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71,894 Research products, page 1 of 7,190

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  • Open Access
    Authors: 
    Jimmy A. Irwin; W. Peter Maksym; Gregory R. Sivakoff; Aaron J. Romanowsky; Dacheng Lin; Tyler Speegle; Ian Prado; David T. Mildebrath; Jay Strader; Jifeng Liu; +1 more
    Publisher: Springer Science and Business Media LLC
    Project: NSERC , NSF | Collaborative Research: R... (1515084), NSF | Collaborative Research: R... (1514763), NSF | Black Holes in Globular C... (1308124)

    An X-ray flaring source was found near the galaxy NGC 4697. Two flares were seen, separated by four years. The flux increased by a factor of 90 on a timescale of about one minute. Both flares were very brief. There is no optical counterpart at the position of the flares, but if the source was at the distance of NGC 4697, the luminosities were 10^39 erg/s. Here we report the results of a search of archival X-ray data for 70 nearby galaxies looking for similar such flares. We found two flaring sources in globular clusters or ultra-compact dwarf companions of parent elliptical galaxies. One source flared once to a peak luminosity of 9 x 10^40 erg/s, while the other flared five times to 10^40 erg/s. All of the flare rise times were <1 minute, and they then decayed over about an hour. When not flaring, the sources appear to be normal accreting neutron star or black hole X-ray binaries, but they are located in old stellar populations, unlike the magnetars, anomalous X-ray pulsars or soft gamma repeaters that have repetitive flares of similar luminosities. Published in the Oct 20 2016 issue of Nature

  • Open Access
    Authors: 
    Elaine Ruth Martyn;
    Publisher: University of New Brunswick Libraries - UNB
    Country: Canada
  • Publication . Conference object . Part of book or chapter of book . 2017
    Open Access English
    Authors: 
    Yu Hao; Zhijie Xu; Jing Wang; Ying Liu; Jiulun Fan;
    Publisher: IEEE
    Country: United Kingdom

    With the purpose of automatic detection of crowd patterns including abrupt and abnormal changes, a novel approach for extracting motion “textures” from dynamic Spatio-Temporal Volume (STV) blocks formulated by live video streams has been proposed. This paper starts from introducing the common approach for STV construction and corresponding Spatio-Temporal Texture (STT) extraction techniques. Next the crowd motion information contained within the random STT slices are evaluated based on the information entropy theory to cull the static background and noises occupying most of the STV spaces. A preprocessing step using Gabor filtering for improving the STT sampling efficiency and motion fidelity has been devised and tested. The technique has been applied on benchmarking video databases for proof-of-concept and performance evaluation. Preliminary results have shown encouraging outcomes and promising potentials for its real-world crowd monitoring and control applications.

  • Open Access
    Authors: 
    Suping Cai; Liyu Huang; Jia Zou; Longlong Jing; Buzhong Zhai; Gongjun Ji; Karen M von Deneen; Junchan Ren; Aifeng Ren; Alzheimer’s Disease Neuroimaging Initiative;
    Publisher: Public Library of Science (PLoS)
    Project: NIH | Alzheimers Disease Neuroi... (1U01AG024904-01), CIHR , NIH | "MR Morphometrics and Cog... (5K01AG030514-02), NIH | UC Davis Alzheimer's Core... (3P30AG010129-28S1)

    We used resting-state functional magnetic resonance imaging (fMRI) to investigate changes in the thalamus functional connectivity in early and late stages of amnestic mild cognitive impairment. Data of 25 late stages of amnestic mild cognitive impairment (LMCI) patients, 30 early stages of amnestic mild cognitive impairment (EMCI) patients and 30 well-matched healthy controls (HC) were analyzed from the Alzheimer’s disease Neuroimaging Initiative (ADNI). We focused on the correlation between low frequency fMRI signal fluctuations in the thalamus and those in all other brain regions. Compared to healthy controls, we found functional connectivity between the left/right thalamus and a set of brain areas was decreased in LMCI and/or EMCI including right fusiform gyrus (FG), left and right superior temporal gyrus, left medial frontal gyrus extending into supplementary motor area, right insula, left middle temporal gyrus (MTG) extending into middle occipital gyrus (MOG). We also observed increased functional connectivity between the left/right thalamus and several regions in LMCI and/or EMCI including left FG, right MOG, left and right precuneus, right MTG and left inferior temporal gyrus. In the direct comparison between the LMCI and EMCI groups, we obtained several brain regions showed thalamus-seeded functional connectivity differences such as the precentral gyrus, hippocampus, FG and MTG. Briefly, these brain regions mentioned above were mainly located in the thalamo-related networks including thalamo-hippocampus, thalamo-temporal, thalamo-visual, and thalamo-default mode network. The decreased functional connectivity of the thalamus might suggest reduced functional integrity of thalamo-related networks and increased functional connectivity indicated that aMCI patients could use additional brain resources to compensate for the loss of cognitive function. Our study provided a new sight to understand the two important states of aMCI and revealed resting-state fMRI is an appropriate method for exploring pathophysiological changes in aMCI.

