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Article
Publication date: 31 May 2022

Shuo Huang, Yang Liu and Ke Li

The purpose of this paper is to compare the single-sided packaging structure and double-sided packaging structure of high-power module and study the overall heat…

Abstract

Purpose

The purpose of this paper is to compare the single-sided packaging structure and double-sided packaging structure of high-power module and study the overall heat dissipation performance and reliability of the module.

Design/methodology/approach

In this paper, the single-sided packaging structure and double-sided packaging structure of power module are designed based on Wolfspeed products. This paper is analyzed by finite element method. First, the heat dissipation performance of single-sided packaging structure and double-sided packaging structure is analyzed; second, the deformation and stress of single-sided packaging structure and double-sided packaging structure are compared and analyzed; and finally, the cumulative plastic deformation of single-sided packaging and double-sided packaging structures are compared and analyzed, and the fatigue life of the structure is calculated based on the plastic deformation.

Findings

In the heat transfer simulation, under the same power input, the heat dissipation performance of single-sided packaging structure is not as good as that of double-sided packaging structure. Under the reliability simulation of the same temperature cycle standard, the maximum equivalent stress of single-sided packaging structure is lower than that of double-sided packaging structure, but the fatigue life prediction based on plastic strain shows that the fatigue life of double-sided packaging structure is not different from that of single-sided packaging structure.

Originality/value

This paper creatively simulates the thermal characteristics and reliability of single-sided packaging structure and double-sided packaging structure and proves the advantages of double-sided packaging structure compared with single-sided packaging structure from the aspects of heat transfer performance and reliability.

Details

Soldering & Surface Mount Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0954-0911

Keywords

Book part
Publication date: 1 August 2019

Evgeniy G. Molchanov, Angelika K. Musaelyan, Ruslan G. Mikhaylenko and Elena N. Smertina

Purpose: The purpose of the chapter is to determine the dependence of the process of decision making in modern business systems on their organizational structure and to…

Abstract

Purpose: The purpose of the chapter is to determine the dependence of the process of decision making in modern business systems on their organizational structure and to substantiate the necessity for considering the requirements to the process of decision making during designing the organizational structure of a business system.

Methodology: A new simplified classification of the organizational structure of business systems according to the criterion of complexity is offered, and its two main types are distinguished – organizational structure of low complexity and organizational structure of high complexity.

Conclusions: According to the offered classification, dependence of the process of decision making in modern business systems on complexity of their business structure at each stage of making of managerial decisions is determined. As a result of analysis of statistical data, it is determined that business systems with organizational structure of low complexity dominate in Russia. By the example of modern Russian business systems with the organizational structure of high complexity – Sberbank, Lukoil, Gazprom, and Rosneft – it is shown that formation of the structure of this type and supporting its functioning requires resources and thus is inaccessible for most modern business systems. Moreover, the expected advantages, related to high probability of making of optimal managerial decisions, are not always gained in practice.

Originality/value: It is substantiated that the process of decision making in modern business systems largely depends on the complexity of their organizational structure. With increase of complexity of a business system, resource intensity of decision making and duration of this process increase, but the risk of nonoptimal decisions decreases. Organizational structure of low complexity is peculiar for business systems that have deficit of financial and human resources, which does not allow using the means of optimization and fully control the process of decision making. However, in this case, managerial decisions are made much quicker. In the conditions of modern market economy, it is necessary to make quick optimal decisions, which cannot be achieved within the organizational structure of either low or high complexity. Thus, it is necessary to find a way to make quick optimal managerial decisions beyond the design of organizational structure.

Details

Specifics of Decision Making in Modern Business Systems
Type: Book
ISBN: 978-1-78756-692-7

Keywords

Article
Publication date: 23 September 2022

Ying Yu, Huan Huang, Shuo Wang, Shuaishuai Li and Yu Wang

The mesoscale structure (MS) has a significant impact on the mechanical performance of parts made by additive manufacturing (AM). This paper aims to explore the design and…

Abstract

Purpose

The mesoscale structure (MS) has a significant impact on the mechanical performance of parts made by additive manufacturing (AM). This paper aims to explore the design and fabrication of force-flow guided reinforcement mesoscale structure (FFRMS) compared with the homogeneous mesoscale structure (HMS), which is inconsistent with the stress field for a given load condition. Some cases were presented to demonstrate the mechanical properties of FFRMS in terms of MS combined with quasi-isotropy and anisotropy.

