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调度自动化系统中计算量点的应用 被引量:1
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作者 龚强 王向东 《电力自动化设备》 EI CSCD 2000年第5期54-56,59,共4页
随着计算机技术的发展 ,调度自动化系统的计算量点资源较前有比较大的裕度。怎样进一步利用这些资源 ,增强调度自动化系统的功能 ,是调度自动化系统实用化工作开展以后的一项具体工作。介绍了利用计算量点 ,完成实时线损变损计算、电容... 随着计算机技术的发展 ,调度自动化系统的计算量点资源较前有比较大的裕度。怎样进一步利用这些资源 ,增强调度自动化系统的功能 ,是调度自动化系统实用化工作开展以后的一项具体工作。介绍了利用计算量点 ,完成实时线损变损计算、电容器投切容量和统计分析、功率因数计算。 展开更多
关键词 电网 调度自动化系统 计算量点
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调度自动化系统中计算量点的应用
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作者 龚强 王向东 《东北电力技术》 2000年第1期12-15,共4页
随着计算机技术的发展,调度自动化系统的计算量点资源较前有比较大的宽松。怎样进一步利用这些资源,增强调度自动化系统的功能,是调度自动化系统实用化工作开展以后的一项具体工作。本文介绍了利用计算量点,完成实时线损变损计算、... 随着计算机技术的发展,调度自动化系统的计算量点资源较前有比较大的宽松。怎样进一步利用这些资源,增强调度自动化系统的功能,是调度自动化系统实用化工作开展以后的一项具体工作。本文介绍了利用计算量点,完成实时线损变损计算、电容器投切容量和统计分析、功率因数计算、遥测数据精度自动监测和有功无功电流相关计算等应用功能的情况。 展开更多
关键词 调度自动化系统 计算量点 线损 电力系统
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一种在异构系统中实现负载平衡的方法 被引量:9
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作者 金之雁 王鼎兴 《应用气象学报》 CSCD 北大核心 2003年第4期410-418,共9页
提出了在异构系统实现负载平衡的区域分解算法和实现负载平衡的计算方法 ,利用它的负反馈性质解决了异构系统处理机计算速度测量误差造成的负载测量不准问题 ,并对处理机速度变化 ,速度测量误差、处理机数量、网格点计算量的分布等因素... 提出了在异构系统实现负载平衡的区域分解算法和实现负载平衡的计算方法 ,利用它的负反馈性质解决了异构系统处理机计算速度测量误差造成的负载测量不准问题 ,并对处理机速度变化 ,速度测量误差、处理机数量、网格点计算量的分布等因素的影响进行了计算 ,结果表明本方法具有很强的平衡负载能力和较强的适应性 ;根据计算结果提出了解决模式网格点计算量不易测量问题的解决方案 ,并用扩散方程和模拟物理过程进行试验 ,试验表明这种方法是可行的 。 展开更多
关键词 异构系统 负载平衡 区域分解算法 负反馈性质 速度测误差 处理机数 网格计算 数值天气预报
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A Trusted Attestation Mechanism for the Sensing Nodes of Internet of Things Based on Dynamic Trusted Measurement 被引量:10
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作者 Bei Gong Yubo Wang +2 位作者 Xiangang Liu Fazhi Qi Zhihui Sun 《China Communications》 SCIE CSCD 2018年第2期100-121,共22页
Internet of things has been widely applied to industrial control, smart city and environmental protection, in these applica- tion scenarios, sensing node needs to make real-time response to the feedback control of the... Internet of things has been widely applied to industrial control, smart city and environmental protection, in these applica- tion scenarios, sensing node needs to make real-time response to the feedback control of the application layer. Therefore, it is nec- essary to monitor whether or not awareness nodes are trusted in real time, but the existing mechanisms for trusted certification lack the real-time measurement and tracking of the sensing node. To solve the above problems, this paper proposes a dynamic metric based authentication mechanism for sensing nodes of Internet of things. Firstly, the dynamic trustworthiness measure of the sensing nodes is carried out by introducing the computational function such as the trust function, the trust- worthiness risk assessment function, the feed- back control function and the active function of the sensing node. The dynamic trustworthi- ness measure of sensing nodes from multiple dimensions can effectively describe the change of trusted value of sensing nodes. Then, on the basis of this, a trusted attestation based on node trusted measure is realized by using the revocable group signature mechanism of local verifier. The mechanism has anonymity, un- forgeability and traceability, which is proved the security in the standard model. Simulationexperiments show that the proposed trusted attestation mechanism is flexible, practical and ef|Scient and has better attack resistance. It can effectively guarantee the reliable data transmission of nodes and realize the dynamic tracking of node reliability, which has a lower impact on system performance. 展开更多
关键词 internet of things: trusted mea-surement trusted attestation: group signature
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Semi-empirical modeling of volumetric efficiency in engines equipped with variable valve timing system 被引量:1
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作者 Mostafa Ghajar Amir Hasan Ka Kaee Behrooz Mashadi 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第12期3132-3142,共11页
Volumetric efficiency and air charge estimation is one of the most demanding tasks in control of today's internal combustion engines.Specifically,using three-way catalytic converter involves strict control of the ... Volumetric efficiency and air charge estimation is one of the most demanding tasks in control of today's internal combustion engines.Specifically,using three-way catalytic converter involves strict control of the air/fuel ratio around the stoichiometric point and hence requires an accurate model for air charge estimation.However,high degrees of complexity and nonlinearity of the gas flow in the internal combustion engine make air charge estimation a challenging task.This is more obvious in engines with variable valve timing systems in which gas flow is more complex and depends on more functional variables.This results in models that are either quite empirical(such as look-up tables),not having interpretability and extrapolation capability,or physically based models which are not appropriate for onboard applications.Solving these problems,a novel semi-empirical model was proposed in this work which only needed engine speed,load,and valves timings for volumetric efficiency prediction.The accuracy and generalizability of the model is shown by its test on numerical and experimental data from three distinct engines.Normalized test errors are 0.0316,0.0152 and 0.24 for the three engines,respectively.Also the performance and complexity of the model were compared with neural networks as typical black box models.While the complexity of the model is less than half of the complexity of neural networks,and its computational cost is approximately 0.12 of that of neural networks and its prediction capability in the considered case studies is usually more.These results show the superiority of the proposed model over conventional black box models such as neural networks in terms of accuracy,generalizability and computational cost. 展开更多
