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Opportunities to Improve the Quality of Environmental Reports and the Effectiveness of Environmental Impact Assessment: A Case of Electric Power Transmission Systems in Brazil
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作者 Vinícius Arthico Demori Marcelo Montaño 《Journal of Environmental Protection》 2024年第2期124-140,共17页
A good quality Environmental Impact Statement (EIS) is key for the effectiveness of Environmental Impact Assessment (EIA) processes and consequently to the acceptability of projects subject to EIA. The international l... A good quality Environmental Impact Statement (EIS) is key for the effectiveness of Environmental Impact Assessment (EIA) processes and consequently to the acceptability of projects subject to EIA. The international literature has contributed to the understanding of the essential aspects to be verified regarding the quality of EIS, offering a wide spectrum of good practice examples related to the content of the studies. Even so, there is a need for empirical studies that allow the identification of specific aspects related to the context of application of the EIS, which could lead to the identification of opportunities to improve both the quality of the reports and also the effectiveness of EIA. Therefore, the present paper is focused on the quality review of a number of EIS submitted to the Brazilian Federal Environmental Agency (Ibama) to instruct the assessment of electric power transmission systems. Based on the application of the EIS quality review package as proposed by Lee and Colley (1992), the outcomes reveal opportunities for improving the scope of EIA, analysis of alternatives, prediction of magnitude and the assessment of impact significance. Finally, the development and/or adaptation of a similar tool for the systematic review of the quality of EIA reports is recommended. 展开更多
关键词 Environmental Impact Assessment EFFECTIVENESS Electric Energy Transmission systems
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Reviewing Stability Criteria for Positive Homogeneous Systems and Adding One for Discrete-Time Cases with Degree Less Than One
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作者 Nguyen Quang Tuan 《Circuits and Systems》 2024年第1期1-11,共11页
The article synthesizes and presents the results regarding the stability of positive homogeneous systems that have been researched and published in recent years. Next, we provide a sufficient condition for global expo... The article synthesizes and presents the results regarding the stability of positive homogeneous systems that have been researched and published in recent years. Next, we provide a sufficient condition for global exponential stability in the case of discrete-time positive homogeneous systems with an order less than one with time-varying delays. 展开更多
关键词 Exponential Stability Homogeneous systems Positive systems Positive Homogeneous systems
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A Systems Approach to Assessing Sustainability Capacity in Kalobeyei Refugee Settlement in Turkana County, Kenya
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作者 Anicet Adjahossou 《Open Journal of Applied Sciences》 2024年第4期833-848,共16页
Refugee settlements face several challenges in transitioning from a temporary planning approach to more sustainable settlements. This is mainly due to an increase in the number of forcibly displaced people over the la... Refugee settlements face several challenges in transitioning from a temporary planning approach to more sustainable settlements. This is mainly due to an increase in the number of forcibly displaced people over the last few decades, and the difficulties of sustainably providing social services that meet the required standards. The development of refugee settlements assumed that forcibly displaced people would return to their places or countries of origin. Unfortunately, displacement situations are prolonged indefinitely, forcing these people to spend most of their lives in conditions that are often deplorable and substandard, and therefore unsustainable. In most cases, the establishment of refugee settlements is triggered by an emergency caused by an influx of forcibly displaced people, who need to be accommodated urgently and provided with some form of international assistance and protection. This leaves little or no time for proper planning for long-term development as required. In addition, the current approach to temporary settlement harms the environment and can strain limited resources with ad hoc development models that have exacerbated difficulties. As a result, living conditions in refugee settlements have deteriorated over the last few decades and continue to pose challenges as to how best to design, plan, and sustain settlements over time. To contribute to addressing these challenges, this study proposes a new methodology supported by Model-Based Systems Engineering (MBSE) and a Systems Modeling Language (SysML) to develop a typical sustainable human settlement system model, which has functionally and operationally executed using a Systems