  • Open Access English
    Authors: 
    Guangzhao Chen; Xia Li; Xiaoping Liu; Yimin Chen; Xun Liang; Jiye Leng; Xiaocong Xu; Weilin Liao; Yue’an Qiu; Qianlian Wu; +1 more
    Publisher: Nature Portfolio

    Despite its small land coverage, urban land and its expansion have exhibited profound impacts on global environments. Here, we present the scenario projections of global urban land expansion under the framework of the shared socioeconomic pathways (SSPs). Our projections feature a fine spatial resolution of 1 km to preserve spatial details. The projections reveal that although global urban land continues to expand rapidly before the 2040s, China and many other Asian countries are expected to encounter substantial pressure from urban population decline after the 2050s. Approximately 50–63% of the newly expanded urban land is expected to occur on current croplands. Global crop production will decline by approximately 1–4%, corresponding to the annual food needs for a certain crop of 122–1389 million people. These findings stress the importance of governing urban land development as a key measure to mitigate its negative impacts on food production. Shared socioeconomic pathways (SSPs) is a crucial scenario describing the potential of future socio-economic development. The authors here investigate long-term effects of various government policies suggested by different SSPs on urban land and reveal the impact of future urban expansion on other land and food production.

  • Publication . Article . Other literature type . 2020
    Open Access
    Authors: 
    Niloofar Gharesi; Mohammad Mehdi Arefi; Roozbeh Razavi-Far; Jafar Zarei; Shen Yin;
    Publisher: Elsevier BV
    Country: Canada

    Abstract In recent years advanced signal processing techniques are used increasingly to excavate the nonstationary vibration signals and extract elemental-fault information. However, managing and analyzing a multicomponent signal mixed with background noise using only a single analysis tool is not a simple task and may lead to low diagnostic accuracy and a delayed diagnosis. This paper introduces a novel intelligent neuro-wavelet based system with high diagnostic accuracy based on nonrecursive variational mode decomposition (VMD) and wavelet-based neural network, which mainly consists of three steps (i.e. feature extraction (FE), dimension reduction (DR), and fault classification). Firstly, the vibration signals are segmented and processed by a novel nonrecursive VMD, which can decompose the nonstationary signals into a series of discrete modes adaptively, to extract informative features from vibration signals. Multi-Class generalized discriminant analysis is then used in the second step that aims to reduce the dimension of the feature set and improve the computational burden by selecting meaningful information and removing redundant features. In the next step, the obtained features vector is fed to a state-of-the-art hierarchical multi-resolution classifier, so-called wavelet neural network (WNN), which possesses the advantages of both wavelet transform and artificial neural networks for the decision-making. Additionally, to evaluate the information extraction capability of VMD, the subsequent DR method and the calculation accuracy of WNN, other state-of-the-art techniques are used in this work. In this regard, the superiority of the proposed approach is also confirmed through an experimental comparison with published works in the literature.

  • Authors: 
    Chunyan Feng; Min Zhang; Zhenbin Liu; Arun S. Mujumdar; Yuchuan Wang; Lu Chang;
    Publisher: Informa UK Limited

    The addition of rose pollen to the yam paste for 3D printing could not only meet consumers' needs for nutrition and health, but also provide a new way to achieve personalized customization of healt...

  • Open Access English
    Authors: 
    Xi Wang; Alex S. Baldwin; Robert F. Hess;
    Publisher: The Association for Research in Vision and Ophthalmology

    Purpose Our visual system compares the inputs received from the two eyes to estimate the relative depths of features in the retinal image. We investigated how an imbalance in the strength of the input received from the two eyes affects stereopsis. We also explored the level of agreement between different measurements of sensory eye imbalance. Methods We measured the sensory eye imbalance and stereoacuity of 30 normally sighted participants. We made our measurements using a modified amblyoscope. The sensory eye imbalance was assessed through three methods: the difference between monocular contrast thresholds, the difference in dichoptic masking weight, and the contribution of each eye to a fused binocular percept. We referred them as the "threshold imbalance," "masking imbalance," and "fusion imbalance," respectively. The stereoacuity threshold was measured by having subjects discriminate which of four circles were displaced in depth. All of our tests were performed using stimuli of the same spatial frequency (2.5 cycles/degree). Results We found a relationship between stereoacuity and sensory eye imbalance. However, this was only the case for fusion imbalance measurement (ρ = 0.52; P = 0.003). Neither the threshold imbalance nor the masking imbalance was significantly correlated with stereoacuity. We also found the threshold imbalance was correlated with both the fusion and masking imbalances (r = 0.46, P = 0.011 and r = 0.49, P = 0.005, respectively). However, a nonsignificant correlation was found between the fusion and masking imbalances. Conclusions Our findings suggest that there exist multiple types of sensory eye dominance that can be assessed by different tasks. We find only imbalances in dominance that result in biases to fused percepts are correlated with stereoacuity.

