| 1. |
- Kristan, Matej, et al.
(författare)
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The first visual object tracking segmentation VOTS2023 challenge results
- 2023
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Ingår i: 2023 IEEE/CVF International conference on computer vision workshops (ICCVW). - : Institute of Electrical and Electronics Engineers Inc.. - 9798350307443 - 9798350307450 ; , s. 1788-1810
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Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking Segmentation VOTS2023 challenge is the eleventh annual tracker benchmarking activity of the VOT initiative. This challenge is the first to merge short-term and long-term as well as single-target and multiple-target tracking with segmentation masks as the only target location specification. A new dataset was created; the ground truth has been withheld to prevent overfitting. New performance measures and evaluation protocols have been created along with a new toolkit and an evaluation server. Results of the presented 47 trackers indicate that modern tracking frameworks are well-suited to deal with convergence of short-term and long-term tracking and that multiple and single target tracking can be considered a single problem. A leaderboard, with participating trackers details, the source code, the datasets, and the evaluation kit are publicly available at the challenge website1
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| 2. |
- Kristan, Matej, et al.
(författare)
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The Ninth Visual Object Tracking VOT2021 Challenge Results
- 2021
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Ingår i: 2021 IEEE/CVF INTERNATIONAL CONFERENCE ON COMPUTER VISION WORKSHOPS (ICCVW 2021). - : IEEE COMPUTER SOC. - 9781665401913 ; , s. 2711-2738
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Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking challenge VOT2021 is the ninth annual tracker benchmarking activity organized by the VOT initiative. Results of 71 trackers are presented; many are state-of-the-art trackers published at major computer vision conferences or in journals in recent years. The VOT2021 challenge was composed of four sub-challenges focusing on different tracking domains: (i) VOT-ST2021 challenge focused on short-term tracking in RGB, (ii) VOT-RT2021 challenge focused on "real-time" short-term tracking in RGB, (iii) VOT-LT2021 focused on long-term tracking, namely coping with target disappearance and reappearance and (iv) VOT-RGBD2021 challenge focused on long-term tracking in RGB and depth imagery. The VOT-ST2021 dataset was refreshed, while VOT-RGBD2021 introduces a training dataset and sequestered dataset for winner identification. The source code for most of the trackers, the datasets, the evaluation kit and the results along with the source code for most trackers are publicly available at the challenge website(1).
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| 3. |
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| 4. |
- Li, Hongxia, et al.
(författare)
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A review of deep learning methods for pixel-level crack detection
- 2022
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Ingår i: Journal of Traffic and Transportation Engineering (English Edition). - : KEAI PUBLISHING LTD. - 2095-7564. ; 9:6, s. 945-968
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Forskningsöversikt (refereegranskat)abstract
- Cracks are a major sign of aging transportation infrastructure. The detection and repair of cracks is the key to ensuring the overall safety of the transportation infrastructure. In recent years, due to the remarkable success of deep learning (DL) in the field of crack detection, many researches have been devoted to developing pixel-level crack image seg-mentation (CIS) models based on DL to improve crack detection accuracy, but as far as we know there is no review of DL-based CIS methods yet. To address this gap, we present a comprehensive thematic survey of DL-based CIS techniques. Our review offers several contributions to the CIS area. First, more than 40 papers of journal or top conference most published in the last three years are identified and collected based on the systematic literature review method. Second, according to the backbone network architecture of the models proposed in them, they are grouped into 10 topics: FCN, U-Net, encoder-decoder model, multi-scale, attention mechanism, transformer, two-stage detection, multi-modal fusion, unsupervised learning and weakly supervised learning, to be reviewed. Meanwhile, our survey focuses on discussing strengths and limitations of the models in each topic so as to reveal the latest research progress in the CIS field. Third, publicly accessible data sets, evaluation metrics, and loss functions that can be used for pixel-level crack detection are systematically introduced and summarized to facilitate researchers to select suitable components according to their own research tasks. Finally, we discuss six common problems and existing solutions to them in the field of DL-based CIS, and then suggest eight possible future research directions in this field. (c) 2022 Periodical Offices of Changan University. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC -ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
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| 5. |
- Wang, Limin, et al.
