| 1. |
- Kristan, Matej, et al.
(författare)
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The Visual Object Tracking VOT2017 challenge results
- 2017
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Ingår i: 2017 IEEE INTERNATIONAL CONFERENCE ON COMPUTER VISION WORKSHOPS (ICCVW 2017). - : IEEE. - 9781538610343 ; , s. 1949-1972
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Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking challenge VOT2017 is the fifth annual tracker benchmarking activity organized by the VOT initiative. Results of 51 trackers are presented; many are state-of-the-art published at major computer vision conferences or journals in recent years. The evaluation included the standard VOT and other popular methodologies and a new "real-time" experiment simulating a situation where a tracker processes images as if provided by a continuously running sensor. Performance of the tested trackers typically by far exceeds standard baselines. The source code for most of the trackers is publicly available from the VOT page. The VOT2017 goes beyond its predecessors by (i) improving the VOT public dataset and introducing a separate VOT2017 sequestered dataset, (ii) introducing a realtime tracking experiment and (iii) releasing a redesigned toolkit that supports complex experiments. The dataset, the evaluation kit and the results are publicly available at the challenge website(1).
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| 2. |
- Zhong, Yi, et al.
(författare)
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Role of land-ocean interactions in stepwise Northern Hemisphere Glaciation
- 2024
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Ingår i: Nature Communications. - 2041-1723. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- The investigation of triggers causing the onset and intensification of Northern Hemisphere Glaciation (NHG) during the late Pliocene is essential for understanding the global climate system, with important implications for projecting future climate changes. Despite their critical roles in the global climate system, influences of land-ocean interactions on high-latitude ice sheets remain largely unexplored. Here, we present a high-resolution Asian dust record from Ocean Drilling Program Site 1208 in the North Pacific, which lies along the main route of the westerlies. Our data indicate that atmosphere-land-ocean interactions affected aeolian dust emissions through modulating moisture and vegetation in dust source regions, highlighting a critical role of terrestrial systems in initiating the NHG as early as 3.6 Myr ago. Combined with additional multi-proxy and model results, we further show that westerly wind strength was enhanced, mainly at low-to-middle tropospheric levels, during major glacial events at about 3.3 and 2.7 Myr ago. We suggest that coupled responses of Earth’s surface dynamics and atmospheric circulation in the Plio-Pleistocene likely involved feedbacks related to changes in paleogeography, ocean circulation, and global climate.
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| 3. |
- Chen, Yu, 1990, et al.
(författare)
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Single-cell omics analysis with genome-scale metabolic modeling
- 2024
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Ingår i: Current Opinion in Biotechnology. - 0958-1669 .- 1879-0429. ; 86
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Forskningsöversikt (refereegranskat)abstract
- Single-cell technologies have been widely used in biological studies and generated a plethora of single-cell data to be interpreted. Due to the inclusion of the priori metabolic network knowledge as well as gene–protein–reaction associations, genome-scale metabolic models (GEMs) have been a powerful tool to integrate and thereby interpret various omics data mostly from bulk samples. Here, we first review two common ways to leverage bulk omics data with GEMs and then discuss advances on integrative analysis of single-cell omics data with GEMs. We end by presenting our views on current challenges and perspectives in this field.
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| 4. |
- Feng, Yifan, et al.
(författare)
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Fractal Superconducting Nanowire Single-Photon Detectors and Their Applications in Imaging
- 2022
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Ingår i: Proceedings of the 2022 Conference on Lasers and Electro-Optics Pacific Rim, CLEO/PR 2022. - : Optica Publishing Group.
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Konferensbidrag (refereegranskat)abstract
- We present our research on fractal superconducting nanowire single-photon detectors and their applications in light detection and ranging (LiDAR), full-Stokes polarimetric imaging, and non-line-of-sight imaging.
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| 5. |
- Feng, Yifan, et al.
