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The purpose of this paper is to propose a new joint friction model, which can accurately model the real friction, especially in cases with sudden changes in the motion direction. The identification and sensor-less control algorithm are investigated to verify the validity of this model.

The proposed friction model is nonlinear and it considers the angular displacement and angular velocity of the joint as a secondary compensation for identification. In the present study, the authors design a pipeline – including a manually designed excitation trajectory, a weighted least squares algorithm for identifying the dynamic parameters and a hand guiding controller for the arm’s direct teaching.

Compared with the conventional joint friction model, the proposed method can effectively predict friction factors during the dynamic motion of the arm. Then friction parameters are quantitatively obtained and compared with the proposed friction model and the conventional friction model indirectly. It is found that the average root mean square error of predicted six joints in the proposed method decreases by more than 54%. The arm’s force control with the full torque using the estimated dynamic parameters is qualitatively studied. It is concluded that a light-weight industrial robot can be dragged smoothly by the hand guiding.

In the present study, a systematic pipeline is proposed for identifying and controlling an industrial arm. The whole procedure has been verified in a commercial six DOF industrial arm. Based on the conducted experiment, it is found that the proposed approach is more accurate in comparison with conventional methods. A hand-guiding demo also illustrates that the proposed approach can provide the industrial arm with the full torque compensation. This essential functionality is widely required in many industrial arms such as kinaesthetic teaching.

First, a new friction model is proposed. Based on this model, identifying the dynamic parameter is carried out to obtain a set of model parameters of an industrial arm. Finally, a smooth hand guiding control is demonstrated based on the proposed dynamic model.

This paper aims to develop a theoretical method to analyze the rotation accuracy of rotating machinery with multi-support structures. The method effectively considers the geometric errors and assembly deformation of parts.

A method composed of matrix and FEA methods is proposed to do the analysis. The deviation propagation analysis results and external loads are set as boundary conditions of the model which is built with Timoshenko beam elements to calculate the spatial pose of the rotor. The calculation is performed repeatedly as the rotation angle increased to get the rotation trajectories of concerned nodes, and further evaluation is done to get the rotation accuracy. Additionally, to get more reliable results, the bearing motion errors and stiffness are analyzed by a static model considering manufacturing errors of parts.

The feasibility of the proposed method is verified through a case study of a high-precision spindle. The method reasonably predicts the rotation accuracy of the spindle.

For rotating machinery with multi-support structures, the paper proposes a modeling method to predict the rotation accuracy, simultaneously considering geometric errors and assembly deformation of parts. This would improve the accuracy of tolerance analysis.

This paper aims to propose a hybrid force/position control algorithm based on the stiffness estimation of the unknown environment. A frequency-division control scheme is developed to improve the applicability and reliability of the robot in welding, polishing and assembly.

The stiffness estimation algorithm with time-varying forgetting factors is used to improve the speed and accuracy of the unknown environmental estimation. The sensor force control and robot position control are adopted in different frequencies to improve system stability and communication compatibility. In the low frequency of sensor force control, the Kalman state observer is used to estimate the robot’s joints information, whereas the polynomial interpolation is used to ensure the smoothness of the high frequency of robot position control.

Accurate force control, as well as the system stability, is attained by using this control algorithm.

The entire algorithm is applied to a six-degrees-of-freedom industrial robot, and experiments are performed to confirm its applicability.

The frequency-division control strategy guarantees the control stability and improves the smoothness of the robot movement.

The purpose of this paper is to reveal the knowledge evolution process, research hotspots and future trends in the accessible tourism research literature from 2008 to 2020.

A total of 213 articles on accessible tourism were selected from the core collection database of Web of Science (WoS) and analyzed using CiteSpace.

Over the 13-year period between 2008 and 2020, an increasing number of studies have been published concerning accessible tourism, but the overall base is still small. The research content mainly includes six modules. Among institutions, the University of Technology Sydney has published the largest number of papers. Cooperation among countries involves the USA, the United Kingdom, Australia, Portugal and China. Tourism Management is the leading journal for disseminating research on accessible tourism. Definition of “Accessible tourism” and the different scope of this phenomenon are re-discussed. In recent years, “experience” and “participation” have become the “new favorites” in accessible tourism research, which could reveal insights into future research directions.

