| 1. |
- Haubro Andersen, Pia, et al.
(författare)
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Towards Machine Recognition of Facial Expressions of Pain in Horses
- 2021
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Ingår i: Animals. - : MDPI. - 2076-2615. ; 11:6
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Forskningsöversikt (refereegranskat)abstract
- Simple Summary Facial activity can convey valid information about the experience of pain in a horse. However, scoring of pain in horses based on facial activity is still in its infancy and accurate scoring can only be performed by trained assessors. Pain in humans can now be recognized reliably from video footage of faces, using computer vision and machine learning. We examine the hurdles in applying these technologies to horses and suggest two general approaches to automatic horse pain recognition. The first approach involves automatically detecting objectively defined facial expression aspects that do not involve any human judgment of what the expression "means". Automated classification of pain expressions can then be done according to a rule-based system since the facial expression aspects are defined with this information in mind. The other involves training very flexible machine learning methods with raw videos of horses with known true pain status. The upside of this approach is that the system has access to all the information in the video without engineered intermediate methods that have filtered out most of the variation. However, a large challenge is that large datasets with reliable pain annotation are required. We have obtained promising results from both approaches. Automated recognition of human facial expressions of pain and emotions is to a certain degree a solved problem, using approaches based on computer vision and machine learning. However, the application of such methods to horses has proven difficult. Major barriers are the lack of sufficiently large, annotated databases for horses and difficulties in obtaining correct classifications of pain because horses are non-verbal. This review describes our work to overcome these barriers, using two different approaches. One involves the use of a manual, but relatively objective, classification system for facial activity (Facial Action Coding System), where data are analyzed for pain expressions after coding using machine learning principles. We have devised tools that can aid manual labeling by identifying the faces and facial keypoints of horses. This approach provides promising results in the automated recognition of facial action units from images. The second approach, recurrent neural network end-to-end learning, requires less extraction of features and representations from the video but instead depends on large volumes of video data with ground truth. Our preliminary results suggest clearly that dynamics are important for pain recognition and show that combinations of recurrent neural networks can classify experimental pain in a small number of horses better than human raters.
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| 2. |
- Huang, Liming, 1993, et al.
(författare)
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Moisture and ion transport properties in blended pastes and their relation to the refined pore structure
- 2022
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Ingår i: Cement and Concrete Research. - : Elsevier BV. - 0008-8846. ; 161:106949
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a study of the moisture transport properties in blended pastes measured by a new procedure and setup. The dependence of moisture transport coefficient on relative humidity (RH) is confirmed. The differences in the moisture dependency may be due to discrepancies in the critical RH for the percolation of liquid. Fly ash and slag increase the percentage of mesopores or “ink-bottle” pores with a mesoscale neck and they strongly reduce the pore connectivity in pastes. These effects cause the evident reduction in the moisture and chloride diffusivity. The additional replacement with limestone filler has little effect on the pore connectivity. The formation factor controls the moisture transport at the high RH interval, but the volume of small pores (middle capillary and mesopores) is the major determinant at a low RH interval. The relationship between water-binder ratio, pore structure and moisture transport or chloride migration coefficient is discussed.
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| 3. |
- Huang, Liming, 1993, et al.
(författare)
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New insights into the reaction of tricalcium silicate (C 3 S) with solutions to the end of the induction period
- 2022
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Ingår i: Cement and Concrete Research. - : Elsevier BV. - 0008-8846. ; 152
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Tidskriftsartikel (refereegranskat)abstract
- Although dissolution theory is widely used, in certain circumstance, it seems to be unable to explain the hydration of C3S. In this article, more attention is paid to the nucleation of hydration products. We find that the precipitation of C-S-H is a nonclassical nucleation process. It starts with nucleation of primary particles and then grows by particle attachment. A sharp increase in the reaction rate after induction period may come from the accelerating growth rate of C-S-H instead of dissolution of etch pits. The duration of induction period relates to the size of primary floc. Potassium salts influence the primary globule floc size and mitigate the effect from Al. The pH impacts ion species in solution to affect the dissolution and precipitation. A hypothesis regarding the dissolution of C3S and nucleation of C-S-H within the near-surface region may narrow the gap between dissolution theory and protective layer theory.