Engineering (SE) approach. To assess the sustainability capacity of the proposed system, this work applies a matrix of crossed impact multiplication through a case study by conducting a system capacity interdependence analysis (SCIA) using the MICMAC methodology (Cross-impact matrix multiplication applied to classification) to assess the interdependency that exist between the sub-systems categories to deliver services at the system level. The sustainability analysis results based on capacity variables influence and dependency models shows that development activities in the settlement are unstable and, therefore, unsustainable since there is no apparent difference between the influential and dependent data used for the assessment. These results illustrate that an integrated system could improve human settlements’ sustainability and that capacity building in service delivery is beneficial and necessary. 展开更多
关键词 Humanitarian Settlement systems Engineering (SE) SUSTAINABILITY Capacity Assessment Model-Based systems Engineering (MBSE) systems Modeling Language (SysML)
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Towards Automated Assessment of Learning Management Systems in Higher Education Institutions in Zambia
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作者 Memory Mumbi Mayumbo Nyirenda 《Open Journal of Applied Sciences》 2024年第5期1279-1294,共16页
Zambia like any other country in most African regions is still grappling with the dynamics of harnessing technology for the betterment of Higher Education. The onset of the Covid 19 pandemic brought a test for the pre... Zambia like any other country in most African regions is still grappling with the dynamics of harnessing technology for the betterment of Higher Education. The onset of the Covid 19 pandemic brought a test for the preparedness of the Zambian Higher Education Institutions (HEIs) in harnessing technology for pedagogical activities. As countries worldwide switched to electronic learning during the pandemic, the same could not be said for Zambian HEIs. Zambian HEIs struggled to conduct pedagogical activities on learning management platforms. This study investigated the factors affecting the implementation and assessment of learning Management systems in Zambia’s HEIs. With its focus on assessing: 1) system features, 2) compliance with regulatory standards, 3) quality of service and 4) technology acceptance as the four key assessment areas of an LMS, this article proposed a model for assessing learning management systems in Zambian HEIs. To test the proposed model, a software tool was also developed. 展开更多
关键词 Learning Management systems Assessment Model Technology Acceptance Education Technology
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公共草场自主治理实现机制——基于SES框架的案例分析
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作者 乌日汗 李平 +2 位作者 张苏日塔拉图 钱政成 王强 《草地学报》 CAS CSCD 北大核心 2024年第4期1021-1033,共13页
随着牧区社会-生态系统破碎化问题的凸显,公共草场自主治理引起了学术界关注。然而,中国现行草地承包制度下,自主治理制度的可行性及其实现机制仍有待系统研究。本文连续三年跟踪调查了内蒙古一片公共草场,应用SES框架解构了案例地复杂... 随着牧区社会-生态系统破碎化问题的凸显,公共草场自主治理引起了学术界关注。然而,中国现行草地承包制度下,自主治理制度的可行性及其实现机制仍有待系统研究。本文连续三年跟踪调查了内蒙古一片公共草场,应用SES框架解构了案例地复杂系统,并依据案例地情形构建了关联博弈模型,解析了公共草场自主治理制度下牧户互动机制。结果表明:草地资源的可持续利用关乎牧户长期生产成本。为了节约长期生产成本,牧区社区制定了公共草场自主治理制度。制度实施过程中,依据牧草长势和牲畜膘情形成了动态的草畜平衡规则,可操作的惩罚制度和地方政府弹性干预促进了自主治理制度的良好运作。同时,牧户之间的放牧博弈和社会交往博弈相互关联,使得自主治理制度以较低成本自我实施。该制度的有效实施有助于提高草地资源使用的公平性,也有利于牧户之间、牧户与地方政府之间信任的增长,提高生产互惠性和生产效率。因此,应探索建立自主治理和承包制度并存的多样化草地资源管理体系。 展开更多
关键词 自主治理 ses框架 关联博弈 草地资源管理
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Conventional Geothermal Systems and Unconventional Geothermal Developments: An Overview 被引量:1
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作者 Maryam Khodayar Sveinbjörn Björnsson 《Open Journal of Geology》 CAS 2024年第2期196-246,共51页
This paper provides an overview of conventional geothermal systems and unconventional geothermal developments as a common reference is needed for discussions between energy professionals. Conventional geothermal syste... This paper provides an overview of conventional geothermal systems and unconventional geothermal developments as a common reference is needed for discussions between energy professionals. Conventional geothermal systems have the heat, permeability and fluid, requiring only drilling down to °C, normal heat flow or decaying radiogenic granite as heat sources, and used in district heating. Medium-temperature (MT) 100°C - 190°C, and high-temperature (HT) 190°C - 374°C resources are mostly at plate boundaries, with volcanic intrusive heat source, used mostly for electricity generation. Single well capacities are °C - 500°C) and a range of depths (1 m to 20 Km), but lack permeability or fluid, thus requiring stimulations for heat extraction by conduction. HVAC is 1 - 2 m deep and shallow geothermal down to 500 m in wells, both capturing °C, with °C are either advanced by geothermal developers at <7 Km depth (Enhanced Geothermal Systems (EGS), drilling below brittle-ductile transition zones and under geothermal fields), or by the Oil & Gas industry (Advanced Geothermal Systems, heat recovery from hydrocarbon wells or reservoirs, Superhot Rock Geothermal, and millimeter-wave drilling down to 20 Km). Their primary aim is electricity generation, relying on closed-loops, but EGS uses fractures for heat exchange with earthquake risks during fracking. Unconventional approaches could be everywhere, with shallow geothermal already functional. The deeper and hotter unconventional alternatives are still experimental, overcoming costs and technological challenges to become fully commercial. Meanwhile, the conventional geothermal resources remain the most proven opportunities for investments and development. 展开更多
