Ergodic stationary distribution of a stochastic rumor propagation model with general incidence function

In daily lives,when emergencies occur,rumors will spread widely on the internet.However,it is quite difficult for the netizens to distinguish the truth of the information.The main reasons are the uncertainty of netizens’behavior and attitude,which make the transmission rates of these information among social network groups be not fixed.In this paper,we propose a stochastic rumor propagation model with general incidence function.The model can be described by a stochastic differential equation.Applying the Khasminskii method via a suitable construction of Lyapunov function,we first prove the existence of a unique solution for the stochastic model with probability one.Then we show the existence of a unique ergodic stationary distribution of the rumor model,which exhibits the ergodicity.We also provide some numerical simulations to support our theoretical results.The numerical results give us some possible methods to control rumor propagation.Firstly,increasing noise intensity can effectively reduce rumor propagation when R_(0)>1That is,after rumors spread widely on social network platforms,government intervention and authoritative media coverage will interfere with netizens’opinions,thus reducing the degree of rumor propagation.Secondly,speed up the rumor refutation,intensify efforts to refute rumors,and improve the scientific quality of netizen(i.e.,increase the value ofβand decrease the value ofαandγ),which can effectively curb the rumor propagation.

数据跨境流动安全管理协同研究

[目的/意义]数据跨境流动推动了数字经济发展和国际交流合作,探索数据跨境流动安全管理协同问题,有利于维护数据安全和国家安全,促进数据利用体系与能力建设。[方法/过程]运用Nvivo软件,分析我国数据跨境流动安全管理协同存在的问题与产生的原因,基于协同理论和霍尔三维模型,构建数据跨境流动安全管理协同三维模型。[结果/结论]构建以组织协同机制、法制协同机制和资源协同机制3个子机制构成的数据跨境流动安全管理协同机制,并从知识共享、技术实力、文化环境3方面提出数据跨境流动安全管理协同机制运行保障措施,实现数据跨境流动安全管理协同效果。

德清县生态系统服务价值时空分析

生态系统服务价值评估作为合理配置土地资源、保护生态环境、助力碳交易、制定生态补偿标准的重要前提,是当今学术界的热点研究课题之一,而基于栅格的县域生态系统服务价值测算与分析,则对推动县域的高质量发展具有十分重要的意义。为此,本文以浙江省湖州市德清县作为研究对象,基于2010年、2015年、2020年德清县的国土数据和社会经济发展数据,运用物质量评价法及其协同与权衡分析,从测算德清县的生态系统服务价值入手,不但研究了该县生态系统服务价值的空间分布,以及各乡镇生态系统服务价值的时间序列变化情况,而且还对德清县及其德清县各个乡镇的不同生态系统服务价值之间的相关性进行了深入探索。研究结果表明:1)2010年、2015年、2020年德清县的生态系统服务价值分别为30.337亿元、35.906亿元、38.806亿元,呈现出了递增的发展趋势,而德清县生态系统服务价值的空间分布特征则是西部地区的生态系统服务价值高于中部和东部地区的生态系统服务价值。2)由2010年、2015年、2020年德清县各乡镇生态系统服务价值的时间序列变化情况可以看出,3年间德清县各乡镇的生态系统服务价值均呈现出了上升趋势。3)在德清县各生态系统服务价值之间的相关性方面,供给价值与固碳价值、释氧价值、水源涵养价值、土壤保持价值、生产有机质价值之间均表现为权衡关系;固碳价值、释氧价值、水源涵养价值、土壤保持价值、生产有机质价值之间则表现为协同关系。4)德清县大部分乡镇生态系统服务的固碳价值、释氧价值、水源涵养价值、土壤保持价值、生产有机质价值之间均表现为了协同关系。

A Framework for Exploring the Dynamics of Autonomous Work Groups in Manufacturing Organizations

Nowadays, new paradigm of enterprise organization i s constantly changing due to the emergence of the global marketplace, the rise of information technology, and the emphasis of the social developments. This re quires a more flexible form of organization that are more adaptable to rapid cha nges in business environment such as autonomous work groups (AWGs) in order to achieve higher productivity and effectiveness. AWGs are work units responsib le for the production of goods and the provision of services. They involve team members in making decisions that are traditionally the responsibility of the sup ervisors and managers (Cohen & Bailey, 1997). Team members of AWGs are allowed t o self-regulate their behavior on jobs such as task assignments, methods for ca rrying out the work, and scheduling of activities etc. (Cohen & Ledford, 1994). For example, Motorola achieved a high organizational performance due to the succ essful implementation of AWGs in quality management (Piczak & Hauser, 1996). Xer ox also reported their operational successes based on the team-oriented work gr oups (Wageman, 1997). In recent years many organizations have replaced the traditional layers of manag ement with autonomous team-based work arrangements. Surveys indicated that the adoption of AWGs has soared in responding to the competitive business challenges . Many enterprises are making a deliberate effort to use AWGs to carry out work and operational processes as an alternative for hierarchical approaches (Lawler et al., 1995). There is a growing body of evidence that AWGs are more effective than traditionally managed groups and they contributes to organizational perform ance, such as improvement in operational performance, productivity, quality, cos t savings, employee attitude and behavior, and employee satisfaction (e.g. Pears on, 1992; Cohen & Ledford, 1994; Seers et al. 1995). Given the complexity and cognitive nature of team-based organizations, the mech anisms that the enterprises use in the development of the increasingly sophistic ated models, which can contribute to the effective functioning of AWGs, are extr emely important. The process of developing effective AWGs enables enterprises to inherent built-in intelligence of the organizations so that they will be more able to accommodate to external pressures and changes. The context of this paper is the construction of a dynamics framework and a stra tegic path for autonomous work groups in the technology-oriented manufacturing organization re-design. The framework is a conceptual one drawn from the litera ture survey. The importance of studying autonomous work groups for today’s manuf acturing organizations is claimed. Based on the General System Theory (GST), the characterization of AWGs is addressed. Three-dimensional domains such as t echnical content, service content, and relationship content are identified. A st rategic path is proposed to guide the organizations how the development of AWGs progresses at different levels of maturity that are associated with organization al effectiveness and performance. The utility of the model for AWGs is expected to provide technology-oriented organizations with a strategic path to achieve h igher organizational performance.

