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In this paper, AlGaN/GaN heterostructure high electron mobility transistors (HEMTs) have been fabricated on GaN-on-Si substrate. These devices were studied for the application of the 5th generation (5G) wireless communication. The geometric parameters such as gate length (Lg), cap length (Lcap) and gate-to-source distance (Lgs) are optimized so that the cut-off frequency reaches 38.8 GHz. It is found...
As a representation of information, Multi-dimension network is more and more popular, such as web data and social network. With the increment of data source, the entities of the network become diverse. How to analyze these multi-dimensional heterogeneous networks effectively and efficiently is a big challenge. In this paper, we propose a Two-Step Multi-dimensional Heterogeneous (TSMH) Graph Cube framework...
We propose a community detection method based on K-shell. Our method determines some core nodes of the graph according to the K-shell value of these nodes. These core nodes constitute a subgraph on which we use the community detection algorithm to divide the core nodes into communities. Compared to classical methods, by this way, our proposed method removes the non-core nodes which may impact the...
Functional load (FL) is the quantitative measure of the importance of phonological contrasts, which stand for the differentiation of communicative linguistic units. Correct estimate of FLs is useful for the studies of speech recognition, language evolution, language teaching and etc. Conventional approaches use phonological transcriptions and unigram probabilities for the estimation, hence weak in...
Microblogs play an important role in online social communications. Different from ordinary pieces of information, some hot topics and emerging news will become much more popular in a very short time with the help of this information spreading platform of microblogs. In these "super spreading events", messages are transmitted to a vast range of individuals through a small portion of users...
The description of the wave propagation in the multilayer adhesive structure under different forms of interfaces is very complex. For this issue, the reflection and transmission coefficient expressions of longitudinal and transverse waves with the dimensionless parameter ofÉÄ in the trilaminar plate-like adhesive structure are derived when the adhesive layer is assumed to be viscoelastic material...
Much of the data of scientific interest, particularly when independence of data is not assumed, can be represented in the form of networks where data nodes are joined together to form edges corresponding to some kind of associations or relationships. Such information networks abound, like protein interactions in biology, web page hyperlink connections in information retrieval on the Web, cellphone...
In this paper, finite control-set model predictive control of two-level and three-level four-leg voltage source converters (VSCs) is presented. The predictive current control (PCC) and predictive voltage control (PVC) schemes are presented considering grid-connected and standalone distributed generation applications respectively. The discrete-time model of load currents, load voltages, DC-link capacitors...
The renewable energy sources are become an alternative for conventional power generating stations. Currently, in Canada 16.9% of total primary energy supply is met by the renewable energy sources. However, there is an increasing concern over renewable energy sources in power system due to its highly intermittent nature. This may cause problems such as stability, voltage regulation and other power...
This work proposes a Model Predictive Control (MPC) strategy for Cascaded H-Bridge (CHB) converters under unbalanced power generation among each converter phase. Therefore, the control target is to extract unbalanced power from the dc-sources while providing balanced power to the grid. The key novelty of this proposal lies in the way the unbalanced power generation issue is explicitly considered into...
This paper focuses a novel Zero Current Switched (ZCS) back-to-back current source converter for high power applications. A single DC link auxiliary circuit with a new commutation scheme helps to achieve soft switching for rectifier, inverter side and auxiliary switches. Two different switching algorithm (namely, Type-I and Type-II) are proposed depending upon the relative switching instants of rectifier...
Leakage current reduction is one of the most important issues for transformerless PV grid-connected inverters. Many interesting single-phase topologies have been reported to reduce the leakage currents. However, three-phase PV inverter topologies with reduced leakage currents are not received much attention. In this paper, a new family of three-phase topology is proposed to reduce the leakage current...
This paper presents a novel seven-level converter for medium-voltage high-power applications. The proposed converter is based on the upgrade of the four-level nested neutral-point clamped (NNPC) converter. This converter has less number components compared to the classic seven-level converters and can operate over a wide range of voltages (2.4–7.2kV) without the need for connecting power semiconductor...
The high penetration level of power electronics interfaced Distributed Generation (DG) systems creates great ancillary services potential through the DG interfacing converters (IFCs) such as the grid unbalanced voltage compensation. However, the unbalanced voltage compensation may cause adverse effects on the IFCs' operation such as output active power oscillation and DC link voltage variations. Moreover,...
Concepts and characteristics of Space Information Network (SIN) is introduced in this paper. The idea that Beidou global navigation constellation is the promising backbone network of SIN is proposed. Aiming at this constellation, this paper probes into Doppler characteristics of inter satellite links (ISLs) between two satellites located in different orbit plants, including Doppler frequency-shift,...
A “nuclear power plant robot” is introduced in this paper. It is developed by Shanghai University. Boss is chosen for testing obstacle surmounting capability of tracked mobile robot with 6-DOF. There are two swinging arms in the front of the robot and two in the rear, they can swing synchronously, respectively. The movement posture during the boss-climbing are discussed. As the poses of the arms change,...
With the rapid development of Web2.0, more and more people like to show their life or opinions on social media websites or forums, such as Weibo, Twitter and Tianya, which produce masses of short texts. In order to manage these short texts effectively, Short Text Classification becomes an important branch of Text Classification. However, because of the short text length, the lack of signals, and the...
Artificial Neural Networks (ANNs) are widely used in various practical problems about time series. In this paper, a methodology based on exogenous series is used in combination with a Back Propagation (BP) neural network to predict time series. Exogenous series is chosen by correlation theory with endogenous series. In this way, the prediction output is obtained by not only the historical data but...
Resource prediction is the basis of resource allocation and task scheduling in cloud platform. Different from previous research which takes a server as the research object, we mainly study resource prediction based on program granularity and provide a resource prediction model. A program will cost Central Processing Unit (CPU), memory and I/O when it is executing. To predict these three kinds of resources,...
In this paper, we revisit a video steganalytic scheme using the motion vector reversion-based (MVRB) feature, and make necessary improvements. Since been proposed, MVRB feature has shown its effectiveness in detecting typical motion vector-based steganographic schemes. However, as also noticed by other studies, the effectiveness of MVRB feature highly relies on the re-compression operation. If the...
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