The dynamics of a solid spherical body in an oscillating liquid flow in a vertical axisymmetric channel of variable cross section is experimentally studied.It is shown that the oscillating liquid leads to the generati...The dynamics of a solid spherical body in an oscillating liquid flow in a vertical axisymmetric channel of variable cross section is experimentally studied.It is shown that the oscillating liquid leads to the generation of intense averaged flows in each of the channel segments.The intensity and direction of these flows depend on the dimensionless oscillating frequency.In the region of studied frequencies,the dynamics of the considered body is examined when the primary vortices emerging in the flow occupy the whole region in each segment.For a fixed frequency,an increase in the oscillation amplitude leads to a phase-inclusion holding effect,i.e.,the body occupies a quasi-stationary position in one of the cells of the vertical channel,while oscillating around its average position.It is also shown that the oscillating motion of a liquid column generates an averaged force acting on the body,the magnitude of which depends on the properties of the body and its position in the channel.The quasi-stationary position is determined by the relative density and size of the body,as well as the dimensionless frequency.The behavior of the body as a function of the amplitude and frequency of fluid oscillation and relative size is discussed in detail.Such findings may be used in the future to control the position of a phase inclusion and/or to strengthen mass transfer effects in a channel of variable cross section by means of fluid oscillations.展开更多
GHANA'S discovery of oil on its border with Cote d'Ivoire is testing the long-standing relationship between the two nations. The long running dispute over oil has led to Cote d'Ivoire's Director General of Hydroca...GHANA'S discovery of oil on its border with Cote d'Ivoire is testing the long-standing relationship between the two nations. The long running dispute over oil has led to Cote d'Ivoire's Director General of Hydrocarbons and Petroci unveiling a new maritime border with Ghana in November 2011, that includes some of the massive oil wealth in the western region, Ghana's Jubilee oil fields, as reported by Upstream, a global oil and gas publication.展开更多
Population-based algorithms have been used in many real-world problems.Bat algorithm(BA)is one of the states of the art of these approaches.Because of the super bat,on the one hand,BA can converge quickly;on the other...Population-based algorithms have been used in many real-world problems.Bat algorithm(BA)is one of the states of the art of these approaches.Because of the super bat,on the one hand,BA can converge quickly;on the other hand,it is easy to fall into local optimum.Therefore,for typical BA algorithms,the ability of exploration and exploitation is not strong enough and it is hard to find a precise result.In this paper,we propose a novel bat algorithm based on cross boundary learning(CBL)and uniform explosion strategy(UES),namely BABLUE in short,to avoid the above contradiction and achieve both fast convergence and high quality.Different from previous opposition-based learning,the proposed CBL can expand the search area of population and then maintain the ability of global exploration in the process of fast convergence.In order to enhance the ability of local exploitation of the proposed algorithm,we propose UES,which can achieve almost the same search precise as that of firework explosion algorithm but consume less computation resource.BABLUE is tested with numerous experiments on unimodal,multimodal,one-dimensional,high-dimensional and discrete problems,and then compared with other typical intelligent optimization algorithms.The results show that the proposed algorithm outperforms other algorithms.展开更多
