Search results

This study aims to the complex and unpredictable terrain environment of the Qinghai-Tibet Plateau scientific research station, such as cement road, wetland, gravel desert, snowfield, ice surface, grassland, slimy ground, steep slope, step, etc., a reconfigurable walking mechanism based on two movement modes of wheel and triangular crawler was proposed.

By analyzing the deformation mechanism of the walking mechanism, a reconfigurable wheel-crawler-integrated walking mechanism and the configuration scheme are designed. The analysis of the kinematics and mechanical properties of the swing arm system and the deformation mechanism of the walking mechanism.

The reconfigurable wheel-crawler-integrated walking mechanism can be switched between the wheel and triangular crawler modes by driving the deformation mechanism. Through the numerical simulation of its movement process, and the trial production and experiment of the prototype, indicates the validity of the reconfigurable wheel-crawler-integrated walking mechanism design.

The work of this paper provides a reconfigurable wheel-crawler-integrated-walking mechanism, which can be used by robots in the Qinghai-Tibet Plateau scientific research station. It has excellent reconfigurability and can effectively improve the robot’s adaptability to complex terrain.

The purpose of this paper is to present the mechanical design and stability analysis of a new stair‐climbing robotic wheelchair.

A prototype stair‐climbing robotic wheelchair is constructed comprising a pair of rotational multi‐limbed structures pivotally mounted on opposite sides of a support base. The short arm, long arm, and triangular support structures within each rotational multi‐limbed structure rotate under the actuating effects of epicyclical gear trains.

The robotic wheelchair ascends and descends stairs in a statically stable manner and has an efficient planar navigation capability.

In its current state of development, the robotic wheelchair is controlled and powered remotely via umbilical cords rather than an onboard processor and power supply.

The robotic wheelchair provides an effective solution for enhancing the mobility of the elderly and disabled.

The rotational multi‐limbed mechanisms are developed to ensure the stability of the sitting base at all stages of the stair navigation maneuver without the need for additional servo‐mechanism. The proposed robotic wheelchair shows the simplification of the associated operation process.

This paper aims to develop a climbing robot to help people inspect lamps of high-mast lighting.

The robot consists of driving mechanism, suspension mechanism and compression mechanism. The driving mechanism is realized by link chains and sprockets, which are arranged opposite to each other, to form a dual caterpillar mechanism. The compression mechanism squeezes the caterpillar, and rubber feet “grasps” the steel rope to generate enough adhesion forces. The suspension mechanism is used to compensate the contraction or extension of the chains. The robot is equipped with a DC motor with a rated power of 250 W and a wireless module to communicate with the operator’s console. The dynamic model of the robot and the control strategy is derived, and the stability of the controller is proofed.

The payload experiment shows the robot can afford up to 3.7 times payload versus its own weight. Even when the payload is 30 kg, the robot can maintain a speed of the 1 m/s. The experiments also show that the tracking error of the robot reaches zero.

The proposed moving mechanism has a high load/weight ratio, which is a verified solution for the cable inspection purpose.

A rope climbing robot for high mast lighting inspection is proposed. The developed mechanism can reach a speed of 1 m/s with the payload of 30 kg, while its own weight is only 15.6 kg. The payload/weight ratio of the robot is 2.24; this value is rather good in many climbing robots reported in other renowned journal.

We analyze the structure and the dynamics of a field, drawing on data from organizational public behavior in the digital sphere. Organizational self-representations afford rich insights into how organizations position themselves with regard to their peers, both in terms of web page language and hyperlink affiliations. Our empirical example is the lively and important discussion of the social impact of nonprofit organizations. We follow how it has evolved from 2011 to 2018 and with what consequences. We begin with portraits of the discursive movements of powerful, individual organizations, where we observe extensive changes. These portraits show how influential organizations alter their public faces. We then analyze discourse at the field level, which is surprisingly stable even though individual organizations change their discursive and relational positions frequently. Finally, we turn to groups of organizations with similar positions and highlight their ability to integrate vocabularies of other groups. Here we observe that a lingua franca increases integration at the field level, while affording distinction with individual organizations’ positioning. We conclude with a discussion of complementary research avenues that can advance the relational and linguistic view we present in this paper.

To present a new special explosive ordnance disposal (EOD) robot designed to operate onboard airplanes.