  • Open Access English
    Authors: 
    Kains, N.; Bramich, D. M.; Arellano Ferro, A.; Figuera Jaimes, R.; Jørgensen, U. G.; Giridhar, S.; Penny, M. T.; Alsubai, K. A.; Andersen, J. M.; Bozza, V.; +41 more

    Not Available

  • Closed Access
    Authors: 
    Peter Clarkson; Jordan Ponn; Gordon D. Richardson; Frank Rudzicz; Albert Tsang; Jingjing Wang;
    Publisher: Wiley

    We employ computer-based textual analysis to examine disclosure patterns for a sample of US corporate social responsibility (CSR) reports from the period 2002-2016. Starting from 466 features commonly used in computational linguistics, our results show that the linguistics or disclosure patterns in CSR reports can be used to accurately predict the actual CSR performance type of CSR reporters. Specifically, we find that the two most commonly used disclosure characteristics, number of words and number of sentences, alone can be used to predict reporting firms' CSR performance type with 81% accuracy. The accuracy of prediction increases to 96% when the top 50 linguistics features most relevant to firms' CSR performance are included in the prediction model. In addition, we find that the linguistic features of CSR disclosure identified by our study are incrementally value relevant to investors even after controlling for the actual CSR performance score from the professional CSR rating agencies. This finding suggests that the linguistic features of CSR disclosure can be an important venue for capital market participants in evaluating firms' CSR performance type, especially when professional CSR performance ratings are not available.

Advanced search in
Research products
arrow_drop_down
Searching FieldsTerms
Any field
arrow_drop_down
includes
arrow_drop_down
Include:
The following results are related to Canada. Are you interested to view more results? Visit OpenAIRE - Explore.
71,894 Research products, page 1 of 7,190
  • Open Access
    Authors: 
    Jimmy A. Irwin; W. Peter Maksym; Gregory R. Sivakoff; Aaron J. Romanowsky; Dacheng Lin; Tyler Speegle; Ian Prado; David T. Mildebrath; Jay Strader; Jifeng Liu; +1 more
    Publisher: Springer Science and Business Media LLC
    Project: NSERC , NSF | Collaborative Research: R... (1515084), NSF | Collaborative Research: R... (1514763), NSF | Black Holes in Globular C... (1308124)

    An X-ray flaring source was found near the galaxy NGC 4697. Two flares were seen, separated by four years. The flux increased by a factor of 90 on a timescale of about one minute. Both flares were very brief. There is no optical counterpart at the position of the flares, but if the source was at the distance of NGC 4697, the luminosities were 10^39 erg/s. Here we report the results of a search of archival X-ray data for 70 nearby galaxies looking for similar such flares. We found two flaring sources in globular clusters or ultra-compact dwarf companions of parent elliptical galaxies. One source flared once to a peak luminosity of 9 x 10^40 erg/s, while the other flared five times to 10^40 erg/s. All of the flare rise times were <1 minute, and they then decayed over about an hour. When not flaring, the sources appear to be normal accreting neutron star or black hole X-ray binaries, but they are located in old stellar populations, unlike the magnetars, anomalous X-ray pulsars or soft gamma repeaters that have repetitive flares of similar luminosities. Published in the Oct 20 2016 issue of Nature

  • Open Access
    Authors: 
    Elaine Ruth Martyn;
    Publisher: University of New Brunswick Libraries - UNB
    Country: Canada
  • Publication . Conference object . Part of book or chapter of book . 2017
    Open Access English
    Authors: 
    Yu Hao; Zhijie Xu; Jing Wang; Ying Liu; Jiulun Fan;
    Publisher: IEEE
    Country: United Kingdom

    With the purpose of automatic detection of crowd patterns including abrupt and abnormal changes, a novel approach for extracting motion “textures” from dynamic Spatio-Temporal Volume (STV) blocks formulated by live video streams has been proposed. This paper starts from introducing the common approach for STV construction and corresponding Spatio-Temporal Texture (STT) extraction techniques. Next the crowd motion information contained within the random STT slices are evaluated based on the information entropy theory to cull the static background and noises occupying most of the STV spaces. A preprocessing step using Gabor filtering for improving the STT sampling efficiency and motion fidelity has been devised and tested. The technique has been applied on benchmarking video databases for proof-of-concept and performance evaluation. Preliminary results have shown encouraging outcomes and promising potentials for its real-world crowd monitoring and control applications.