An analysis is presented to study the dual nature of solutions for the forced convective boundary layer flow and heat transfer in a cross flow with viscous dissipation terms in the energy equation. The governing equat...An analysis is presented to study the dual nature of solutions for the forced convective boundary layer flow and heat transfer in a cross flow with viscous dissipation terms in the energy equation. The governing equations are transformed into a set of three self-similar ordinary differential equations by similarity transformations. These equations are solved numerically using the very efficient shooting method. This study reveals that the dual solutions of the transformed similarity equations for velocity and temperature distributions exist for certain values of the moving parameter, Prandtl number, and Eckert numbers. The reverse heat flux is observed for larger Eckert numbers; that is, heat absorption at the wall occurs.展开更多
This paper reports study focusing on the effects of sloping bottom on the deep cross-equatorial boundary current, and discusses model and laboratory experiment results showing that the southward that the southward int...This paper reports study focusing on the effects of sloping bottom on the deep cross-equatorial boundary current, and discusses model and laboratory experiment results showing that the southward that the southward intrusion distance and flow speed of the western boundary current depend on the bottom slope variation rate,the difference between and and are the current thickness at eastward edge and westward edge, respectively), and the net mass transport.展开更多
跨界团队在企业等创新主体开展颠覆性创新活动中发挥重要作用,而运用机器学习方法识别其网络特征与颠覆性创新绩效之间殊途同归的组态路径是一个亟待解决的重要问题。本文基于Incopat专利检索平台无人机领域139999条专利数据,采用社区...跨界团队在企业等创新主体开展颠覆性创新活动中发挥重要作用,而运用机器学习方法识别其网络特征与颠覆性创新绩效之间殊途同归的组态路径是一个亟待解决的重要问题。本文基于Incopat专利检索平台无人机领域139999条专利数据,采用社区发现算法在专利发明人合作关系数据中识别185个跨界团队,依据社会网络理论遴选跨界团队网络特征变量,利用k-means聚类算法对跨界团队进行类型划分,并运用决策树CART(classification and regression trees)算法挖掘不同类型跨界团队网络特征对其颠覆性创新绩效的影响。研究结果表明,①跨界团队共有二元合作、类完全合作和复杂合作3种合作类型,不同跨界团队类型对颠覆性创新绩效影响具有差异性,即类完全合作团队高颠覆性创新绩效占比最高,二元合作团队高颠覆性创新绩效占比最低;②合作强度具有普适性,它是影响不同跨界团队形成不同水平颠覆性创新绩效的核心因素;③合作强度正向影响二元合作团队颠覆性创新绩效,类完全合作团队的颠覆性创新绩效受聚集系数、合作强度与团队规模的共同影响,而对于合作强度较高的复杂合作团队而言,保持较低的网络密度有利于其提升颠覆性创新绩效。展开更多
近年来,随着普适计算概念的深入人心,智能感知技术已成为研究者们关注的焦点,且基于WiFi的非接触式感知因其优秀的普适性、低廉的部署成本以及良好的用户体验越来越受到学术界和工业界的青睐.典型的WiFi非接触式感知工作有手势识别、呼...近年来,随着普适计算概念的深入人心,智能感知技术已成为研究者们关注的焦点,且基于WiFi的非接触式感知因其优秀的普适性、低廉的部署成本以及良好的用户体验越来越受到学术界和工业界的青睐.典型的WiFi非接触式感知工作有手势识别、呼吸检测、入侵检测、行为识别等,这些工作若实际部署,需首先避免其他无关区域中无关行为的干扰,因此需要判断目标是否进入到特定的感知区域中.这意味着系统应具备精准判断目标在界线哪一侧的能力,然而现有工作未能找到一个可以对某个自由设定的边界进行精确监控的方法,这阻碍了WiFi感知应用的实际落地.基于这一关键问题,从电磁波衍射的物理本质出发,结合菲涅尔衍射模型(Fresnel diffraction model),找到一种目标穿越link(收发设备天线的连线)时的信号特征(Rayleigh distribution in Fresnel diffraction model,RFD),并揭示该信号特征与人体活动之间的数学关系;之后以link作为边界,结合天线间距带来的波形时延以及AGC(automatic gain control)在link被遮挡时的特征,通过越线检测实现对边界的监控.在此基础上,还实现了两个实际应用,即入侵检测系统和居家状态监测系统,前者的精确率超过89%、召回率超过91%,后者的准确率超过89%.在验证所提边界监控算法的可用性和鲁棒性的同时,也展示了所提方法与其他WiFi感知技术相结合的巨大潜力,为WiFi感知技术的实际部署提供了思考方向.展开更多
In order to construct cooperation platform for the treatment of water pollution in Changjiang River,thoughts and revolution were performed from both central government and regional area two aspects.From the national l...In order to construct cooperation platform for the treatment of water pollution in Changjiang River,thoughts and revolution were performed from both central government and regional area two aspects.From the national level,Changjiang region water resources management cooperation counsel committee was constructed as the national cooperation platform;from the regional level,Changjiang region water resources management cooperation counsel committee was constructed as the platform of Changjiang cooperation platform.The two platforms built fine interaction mechanism to deal with the national water management and Changjiang regional water management.展开更多
