中国A股上市公司2008—2020年的样本数据实证考察了政府补贴对企业研发投入的影响,并基于双重视角,即企业外部非正式制度层面的政治关联和内部正式制度层面的股权激励,探讨其对政府补贴与企业研发投入之间关系的调节作用。研究... 本文利用中国A股上市公司2008—2020年的样本数据实证考察了政府补贴对企业研发投入的影响,并基于双重视角,即企业外部非正式制度层面的政治关联和内部正式制度层面的股权激励,探讨其对政府补贴与企业研发投入之间关系的调节作用。研究结果表明:(1)适度的政府补贴有助于促进企业研发投入,即政府补贴对研发投入会产生倒U型影响;(2)政治关联会负向调节政府补贴与研发投入之间的倒U型关系;(3)股权激励与政府补贴之间具有互补作用,不仅能抵消过度补贴可能带来的抑制效应,还能进一步增强补贴初期对企业研发投入的激励效应,将两者的倒U型关系转变为正向线性关系。此外,内生性问题分析结果表明上述结论具有稳健性。该研究结论有助于我国政府合理制定补贴政策,为企业科学使用政府补贴以促进研发活动提供有益启示。 展开更多
关键词 政府补贴 正式制度 非正式制度 研发投入
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三支区间集半概念的代数结构及覆盖粗糙近似算子
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作者 毛华 牛振华 +3 位作者 马经泽 王刚 张植明 杨兰珍 《郑州大学学报(理学版)》 CAS 北大核心 2024年第6期84-90,共7页
针对在一个形式背景中以区间集为底集,考虑一个属性集(对象集)拥有的对象集(属性集)和不拥有的对象集(属性集)的知识表述而进行知识提取的问题,采取将区间集概念与三支决策、经典半概念相结合的方法,产生AE-区间集半概念和OE-区间集半... 针对在一个形式背景中以区间集为底集,考虑一个属性集(对象集)拥有的对象集(属性集)和不拥有的对象集(属性集)的知识表述而进行知识提取的问题,采取将区间集概念与三支决策、经典半概念相结合的方法,产生AE-区间集半概念和OE-区间集半概念两种形式的三支区间集半概念,同时发现AE-区间集半概念与OE-区间集半概念的纯双布尔代数结构。进一步深入讨论可知,AE-区间集半概念可分为AE1-区间集半概念与AE2-区间集半概念,利用粗糙集理论分别挖掘与AE1-区间集半概念和AE2-区间集半概念有关的近似算子的结构性质,对偶地可得OE-区间集半概念的相关结果。所得三支区间集半概念拓广了已有的三支决策集分别与区间集概念和半概念相结合的相关成果,成为一个新的知识表述。 展开更多
关键词 形式概念分析 半概念 三支决策 区间集概念 近似算子
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法治与形式原则的性能:以形式与实质关系为中心 被引量:1
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作者 侯健 《政治与法律》 北大核心 2024年第5期81-97,共17页
法治理论的争论主题之一是形式与实质的关系,其中涉及形式原则的性能。形式原则的性能可以从三个方面检视:形式性、自足性、充分性。形式原则具有形式性,但是并非纯粹,它们可能关涉法律规范的内容安排以及实质价值在规范内容上的贯彻效... 法治理论的争论主题之一是形式与实质的关系,其中涉及形式原则的性能。形式原则的性能可以从三个方面检视:形式性、自足性、充分性。形式原则具有形式性,但是并非纯粹,它们可能关涉法律规范的内容安排以及实质价值在规范内容上的贯彻效果,它们的解释适用也会受到实质价值的影响。形式原则具有指引法治实践的能力,但是并不自足,其自身无法解决遵守程度和例外问题,也无法消弭不同原则间的内在张力。对于有限、抽象的法治构成目标来说,形式原则可以作为构成条件,然而对于更具实践性的法治实现目标而言,就不敷其用了。法律的形式与实质相互联系,相互塑造。当法治对法律的形式提出要求,实践这种要求难免会牵连法律的实质。法治不可缺少形式原则,但是形式原则并非如通常想象的那样纯粹、自足和万能。 展开更多
关键词 法治 形式原则 形式性 自足性 充分性
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新能源电力系统不确定优化调度方法研究现状及展望 被引量:8
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作者 林舜江 冯祥勇 +2 位作者 梁炜焜 杨悦荣 刘明波 《电力系统自动化》 EI CSCD 北大核心 2024年第10期20-41,共22页
风电场和光伏电站出力的不确定性给电力系统优化调度带来很大技术挑战。文中主要介绍了考虑新能源不确定性的电力系统优化调度方法的研究现状及后续研究方向展望。首先,重点论述了各种不确定优化调度(UOD)方法,包括随机优化方法、鲁棒... 风电场和光伏电站出力的不确定性给电力系统优化调度带来很大技术挑战。文中主要介绍了考虑新能源不确定性的电力系统优化调度方法的研究现状及后续研究方向展望。首先,重点论述了各种不确定优化调度(UOD)方法,包括随机优化方法、鲁棒优化方法、随机鲁棒优化结合方法和基于人工智能技术的方法。其中,随机优化方法包括场景法、机会约束规划法和近似动态规划法;鲁棒优化方法包括传统鲁棒优化法和分布鲁棒优化法;随机鲁棒优化结合方法包括采样鲁棒优化法和分布鲁棒机会约束规划法。然后,介绍了每一种方法的优化模型形式、模型的转化和求解原理及其优缺点。最后,对UOD的后续重点研究方向进行展望,包括兼顾多个目标的UOD问题及多目标不确定优化方法、输配系统UOD问题及分布式不确定优化方法、考虑稳定性约束的UOD问题及含常微分方程约束的不确定优化方法、考虑管道传输动态的综合能源系统UOD问题及含偏微分方程约束的不确定优化方法。 展开更多
