A capsule-based collision detection approach of irregular objects in virtual maintenance

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yuxue Jin ◽  
Jie Geng ◽  
Zhiyi He ◽  
Chuan Lv ◽  
Tingdi Zhao
Keyword(s):  
Collision Detection ◽  
Design Problems ◽  
Content Type ◽  
Detection Approach ◽  
Secondary Stage ◽  
Bounding Boxes ◽  
Two Stages ◽  
Maintenance Personnel ◽  
Virtual Maintenance ◽  
Encapsulation Methods

Purpose Virtual maintenance simulation is of great importance to help designers find and avoid design problems. During its simulation phase, besides the high precision requirement, collision detection must be suitable for all irregular objects in a virtual maintenance environment. Therefore, in this paper, a collision detection approach is proposed based on encapsulation for irregular objects in the virtual maintenance environment. Design/methodology/approach First, virtual maintenance simulation characteristics and several commonly used bounding boxes methods are analyzed, which motivates the application of encapsulation theory. Based on these, three different encapsulation methods are oriented to the needs of simulation, including encapsulation of rigid maintenance objects, flexible maintenance objects and maintenance personnel. In addition, to detecting collisions accurately, this paper divides the detection process into two stages. That is, in the first stage, a rough detection is carried out and then a tiny slice space is constructed to generate corresponding capsule groups, which will be redetected in the secondary stage. At last, several case studies are applied to illustrate the performance of the methodology. Findings The automatic construction algorithm for bounding boxes can be adapted to all forms of objects. The number of detection primitives are greatly reduced. It introduces the reachable space of the human body in maintainability as the collision search area. Originality/value The advantages of virtual maintenance simulation could also be advantageous in the industry with further studies. The paper believes this study is of particular interest to the readers of your journal.

Deformation similarity clustering based collision detection in clothing simulation

2014 ◽  
Vol 26 (5) ◽  
pp. 395-411
Author(s):  
Liu Jiongzhou ◽  
Li Jituo ◽  
Lu Guodong
Keyword(s):  
Parallel Computation ◽  
Collision Detection ◽  
Detection Efficiency ◽  
Detection Algorithm ◽  
Human Model ◽  
Content Type ◽  
High Efficient ◽  
On Line ◽  
Two Stages ◽  
Garment Design

Purpose – The 3D dynamic clothing simulation is widely used in computer-added garment design. Collision detection and response are the essential component and also the efficiency bottleneck in the simulation. The purpose of this paper is to propose a high efficient collision detection algorithm for 3D clothing-human dynamic simulation to achieve both real-time and virtually real simulation effects. Design/methodology/approach – The authors approach utilizes the offline data learning results to simplify the online collision detection complexity. The approach includes two stages. In the off-line stage, model triangles with most similar deformations are first, partitioned into several near-rigid-clusters. Clusters from the clothing model and the human model are matched as pairs according to the fact that they hold the potential to intersect. For each cluster, a hierarchical bounding box tree is then constructed. In the on-line stage, collision detection is checked and treated parallelly inside each cluster pairs. A multiple task allocation strategy is proposed in parallel computation to ensure efficiency. Findings – Reasonably partitioning the 3D clothing and human model surfaces into several clusters and implementing collision detection on these cluster pairs can efficiently reduce the model primitive amounts that need be detected, consequently both improving the detection efficiency and remaining the simulation virtual effect. Originality/value – The current methods only utilize the dynamic clothing-human status; the authors algorithm furthermore combines the intrinsic correspondence relationship between clothing and human clusters to efficiently shrink the detection query scope to accelerate the detection speed. Moreover, partitioning the model into several independent clusters as detection units is much more profitable for parallel computation than current methods those treat the model entirety as the unit.

Identifying the best practices in green operations strategy of hospitals

2019 ◽  
Vol 26 (4) ◽  
pp. 1106-1131 ◽  
Author(s):  
Yazan Khalid Abed-Allah Migdadi ◽  
Abeer Ahmad Omari
Keyword(s):  
Best Practices ◽  
Waste Management ◽  
Electrical Power ◽  
Global Reporting Initiative ◽  
Operations Strategy ◽  
Content Type ◽  
Hazardous Waste Management ◽  
The World ◽  
Sustainability Reports ◽  
Two Stages

Purpose The purpose of this paper is to identify the best practices in the green operations strategy of hospitals. Design/methodology/approach A total of 25 cases from all over the world were investigated. The source of data was the annual sustainability reports that were retrieved from Global Reporting Initiative (GRI) database. The present research adopted the benchmarking method and the quantitative content analysis of sustainability reports. Then, the indicative models of best practices were developed by using two analysis approaches; within cluster analysis and across clusters analysis. Findings This study found four major taxonomies of green operation strategy in hospitals. The significant strategic groups were resources/waste management; electrical power management; non-hazardous waste management; and emissions/resources management. Indicative models for the relationship between actions and key green performance indicators were developed in the two stages of the analysis. Originality/value The best practices of green operations strategies in hospitals have not so far been investigated. Countries around the world should obey the new regulations for their environmental footprint; if they do, it will exert pressure on all sectors and organizations at all levels to take immediate steps to measure and improve their environmental performance.