文摘The dynamics of a solid spherical body in an oscillating liquid flow in a vertical axisymmetric channel of variable cross section is experimentally studied.It is shown that the oscillating liquid leads to the generation of intense averaged flows in each of the channel segments.The intensity and direction of these flows depend on the dimensionless oscillating frequency.In the region of studied frequencies,the dynamics of the considered body is examined when the primary vortices emerging in the flow occupy the whole region in each segment.For a fixed frequency,an increase in the oscillation amplitude leads to a phase-inclusion holding effect,i.e.,the body occupies a quasi-stationary position in one of the cells of the vertical channel,while oscillating around its average position.It is also shown that the oscillating motion of a liquid column generates an averaged force acting on the body,the magnitude of which depends on the properties of the body and its position in the channel.The quasi-stationary position is determined by the relative density and size of the body,as well as the dimensionless frequency.The behavior of the body as a function of the amplitude and frequency of fluid oscillation and relative size is discussed in detail.Such findings may be used in the future to control the position of a phase inclusion and/or to strengthen mass transfer effects in a channel of variable cross section by means of fluid oscillations.
文摘GHANA'S discovery of oil on its border with Cote d'Ivoire is testing the long-standing relationship between the two nations. The long running dispute over oil has led to Cote d'Ivoire's Director General of Hydrocarbons and Petroci unveiling a new maritime border with Ghana in November 2011, that includes some of the massive oil wealth in the western region, Ghana's Jubilee oil fields, as reported by Upstream, a global oil and gas publication.
基金Supported by the National Natural Science Foundation of China(61472289)the Open Project Program of the State Key Laboratory of Digital Manufacturing Equipment and Technology(DMETKF2017016)
文摘Population-based algorithms have been used in many real-world problems.Bat algorithm(BA)is one of the states of the art of these approaches.Because of the super bat,on the one hand,BA can converge quickly;on the other hand,it is easy to fall into local optimum.Therefore,for typical BA algorithms,the ability of exploration and exploitation is not strong enough and it is hard to find a precise result.In this paper,we propose a novel bat algorithm based on cross boundary learning(CBL)and uniform explosion strategy(UES),namely BABLUE in short,to avoid the above contradiction and achieve both fast convergence and high quality.Different from previous opposition-based learning,the proposed CBL can expand the search area of population and then maintain the ability of global exploration in the process of fast convergence.In order to enhance the ability of local exploitation of the proposed algorithm,we propose UES,which can achieve almost the same search precise as that of firework explosion algorithm but consume less computation resource.BABLUE is tested with numerous experiments on unimodal,multimodal,one-dimensional,high-dimensional and discrete problems,and then compared with other typical intelligent optimization algorithms.The results show that the proposed algorithm outperforms other algorithms.
文摘An analysis is presented to study the dual nature of solutions for the forced convective boundary layer flow and heat transfer in a cross flow with viscous dissipation terms in the energy equation. The governing equations are transformed into a set of three self-similar ordinary differential equations by similarity transformations. These equations are solved numerically using the very efficient shooting method. This study reveals that the dual solutions of the transformed similarity equations for velocity and temperature distributions exist for certain values of the moving parameter, Prandtl number, and Eckert numbers. The reverse heat flux is observed for larger Eckert numbers; that is, heat absorption at the wall occurs.
