Song Quan, Yong Guo, Xuedong Liu, Zhewu Chen and Yudi Liu
This paper aims to study the lubrication and sealing performance on the textured piston pair under the cross action of the shape and structure parameters. This paper further…
Abstract
Purpose
This paper aims to study the lubrication and sealing performance on the textured piston pair under the cross action of the shape and structure parameters. This paper further carries out the optimization design of low energy consumption hydraulic impact piston pair.
Design/methodology/approach
Based on the characteristics of the ring gap seal piston pair, the flow field analysis model of the whole film gap is established for its periodic treatment. The friction power loss of the piston pair is defined as the evaluation index of the lubrication performance and the leakage power loss as the evaluation index of the sealing performance. The orthogonal test design and CFD software were used to analyze the lubrication and sealing performance of the textured piston pair.
Findings
The cross action of shape and structure factors has a great influence of the lubrication and sealing performance on the textured piston pair. Clearance and shape parameters have great influence on it, while seal length and depth diameter ratio have little influence. The sealing performance of conical textured piston pair is good, while the lubrication performance of square textured piston pair is good. The primary and secondary order of influence of shape and structure on energy consumption on piston pair is B (seal clearance) > C (texture shape) > D (area ratio) > A (seal length) > E (depth diameter ratio).
Originality/value
Breaking the defect of local optimization design on traditional piston pair structure, then find the matching relationship of structural parameters on textured piston pair. Further improve the lubrication and sealing performance of the piston pair, and provide reference for the global optimization design of the low energy consumption hydraulic impact piston pair.
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Song Quan, Guo Yong, Gong Jun, Xuedong Liu, Jin Yongping and Yang Shuyi
This paper aims to study the frictional performance of reciprocating pair with high velocity by using hydrodynamic lubrication principle and fish scale textured piston model.
Abstract
Purpose
This paper aims to study the frictional performance of reciprocating pair with high velocity by using hydrodynamic lubrication principle and fish scale textured piston model.
Design/methodology/approach
Based on the idea of function characteristic approximation and coordinate change, a mathematical representation model of imitating fish scale texture pit section is established. According to the principle of dynamic pressure lubrication of the textured fluid, a three-dimensional numerical model of flow field for fish scale texture is established without considering cavitation. Numerical analysis of the model carp scale texture unit by orthogonal experimental design and FLUENT software is carried out.
Findings
Effects of fish scale pit texture on friction properties for a reciprocating pair piston surface with high velocity (impact piston) are acquired. Effects of texture characterization parameters and flow rate on the surface friction performance for impact piston are found. Effects of different characteristic parameters combination of imitating fish scale texture on friction performance for impact piston surface are obtained.
Originality/value
The model is an effective tool to study the friction and wear of reciprocating pair with high velocity. The effects of fish scale textured piston pair supply a theory lead to design the reciprocating pair with better friction performance.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-09-2019-0398
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Gives an in depth view of the strategies pursued by the world’s leading chief executive officers in an attempt to provide guidance to new chief executives of today. Considers the…
Abstract
Gives an in depth view of the strategies pursued by the world’s leading chief executive officers in an attempt to provide guidance to new chief executives of today. Considers the marketing strategies employed, together with the organizational structures used and looks at the universal concepts that can be applied to any product. Uses anecdotal evidence to formulate a number of theories which can be used to compare your company with the best in the world. Presents initial survival strategies and then looks at ways companies can broaden their boundaries through manipulation and choice. Covers a huge variety of case studies and examples together with a substantial question and answer section.
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Xinwang Li, Juliang Xiao, Wei Zhao, Haitao Liu and Guodong Wang
As complex analysis of contact models is required in the traditional assembly strategy, it is still a challenge for a robot to complete the multiple peg-in-hole assembly tasks…
Abstract
Purpose
As complex analysis of contact models is required in the traditional assembly strategy, it is still a challenge for a robot to complete the multiple peg-in-hole assembly tasks autonomously. This paper aims to enable the robot to complete the assembly tasks autonomously and more efficiently, with the strategies learned by reinforcement learning (RL), a learning-accelerated deep deterministic policy gradient (LADDPG) algorithm is proposed.
Design/methodology/approach
The multiple peg-in-hole assembly strategy is designed in two modules: an advanced planning module and a bottom control module. The advanced module is completed by the LADDPG agent, which is used to derive advanced commands based on geometric and environmental constraints, that is, the desired contact force. The bottom-level control module will drive the robot to complete the compliant assembly task through the adaptive impedance algorithm according to the command set issued by the advanced module. In addition, a set of safety assurance mechanisms is developed to safely train a collaborative robot to complete autonomous learning.