(författare)
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Fractal Superconducting Nanowire Single-Photon Detectors and Their Applications in Imaging
- 2022
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Ingår i: 2022 Conference on Lasers and Electro-Optics Pacific Rim, CLEO-PR 2022 - Proceedings. - : Institute of Electrical and Electronics Engineers Inc..
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Konferensbidrag (refereegranskat)abstract
- We present our research on fractal superconducting nanowire single-photon detectors and their applications in light detection and ranging (LiDAR), full-Stokes polarimetric imaging, and non-line-of-sight imaging.
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| 6. |
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| 7. |
- Hu, Jingyu, et al.
(författare)
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Integrated multi-material and multi-scale optimization of compliant structure with embedded movable piezoelectric actuators
- 2024
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Ingår i: Computer Methods in Applied Mechanics and Engineering. - 0045-7825. ; 421
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Tidskriftsartikel (refereegranskat)abstract
- Piezoelectric actuators embedded in compliant structures have many potential applications, which call for effective design approaches. Existing optimization driven design methods focus on the piezoelectric actuator location or the macro topology of the host compliant structure while ignoring the possibility to exploit the use of multiple materials and hierarchical material design. In this study, an integrated, density-based multi-material and multi-scale optimization method for compliant structures with embedded movable piezoelectric actuators is proposed. The design variables in the optimization represent the location of the piezoelectric actuators and the layout of the macro/micro host structures. To mitigate the risk of suboptimal designs, the three sets of design variables are simultaneously optimized using gradient-based optimization where the gradients are computed using the adjoint method. A material interpolation model that describes the piezoelectric actuators, multiple lattice materials of the host structure as well as their coating layer is proposed. To illustrate the formulation, several compliant structures embedded with movable piezoelectric actuators are designed such that the displacement at an output port is maximized. Macro and micro volume fractions, and overlapping of piezoelectric actuators are constrained in the optimization.
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| 8. |
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| 9. |
- Wang, Jingyu, et al.
(författare)
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A network model and numerical simulations of flow distributions in packed bed reactors with different packing structures
- 2020
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Ingår i: Applied Thermal Engineering. - : Elsevier BV. - 1359-4311. ; 172
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Tidskriftsartikel (refereegranskat)abstract
- Due to the high specific surface area, packed bed reactors are widely used in real engineering applications. The flow distribution, which is highly dependent on the packing structure, can be vital for the heat/mass transfer and reaction performances. This makes the study of the flow distribution in packed beds quite important. In the present paper, an equivalent network model based on the Voronoi tessellation is proposed to predict the flow field. In addition, a relationship between the hydraulic resistance and the pore structure is introduced. Besides, the influence of the packing structure on the flow distribution is discussed. Numerical simulations using ANSYS FLUENT are also carried out to check the reliability of the network model. It is found that firstly, the proposed correlation of hydraulic resistance can capture the flow characteristics with high accuracy and the flow distributions predicted by the network model fit well with the simulation results for 2-D ordered packing structures with mono-sized and dual-sized particles and disordered packing structures with mono-sized particles. Secondly, it is revealed that, the packing form and the pore dimension have a significant effect on the flow distribution. Thirdly, the flow rate in a certain channel is dependent on the hydraulic resistances of the adjacent channels rather than just on itself.
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| 10. |
- Wang, Jingyu, et al.
