Search results

This paper aims to propose a robotic automation system for processing special-shaped thin-walled workpieces, which includes a measurement part and a processing part.

In the measurement part, to efficiently and accurately realize the three-dimensional camera hand-eye calibration based on a large amount of measurement data, this paper improves the traditional probabilistic method. To solve the problem of time-consuming in the extraction of point cloud features, this paper proposes a point cloud feature extraction method based on seed points. In the processing part, the authors design a new type of chamfering tool. During the process, the robot adopts admittance control to perform compensation according to the feedback of four sensors mounted on the tool.

Experiments show that the proposed system can make the tool smoothly fit the chamfered edge during processing and the machined chamfer meets the processing requirements of 0.5 × 0.5 to 0.9 × 0.9 mm².

The proposed design and approach can be applied on many types of special-shaped thin-walled parts. This will give a new solution for the automation integration problem in aerospace manufacturing.

A novel robotic automation system for processing special-shaped thin-walled workpieces is proposed and a new type of chamfering tool is designed. Furthermore, a more accurate probabilistic hand-eye calibration method and a more efficient point cloud extraction method are proposed, which are suitable for this system when comparing with the traditional methods.

Building Information Modeling (BIM) competitions are a beneficial approach to enhance BIM education, offering students practical experience in BIM application, including mastering workflows and technical tools. However, research exploring the individual perceptions influencing participation intentions and behaviors in BIM competitions is limited. Therefore, this study aims to investigate the factors affecting university students' behavioral intention and behavior in BIM competitions, providing theoretical support for BIM competitions and educational reform.

This study employs the Structural Equation Modeling (SEM) based on the Unified Theory of Acceptance and Use of Technology (UTAUT) framework to analyze the factors influencing BIM competition participation among 970 Architecture, Engineering, and Construction (AEC) university students.

The results of the study show that social influence, attitude, and self-efficacy play critical roles in shaping students' intentions to participate in BIM competitions. Furthermore, self-efficacy, facilitating conditions, and behavioral intention significantly influence students' actual engagement in such competitions. Surprisingly, effort expectancy negatively influences intentions, as less challenging tasks can lead students to perceive their participation as less impactful on their skills and learning, reducing their behavioral intention to participate.

This research provides valuable insights into the effectiveness of BIM competitions in enhancing BIM education for AEC students. Extending the UTAUT model to include self-efficacy and attitude, provides a novel perspective for understanding students' intentions and behaviors regarding BIM competitions. The study’s theoretical support proposes incorporating BIM competitions to augment BIM teaching methods and offers suggestions for advancing the efficacy of students' involvement in BIM competitions within higher education, thus contributing to educational reform in the AEC sector.

The purpose of this paper is to investigate the feasibility of solving turbulent flows based on smoothed finite element method (S-FEM). Then, the differences between S-FEM and finite element method (FEM) in dealing with turbulent flows are compared.

The stabilization scheme, the streamline-upwind/Petrov-Galerkin stabilization is coupled with stabilized pressure gradient projection in the fractional step framework. The Reynolds-averaged Navier-Stokes equations with standard k-epsilon model are selected to solve turbulent flows based on S-FEM and FEM. Standard wall functions are applied to predict boundary layer profiles.

This paper explores a completely new application of S-FEM on turbulent flows. The adopted stabilization scheme presents a good performance on stabilizing the flows, especially for very high Reynolds numbers flows. An advantage of S-FEM is found in applying wall functions comparing with FEM. The differences between S-FEM and FEM have been investigated.

The research in this work is limited to the two-dimensional incompressible turbulent flow.

The verification and validation of a new combination are conducted by several numerical examples. The new combination could be used to deal with more complicated turbulent flows.

The applications of the new combination to study basic and complex turbulent flow are also presented, which demonstrates its potential to solve more turbulent flows in nature and engineering.

This work carries out a great extension of S-FEM in simulations of fluid dynamics. The new combination is verified to be very effective in handling turbulent flows. The performances of S-FEM and FEM on turbulent flows were analyzed by several numerical examples. Superior results were found compared with existing results and experiments. Meanwhile, S-FEM has an advantage of accuracy in predicting boundary layer profile.

Some researchers argue that consumers’ lack of knowledge is an important factor increasing risk for a new product derived from emerging agricultural technology. The purpose of this paper is to discuss the potential impacts and the differential effects of subjective and objective perceptions on Chinese consumers’ preferences for the application of a novel biotechnology.

Taking transgenic technology as an example and employing data from a survey of 1,000 consumers in Jiangsu Province, the authors develop a mixed-process regression model based on Fishbein’s multiple attributes attitude model.

The results suggest that there are apparent differences between Chinese consumers’ subjective perceptions and objective perceptions concerning transgenic technology and genetically modified (GM) food, and there exists certain selective perceptions of the emerging biotechnology. Having a subjective perception concerning transgenic technology has a positive effect on consumers’ overall attitudes, whereas subjective and objective perceptions concerning GM foods have a negative effect on consumers’ overall attitudes. Self-identification generated from subjective perception occupies a dominant position in determining consumers’ attitudes.