Findings
The method can complete the assembly tasks well through RL, and it can realize satisfactory compliance of the robot to the environment. Compared with the original DDPG algorithm, the average values of the instantaneous maximum contact force and contact torque during the assembly process are reduced by approximately 38% and 74%, respectively.
Practical implications
The entire algorithm can also be applied to other robots and the assembly strategy can be applied in the field of the automatic assembly.
Originality/value
A compliant assembly strategy based on the LADDPG algorithm is proposed to complete the automated multiple peg-in-hole assembly tasks.
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Nadine Desrochers, Audrey Laplante, Kim Martin, Anabel Quan-Haase and Louise Spiteri
Most studies pertaining to social tagging focus on one platform or platform type, thus limiting the scope of their findings. The purpose of this paper is to explore social tagging…
Abstract
Purpose
Most studies pertaining to social tagging focus on one platform or platform type, thus limiting the scope of their findings. The purpose of this paper is to explore social tagging practices across four platforms in relation to cultural products associated with the book Casino Royale, by Ian Fleming.
Design/methodology/approach
A layered and nested case study approach was used to analyse data from four online platforms: Goodreads, Last.fm, WordPress, and public library social discovery platforms. The top-level case study focuses on the book Casino Royale, by Ian Fleming and its derivative products. The analysis of tagging practices in each of the four online platforms is nested within the top-level case study. Casino Royale was conceptualized as a cultural product (the book), its derived products (e.g. movies, theme songs), as well as a keyword in blogs. A qualitative, inductive, and context-specific approach was chosen to identify commonalities in tagging practices across platforms whilst taking into account the uniqueness of each platform.
Findings
The four platforms comprise different communities of users, each platform with its own cultural norms and tagging practices. Traditional access points in the library catalogues focused on the subject, location, and fictitious characters of the book. User-generated content across the four platforms emphasized historical events and periods related to the book, and highlighted more subjective access points, such as recommendations, tone, mood, reaction, and reading experience. Revealing shifts occur in the tags between the original book and its cultural derivatives: Goodreads and library catalogues focus almost exclusively on the book, while Last.fm and WordPress make in addition cross-references to a wider range of different cultural products, including books, movies, and music. The analyses also yield apparent similarities in certain platforms, such as recurring terms, phrasing and composite or multifaceted tags, as well as a strong presence of genre-related terms for the book and music.
Originality/value
The layered and nested case study approach presents a more comprehensive theoretical viewpoint and methodological framework by which to explore the study of user-generated metadata pertaining to a range of related cultural products across a variety of online platforms.
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Juan Albacete-Maza, Antonio Fernández-Cano and Zoraida Callejas
Covid-19 pandemic, war, climate emergency and other recent challenges are inflicting tremendous stress to youth. However, death and tragedy are nowadays considered taboo, as there…
Abstract
Purpose
Covid-19 pandemic, war, climate emergency and other recent challenges are inflicting tremendous stress to youth. However, death and tragedy are nowadays considered taboo, as there is generally no standardized nor naturalized discussion on the subject, especially with young people. The current multi-crisis scenario is intensifying the need to incorporate an education on tragedy and resilience in our learning systems. In this context, it is necessary to find suitable teaching resources for this educational challenge that are attractive, entertaining and suitable for children and youth. A resource that meets all these requirements are children’s folk songs (CFSs). Apart from the intrinsic educational potential of music, folk songs have a simplicity and musicality that make them an ideal teaching resource. Considering their oral historical transmission, their survival confirms the attraction that this type of composition causes on children. However, to consider CFSs as an adequate resource to carry out an education for death and tragedy, it is necessary to study whether they present a non-negligible proportion of tragic passages and with enough variety of themes. This paper aims to address the study of the presence of explicit tragic content in Spanish CFSs and thus could be considered a cultural resource with transformative educational potential to develop resilience capabilities on the face of tragedy.
Design/methodology/approach
An analysis of lyrics of 2,558 Spanish CFSs is presented, using a manual content analysis as well as a computerized content analysis with the aim of identifying the tragic component of these songs and, thereby, assessing their pedagogical potential as a transformative educational resource.
Findings
The results obtained show a considerable presence of death and tragedy (19.78%) and a variety of tragedy dimensions. CFSs have been transmitted orally not only as a ludic resource, but also to prepare children for life (and death). The results show the complementarity of both analyses to avoid subjectivity while considering the underlying meanings of the songs.
Originality/value
This task had previously not been approached in an automated manner in the literature, nor there had been a similar study with a sample of this magnitude. The outcomes obtained show the considerable presence of tragedy in Spanish CFSs and emphasize the interest of this currently undervalued didactic resource.