关键词 新能源电力系统 不确定优化调度 随机优化 鲁棒优化 近似动态规划
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现代逻辑思维对诗性的背离与回归——从罗素、维特根斯坦到伽达默尔 被引量:2
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作者 邓晓芒 《四川大学学报(哲学社会科学版)》 北大核心 2024年第1期52-65,209,共15页
亚里士多德创立的形式逻辑在原始思维中有其“互渗律”的起源,因而是基于语言本身的隐喻本性的,但直到康德,以往的隐喻都被理解为“使陌生变得熟悉”,成为形式逻辑的工具论,隐喻的“使熟悉变成陌生”的创新性一面却被忽视了。弗雷格和... 亚里士多德创立的形式逻辑在原始思维中有其“互渗律”的起源,因而是基于语言本身的隐喻本性的,但直到康德,以往的隐喻都被理解为“使陌生变得熟悉”,成为形式逻辑的工具论,隐喻的“使熟悉变成陌生”的创新性一面却被忽视了。弗雷格和罗素等从逻辑中清除了陌生的东西,使之变得数理化、僵化而无创造性,必然遇到“罗素悖论”而无法自拔;维特根斯坦是一个转折,从早期的分析哲学的逻辑观到晚期摆脱工具主义而转向语言游戏,有了西方逻辑思维从背离诗性到回归诗性的苗头;最后,经过伽达默尔对这一苗头的修正和发挥,将其扩展为诠释学的“语言学转向”,为隐喻和诗性打开了一片广阔的天地。可惜,他受到海德格尔和基督教传统“圣言”的局限,最终未能就此将其创造性的对话学说提升到“语言学之后”的形而上学,而沉陷于传统存在论(本体论)的“物理学之后”中。 展开更多
关键词 形式逻辑 隐喻 诗性 语言游戏 语言学转向
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基于改进凸内逼近法的主动配电网有功-无功协调优化 被引量:2
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作者 黄永红 王玉祥 +3 位作者 孔维健 曹程 苏家宇 王克威 《中国电机工程学报》 EI CSCD 北大核心 2024年第14期5528-5537,I0007,共11页
以风电、光伏为代表的分布式电源接入配电网后容易导致系统电压波动变大以及局部电压越限。以二阶锥优化为代表的松弛技术在优化时为了保证松弛后解的精确,约束条件极为严苛并且在功率的极端注入下容易导致对偶间隙增大。针对上述问题,... 以风电、光伏为代表的分布式电源接入配电网后容易导致系统电压波动变大以及局部电压越限。以二阶锥优化为代表的松弛技术在优化时为了保证松弛后解的精确,约束条件极为严苛并且在功率的极端注入下容易导致对偶间隙增大。针对上述问题,该文提出基于改进凸内逼近法的主动配电网有功-无功优化方法。首先,基于支路潮流方程定义与支路电流、节点电压和视在功率流相关的非线性项的凸包,并与剩余线性元素结合形成凸内部近似,建立完善的数学模型;进一步提出网络容许性判据以及引入KKT条件收缩最优解的对偶间隙。最后,基于IEEE 33系统及PG&E69节点系统,利用Yalmip等平台求得电网中各有功、无功决策变量的出力区间,验证所提方法的稳定、精确与高效性。 展开更多
关键词 分布式电源 凸内逼近 电压 调度区域
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金融能力、正规信贷约束与农户创业行为 被引量:1
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作者 周才云 刘森 《农林经济管理学报》 北大核心 2024年第1期70-78,共9页
基于金融能力和正规信贷约束视角,利用2017年和2019年CHFS微观数据,通过构建Probit模型实证分析金融能力对农户创业行为的影响,探讨正规信贷约束在金融能力和农户创业行为关系中发挥的中介效应。结果表明:金融能力对农户创业行为具有显... 基于金融能力和正规信贷约束视角,利用2017年和2019年CHFS微观数据,通过构建Probit模型实证分析金融能力对农户创业行为的影响,探讨正规信贷约束在金融能力和农户创业行为关系中发挥的中介效应。结果表明:金融能力对农户创业行为具有显著正向影响,且在考虑内生性的情况下,该结论仍然成立;中介机制检验表明,金融能力能够通过缓解正规信贷约束来促进农户创业行为;异质性分析表明,中、西部地区和三线及以下城市的农户金融能力对其创业行为的影响更为显著。据此,建议建立完善的金融能力培养体系,加大对欠发达地区的政策扶持,且提高正规信贷支持力度。 展开更多
关键词 金融能力 正规信贷约束 农户创业行为 因子分析法 PROBIT模型
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