随着集成电路技术的飞速发展,其集成度和复杂度越来越高,导致芯片功耗问题日益严重。文章提出一套兼容片上网络(Net on Chip,NoC)总线的功耗管理总线,针对不同电源域进行低功耗管理,通过电源域开关协议将电源域状态同步到事务活动,且不...随着集成电路技术的飞速发展,其集成度和复杂度越来越高,导致芯片功耗问题日益严重。文章提出一套兼容片上网络(Net on Chip,NoC)总线的功耗管理总线,针对不同电源域进行低功耗管理,通过电源域开关协议将电源域状态同步到事务活动,且不影响系统其他部分的操作。实验结果表明,功耗管理总线具有低成本、协议简单、兼容性好、轻量级等优势。展开更多
An electromagnetic field is generated through the accelerating movement of two equal but opposite charges of a single dipole. An electromagnetic field can also be generated by a time-varying infinitesimal point charge...An electromagnetic field is generated through the accelerating movement of two equal but opposite charges of a single dipole. An electromagnetic field can also be generated by a time-varying infinitesimal point charge. In this study, a comparison between the electromagnetic fields of an infinitesimal point charge and a dipole has been presented. First, the time-domain potential function of a point source in a 3D conductive medium is derived. Then the electric and magnetic fields in a 3D homogeneous lossless space are derived via the relation between the potential and field. The field differences between the infinitesimal point charge and the dipole in the step-off time, far-source, and near-source zones are analyzed, and the accuracy of the solutions from these sources is investigated. It is also shown that the field of the infinitesimal point charge in the near-source zone is different from that of the dipole, whereas the far-source zone fields of these two sources are identical. The comparison of real and simulated data shows that the infinitesimal point charge represents the real source better than the divole source.展开更多
图形处理器(Graphics Process Unit,GPU)作为整个手机系统及芯片(System On Chip,SoC)的重要组成部分,除了具有提供高性能的图形图像处理能力之外,减少功耗也是移动平台图形处理器设计者们需要考虑的关键问题之一。在经典图形处理器芯...图形处理器(Graphics Process Unit,GPU)作为整个手机系统及芯片(System On Chip,SoC)的重要组成部分,除了具有提供高性能的图形图像处理能力之外,减少功耗也是移动平台图形处理器设计者们需要考虑的关键问题之一。在经典图形处理器芯片的基础上,一种新的低功耗高性能的图形绘制解决方案着重从架构层面解决功耗的问题。通过显卡驱动端的配合,将很多通用手机应用程序的三维绘制任务转换成低功耗绘制命令,绕开复杂的指令执行单元高效的完成绘制任务,同时通过将整个指令执行单元划分在独立的电源域,进行电源门控,将功耗大大降低。实验表明,对某些典型应用场景,新的解决方案最多可以节省50%的功耗。展开更多
A modeling tool for simulating three-dimensional land frequency-domain controlled-source electromagnetic surveys,based on a finite-element discretization of the Helmholtz equation for the electric fields,has been deve...A modeling tool for simulating three-dimensional land frequency-domain controlled-source electromagnetic surveys,based on a finite-element discretization of the Helmholtz equation for the electric fields,has been developed.The main difference between our modeling method and those previous works is edge finite-element approach applied to solving the three-dimensional land frequency-domain electromagnetic responses generated by horizontal electric dipole source.Firstly,the edge finite-element equation is formulated through the Galerkin method based on Helmholtz equation of the electric fields.Secondly,in order to check the validity of the modeling code,the numerical results are compared with the analytical solutions for a homogeneous half-space model.Finally,other three models are simulated with three-dimensional electromagnetic responses.The results indicate that the method can be applied for solving three-dimensional electromagnetic responses.The algorithm has been demonstrated,which can be effective to modeling the complex geo-electrical structures.This efficient algorithm will help to study the distribution laws of3-D land frequency-domain controlled-source electromagnetic responses and to setup basis for research of three-dimensional inversion.展开更多
Based on the energy distribution and economy status In the Northwest Region in China, this paper analyzes the probability of power sources complementation between Northwest Power Grid and the adjacent regional power g...Based on the energy distribution and economy status In the Northwest Region in China, this paper analyzes the probability of power sources complementation between Northwest Power Grid and the adjacent regional power grids, and points out that the strategic emphases for Northwest power development are to speed up 750 kV transmis-sion system construction, expand the Regional power market, rolling-develop hydrdpower stations on the Upper Yellow River, speed up thermal power bases construction and boost the interconnection between Northwest and North China, etc.展开更多
This work aims to control pulsed power for biomedical fields, which demands sensitive parameters. The pulsed power consists of a voltage rise time of less than 50 ns and charging energy to 1.0 J/pulse; also, the pulse...This work aims to control pulsed power for biomedical fields, which demands sensitive parameters. The pulsed power consists of a voltage rise time of less than 50 ns and charging energy to 1.0 J/pulse; also, the pulse control area includes pulse interval pulse shot number, output voltage. To achieve this system, a pulsed power system exists including software running on PC, universal serial bus （UgB~ for connection, and FPGA controller. Using the software for complex control of pulsed power will enable expansion into various fields with easy operation.展开更多
Clean energy is the most promising technology for sustainable growth. The development of clean energy requires a considerable amount of R ＆ D （research ＆ development） expenditure and various core technologies, and...Clean energy is the most promising technology for sustainable growth. The development of clean energy requires a considerable amount of R ＆ D （research ＆ development） expenditure and various core technologies, and therefore, international research collaboration is necessary for prompt and efficient development. The study is aimed at establishing a knowledge base that can help to prepare international research collaboration policies for solving global challenges effectively. The authors demonstrate the research capacity and international research collaboration in solar cell and fuel cell technologies, using global research network diagrams gathered from 35,322 and 33,136 academic papers, respectively. The diagrams include the data of research competency and co-authorship. More than 6,000 institutions and 100 countries are involved in each field. Based on the diagrams, the technologies are compared and international collaboration is analyzed. A valley of research collaboration in Asia is identified for both technologies. Then, science and education policies that influence the structures are discussed.展开更多
