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The purpose of this study is to explore the impact of mobile learning platforms on users' study efficiency and develop cognitive indicators to evaluate users' study efficiency on mobile learning platforms.

Layout style was the only independent factor that was investigated. A between-group experimental design was employed. Eye movement data were recorded during the experiment, following which participants were asked to complete an after-scenario questionnaire. This study evaluated the usability of the proposed new design using both subjective and objective data. The computer system usability questionnaire V3 (CSUQ) was used to measure subjective data. For the eye-tracking measure, gaze entropy, the proportion of fixation count and duration of each AOI were calculated. Gaze entropy reflects the complexity of information organization. Fixation counts and AOI duration represent the difficulty of information processing and attention distribution, respectively during the task.

The results indicated that interface layout presents significant effects on user's learning efficiency, usability and cognitive load. Sequential layout improved efficiency and satisfaction among participants and reduced information complexity. The results provided useful insights for designers whose goal is to improve user's learning efficiency under mobile learning scheme.

This study investigated the effects of interface layout on usability, user performance and cognitive load using subjective ratings and eye-tracking technology. Gaze entropy was used to measure the complexity of information organized by the interface design. Fixation count and duration proportion were used to identify the difficulty of information processing and distinguish users' distribution of cognitive resources. The results indicated that a vertical layout panel design was more efficient than a horizontal layout panel design. The design implications of the eye tracking indicators and research results were then summarized. This study is expected to encourage designers to optimize their design proposals using eye tracking testing.

The purpose of this paper is to provide an analytical method of jet flow injection direction and to determine the influence of oil nozzle structure parameters on oil injection direction, thus providing the design method of oil nozzle structure parameters.

A model of oil injection loss is established to analyze the influence of oil nozzle structure parameters on oil injection direction. The computational fluid dynamics method is used to simulate the process of the deviation of jet flow injection direction. The deviation of jet flow injection direction with different oil nozzle structure parameters is calculated and their variations are obtained. Moreover, the deviation of jet flow injection direction with different oil nozzle structure parameters is tested to verify the analysis results.

Results indicate that radial velocity caused the deflection of the oil injection direction. The deviation of jet flow increased as the nozzle slenderness ratio decreased. The design method of the nozzle slenderness ratio (greater than five) is proposed to avoid the deviation of injection direction, and it is necessary to consider the matching between the nozzle slenderness ratio and pipeline pressure. The computational results coincide well with the experimental results.

The research presented here analyzed the influence of oil nozzle structure parameters on oil injection direction via a numerical analysis method. It also leads to a design reference guideline that could be used in jet lubrication, thus controlling the direction of the injection jet accurately.

This study examines the effect of political networking capability (PNC) and strategic capability on exploratory innovation/exploitative innovation through the mediation of absorptive capability (AC).

Using empirical survey data collected from 153 traditional manufacturing firms (TMFs) in China, the authors apply partial least squares structural equation modeling (PLS-SEM) combined with mediation analyses to test hypotheses.

PNC has a higher impact on exploratory innovation than exploitative innovation through AC. The authors thus provide novel empirical insights into independent variables of firms' ambidextrous innovation and their implementation mechanisms.

The authors highlight a unique situation of China and contribute to the literature on PNC and AC. The findings demonstrate that AC plays an important role in configuring government-obtained external resources into new products, thus influencing ambidextrous innovation strategic decisions.

TMFs' executives should enhance PNC to obtain more resources to conduct exploratory and exploitative innovation. Government officials and policymakers should strengthen the supervision of TMFs' innovation activities and adopt effective measures to ensure that TMFs could conduct more exploratory innovation as governments expected.

This study provides new insights by bridging research gaps in the literature and advances the insights of how TMFs' PNC/strategic capability directly and indirectly fosters exploratory and exploitative innovation via the mediating role of AC in China.

Mg-Al powder mixture was used to manufacture Mg-Al alloy by laser powder bed fusion (LPBF) process. This study aims to investigate the influence of initial Al content and processing parameters on the formability, microstructure and consequent mechanical properties of the laser powder bed fused (LPBFed) component.

In this study, Al powder with different weight ratio ranged from 3 to 9 per cent was mixed with pure Mg powder, and the powder mixture was processed using different LPBF parameters. Microstructure and compressive properties of the LPBFed components were examined.

It was found that the presence of Al significantly modified the microstructure and improved the mechanical properties of the LPBFed components. Higher volume of ß-Al12Mg17 precipitates was produced at higher initial Al content and higher laser energy density. For this reason, the a-Mg was significantly refined and the compressive strength was improved. The highest yield compressive strength achieved was 279 MPa when using Mg-9 Wt. % Al mixture.

This work demonstrates that LPBF of Mg-Al powder mixture was a viable way to additively manufacture Mg-Al alloy. Both Al content and processing parameters can be modified to control the microstructure and mechanical properties of the LPBFed components.

During the 3D printing process, the model needs to add a support structure to ensure structural stability. Excessive support structure reduces printing efficiency and results in material cost. A flexible support platform for 3 D printing has been designed. It can form an external support structure to replace the original support structure. This paper aims to study the influence of a model’s build orientation on properties when the model is printed on the platform, aiming to provide users with suitable solutions.

A fitness function for estimating the support structure with a support length is constructed. The particle swarm optimization (PSO) algorithm is modified and applied to find the build orientation that minimizes the support structure. However, when the model is printed on the platform, the build orientation of the minimum support structure enhances the complexity of the working path, resulting in an increase of printing time, which needs to be avoided. This paper applies a multi-objective particle swarm optimization (MOPSO) algorithm to minimize the support structure while minimizing printing time. The Pareto solution is obtained by the algorithm.