关键词 engine modeling modeling and simulation spark ignition engine volumetric efficiency variable valve timing
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Exact Calculations of Vertex ^-sγb and ,^-sZb in the Unitary Gauge
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作者 WU Lu-Sen XIAO Zhen-Jun 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第3X期502-508,共7页
In this paper, we present the exact calculations for the vertex ^-sγb and ^sZb in the unitary gauge. We find that (a) the divergent- and μ-dependent terms are left in the effective vertex function Г^γμ(p, k) ... In this paper, we present the exact calculations for the vertex ^-sγb and ^sZb in the unitary gauge. We find that (a) the divergent- and μ-dependent terms are left in the effective vertex function Г^γμ(p, k) for b → sγ transition even after we sum up the contributions from four related Feynman diagrams; (b) for an on-shell photon, such terms do not contribute et al.; (c) for off-shell photon, these terms will be canceled when the contributions from both vertex ^sγb and ^sZb are taken into account simultaneously, and therefore the finite and gauge-independent function Zo(xt) = Co(xt) + Do(xt)/4, which governs the semi-leptonic decay b → sl^- l^+, is derived in the unitary gauge. 展开更多
关键词 unitary gauge Feynman diagram VERTEX
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Linear and Nonlinear Optical Absorptions of a Hydrogenic Donor in a Quantum Dot Under a Magnetic Field 被引量:3
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作者 XIE Wen-Fang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第5期923-926,共4页
The linear and nonlinear optical properties of a hydrogenic donor in a disc-like parabolic quantum dot in the presence of an external magnetic field are studied. The calculations were performed within the effective ma... The linear and nonlinear optical properties of a hydrogenic donor in a disc-like parabolic quantum dot in the presence of an external magnetic field are studied. The calculations were performed within the effective mass approximation, using the matrix diagonalization method and the compact density-matrix approach. The linear and nonlinear optical absorption coefficients between the ground (L =0) and the first excited state (L = 1) have been examined based on the computed energies and wave functions. We find that the linear, nonlinear third-order, and total optical absorption coefficients are strongly affected by the confinement strength of QDs, the external magnetic field, and the incident optical intensity. 展开更多
关键词 quantum dot nonlinear optics
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Connecting Wind Turbine Generator to Distribution Power Grid--A Preload Flow Calculation Stage
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作者 Agbetuyi Ayoade Felix Awosope Cladius Ojo Aremu Awelewa Ayokunle Ajibola Adoghe Uwakhonye Anthony Odigwe Ani Ishioma Samuel Adekunle Isaac 《Journal of Energy and Power Engineering》 2014年第10期1811-1815,共5页
A distribution grid is generally characterized by a high R/X (resistance/reactance) ratio and it is radial in nature. By design, a distribution grid system is not an active network, and it is normally designed in su... A distribution grid is generally characterized by a high R/X (resistance/reactance) ratio and it is radial in nature. By design, a distribution grid system is not an active network, and it is normally designed in such a way that power flows from transmission system via distribution system to consumers. But in a situation when wind turbines are connected to the distribution grid, the power source will change from one source to two sources, in this case, network is said to be active. This may probably have an impact on the distribution grid to whenever the wind turbine is connected. The best way to know the impact of wind turbine on the distribution grid in question is by carrying out load flow analysis on that system with and without the connection of wind turbines. Two major fundamental calculations: the steady-state voltage variation at the PCC (point of common coupling) and the calculation of short-circuit power of the grid system at the POC (point of connection) are necessary before carrying out the load flow study on the distribution grid. This paper, therefore, considers these pre-load flow calculations that are necessary before carrying out load flow study on the test distribution grid. These calculations are carded out on a test distribution system. 展开更多
关键词 Distribution grid power quality wind turbine generator load flow.
