Exploring the Development and Research Focus of Cognitive Load Theory, as Described by Its Founders: Interviewing John Sweller, Fred Paas, and Jeroen van Merriënboer

This manuscript presents an interview with John Sweller, Fred Paas, and Jeroen van Merrienboer about cognitive load theory. It presents the views of these main founders of the theory on the progress from the first major publication on the theory in 1998 (Sweller, Van Merrienboer, & Paas, Educational Psychology Review, 10(3), 251–296, 1998) to the current publication, 20 years later in 2018 (Sweller, Van Merrienboer, & Paas, Educational Psychology Review, https://doi.org/10.1007/s10648-019-09465-5, 2019). More specifically, the interview focuses on challenges and opportunities of cognitive load theory and the associated instructional design research, the role of measurement of cognitive load and mental efficiency, as well as the instructional control of cognitive load in the cognitive load research. The interview is concluded with suggestions and advice for young researchers

Study on rainfall infiltration characteristic parameters of unsaturated soil

The study of the rainfall infiltration mechanism of unsaturated soil has always been a hot issue in the field of geotechnical engineering. It is worth studying which parameters should be introduced to characterize the infiltration characteristics of unsaturated soil in the calculation and analysis of rainfall infiltration. In this paper, the Fredlund–Xing model was quoted in the SEEP/W module of the Geostudio software, and the transient numerical calculation of rainfall infiltration under the same rainfall duration T and different rainfall intensity I was carried out for a soil column. Three infiltration characteristic parameters were introduced: rainfall infiltration front depth WF, suction reduction depth MRn, and section infiltration rate IR. The variation of these three parameters and rainfall intensity I during rainfall were sorted out and analyzed; it is indicated that WF increases with the extension of rainfall duration. MRn decreases with the increase of suction reduction rate n%, and when the rainfall duration is 24 h, the maximum depth of the soil column affected by rainfall is approximately 35% of the total depth. IR is mainly affected by the rainfall intensity I and the saturation permeability coefficient ks. There is a limit value for the influence of I on WF, MRn, and IR, and the limit rainfall intensity under the calculation conditions in this paper is I = 2.5ks

Metabolism and Pharmacokinetics of Novel Selective Vascular Endothelial Growth Factor Receptor-2 Inhibitor Apatinib in Humans

ABSTRACT Apatinib is a new oral antiangiogenic molecule that inhibits vascular endothelial growth factor receptor-2. The present study aimed to determine the metabolism, pharmacokinetics, and excretion of apatinib in humans and to identify the enzymes responsible for its metabolism. The primary routes of apatinib biotransformation included E-and Z-cyclopentyl-3-hydroxylation, N-dealkylation, pyridyl-25-N-oxidation, 16-hydroxylation, dioxygenation, and O-glucuronidation after 3-hydroxylation. Nine major metabolites were confirmed by comparison with reference standards. The total recovery of the administered dose was 76.8% within 96 hours postdose, with 69.8 and 7.02% of the administered dose excreted in feces and urine, respectively. About 59.0% of the administered dose was excreted unchanged via feces. Unchanged apatinib was detected in negligible quantities in urine, indicating that systemically available apatinib was extensively metabolized. The major circulating metabolite was the pharmacologically inactive E-3-hydroxy-apatinib-O-glucuronide (M9-2), the steady-state exposure of which was 125% that of the apatinib. The steady-state exposures of E-3-hydroxy-apatinib (M1-1), Z-3-hydroxy-apatinib (M1-2), and apatinib-25-N-oxide (M1-6) were 56, 22, and 32% of parent drug exposure, respectively. Calculated as pharmacological activity index values, the contribution of M1-1 to the pharmacology of the drug was 5.42 to 19.3% that of the parent drug. The contribution of M1-2 and M1-6 to the pharmacology of the drug was less than 1%. Therefore, apatinib was a major contributor to the overall pharmacological activity in humans. Apatinib was metabolized primarily by CYP3A4/ 5 and, to a lesser extent, by CYP2D6, CYP2C9, and CYP2E1. UGT2B7 was the main enzyme responsible for M9-2 formation. Both UGT1A4 and UGT2B7 were responsible for Z-3-hydroxyapatinib-O-glucuronide (M9-1) formation

Experimental observation of the TJI-initiated HPDI gas combustion: Vertically crossed flame jet and methane jet

In the field of natural gas marine engines, the high-pressure direct injection (HPDI) technology is widely used to achieve emission reduction while maintaining equivalent thermal efficiency and power output compared to diesel engines. In these engines, the in-cylinder combustion is primarily initiated by the diesel spray flame near the top dead center (TDC). In the present work, pre-chamber turbulent jet ignition (TJI) is employed to substitute diesel injection to initiate the combustion of HPDI methane jets. The optical experiments of ignition and flame development in the TJI-HPDI system with various injector configurations and injection/ignition control parameters are conducted in a constant-volume combustion chamber (CVCC). It is revealed that with the increase of injection-ignition delay(ti), three ignition modes are observed sequentially: methane jet suppresses ignition, methane jet first suppresses ignition then promotes flame propagation, and direct ignition and promoted flame propagation. The effect of various injection-ignition delays and injection pulse width were explored. The injection-ignition delay significantly influences the combustion characteristics such as heat release rate, while the injection pulse width influences the duration of the lifted jet flame. The flame lift-off length first decreases and then increases due to variations in thermodynamic conditions and oxygen concentration. With a larger-nozzle injector, the critical injection-ignition delay to initiate the main chamber combustion is significantly reduced. Moreover, the use of different nozzle diameters leads to varying levels of turbulent intensity in the methane jet, which in turn affects the combustion behavior

