An automatic approach to constrained quadrilateral mesh generation

2019 ◽  
Vol 37 (3) ◽  
pp. 929-951 ◽  
Author(s):  
Xinwu Ma ◽  
Lu Sun
Keyword(s):  
Laplace Equation ◽  
Mesh Generation ◽  
Design Methodology ◽  
User Interaction ◽  
Mesh Size ◽  
Quadrilateral Mesh ◽  
Content Type ◽  
Internal Feature ◽  
Required Quality ◽  
Feature Constraints

Purpose Arbitrary constraints might be included into the problem domain in many engineering applications, which represent specific features such as multi-domain interfaces, cracks with small yield stresses, stiffeners attached on the plate for reinforcement and so on. To imprint these constraints into the final mesh, additional techniques need to be developed to treat these constraints properly. Design/methodology/approach This paper proposes an automatic approach to generate quadrilateral meshes for the geometric models with complex feature constraints. Firstly, the region is decomposed into sub-regions by the constraints, and then the quadrilateral mesh is generated in each sub-region that satisfies the constraints. A method that deals with constraint lines and points is presented. A distribution function is proposed to represent the distribution of mesh size over the region by using the Laplace equation. The density lines and points can be specified inside the region and reasonable mesh size distribution can be obtained by solving the Laplace equation. Findings An automatic method to define sub-regions is presented, and the user interaction can be avoided. An algorithm for constructing loops from constraint lines is proposed, which can deal with the randomly distributed constraint lines in a general way. A method is developed to deal with constraint points and quality elements can be generated around constraint points. A function defining the distribution of mesh size is put forward. The examples of constrained quadrilateral mesh generation in actual engineering analysis are presented to show the performance of the approach. Originality/value An automatic approach to constrained quadrilateral mesh generation is presented in this paper. It can generate required quality meshes for special applications with complex internal feature constraints.

A fast algorithm for the adaptive discretization of 3D parametric curves

2019 ◽  
Vol 37 (5) ◽  
pp. 1663-1682
Author(s):  
Jianming Zhang ◽  
Chuanming Ju ◽  
Baotao Chi
Keyword(s):  
Mesh Generation ◽  
Fast Algorithm ◽  
Design Methodology ◽  
Three Dimensional ◽  
Parametric Curves ◽  
Content Type ◽  
Gaussian Integration ◽  
Optimal Discretization ◽  
Adaptive Discretization ◽  
Conventional Algorithm

Purpose The purpose of this paper is to present a fast algorithm for the adaptive discretization of three-dimensional parametric curves. Design/methodology/approach The proposed algorithm computes the parametric increments of all segments to obtain the parametric coordinates of all discrete nodes. This process is recursively applied until the optimal discretization of curves is obtained. The parametric increment of a segment is inversely proportional to the number of sub-segments, which can be subdivided, and the sum of parametric increments of all segments is constant. Thus, a new expression for parametric increment of a segment can be obtained. In addition, the number of sub-segments, which a segment can be subdivided is calculated approximately, thus avoiding Gaussian integration. Findings The proposed method can use less CPU time to perform the optimal discretization of three-dimensional curves. The results of curves discretization can also meet requirements for mesh generation used in the preprocessing of numerical simulation. Originality/value Several numerical examples presented have verified the robustness and efficiency of the proposed algorithm. Compared with the conventional algorithm, the more complex the model, the more time the algorithm saves in the process of curve discretization.

A model for ranking entity attributes using DBpedia

2014 ◽  
Vol 66 (5) ◽  
pp. 473-493 ◽  
Author(s):  
Fahad Alahmari ◽  
James A. Thom ◽  
Liam Magee
Keyword(s):  
Design Methodology ◽  
User Study ◽  
User Interaction ◽  
Attribute Importance ◽  
Content Type ◽  
Entity Search ◽  
Semantic Data ◽  
Proposed Model ◽  
Web Of Data ◽  
Aggregated Search

Purpose – Previous work highlights two key challenges in searching for information about individual entities (such as persons, places and organisations) over semantic data: query ambiguity and redundant attributes. The purpose of this paper is to consider these challenges and proposes the Attribute Importance Model (AIM) for clustering and ranking aggregated entity search to improve the overall users’ experience of finding and navigating entities over the Web of Data. Design/methodology/approach – The proposed model describes three distinct techniques for augmenting semantic search: first, presenting entity type-based query suggestions; second, clustering aggregated attributes; and third, ranking attributes based on their importance to a given query. To evaluate the model, 36 subjects were recruited to experience entity search with and without AIM. Findings – The experimental results show that the model achieves significant improvements over the default method of semantic aggregated search provided by Sig.ma, a leading entity search and navigation tool. Originality/value – This proposal develops more informative views for aggregated entity search and exploration to enhance users’ understanding of semantic data. The user study is the first to evaluate user interaction with Sig.ma's search capabilities in a systematic way.

