| 1. |
- Gu, Song, et al.
(author)
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Gaze Estimation via a Differential Eyes' Appearances Network with a Reference Grid
- 2021
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In: ENGINEERING. - : Elsevier BV. - 2095-8099. ; 7:6, s. 777-786
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Journal article (peer-reviewed)abstract
- A person's eye gaze can effectively express that person's intentions. Thus, gaze estimation is an important approach in intelligent manufacturing to analyze a person's intentions. Many gaze estimation methods regress the direction of the gaze by analyzing images of the eyes, also known as eye patches. However, it is very difficult to construct a person-independent model that can estimate an accurate gaze direction for every person due to individual differences. In this paper, we hypothesize that the difference in the appearance of each of a person's eyes is related to the difference in the corresponding gaze directions. Based on this hypothesis, a differential eyes' appearances network (DEANet) is trained on public datasets to predict the gaze differences of pairwise eye patches belonging to the same individual. Our proposed DEANet is based on a Siamese neural network (SNNet) framework which has two identical branches. A multi-stream architecture is fed into each branch of the SNNet. Both branches of the DEANet that share the same weights extract the features of the patches; then the features are concatenated to obtain the difference of the gaze directions. Once the differential gaze model is trained, a new person's gaze direction can be estimated when a few calibrated eye patches for that person are provided. Because person specific calibrated eye patches are involved in the testing stage, the estimation accuracy is improved. Furthermore, the problem of requiring a large amount of data when training a person-specific model is effectively avoided. A reference grid strategy is also proposed in order to select a few references as some of the DEANet's inputs directly based on the estimation values, further thereby improving the estimation accuracy. Experiments on public datasets show that our proposed approach outperforms the state-of-the-art methods.
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| 2. |
- Han, Ziming, et al.
(author)
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Three-Year Consecutive Field Application of Erythromycin Fermentation Residue Following Hydrothermal Treatment: Cumulative Effect on Soil Antibiotic Resistance Genes
- 2022
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In: Engineering. - : Elsevier BV. - 2095-8099. ; 15, s. 78-88
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Journal article (peer-reviewed)abstract
- Fermentation-based antibiotic production results in abundant nutrient-rich fermentation residue with high potential for recycling, but the high antibiotic residual concentration restricts its usefulness (e.g., in land application as organic fertilizer). In this study, an industrial-scale hydrothermal facility for the treatment of erythromycin fermentation residue (EFR) was investigated, and the potential risk of the long-term soil application of treated EFR promoting environmental antibiotic resistance development was evaluated. The treatment effectively removed bacteria and their DNA, and an erythromycin removal ratio of up to approximately 98% was achieved. The treated EFR was utilized as organic fertilizer for consecutive field applications from 2018 to 2020, with dosages ranging from 3750 to 15 000 kg∙hm−2, resulting in sub-inhibitory levels of erythromycin (ranging from 0.83–76.00 μg∙kg−1) in soils. Metagenomic shotgun sequencing was then used to characterize the antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and bacterial community composition of the soils. The soil ARG abundance and diversity did not respond to the treated EFR application in the first year, but gradually changed in the second and third year of application. The highest fold change in relative abundance of macrolide–lincosamide–streptogramin (MLS) and total ARGs were 12.59 and 2.75 times, compared with the control (CK; without application), respectively. The soil MGEs and taxonomic composition showed similar temporal trends to those of the ARGs, and appeared to assist in driving increasing ARG proliferation, as revealed by correlation analysis and structural equation models (SEMs). The relative abundance of particular erm resistance genes (RNA methyltransferase genes) increased significantly in the third year of treated EFR application. The close association of erm with MGEs suggested that horizontal gene transfer played a critical role in the observed erm gene enrichment. Metagenomic binning results demonstrated that the proliferation of mac gene-carrying hosts was responsible for the increased abundance of mac genes (efflux pump genes). This study shows that sub-inhibitory levels of erythromycin in soils had a cumulative effect on soil ARGs over time and emphasizes the importance of long-term monitoring for assessing the risk of soil amendment with treated industrial waste.
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| 3. |
- Hu, Junjie, et al.