Design/methodology/approach

The paper consists of four main sections: the first developed the concept of FFRMS design based on HMS, the second explored volume fraction control for the proportion of force-flow lines in terms of mechanical property requirement, and the third presented a sequence stacking theory and practical manufacturing process framework and the final sections provided some application case studies.

Findings

The main contributions of this study were the definition and development of the FFRMS concept, the application framework and the original case studies. As an example, a typical lug designed with the proposed FFRMS method was fabricated by three different AM processes. The test results showed that both the strength and stiffness of the specimens are improved greatly by using the FFRMS design method.

Originality/value

The superposition of HMS as the basement and force-flow as an indication of the stiffener, leading to a heterogeneous structure, which exhibits more efficient and diversified means compared with the traditional way of increasing the HMS density merely.

Details

Rapid Prototyping Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 19 September 2022

Yongtai Chen, Rui Li, En-yu Zeng and Pengfei Li

This study aims to analyze the relevance of the city spatial structure for smart city innovation from the perspective of agglomeration externalities, and discusses whether…

Abstract

Purpose

This study aims to analyze the relevance of the city spatial structure for smart city innovation from the perspective of agglomeration externalities, and discusses whether there is heterogeneity in innovation across different geographical areas and population scales of cities.

Design/methodology/approach

The authors construct the centralization and concentration indexes to conceptualize the city spatial structure of 286 cities (prefecture-level) in China based on the LandScan Global Population Dataset from 2001 to 2016. A fixed-effects panel data model is employed to analyze the relationship between the spatial structure and the innovation ability of smart cities; the results were validated through robustness tests and heterogeneity analyses.

Findings

The study found that the more concentrated and more evenly the distribution of urban population, namely the more city spatial structure tends to be weak-monocentricity, the higher the level of innovation in smart cities. The relevance of the weak-monocentricity structure and smart city innovation varies significantly depending on their geographical location and the size of the city. This result is more applicable to cities in the eastern and central regions, as well as to cities with smaller populations.

Originality/value

The adjustment and optimization of the city spatial structure is important for enhancing smart city construction. Unlike previous studies, which mostly use a single dimension of “the proportion of population in sub-centres to the population of all central areas” to measure city spatial structure, the authors employed the spatial centralization and spatial concentration. It is hoped that this study can guide smart city construction from the perspective of the development model of city spatial structure.

Details

Industrial Management & Data Systems, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0263-5577

Keywords

Article
Publication date: 14 September 2022

Apoorva Arunachal Hegde, Venkateshwarlu Masuna, Ajaya Kumar Panda and Satish Kumar

This paper aims to conduct bibliometric analysis on the studies dealing with capital structure’s speed of adjustment (SoA) and identify the prominent themes while…

Abstract

Purpose

This paper aims to conduct bibliometric analysis on the studies dealing with capital structure’s speed of adjustment (SoA) and identify the prominent themes while suggesting future research directions in the area. The existing reviews broadly focus on the capital structure, which provides the scope for conducting a review on this sub-aspect of capital structure.

Design/methodology/approach

This study uses a three-stage process to conduct this review: identification of academic journals, selection and analysis of target papers. This study uses a combination of bibliometric tools and a system thinking approach to assess the current status of publications and emerging themes within the literature.

Findings

This study has found a progressive evolution of SoA in capital structure research from 1984 to 2021. Studies largely focus on implementing the dynamic models to analyse the impact of adjustment costs, dynamic economic conditions, corporate governance practices and other variables on the firms’ adjustment speed and financial decisions. The network analysis of citations, keywords and clusters gives further knowledge on the intellectual structure of the data.

Research limitations/implications

This study is highly dependent on the papers available within the SCOPUS database. Studies not included herein are not part of this analysis, which may or may not bear an effect on the study’s findings.

Originality/value

To the best of the authors’ knowledge, the application of systems engineering concept of “system thinking approach” to identify literature gap and suggest directions for forthcoming research is the first of its kind, thus adding a novel and multidisciplinary aspect to this study.

Details

Qualitative Research in Financial Markets, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1755-4179

Keywords

Article
Publication date: 3 October 2022

Mingkang Zhang, Meizhen Xu, Jinwei Li, Wenqing Shi and Yangzhi Chen

This study aims to explore the compressive behavior of hollow triply periodic minimal surface (HTPMS) cellular structures by selective laser melting (SLM).

Abstract

Purpose

This study aims to explore the compressive behavior of hollow triply periodic minimal surface (HTPMS) cellular structures by selective laser melting (SLM).