Automatic Geometry Adaptive Quadrilateral Mesh Generation Using Medial Axis Transform

2001 ◽  
Author(s):  
W. R. Quadros ◽  
K. Ramaswami ◽  
F. B. Prinz ◽  
B. Gurumoorthy
Keyword(s):  
Mesh Generation ◽  
Medial Axis ◽  
Mesh Size ◽  
Geometric Feature ◽  
Medial Axis Transform ◽  
Feature Size ◽  
Quadrilateral Mesh ◽  
Advancing Front ◽  
Radius Function

Abstract The medial axis transform (MAT) has been used in meshing algorithms for decomposition (Tam 1991; Price 1995; Price 1997) and for decomposition and termination (Quadros 2000: Quadros Thesis 2000). This paper describes an algorithm that uses the MAT for quad meshing that is adapted to the variation of geometric feature size in the domain. The algorithm is a modification of Lay Tracks, an automatic quad meshing algorithm that uses the MAT for both subdividing the domain and for terminating the advancing front of the mesh. The modification involves the adaptive placing of nodes inside the subdivided regions and makes use of the radius function available in the MAT to identify feature size and adapt the node spacing and mesh size to it. The algorithm has been implemented and tested on some typical geometries. Results on the quality of the mesh obtained are presented.

Beyond “Likes”

2018 ◽  
Vol 39 (1/2) ◽  
pp. 59-65 ◽  
Author(s):  
Janice Peñaflor
Keyword(s):  
Best Practices ◽  
Academic Libraries ◽  
Design Methodology ◽  
User Interaction ◽  
The Philippines ◽  
Target Audience ◽  
User Engagement ◽  
University Libraries ◽  
Content Type ◽  
Facebook Pages

Purpose The purpose of this paper is to examine the performance of the academic libraries’ Facebook pages in relation to the type of content they provide and the user engagement they generate. Design/methodology/approach Facebook pages of ten university libraries in the Philippines were analyzed for their posts and user interaction to look at their effectiveness in driving engagement with their target audience. Findings This study reveals that engagement is low for majority of libraries. For the most part, frequency of posts is directly proportional to the engagement rate. Photo posts and events-related posts account for the bulk of status posts and gather a higher level of interaction than any other type of postings. Status posts that are non-library related are also receiving a considerable engagement rate. Research limitations/implications Because of the absence of the Facebook Insights data, only the information publicly available from the Facebook pages of the libraries were utilized for this study. The findings of this research will help libraries to effectively create a plan of action to further build community and increase interaction in their Facebook sites. The results may also provide useful data for best practices and establish benchmark by which other libraries could evaluate their own performance. Originality/value While majority of the studies conducted analyze the type content posted by libraries in their Facebook pages, this study provides further investigation by looking at the engagement level generated by these posts as a primary gauge for determining the effectiveness of the libraries in creating engagement amongst their audience.

Presentation of spatial information in navigation aids for the visually impaired

2015 ◽  
Vol 9 (3) ◽  
pp. 174-181 ◽  
Author(s):  
Daniel Innala Ahlmark ◽  
Kalevi Hyyppä
Keyword(s):  
Visual Impairment ◽  
Interaction Design ◽  
Visually Impaired ◽  
Design Methodology ◽  
Spatial Information ◽  
Spatial Perception ◽  
User Interaction ◽  
Information Presentation ◽  
Content Type ◽  
Visual Spatial

Purpose – The purpose of this paper is to present some guidelines on how different means of information presentation can be used when conveying spatial information non-visually. The aim is to further the understanding of the qualities navigation aids for visually impaired individuals should possess. Design/methodology/approach – A background in non-visual spatial perception is provided, and existing commercial and non-commercial navigation aids are examined from a user interaction perspective, based on how individuals with a visual impairment perceive and understand space. Findings – The discussions on non-visual spatial perception and navigation aids lead to some user interaction design suggestions. Originality/value – This paper examines navigation aids from the perspective of non-visual spatial perception. The presented design suggestions can serve as basic guidelines for the design of such solutions.