(författare)
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Numerical study on dynamic performance of low temperature recuperator in a S-CO2 Brayton cycle
- 2023
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Ingår i: Numerical Heat Transfer; Part A: Applications. - : Informa UK Limited. - 1040-7782 .- 1521-0634. ; 84:12, s. 1436-1458
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Tidskriftsartikel (refereegranskat)abstract
- Transient response of the pinch point is crucial to the evaluations of the recuperator efficiency. A reheat and recompression cycle dynamic simulation system for supercritical CO2 is built, and a transient segmented model is developed to explore the dynamic characteristics of the recuperators. The operating conditions including inlet mass flowrate, temperature and pressure of the low temperature recuperator (LTR) change dramatically with the withdraw-mass variation, which causes different response characteristics of the pinch point. The pinch point gradually transfers from the cold end to the hot end of the LTR as the mass flowrate decreases. The higher pinch-point temperature difference leads to lower heat exchanger effectiveness, and the internal pinch point greatly weakens the recuperator performance. A new prediction model is proposed to quickly determine the pinch point location and analyze the operating conditions prone to cause internal pinch point. The range of split ratio in which the internal pinch point exists in the LTR is obtained. The lower-limit of split ratio variation is sensitive to the high- and low-pressures, the isentropic efficiency of the compressor, and the outlet temperature of the precooler, while the upper-limit of split ratio is only related to the pressures of the recuperator.
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| 6. |
- Xu, Tao, et al.
(författare)
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Epidemiology of Unintentional Injuries Among Children Under Six Years Old in Floating and Residential Population in Four Communities in Beijing : A Comparative Study
- 2014
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Ingår i: Maternal and Child Health Journal. - : Springer Science and Business Media LLC. - 1092-7875 .- 1573-6628. ; 18:4, s. 911-919
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Tidskriftsartikel (refereegranskat)abstract
- To explore and compare the epidemiological characteristics of non-fatal unintentional injury among children in floating and residential population. Using a structured survey, quantitative data were collected on a total of 352 floating and 201 residential families. Some potential influencing factors were questioned, such as socio-demographic characteristics, injury-related family environment, knowledge, attitude and behavior, and child's character. The self-reported incidence of non-fatal unintentional injuries was 11.9 % in the floating group and 12.9 % in the residential group. Unintentional injuries were more serious and caused more disease burden in floating children than residential children, with the average medical cost being over ten times in the floating group than in the residential group. Results of multiple regression analysis showed that children living in floating families have more risk of unintentional injuries than those children in residential families. Older children and children with extroverted character were more vulnerable to unintentional injuries. Risky family environment was also an important risk factor of unintentional injuries. Better household economic status and having more siblings appeared to reduce the probability of unintentional injuries among children. Floating children are more vulnerable to unintentional injuries comparing with residential children. These findings can be used as preliminary data supporting intervention strategies and activities to promote safe living environment and decrease injury incidence among floating children.
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| 7. |
- Cai, Xiao, et al.
(författare)
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Structure and propagation of spherical turbulent iron-methane hybrid flame at elevated pressure
- 2023
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Ingår i: Combustion and Flame. - 0010-2180. ; 255
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Tidskriftsartikel (refereegranskat)abstract
- In this communication we demonstrate the role of turbulence intensity in the dual-front structure and self-similar propagation of spherical turbulent iron-methane hybrid flames. We first show that iron-methane hybrid mixture, whose iron concentration is below a critical threshold for the formation of a dust flame front in laminar or weak turbulent environment, can be burned strongly with both separated dual-front and merged single-front structures in intense turbulence. It is suggested that the formation of iron flame front would be attributed to local iron concentration accumulation by preferential sampling with near-unity Stocks number (St), heat transfer enhancement of iron particles to fluid and mixing promotion of iron particles with oxidants by strong turbulence. The propagation of iron front falls behind the methane front in the leading segments which is promoted by flame stretch for sub-unity Lewis number (Le), thus the separated dual-front structure occurs. Furthermore, the strong self-similar propagation of spherical turbulent iron-methane hybrid flame was observed under different turbulence intensities (urms). Mechanistically, such strong self-similar propagation of the hybrid flame is the consequence of the couple effects of flame mode transition at high urms with near-unity St and differential diffusion for sub-unity Le.