关键词 Conventional Geothermal systems Unconventional Geothermal Developments Shallow and Deep Closed-Loops Enhanced Geothermal systems Supercritical and Millimeter-Wave Drilling
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Computational Experiments for Complex Social Systems:Experiment Design and Generative Explanation 被引量:2
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作者 Xiao Xue Deyu Zhou +5 位作者 Xiangning Yu Gang Wang Juanjuan Li Xia Xie Lizhen Cui Fei-Yue Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第4期1022-1038,共17页
Powered by advanced information technology,more and more complex systems are exhibiting characteristics of the cyber-physical-social systems(CPSS).In this context,computational experiments method has emerged as a nove... Powered by advanced information technology,more and more complex systems are exhibiting characteristics of the cyber-physical-social systems(CPSS).In this context,computational experiments method has emerged as a novel approach for the design,analysis,management,control,and integration of CPSS,which can realize the causal analysis of complex systems by means of“algorithmization”of“counterfactuals”.However,because CPSS involve human and social factors(e.g.,autonomy,initiative,and sociality),it is difficult for traditional design of experiment(DOE)methods to achieve the generative explanation of system emergence.To address this challenge,this paper proposes an integrated approach to the design of computational experiments,incorporating three key modules:1)Descriptive module:Determining the influencing factors and response variables of the system by means of the modeling of an artificial society;2)Interpretative module:Selecting factorial experimental design solution to identify the relationship between influencing factors and macro phenomena;3)Predictive module:Building a meta-model that is equivalent to artificial society to explore its operating laws.Finally,a case study of crowd-sourcing platforms is presented to illustrate the application process and effectiveness of the proposed approach,which can reveal the social impact of algorithmic behavior on“rider race”. 展开更多
关键词 Agent-based modeling computational experiments cyber-physical-social systems(CPSS) generative deduction generative experiments meta model
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Prescribed Performance Tracking Control of Time-Delay Nonlinear Systems With Output Constraints 被引量:1
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作者 Jin-Xi Zhang Kai-Di Xu Qing-Guo Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第7期1557-1565,共9页
The problem of prescribed performance tracking control for unknown time-delay nonlinear systems subject to output constraints is dealt with in this paper. In contrast with related works, only the most fundamental requ... The problem of prescribed performance tracking control for unknown time-delay nonlinear systems subject to output constraints is dealt with in this paper. In contrast with related works, only the most fundamental requirements, i.e., boundedness and the local Lipschitz condition, are assumed for the allowable time delays. Moreover, we focus on the case where the reference is unknown beforehand, which renders the standard prescribed performance control designs under output constraints infeasible. To conquer these challenges, a novel robust prescribed performance control approach is put forward in this paper.Herein, a reverse tuning function is skillfully constructed and automatically generates a performance envelop for the tracking error. In addition, a unified performance analysis framework based on proof by contradiction and the barrier function is established to reveal the inherent robustness of the control system against the time delays. It turns out that the system output tracks the reference with a preassigned settling time and good accuracy,without constraint violations. A comparative simulation on a two-stage chemical reactor is carried out to illustrate the above theoretical findings. 展开更多
关键词 Nonlinear systems output constraints prescribed performance reference tracking time delays
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Relation of COVID-19 with liver diseases and their impact on healthcare systems:The Portuguese case
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作者 Sara Fernandes Milaydis Sosa-Napolskij +1 位作者 Graça Lobo Isabel Silva 《World Journal of Gastroenterology》 SCIE CAS 2023年第6期1109-1122,共14页