Public libraries on Facebook: content analysis of Turkish public libraries' posts

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tolga Çakmak ◽  
Şahika Eroğlu
Keyword(s):  
Young Adults ◽  
Content Analysis ◽  
Design Methodology ◽  
Latent Dirichlet Allocation ◽  
Public Libraries ◽  
User Interaction ◽  
Content Type ◽  
Content Analyses ◽  
General Topic ◽  
Facebook Pages

PurposeThe study aims to analyze the posts shared by public libraries in Turkey on their official Facebook pages. The targets of the study are to detect content categories shared by the libraries and to describe user interaction of libraries on the basis of their posted content.Design/methodology/approachThe study examined data relating to 23,027 posts shared by 116 public libraries through descriptive and content analyses. The content analysis on the posts identified general topic and sub-topics through both machine-tagging and checks by the authors. Turkish word parsing applications and stop lists were employed in the designation of sub-categories. In this process, word clusters were identified to allow for the designation of sub-topic headings through the use of the Latent Dirichlet Allocation (LDA) technique.FindingsThe present study identified that a significant portion of the 116 public libraries in Turkey with official Facebook pages had started to use this platform in the year 2017. According to the findings, the user interaction of libraries generally occurs in the form of likes. Analyses on the topic categories of the posts established that a remarkable number of public libraries in Turkey targeted users from pre-school children to young adults.Originality/valueThe study contributes to the existing body of literature as one of the first research studies describing the current situation concerning public libraries in Turkey through the analysis of the content they generate on Facebook pages.

scholarly journals Vulnerable adults in police custody

2019 ◽  
Vol 22 (1) ◽  
pp. 5-8
Author(s):  
Ian Cummins
Keyword(s):  
Design Methodology ◽  
Research Literature ◽  
Police Custody ◽  
England And Wales ◽  
Content Type ◽  
Increased Risk ◽  
Vulnerable Adults

Purpose The purpose of this paper is to discuss the recent National Appropriate Adult Network (NAAN) report on the role of the appropriate adult. Design/methodology/approach This paper is based on the NAAN report and a review of relevant policy and research literature. Findings There to Help 2 highlights that there are still significant gaps in the provision of appropriate adult schemes across England and Wales. These gaps potentially place vulnerable adults at increased risk. Originality/value This paper is a review of recent research.

Co-workers’ perceptions of and reactions to employee’s involuntary demotion

2019 ◽  
Vol 41 (4) ◽  
pp. 740-757 ◽  
Author(s):  
Sophie Hennekam ◽  
Subramaniam Ananthram ◽  
Steve McKenna
Keyword(s):  
Design Methodology ◽  
Emotional Responses ◽  
Emotional Reaction ◽  
Content Type ◽  
Informational Justice ◽  
Behavioural Responses ◽  
Behavioural Reaction ◽  
Three Stages ◽  
Depth Interviews ◽  
The Way

Purpose The purpose of this paper is to investigate how individuals perceive and react to the involuntary demotion of a co-worker in their organisation. Design/methodology/approach The authors draw on 46 semi-structured in-depth interviews (23 dyads) with co-workers of demoted individuals. Findings The findings suggest that an individual’s observation of the demotion of a co-worker has three stages: their perception of fairness, their emotional reaction and their behavioural reaction. The perception of fairness concerned issues of distributive, procedural, interpersonal and informational justice. The emotional responses identified were feelings of disappointment/disillusion, uncertainty, vulnerability and anger. Finally, the behavioural reactions triggered by their emotional responses included expressions of voice, loyalty, exit and adaptation. Originality/value Perceptions of (in)justice perpetrated on others stimulate emotional and behavioural responses, which impacts organisational functioning. Managers should therefore pay attention to the way a demotion is perceived, not only by those directly concerned, but also by co-workers as observers.

Consumer value creation through WhatsApp use

2019 ◽  
Vol 32 (4) ◽  
pp. 455-471
Author(s):  
Jorge Cruz-Cárdenas ◽  
Jorge Guadalupe-Lanas ◽  
Ekaterina Zabelina ◽  
Andrés Palacio-Fierro ◽  
Margarita Velín-Fárez ◽  
...  
Keyword(s):  
Latin American ◽  
Value Creation ◽  
Emotional Support ◽  
Design Methodology ◽  
Instant Messaging ◽  
Role Performance ◽  
Content Type ◽  
Consumer Value ◽  
Depth Interviews ◽  
Practical Implications

Purpose The purpose of this paper is to understand in-depth how consumers create value in their lives using WhatsApp, the leading mobile instant messaging (MIM) application. Design/methodology/approach The study adopts the perspective of customer-dominant logic (CDL) and uses a qualitative multimethod design involving 3 focus groups and 25 subsequent in-depth interviews. The research setting was Ecuador, a Latin American country. Findings Analysis and interpretation of the participants’ stories made it possible to identify and understand the creation of four types of value: maintaining and strengthening relationships; improving role performance; emotional support; and entertainment and fun. In addition, the present study proposes a conceptual model of consumer value creation as it applies to MIM. Practical implications Understanding the way consumers create value in their lives using MIM is important not only for organizations that offer MIM applications, but also for those companies that develop other applications for mobile phones or for those who wish to use MIM as an electronic word-of-mouth vehicle. Originality/value The current study is one of the first to address the topic of consumer behavior in the use of technologies from the perspective of CDL; this perspective enables an integrated qualitative vision of value creation in which the consumer is the protagonist.

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