Collision-Free Tool Path Generation for Five-Axis High Speed Machining

2011 ◽  
Vol 474-476 ◽  
pp. 961-966 ◽  
Author(s):  
Li Qiang Zhang ◽  
Min Yue
Keyword(s):  
Image Analysis ◽  
Collision Detection ◽  
High Speed ◽  
Tool Path ◽  
Geometric Model ◽  
High Speed Machining ◽  
Analysis Method ◽  
Geometric Information ◽  
Detection Approach ◽  
Five Axis

Collision detection is a critical problem in five-axis high speed machining. Using a combination of process simulation and collision detection based on image analysis, a rapid detection approach is developed. The geometric model provides the cut geometry for the collision detection and records a dynamic geometric information for in-process workpiece. For the precise collision detection, a strategy of image analysis method is developed in order to make the approach efficient and maintian a high detection precision. An example of five-axis machining propeller is studied to demonstrate the proposed approach. It has shown that the collision detection task can be achieved with a near real-time performance.

Tool workspace consideration for assembly plan generation

2021 ◽  
Vol 41 (5) ◽  
pp. 612-625
Author(s):  
Akram Bedeoui ◽  
Riadh Ben Hadj ◽  
Moncef Hammadi ◽  
Nizar Aifaoui
Keyword(s):  
Collision Detection ◽  
New Product ◽  
Production Costs ◽  
Assembly Sequence ◽  
Content Type ◽  
Plan Generation ◽  
Assembly Sequences ◽  
Dynamic Interference ◽  
Time Decrease

Purpose During the design of a new product, the generation of assembly sequences plans (ASPs) has become one of the most important problems taken into account by researchers. In fact, a good mounting order allows the time decrease of the assembly process which leads to the reduction of production costs. In this context, researchers developed several methods to generate and optimize ASP based on various criteria. Although this paper aims to improve the quality of ASP it is necessary to increase the number of criteria which must be taken into account when generating ASPs. Design/methodology/approach In this paper, an ASP generation approach, which is based on three main algorithms, is proposed. The first one generates a set of assembly sequences based on stability criteria. The obtained results are treated by the second algorithm which is based on assembly tools (ATs) workspace criterion. An illustrative example is used to explain the different steps of this proposed approach. Moreover, a comparative study is done to highlight its advantages. Findings The proposed algorithm verifies, for each assembly sequence, the minimal required workspace of used AT and eliminates the ASPs non-respecting this criterion. Finally, the remaining assembly sequences are treated by the third algorithm to reduce the AT change during the mounting operation. Originality/value The proposed approach introduces the concept of AT workspace to simulate and select ASPs that respect this criterion. The dynamic interference process allows the eventual collision detection between tool and component and avoids it. The proposed approach reduces the AT change during the mounting operations.

Efficient common objects localization based on deep hybrid Siamese network

2021 ◽  
pp. 1-10
Author(s):  
Mona M. Moussa ◽  
Rasha Shoitan ◽  
Mohamed S. Abdallah
Keyword(s):  
Distance Matrix ◽  
Multiple Objects ◽  
Siamese Network ◽  
Generation Stage ◽  
Pascal Voc ◽  
The Common ◽  
Conventional Methods ◽  
Weakly Supervised ◽  
Bounding Boxes ◽  
Two Stages

Finding the common objects in a set of images is considered one of the recent challenges in different computer vision tasks. Most of the conventional methods have proposed unsupervised and weakly supervised co-localization methods to find the common objects; however, these methods require producing a huge amount of region proposals. This paper tackles this problem by exploiting supervised learning benefits to localize the common object in a set of unlabeled images containing multiple objects or with no common objects. Two stages are proposed to localize the common objects: the candidate box generation stage and the matching and clustering stage. In the candidate box generation stage, the objects are localized and surrounded by the bounding boxes. The matching and clustering stage is applied on the generated bounding boxes and creates a distance matrix based on a trained Siamese network to reflect the matching percentage. Hierarchical clustering uses the generated distance matrix to find the common objects and create clusters for each one. The proposed method is trained on PASCAL VOC 2007 dataset; on the other hand, it is assessed by applying different experiments on PASCAL VOC 2007 6×2 and Object Discovery datasets, respectively. The results reveal that the proposed method outperforms the conventional methods by 8% to 40% in terms of corloc metric.