BACKGROUND The impact caused by the coronavirus disease 2019(COVID-19)on the Portuguese population has been addressed in areas such as clinical manifestations,frequent comorbidities,and alterations in consumption habi... BACKGROUND The impact caused by the coronavirus disease 2019(COVID-19)on the Portuguese population has been addressed in areas such as clinical manifestations,frequent comorbidities,and alterations in consumption habits.However,comorbidities like liver conditions and changes concerning the Portuguese population's access to healthcare-related services have received less attention.AIM To(1)Review the impact of COVID-19 on the healthcare system;(2)examine the relationship between liver diseases and COVID-19 in infected individuals;and(3)investigate the situation in the Portuguese population concerning these topics.METHODS For our purposes,we conducted a literature review using specific keywords.RESULTS COVID-19 is frequently associated with liver damage.However,liver injury in COVID-19 individuals is a multifactor-mediated effect.Therefore,it remains unclear whether changes in liver laboratory tests are associated with a worse prognosis in Portuguese individuals with COVID-19.CONCLUSION COVID-19 has impacted healthcare systems in Portugal and other countries;the combination of COVID-19 with liver injury is common.Previous liver damage may represent a risk factor that worsens the prognosis in individuals with COVID-19. 展开更多
关键词 COVID-19 Healthcare systems LIVER Portuguese individuals COMORBIDITIES Clinical outcomes
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Assessing Suitability of Irrigation Scheduling Decision Support Systems for Lowland Rice Farmers in Sub-Saharan Africa—A Review
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作者 Aloysius Mubangizi Joshua Wanyama +1 位作者 Nicholas Kiggundu Prossie Nakawuka 《Agricultural Sciences》 CAS 2023年第2期219-239,共21页
Irrigation in lowland rice production systems in Sub-Saharan Africa (SSA) is mainly based on traditional surface irrigation methods with continuous flooding practices. This irrigation method ends up using a lot more w... Irrigation in lowland rice production systems in Sub-Saharan Africa (SSA) is mainly based on traditional surface irrigation methods with continuous flooding practices. This irrigation method ends up using a lot more water that would have otherwise been used to open more land and be used in other water-requiring sectors. Various studies suggest Alternate Wetting and Drying (AWD) as an alternative practice for water management that reduces water use without significantly affecting yield. However, this practice has not been well adopted by the farmers despite its significant benefits of reduced total water use. Improving the adoption of AWD using irrigation Decision Support Systems (DSSs) helps the farmer on two fronts;to know “how much water to apply” and “when to irrigate”, which is very critical in maximizing productivity. This paper reviews the applicability of DSSs using AWD in lowland rice production systems in Sub-Saharan Africa. 展开更多
关键词 Lowland Rice Irrigation Scheduling Forecasting Decision Support systems Rice Production Farmer-Led Irrigation AWD
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Distributed dynamic event-based finite-time dissipative synchronization control for semi-Markov switched fuzzy cyber-physical systems against random packet losses
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作者 伍锡如 张煜翀 +1 位作者 张畑畑 张斌磊 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第10期328-342,共15页
This paper is concerned with the finite-time dissipative synchronization control problem of semi-Markov switched cyber-physical systems in the presence of packet losses, which is constructed by the Takagi–Sugeno fuzz... This paper is concerned with the finite-time dissipative synchronization control problem of semi-Markov switched cyber-physical systems in the presence of packet losses, which is constructed by the Takagi–Sugeno fuzzy model. To save the network communication burden, a distributed dynamic event-triggered mechanism is developed to restrain the information update. Besides, random packet dropouts following the Bernoulli distribution are assumed to occur in sensor to controller channels, where the triggered control input is analyzed via an equivalent method containing a new stochastic variable. By establishing the mode-dependent Lyapunov–Krasovskii functional with augmented terms, the finite-time boundness of the error system limited to strict dissipativity is studied. As a result of the help of an extended reciprocally convex matrix inequality technique, less conservative criteria in terms of linear matrix inequalities are deduced to calculate the desired control gains. Finally, two examples in regard to practical systems are provided to display the effectiveness of the proposed theory. 展开更多
关键词 cyber-physical systems finite-time synchronization distributed dynamic event-triggered mechanism random packet losses
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(Re)assessing Climate-Smart Agriculture practices for sustainable food systems outcomes in sub-Saharan Africa:The case of Bono East Region,Ghana
