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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.

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 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.

During service period, due to the overload or other non-load factors, cracks of the pre-stressed concrete beam are seriously affecting the safety of the bridge structure. The purpose of this paper is to quickly realize the bearing capacity and the loss of the section stiffness through fracture characteristics and make correct judgments.

Through the flexural failure test of two test beams: collecting data of fracture characteristics and section stiffness loss value. According to the fracture characteristic data, the flexural stiffness of the section is obtained by the nonlinear calculation method, and the results are verified by test data. Data regression method is used to establish the section flexural stiffness loss ratio calculation formula, nominal tensile strain at the bottom edge of the cross-section used as a variable factor, and the accuracy of this formula is verified by comparing the flexural failure test results of pre-stressed hollow plates.

The loss of the flexural stiffness of section shows the decrease trend of first-fast-then-slow and the structural stiffness is sensitive to the initial cracking of beam. The calculation formula on the loss ratio of the flexural stiffness of section established with the nominal tensile stress at the bottom edge of beam as a variable is accurate and feasible, it realizes the possibility of assessing the stiffness loss of pre-stressed concrete structure by adopting the statistic parameters on crack characteristics.

A method for quickly determine the stiffness loss of structures by using fracture characteristics is established, and using this method, engineers can quickly determine whether a bridge is a dangerous bridge, without loading test. So, this method not only ensures the safety of human life, but also saves money.

During service period, due to the overload or other non-load factors, diagonal cracks of the pre-stressed concrete beam are seriously affecting the safety of the bridge structure. The purpose of this paper is to quickly realize the shear bearing capacity and shear stiffness through maximum width of the diagonal cracks and make correct judgments.

Through the shear failure test of four test beams, collecting data of diagonal cracks and shear stiffness loss value. According to the deformation curve of the shear stiffness, and combined with the calculation formula of the maximum width of diagonal cracks, the formula for calculating the effective shear stiffness based on the maximum width of diagonal cracks is deduced, then the results are verified by test data. Data regression method is used to establish the effective shear stiffness loss ratio calculation formula, the maximum width of diagonal cracks used as a variable factor, and the accuracy of this formula is verified by comparing the shear failure test results of pre-stressed hollow plates.

With the increase in width of the diagonal crack, the loss rate of shear stiffness of the concrete beams is initially fast and then becomes slow. The calculation formulae for shear stiffness based on the maximum width of the diagonal cracks were deduced, and the feasibility and accuracy of the formulae were verified by analysis and calculation of shear test data.

A method for quickly determine the shear stiffness loss of structures by using maximum width of the diagonal cracks is established, and using this method, engineers can quickly determine effective shear stiffness loss ratio, without complex calculations. So this method not only ensures the safety of human life, but also saves money.

This paper aims to review the literature on mobile information services. It considers only peer-reviewed papers published in English between 2004 and 2014.

The method of systematic review was adopted to collect and analyse the relevant literature. The searches were conducted during the last week of July 2014 on different databases, and in total, 76 papers were considered after applying inclusion and exclusion criteria.

Seven themes emerged: “introducing mobile libraries”, “reporting on current trends”, “exploring users’ perceptions of libraries’ mobile services”, “presenting libraries’ mobile services”, “presenting mobile technology use in libraries”, “reporting case studies” and “reporting on evaluation of libraries’ mobile services”. It is evident that research on mobile libraries is very recent and focuses mainly on raising the Library and Information Science profession’s awareness of providing mobile information services.

This literature review focused only on peer-reviewed papers published between 2004 and 2014 in English.

This paper summarises and critically presents the relevant literature on libraries offering mobile information services. It informs libraries and librarians’ understanding of recent developments in mobile technology for the successful provision of information services.

This paper aims to study the attitude control problem with mutating orbital rate and actuator fading.

To avoid malicious physical attacks and hide itself, the spacecraft may irregularly switch its orbit altitude within a specific range, which will bring about variations in orbital rate, thereby causing mutations in the attitude dynamics model. The actuator faults will also cause changes in system dynamics. Both factors affect the control performance. First, this paper determines the potential switching orbits. Then under different conditions, design controllers that can accommodate actuator faults according to the statistical law of actuator fading.

This paper, to the best of the authors’ knowledge, for the first time, introduces the Markovian jump framework to model the possible unexpected mutating of orbital rate and actuator fading of spacecraft and then designs a novel control policy to solve the attitude control problem.

This paper also provides the algorithm design processes in detail. A comparative numerical simulation is given to verify the effectiveness of the proposed algorithm.

This is an early solution for spacecraft attitude control with dynamics model mutations.

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.

The operation safety of the high-speed railway has been widely concerned. Due to the joint influence of the environment, equipment, personnel and other factors, accidents are inevitable in the operation process. However, few studies focused on identifying contributing factors affecting the severity of high-speed railway accidents because of the difficulty in obtaining field data. This study aims to investigate the impact factors affecting the severity of the general high-speed railway.

A total of 14 potential factors were examined from 475 data. The severity level is categorized into four levels by delay time and the number of subsequent trains that are affected by the accident. The partial proportional odds model was constructed to relax the constraint of the parallel line assumption.

The results show that 10 factors are found to significantly affect accident severity. Moreover, the factors including automation train protection (ATP) system fault, platform screen door and train door fault, traction converter fault and railway clearance intrusion by objects have an effect on reducing the severity level. On the contrary, the accidents caused by objects hanging on the catenary, pantograph fault, passenger misconducting or sudden illness, personnel intrusion of railway clearance, driving on heavy rain or snow and train collision against objects tend to be more severe.

The research results are very useful for mitigating the consequences of high-speed rail accidents.