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The multilevel converter is a prospective topology for both Medium Voltage and High Voltage Direct Current (HVDC) applications. In high power application, the forward topology is applied to increase the power region. In this paper, a novel forward-mode five-level inverter is presented which combines the features of the conventional multilevel converters and forward topology. The converters can transfer...
The digital control power supply has been widely used by virtue of its many advantages. However, it may cause limit cycle oscillations due to quantization in the feedback loop when the switching frequency is high. This paper presents an analytical model of buck converter using state space average method and derives the equilibrium expression in steady state, and the requirement for DPWM resolution...
For the rationality of optimization of 126kV SF6 circuit breaker opening and closing, it calculates and analyzes the matching characteristics of circuit breaker and motor drive mechanism. And then, the corresponding relationship between the contact movement and the permanent magnet motor is obtained. The contact speed of circuit breaker is mainly determined by the rotation speed of permanent magnet...
The permanent magnet direct-driven motor for high voltage circuit breaker should not only meet the requirements of the speed, high starting torque and dynamic response ability, but also to meet the mechanical life requirements of the operation. In this paper, a new type of permanent magnet synchronous motor based on V-type structure is presented. It is shown by theoretical analysis and parameters...
With the rapid development of social security service, people have higher demands for medical service. Therefore, it is the development direction of mobile medical construction to build humanized and personalized service concepts. Mobile Health is of great significance to the society and health. Because of the slow running and unsupported distribution, the traditional computer can't solve the current...
For the field of weak magnetic anomaly measurement, a high precision three axis fluxgate magnetometer MAG-XYZ is designed, which has a wide dynamic measurement range (0∼ + 100000nT), high measurement accuracy (24-bit analog-to-digital converter) and 2K Hz sampling rate. The basic working principle of FGM3D / 100 sensor is described, and the composition of the three axis fluxgate magnetometer is introduced...
We optimized micro-holes in a thin slab for fast Si photodetectors at wavelength 800–950nm. Lateral modes are shown to be responsible for the effective light trapping. Small disorder and cone hole shapes helped achieve uniform quantum efficiency in a wide wavelength range.
Argument Component Boundary Detection (ACBD) is an important sub-task in argumentation mining; it aims at identifying the word sequences that constitute argument components, and is usually considered as the first sub-task in the argumentation mining pipeline. Existing ACBD methods heavily depend on task-specific knowledge, and require considerable human efforts on feature-engineering. To tackle these...
Argumentation mining aims at automatically extracting the premises-claim discourse structures in natural language texts. There is a great demand for argumentation corpora for customer reviews. However, due to the controversial nature of the argumentation annotation task, there exist very few large-scale argumentation corpora for customer reviews. In this work, we novelly use the crowdsourcing technique...
In this paper, an LLC resonant converter design methodology for battery charger based on mode analysis is presented. The accuracy of DC gain curve obtained by mode analysis is much higher than that by FHA. Conduction loss and switching loss can be minimized by reasonably configuring charging trajectory on the mode distribution map. ZVS and ZCS can be realized during whole charging process. Finally,...
In order to study wind power medium-term forecast method, a combined forecasting method is proposed in this paper, taking gray theory and neural network to combine to forecast wind power of wind farm. Through establishing metabolism gray forecast model, using the linear weighted method to take gray information metabolism model and chaotic neural network model for portfolio optimization, and simulated...
Most recent CNN architectures use average pooling as a final feature encoding step. In the field of fine-grained recognition, however, recent global representations like bilinear pooling offer improved performance. In this paper, we generalize average and bilinear pooling to “α-pooling”, allowing for learning the pooling strategy during training. In addition, we present a novel way to visualize decisions...
Photosynthesis is the basis of biological survival. Traditional methods are complicated, time consuming and destruction of the sample. Variable chlorophyll a fluorescence techniques provide a rapid, sensitive and non-invasive measurement of the photosynthetic physiology of algae. Based on this technique, an in situ measurement system of photosynthetic activity (Fv/Fm) was established, using blue LEDs...
In this paper, the design and simulation of the high voltage switchgear are discussed, the current situation and existing problems of high voltage switchgear are expounded, developed a design that can solve the problem, fully meet the portable requirements of the measurement system, the installation method of ground wave sensor based on ultrasonic / ground wave cable partial discharge detection system...
A modular-multilevel (MMC) DC/DC converter is proposed in this paper, which can be deployed to inter-connect DC grid of different voltage levels, especially in the new energy sources such as wind power and solar power grid connection. Its key features include: 1) step-up and step-down operation. 2) bidirectional power flowing. 3) bi-directional fault blocking similar to a DC breaker. The operation...
Active depth cameras suffer from several limitations, which cause incomplete and noisy depth maps, and may consequently affect the performance of RGB-D Odometry. To address this issue, this paper presents a visual odometry method based on point and line features that leverages both measurements from a depth sensor and depth estimates from camera motion. Depth estimates are generated continuously by...
A new metaheuristic intelligent algorithms—flower pollination algorithm (FPA) and a novel differential evolution mutation strategy—Target Mutation(TM) strategy are introduced. An improved FPA based on mutation strategy—MFPA algorithm, is proposed to overcome the low accuracy computation, low speed convergence, and easy to fall into local optimization. The MFPA improves the TM, and introduces the strategy...
There is enormous visitation pressure in most cloud systems, which is why they require so many devices and have such enormous structures. This pressure and size is accompanied by a huge cost problem. Enterprise IT departments must decide whether to build a private cloud themselves or lease space in a public cloud instead. To add to the complexity, most enterprise cloud systems are hybrids simultaneously...
The recognition of impassable terrain in three dimension environment plays an important role in the motion planning of mobile robot. However, the most common used sensor like range finders, stereo vision sensors, which can provide the clues of the surrounding environment suffer from their inaccurate nature. Thus, this paper proposed a rapid impassable terrain recognition algorithm based on hypotheses...
Robust perception-action models should be learned from training data with diverse visual appearances and realistic behaviors, yet current approaches to deep visuomotor policy learning have been generally limited to in-situ models learned from a single vehicle or simulation environment. We advocate learning a generic vehicle motion model from large scale crowd-sourced video data, and develop an end-to-end...
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