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作者 Philip Tetteh Quarshie Seidu Abdulai Evan D.G.Fraser 《Geography and Sustainability》 CSCD 2023年第2期112-126,共15页
This research paper assesses the reality of Climate-Smart Agriculture(CSA)practices’potential to promote the outcomes of sustainable food systems(SFS)within Ghana’s smallholding agriculture context.The study demon-s... This research paper assesses the reality of Climate-Smart Agriculture(CSA)practices’potential to promote the outcomes of sustainable food systems(SFS)within Ghana’s smallholding agriculture context.The study demon-strates that rural farmers generally perceive CSA’s contribution to‘food and nutrition security’and‘economic performance’as more important than CSA’s contribution to‘social equity’and‘environmental stewardship’.From a narrow perspective,the study demonstrates that farmers perceive CSA’s potential to‘prevent pest and disease outbreaks’and‘increase human capital information’as the most important contribution of CSA to SFS outcomes.In contrast,CSA’s potential to promote environmental stewardship is perceived as the least important among Ghana’s rural farmers.This enormity of displacement of smallholders’perceptions at large is motivated by de-mographic,socioeconomic and ecological factors.Moreso,the CSA for SFS outcomes narratives is driven by farmers’self-apprise,social networks and other local information dissemination agents.Furthermore,research findings suggest farmers’awareness of CSA practices and interventions is deficient owing to unmet training and information needs for approximately 82%of the CSA practices and interventions.This situation elucidates the dichotomy of CSA practices’narratives as tools for attaining food,nutrition security and economic performance to the detriment of critical issues such as increasing awareness and building farmers’capacity to engage with CSA practices while also managing socio-ecological trade-offs that emerge over time due to engagement with CSA.Critical(re)orientation is needed across the scale to drive CSA practices and interventions that confine cli-mate adaptation and food production practices within safe planetary boundaries without undermining social,economic,food and nutrition security needs. 展开更多
关键词 Climate adaptation Climate-Smart Agriculture Ghana Smallholder farmers Sustainable food systems Sub-Saharan Africa
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Group Hybrid Coordination Control of Multi-Agent Systems With Time-Delays and Additive Noises
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作者 Chuanjian Li Xiaofeng Zong 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第3期737-748,共12页
A new kind of group coordination control problemgroup hybrid coordination control is investigated in this paper.The group hybrid coordination control means that in a whole multi-agent system(MAS)that consists of two s... A new kind of group coordination control problemgroup hybrid coordination control is investigated in this paper.The group hybrid coordination control means that in a whole multi-agent system(MAS)that consists of two subgroups with communications between them,agents in the two subgroups achieve consensus and containment,respectively.For MASs with both time-delays and additive noises,two group control protocols are proposed to solve this problem for the containment-oriented case and consensus-oriented case,respectively.By developing a new analysis idea,some sufficient conditions and necessary conditions related to the communication intensity betw een the two subgroups are obtained for the following two types of group hybrid coordination behavior:1)Agents in one subgroup and in another subgroup achieve weak consensus and containment,respectively;2)Agents in one subgroup and in another subgroup achieve strong consensus and containment,respectively.It is revealed that the decay of the communication impact betw een the two subgroups is necessary for the consensus-oriented case.Finally,the validity of the group control results is verified by several simulation examples. 展开更多
关键词 Additive noises consensus control containment control group hybrid coordination control multi-agent systems(MASs) TIME-DELAYS
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Frequency Control Approach and Load Forecasting Assessment for Wind Systems
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作者 K.Sukanya P.Vijayakumar 《Intelligent Automation & Soft Computing》 SCIE 2023年第1期971-982,共12页