(författare)
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Assessment of flow pattern and temperature profiles by residence time distribution in typical structured packed beds
- 2020
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Ingår i: Numerical Heat Transfer; Part A: Applications. - : Informa UK Limited. - 1040-7782 .- 1521-0634. ; 77:6, s. 559-578
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Tidskriftsartikel (refereegranskat)abstract
- The flow and temperature fields in packed beds are rather complex but are of great importance since they will influence macroscopic parameters and the overall performance of the packed bed system. Regions with either too high or too low velocity are not preferred since they will decrease the heat and mass transfer characteristics of packed beds. The residence time distribution (RTD) is a way to assess the characteristics of the flow maldistribution, where a narrower distribution is closer to the ideal plug flow with less dispersion. In this article, the RTD in three typical structured packed beds, namely, the simple cubic (SC) packing, the body-centered cubic (BCC) packing and the face-centered cubic (FCC) packing, are studied by using ANSYS FLUENT. Results show that, firstly, the RTD curve can be used to diagnose the flow pattern in packed beds where the skewed peak indicates the channeling effect and a long tail relates to recirculation. It is revealed secondly that, FCC packing has the narrowest RTD curve in the studied structures, BCC packing comes second and SC packing has the flattest RTD curve, which demonstrates that the flow uniformity in FCC packing is the best. For the same packing form, the flow is less maldistributed at higher velocity. Finally, it is shown that the packing form with less dispersion, which behaves more like the ideal plug flow, has a more uniform distribution of the particle-to-fluid heat transfer coefficient near the particle surface.
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| 11. |
- Wang, Jingyu, et al.
(författare)
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Hydraulic and heat transfer characteristics in structured packed beds with methane steam reforming reaction for energy storage
- 2021
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Ingår i: International Communications in Heat and Mass Transfer. - : Elsevier BV. - 0735-1933. ; 121
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Tidskriftsartikel (refereegranskat)abstract
- Packed beds with methane steam reforming reaction (MSR) can be used as thermochemical storage devices. The packing configuration can have a significant effect on the flow distribution which will further influence the heat/mass transfer, dispersion and reaction characteristics. In the present paper, the hydraulic, dispersion, heat/mass transfer and the MSR reaction properties are investigated in packed beds with the simple-cubic (SC) packing, the body-centered cubic (BCC) packing and face-centered cubic (FCC) packing forms. ANSYS FLUENT integrated with user defined scalars (UDS) and user defined functions (UDF) are used to perform the simulations. Results show that firstly, the residence time distribution (RTD) can be used to evaluate the dispersion property in packed beds where a narrower RTD curve reflects a more uniform velocity distribution with less dispersion. Secondly it is found that, regions with backflow are not beneficial for heat/mass transfer and chemical reactions from two aspects. One is that the heat transfer between the main fluid and the particle surfaces is weak and low temperature of the particles will reduce the reaction rates. The other is that the poor species transport will prevent the reactant to flow into the reaction region and the products cannot be taken away by the main flow timely, which will have a negative effect on the reaction. Thirdly, it is revealed that, the dimensionless variation of the residence time distribution (DVRTD) can reflect the heat/mass transfer and reaction performances, where a smaller DVRTD corresponds to better heat/mass transfer and higher reaction rates.
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| 12. |
- WANG, Jingyu, et al.
(författare)
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Numerical study of flow inhomogeneity and heat transfer enhancement in structured packed beds
- 2020
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Ingår i: Thermal Science. - 0354-9836. ; 24:6 PART A, s. 3533-3542
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Tidskriftsartikel (refereegranskat)abstract
- Packed beds are widely used in engineering applications due to their high specific surface area and good heat transfer characteristics. A grille-sphere composite packed bed is proposed previously and has been proved to have higher overall heat transfer coefficient than the simple cubic packing structure. In the present paper, the flow inhomogeneities in both the grille-sphere composite packed bed and the simple cubic packing are studied and the relationship between the flow inhomogeneity and the heat transfer characteristics is revealed by numerical simulations. The simulations are performed on ANSYS FLUENT software. The turbulence flow is modelled by the renormalization group k- model. Both dispersion of the velocity distribution and the residence time distribution are employed to assess the flow maldistribution. When the inlet velocity equals 2.17 m/s, the variance of the residence time distribution of the composite packed bed is 5.91% smaller than that of the simple cubic packing while the Nusselt number is 10.64% higher. The results indicate that less flow maldistribution can lead to heat transfer enhancement.
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