The design approach adopted is multidisciplinary: mechanical and control architectures are conceived simultaneously. Modularity and lifecycle are considered. Motion and EOD tasks are controlled in tele‐operation.

A new EOD robot was designed in detail and it is ready to be built. A dynamic simulator has been written and set‐up, including a virtual reality module. The simulator is used to define the control logics. Simulation results are satisfactory. The simulator can be used as a training platform for the bomb squads.

The intent to keep the cost of the robot low conditioned the selection of the materials. Only aluminium and standard composites (like carbon fibers composites) have been used. A higher degree of freedom of the arm could increase the usability of the system; to limit the cost, the degree of freedom was limited to seven. A decision support system based on an expert system interfaced with the simulator could improve the performance of the system.

A new EOD robot will be built and commercialised soon by the industrial partner Ansaldo Ricerche.

The EOD robots available for use inside aircrafts are discussed. A new system named AirEOD is presented, including mobile platform, dexterous arm and all related design and control issues.

Mooring chains used to stabilise offshore floating platforms are often subjected to harsh environmental conditions on a daily basis, i.e. high tidal waves, storms, etc. Therefore, the integrity assessment of chain links is vital, and regular inspection is mandatory for offshore structures. The development of chain climbing robots is still in its infancy due to the complicated climbing structure presented by mooring chains. The purpose of this paper is to establish an automated climbing technique for mooring chain inspection.

This paper presents a Cartesian legged tracked-wheel crawler robot developed for mooring chain inspection. The proposed robot addresses the misalignment condition of the mooring chains which is commonly evident in in situ conditions.

The mooring chain link misalignment is investigated mathematically and used as a design parameter for the proposed robot. The robot is validated with laboratory-based climbing experiments.

Chain breaking can lead to vessel drift and serious damage such as riser rupture, production shutdown and hydrocarbon release. Currently, structural health monitoring of chain links is conducted using either remotely operated vehicles which come at a high cost or by manual means which increase the danger to human operators. The robot can be used as a platform to convey equipment, i.e. tools for non-destructive testing/evaluation applications.

This study has upgraded a previously designed magnetic adhesion tracked-wheel mooring chain climbing robot to address the misalignment issues of operational mooring chains. As a result of this study, the idea of an orthogonally placed Cartesian legged-magnetic adhesion tracked wheel robotic platform which can eliminate concerns related to the misaligned mooring chain climbing has been established.

This paper aims to propose a bed and breakfast (B&B) recommendation method that takes into account review timeliness and user preferences to help consumers choose the most satisfactory B&B.

This paper proposes a B&B ranking method based on improved intuitionistic fuzzy sets. First, text mining and cluster analysis are combined to identify the concerns of consumers and construct an attribute set. Second, an attribute-level-based text sentiment analysis is established. The authors propose an improved intuitionistic fuzzy set, which is more in line with the actual situation of sentiment analysis of online reviews. Next, subjective-objective combinatorial assignments are applied, considering the consumers’ preferences. Finally, the vlsekriterijumska optimizacija i kompromisno resenje (VIKOR) algorithm, based on the improved score function, is advised to evaluate B&Bs.

A case study is presented to illustrate the use of the proposed method. Comparative analysis with other multi-attribute decision-making (MADM) methods proves the effectiveness and superiority of the VIKOR algorithm based on the improved intuitionistic fuzzy sets proposed in this paper.

Proposing a B&B recommendation method that takes into account review timeliness and user customization is the innovation of this paper. In this approach, the authors propose improved intuitionistic fuzzy sets. Compared with the traditional intuitionistic fuzzy set, the improved intuitionistic fuzzy set increases the abstention membership, which is more in line with the actual situation of attribute-level sentiment analysis of online reviews.

The purpose of this paper is to present a multidimensional evaluation of brand equity performance incorporating dimensions adopted from the balance scorecard (BSC) approach to business performance.

In this study, text mining is used for automatic extraction of valuable information from textual data such as the financial reports of firms. Instead of expert opinions, linguistic scales built upon outcomes of text mining are used as inputs for decision-making. The proposed model combines fuzzy DEMATEL (FDEMATEL), fuzzy ANP (FANP), fuzzy TOPSIS (FTOPSIS) and fuzzy VIKOR (FVIKOR) methods for weighting criteria and ranking alternatives.

