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The objective of this paper is to survey the recent developments in economic theories of buyer power and using the theories as a guide to discuss how antitrust cases involving buyer power can be analysed. An important conclusion that emerges from this survey is that the competition effects of buyer power are quite different depending on whether it is monopsony power against powerless suppliers or countervailing buyer power against large suppliers with market power. A proposed framework of antitrust analysis is presented, and issues related to market definitions and determination of buyer power are discussed.

Combining technology acceptance model and the theory of planned behavior, this study aims to analyze influencing factors on intention of sharing heritage tourism experience in social media from technological, psychological and experience perspectives. The moderating effects of age and gender are also tested.

This study applies a quantitative method using online questionnaires. A total number of 323 questionnaires are collected. The data are analyzed using partial least squares-structural equation modeling to assess measurement and structural models and multi-group analysis to compare differences among age and gender groups.

The results of this study indicate that subjective norm, perceived behavioral control and tourism experience significantly and positively influence the intention of sharing heritage tourism experience in social media, while the effects of perceived usefulness, perceived ease of use and attitude are non-significant. Results reveal the differences in antecedents of sharing heritage tourism experience in social media between males and females and between younger and older tourists.

Developing a model integrating technology acceptance model and theory of planned behavior, this paper analyzes the intention of sharing heritage tourism experience in social media through technological, psychological and tourism experience perspectives. Besides, heterogeneous comparisons between younger and older tourists and between males and females offer significant academic and practical insights.

本研究结合技术接受模型（TAM）和计划行为理论（TPB）, 旨在从技术、心理和体验的角度分析在社交媒体上分享文化遗产旅游体验意愿的影响因素, 同时还测试了年龄和性别的调节效应。

本研究采用定量方法, 使用在线问卷进行调查。共收集到323份问卷。使用PLS-SEM来评估测量和结构模型, 使用多组分析（MGA）来比较不同年龄和性别组之间的差异。

结果表明, 主观规范、感知行为控制和旅游体验对在社交媒体上分享文化遗产旅游体验的意愿有显著的正向影响, 而感知有用性、感知易用性和态度的影响是不显著的。结果揭示了男性和女性以及年轻游客和老年游客之间在社交媒体上分享文化遗产旅游体验前因的差异。

本文开发了一个整合了TAM和TPB的模型, 通过技术、心理和旅游体验的视角分析了在社交媒体上分享文化遗产旅游体验的意愿。此外, 对年轻游客和老年游客以及男性和女性之间的异质比较提供了重要的学术和实践见解。

Constructing porous wind barriers is one of the most effective approaches to increase the running safety of trains on viaducts in crosswinds. This paper aims to further improve the wind-sheltering performance of the porous wind barriers.

Improved delayed detached eddy simulations based on the k-ω turbulence model were carried out, and the results were validated with wind tunnel tests. The effects of the hole diameter on the flow characteristics and wind-sheltering performance were studied by comparing the wind barriers with the porosity of 21.6% and the hole diameters of 60 mm–360 mm. The flow characteristics above the windward and leeward tracks were analyzed, and the wind-sheltering performance of the wind barriers was assessed using the wind speed reduction coefficients.

The hole diameters affected the jet behind the wind barriers and the recirculation region above the tracks. Below the top of the wind barriers, the time-averaged velocity first decreased and then increased with the increase in the hole diameter. The wind barrier with the hole diameter of 120 mm had the best wind-sheltering performance for the windward track, but such barrier might lead to overprotection on the leeward track. The wind-sheltering performance of the wind barriers with the hole diameters of 240 mm and 360 mm was significantly degraded, especially above the windward track.

The effects of the hole diameters on the wake and wind-sheltering performance of the wind barriers were studied, by which the theoretical basis is provided for a better design of the porous wind barrier.

The paper examines the effects of individual differences on the key motivational factors affecting Chinese study abroad students.

The current study adopts a quantitative survey approach. Students are recruited through the largest online survey provider in China. Using 335 completed questionnaires and factor analysis, the key factors influencing Chinese students are identified. Subsequently, regressions are employed to analyse the impact of age, gender, socio-economic status, previous study or travel abroad experience, degree level and location on factor scores.

This research sheds new light on the decision-making process of Chinese study abroad students. It is found that Chinese students are influenced by three key factors, social, cultural and economic environment, non-personal and personal recommendations. The results reveal that male students from the lowest socio-economic group rely on non-personal information to decide destination where they can significantly upgrade their socio-economic status. Personal recommendations are used by young persons aged between 18 and 24 and those without previous overseas travel or study experience.

Although prior studies explore the motivations of Chinese study abroad students, very few focus on a large sample of students both in China and abroad and identify key factors using the statistical tool factor analysis. No research has been carried out to understand the impact of personal characteristics such as age, gender, prior study or travel abroad experience, degree level and location on significant factor scores. Such analysis is crucial for the financial stability of the international higher education market, particularly during the current COVID-19 crisis.

This paper aims to adapt and computerize the Trail Making Test (TMT) to support long-term self-assessment of cognitive abilities.

The authors propose a divide-and-combine (DAC) approach for generating different instances of TMT that can be used in repeated assessments with nearly no discernible practice effects. In the DAC approach, partial trails are generated separately in different layers and then combined to form a complete TMT trail.