Design/methodology/approach

This study presents a design method for gyroid hollow triply periodic minimal surfaces (G-HTPMS) and primitive hollow triply periodic minimal surfaces (P-HTPMS) cellular structures, and SLM technology was applied to manufacture these cellular structures. Compressive behaviors and energy absorption behaviors of hollow cellular structures were researched in this study.

Findings

Compared with normal gyroid triply periodic minimal surfaces (G-TPMS) and normal primitive triply periodic minimal surfaces (P-TPMS), the G-HTPMS and P-HTPMS have higher elastic modulus, plateau stress and effective energy absorption under uniaxial compression. The hollow design in HTPMS can enhance the mechanical properties and energy absorption of the cellular structure. Finite element analysis also demonstrates that the hollow design can reduce stress concentration, which improved the compressive curves from a severely fluctuating state to a relatively flat state and reduces fracture. According to compressive behaviors, G-TPMS and G-HTPMS are the bending-dominated cellular structures with strain hardening characteristics, and P-TPMS and P-HTPMS are the stretching-dominated cellular structures with strain softening characteristics.

Originality/value

This research provided a design method for HTPMS, and it was proved that the mechanical properties increased by hollow design inspired by bamboo.

Details

Rapid Prototyping Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 1 September 2022

Chenglei Qin and Chengzhi Zhang

The purpose of this paper is to explore which structures of academic articles referees would pay more attention to, what specific content referees focus on, and whether…

Abstract

Purpose

The purpose of this paper is to explore which structures of academic articles referees would pay more attention to, what specific content referees focus on, and whether the distribution of PRC is related to the citations.

Design/methodology/approach

Firstly, utilizing the feature words of section title and hierarchical attention network model (HAN) to identify the academic article structures. Secondly, analyzing the distribution of PRC in different structures according to the position information extracted by rules in PRC. Thirdly, analyzing the distribution of feature words of PRC extracted by the Chi-square test and TF-IDF in different structures. Finally, four correlation analysis methods are used to analyze whether the distribution of PRC in different structures is correlated to the citations.

Findings

The count of PRC distributed in Materials and Methods and Results section is significantly more than that in the structure of Introduction and Discussion, indicating that referees pay more attention to the Material and Methods and Results. The distribution of feature words of PRC in different structures is obviously different, which can reflect the content of referees' concern. There is no correlation between the distribution of PRC in different structures and the citations.

Research limitations/implications

Due to the differences in the way referees write peer review reports, the rules used to extract position information cannot cover all PRC.

Originality/value

The paper finds a pattern in the distribution of PRC in different academic article structures proving the long-term empirical understanding. It also provides insight into academic article writing: researchers should ensure the scientificity of methods and the reliability of results when writing academic article to obtain a high degree of recognition from referees.

Details

Aslib Journal of Information Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2050-3806

Keywords

Article
Publication date: 31 August 2022

Si Shen, Chuan Jiang, Haotian Hu, Youshu Ji and Dongbo Wang

Reorganising unstructured academic abstracts according to a certain logical structure can help scholars not only extract valid information quickly but also facilitate the…

Abstract

Purpose

Reorganising unstructured academic abstracts according to a certain logical structure can help scholars not only extract valid information quickly but also facilitate the faceted search of academic literature. This study aims to build a high-performance model for identifying of the functional structures of unstructured abstracts in the social sciences.

Design/methodology/approach

This study first investigated the structuring of abstracts in academic articles in the field of social sciences, using large-scale statistical analyses. Then, the functional structures of sentences in the abstract in a corpus of more than 3.5 million abstracts were identified from sentence classification and sequence tagging by using several models based on either machine learning or a deep learning approach, and the results were compared.

Findings

The results demonstrate that the functional structures of sentences in abstracts in social science manuscripts include the background, purpose, methods, results and conclusions. The experimental results show that the bidirectional encoder representation from transformers exhibited the best performance, the overall F1 score of which was 86.23%.

Originality/value

The data set of annotated social science abstract is generated and corresponding models are trained on the basis of the data set, both of which are available on Github (https://github.com/Academic-Abstract-Knowledge-Mining/SSCI_Abstract_Structures_Identification). Based on the optimised model, a Web application for the identification of the functional structures of abstracts and their faceted search in social sciences was constructed to enable rapid and convenient reading, organisation and fine-grained retrieval of academic abstracts.