基于土地利用情景模拟的喀斯特关键带生态系统服务权衡与协同分析—以蒙自喀斯特断陷盆地为例

以蒙自喀斯特断陷盆地为例,利用CLUE-S模型设置自然演化、微度、适度、强力生态治理情景并探究2030年不同情景对生态系统服务的影响及权衡与协同特征。结果表明:(1)2018年蒙自喀斯特断陷盆地植被净初级生产力(NPP)、产水量、覆盖型喀斯特区土壤保持量、裸露型喀斯特区土壤保持量、食物供给量分别增加了13.98%、38.97%、23.04%、25%、105.43%,且各种服务变化存在一定的空间差异性;(2)随着生态治理力度加大,2030年NPP和土壤保持量不断增加,产水量不断减少,食物供给量在强力生态治理情景下减少,在其他三种情景下增加;(3)NPP与产水量、食物供给量为权衡关系,与土壤保持量为协同关系;产水量与土壤保持量为权衡关系,与食物供给量为协同关系;土壤保持量与食物供给量为权衡关系;(4)相较于2018年,适度生态治理情景下四种生态系统服务之间的协调性最好,是较为合理的生态治理模式。

Exact Solutions of the Equilibrium Shape Equations in a General WLC Model for DNA Forms

In this letter,we are going to use a geometrical approach to describe the free energy of DNA structures.The exact solutions of the equilibrium shape equations in a general WLC model for DNA forms by using the Feoli's formalism [A.Feoli,et al.,Nucl.Phys.B 705(2005) 577] are studied.Then,the free energy of transition between Band Z-DNA is calculated in this formalism.

科技人才与科技创新的协同效应研究——基于广东2010-2016年面板数据的实证分析

文章在厘清科技人才与科技创新协同发展机理基础上,构建了科技人才与科技创新复合系统的指标体系和协同度测度模型,并基于广东2010-2016年面板数据,对科技人才与科技创新的系统协同度进行了实证分析。结果表明,广东科技人才与科技创新系统协同度呈轻微波动上升态势,2016年达到良好协同状态。

Exploring U.S.-China climate cooperation through linked carbon markets

Emissions trading systems(ETSs)are a widely used policy tool for driving emissions reductions and serve as an avenue for international climate cooperation.Following the recent global agreement on carbon market standards at COP26,this study explores linked ETSs as an avenue for the U.S.and China to cooperate on climate action.The emissions,energy,and economic effects of linked ETSs are analyzed through the China-in-Global Energy Model(C-GEM),a multi-regional,computable general equilibrium model.Assuming the development of national economy-wide ETSs,two scenarios are developed linking China and the U.S.:1)a bilateral U.S.-China ETS linkage 2)a multilateral ETS linkage that includes China,the U.S.,and nations in Southeast Asia.Results indicate that emissions and energy consumption outcomes would be similar in the bilateral and multilateral scenarios.However,economic outcomes are more favorable in the multilateral linkage scenario.When China and the U.S.engage in bilateral ETS linkage,China predominantly benefits from additional support for domestic decarbonization while the U.S.benefits from increased GDP compared to without ETS linkage.Adding Southeast Asia to establish multilateral linkage improves GDP outcomes for all participants,reducing adverse effects on China's GDP while boosting GDP for the U.S.and Southeast Asia.For policymakers considering the design and implementation of international ETSs,this study presents updated modeling on the effects of ETS linkage on each country as well as the economic benefits of expanding participation to additional regions.

On the Maximum of Wind Power Efficiency

In our paper we demonstrate that the filtration equation used by Gorban’ et al. for determining the maximum efficiency of plane propellers of about 30 percent for free fluids plays no role in describing the flows in the atmospheric boundary layer (ABL) because the ABL is mainly governed by turbulent motions. We also demonstrate that the stream tube model customarily applied to derive the Rankine-Froude theorem must be corrected in the sense of Glauert to provide an appropriate value for the axial velocity at the rotor area. Including this correction leads to the Betz-Joukowsky limit, the maximum efficiency of 59.3 percent. Thus, Gorban’ et al.’s 30% value may be valid in water, but it has to be discarded for the atmosphere. We also show that Joukowsky’s constant circulation model leads to values of the maximum efficiency which are higher than the Betz-Jow-kowsky limit if the tip speed ratio is very low. Some of these values, however, have to be rejected for physical reasons. Based on Glauert’s optimum actuator disk, and the results of the blade-element analysis by Okulov and S&oslashrensen we also illustrate that the maximum efficiency of propeller-type wind turbines depends on tip-speed ratio and the number of blades.