It is found that the model that has the cantilever structure can reduce more support structure after optimization on the platform, when there is surface quality requirement. When there is no limit, the modified algorithm can minimize the support structure of each model. Considering support structure and printing time, the MOPSO algorithm can easily get optimization results to guide the practical work.

This paper optimizes the model’s build orientation on the flexible support platform by PSO, thereby reducing material cost and improving work efficiency.

The purpose of this paper is to identify the design elements of environmental features that affect consumer experience in shopping malls and develop a comprehensive understanding of the relationship between architectural design and consumer experience.

Through the systematic literature review, 13 design elements were obtained and then verified through interviews of 30 professional designers. The obtained elements were made into a questionnaire to collect data across China from 1,016 consumers of different groups. Data were analyzed using cluster analysis, principal component analysis and difference analysis.

The results show that design elements that influence consumer experience in shopping malls are a four-dimensional construct: visual atmosphere, physical environment comfort, space structure and business planning, among which space structure and business planning play a larger role in the consumer experience. In addition, the perception differences of consumers for those elements are significant due to the individual differences.

This paper comprehensively investigates the architectural design elements affecting consumer experience in the Chinese mall context. Moreover, it provides unique insights about the relationship between architectural design and consumer experience by exploring the categories, weights and perception differences of those elements.

From the perspective of social networks and knowledge networks, this study aims to empirically examine an updated four-dimension networking capability (NC) construct and test the relationships between it and innovation strategies through knowledge application activities in the context of Chinese manufacturing firms.

Data analysis is conducted on a quantitative survey of 219 manufacturing firms in China with a mixed method of partial least squares structural equation modeling and fuzzy-set qualitative comparative analysis.

The results indicate that knowledge assimilation application (KAA) and knowledge transformation application (KTA) fully mediate the relationships between NC and ambidextrous innovation strategies. KAA has a stronger association with exploitative innovation (EL) than with exploratory innovation (ER), and KTA has a stronger association with ER than with EL.

The authors develop the conceptualization of NC and examine its role in knowledge application activities within a firm. Further, the authors adopt an alternative perspective to highlight the importance of KAA and KTA in mediating the relationships between NC and exploratory and exploitative innovation strategies.

The findings indicate that firms should build NC based on their knowledge requirements and knowledge network structure. Additionally, managers should possess in-depth insights regarding an effective knowledge application toward different types of external knowledge from partners. More specific, firms are more likely to conduct KAA for a high degree of knowledge relatedness, while for a low degree of knowledge relatedness, firms are more likely to conduct KTA.

The authors provide a novel alternative insight into knowledge application activities. From the perspective of knowledge networks, the authors argue that there are two distinct and parallel activities (i.e. KAA and KTA). The authors empirically examined the mediating roles of KAA and KTA in the NC–ambidextrous innovation strategies relationships as well as enriched the literature on their relationships.

The purpose of this paper is to establish a stiffness model of fixed joint considering self-affinity and elastoplasticity of asperities.

The proposed model considers that asperities of different scales are interrelated rather than independent. For elastoplastic contact, a spring-damper model and an elastic deformation ratio function were proposed to calculate the contact stiffness of asperities.

A revised fractal asperity model was proposed to calculate the contact stiffness of fixed joint, the impacts of the fractal dimension, the fractal roughness parameter and the Meyer index on the contact stiffness were discussed, and the present experimental results and the Jiang’s experimental results showed that the stiffness can be well predicted by proposed model.

The contradiction between the Majumdar and Bhushan model and the Morag and Etsion model can be well explained by considering the interaction among asperities of different scales. For elastoplastic contact, elastic deformation ratio should be considered, and the stiffness of asperities increases first and then decreases with the increasing of interference.

This paper aims to present error compensation based on surface reconstruction to improve the positioning accuracy of industrial robots.

In previous research, it has been proved that the positioning error of industrial robots is continuous on the two-dimensional manifold of six-joint space. The point cloud generated by positioning error data can be used to fit the continuous surfaces, which makes it possible to apply surface reconstruction on error compensation. The moving least-squares interpolation and the B-spline method are used for the error surface reconstruction.

The results of experiments and simulations validate the effectiveness of error compensation by the moving least-squares interpolation and the B-spline method.

The proposed methods can control the average of compensated positioning error within 0.2 mm, which meets the requirement of a tolerance (±0.5 mm) for fastener hole drilling in aircraft assembly.

The error surface reconstruction based on the B-spline method has great superiority because fewer sample points are needed to use this method than others while keeping the compensation accuracy at the same level. The control points of the B-spline error surface can be adjusted with measured data, which can be applied for the error prediction in any temperature field.

This paper aims to reveal the mechanism of air barrier effect in jet lubrication and to figure out the influence of gear parameters and conditions on air barrier, thus providing guidance to the design of jet lubrication in ultra-high speed gear cooling system.

The computational fluid dynamics method is used to calculate the flow and pressure of ultra-high speed gears. The flow and pressure distributions are obtained under different gear parameters and working conditions, so their variations are obtained. A multiphase flow model is established to simulate the flow regime of oil jet to ultra-high speed gears. Simple experiments are carried out to observe the air barrier effect of high-speed gears.

Air barrier effect exists in the jet lubrication of ultra-high speed spur gears, which could prevent oil jet to reach on the gear surfaces. The results show that the generated pressure has positive relations with gear speed, module and width; however, as the increasing of gear width, their marginal contribution to pressure is decreasing. The computational results coincide well with the experimental results.

The research presented here proposed the air barrier effect of ultra-high speed gears for the first time. It also leads to a design reference guideline that could be used in jet lubrication of ultra-high speed gears, thus preventing lubrication and cooling failures.