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Faris Elghaish, Saeed Talebi, Essam Abdellatef, Sandra T. Matarneh, M. Reza Hosseini, Song Wu, Mohammad Mayouf, Aso Hajirasouli and The-Quan Nguyen
This paper aims to Test the capabilities/accuracies of four deep learning pre trained convolutional neural network (CNN) models to detect and classify types of highway cracks, as…
Abstract
Purpose
This paper aims to Test the capabilities/accuracies of four deep learning pre trained convolutional neural network (CNN) models to detect and classify types of highway cracks, as well as developing a new CNN model to maximize the accuracy at different learning rates.
Design/methodology/approach
A sample of 4,663 images of highway cracks were collected and classified into three categories of cracks, namely, “vertical cracks,” “horizontal and vertical cracks” and “diagonal cracks,” subsequently, using “Matlab” to classify the sample to training (70%) and testing (30%) to apply the four deep learning CNN models and compute their accuracies. After that, developing a new deep learning CNN model to maximize the accuracy of detecting and classifying highway cracks and testing the accuracy using three optimization algorithms at different learning rates.
Findings
The accuracies result of the four deep learning pre-trained models are above the averages between top-1 and top-5 and the accuracy of classifying and detecting the samples exceeded the top-5 accuracy for the pre-trained AlexNet model around 3% and by 0.2% for the GoogleNet model. The accurate model here is the GoogleNet model as the accuracy is 89.08% and it is higher than AlexNet by 1.26%. While the computed accuracy for the new created deep learning CNN model exceeded all pre-trained models by achieving 97.62% at a learning rate of 0.001 using Adam’s optimization algorithm.
Practical implications
The created deep learning CNN model will enable users (e.g. highway agencies) to scan a long highway and detect types of cracks accurately in a very short time compared to traditional approaches.
Originality/value
A new deep learning CNN-based highway cracks detection was developed based on testing four pre-trained CNN models and analyze the capabilities of each model to maximize the accuracy of the proposed CNN.
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Quan Lu, Bixuan Song, Jing Chen, Iris Xie and Yutian Shen
This study aims to explore the gap between information needs and services for autism in China.
Abstract
Purpose
This study aims to explore the gap between information needs and services for autism in China.
Design/methodology/approach
The gap is revealed by investigating the status quo of autism information needs and services. The authors extracted categories and subcategories of information needs through content analysis of academic documents and then supplemented the subcategories through text mining of an online forum. Meanwhile, categories and subcategories of information services were extracted through content analysis of autism websites. Finally, the authors matched the two to explore the gap and designed a quantitative index to measure it.
Findings
A total of eight and ten categories of information needs and services are extracted, respectively. In total, six categories of information needs can be partly matched, but nearly half of the subcategories failed. Huge gaps in economic support, sociality and policy mechanisms categories are observed through the quantitative index and medium gaps in social resource services and employment categories while almost no gaps in psychological/emotional counseling, rehabilitation skills training and professional knowledge/information categories.
Originality/value
This study takes a deep insight into the gap between autism information needs and services in China, providing evidences and suggestions for information providers to improve their services. Academic documents and online forum data are adopted to avoid the impact of stigmatization, which provides a multi-source data analysis approach for the information needs of special groups.
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Anabel Quan-Haase, Andrew D. Nevin and Veronika Lukacs
Social media are central to the creation and maintenance of social relations, including romantic relations. While much of the scholarship has examined how social media play a role…
Abstract
Social media are central to the creation and maintenance of social relations, including romantic relations. While much of the scholarship has examined how social media play a role in the initiation and maintenance of romantic relations, little is known about their role in romantic dissolution. This chapter fills this gap by examining the kinds of strategies young adults employ to cope with the aftermath of a romantic breakup complicated by Facebook. Based on qualitative analysis of 10 interviews with young adults, the authors propose a typology of Facebook coping strategies for romantic breakups. The typology includes seven types of coping strategies with 12 subtopics and 25 specific actions linked to the subtopics. The authors find that those coping with a breakup engage in erasing and avoiding breakup reminders and digital traces, as they perceive them as hurtful. They regulate their use of Facebook and limit Facebook communication with the ex. An important coping strategy used was to express their emotions via Facebook content, often aimed at the ex-partner. They also use Facebook to seek support and new information about the ex, including about potential new romantic interests. Others preferred to avoid information about the ex and either deleted the ex and their friends or chose to unsubscribe to updates. Coping strategies included preventative measures such as changing passwords, blocking the ex, and adjusting privacy settings. We found our participants engaged in both goal-directed and emotionally based coping strategies. Yet, the findings suggest a tendency to rely more extensively on goal-directed coping strategies by actively addressing the breakup stressor. We also note that coping strategies specific to Facebook are more likely to be used than traditional offline forms of coping. This exploratory study serves as a starting point to better understand the role that Facebook plays in mediating online behaviors following a romantic dissolution, such that these strategies can be subsequently evaluated in terms of usefulness in clinical coping recommendations.