The sampling frame was defined in terms of the WoS database and even though this is an important database for global academic information, in the big data era, the authors may have to integrate information from multiple sources to comprehensively reveal and understand knowledge maps. Second, because of the operational constraints of the CiteSpace software, the authors only selected outputs published in peer-reviewed journals, excluding other published works, such as books and conference papers. Finally, because of the language restrictions of the authors, this research is limited to journals published in the English language.

Practically, the results of this study made a conclusion of accessible tourism research so that the researchers can easily know what has currently been done and what future research can do. Tourism managers can also understand the demands and the constraints of tourism for the people who have barriers to travel. They can supply more specific products for the accessible tourism and further promote the construction of barrier-free travel environments.

This paper unifies the literature on senior tourism and people with disabilities tourism, and uses CiteSpace to construct data and network visualizations, including a burst and dynamic analysis for the period covered by the sample. Furthermore, this paper proposed a more diversified accessible tourism.

无障碍旅游：文献计量学研究综述 (2008-2020)

此篇论文目的是通过对2008年到2020年间无障碍旅游研究文献进行科学计量和可视化分析, 展示该领域的知识演变进程、研究热点和未来趋势。

从Web of Science核心合集数据库中经过多次筛选, 挑选出213篇文章, 并利用CiteSpace进行分析。

13年来无障碍旅游的研究文献数量总体呈上升趋势, 但总体基数仍然不大, 研究内容主要包含六个模块。机构中悉尼科技大学的发文量最多。国家间的合作以美国、英国、澳大利亚、葡萄牙和中国为基础。主要发行期刊是Tourism Management。本文还对无障碍旅游的定义和内涵重新进行了思考和讨论。近年来“体验”和“参与”成为了无障碍旅游研究中的“新宠”, 揭示出未来的研究方向。

此篇论文将老年旅游和残障旅游统一起来, 并利用CiteSpace做出清晰的数据和网络展示, 包含了过去13年的突发性和动态性分析。并且, 本文提出了更为广泛和多元的无障碍旅游。

无障碍旅游; 残障旅游; 老年旅游; 文献综述; CiteSpace

文章类型： 研究综述

Turismo accesible: una revisión bibliométrica (2008–2020)

El objetivo de este trabajo es revelar el proceso evolutivo del conocimiento, los puntos críticos de la investigación y las futuras tendencias de la literatura de investigación del turismo accesible del 2008 a 2020.

De la base de datos central de la red científica, se seleccionaron 213 artículos sobre turismo accesible y se analizaron utilizando citespace.

En los 13 años transcurridos entre 2008 y 2020 se han realizado cada vez más publicaciones relacionadas con el turismo accesible, pero la base general sigue siendo pequeña. Las investigaciones incluyen principalmente seis módulos. Entre los institutos, la Universidad Tecnológica de Sídney a publicado el mayor número de investigaciones. La cooperación entre los países incluye a los Estados Unidos, Reino Unido, Australia, Portugal y China. La “Tourism Management” es la principal revista de investigación sobre el turismo accesible. Este artículo rediscute la definición de “turismo accesible” y el diferente alcance de este fenómeno. En los últimos años, la “experiencia” y la “participación” se han convertido en el “nuevo favorito” de las investigaciones sobre el turismo accesible, lo que podría revelar perspectivas con relación a la dirección de futuras investigaciones.

Esta investigación combina la literatura relacionada con el turismo adulto mayor y personas con discapacidad, utiliza citespace para construir los datos y la visualización de la red, incluyendo un análisis dinámico y de ráfagas para el período cubierto por la muestra. Además, este documento propone un turismo accesible más diversificado.

Turismo accesible, Personas con discapacidad, Adulto mayor, Bibliometría, CiteSpace

RevisiÓn de la literatura

The purpose of this paper is to present a numerical model to investigate the dynamic behavior and force coefficients of a compact squeeze film damper with dual film clearances adjusted by an elastic ring, known as elastic ring squeeze film damper (ERSFD).

The governing equations of ERSFD as well as the boundary conditions are obtained based on Reynolds equation. A simplified Greenwood–Williamson model is implemented to investigate the contact behavior between the elastic ring and the journal. The interactions between the films and the elastic ring are achieved by block iterative method.