The first two decades of Circular Economy in the 21st century: a bibliographic review

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
João Francisco Pinto Anaruma ◽  
Jorge Henrique Caldeira de Oliveira ◽  
Francisco Anaruma Filho ◽  
Wesley Ricardo de Souza Freitas ◽  
Adriano Alves Teixeira
Keyword(s):  
21St Century ◽  
Circular Economy ◽  
Review Of Literature ◽  
Content Type ◽  
Time Period ◽  
Number Of Publications ◽  
Two Stages ◽  
Academic Area ◽  
Practical Implications ◽  
Made In

PurposeThe purpose of this paper is to analyze and map the main areas of the Circular Economy literature of the first two decades of 21st century, offering a broad vision about the growth of the theme during these years.Design/methodology/approachThe research was divided into two stages: the first was a systematic review of literature and the second consisted on generation and analysis of bibliographic maps.FindingsThe publication indicates the prominence of China and European Union countries in the production of articles about Circular Economy. Furthermore, the topic is restricted to academic area, and that research on Circular Economy is still very focused on theory studies, even with exponential growth in the number of published articles about the theme since 2015. Finally, it also provides a collection of information as the principal authors, the most cited publications, citations, co-citations and countries that have most published beyond which are the most discussed topics.Research limitations/implicationsA possible limitation of the research is that it was performed only in the Scopus database. It may be suggested as future searches that other databases are included as well, and another suggestion is to reduce the time period between research samples due to the exponential increase in the number of publications and topics discussed lately.Practical implicationsThe results of this paper can guide future researches about the development of Circular Economy during the next decades or years and serve as a facilitator for researchers and for managers that want to know more about the topic.Originality/valueA mapping of the principal players and main discussions about Circular Economy made in the first two decades of the 21st century and an analysis about the growth and changes about the theme.

Two facets of pride and knowledge hiding: an empirical analysis

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Myat Su Han ◽  
Daniel Peter Hampson ◽  
Yonggui Wang
Keyword(s):  
Self Efficacy ◽  
Moral Emotions ◽  
Design Strategies ◽  
Content Type ◽  
Adverse Experiences ◽  
Hiding Behavior ◽  
Recruitment And Selection ◽  
Two Stages ◽  
Knowledge Hiding ◽  
Authentic Pride

Purpose This study aims to investigate whether or not the two facets of pride, hubristic and authentic, are associated with knowledge hiding. Design/methodology/approach This study collects survey data (N = 343) from one of the leading information technology (IT) companies in Myanmar at two stages with a two-month interval. This study uses multiple regression analyses to test this study’s hypotheses. Findings Results reveal that hubristic pride is positively related to knowledge hiding, whereas the relationship between authentic pride and knowledge hiding is negative. These relationships are contingent upon the level of employees’ self-efficacy. Research limitations/implications This study suggests that managers should include measures for moral emotions in their recruitment and selection criteria. Furthermore, the authors suggest that managers should design strategies to induce moral emotions at the workplace and enhance personal resources (e.g. self-efficacy), which have an instrumental effect in maximizing the prosocial facet of pride (i.e. authentic pride) as well as minimizing adverse experiences of the antisocial facet of pride (i.e. hubristic pride), thereby reducing knowledge hiding. Originality/value The findings shed light on the significance of the inclusion of emotional variables in understanding employees’ knowledge hiding. To the best of the authors’ knowledge, this study is the first empirical study to examine the combined effect of emotive and cognitive variables in predicting knowledge hiding by demonstrating that hubristic pride only mitigates knowledge hiding behavior among high self-efficacious employees.

Intellectual capital and performance of listed companies: empirical evidence from Italy

2014 ◽  
Vol 18 (1) ◽  
pp. 22-35 ◽  
Author(s):  
Domenico Celenza ◽  
Fabrizio Rossi
Keyword(s):  
Explanatory Power ◽  
Value Added ◽  
Listed Companies ◽  
Cross Sectional ◽  
Content Type ◽  
Accounting Performance ◽  
And Performance ◽  
The One ◽  
Two Stages ◽  
The Relationship

Purpose – The aim of this paper is to investigate the relationship between corporate performance and Value Added Intellectual Coefficient (VAICTM) on the one hand, and the relationship between the variations in market value and the variations in VAIC on the other hand. Design/methodology/approach – Starting from the VAIC model, 23 Italian listed companies were examined with the aim of investigating the relationship between VAIC and the performance of the firms in the sample. The analysis was divided into two stages. In the first stage, eight models of linear regression were estimated to verify the presence of a positive and statistically significant relationship between M/BV and VAIC and between accounting performance indicators (ROE, ROI, ROS) and the VAIC. In the second stage, six other models were tested, considering as an independent variable the variations in VAIC and the variations in profitability indicators. Findings – The outcomes of the application stress the importance of VAIC in the explanation of the variations in MV and its role as “additional coefficient” in the analysis of equity performance. Originality/value – This methodology highlights some very interesting aspects. In particular, whereas the relationship between M/BV and VAIC and between profitability indicators (ROI, ROE, ROS) and VAIC is statistically insignificant, the subsequent analysis highlights the importance of VAIC as a variable capable of increasing the explanatory power of the regression in a cross-sectional perspective.

