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To reduce the cost of energy of offshore wind energy conversion, large individual wind turbines of 10 MW or higher power levels are drawing more attention and expected to be desirable. Conventional wind generator systems would be rather large and costly if scaled up to 10 MW. Direct drive superconducting generators have been proposed to reduce the generator size, because the electrical machines with...
Large wind turbines of 10 MW or higher power levels are desirable for reducing the cost of energy of offshore wind power conversion. Conventional wind generator systems will be costly if scaled up to 10 MW due to rather large size and weight. Direct drive superconducting generators have been proposed to address the problem with generator size, because the electrical machines with superconducting windings...
We consider a large-scale cognitive radio network (CRN) in a Rayleigh fading environment. Errors of spectrum sensing by secondary users (SUs) are considered in the letter. Cumulative inter-network interference (between primary and secondary networks) is calculated and outage probability of primary users (PUs) is derived in the closed-form. The upper and lower bounds on the percolation area are obtained...
In the era of cloud computing, there are many correlated images in the cloud, joint compression of these images may provide much higher compression ratio than individual coding. Model-based coding is an appealing approach to image coding in the cloud, as it removes knowledge redundancy among images that share the same model. In this paper, we make an attempt to model-based image coding for landmark...
For the researches of Extended Interaction Oscillator (EIO) with frequency exceed 300GHz, the parameters of high frequency structure are optimum with a help of CST studio. The parameters including width of waveguide, the length of waveguide, the height of waveguide, the number of periodic structure, the radius of electron beam tunnel and the thickness of metal between nearby waveguide are studied...
This paper proposes a novel approach to faulty phase selection using S-transform and phase current integration for the fast transmission line protection. The paper analyzes the modulus characteristics of various types of fault and the characteristics of phase current for two phases to ground fault. On the basis of it, the phase selection algorithm first uses S-transform to get single frequency phasor...
It has been more challenging to monitor and control plenty of DERs (Distribution Energy Resources) when interconnected to distributed networks continuously. The ADN (Active Distributed Network) with hierarchical zoning control mode provides a way to monitor and control quantities of DERs effectively and efficiently. The EMS of ADN (ADMS, Active Distribution Network Energy Manager System) communicates...
Confidential power supply and storage capacity (CPSSC) is the random variable of the power supply and storage capacity (PSSC). Its probability distribution is related to power and capacity of energy storage and probability distribution of uncontrollable DG and load in the autonomous regions. Its distribution function and density function can be derived by cumulant method and Gram-Charlier series expansion...
Active distribution network (ADN), which is characterized by high penetration of distributed generation (DG) has often appeared reverse power across voltage grades, which leads to unsafe operation. In this paper, ADN is divided into regions based on switches location and region consumption capacity is proposed to obtain regional power flow from now on period of time by using ultra-short-term forecasting...
With the reform of electrical market, the application of demand-side management or demand response has been widely researched. The large elasticity of electricity price enables a more flexible control strategy in load-side. In this paper, the basic features of flexible loads including continuous and discrete loads or interruptible or not-interruptible loads will be analysed and modelled. Besides,...
As a software organization grows and becomes more sophisticated by business growing and solution upgrading, it recognizes the need for Quality Assurance to support their development process and improve the quality of system. The software quality control, quality planning, and quality assessing is a basic concept of the software engineering and its practice. That means the software quality should be...
Caching popular contents at the base station (BS) can reduce the end-to-end delay of service and the cost of cellular networks. Yet it is unknown whether introducing cache to BS can improve the energy efficiency (EE) of downlink systems. With BS caching, energy consumption for backhauling can be reduced, but caches will also consume energy. In this paper, we analyze the EE of two kinds of networks...
In order to solve the problems of LEACH (Low Energy Adaptive Clustering Hierarchy) nodes short life cycle and consumption imbalance, the paper proposes an improved algorithm of LEACH. The main idea of the improved algorithm is to consider the current position and the current energy of the node, which can be more evenly distributed cluster head, in order to prolong the life cycle of the node. A comparison...
Magnetic induction (MI) is a promising technique for communications in the very harsh propagation conditions like underground or underwater, etc. In this paper we investigate the connectivity issue of MI ad hoc networks deployed in a three-dimensional space. The transmitting distance of MI covers a quasi- ellipsoid space other than a standard sphere space in a traditional wireless propagation case...
In this paper, an on-board charger for electric vehicle, with two-stage power converter, is designed. Firstly, a single-phase Boost-APFC (Active Power Factor Correction) circuit controlled by a one-cycle controller is designed as the front state converter. Compared to the traditional APFC circuit, the One-cycle controller is constructed without considering the multiplier and AC line voltage sensing...
Collaborative filtering (CF) predicts user preferences in item selection based on the known user ratings of items. As one of the most common approach to recommender systems, CF has been proved to be effective for solving the information overload problem. CF can be divided into two main branches: memory-based and model-based. Most of the present researches improve the accuracy of Memory-based algorithms...
Image compression had been extensively studied for reducing coding rate yet producing acceptable visual quality. However, there are many application scenarios where the compressed images are used for automatic recognition rather than human viewing, thus the visual quality is no longer critical for compression. SIFT features have demonstrated their utility in many recognition scenarios and SIFT-preserving...
How to make dynamic recommendations under volatile user interest drifts has been a problem of great interest in modern recommender systems, where challenges lie in accurate and efficient measurement, modeling, and prediction of the user interest drifts. This paper studies a category-based approach to the problem with the key idea that items are aggregated into categories and recommendations are made...
A digital one-cycle control strategy combined with the Quasi Proportional Resonant (QPR) controller is applied to the three-phase grid-connected inverter with LCL filter in this paper. The control system contains dual loops with inner loop of capacitive current and outer loop of net current. Instead of conventional SPWM modulation method, one-cycle control for the inner loop has functions of control...
Magnetic Induction (MI) is a through-the-earth (TTE) communication technique which can accomplish reliable wireless propagation with long distance. When used in underground mines, MI-based transmit distance is limited by several factors: high path loss, limited size for transmitter antenna due to the narrow underground space, and limited transmitting power due to anti-explosion regulations. In this...
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