Consumers’ attitudes regarding an agricultural product depend on their perception of the attributes of the technology used to produce such a product. This study attempts to distinguish and empirically test urban consumers’ subjective perceptions (self-assessed or perceived) and objective perceptions (obtained from a test) about transgenic technology and GM foods and the impact of these four types of perception on the consumers’ attitudes regarding the application of transgenic technology. In this paper, the authors construct a mixed-process regression model to address the possible endogeneity of the perception variables.

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.

The results showed that the use of a magnetic marker could relatively accurately reflect the fracture pattern inside the rock-like material (RLM).

This study investigated the internal structure and fracture pattern of a fractured RLM. Magnetized iron oxide powder, which was used as a magnetic marker, was mixed with water and glue to form a magnetic slurry, which was subsequently injected into a fractured RLM. After the magnetic slurry completely filled the cracks inside the RLM and became cemented, the distribution and magnitude of the magnetic field inside the RLM were determined using a three-dimensional (3D) magnetic field imaging system.

A model for determining the magnetic field strength was developed using MATLAB.

This model of 3D magnetic will further be used as a finite element tool to simulate and image cracks inside the rock.

This study aims to using Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and scanning electron microscope/energy dispersive Xray spectrometer to identify different automotive coatings for forensic purpose.

Two four-layered samples in a hit-and-run case were compared layer by layer with three different methods. FTIR spectroscopy was used to primarily identify the organic and inorganic compositions. Raman spectrum and scanning electron microscope/energy dispersive Xray spectrometer (SEM-EDS) were further used to complement the FTIR results.

Two weak and tiny peaks in one layer found between two samples by FTIR, Raman microscope and SEM-EDS verified the result of differences. The study used the three instruments in combination and found it’s effective in sensing coatings, especially in the inorganic additives.

Using these three instruments in combination is more accurate than individually in multilayered coating analysis for forensic purpose.

The three different instruments all present unique information on the composition, and provided similar and mutually verifiable results on the two samples.

With this method, scientists could identify and discriminate important coating evidences with tiny but characteristic differences.

This paper aims to use a negative perspective to investigate the effects of perceived deceptiveness and pressure on consumer donation and their underlying mechanisms in the context of asking for donations.

Study 1 used a qualitative approach to clarify the categories and dimensions of the research variables and explore their relationships. Study 2 empirically tested the hypotheses by combining a fictitious context and a real context related to asking for donations.

In the qualitative study, the data provided sufficient evidence to support the relationships in the theoretical model. The results of the empirical study showed that perceived deceptiveness negatively influences consumer donation, while perceived pressure positively affects donation amount. Notably, the discomfort of potential donors plays an important role in mediating these relationships.

This paper suggests a way for charities to raise more money, i.e. by cooperating with companies with good reputations, limited scandals and transparent supervisory mechanisms. Meanwhile, solicitors should pay attention to the adverse effects of discomfort to avoid generating resentment among consumers.

First, to the best of the authors’ knowledge, this is the first study to use a negative perspective to examine the effects of perceived deceptiveness and pressure on consumer donation. Second, the use of cognitive dissonance theory to highlight the role of discomfort represents a novel contribution to the literature. Third, using a mixed-methods approach to achieve a robust conclusion provides valuable insights and extends the existing literature.

This paper aims to investigate the electrochemical corrosion behavior of a five-layer Al alloy composites (4343/4047/3003/4047/4343) with a thickness of 0.2 mm in NaCl solution.

Electrochemical impedance spectroscopy, polarization curve and morphology analyses were used to study the corrosion behavior of the Al alloy composites from cross-sectional and plane directions.

The corrosion resistance of the surface from the plane direction was higher than that from the cross sections. Si-enrich particles were observed in the outer 4047/4343 layer, and AlFeCuMnBi phases were identified in the core 3003 layer. The galvanic coupling between the Si-enrich particle and the Al matrix accelerated the dissolution Al matrix.

This work lays the experimental foundation for corrosion mechanism of the Al alloy composite plate.

To study fracture characteristics of jointed rock masses under blasting load, the RFPA2D analysis software for dynamic fracture of rocks based on the finite element method and statistical damage theory was used.

On this basis, this research simulated the fracture process of rock masses in blasting with different joint geometrical characteristics and mainly analysed the influences of distance from joints to blasting holes, the length of joints, the number of joints and joint angle on fracture of rock masses.

The calculation results show that with the constant increase of the distance from joints to blasting holes, the influences of joints on blasting effects of rock masses gradually reduced. Rock masses with long joints experienced more serious damages than those with short joints. Damages obviously increased with the changing from rock masses without joints to rock masses with joints, and when there were three joints, the further increase of the number of joints had unobvious changes on blasting effects of rock masses. Joints showed significant guidance effect on the propagation of cracks in blasting: promoting propagation of main vertical cracks deflecting to the ends of joints.

The research results are expected to provide some theoretical bases in practical application of engineering blasting.