Using data from five privatized firms in Turkey, the study’s findings demonstrate that the customer is the most important dimension of brand equity performance evaluation. Cash flow and brand loyalty are identified as the most important criteria in the measurement of brand equity performance.

Findings highlight the importance of firms taking action to increase consumer perceptions, attitudes and behaviors in the privatization processes. For this purpose, privatized firms need to understand the expectations of customers to increase customer satisfaction and loyalty and therefore improve brand equity.

The paper contributes to literature in several important ways. First, by adopting the BSC approach, it proposes a holistic and a multidimensional model for measuring brand equity performance. Second, the study offers a novel methodology using a hybrid multi-criteria decision-making model designed for the fuzzy environment. Third, the study uses the knowledge extraction tool of text mining in the fuzzy decision-making process. Finally, the study evaluates the brand equity performance of privatized firms in an emerging country context.

The paper aims to describe the design and manufacturing process of a tele‐operative urban search and rescue tracked robot and discuss the advantages of a proposed novel track arrangement and other additional mechanisms, which help the robot to gain high manoeuverability on rough terrains.

Using a simplified static model, required torques are calculated and appropriate mechanisms and geometric dimensions are chosen. Next, stress distribution is analyzed in the parts, deploying both classic and numerical methods and to complete the procedure parts are fabricated and assembled together. The architecture of control system and the user interface is introduced. Finally, the robot is tested on a standard test arena and the results are compared with another similar search robot.

A tele‐operated rescue robot with considerable capabilities is designed and manufactured. The novel track arrangement and new rear arm's mechanism are tested and compared with a robot in the same class and higher performance is achieved on the evaluation.

Although the implemented locomotion mechanism is the common tracked type, adding the center tracks and arrangement of arms are original ideas which help the robot to gain high manoeuverability. The proposed rear arm's linkage mechanism generates a limited rotational path and has an acceptable strength for a robot working in rescue missions.

With multiple-related organizations, worldwide infections, deep economic recession and public disorder, and large consumption amount of anti-epidemic resources, the coronavirus disease 2019 (COVID-19) has been defined as a public health emergency of international concern (PHEIC). Nowadays, Wuhan has recovered from the pandemic disaster and reentered normalization. The purposes of this study are to (1) summarize organization collaboration patterns, successful experience and latent defects under across-stage evolution of Wuhan's cooperation governance mode against the pandemic, and on the basis, (2) reveal how the COVID-19 development trends and organizations' collaborative behaviors affected each other.

Detailed content analysis of online news reports covering COVID-19 prevention and control measures on the website of Wuhan Municipal Government was adopted to identify organizations and their mutual collaborative interrelationships. Four complex network (CN) models of organization collaboration representing the outbreak, preliminary control, recession and normalization stages, respectively, were established then. Time-span-based dynamic parameter analyses of the proposed networks, comprising network cohesiveness analysis and node centrality analysis, were undertaken to indicate changes of global and local characteristics in networks.

First, the definite collaborative status of Wuhan Headquarters for Pandemic Prevention and Control (WHPPC) has persisted throughout the period. Medical institutions and some other administrations were the most crucial participants collaborating with the WHPPC. Construction-industry organizations altered pandemic development trends twice to make the situation controllable. Media, large-scale enterprises, etc. set about underscoring themselves contributions since the third stage. Grassroots cadres and healthcare force, small and medium-sized enterprises (SMEs), financial institutions, etc. were essential collaborated objects. Second, four evolution mechanisms of organization collaboration responding to the COVID-19 in Wuhan has been proposed.

First, universality of Wuhan-style governance experience may be affected. Second, the stage-dividing process may not be the most appropriate. Then, data source was single and link characteristics were not considered when modeling.

This study may offer beneficial action guidelines to governmental agencies, the society force, media, construction-industry organizations and the market in other countries or regions suffering from COVID-19. Other organizations involved could also learn from the concluded organizations' contributions and four evolution mechanisms to find improvement directions.

This study adds to the current theoretical knowledge body by verifying the feasibility and effectiveness of investigating cooperation governance in public emergencies from the perspectives of analyzing the across-stage organization collaboration CNs.