The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Ionosphere is an important space environment near the earth. Its disturbance would result in severe propagation effects to radio information system, thus causing bad influences on communication, navigation, radar and so on. The total electron content (TEC) is an important parameter to present the disturbance of ionosphere, so TEC forecast is very meaningful in scientific research field. In this paper,...
This paper makes the first attempt to utilize convolutional neural network (CNN) for classification of solar radio spectrums. The solar radio spectrum is a two-dimensional gray-scale image with one dimension of frequency and the other of time. Taking the advantages of CNN, we can efficiently learn the distinct characteristic of different types of spectrum, and further classify them even more accurate...
An i-vector has become the state-of-the-art algorithm for text-independent recognition. Most of related works take the extraction of the i-vector as a black-box by using some open software (e.g. Kaldi, Alize) and focus on the vector-based back-end algorithms, such as length normalization, WCCN, or PLDA. In this paper, we study the variational method and present a concise derivation for the i-vector...
This paper develops a system to automatically distinguish natural speech from synthetic speech. The issue of feature selection is considered. We take commonly used feature Mel-Frequency Cepstrum Coefficient (MFCC) in consideration, as well as other features such as Relative Phase Shift (RPS) and pitch tuned for Automatically Speech Recognition (ASR). We found some features are complimentary in the...
Human factors have attracted more and more attention in software engineering. Of many kinds of developer metrics proposed, developer quality is important. Recently, some researchers measure a developer's quality as the rate of his/hernon bug-introducing commits. In this paper, we conduct an empirical study of this developer quality metric. We use the data of six open source software projects and get...
Bug fixing is one of the most important activities in software development and maintenance. A software project often employs an issue tracking system such as Bugzilla to store and manage their bugs. In the issue tracking system, many bugs are invalid but take unnecessary efforts to identify them. In this paper, we mainly focus on bug fixing rate, i.e., The proportion of the fixed bugs in the reported...
In this paper, a novel embedded voltage clamping structure is proposed for an IGBT module. Firstly, the negative effect of loop inductances in the voltage clamping circuit is analyzed. And then, a novel embedded structure is proposed to minimize the parasitic inductances in the voltage clamping loop. Finally, an experiment is carried out on an IGBT module. With the proposed embedded structure, the...
In this paper, a universal voltage clamping circuit for the T-type neutral-point-clamped (TNPC) converter is introduced. It is shown that, for any TNPC implementation, the proposed voltage clamping circuit can well suppress all voltage spikes of power devices at the switching transients. Therefore, the devices can operate in a much safer region.
This paper presents a precise and cost-effective capacitor-based current balancing scheme for multiple LED strings application. Using capacitor's Ampere-Second balance characteristic, the precise current balancing of N LED Strings can be achieved by N−1 Capacitors. Besides, an auto-restart scheme is also presented in this paper to achieve the open circuit protection and to automatically restart the...
This article designed a remote control system, which brought in a network server that integrated most of the functions of the end terminals. The system is easy to update and maintain. As 4G becomes popular, the system will be more and more suitable for personal or industrial use.
With the rapid development of the network and the communication technologies, the demand for wireless communication is increasing. In recent years, short-range wireless communication had a rapid development and application in all aspects because of its advantages. This paper, as the aircraft model' remote control system for a example, briefly introduced how to achieve short-range wireless communication...
In this paper, based on ZigBee technology and GPRS a wireless remote and detecting system for smart home is developed which realized the detecting of the home equipment and the state of home environment. The system consists of the host control centre and several sub function modules and software. The host control system includes MC39i module, CC2430 module and STC12C5410 MCU control center. The several...
The electrode temperature has strong influence on the lifetime of HID lamps. The 800 nm spectral radiance distribution of a HID lamp electrode in a quartz arc tube were measured with a monochromator, which was calibrated with a tungsten ribbon spectral radiance standard lamp. Then the electrode temperature was calculated using Planck formula. The dependence of electrode temperature on time, rectangular...
This paper introduces the intelligent home appliance control system, the system is developed through ARM microprocessor, embedded Linux operating system, ZigBee wireless communication technology and network technology. It gives the overall framework of hardware and software design, and describes ways to implement the system. User can control appliances through hand-held mobile terminal.
This paper presents a new model for electrodes of fluorescent lamps with constant RMS voltage heating, in order to predict the electrodes’ characteristic ratio of hot-to-cold resistance ( / ) during the preheating phase, which is related to both the preheating time and the RMS value of voltage across the lamp electrodes. In developing this model, we first analyzed a simple test platform, to...
A design of High-frequency isolation grid-connected PV inverter is introduced, the design uses the method of secondary structure, front-end isolation. This paper describes the basic design, key technology and control strategies of it. A test device was completed to verify that the program meets the design requirements.
In traditional grid-connected PV system, it's hard to remove failure of individual PV panels. This paper presents a Solar PV Grid-Connected Micro-inverter which can be embedded in a single stand-alone photovoltaic panel to solve the problem of single point of failure. For a single photovoltaic panel, rated power of the Micro-inverter is 220W, using the topology of interleaved flyback converter.
Ground source Heat Pump(GSHP) is becoming the more and more focus of the world's attention as a HVAC technique of energy saving and environment protection. This paper first introduced the experiment for Ground-Source water/water Heat Pump. The heat transfer model of underground heat exchanger was introduced, and established predication modeling using neural network. From the computer simulation results,...
This paper researched on KEELOQ algorithm and presented a wireless anti-theft system based on the KEELOQ technology. The system has one central controller and no more than eight monitors. When the whole wireless anti-theft system were designed, a physical testing about one hundred days was made. The results showed that the system works stably.
With explosive increasing of capacity in optical networks, XFP optical transceivers are widely employed. In this paper, an application of the optical transceivers with real-time diagnosis function in 40Gbit/s Polarization-Multiplexed Differential Quadrature Phase Shift Keying (PM-DQPSK) system was designed and realized. What's more, the electrical signal 10Gbit/s from XFP optical transceiver is too...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.