文摘随着集成电路技术的飞速发展,其集成度和复杂度越来越高,导致芯片功耗问题日益严重。文章提出一套兼容片上网络(Net on Chip,NoC)总线的功耗管理总线,针对不同电源域进行低功耗管理,通过电源域开关协议将电源域状态同步到事务活动,且不影响系统其他部分的操作。实验结果表明,功耗管理总线具有低成本、协议简单、兼容性好、轻量级等优势。
基金supported by Chinese National Programs for Fundamental Research and Development(No.2012CB416605)the National Natural Science Foundation of China(No.41174090)Development Project of National Key Scientific Equipment(No.ZDYZ2012-1-05-04)
文摘An electromagnetic field is generated through the accelerating movement of two equal but opposite charges of a single dipole. An electromagnetic field can also be generated by a time-varying infinitesimal point charge. In this study, a comparison between the electromagnetic fields of an infinitesimal point charge and a dipole has been presented. First, the time-domain potential function of a point source in a 3D conductive medium is derived. Then the electric and magnetic fields in a 3D homogeneous lossless space are derived via the relation between the potential and field. The field differences between the infinitesimal point charge and the dipole in the step-off time, far-source, and near-source zones are analyzed, and the accuracy of the solutions from these sources is investigated. It is also shown that the field of the infinitesimal point charge in the near-source zone is different from that of the dipole, whereas the far-source zone fields of these two sources are identical. The comparison of real and simulated data shows that the infinitesimal point charge represents the real source better than the divole source.
文摘图形处理器(Graphics Process Unit,GPU)作为整个手机系统及芯片(System On Chip,SoC)的重要组成部分,除了具有提供高性能的图形图像处理能力之外,减少功耗也是移动平台图形处理器设计者们需要考虑的关键问题之一。在经典图形处理器芯片的基础上,一种新的低功耗高性能的图形绘制解决方案着重从架构层面解决功耗的问题。通过显卡驱动端的配合,将很多通用手机应用程序的三维绘制任务转换成低功耗绘制命令,绕开复杂的指令执行单元高效的完成绘制任务,同时通过将整个指令执行单元划分在独立的电源域,进行电源门控,将功耗大大降低。实验表明,对某些典型应用场景,新的解决方案最多可以节省50%的功耗。
基金Projects(41674080,41674079)supported by the National Natural Science Foundation of China
文摘A modeling tool for simulating three-dimensional land frequency-domain controlled-source electromagnetic surveys,based on a finite-element discretization of the Helmholtz equation for the electric fields,has been developed.The main difference between our modeling method and those previous works is edge finite-element approach applied to solving the three-dimensional land frequency-domain electromagnetic responses generated by horizontal electric dipole source.Firstly,the edge finite-element equation is formulated through the Galerkin method based on Helmholtz equation of the electric fields.Secondly,in order to check the validity of the modeling code,the numerical results are compared with the analytical solutions for a homogeneous half-space model.Finally,other three models are simulated with three-dimensional electromagnetic responses.The results indicate that the method can be applied for solving three-dimensional electromagnetic responses.The algorithm has been demonstrated,which can be effective to modeling the complex geo-electrical structures.This efficient algorithm will help to study the distribution laws of3-D land frequency-domain controlled-source electromagnetic responses and to setup basis for research of three-dimensional inversion.
文摘Based on the energy distribution and economy status In the Northwest Region in China, this paper analyzes the probability of power sources complementation between Northwest Power Grid and the adjacent regional power grids, and points out that the strategic emphases for Northwest power development are to speed up 750 kV transmis-sion system construction, expand the Regional power market, rolling-develop hydrdpower stations on the Upper Yellow River, speed up thermal power bases construction and boost the interconnection between Northwest and North China, etc.
文摘This work aims to control pulsed power for biomedical fields, which demands sensitive parameters. The pulsed power consists of a voltage rise time of less than 50 ns and charging energy to 1.0 J/pulse; also, the pulse control area includes pulse interval pulse shot number, output voltage. To achieve this system, a pulsed power system exists including software running on PC, universal serial bus （UgB~ for connection, and FPGA controller. Using the software for complex control of pulsed power will enable expansion into various fields with easy operation.
文摘Clean energy is the most promising technology for sustainable growth. The development of clean energy requires a considerable amount of R ＆ D （research ＆ development） expenditure and various core technologies, and therefore, international research collaboration is necessary for prompt and efficient development. The study is aimed at establishing a knowledge base that can help to prepare international research collaboration policies for solving global challenges effectively. The authors demonstrate the research capacity and international research collaboration in solar cell and fuel cell technologies, using global research network diagrams gathered from 35,322 and 33,136 academic papers, respectively. The diagrams include the data of research competency and co-authorship. More than 6,000 institutions and 100 countries are involved in each field. Based on the diagrams, the technologies are compared and international collaboration is analyzed. A valley of research collaboration in Asia is identified for both technologies. Then, science and education policies that influence the structures are discussed.
