Search results

The purpose of this paper is to explore the effect of surface roughness characterized by fractal geometry on squeeze film damping characteristics in damper of the linear rolling guide, which has not been studied so far.

The stochastic model of film thickness between rail and damper is established by using the two-variable Weierstrass–Mandelbrot function defining multi-scale and self-affinity properties of the rough surface topography. The stochastically averaged Reynolds equation is solved by using the variables separation method to further derive the film pressure distribution, the damping coefficient, the damping force and squeeze film time. The effect of surface roughness on squeeze film damping characteristics of the damper is analyzed and discussed through simulation.

By comparing cases of the rough surface for different fractal parameters and the smooth surface, it is shown that for the isotropic roughness structure, the presence of surface roughness of the damper decreases the squeeze film damping characteristics. It is found that roughness effect on the damping coefficient is associated with the film thickness. In addition, the vibration amplitude effect is negligible for the damper of the linear rolling guide.

To investigate the random surface roughness effect, the rough surface topography of damper of the linear rolling guide is characterized by using the fractal method instead of the traditional mathematical statistics method.

Construction enterprises are achieving the goal of production safety by increasingly focusing on the critical factor of “human” and the impact of individual characteristics on safety performance. Emotional intelligence is categorized into three models: skill-based, trait-based and emotional learning systems. However, the mechanism of action and the internal relationship between emotional intelligence and safety performance must be further studied. This study intends to examine the internal mechanism of emotional intelligence on safety performance in construction projects, which would contribute to the safety management of construction enterprises.

A structural equation model exploring the relationship between emotional intelligence and safety performance is developed, with political skill introduced as an independent dimension, situational awareness presented as a mediator, and management safety commitment introduced as a moderator. Data were collected by a random questionnaire and analyzed by SPSS 24.0 and AMOS 26.0. The structural equation model tested the mediation hypothesis, and the PROCESS macro program tested the moderated mediation hypothesis.

The results showed that construction workers' emotional intelligence directly correlates with safety performance, and situational awareness plays a mediating role in the relationship between emotional intelligence and the safety performance of construction workers. Management safety commitment weakens the positive predictive relationships between emotional intelligence and situational awareness and between emotional intelligence and safety performance.

This research reveals a possible impact of emotional intelligence on safety performance. Adding political skills to the skill-based model of emotional intelligence received a test pass. Political skill measures the sincere and cooperative skills of construction workers. Using people as a critical element plays a role in the benign mechanism of “Emotional Intelligence – Situational Awareness – Safety Performance.” Improving emotional intelligence skills through training, enhancing situational awareness, understanding, anticipation and coordination and activating management environment factors can improve safety performance. Construction enterprises should evaluate and train workers' emotional intelligence to improve workers' situational awareness and safety performance.

As an important connecting component, the reliability of aluminium alloy welded joints influences the whole structural effectiveness and stability of equipment. The purpose of this paper is to propose a novel reliability estimation approach to the welded joints based on time-transformed Wiener process with automatic image measurement of crack growth. The crack length information of the welded joints is incorporated into reliability analysis to reflect the product time-varying characteristics.

The proposed approach is superior to other crack growth estimations in that it innovatively introduce a non-contact and flexible photogrammetry technique.First, on-line crack growth images of aluminium alloy welded joints are acquired by the designed monitor system. Second, crack length is calculated with image measurement, then the crack growth data during the manufacturing process is prepared. Finally, a time-transformed Wiener process is used to modeling the degradation, and reliability estimation is carried out with Wiener model. The approach has been validated on five 7075-T7351 welded joint samples.

The method has a twofold task: first, the extraction of crack length growth data by a sequence of image processing. The main step is to model the crack skeleton with crack skeleton tree, and remove it edges to calculate the length of crack; second, the prediction of crack growth and reliability estimation.

