158 research outputs found
Research on application of patch near-field acoustic holography using acoustic radiation modes with double layers
To solve the problems of near-field acoustic holography in actual applications, research based on acoustic radiation modes with double layers is studied in this paper. The sound pressure model by using acoustic radiation modes is selected to express the sound field firstly. Then, the sound field separation with double pressure measurement layers has been applied to remove the interference from the opposite direction. Thirdly, the method based on data interpolation and extrapolation is put forward to increase the holographic value equivalently, the results of which are closer to the actual measured value obtained by more measuring points. Numerical simulations based on the theoretical description are conducted to demonstrate the validity of the proposed method, and experiments for a boundary constraint steel plate and a loudspeaker are performed to demonstrate its feasibility
Not only Online Review but also its Helpfulness is Manipulated: Evidence from Peer to Peer Lending Forum
Online reviews have become proposed as useful information for consumers to make decision. Meanwhile, review manipulation will weaken the credibility of online reviews. Except manipulating the review text and rating, we propose that review helpfulness, an important signal for consumer to filter the reviews, could also be manipulated. This study thus explores the existence of review helpfulness manipulation and the relationship between firm quality and review manipulation. Based on a dataset from a review forum in www.wdzj.com which is the leading and largest portal of peer to peer lending industry in China, we get the following interesting results. First, due to the manipulation of review helpfulness, a manipulated positive review is more likely to receive higher helpfulness, while a manipulated negative is more likely to get lower helpfulness. Second, a manipulated review tends to be lower quality in terms of readability and word count, which are found as positive predictors for review helpfulness. Third, high quality firms tend to manipulate more positive reviews, and at the same time high quality firms will receive more negative manipulated reviews. This study extends current understanding about online review manipulation, thereby providing theoretical and practice implications
Transforming Wikipedia into Augmented Data for Query-Focused Summarization
The manual construction of a query-focused summarization corpus is costly and
timeconsuming. The limited size of existing datasets renders training
data-driven summarization models challenging. In this paper, we use Wikipedia
to automatically collect a large query-focused summarization dataset (named as
WIKIREF) of more than 280,000 examples, which can serve as a means of data
augmentation. Moreover, we develop a query-focused summarization model based on
BERT to extract summaries from the documents. Experimental results on three DUC
benchmarks show that the model pre-trained on WIKIREF has already achieved
reasonable performance. After fine-tuning on the specific datasets, the model
with data augmentation outperforms the state of the art on the benchmarks
Sound field separation technique using the principle of double layer patch acoustic radiation modes
In order to solve the problems of near-field acoustic holography in applications such as external interference and aperture effects, a sound field separation technique using the principle of double layer patch acoustic radiation modes is proposed in this paper. The radiated acoustic pressures over two planar surfaces at certain distances from the sources are calculated first. Then, the effects resulting from the backscattering interference in non-free sound fields can be eliminated by a double-layer sound field separation technique. Next, data interpolation and extrapolation are performed on the separated data to increase the sound source's pressures on the holographic plane equivalently for holographic images with higher spatial resolution. Simulation and experimental results demonstrate that good agreements can be obtained with few measuring points
Sound field separation technique using the principle of double layer patch acoustic radiation modes
In order to solve the problems of near-field acoustic holography in applications such as external interference and aperture effects, a sound field separation technique using the principle of double layer patch acoustic radiation modes is proposed in this paper. The radiated acoustic pressures over two planar surfaces at certain distances from the sources are calculated first. Then, the effects resulting from the backscattering interference in non-free sound fields can be eliminated by a double-layer sound field separation technique. Next, data interpolation and extrapolation are performed on the separated data to increase the sound source's pressures on the holographic plane equivalently for holographic images with higher spatial resolution. Simulation and experimental results demonstrate that good agreements can be obtained with few measuring points
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