Search results

Porosity is a commonly analyzed defect in the laser-based additive manufacturing processes owing to the enormous thermal gradient caused by repeated melting and solidification. Currently, the porosity estimation is limited to powder bed fusion. The porosity estimation needs to be explored in the laser melting deposition (LMD) process, particularly analytical models that provide cost- and time-effective solutions compared to finite element analysis. For this purpose, this study aims to formulate two mathematical models for deposited layer dimensions and corresponding porosity in the LMD process.

In this study, analytical models have been proposed. Initially, deposited layer dimensions, including layer height, width and depth, were calculated based on the operating parameters. These outputs were introduced in the second model to estimate the part porosity. The models were validated with experimental data for Ti6Al4V depositions on Ti6Al4V substrate. A calibration curve (CC) was also developed for Ti6Al4V material and characterized using X-ray computed tomography. The models were also validated with the experimental results adopted from literature. The validated models were linked with the deep neural network (DNN) for its training and testing using a total of 6,703 computations with 1,500 iterations. Here, laser power, laser scanning speed and powder feeding rate were selected inputs, whereas porosity was set as an output.

The computations indicate that owing to the simultaneous inclusion of powder particulates, the powder elements use a substantial percentage of the laser beam energy for their melting, resulting in laser beam energy attenuation and reducing thermal value at the substrate. The primary operating parameters are directly correlated with the number of layers and total height in CC. Through X-ray computed tomography analyses, the number of layers showed a straightforward correlation with mean sphericity, while a converse relation was identified with the number, mean volume and mean diameter of pores. DNN and analytical models showed 2%–3% and 7%–9% mean absolute deviations, respectively, compared to the experimental results.

This research provides a unique solution for LMD porosity estimation by linking the developed analytical computational models with artificial neural networking. The presented framework predicts the porosity in the LMD-ed parts efficiently.

This paper aims to develop efficient and simple models for thermal distribution, melt pool dimensions and controlled phase change in the laser additive manufacturing (AM) of bulk and powder particles ceramic materials.

This paper proposes new analytical models for the AM of bulk and powder bed ceramic materials. A volumetric moving heat source, along with the complete melting of bulk and powder particle materials, is taken into account. Different values of laser absorption coefficient in solid and liquid states have been used to investigate the phase transformation. Furthermore, the pores and voids dimensions are also included in the modeling. Theoretical predictions have been compared with the experimental analyses and finite element simulations in laser to silicon nitride and laser to alumina interaction. The analysis focuses on the impact of laser power and scanning speed on the melt pool width and depth evolution into the bulk substrate and powder bed.

This study shows that the powder particles exhibit a higher thermal distribution value than the bulk substrate because of voids in the powder layer. The laser beam experiences multiple reflections in the presence of porosity/voids, thus increasing the surface absorption coefficient, which becomes relevant with the increment in the pore/void dimension. A direct relationship has been found between the laser power and melt pool dimensions, while the scanning speed displayed an inverse relationship for the melt pool width and length. Larger melt dimensions were inferred in the case of laser–powder particle interaction compared with laser–bulk substrate interaction. A close correlation was found between the analytical simulations, experimental investigations and numerical simulation results within the range of 4%–8%.

This paper fulfills an identified need to develop efficient and simplified models for ceramics laser AM by taking into account different laser absorption coefficients in solid and liquid form, voids and pores dimensions and controlled phase transformation to avoid vapors and plasma formation. The limitation of the finite element simulation model is that the solution is strongly dependent on the mesh quality and accuracy directly linked to the computation efficiency and time. A finer mesh requires a longer computing time than a coarse mesh. Finite element simulations require, however, specialized skills.