The limitation of proposed method should not be ignored. The pixel/mm scale should be calibrated in advance that means once we have built the monitor system, the relative position of the CCD camera and the surveyed crack cannot change anymore. It has reduced the flexibility. To improve this, we can obtain binocular vision in crack image measurement. The 3-D measurements could solve calibration problem and provide more information, such as the depth and the orientation of crack to research. Therefore, future work can be centered on the improvement of monitor system and measurement precision.

In the paper a novel method to estimate reliability of crack growth from welded joint based on image measurement has been presented. This method could be widely applied in different filed of manufacturing systems, reliability engineering and structural analysis.

Many mobile devices today are equipped with diversified sensors that enable the acquisition of rich user context (e.g. GPS location, phone activity) for application utilization. With the growing usage of mobile devices in daily life, the problem of conveniently and promptly searching a piece of content that a user has viewed on his/her device before becomes more and more crucial. This paper aims to propose a context‐based query processing framework called UCQP that supports unstructured queries for content search in a user's access history.

Beyond the keywords related to the content properties, a context query in the framework is specified with freeform phrases that describe high‐level mobile contexts of the user at a previous time when the user viewed the searched content.

Experimental results on a prototype system of the framework illustrate its good accuracy and small response time.

To tolerate the incompleteness and inaccuracy in user query texts caused by fading human memory, the authors develop several semantic query parsers that are tailored for different types of contexts using natural language processing and information retrieval techniques. The authors further propose a similarity model to rank the multiple result contents of a query by comparing context entities specified in the query and historical context values associated with each result.

The purpose of this paper is to explore how the Chaozhou-speaking communities in northeast Guangdong Province dealt with new barriers of border control during the 1950s, and how they circumvented these institutional obstacles to leave China for Hong Kong and Southeast Asia. The emigration process was reshaped by new social and political forces in Maoist China. How did the Chaoshan people apply for the travel permit to leave China? How did they enter the hosting countries? How did the emigration experience influence the identity formation of Chaoshan Chinese in the 1950s?

This paper draws on archival sources, memoirs and interviews to demonstrate the ways in which Chaoshan people pursued new strategies of emigration during the 1950s.

In Maoist China, the application for an entry-exit permit was a rather complicated bureaucratic process for ordinary people. One needs to consider the class status, geographical origins and overseas connections of the applicants as well as the changing official policies toward overseas Chinese.

This paper emphasizes on the impacts of emigration experience on the identity formation of Chaoshan people and the incremental transformation of these emigrant communities in Guangdong Province.

This scholarly finding throws light on the transformation of Chaoshan from a fluid, mobile maritime environment to an increasingly state-centric agrarian society during the 1950s.

This paper is an original scholarly study of the history of Chaoshan communities in South China and their emigration to Southeast Asia.

In order to find a way to create the artistic conception of modern landscape space, the spatial analysis of Daguanyuan is carried out from the perspective of literature in order to find out the method of creating the artistic conception of modern landscape space. Adopting the method of general to special, from theory to practice, the argument with special significance is analyzed from the most common phenomena, and this argument is applied to the method of practical cases. The results show that Daguanyuan space in literature needs the audience's ability to understand words, the perception of space in film and television needs the audience's strong memory and imaginative thinking, while the perception of Daguanyuan space in garden art needs only basic discrimination ability. After analyzing the effect of Daguanyuan space construction from the literary perspective, it is believed that the writing techniques of starting point - development - climax - ending, wanting to carry forward first and restraining first, and reserving foreshadows in literature can be used for reference in modern landscape design.

This study investigates the impact of board independence on firm risk of Vietnamese listed firms and the moderating effect of capital expenditure on this relationship.

This paper applies fixed effects and dynamic generalized method of moments (GMM) models to examine hypothesized associations between the proportion of nonexecutive directors and stock return volatility, as well as the moderating effect of capital expenditure. The robustness tests are implemented by applying alternative measures of overinvestment and firm risk.