Article
Publication date: 31 August 2022

Guoquan Zhang, Yaohui Wang, Jian He and Yi Xiong

Composite cellular structures have wide application in advanced engineering fields due to their high specific stiffness and strength. As an emerging technology, continuous…

Abstract

Purpose

Composite cellular structures have wide application in advanced engineering fields due to their high specific stiffness and strength. As an emerging technology, continuous fiber-reinforced polymer additive manufacturing provides a cost-effective solution for fabricating composite cellular structures with complex designs. However, the corresponding path planning methods are case-specific and have not considered any manufacturing constraints. This study aims to develop a generally applicable path planning method to fill the above research gap.

Design/methodology/approach

This study proposes a path planning method based on the graph theory, yielding an infill toolpath with a minimum fiber cutting frequency, printing time and total turning angle. More specifically, the cellular structure design is converted to a graph first. Then, the graph is modified to search an Eulerian path by adding an optimal set of extra edges determined through the integer linear programming method. Finally, the toolpath with minimum total turning angle is obtained with a constrained Euler path search algorithm.

Findings

The effectiveness of the proposed method is validated through the fabrication of both periodic and nonperiodic composite cellular structures, i.e. triangular unit cell-based, Voronoi diagram-based and topology optimized structures. The proposed method provides the basis for manufacturing planar thin-walled cellular structures of continuous fiber-reinforced polymer (CFRP). Moreover, the proposed method shows a notable improvement compared with the existing method. The fiber cutting frequency, printing time and total turning angle have been reduced up to 88.7%, 52.6% and 65.5%, respectively.

Originality/value

A generally applicable path planning method is developed to generate continuous toolpaths for fabricating cellular structures in CFRP-additive manufacturing, which is an emerging technology. More importantly, manufacturing constraints such as fiber cutting frequency, printing time and total turning angle of fibers are considered within the process planning for the first time.

Details

Rapid Prototyping Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 26 August 2022

TamilSalvi Mari, Jin Liew and Veronica Ng

The study aims to explore factors affecting stilt construction and the possibilities of using innovative materials and construction methods to re-establish the traditional…

Abstract

Purpose

The study aims to explore factors affecting stilt construction and the possibilities of using innovative materials and construction methods to re-establish the traditional stilt structures.

Design/methodology/approach

The study employs a qualitative research method using an in-depth interview with selected architects to document experience and insights of the architects on the challenges and possibilities of using innovative materials and construction methods to re-establish the traditional stilt structures. Purposive sampling was used to determine the respondents for the study. Architects with experience designing stilt houses in architects' architectural practice were selected to take in the study.

Findings

Study revealed that generally architects are keen on using stilt structures. Building materials and costs associated with designing and constructing stilt structures were identified as the key challenges. However, architects suggest using recycled building materials as possible solutions to encourage the construction of stilt structures in Malaysia. The architects also preferred to use hybridized recycled materials for stilt structures as hybridized materials have improved structural properties and functions. Additionally, the study identified “psychological hesitation” or “accessibility” as a factor affecting the construction of stilt buildings.

Research limitations/implications

Throughout this study, some limitations have been dealt with. The first is the limitation of sample size. Contemporary stilt architecture is not very common in Malaysia today, and not many architects have experience in designing stilt houses. Although the method of purposive sampling was used, a larger sample size could have generated a more diverse result. The second limitation is the dearth of research on contemporary stilt houses in Malaysia. As stilt construction is uncommon in Malaysia and the existing material focuses primarily on traditional Malay houses, this has been one of the major challenges. Finally, most of the literature on stilt construction is from Southeast Asia, limited or insufficient studies and literature on local stilt construction would have a greater benefit to the study.

Practical implications

The outcomes from this study would benefit the scholars who have an interest in exploring stilts construction in contemporary architecture as well as innovative construction materials and construction methods. As the study brings forth the challenges and possibilities of restoring the traditional stilt constructions, the study can be used as a reference by designers to garner a deeper understanding of the traditional stilt construction and encourage designers to focus on possible innovations for stilt construction from the aspects of materials and methods in ensuring the traditional element is present in future design and construction.

Originality/value

The study is a response to an obvious dearth body of knowledge in stilt construction in the Malaysian context. The study identifies the key challenges and possible and practical solutions. The findings of this study represent a scholastic effort that can be used as a reference by academics and scholars.

Details

Archnet-IJAR: International Journal of Architectural Research, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2631-6862

Keywords

1 – 10 of over 268000