A Review of Vision-Based Autonomous UAV Landing Research

UAVs are widely used in rescue and disaster relief, and autonomous landing is one of the key technologies in the application of UAVs. Due to the influence of accuracy and interference, traditional navigation technologies such as GPS and INS often fail to meet the navigation requirements during landing. Vision-based autonomous landing system has the advantages of strong autonomy, low cost, low power consumption and strong anti-jamming capability, which is suitable for application in the navigation of the autonomous landing phase of UAVs. This paper summarises the current research results in the field of vision-based autonomous landing for UAVs. The camera installation locations and landing platform types are sorted out, the key technologies are compared and analysed, and the future development trends are pointed out

A Fast Binocular Localisation Method for AUV Docking

Docking technology plays a critical role in realising the long-time operation of autonomous underwater vehicles (AUVs). In this study, a binocular localisation method for AUV docking is presented. An adaptively weighted OTSU method is developed for feature extraction. The foreground object is extracted precisely without mixing or missing lamps, which is independent of the position of the AUV relative to the station. Moreover, this extraction process is more precise compared to other segmentation methods with a low computational load. The mass centre of each lamp on the binary image is used as matching feature for binocular vision. Using this fast feature matching method, the operation frequency of the binocular localisation method exceeds 10 Hz. Meanwhile, a relative pose estimation method is suggested for instances when the two cameras cannot capture all the lamps. The localisation accuracy of the distance in the heading direction as measured by the proposed binocular vision algorithm was tested at fixed points underwater. A simulation experiment using a ship model has been conducted in a laboratory pool to evaluate the feasibility of the algorithm. The test result demonstrates that the average localisation error is approximately 5 cm and the average relative location error is approximately 2% in the range of 3.6 m. As such, the ship model was successfully guided to the docking station for different lateral deviations

Characteristics of Energy Dissipation in T-Shaped Fractured Rocks under Different Loading Rates

T-shaped fractured rocks in the engineering rock mass with different inclination angles, quantities, and cross patterns will cause slope landslides, cavern collapse, roof fall, and other disasters under the action of external forces. Deformation evolution of the T-shaped fractured rock is also significant for monitoring the stability of rock engineering structures. In this paper, the compression test of T-shaped fracture specimens was carried out under different loading rates. By modulating both the fracture inclination angle and the loading rate, the attributes pertaining to energy dissipation in the T-shaped fractured specimen were scrupulously scrutinized and subsequently expounded upon. The difference in the energy characteristics between fractured rock and intact rock was investigated to understand the deformation evolution of T-shaped fractured rock samples. The results show that when the fracture angle is 45° and 90°, the elastic strain energy and dissipated energy decrease as the secondary fracture angle increases. At the peak point, as the secondary fracture angle increases from 0°, the total absorbed energy, elastic strain energy, and dissipated energy of the T-shaped fractured rock increase, the ratio Ue/U of elastic strain energy to total energy increases, and the ratio Ud/U of dissipated energy to total energy decreases. The increase in loading rate leads to an increase in Ue/U and a decrease in Ud/U at the peak point of the T-shaped fractured rock specimen. The increase in loading rate leads to an increase in the total absorbed energy and elastic energy at the peak point of the T-shaped fractured rock, while the dissipated energy decreases. Investigative endeavors into the mechanics and energetic attributes of T-shaped fractured rocks bestow pragmatic and directive significance upon the safety assessment and stability prognostication of sundry geological undertakings

CARNet: Context-Aware Residual Learning for JPEG-LS Compressed Remote Sensing Image Restoration

JPEG-LS (a lossless (LS) compression standard developed by the Joint Photographic Expert Group) compressed image restoration is a significant problem in remote sensing applications. It faces the following two challenges: first, bridging small pixel-value gaps from wide numerical ranges; and second, removing banding artifacts in the condition of lacking available context information. As far as we know, there is currently no research dealing with the above issues. Hence, we develop this initial line of work on JPEG-LS compressed remote sensing image restoration. We propose a novel CNN model called CARNet. Its core idea is a context-aware residual learning mechanism. Specifically, it realizes residual learning for accurate restoration by adopting a scale-invariant baseline. It enables large receptive fields for banding artifact removal through a context-aware scheme. Additionally, it eases the information flow among stages by utilizing a prior-guided feature-fusion mechanism. Alternatively, we design novel R IQA models to provide a better restoration performance assessment for our study by utilizing gradient priors of JPEG-LS banding artifacts. Furthermore, we prepare a new dataset of JPEG-LS compressed remote sensing images to supplement existing benchmark data. Experiments show that our method sets the state-of-the-art for JPEG-LS compressed remote sensing image restoration

Low-Temperature Superplasticity and Deformation Mechanism of Ti-6Al-4V Alloy

The low-temperature superplastic tensile behavior and the deformation mechanisms of Ti-6Al-4V alloy are investigated in this paper. Through the experiments carried out, elongation to failure (δ) is calculated and a set of values are derived that subsequently includes the strain rate sensitivity exponent (m), deformation activation energy (Q) at low-temperature superplastic deformation, and the variation of δ, m and Q at different strain rates and temperatures. Microstructures are observed before and after superplastic deformation. The deformation mechanism maps incorporating the density of dislocations inside grains at temperatures of 973 and 1123 K are drawn respectively. By applying the elevated temperature deformation mechanism maps based on Burgers vector compensated grain size and modulus compensated stress, the dislocation quantities and low-temperature superplastic deformation mechanisms of Ti-6Al-4V alloy at different temperatures within appropriate processing regime are elucidated