The results show that the presence of nonexecutive directors on board increases firm risk. However, the combination of nonexecutive ratio and capital expenditure ratio has a significant negative impact on firm risk. The result is also confirmed by the difference between the monitoring role of nonexecutive directors in overinvesting and underinvesting firms.

The results imply that Vietnamese listed firms take stock return volatility into consideration before nominating and appointing nonexecutive directors into their board, especially in overinvesting firms. From another perspective, the shift toward having a majority of nonexecutive directors on boards can play a significant role in pursuing a stable or risky business strategy.

This paper investigates the influences of nonexecutive directors on firm risk in the context of Vietnam.

The paper is prompted by the US–China trade war and its implications for the sustenance of the multilateral trading system. The two rivals resorted to “self-help” without recourse to the World Trade Organization (WTO) dispute settlement system, flouting the WTO as an adjudicator in trade disputes. This paper aims to analyze the drawbacks in the settlement system and examines the urgent need for a retroactive remedy.

This paper adopts desk-review and jurisprudential analysis of the relevant rulings of the WTO dispute settlement body. Using desk-review, primary sources such as the relevant domestic legislations invoked by the USA and China to trigger the trade war were discussed and critically analyzed.

This paper finds that the unilateral and protectionist actions that characterize the trade war can be linked to the loss of confidence in WTO remedies to redress members’ retroactive economic losses. This finding is useful in arguing for the incorporation of a retrospective monetary remedy to forestall the reoccurrence of a similar trade war and save the WTO from being dysfunctional.

Although, whether there should be retroactive remedies in the settlement system has been long debated, this paper makes a significant contribution by highlighting why the drawbacks in the settlement system have become so prominent in the context of this trade war. This paper strengthens the urgent need for WTO dispute settlement reform to prevent a reoccurrence of another global distortion of trade.

The emergence of new digital technologies in the 21st century has propelled individuals to use technology in their daily lives. Individuals now require a specific set of skills, competencies and knowledge to use these devices efficiently, intelligently yet with responsibility. The purpose of this research was to design, develop and validate a digital literacy scale (DLS) using the exploratory factor analysis (EFA).

A quantitative research methodology was used for this study, whereby a unipolar 5 point Likert scale self-report questionnaire was designed to measure the digital skills of the participants. Digital literacy was divided into an exhaustive and broad list of six modules-media literacy, information literacy, communication literacy, technology literacy, visual literacy and computer literacy. The questionnaire was administered to a sample of the 2,755 Year 12 and Year 13 students of randomly selected 33 secondary school students in Fiji. Sample adequacy of the sample was tested using the Kaiser-Meyer-Olkin test.

The EFA results prove the existence of the six modules of digital literacy that are being utilized in this research to design the DLS. The factor loadings or the correlation coefficients range from 0.3 to 0.8; therefore, all the 60 items were kept to design the DLS. The Cronbach Alpha value of 0.90 confirmed the internal consistency and reliability of the newly designed DLS.

The research limitation of the study was the sample size. A broader sample would have made the results better. Research implications are; there is no scale in the south Pacific to measure digital literacy. The newly designed and developed scale is the first one that can be used to measure the digital literacy of the south Pacific populace and bridge the gap of the digital divide.

The developed and validated scale can be used to measure the digital literacy of individuals both in the south Pacific and beyond. The scale covers important aspects of the much needed 21st century skills. Once digital literacy is measured, relevant stakeholders can develop instruments to improve the digital literacy of individuals.

The DLS can prove to be an important tool for society. In the 21st century people are required to have digital literacy to survive and thrive. Thus this tool can be used to measure digital literacy and further improve the digital literacy of the people.

The framework has been adopted from the work of Covello (2010) however, the definitions of digital literacy and other literacies are modified to meet the requirements of the 21st century. The tool is unique in its nature in the south Pacific and beyond. Looking at the digital literacy tools in literature, this tool covers all the aspects of digital literacy in the 21st century.

The peer review history for this article is available at: https://publons.com/publon/10.1108/OIR-10-2021-0532.