Comparison of diffused layer prepared using liquid dopant solutions and pastes for solar cell with screen printed electrodes

2016 ◽  
Vol 33 (3) ◽  
pp. 167-171 ◽  
Author(s):  
Kazimierz Drabczyk ◽  
Edyta Wróbel ◽  
Grazyna Kulesza-Matlak ◽  
Wojciech Filipowski ◽  
Krzysztof Waczynski ◽  
...  
Keyword(s):  
Solar Cells ◽  
Ethyl Alcohol ◽  
Diffusion Processes ◽  
Phosphorus Oxychloride ◽  
Low Cost ◽  
Content Type ◽  
Base Solution ◽  
Different Types ◽  
Main Components ◽  
Two Stages

Purpose The purpose of this study is comparison of the diffusion processes performed using the commercial available dopant paste made by Filmtronics and the original prepared liquid dopant solution. To decrease prices of industrially produced silicon-based solar cells, the new low-cost production processes are necessary. The main components of most popular silicon solar cells are with diffused emitter layer, passivation, anti-reflective layers and metal electrodes. This type of cells is prepared usually using phosphorus oxychloride diffusion source and metal pastes for screen printing. The diffusion process in diffusion furnace with quartz tube is slow, complicated and requires expensive equipment. The alternative for this technology is very fast in-line processing using the belt furnaces as an equipment. This approach requires different dopant sources. Design/methodology/approach In this work, the diffusion processes were made for two different types of dopant sources. The first one was the commercial available dopant paste from Filmtronics and the second one was the original prepared liquid dopant solution. The investigation was focused on dopant sources fabrication and diffusion processes. The doping solution was made in two stages. In the first stage, a base solution (without dopants) was made: dropwise deionized (DI) water and ethyl alcohol were added to a solution consisting of tetraethoxysilane (TEOS) and 99.8 per cent ethyl alcohol. Next, to the base solution, orthophosphoric acid dissolved in ethyl alcohol was added. Findings Diffused emitter layers with sheet resistance around 60 Ω/sq were produced on solar grade monocrystalline silicon wafers using two types of dopant sources. Originality/value In this work, the diffusion processes were made for two different types of dopant sources. The first one was the commercial available dopant paste from Filmtronics and the second one was the original prepared liquid dopant solution.

Modeling bid/no bid decisions using fuzzy fault tree

2018 ◽  
Vol 18 (1) ◽  
pp. 90-108 ◽  
Author(s):  
Mohamed Marzouk ◽  
Emad Mohamed
Keyword(s):  
Fault Tree ◽  
The Body ◽  
Final Decision ◽  
Extensive Literature ◽  
Willingness To Participate ◽  
Tree Model ◽  
Content Type ◽  
Proposed Model ◽  
Multiple Experts ◽  
Two Stages

Purpose Decisions by construction contractors to bid (or not to bid) require the thorough assessment and evaluation of factors relevant to the decision, as well as the quantification of their combined impact, to produce successful bid/no-bid decisions. The purpose of this study is to present a fuzzy fault tree model to assist construction contractors to more efficiently bid for future projects. Design/methodology/Approach The proposed model consist of two stages: first, identification of the factors that affect bidding decision using a questionnaire survey after an extensive literature review, and second, usage of the identified factors to build a fuzzy fault tree model to simulate the bidding decision. Findings A list of 15 factors that affect bid/no-bid decisions was identified. Analysis of factors revealed that the highest-ranking factors were related to financial aspects of the project. A case study is presented to demonstrate the capabilities of the model, and a fuzzy important analysis is performed on the basic events to demonstrate the differences between three contractors’ bid/no-bid decisions. The results reveal that there is variation between the decisions of each contractor based on their willingness to participate. Besides, the influence of evaluation factors on the final decision for each contractor is different. Originality/value The study contributes to the body of knowledge on tendering and bidding practices. The proposed model incorporated the fuzzy set theory, which suits human subjectivity. The proposed methodology overcomes the limitations of previous models as it can, using the linear pool opinion principle, combine and weigh the evaluations of multiple experts. In addition, the model is convenient for situations where historical data are not available.

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