The radial deformation as well as velocity of the elastic ring are captured to illustrate the pressure profiles of the inner and outer films. High-order frequency components related to the number of the boss N are observed on the frequency spectrum of the film force. The force coefficients of the ERSFD are constant for a wider range of non-dimensional whirling radius ε compared with conventional squeeze film damper.

The force coefficients of the ERSFD are obtained by assuming that the journal center moves in a circular centered orbit. High-order frequency components related to the number of bosses N are observed. These findings may provide helpful materials for the application of the ERSFD.

Overqualification is a growing concern for employers in many countries. The practice of mismatching employees and positions inevitably leads to an increase in organizational training and management costs. This study can not only further enrich the theoretical achievements in the field of human resource management, but can also provide a reference for enterprise managers on how to effectively stimulate employees' innovative behaviour.

503 questionnaire responses were analysed using SPSS 24.0 and Mplus 8.0.

It was concluded that, (1) perceived overqualification is negatively related to employees' innovation behaviour (β = −0.32, p < 0.001); (2) psychological contract breach and psychological distance partially mediate the relationship between perceived overqualification and employees' innovation behaviour. Among them, the mediating effect of psychological contract breach was −0.14 (p < 0.01), and that of psychological distance was −0.12 (p < 0.001); the chain-mediating effect of psychological contract breach and psychological distance was −0.09 (p < 0.01); (3) employment relationship atmosphere played a moderating role in the relationship between perceived overqualification and employees' innovation behaviour (β = 0.04, p < 0.01).

This study verifies the negative impact of perceived overqualification on employee innovation behaviour and reveals the mediating role of psychological factors between the two. It also discusses the moderating effect of employment relationship climate on the relationship between perceived overqualification and employees' innovation behaviour.

The physiological and psychological issues that limit people with vision impairment make it difficult for them to participate in tourism activities and enjoy the various benefits of tourism. This study aims to construct a theoretical model of the tourism-influencing factors that can lead to problems for people with vision impairment to meet their travel desires and improve their enjoyment of life.

This study adopted a mixed-methods approach. A theoretical model of the tourism-influencing factors for people with vision impairment was constructed based on grounded theoretical analysis of interviews and was then tested in a quantitative survey.

In the first stage, a new theoretical model of the tourism-influencing factors for people with vision impairment was conducted. In the second stage, five research hypotheses arising from the theoretical model were tested in a quantitative survey. The results show that internal psychological perception, perceived behavioural control and perceived social intention have a significant positive impact on the tourism intention behaviour of people with vision impairment. However, subjective norms do not significantly influence the tourism behaviour intention of people with vision impairment.

The right to tourism should be available to disabled as well as to able-bodied people. Few tourism research studies have focused on people with vision impairment, and the influencing factors on the behaviour of people with vision impairment have not received due attention. This study extends the theoretical model of the theory of planned behaviour and provides a new perspective for understanding the travel behaviour intention of people with vision impairment.

视障者受生理和心理问题的限制, 较难参与旅游活动并享受旅游带来的各种好处。本研究旨在构建出视障者旅游行为影响因素理论模型, 以满足视障群体的旅游需求, 并提高他们的生活幸福感。

本研究采用混合研究方法。以访谈为基础进行扎根理论分析, 构建出视障者旅游行为影响因素的理论模型, 并通过定量研究验证模型。

第一阶段, 构建了视障者旅游行为影响因素的新理论模型。第二阶段, 根据构建出的理论模型提出五个研究假设, 并通过定量研究进行验证。研究结果显示内在心理感知、知觉行为控制和社会支持感知对视障者旅游行为意向存在显著正向影响, 而主观规范对视障者旅游行为意向的影响不显著。

视障者同健全者拥有平等的旅游权利。但旅游研究中针对视障群体的研究很少, 对视障者旅游行为影响因素的研究更未得到应有的重视。本研究拓展了计划行为理论模型, 为理解视障者旅游行为意向提供了新的视角。

La limitación de los problemas físicos y psicológicos de las personas con discapacidad visual, dificulta su participación en actividades turísticas y el disfrute de los beneficios del turismo. El objetivo de este estudio es construir un modelo teórico de los factores que influyen en el turismo y que puedan causar problemas a las personas con discapacidad visual para satisfacer sus deseos turísticos y mejorar su disfrute de la vida.