Frequency deviation has to be controlled in power generation units when there arefluctuations in system frequency.With several renewable energy sources,wind energy forecasting is majorly focused in this work which is ... Frequency deviation has to be controlled in power generation units when there arefluctuations in system frequency.With several renewable energy sources,wind energy forecasting is majorly focused in this work which is a tough task due to its variations and uncontrollable nature.Whenever there is a mismatch between generation and demand,the frequency deviation may arise from the actual frequency 50 Hz(in India).To mitigate the frequency deviation issue,it is necessary to develop an effective technique for better frequency control in wind energy systems.In this work,heuristic Fuzzy Logic Based Controller(FLC)is developed for providing an effective frequency control support by modeling the complex behavior of the system to enhance the load forecasting in wind based hybrid power systems.Frequency control is applied to reduce the frequency deviation due tofluctuations and load prediction information using ANN(Artificial Neural Network)and SVM(Support Vector Machine)learning models.The performance analysis of the proposed method is done with different machine learning based approaches.The forecasting assessment is done over various climates with the aim to decrease the prediction errors and to demote the forecasting accuracy.Simulation results show that the Mean Absolute Percentage Error(MAPE),Root Mean Square Error(RMSE)and Normalized Mean Absolute Error(NMAE)values are scaled down by 41.1%,9.9%and 23.1%respectively in the proposed method while comparing with existing wavelet and BPN based approach. 展开更多
关键词 Load forecasting wind power prediction fuzzy logic controller ANN SVM hybrid power systems
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Computation Tree Logic Model Checking of Multi-Agent Systems Based on Fuzzy Epistemic Interpreted Systems
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作者 Xia Li Zhanyou Ma +3 位作者 Zhibao Mian Ziyuan Liu Ruiqi Huang Nana He 《Computers, Materials & Continua》 SCIE EI 2024年第3期4129-4152,共24页
Model checking is an automated formal verification method to verify whether epistemic multi-agent systems adhere to property specifications.Although there is an extensive literature on qualitative properties such as s... Model checking is an automated formal verification method to verify whether epistemic multi-agent systems adhere to property specifications.Although there is an extensive literature on qualitative properties such as safety and liveness,there is still a lack of quantitative and uncertain property verifications for these systems.In uncertain environments,agents must make judicious decisions based on subjective epistemic.To verify epistemic and measurable properties in multi-agent systems,this paper extends fuzzy computation tree logic by introducing epistemic modalities and proposing a new Fuzzy Computation Tree Logic of Knowledge(FCTLK).We represent fuzzy multi-agent systems as distributed knowledge bases with fuzzy epistemic interpreted systems.In addition,we provide a transformation algorithm from fuzzy epistemic interpreted systems to fuzzy Kripke structures,as well as transformation rules from FCTLK formulas to Fuzzy Computation Tree Logic(FCTL)formulas.Accordingly,we transform the FCTLK model checking problem into the FCTL model checking.This enables the verification of FCTLK formulas by using the fuzzy model checking algorithm of FCTL without additional computational overheads.Finally,we present correctness proofs and complexity analyses of the proposed algorithms.Additionally,we further illustrate the practical application of our approach through an example of a train control system. 展开更多
关键词 Model checking multi-agent systems fuzzy epistemic interpreted systems fuzzy computation tree logic transformation algorithm
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The Challenges Posed by Autonomous Weapon Systems to Human Rights and Humanitarian Concerns and Relevant Legal Responses
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作者 张韵涵 XU Chao 《The Journal of Human Rights》 2023年第3期639-657,共19页
By 2050,autonomous weapon systems may potentially replace humans as the main force on the battlefield,as per predictions.The development of autonomous weapon systems poses risks to human rights and humanitarian concer... By 2050,autonomous weapon systems may potentially replace humans as the main force on the battlefield,as per predictions.The development of autonomous weapon systems poses risks to human rights and humanitarian concerns and raises questions about how international law should regulate new technologies.From the perspectives of international human rights law and international humanitarian law,autonomous weapon systems present serious challenges in terms of invasiveness,indiscriminate killing,cruelty,and loss of control,which impact human rights and humanitarian principles.Against the backdrop of increased attention to the protection of human rights in China,it is necessary to clarify the existing regulatory framework and fundamental stance regarding autonomous weapon systems and proactively consider and propose countermeasures to address the risks associated with such systems.This will help prevent human rights and humanitarian violations and advance the timely resolution of this issue,which affects the future and destiny of humanity,ultimately achieving the noble goal of universal enjoyment of human rights. 展开更多
关键词 autonomous weapon systems international humanitarian law international human rights law HUMANITARIAN
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Anomalous time-reversal symmetric non-Hermitian systems
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作者 易益妃 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期162-166,共5页