文摘This paper reports study focusing on the effects of sloping bottom on the deep cross-equatorial boundary current, and discusses model and laboratory experiment results showing that the southward that the southward intrusion distance and flow speed of the western boundary current depend on the bottom slope variation rate,the difference between and and are the current thickness at eastward edge and westward edge, respectively), and the net mass transport.
文摘跨界团队在企业等创新主体开展颠覆性创新活动中发挥重要作用,而运用机器学习方法识别其网络特征与颠覆性创新绩效之间殊途同归的组态路径是一个亟待解决的重要问题。本文基于Incopat专利检索平台无人机领域139999条专利数据,采用社区发现算法在专利发明人合作关系数据中识别185个跨界团队,依据社会网络理论遴选跨界团队网络特征变量,利用k-means聚类算法对跨界团队进行类型划分,并运用决策树CART(classification and regression trees)算法挖掘不同类型跨界团队网络特征对其颠覆性创新绩效的影响。研究结果表明,①跨界团队共有二元合作、类完全合作和复杂合作3种合作类型,不同跨界团队类型对颠覆性创新绩效影响具有差异性,即类完全合作团队高颠覆性创新绩效占比最高,二元合作团队高颠覆性创新绩效占比最低;②合作强度具有普适性,它是影响不同跨界团队形成不同水平颠覆性创新绩效的核心因素;③合作强度正向影响二元合作团队颠覆性创新绩效,类完全合作团队的颠覆性创新绩效受聚集系数、合作强度与团队规模的共同影响,而对于合作强度较高的复杂合作团队而言,保持较低的网络密度有利于其提升颠覆性创新绩效。
文摘近年来,随着普适计算概念的深入人心,智能感知技术已成为研究者们关注的焦点,且基于WiFi的非接触式感知因其优秀的普适性、低廉的部署成本以及良好的用户体验越来越受到学术界和工业界的青睐.典型的WiFi非接触式感知工作有手势识别、呼吸检测、入侵检测、行为识别等,这些工作若实际部署,需首先避免其他无关区域中无关行为的干扰,因此需要判断目标是否进入到特定的感知区域中.这意味着系统应具备精准判断目标在界线哪一侧的能力,然而现有工作未能找到一个可以对某个自由设定的边界进行精确监控的方法,这阻碍了WiFi感知应用的实际落地.基于这一关键问题,从电磁波衍射的物理本质出发,结合菲涅尔衍射模型(Fresnel diffraction model),找到一种目标穿越link(收发设备天线的连线)时的信号特征(Rayleigh distribution in Fresnel diffraction model,RFD),并揭示该信号特征与人体活动之间的数学关系;之后以link作为边界,结合天线间距带来的波形时延以及AGC(automatic gain control)在link被遮挡时的特征,通过越线检测实现对边界的监控.在此基础上,还实现了两个实际应用,即入侵检测系统和居家状态监测系统,前者的精确率超过89%、召回率超过91%,后者的准确率超过89%.在验证所提边界监控算法的可用性和鲁棒性的同时,也展示了所提方法与其他WiFi感知技术相结合的巨大潜力,为WiFi感知技术的实际部署提供了思考方向.
基金Supported by National Social Science Fund Program " Study on Negotiation Mode,Mechanism and Policy of Cross-border Water Pollution Treatment in Changjiang River Delta Area"(09BFX042)Key Subject Industry Economics Subject of East China University of Political Science and Law(CJ10-008)~~
文摘In order to construct cooperation platform for the treatment of water pollution in Changjiang River,thoughts and revolution were performed from both central government and regional area two aspects.From the national level,Changjiang region water resources management cooperation counsel committee was constructed as the national cooperation platform;from the regional level,Changjiang region water resources management cooperation counsel committee was constructed as the platform of Changjiang cooperation platform.The two platforms built fine interaction mechanism to deal with the national water management and Changjiang regional water management.