274 research outputs found

    Multi-theme sentiment analysis with sentiment shifting

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    Business reviews contain rich sentiment on multiple themes, disclosing more interesting information than the overall polarities of documents. When it comes to fine-grained sentiment analysis, given any segment of text, we are not only interested in overall polarity of such segment, but also the sentiment words play major effects. However, sentiment analysis at the word level poses significant challenges due to the complexity of reviews, the inconsistency of sentiment in different themes, and the sentiment shifting resulting from linguistic patterns---contextual valence shifters. To simultaneously resolve the multi-theme and sentiment shifting dilemma, a unified explainable sentiment analysis model, MTSA, is proposed in this paper, which enables both classification of sentiment polarity and discovery of quantified sentiment-shifting patterns. MTSA formulates multi-theme sentiment by learning embeddings (i.e., vector representations) for both themes and words, and derives the shifter effect learning algorithm by modeling the shifted sentiment in a logistic regression model. Extensive experiments have been conducted on Yelp business reviews and IMDB movie reviews. The improvement of sentiment polarity classification demonstrates the effectiveness of MTSA at rectifying word feature representations of reviews, and the human evaluation shows its successful discovery of multi-theme sentiment words and automatic effect quantification of contextual valence shifters.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2018-05-01The student, Hongkun Yu, accepted the attached license on 2016-04-20 at 13:24.The student, Hongkun Yu, submitted this Thesis for approval on 2016-04-20 at 13:27.This Thesis was approved for publication on 2016-04-21 at 08:52.DSpace SAF Submission Ingestion Package generated from Vireo submission #9349 on 2016-07-07 at 13:50:14Made available in DSpace on 2016-07-07T20:27:48Z (GMT). No. of bitstreams: 2 YU-THESIS-2016.pdf: 1377626 bytes, checksum: fe33b7692b15580351e718e199b44e59 (MD5) LICENSE.txt: 4207 bytes, checksum: 6ecb6be099535d4749440bbf2fcd7721 (MD5) Previous issue date: 2016-04-21Embargo set by: Seth Robbins for item 93151 Lift date: 2018-07-07T20:28:14Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 93151 Lift date: 2018-07-07T20:35:34Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Only Restriction Lifted for Item 93151 on 2018-07-08T09:15:16Z

    Morphology Modelling for On-line Wear Debris Monitoring

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    On-line Wear Debris Analysis (WDA) with its rapid fault detection capability in a non-destructive manner, has been increasingly employed in machine condition monitoring. However, the available debris features obtained from current on-line WDA processes are mostly restricted to statistical indicators due to the limited data quality. Morphological features extraction from individual debris, hence, has not been fully successful in practice. Moreover, wear debris detections are currently relying on single-side or two-dimensional (2-D) debris features, while the three-dimensional (3-D) features that contain valuable morphological information are still not accessible in on-line WDA and its further application is thus impeded. To extract more individual debris features in current on-line WDA, this research aims at formulating an efficient scheme with improved debris observation, robust features extraction and 3-D debris shape measurement. First, an automatic framework is established to collect debris information in multi-views by observing the moving debris in a flow cell. Since the debris profiles are captured when it is moving, motion blur inevitably occurs and degrades the image quality. A fusion based restoration method is then developed to remove the motion blur by integrating multiple deblurring processes over several localised Point Spread Function (PSF). Furthermore, out-of-focus blur often occurs as another predominant source of degradation that leads to low feature extraction accuracy. This problem is tackled here by utilising a Convolutional Neural Networks (CNN) to model the defocus process and then remove the degradation. Finally, given the improved debris profiles, a debris shape measurement procedure is constructed to estimate 3-D debris features by minimising the discrepancies between multiple potential reconstructions. Through validation experiments and comparisons, it indicates that the proposed 3-D measurement framework could enable the observed debris information to be extended into the third dimension that is rarely achieved by available on-line detectors for WDA. Compared with other debris imaging approaches, the developed method allows the estimation of material loss based on the measured debris volume. Furthermore, the classification of debris shape into chunk, laminar and sphere is now accomplishable with no specialised equipment. The industrial practicability of WDA can be improved considerably

    A novel top-down fabrication process for Ge2Sb2Te5 phase change material nanowires

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    A novel e-beam free, top-down spacer etch process was used to fabricate sub-hundred nanometer Ge2Sb2Te5 phase change nanowires. Naowires with a cross-section dimension of 50 nm × 100 nm (width × height) were obtained and phase change functionality demonstrated
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