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A New Alternative Method for Checking Total Stations
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作者 Nikolitsas Konstantinos 《Journal of Civil Engineering and Architecture》 2015年第1期114-120,共7页
Today, just by activating a button on the display panel of a total station, one can measure horizontal and vertical angles or calculate distances and coordinates of points. For this reason, it has become necessary to ... Today, just by activating a button on the display panel of a total station, one can measure horizontal and vertical angles or calculate distances and coordinates of points. For this reason, it has become necessary to improve the check of a total station in order to respond to its contemporary way of use. The aim of this research is to create a new method for checking total stations using only one check--field, in a different way of the today's standards. The basic principle, of the comparison of an instrument's measurements to those of another instrument with higher accuracy, is implemented into a mathematical model such as the adjustment of an indoor geodetic network. Thus, the check of the proper function of a total station is applied. An a-priori calculation Of^o of the network's adjustment can be calculated by modeling the uncertainties using statistical methods as the random number generators by means of the Monte Carlo method. The prospective ao can then be compared to the a-posteriori ao provided by the adjustment of the measurements which are carried out by using the total station under check. 展开更多
关键词 Single control network geodetic network Monte Carlo techniques.
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Research on the Influence of X-ray Phase Contrast Imaging Parameters with Micro-focus Source
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作者 WU jie WANG Yan +3 位作者 CHEN Jia-bi CHENG Jing-hai ZHANG Xue-long NIE Sheng-dong 《Chinese Journal of Biomedical Engineering(English Edition)》 2011年第1期29-35,共7页
X-ray in-line phase contrast imaging enables weakly to absorb specimens to be imaged successfully with high resolution and definition. In this paper we use computer simulation method to analyze how each parameter infl... X-ray in-line phase contrast imaging enables weakly to absorb specimens to be imaged successfully with high resolution and definition. In this paper we use computer simulation method to analyze how each parameter influences the quality of the image. It can avoid wasting unnecessary time and materials in the course of experiment to get ideal images. 展开更多
关键词 X-ray phase contrast micro-focus source SIMULATION
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A brief review on Majorana bound states in topological superconductors 被引量:1
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作者 Rui Lin Zhi Wang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2016年第7期1-8,共8页
Topological superconductivity has drawn much attention recently, and most interests are focused on the Majorana bound states existing at the edges of one-dimensional topological superconductors. These Majorana bound s... Topological superconductivity has drawn much attention recently, and most interests are focused on the Majorana bound states existing at the edges of one-dimensional topological superconductors. These Majorana bound states are ideal platform for studying non-Abelian statistics. Meanwhile, they are proposed to be useful in quantum computation. In this review, we introduce the basic concepts and models in this area. We begin from the Kitaev model, which is the most concise model for one-dimensional topological superconductivity. Then, we discuss how to realize this model with spin-orbit coupling in realistic materials. Finally, we show some simple methods to detect the Majorana bound states and study their novel properties with the help of adjacent quantum dots. 展开更多
关键词 topological superconductor Kitaev model quantum dot
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Digital Analysis of the Water Layout Ecological Wisdom in Traditional Chinese Rural Settlements:A Case Study of Liukeng Village in Jiangxi Province 被引量:6
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作者 LI Zhe HUANG Si +1 位作者 WANG Han LI Yan 《Journal of Resources and Ecology》 CSCD 2022年第3期371-381,共11页