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| 8. |
- Gu, Limin, et al.
(författare)
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Case Studies on the Use of Technology in TPD (Teacher Professional Development)
- 2012
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Ingår i: US-China Education Review. A. - : David Publishing Company. - 2161-623X .- 1548-6613 .- 1930-1529. ; 2:3, s. 278-290
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the progress of a three-year cooperative project investigating the current state of TPD (teacher professional development) in Sweden and China in the area of TPD and ICT (information and communication technologies) is summarized. A brief introduction to the field of TPD is given, and thereafter, ICT is related to what in the project is referred to as TETPD (Technology Enhanced Teacher Professional Development). Thereafter, the project as such is given a short presentation, followed by findings regarding policies and initiatives related to TETPD in Sweden and China for investigating the current state of TETPD in each country respectively. The framework for investigating TETPD is presented, and four Chinese and four Swedish cases are compared to some facets showing differences in models for TETPD in the two countries.
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| 9. |
- Li, Qiang, et al.
(författare)
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Experimental Demonstration of Plasmon Propagation, Coupling, and Splitting in Silver Nanowire at 1550-nm Wavelength
- 2011
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Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - 1077-260X .- 1558-4542. ; 17:4, s. 1107-1111
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally demonstrate silver-nanowire-based plasmonic devices including the nanowaveguide, the nanocoupler, and the nanosplitter at optical communication wavelength of 1550 nm. The plasmon propagation loss in a 300-nm diameter silver nanowire is measured to be 0.3 dB/mu m and the effective propagation length is 14.5 mu m. This loss is comparatively lower than that at 980 nm. Two types of plasmonic functional devices based on the coupling between two silver nanowires, nanocouplers, and nanosplitters, are realized. For the nanocoupler, the experimental results show that the plasmonic modes can be efficiently coupled between two closely positioned nanowires. While for the nanosplitter, the plasmonic mode is split with a power ratio of 2.6:1. These demonstrations experimentally prove the feasibility of extending the operating wavelength of silver-nanowire-based plasmonic devices to current optical communication wavelength with a lower loss, which are thus important steps for potentially utilizing low-loss nanowire-based plasmonic components for photonic integrated circuits.
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| 10. |
- Li, Qiang, et al.
(författare)
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Experimental demonstration of plasmon propagation, coupling, and splitting in silver nanowire at 1550-nm wavelength
- 2011
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Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - : IEEE. - 1077-260X .- 1558-4542. ; 17:4, s. 1107-1111
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally demonstrate silver-nanowire-based plasmonic devices including the nanowaveguide, the nanocoupler, and the nanosplitter at optical communication wavelength of 1550 nm. The plasmon propagation loss in a 300-nm diameter silver nanowire is measured to be 0.3 dB/μm and the effective propagation length is 14.5 μm. This loss is comparatively lower than that at 980 nm. Two types of plasmonic functional devices based on the coupling between two silver nanowires, nanocouplers, and nanosplitters, are realized. For the nanocoupler, the experimental results show that the plasmonic modes can be efficiently coupled between two closely positioned nanowires. While for the nanosplitter, the plasmonic mode is split with a power ratio of 2.6:1. These demonstrations experimentally prove the feasibility of extending the operating wavelength of silver-nanowire-based plasmonic devices to current optical communication wavelength with a lower loss, which are thus important steps for potentially utilizing low-loss nanowire-based plasmonic components for photonic integrated circuits.
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