| 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. |
- Luo, Yifei, et al.
(författare)
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Technology Roadmap for Flexible Sensors
- 2023
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Ingår i: ACS Nano. - : American Chemical Society. - 1936-0851 .- 1936-086X. ; 17:6, s. 5211-5295
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Forskningsöversikt (refereegranskat)abstract
- Humans rely increasingly on sensors to address grand challenges and to improve quality of life in the era of digitalization and big data. For ubiquitous sensing, flexible sensors are developed to overcome the limitations of conventional rigid counterparts. Despite rapid advancement in bench-side research over the last decade, the market adoption of flexible sensors remains limited. To ease and to expedite their deployment, here, we identify bottlenecks hindering the maturation of flexible sensors and propose promising solutions. We first analyze challenges in achieving satisfactory sensing performance for real-world applications and then summarize issues in compatible sensor-biology interfaces, followed by brief discussions on powering and connecting sensor networks. Issues en route to commercialization and for sustainable growth of the sector are also analyzed, highlighting environmental concerns and emphasizing nontechnical issues such as business, regulatory, and ethical considerations. Additionally, we look at future intelligent flexible sensors. In proposing a comprehensive roadmap, we hope to steer research efforts towards common goals and to guide coordinated development strategies from disparate communities. Through such collaborative efforts, scientific breakthroughs can be made sooner and capitalized for the betterment of humanity.
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| 3. |
- Chen, Shouzhi, et al.
(författare)
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Influences of Shifted Vegetation Phenology on Runoff Across a Hydroclimatic Gradient
- 2022
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Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Climate warming has changed vegetation phenology, and the phenology-associated impacts on terrestrial water fluxes remain largely unquantified. The impacts are linked to plant adjustments and responses to climate change and can be different in different hydroclimatic regions. Based on remote sensing data and observed river runoff of hydrological station from six river basins across a hydroclimatic gradient from northeast to southwest in China, the relative contributions of the vegetation (including spring and autumn phenology, growing season length (GSL), and gross primary productivity) and climatic factors affecting the river runoffs over 1982–2015 were investigated by applying gray relational analysis (GRA). We found that the average GSLs in humid regions (190–241 days) were longer than that in semi-humid regions (186–192 days), and the average GSLs were consistently extended by 4.8–13.9 days in 1982–2015 period in six river basins. The extensions were mainly linked to the delayed autumn phenology in the humid regions and to advanced spring phenology in the semi-humid regions. Across all river basins, the GRA results showed that precipitation (r = 0.74) and soil moisture (r = 0.73) determine the river runoffs, and the vegetation factors (VFs) especially the vegetation phenology also affected the river runoffs (spring phenology: r = 0.66; GSL: r = 0.61; autumn phenology: r = 0.59), even larger than the contribution from temperature (r = 0.57), but its relative importance is climatic region-dependent. Interestingly, the spring phenology is the main VF in the humid region for runoffs reduction, while both spring and autumn growth phenology are the main VFs in the semi-humid region, because large autumn phenology delay and less water supply capacity in spring amplify the effect of advanced spring phenology. This article reveals diverse linkages between climatic and VFs, and runoff in different hydroclimatic regions, and provides insights that vegetation phenology influences the ecohydrology process largely depending on the local hydroclimatic conditions, which improve our understanding of terrestrial hydrological responses to climate change.
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| 4. |
- Liang, Wang, et al.
(författare)
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Life cycle assessment of blast furnace ironmaking processes : A comparison of fossil fuels and biomass hydrochar applications
- 2023
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 345
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Tidskriftsartikel (refereegranskat)abstract
- The impact of the iron and steel production process on the ecological environment cannot be ignored. This study aims to assess the impact of life cycle assessment on the traditional fossil fuel blast furnace ironmaking process and the biomass hydrochar blast furnace ironmaking process. The Simapro v9.0 software is used to comprehensively evaluate the life cycle impacts of biomass hydrochar in the blast furnace ironmaking process. The results show that the life cycle impact categories of the blast furnace ironmaking process mainly include global warming, non-renewable energy and respiratory inorganics. The global warming impact of the ironmaking process using hydrochar is 2054.00 kg CO2 eq, which is 420.61 kg CO2 eq less than that of traditional blast furnace ironmaking process. The global warming impact is mainly reflected in the emission of CO2 gas, and the main source is the generation of blast furnace gas and the use of sinter. The respiratory inorganics impact is mainly manifested in the emission of nitrogen oxides, sulfur oxides and particulates, which mainly comes from the mining of iron ore and the production of sinter. The non-renewable energy impact mainly comes from the coal resources, and the use of other renewable energy such as biomass energy is an important way to reduce the impact. Therefore, biomass hydrochar used in the metallurgical process is more suitable for sustainable devel-opment of the ecological environment.
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| 5. |
- Wang, Guangwei, et al.