The conditions for the emergence of the non-Hermitian skin effect, as a unique physical response of non-Hermitian systems, have now become one of the hot research topics. In this paper, we study the novel physical res... The conditions for the emergence of the non-Hermitian skin effect, as a unique physical response of non-Hermitian systems, have now become one of the hot research topics. In this paper, we study the novel physical responses of nonHermitian systems with anomalous time-reversal symmetry, in both one dimension and two dimensions. Specifically, we focus on whether the systems will exhibit a non-Hermitian skin effect. We employ the theory of generalized Brillouin zone and also numerical methods to show that the anomalous time-reversal symmetry can prevent the skin effect in onedimensional non-Hermitian systems, but is unable to exert the same effectiveness in two-dimensional cases. 展开更多
关键词 skin effect SYMMETRY non-Hermitian systems
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Numerical simulation for the initial state of avalanche in polydisperse particle systems
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作者 韩韧 李亭 +2 位作者 迟志鹏 杨晖 李然 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期405-412,共8页
Numerical simulation is employed to investigate the initial state of avalanche in polydisperse particle systems.Nucleation and propagation processes are illustrated for pentadisperse and triadisperse particle systems,... Numerical simulation is employed to investigate the initial state of avalanche in polydisperse particle systems.Nucleation and propagation processes are illustrated for pentadisperse and triadisperse particle systems,respectively.In these processes,particles involved in the avalanche grow slowly in the early stage and explosively in the later stage,which is clearly different from the continuous and steady growth trend in the monodisperse system.By examining the avalanche propagation,the number growth of particles involved in the avalanche and the slope of the number growth,the initial state can be divided into three stages:T1(nucleation stage),T2(propagation stage),T3(overall avalanche stage).We focus on the characteristics of the avalanche in the T2 stage,and find that propagation distances increase almost linearly in both axial and radial directions in polydisperse systems.We also consider the distribution characteristics of the average coordination number and average velocity for the moving particles.The results support that the polydisperse particle systems are more stable in the T2 stage. 展开更多
关键词 AVALANCHE initial state polydisperse particle systems PROPAGATION
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Quantum discord and its dynamics for multipartite systems
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作者 罗嘉欣 郭琼 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期168-175,共8页
Quantum discord, one of the famous quantum correlations, has been recently generalized to multipartite systems by Radhakrishnan et al. Here we give analytical solutions of the quantum discord for a family of N-qubit q... Quantum discord, one of the famous quantum correlations, has been recently generalized to multipartite systems by Radhakrishnan et al. Here we give analytical solutions of the quantum discord for a family of N-qubit quantum states. For the bipartite system, we derive a zero quantum discord which will remain unchanged under the phase damping channel. For multiparitite systems, it is found that the quantum discord can be classified into three categories and the quantum discord for odd-partite systems can exhibit freezing under the phase damping channel, while the freezing does not exist in the even-partite systems. 展开更多
关键词 quantum discord multipartite systems decoherence channels frozen discord
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Bipartite consensus problems of Lurie multi-agent systems over signed graphs: A contraction approach
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作者 张晓娇 吴祥 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期137-145,共9页
This paper examines the bipartite consensus problems for the nonlinear multi-agent systems in Lurie dynamics form with cooperative and competitive communication between different agents. Based on the contraction theor... This paper examines the bipartite consensus problems for the nonlinear multi-agent systems in Lurie dynamics form with cooperative and competitive communication between different agents. Based on the contraction theory, some new conditions for the nonlinear Lurie multi-agent systems reaching bipartite leaderless consensus and bipartite tracking consensus are presented. Compared with the traditional methods, this approach degrades the dimensions of the conditions, eliminates some restrictions of the system matrix, and extends the range of the nonlinear function. Finally, two numerical examples are provided to illustrate the efficiency of our results. 展开更多
关键词 contraction theory virtual system bipartite consensus Lurie multi-agent systems
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