  • Open Access
    Authors: 
    Suping Cai; Liyu Huang; Jia Zou; Longlong Jing; Buzhong Zhai; Gongjun Ji; Karen M von Deneen; Junchan Ren; Aifeng Ren; Alzheimer’s Disease Neuroimaging Initiative;
    Publisher: Public Library of Science (PLoS)
    Project: NIH | Alzheimers Disease Neuroi... (1U01AG024904-01), CIHR , NIH | "MR Morphometrics and Cog... (5K01AG030514-02), NIH | UC Davis Alzheimer's Core... (3P30AG010129-28S1)

    We used resting-state functional magnetic resonance imaging (fMRI) to investigate changes in the thalamus functional connectivity in early and late stages of amnestic mild cognitive impairment. Data of 25 late stages of amnestic mild cognitive impairment (LMCI) patients, 30 early stages of amnestic mild cognitive impairment (EMCI) patients and 30 well-matched healthy controls (HC) were analyzed from the Alzheimer’s disease Neuroimaging Initiative (ADNI). We focused on the correlation between low frequency fMRI signal fluctuations in the thalamus and those in all other brain regions. Compared to healthy controls, we found functional connectivity between the left/right thalamus and a set of brain areas was decreased in LMCI and/or EMCI including right fusiform gyrus (FG), left and right superior temporal gyrus, left medial frontal gyrus extending into supplementary motor area, right insula, left middle temporal gyrus (MTG) extending into middle occipital gyrus (MOG). We also observed increased functional connectivity between the left/right thalamus and several regions in LMCI and/or EMCI including left FG, right MOG, left and right precuneus, right MTG and left inferior temporal gyrus. In the direct comparison between the LMCI and EMCI groups, we obtained several brain regions showed thalamus-seeded functional connectivity differences such as the precentral gyrus, hippocampus, FG and MTG. Briefly, these brain regions mentioned above were mainly located in the thalamo-related networks including thalamo-hippocampus, thalamo-temporal, thalamo-visual, and thalamo-default mode network. The decreased functional connectivity of the thalamus might suggest reduced functional integrity of thalamo-related networks and increased functional connectivity indicated that aMCI patients could use additional brain resources to compensate for the loss of cognitive function. Our study provided a new sight to understand the two important states of aMCI and revealed resting-state fMRI is an appropriate method for exploring pathophysiological changes in aMCI.

  • Open Access English
    Authors: 
    Guangzhao Chen; Xia Li; Xiaoping Liu; Yimin Chen; Xun Liang; Jiye Leng; Xiaocong Xu; Weilin Liao; Yue’an Qiu; Qianlian Wu; +1 more
    Publisher: Nature Portfolio

    Despite its small land coverage, urban land and its expansion have exhibited profound impacts on global environments. Here, we present the scenario projections of global urban land expansion under the framework of the shared socioeconomic pathways (SSPs). Our projections feature a fine spatial resolution of 1 km to preserve spatial details. The projections reveal that although global urban land continues to expand rapidly before the 2040s, China and many other Asian countries are expected to encounter substantial pressure from urban population decline after the 2050s. Approximately 50–63% of the newly expanded urban land is expected to occur on current croplands. Global crop production will decline by approximately 1–4%, corresponding to the annual food needs for a certain crop of 122–1389 million people. These findings stress the importance of governing urban land development as a key measure to mitigate its negative impacts on food production. Shared socioeconomic pathways (SSPs) is a crucial scenario describing the potential of future socio-economic development. The authors here investigate long-term effects of various government policies suggested by different SSPs on urban land and reveal the impact of future urban expansion on other land and food production.