En este estudio se utilizó un método mixto. Sobre la base del análisis de la teoría de la raíz de la entrevista, se construye el modelo teórico de los factores que influyen en el turismo de las personas con discapacidad visual.

En la primera etapa, se establece un nuevo modelo teórico sobre los factores que influyen en el turismo de las personas con discapacidad visual. En la segunda etapa, se investigan cuantitativamente las cinco hipótesis de investigación presentadas por el modelo teórico. Los resultados mostraron que la percepción psicológica interna, el control del comportamiento percibido y la intención social percibida tenían un efecto positivo significativo en el comportamiento de la intención turística de los pacientes con discapacidad visual. Sin embargo, las normas subjetivas no tienen un efecto significativo en la intención de comportamiento turístico de las personas con discapacidad visual.

Las personas con discapacidad y las personas sanas tienen derecho al turismo. Pocas investigaciones turísticas se centran en las personas con discapacidad visual, y no se presta la debida atención a los factores que influyen en el comportamiento de las personas con discapacidad visual. Este estudio amplió el modelo teórico de la teoría del comportamiento planificado y proporcionó una nueva perspectiva para entender la intención de comportamiento de viaje de las personas con discapacidad visual.

The purpose of this paper is to address the concern of some stainless steel users. To understand the effect of surface white spots on corrosion performance of stainless steel.

White spots appeared on some component surfaces made of 316 L stainless steel in some industrial applications. To address the concern about the pitting performance in the spot areas, the pitting corrosion potential and corrosion resistance were measured in the spot and non-spot areas by means of potentiodynamic polarization and electrochemical impedance spectroscopy and the two different surface characteristics were analytically compared by using optical microscopy, laser confocal microscopy, scanning electron microscopy, x-ray diffraction, energy dispersive spectroscopy and auger energy spectroscopy. The results indicated that the pitting performance of the 316 L stainless steel was not negatively influenced by the spots and the white spots simply resulted from the slightly different surface morphology in the spot areas.

The white spots are actually the slightly rougher surface areas with some carbon-containing species. They do not reduce the pitting resistance. Interestingly, the white spot areas even have slightly improved general corrosion resistance.

Not all surface contamination or roughening can adversely affect the corrosion resistance of stainless steel.

Stainless steel components with such surface white spots are still qualified products in terms of corrosion performance.

The surface spot of stainless steel was systematically investigated for the first time for its effect on corrosion resistance and the conclusion was new to the common knowledge.

A lot of people share their living or travelling experiences about cities by writing posts on social media. Such posts carry multi-dimensional information about the characteristics of cities from the public’s perspective. This paper aims at applying text mining technology to automatically extract city images, which are known as how observers perceive the status of the city, from these social media texts.

This paper proposes a data processing pipeline for automatic city image extraction and applies sentiment analysis, timing analysis and contrastive analysis in a case study on Wuhan, a central China megacity. Specifically, the city image constructed with social media text and the expected policy outcomes by the government are compared.

Results reveal gaps between the public’s impression and the strategic goals of the government in traffic and environment.

This study contributes a novel approach to assess government performance by complementary data from social media. This case study implies the value of social media-based city image in the identification of gaps for the optimization of government performance.

Extends the concept of e‐service to the whole phase of manufacturing. Develops an e‐service platform prototype based on this concept with Java Web solution including the mobile agent broking technologies and application service provider (ASP) principle. The key point to implement the platform is to enable an open Web information service infrastructure for the whole product manufacturing chain. Inside this infrastructure, product‐specific online manufacturing system can be created by means of using a kind of bidding model. All users participating in the manufacturing process are able to cooperatively finish manufacturing tasks in real time through sharing the same platform. With the help of BOM flow, the global information service flow can be controlled easily. In addition, the legacy hardware/software can also be encapsulated with aglets that are Java mobile agents. As to new ASP software packages, they can be configured simply via the plug and play mode to the e‐service platform. In this way, the on‐line networked manufacturing can be tested.