The proposed approach was implemented in a computerized test application called iTMT. A pilot study was conducted to evaluate iTMT. The results show that the instances of TMT generated by the DAC approach had an adequate level of difficulty. iTMT also achieved a stronger construct validity, higher test–retest reliability and significantly reduced practice effects than existing computerized tests.

The preliminary results suggest that iTMT is suitable for long-term monitoring of cognitive abilities. By supporting self-assessment, iTMT also can help to crowdsource the assessment processes, which need to be administered by healthcare professionals conventionally, to the patients themselves.

This study aims to explore the 3 D separated flow fields and heat transfer characteristics at the end wall of a serpentine channel with various turn clearances using topological analysis and critical points principles of three-dimensional vortex flow.

This aims to explore the 3 D separated flow fields and heat transfer characteristics at the end wall of a serpentine channel with various turn clearances using topological analysis as well as critical points principles of three-dimensional vortex flow.

The endwall heat transfer in the narrow spacing passage is significantly stronger than that in a wide spacing channel. As the gap clearance is kept at 0.87 times of the hydraulic diameter, the endwall heat transfer and thermal performance can be accordingly enhanced with low pressure drops, which is because a relatively strong concentrated impingement flow for the medium gap clearance helps to restrain the downstream fluid flow and enhance the shear effect of the secondary flow.

The numerical results can be applied in designing sharp turn of serpentine channel in heat exchangers, heat sinks, piping system, solar receiver and gas turbine blades.

The evolution mechanism of the vortices in the turning region under different gap clearance was analyzed, and thermal enhancement characteristics were predicted innovatively using topological analysis method.

This study aims to propose a novel method based on model learning with sparsity inducing norms for estimating dynamic gravity terms of the serial manipulators. This method is realized by operating the robot, acquiring data and filtering the features in signal acquisition to adapt to the dynamic gravity parameters.

The core principle of the method is to analyze the dictionary composition of the basis function of the model based on the dynamic equation and the Jacobian matrix of an arm. According to the structure of the basis function and the sparsity of the features, combined with joint-angle and driving-torque data acquisition, the effective features of dynamic gravity parameters are screened out using L1-norm optimization and learning algorithms.

The theoretical analysis revealed that training data obtained based on joint angles and driving torques could rapidly update dynamic gravity parameters. The simulation experiment was carried out by using the publicly available robot model and compared with the previous disassembly method to evaluate the feasibility and performance. The real 7-degree of freedom (DOF) industrial manipulator was used to further discuss the effects of the feature selection. The results show that this estimation method can be fully operational and efficient in industrial applications.

This approach is applicable to most serial robots with multi-DOF and the dynamic gravity parameters of the robot are estimated through learning and optimization. The method does not require prior knowledge of the robot arm structure and only requires joint-angle and driving-torque data acquisition under low-speed motion. Furthermore, as it is a data-driven-based method, it can be applied to gravity parameters updating.

Different from previous general robot dynamic modelling methods, the sparsity of the analytical form of dynamic equations was exploited and model learning was formulated as a convex optimization problem to achieve effective gravity parameters screening. The novelty of this estimation approach is that the method does not only require any prior knowledge but also does not require a specifically designed trajectory. Thus, this method can avoid the laborious work of parameter calibration and the induced modelling errors. By using a data-driven learning approach, the new parameter updating process can be completed conveniently when the robot carries additional mass or the end-effector changes for different tasks.

Today’s software engineers often work in teams to develop complex software systems. Therefore, successful software engineering in practice require team members to possess not only sound programming skills such as analysis, design, coding and testing but also soft skills such as communication, collaboration and self-management. However, existing examination-based assessments are often inadequate for quantifying students’ soft skill development. The purpose of this paper is to explore alternative ways for assessing software engineering students’ skills through a data-driven approach.

In this paper, the exploratory data analysis approach is adopted. Leveraging the proposed online agile project management tool – Human-centred Agile Software Engineering (HASE), a study was conducted involving 21 Scrum teams consisting of over 100 undergraduate software engineering students in multi-week coursework projects in 2014.

During this study, students performed close to 170,000 software engineering activities logged by HASE. By analysing the collected activity trajectory data set, the authors demonstrate the potential for this new research direction to enable software engineering educators to have a quantifiable way of understanding their students’ skill development, and take a proactive approach in helping them improve their programming and soft skills.

To the best of the authors’ knowledge, there has yet to be published previous studies using software engineering activity data to assess software engineers’ skills.

The purpose of this study is to investigate the effects of film holes’ arrangements and jet Reynolds number on flow structure and heat transfer characteristics of jet impingement conjugated with film cooling in a semicylinder double wall channel.

Numerical simulations are used in this research. Streamlines on different sections, skin-friction lines, velocity, wall shear stress and turbulent kinetic energy contours near the concave target wall and vortices in the double channel are presented. Local Nusselt number contours and surface averaged Nusselt numbers are also obtained. Topology analysis is applied to further understand the fluid flow and is used in analyzing the heat transfer characteristics.

It is found that the arrangement of side films positioned far from the center jets helps to enhance the flow disturbance and heat transfer behind the film holes. The heat transfer uniformity for the case of 55° films arrangement angle is most improved and the thermal performance is the highest in this study.

The film holes’ arrangements effects on fluid flow and heat transfer in an impingement cooled concave channel are conducted. The flow structures in the channel and flow characteristics near target by topology pictures are first obtained for the confined film cooled impingement cases. The heat transfer distributions are analyzed with the flow characteristics. The highest heat transfer uniformity and thermal performance situation is obtained in present work.