(författare)
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Application of catalysts in biomass hydrothermal carbonization for the preparation of high-quality blast furnace injection fuel
- 2023
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Ingår i: Energy. - : Elsevier BV. - 0360-5442 .- 1873-6785. ; 283
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Tidskriftsartikel (refereegranskat)abstract
- The low energy density of biomass is a crucial limitation for their application in the steel industry. This study used catalyst-catalysed hydrothermal carbonization (HTC) to prepare higher-quality hydrochar from biomass. The effects of acid-base homogeneous catalysts (Fe(NO3)3·9H2O and CaO), liquid phase product (circulating water) and carbonization temperatures on the physicochemical properties and microscopic morphology of hydrochars were investigated. The results showed that higher carbonization temperature, circulating water and Fe(NO3)3·9H2O all raised the higher heating value (HHV) of hydrochar. When 4% of Fe(NO3)3·9H2O was added, the HHV of hydrochar reached 30.05 MJ/kg, which was 1.15 times higher than without catalysts. The above three conditions can also make the ordering degree in the carbonaceous structure lower ordered and enhance the reaction performance of the hydrochar. Meanwhile, the addition of Fe(NO3)3·9H2O at 240 °C can reduce the hydrochar ignition and burnout temperatures and enhance the combustion performance. Moreover, it was demonstrated that circulating water promoted the HTC more than deionized water. In conclusion, adding Fe(NO3)3·9H2O or circulating water to the HTC process can produce higher-quality hydrochar.
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| 6. |
- Wang, Guangwei, et al.
(författare)
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Preparation of Biomass Hydrochar and Application Analysis of Blast Furnace Injection
- 2023
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Ingår i: Energies. - : MDPI AG. - 1996-1073. ; 16:3
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Tidskriftsartikel (refereegranskat)abstract
- Hydrothermal carbonization (HTC) technology was used to carbonize and improve biomass raw material to obtain hydrochar. The effects of HTC temperature and holding time on the yield, composition, structure, combustion behavior, and safety of hydrochar were studied systematically. In addition, the results show that with the increase in HTC temperature and the prolongation of holding time, the yield of hydrochar gradually reduces, the fixed carbon content of hydrochar increases, the volatile content decreases, and a large number of ash and alkali metals enter the liquid phase and are removed. Further, the analysis of the combustion properties and the structure of hydrochar can be observed in that, as the HTC process promotes the occurrence of polymerization reactions, the specific surface area gradually reduces, the degree of carbon ordering increases, and the combustion curve moves toward the high-temperature zone and gradually approaches bituminous coal. Since biomass hydrochar has the characteristic of being carbon neutral, blast furnace injection hydrochar can reduce CO2 emissions, and every 1 kg/tHM of biomass hydrochar can reduce CO2 emissions by 1.95 kg/tHM.
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| 7. |
- Wu, Jianlong, et al.
(författare)
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Study on Direct Reduction in Carbon-Bearing Pellets Using Biochar
- 2023
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Ingår i: Sustainability. - : MDPI AG. - 2071-1050. ; 15:24
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Tidskriftsartikel (refereegranskat)abstract
- As a renewable, carbon-neutral raw material, the application of biomass in steel production is conducive to reducing greenhouse gas emissions and achieving green and sustainable development in the steel industry. The heating and reduction process of a rotary hearth furnace was simulated under laboratory conditions to roast and reduce biochar carbon-bearing pellets with coke powder and anthracite carbon-bearing pellets as a comparison. This was conducted to investigate the impact of biochar as a reducing agent on the direct reduction in carbon-bearing pellets. Under various reduction temperatures, carbon/oxygen ratios, and reduction times, tests were conducted on the compressive strength and metallization rate of carbon-bearing pellets made using typical binder bentonite. Results show that with the increase in reduction temperature, the metallization rate of pellets increases, while the compressive strength initially decreases and then increases, reaching the lowest point at 900 degrees C and 1000 degrees C. When the ratio of carbon to oxygen is between 0.7 and 0.9 and the reduction time is between 15 and 25 min, carbon-bearing pellets meet the requirements of both the metallization rate and the strength, with the metallization rate above 80%. However, severe volume swelling and low strength were observed in biochar carbon-bearing pellets at 900 degrees C and 1000 degrees C, which negatively impacted multi-layered charging and heat transfer efficiency in the blast furnace. Therefore, a novel laboratory-prepared binder was introduced in the preparation process of biochar carbon-bearing pellets at an appropriate addition ratio of 5-8%. Without producing any swelling concerns, the inclusion of this binder considerably improved the compression strength and metallization rate of the pellets, enabling them to fulfill the standards for raw materials in the blast furnace.
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| 8. |
- Xu, Jiangchang, et al.