During the long-term construction and development process of eliminating water disasters and promoting water conservancy in traditional settlements,a set of mature strategies that have simple ecological wisdom in wate... During the long-term construction and development process of eliminating water disasters and promoting water conservancy in traditional settlements,a set of mature strategies that have simple ecological wisdom in water layout have been formed by adapting to the natural water environment and utilizing the regional water system.This study conducted a qualitative and quantitative analysis of the water layout strategies and their effects on Liukeng Village from three aspects:deciphering the water systematic pattern,calculating the spatial characteristics and quantifying the water environment,to explore the technical assistance and potential of water layout research in traditional rural settlements.The results indicated that Liukeng has an unambiguously systematic water layout pattern of source diversion,middle drainage and end purification of the water.Through 3D point cloud computing,it was shown that the site selection made accurate use of micro-topography and adopted the strategy of a multi-source water management.It formed an organic water system pattern,which provided sufficient water sources for all kinds of needs of Liukeng Village.The Dragon Lake in Liukeng held 83.0%of the precipitation,and the vegetation area accounted for 34.7%of the total area of Liukeng,which had high surface permeability and good middle drainage effects.Water detection showed that the Dragon Lake provided good water quality and purification.The purposes of this study are to fill the gap in previous non-quantitative research on water layout in traditional rural settlements,excavate the hidden information and value of settlements,and deepen our understanding of the ecological wisdom of the overall planning,layout and construction of water conservancy in traditional rural settlements.This knowledge can assist the win-win situation of water conservancy cultural heritage protection and modern utilization.It also provides useful inspiration and reference for properly dealing with the problems of rain and flooding,realizing the sustainability of water resources,and protecting the ecological environment in the process of the development and construction of village settlements in China. 展开更多
关键词 ecological wisdom of water layout water systematic pattern 3D point cloud computing quantification of water environment water conservancy heritage
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Patterning Nanoroads and Quantum Dots on Fluorinated Graphene 被引量:2
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作者 Morgana A. Ribas Abhishek K. Singh +1 位作者 Pavel B. Sorokin Boris I. Yakobson 《Nano Research》 SCIE EI CAS CSCD 2011年第1期143-152,共10页
Using ab initio methods we have investigated the fluorination of graphene and find that different stoichiometric phases can be formed without a nucleation barrier, with the complete "2D-Teflon" CF phase being thermo... Using ab initio methods we have investigated the fluorination of graphene and find that different stoichiometric phases can be formed without a nucleation barrier, with the complete "2D-Teflon" CF phase being thermody- namically most stable. The fluorinated graphene is an insulator and turns out to be a perfect matrix-host for patterning nanoroads and quantum dots of pristine graphene. The electronic and magnetic properties of the nanoroads can be tuned by varying the edge orientation and width. The energy gaps between the highest occupied and lowest unoccupied molecular orbitals (HOMO-LUMO) of quantum dots are size-dependent and show a confinement typical of Dirac fermions. Furthermore, we study the effect of different basic coverage of F on graphene (with stoichiometries CF and C4F) on the band gaps, and show the suitability of these materials to host quantum dots of graphene with unique electronic properties. 展开更多
关键词 GRAPHENE fluorinated graphene fluorographene nanoroads quantum dots
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Effects of hydrostatic pressure and external electric field on the impurity binding energy in strained GaN/Al_xGa_(1-x)N spherical quantum dots 被引量:2
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作者 达来木仁 闫祖威 石磊 《Optoelectronics Letters》 EI 2012年第3期224-228,共5页
The binding energy and Stark effect energy shifts of a shallow donor impurity state in a strained GaN/AlxGa1-xN spherical finite-potential quantum dot (QD) are calculated using a variational method based on the effect... The binding energy and Stark effect energy shifts of a shallow donor impurity state in a strained GaN/AlxGa1-xN spherical finite-potential quantum dot (QD) are calculated using a variational method based on the effective mass approximation. The binding energy is computed as a function of dot size and hydrostatic pressure. The numerical results show that the binding energy of the impurity state increases, attains a maximum value, and then decreases as the QD radius increases for any electric field. Moreover, the binding energy increases with the pressure for any size of dot. The Stark shift of the impurity energy for large dot size is much larger than that for the small dot size, and it is enhanced by the increase of electric field. We compare the binding energy of impurity state with and without strain effects, and the results show that the strain effects enhance the impurity binding energy considerably, especially for the small QD size. We also take the dielectric mismatch into account in our work. 展开更多
关键词 Binding energy Electric fields GALLIUM Hydrostatic pressure Semiconductor quantum dots
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