(author)
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Flexibility Prediction of Aggregated Electric Vehicles and Domestic Hot Water Systems in Smart Grids
- 2021
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In: Engineering. - : Elsevier BV. - 2095-8099. ; 7:8, s. 1101-1114
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Journal article (peer-reviewed)abstract
- With the growth of intermittent renewable energy generation in power grids, there is an increasing demand for controllable resources to be deployed to guarantee power quality and frequency stability. The flexibility of demand response (DR) resources has become a valuable solution to this problem. However, existing research indicates that problems on flexibility prediction of DR resources have not been investigated. This study applied the temporal convolution network (TCN)-combined transformer, a deep learning technique to predict the aggregated flexibility of two types of DR resources, that is, elec-tric vehicles (EVs) and domestic hot water system (DHWS). The prediction uses historical power con-sumption data of these DR resources and DR signals (DSs) to facilitate prediction. The prediction can generate the size and maintenance time of the aggregated flexibility. The accuracy of the flexibility pre-diction results was verified through simulations of case studies. The simulation results show that under different maintenance times, the size of the flexibility changed. The proposed DR resource flexibility pre-diction method demonstrates its application in unlocking the demand-side flexibility to provide a reserve to grids.
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| 4. |
- Kovacs, Alexander, et al.
(author)
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Computational Design of Rare-Earth Reduced Permanent Magnets
- 2020
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In: ENGINEERING. - : ELSEVIER. - 2095-8099 .- 2096-0026. ; 6:2, s. 148-153
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Journal article (peer-reviewed)abstract
- Multiscale simulation is a key research tool in the quest for new permanent magnets. Starting with first principles methods, a sequence of simulation methods can be applied to calculate the maximum possible coercive field and expected energy density product of a magnet made from a novel magnetic material composition. Iron (Fe)-rich magnetic phases suitable for permanent magnets can be found by means of adaptive genetic algorithms. The intrinsic properties computed by ab intro simulations are used as input for micromagnetic simulations of the hysteresis properties of permanent magnets with a realistic structure. Using machine learning techniques, the magnet's structure can be optimized so that the upper limits for coercivity and energy density product for a given phase can be estimated. Structure property relations of synthetic permanent magnets were computed for several candidate hard magnetic phases. The following pairs (coercive field (T), energy density product (kJ.m(-3))) were obtained for iron-tin-antimony (Fe3Sn0.75Sb0.25): (0.49, 290), L1(0) -ordered iron-nickel (L1(0) FeNi): (1, 400), cobalt-iron-tantalum (CoFe6Ta): (0.87, 425), and manganese-aluminum (MnAl): (0.53, 80).
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| 5. |
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| 6. |
- Liu, Yaqiong, et al.
(author)
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An Auction-Based Approach for Multi-Agent Uniform Parallel Machine Scheduling with Dynamic Jobs Arrival
- 2024
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In: Engineering. - : Elsevier BV. - 2095-8099. ; 35, s. 32-45
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Journal article (peer-reviewed)abstract
- This paper addresses a multi-agent scheduling problem with uniform parallel machines owned by a resource agent and competing jobs with dynamic arrival times that belong to different consumer agents. All agents are self-interested and rational with the aim of maximizing their own objectives, resulting in intense resource competition among consumer agents and strategic behaviors of unwillingness to disclose private information. Within the context, a centralized scheduling approach is unfeasible, and a decentralized approach is considered to deal with the targeted problem. This study aims to generate a stable and collaborative solution with high social welfare while simultaneously accommodating consumer agents' preferences under incomplete information. For this purpose, a dynamic iterative auction-based approach based on a decentralized decision-making procedure is developed. In the proposed approach, a dynamic auction procedure is established for dynamic jobs participating in a realtime auction, and a straightforward and easy-to-implement bidding strategy without price is presented to reduce the complexity of bid determination. In addition, an adaptive Hungarian algorithm is applied to solve the winner determination problem efficiently. A theoretical analysis is conducted to prove that the proposed approach is individually rational and that the myopic bidding strategy is a weakly dominant strategy for consumer agents submitting bids. Extensive computational experiments demonstrate that the developed approach achieves high-quality solutions and exhibits considerable stability on largescale problems with numerous consumer agents and jobs. A further multi-agent scheduling problem considering multiple resource agents will be studied in future work.
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| 7. |
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| 8. |
- Luo, Zhengyi, et al.