  • Publication . Article . Other literature type . 2020
    Open Access
    Authors: 
    Niloofar Gharesi; Mohammad Mehdi Arefi; Roozbeh Razavi-Far; Jafar Zarei; Shen Yin;
    Publisher: Elsevier BV
    Country: Canada

    Abstract In recent years advanced signal processing techniques are used increasingly to excavate the nonstationary vibration signals and extract elemental-fault information. However, managing and analyzing a multicomponent signal mixed with background noise using only a single analysis tool is not a simple task and may lead to low diagnostic accuracy and a delayed diagnosis. This paper introduces a novel intelligent neuro-wavelet based system with high diagnostic accuracy based on nonrecursive variational mode decomposition (VMD) and wavelet-based neural network, which mainly consists of three steps (i.e. feature extraction (FE), dimension reduction (DR), and fault classification). Firstly, the vibration signals are segmented and processed by a novel nonrecursive VMD, which can decompose the nonstationary signals into a series of discrete modes adaptively, to extract informative features from vibration signals. Multi-Class generalized discriminant analysis is then used in the second step that aims to reduce the dimension of the feature set and improve the computational burden by selecting meaningful information and removing redundant features. In the next step, the obtained features vector is fed to a state-of-the-art hierarchical multi-resolution classifier, so-called wavelet neural network (WNN), which possesses the advantages of both wavelet transform and artificial neural networks for the decision-making. Additionally, to evaluate the information extraction capability of VMD, the subsequent DR method and the calculation accuracy of WNN, other state-of-the-art techniques are used in this work. In this regard, the superiority of the proposed approach is also confirmed through an experimental comparison with published works in the literature.

  • Authors: 
    Chunyan Feng; Min Zhang; Zhenbin Liu; Arun S. Mujumdar; Yuchuan Wang; Lu Chang;
    Publisher: Informa UK Limited

    The addition of rose pollen to the yam paste for 3D printing could not only meet consumers' needs for nutrition and health, but also provide a new way to achieve personalized customization of healt...

  • Open Access English
    Authors: 
    Xi Wang; Alex S. Baldwin; Robert F. Hess;
    Publisher: The Association for Research in Vision and Ophthalmology

    Purpose Our visual system compares the inputs received from the two eyes to estimate the relative depths of features in the retinal image. We investigated how an imbalance in the strength of the input received from the two eyes affects stereopsis. We also explored the level of agreement between different measurements of sensory eye imbalance. Methods We measured the sensory eye imbalance and stereoacuity of 30 normally sighted participants. We made our measurements using a modified amblyoscope. The sensory eye imbalance was assessed through three methods: the difference between monocular contrast thresholds, the difference in dichoptic masking weight, and the contribution of each eye to a fused binocular percept. We referred them as the "threshold imbalance," "masking imbalance," and "fusion imbalance," respectively. The stereoacuity threshold was measured by having subjects discriminate which of four circles were displaced in depth. All of our tests were performed using stimuli of the same spatial frequency (2.5 cycles/degree). Results We found a relationship between stereoacuity and sensory eye imbalance. However, this was only the case for fusion imbalance measurement (ρ = 0.52; P = 0.003). Neither the threshold imbalance nor the masking imbalance was significantly correlated with stereoacuity. We also found the threshold imbalance was correlated with both the fusion and masking imbalances (r = 0.46, P = 0.011 and r = 0.49, P = 0.005, respectively). However, a nonsignificant correlation was found between the fusion and masking imbalances. Conclusions Our findings suggest that there exist multiple types of sensory eye dominance that can be assessed by different tasks. We find only imbalances in dominance that result in biases to fused percepts are correlated with stereoacuity.

  • Open Access English
    Authors: 
    Kains, N.; Bramich, D. M.; Arellano Ferro, A.; Figuera Jaimes, R.; Jørgensen, U. G.; Giridhar, S.; Penny, M. T.; Alsubai, K. A.; Andersen, J. M.; Bozza, V.; +41 more

    Not Available

  • Closed Access
    Authors: 
    Peter Clarkson; Jordan Ponn; Gordon D. Richardson; Frank Rudzicz; Albert Tsang; Jingjing Wang;
    Publisher: Wiley

    We employ computer-based textual analysis to examine disclosure patterns for a sample of US corporate social responsibility (CSR) reports from the period 2002-2016. Starting from 466 features commonly used in computational linguistics, our results show that the linguistics or disclosure patterns in CSR reports can be used to accurately predict the actual CSR performance type of CSR reporters. Specifically, we find that the two most commonly used disclosure characteristics, number of words and number of sentences, alone can be used to predict reporting firms' CSR performance type with 81% accuracy. The accuracy of prediction increases to 96% when the top 50 linguistics features most relevant to firms' CSR performance are included in the prediction model. In addition, we find that the linguistic features of CSR disclosure identified by our study are incrementally value relevant to investors even after controlling for the actual CSR performance score from the professional CSR rating agencies. This finding suggests that the linguistic features of CSR disclosure can be an important venue for capital market participants in evaluating firms' CSR performance type, especially when professional CSR performance ratings are not available.