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| 4. |
- Huang, Liming, 1993, et al.
(författare)
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Non-destructive test system to monitor hydration and strength development of low CO2 concrete
- 2023
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Ingår i: Construction and Building Materials. - 0950-0618. ; 408
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Tidskriftsartikel (refereegranskat)abstract
- Application of supplementary cementitious materials for production of low CO2 concrete affects the reaction kinetics, which alters the setting time and strength development. The different early-age behavior is of concern for quality control of concrete. Non-destructive test is very useful for monitoring the quality of low CO2 binder systems. This paper presents a new technique to monitor the electrical conductivity and temperature at different depths of hydrating concrete. Indices from monitoring system (conductivity, maturity and formation factor) are compared with data from widely-used methods (ultrasonic pulse velocity, penetration resistance and isothermal calorimetry). Results show that indices from the system can replicate the hydration evolution, setting time and compressive strength of low CO2 concrete. Electrical conductivity of concrete is very sensitive to mineral reactions and it reflects the hydration kinetic consistent with evolution of heat release. Linear correlations are found for penetration resistance in relation to ultrasonic pulse velocity, formation factor and maturity, respectively. The effects of binder type and water-to-binder ratio on hardening are strongly dependent on temperature. The proposed approach enables to include all these factors in characterizing the hardening process of concrete onsite. It is shown that formation factor performs better than ultrasonic pulse velocity on indicating the setting process. Formation factor is also a good parameter for quantitative description of compressive strength development, which is independent of the binder types, mixture proportions and curing ages.
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| 5. |
- Huang, Liming, 1993, et al.
(författare)
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Recycling of the end-of-life lightweight aggregate concrete (LWAC) with a novel approach
- 2020
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526. ; 275
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Tidskriftsartikel (refereegranskat)abstract
- This work proposed an environmental-friendly approach for high-grade recycling of the end-of-life LWAC. The mechanical performance of mortar with recycled powder (RP), mortar with recycled fine aggregate (RFA) and recycled lightweight aggregate concrete (RLWAC) were investigated. Microstructure of mortar and RLWAC was detected to identify the properties of interfacial transition zone (ITZ). RP can prolong the setting of reference cement and the 10% dosage is better than 2% in not only retarding effect but also strength development. An appropriate content of RFA is beneficial for compressive strength. Replacing standard sand with 10% RFA increases the compressive strength of mortar by approximately 10%. However, a high replacement content (40%) of RFA brings about a reduction of compressive strength. The amount of RFA below 20% will not increase the dry shrinkage of mortar. The compressive strength of RLWAC is reduced by 10% RLWA but it has a significant increase when the replacement content reaches 30%. In mortar with RFA, cracks initiate from the ITZ of new sand and new paste and few cracks generate from old paste and old sand. Four types of ITZ that have distinct features are observed between cement paste and LWA in RLWAC.
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| 6. |
- Li, Zhen, et al.
(författare)
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Using alumina-rich sludge and phosphogypsum manufactures low-CO 2 cement
- 2021
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Ingår i: Construction and Building Materials. - : Elsevier BV. - 0950-0618. ; 288
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Tidskriftsartikel (refereegranskat)abstract
- Calcium sulfoaluminate-belite (CŜAB) cement has been proposed as a low-CO cement for substituting ordinary Portland cement (OPC). The aim of this work was to study synthesis of CŜAB cement from two industrial wastes, namely Alumina-rich sludge (AS) and phosphogypsum (PG). The main phases of the synthesized cement were ye'elimite, larnite, ternesite and anhydrite. The properties of CŜAB cement were investigated through the test of compressive strength, setting time and hydration products. We found that the optimal procedure was burning at 1150 °C for 1 h which needs much lower energy than traditional production. CŜAB cement could reach 39.4 MPa at 28 d hydration, when basicity factor, the ratio of aluminum to sulfur and aluminum to silicon ratio were 0.8, 2.5 and 3 respectively. Blending phosphogypsum into clinker, made paste get a much higher compressive strength (53.2 MPa at 28 d). Adding phosphogypsum to CŜAB cement hindered hydration process of cement and decreased hydration products except for ettringite. Production of this cement is beneficial to recycle industrial wastes and reduce CO emission. This is meaningful for further development of cement industry. 2 2
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