(författare)
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A review on AI-based medical image computing in head and neck surgery
- 2022
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Ingår i: Physics in Medicine and Biology. - : IOP Publishing. - 0031-9155 .- 1361-6560. ; 67:17, s. 17TR01-
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Forskningsöversikt (refereegranskat)abstract
- Head and neck surgery is a fine surgical procedure with a complex anatomical space, difficult operation and high risk. Medical image computing (MIC) that enables accurate and reliable preoperative planning is often needed to reduce the operational difficulty of surgery and to improve patient survival. At present, artificial intelligence, especially deep learning, has become an intense focus of research in MIC. In this study, the application of deep learning-based MIC in head and neck surgery is reviewed. Relevant literature was retrieved on the Web of Science database from January 2015 to May 2022, and some papers were selected for review from mainstream journals and conferences, such as IEEE Transactions on Medical Imaging, Medical Image Analysis, Physics in Medicine and Biology, Medical Physics, MICCAI, etc. Among them, 65 references are on automatic segmentation, 15 references on automatic landmark detection, and eight references on automatic registration. In the elaboration of the review, first, an overview of deep learning in MIC is presented. Then, the application of deep learning methods is systematically summarized according to the clinical needs, and generalized into segmentation, landmark detection and registration of head and neck medical images. In segmentation, it is mainly focused on the automatic segmentation of high-risk organs, head and neck tumors, skull structure and teeth, including the analysis of their advantages, differences and shortcomings. In landmark detection, the focus is mainly on the introduction of landmark detection in cephalometric and craniomaxillofacial images, and the analysis of their advantages and disadvantages. In registration, deep learning networks for multimodal image registration of the head and neck are presented. Finally, their shortcomings and future development directions are systematically discussed. The study aims to serve as a reference and guidance for researchers, engineers or doctors engaged in medical image analysis of head and neck surgery.
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| 9. |
- Xu, Jiangchang, et al.
(författare)
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Automatic segmentation of orbital wall from CT images via a thin wall region supervision-based multi-scale feature search network
- 2023
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Ingår i: International Journal of Computer Assisted Radiology and Surgery. - : Springer Nature. - 1861-6410 .- 1861-6429. ; 18:11, s. 2051-2062
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Orbital wall segmentation is critical for orbital measurement and reconstruction. However, the orbital floor and medial wall are made up of thin walls (TW) with low gradient values, making it difficult to segment the blurred areas of the CT images. Clinically, doctors have to manually repair the missing parts of TW, which is time-consuming and laborious. Methods: To address these issues, this paper proposes an automatic orbital wall segmentation method based on TW region supervision using a multi-scale feature search network. First of all, in the encoding branch, the densely connected atrous spatial pyramid pooling based on the residual connection is adopted to achieve a multi-scale feature search. Then, for feature enhancement, multi-scale up-sampling and residual connection are applied to perform skip connection of features in multi-scale convolution. Finally, we explore a strategy for improving the loss function based on the TW region supervision, which effectively increases the TW region segmentation accuracy. Results: The test results show that the proposed network performs well in terms of automatic segmentation. For the whole orbital wall region, the Dice coefficient (Dice) of segmentation accuracy reaches 96.086 ± 1.049%, the Intersection over Union (IOU) reaches 92.486 ± 1.924%, and the 95% Hausdorff distance (HD) reaches 0.509 ± 0.166 mm. For the TW region, the Dice reaches 91.470 ± 1.739%, the IOU reaches 84.327 ± 2.938%, and the 95% HD reaches 0.481 ± 0.082 mm. Compared with other segmentation networks, the proposed network improves the segmentation accuracy while filling the missing parts in the TW region. Conclusion: In the proposed network, the average segmentation time of each orbital wall is only 4.05 s, obviously improving the segmentation efficiency of doctors. In the future, it may have a practical significance in clinical applications such as preoperative planning for orbital reconstruction, orbital modeling, orbital implant design, and so on.
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| 10. |
- Yin, Xiaojun, et al.
(författare)
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In-depth comparison of methanol port and direct injection strategies in a methanol/diesel dual fuel engine
- 2023
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Ingår i: Fuel Processing Technology. - : Elsevier BV. - 0378-3820. ; 241
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Tidskriftsartikel (refereegranskat)abstract
- For methanol/diesel dual-fuel combustion, there are two different methanol injection implementations: port injection into the intake manifold and direct injection into cylinder. In this work, an experimental comparison was conducted for the two methanol injection strategies to study the effects of the methanol-energy-substation ratio (ESR) and diesel injection timing on the fuel-air mixing and combustion characteristics. The results showed that the ignition delay was increased with ESR due to the cooling effect of methanol evaporation in the cylinder. The combustion duration under methanol direct injection condition was much shorter than that of the methanol port injection strategy. The methanol direct injection strategy had a more controllable and stable heat release than that of methanol port injection strategy. The maximum ESR could reach up to 96.0% in the methanol direct injection strategy. The methanol direct injection strategy had a better fuel economy, and its maximum indicated thermal efficiency could reach up to 41.55% at 50% ESR. The methanol direct injection strategy yielded higher NOx emissions than that with the port injection strategy, accompanied by a mild increase of soot emissions. Compared with methanol port injection, the methanol direct injection strategy exhibits lower CO emissions, however, it suffers from higher HC emissions.
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