46 research outputs found
Graph-based person signature for person re-identifications
The task of person re-identification (ReID) is to match images of the same person over multiple non-overlapping camera views. Due to the variations in visual factors, previous works have investigated how the person identity, body parts, and attributes benefit the person ReID problem. However, the correlations between attributes, body parts, and within each attribute are not fully utilized. In this paper, we propose a new method to effectively aggregate detailed person descriptions (attributes labels) and visual features (body parts and global features) into a graph, namely Graph-based Person Signature, and utilize Graph Convolutional Networks to learn the topological structure of the visual signature of a person. The graph is integrated into a multi-branch multi-task framework for person re-identification. The extensive experiments are conducted to demonstrate the effectiveness of our proposed approach on two large-scale datasets, including Market-1501 and DukeMTMC-ReID. Our approach achieves competitive results among the state of the art and outperforms other attribute-based or mask-guided methods. Source available at https://github.com/aioz-ai/CVPRW21_GPS
Energy-efficient precoding in multicell networks with full-duplex base stations
© 2017, The Author(s). This paper considers multi-input multi-output (MIMO) multicell networks, where the base stations (BSs) are full-duplex transceivers, while uplink and downlink users are equipped with multiple antennas and operate in a half-duplex mode. The problem of interest is to design linear precoders for BSs and users to optimize the network’s energy efficiency. Given that the energy efficiency objective is not a ratio of concave and convex functions, the commonly used Dinkelbach-type algorithms are not applicable. We develop a low-complexity path-following algorithm that only invokes one simple convex quadratic program at each iteration, which converges at least to the local optimum. Numerical results demonstrate the performance advantage of our proposed algorithm in terms of energy efficiency
Accumulation of fibronectin in the heart after myocardial infarction: a putative stimulator of adhesion and proliferation of adipose-derived stem cells
Stem cell therapy is a promising treatment after myocardial infarction (MI). A major problem in stem cell therapy, however, is that only a small proportion of stem cells applied to the heart can survive and differentiate into cardiomyocytes. We hypothesized that fibronectin in the heart after MI might positively affect stem cell adhesion and proliferation at the site of injury. Therefore, we investigated the kinetics of attachment and proliferation of adipose-tissue-derived stem cells (ASC) on fibronectin and analysed the time frame and localization of fibronectin accumulation in the human heart after MI. ASCs were seeded onto fibronectin-coated and uncoated culture wells. The numbers of adhering ASC were quantified after various incubation periods (5-30 min) by using DNA quantification assays. The proliferation of ASC was quantified after culturing ASC for various periods (0-9 days) by using DNA assays. Fibronectin accumulation after MI was quantified by immunohistochemical staining of heart sections from 35 patients, after different infarction periods (0-14 days old). We found that ASC attachment and proliferation on fibronectin-coated culture wells was significantly higher than on uncoated wells. Fibronectin deposition was significantly increased from 12 h to 14 days post-infarction, both in the infarction area and in the border-zone, compared with the uninfarcted heart. Our results suggest that a positive effect of fibronectin on stem cells in the heart can only be achieved when stem cell therapy is applied at least 12 h after MI, when the accumulation of fibronectin occurs in the infarcted heart. © 2008 The Author(s)
A large mid-infrared spectroscopic and near-infrared imaging survey of ultraluminous infrared galaxies: Their nature and evolution
A large mid-infrared spectroscopic and near-infrared imaging survey of ultraluminous infrared galaxies: Their nature and evolution
We present a low-resolution mid-infrared spectroscopic survey of an unbiased sample of 62 ultralu-minous infrared galaxies (ULIRGs) z 0.3) using ISOPHOT-S on board the Infrared(L IR [ 1012L _,Space Observatory (ISO). For comparison, we also present ISOPHOT-S spectra for 23 active galactic nuclei (AGNs) and 15 starburst and normal galaxies. The line-to-continuum ratio of the 7.7 km poly-cyclic aromatic hydrocarbon (PAH) emission feature is used as a discriminator between starburst and AGN activity in ULIRGs. We Ðnd that the majority of ULIRGs are predominantly powered by star-bursts. The ratio of PAH over infrared luminosities, for starburst-dominated ULIRGs is veryL PAH/L IR,similar to the ratio found for template starbursts. The shapes of the PAH features are sometimes unusual. Extinction has a noticeable eect on the PAH spectra of ULIRG starbursts. We have obtained high-resolution near-infrared imaging for the southern ISOPHOT-S ULIRGs in order to investigate their evolution stage. The majority (68%) of the ULIRGs imaged are double systems, and all show dis-torted morphologies. Of the 23 double-nuclei systems, 17 appear at linear separations between 4 and 14 kpc, with a mean separation of 6.5 kpc. Using the separations measured from our new near-infrared imaging as well as from the literature, we have examined whether ULIRGs that are advanced mergers are more AGN-like. We have found no such evidence, contrary to what is postulated by the classical evolutionary scenario. No correlation is found between the stage of merger in ULIRGs and their infra
Men who have sex with men in southern Vietnam report high levels of substance use and sexual risk behaviours but underutilise HIV testing services: A cross-sectional study
Objectives This study aims to investigate the levels and correlates of unprotected anal intercourse (UAI), drug and alcohol use, and HIV testing among Vietnamese men who have sex with men (MSM). Methods A total of 381 MSM were recruited in a community-based cross-sectional survey in two towns (Long Xuyen and Chau Doc) in An Giang province in 2009 by using a two-stage cluster sampling. Face-toface interviews were conducted to elicit respondents' characteristics. Regression analysis was used to determine the correlates of key behavioural outcomes. Results In the month before being interviewed, 19.9% respondents had used drugs (13.6% injected), 25.2% had consumed alcohol daily and 33.9% had a UAI with ≥2 male partners. Only 19.2% were tested for HIV in the 12 months before being interviewed. Injecting drug use was significantly associated with having sexual partners who also inject, whereas daily alcohol consumption was associated with an ever-married/ cohabiting with women, being transgender and having had at least three male partners in the previous 3 months. Transactional sex, weekly alcohol use, early sexual debut and perception of being at higher risk of HIV infection were correlates of UAI in multiple partnerships. MSM who self-identified as not being gay and those who perceived themselves to be at low risk of HIV infection were less likely to test for HIV. Conclusions Due to the scarcity of effective MSMtargeted prevention programmes, it is likely that substance use, risky sexual behaviours and low testing uptake may substantially contribute to the spread of HIV among Vietnamese MSM sampled. Harm reduction programmes targeting MSM, and in particular injecting MSM, should be rolled-out in this province
Retained stimulating perineural catheter placed with hydrodissection but without nerve stimulation
Chikungunya and Zika Virus Cases Detected against a Backdrop of Endemic Dengue Transmission in Vietnam
Between 2010 and 2014, four chikungunya and two Zika virus infections were identified among 8,105 febrile children in southern Vietnam. Zika viruses were linked to French Polynesian strains, chikungunya to Cambodian strains. Against a backdrop of endemic dengue transmission, chikungunya and Zika present an additional arboviral disease burden in Vietnam