(author)
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Demand Flexibility of Residential Buildings : Definitions, Flexible Loads, and Quantification Methods
- 2022
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In: Engineering. - : Elsevier Ltd. - 2095-8099. ; 16, s. 123-140
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Journal article (peer-reviewed)abstract
- This paper reviews recent research on the demand flexibility of residential buildings in regard to definitions, flexible loads, and quantification methods. A systematic distinction of the terminology is made, including the demand flexibility, operation flexibility, and energy flexibility of buildings. A comprehensive definition of building demand flexibility is proposed based on an analysis of the existing definitions. Moreover, the flexibility capabilities and operation characteristics of the main residential flexible loads are summarized and compared. Models and evaluation indicators to quantify the flexibility of these flexible loads are reviewed and summarized. Current research gaps and challenges are identified and analyzed as well. The results indicate that previous studies have focused on the flexibility of central air conditioning, electric water heaters, wet appliances, refrigerators, and lighting, where the proportion of studies focusing on each of these subjects is 36.7%, 25.7%, 14.7%, 9.2%, and 8.3%, respectively. These flexible loads are different in running modes, usage frequencies, seasons, and capabilities for shedding, shifting, and modulation, while their response characteristics are not yet clear. Furthermore, recommendations are given for the application of white-, black-, and grey-box models for modeling flexible loads in different situations. Numerous static flexibility evaluation indicators that are based on the aspects of power, temporality, energy, efficiency, economics, and the environment have been proposed in previous publications, but a consensus and standardized evaluation framework is lacking. This review can help readers better understand building demand flexibility and learn about the characteristics of different residential flexible loads, while also providing suggestions for future research on the modeling techniques and evaluation metrics of residential building demand flexibility.
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| 9. |
- Ma, Weimin, et al.
(author)
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In-Vessel Melt Retention of Pressurized Water Reactors : Historical Review and Future Research Needs
- 2016
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In: Engineering. - : Elsevier. - 2095-8099. ; 2:1, s. 103-111
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Research review (peer-reviewed)abstract
- A historical review of in-vessel melt retention (IVR) is given, which is a severe accident mitigation measure extensively applied in Generation III pressurized water reactors (PWRs). The idea of IVR actually originated from the back-fitting of the Generation II reactor Loviisa VVER-440 in order to cope with the core-melt risk. It was then employed in the new deigns such as Westinghouse AP1000, the Korean APR1400 as well as Chinese advanced PWR designs HPR1000 and CAP1400. The most influential phenomena on the IVR strategy are in-vessel core melt evolution, the heat fluxes imposed on the vessel by the molten core, and the external cooling of the reactor pressure vessel (RPV). For in-vessel melt evolution, past focus has only been placed on the melt pool convection in the lower plenum of the RPV; however, through our review and analysis, we believe that other in-vessel phenomena, including core degradation and relocation, debris formation, and coolability and melt pool formation, may all contribute to the final state of the melt pool and its thermal loads on the lower head. By looking into previous research on relevant topics, we aim to identify the missing pieces in the picture. Based on the state of the art, we conclude by proposing future research needs.
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| 10. |
- Pang, Shibao, et al.
(author)
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Dual-Dimensional Manufacturing Service Collaboration Optimization Toward Industrial Internet Platforms
- 2023
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In: ENGINEERING. - : Elsevier BV. - 2095-8099. ; 22, s. 34-48
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Journal article (peer-reviewed)abstract
- An Industrial Internet platform is acknowledged to be a requisite promoter for smart manufacturing, enabling physical manufacturing resources to be virtualized and permitting resources to collaborate in the form of services. As a central function of the platform, manufacturing service collaboration optimization is dedicated to establishing high-quality service collaboration solutions for manufacturing tasks. Such optimization is inseparable from the functional and amount requirements of a task, which must be satisfied when orchestrating services. However, existing manufacturing service collaboration optimization methods mainly focus on horizontal collaboration among services for functional demands and rarely consider vertical collaboration to cover the needed amounts. To address this gap, this paper proposes a dual-dimensional service collaboration methodology that combines functional and amount collaboration. First, a multi-granularity manufacturing service modeling method is presented to describe services. On this basis, a dual-dimensional manufacturing service collaboration optimization (DMSCO) model is formulated. In the vertical dimension, multiple functionally equivalent services form a service cluster to fulfill a subtask; in the horizontal dimension, complementary service clusters collaborate for the entire task. Service selection and amount distribution to the selected services are critical issues in the model. To solve the problem, a multi-objective memetic algorithm with multiple local search operators is tailored. The algorithm embeds a competition mechanism to dynamically adjust the selection probabilities of the local search operators. The experimental results demonstrate the superiority of the algorithm in terms of convergence, solution quality, and comprehensive metrics, in comparison with commonly used algorithms.
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