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.
Transfer learning aims to extract the knowledge from a label-rich source domain to enhance the predictive model of a target domain. Previous methods achieve knowledge transfer by detecting a shared low-dimensional feature representation from source domain to target domain. Along this line, many algorithms, e.g., dual transfer learning (DTL), triplex transfer learning (TRi-TL) etc., have been proposed...
During real-world experiences, determining the stimulus-relevant brain activity is excitingly attractive and is very challenging, particularly in electroencephalography. Here, spectrograms of ongoing electroencephalogram (EEG) of one participant constructed a third-order tensor with three factors of time, frequency and space; and the stimulus data consisting of acoustical features derived from the...
Web pages often contain “clutters” (defined by us as unnecessary images, navigational menus and extraneous Ad links) around the body of an article that may distract users from the actual content. Therefore, how to extract useful and relevant themes from these web pages becomes a research focus. This paper proposes a new method for web theme extraction. The method firstly uses page segmentation technique...
In this paper, we present a No-Word-Segmentation Hierarchical Clustering Approach (NWSHCA) to Chinese Web search results. The approach uses a new similarity measure between two documents based on a variation of the Edit Distance, and then it generates preliminary clusters using a partitioning clustering method. Next it ranks all common substring in a cluster using a cluster-discriminative metric with...
Long-range underwater acoustic communication (UWAC) faces many difficulties such as great propagation loss, high ambient noise and long multipath delay. In order to design an excellent long-range UWAC system, it is necessary to increase signal-to-noise ratio (SNR), suppress inter-symbol interface (ISI) and alleviate frequency selective fading. In this paper, a novel time frequency shift keying scheme...
Feature selection plays an important role in machinelearning applications. Especially for text data, the highdimensionaland sparse characteristics will affect the performanceof feature selction. In this paper, an unsupervised feature selection algorithm through Random Projection and Gram-Schmidt Orthogonalization (RP-GSO) from the word co-occurrence matrix is proposed. The RP-GSO has three advantages:...
Aspect-based opinion mining is to find elaborate opinions towards an underlying theme, perspective or viewpoint as to a subject such as a product or an event. Nowadays, with rapid growing of opinionated text on theWeb, mining aspect-level opinions has become a promising means for online public opinion analysis. In particular, the booming of various types of online media provide diverse yet complementary...
An iterative block decision-feedback equalizer based on LDPC (LDPC-IBDEF) for SCFDE underwater acoustic (UWA) communication system is proposed. The new equalizer employs IBDFE together with iterative LDPC decoding technique, leading to a double-layer structure which can solve the frequency selective fading problem in UWA channel. In the outer-layer, IBDFE iteratively exchanges information with the...
In the task of cross-language sentiment classification, the monolingual machine learning based approaches suffer from the shortage of available sentiment resources in target language. In order to reduce the cost of labeling the documents from a new language, many proposed approaches transfer the sentiment knowledge from resource-rich languages (e.g. English) to resource-poor languages (e.g. Chinese)...
Topic model has attracted much attention from investigators, as it provides users with insights into the huge volumes of documents. However, most previous related studies that based on Non-negative Matrix Factorization (NMF) neglect to figure out which topics are widespread in the documents and which are not. These widespread topics, which we refer to coarse-grained topics, have great significance...
An underwater multiuser cooperative communication system based on minimum mean-square error decision feedback detection (MMSE-DFD) algorithm is proposed, where communication between two source nodes and one destination node is assumed. In this paper, underwater acoustic (UWA) channel is modeled as a sparse multipath channel experiencing Rayleigh fading. Compared with the traditional multiuser cooperative...
Considering the scattering and absorption caused by seawater molecules and suspended particles, the characteristics of blue-green laser in seawater are described. Then a transmission model of blue-green laser in shallow seawater is established and the relations of the attenuation of received power and the requisite transmission power to the transmission distance are summed up. Results of the simulation...
Recently topic model has been more and more popular in lots of fields such as information retrieval and semantic relatedness computing, but its practical application is limited to the scalability of data. It cannot be efficiently executed on large-scale datasets in a parallel way. In this paper, we introduce an improved Regularized Latent Semantic Indexing(RLSI) with L1/2 regularization and non-negative...
In this paper, we investigate the performance of carrier sensing multiple access (CSMA)-based medium access control (MAC) protocol in fully connected underwater acoustic sensor networks (UWASNs). CSMA-based MAC protocols run inefficiently because of a new hidden terminal problem (we refer to it as “long-delay hidden terminal problem”). Based on our findings, this paper presents novel performance analysis...
An Underwater acoustic channel is characterized as time-varying, multipath environment. In order to get a better location result, we firstly analysised the environment in the water tank and modeled it in this paper. Using long time observation, the successive time-variant impulse response and the statistical parameters changing is obtained. All these parameters can effectively avoid multipath (indirect)...
With the increase of applications on underwater wireless sensor networks (UWSN), reliability of underwater communication (UWC) has become increasingly demanding. In this paper, a new underwater acoustic modem prototype design based M-ary different chirp spread signals (MCSS) is presented. Through sea test, it is verified that under low SNR shallow water environment, the modem can achieve error-free...
Wavelet packet transform is an efficient method in speech denoising processing. In this paper, we research on various wavelet packet basis, decomposition layers, values of the threshold and threshold functions which are key parameters in wavelet packet denoising. Furthermore, we adopt three methods to evaluate the effects of denoised speech, including signal-noise-ratio(SNR), wavelet spectrum distortion...
Open source projects often maintain open bug repositories during development and maintenance, and the reporters often point out straightly or implicitly the reasons why bugs occur when they submit them. The comments about a bug are very valuable for developers to locate and fix the bug. Meanwhile, it is very common in large software for programmers to override or overload some methods according to...
In this paper, an improved adaptive update and adaptive prediction algorithm is put forward. The method makes full use of the correlation of neighboring pixels, which the approximation band and the detail bands obtained by a polyphase decomposition of an original image perform the proposed adaptive update step one by one, then the detail bands perform the adaptive prediction algorithm. The advantage...
It is tough to achieve higher transmit speed and lower bit error rate(BER) because of the complexity of the underwater acoustic channel. This paper proposes a method of orthogonal frequency division multiplexing (OFDM) modulation technique for improving the situation. It can reduce BER with the ability of resisting multi-path interference and can increase communication rate with the characteristic...
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.