The future of human society has to take into account on the one hand, the natural requirements of the society as a whole, and, on the other hand, the influences generated by economic, social, informational factors but also in relation to the environment. Therefore, the future is seen and described in relation to the need to create the conditions for achieving sustainable development goals. The unpredictable evolution and uncertainties of recent years explain the need to include in the decisions of organizations, responsibly applied approaches. In order to achieve and maintain a balance between the interests of various actors on a global scale, it is necessary to practice responsible management, which deals with both the management of current critical issues worldwide, but also in relation to the need to ensure living conditions and the prosperity of future generations. Thus, as an adequate response of companies and organizations of various types to these complex challenges is integrated as a defining element of business strategies a principle of responsible management called social responsibility. This means that, through the elaborated decisions, these companies have to find a way of treatment balanced between the fulfillment of their own financial objectives and the social obligation of the contributions of these entities to the sustainable development of the economy in which they operate. This results, in fact, in the large-scale development and implementation of the concept of corporate social responsibility (CSR). On the other hand, the functioning of all companies in the realities of the present times, characterized by volatility, uncertainty, complexity & ambiguity (VUCA) requires significant efforts and resources on their part, so that, by collecting an important and comprehensive volume of data, there is the possibility of generating reliable forecasts.

The purpose of the chapter is to study the European experience of formation of information economy.

The methodology of this chapter is based on the method of statistical analysis, which is used for calculation of direct average of the values of the indicators of European countries for each indicator of information economy, scatter (variation), and deviation of the average value of European countries from the average value among the leading countries of the world (average global value). The objects of research of the European experience of information economy’s formation are the leading countries of Europe that have the largest potential and achieved the largest progress, setting the tone for other members of the European region. The leading countries are UK, Germany, and France. The data of 2017 are used.

The results substantiate that modern Europe achieved sufficient progress in information economy’s formation, and differentiation of the level of informatization of economic systems is expressed vividly, but only in certain aspects. In general, it is possible to determine common tendencies and peculiarities based on offered conceptual model of establishment and development of information economy in European countries. This new conceptual model takes into account and reflects the existing disproportions, of which the most vivid is overestimated massive technosphere, which is not implemented to the full potential due to social problems. Against its background, sociosphere and economic sphere that are standard for modern leading countries seem to diminish. At the same time, due to the strong role of the state in economy of European countries, high effectiveness of state regulation in the process of information economy’s formation is achieved if high share of high-tech export is expressed with smaller expenditures for innovations in the ICT spheres.

It is recommended to use the offered conceptual model to study the process of formation of information economy in European countries and comparing the effectiveness of this process in other regions of the world.

This study explores the enablers of students “entrepreneurial intentions by identifying the factors that raise students” interest in embracing an entrepreneurial career.

Entrepreneurship education is increasingly attracting attention as a means of fostering entrepreneurial activity and creating a culture of innovation. Developing students' entrepreneurial intentions is critical to promote entrepreneurship. This research is built on a mixed method approach of partial least squares structural equation modelling and fuzzy-set qualitative comparative analysis.

The factors that influence students ‘entrepreneurial intentions are identified: business incubation programmes, non-reimbursable grants for entrepreneurial students, networking events to promote entrepreneurship, mentoring services, innovation labs for business idea validation and entrepreneurship courses. This knowledge can help develop effective entrepreneurship education programmes. The study also provides actionable insights for educational institutions and policymakers. It underscores the need for innovative educational platforms such as entrepreneurial bootcamps. It also highlights the value of advanced learning environments such as decision theatres to foster a culture of entrepreneurship and innovation.

The study contributes to the body of knowledge on entrepreneurship education. It highlights the need for a multidisciplinary approach to understand the factors that shape students’ entrepreneurial intentions.

The paper aims to investigate the standpoints and practices of university members from European developing countries regarding the harnessing of the intellectual capital (IC) within online academic social networks.

A questionnaire-based survey with 210 university members was conducted, with the indicators adopting prior measurement scales which were further adapted to a network framework.

The organizational policies and practices relate positively and highly significantly with the valuation of the network-based IC components. Moreover, 63 per cent of the professional and organizational competitiveness of higher education institutions is determined by the exploitation of the IC embedded in online academic networks.

All survey respondents were from the European developing countries, which may limit the general applicability of the findings. Also, the emphasis is laid solely on online academic networks.

This paper brings to the fore both the potential and the state-of-the-art in leveraging the IC of online specialized networks which are indicative of the academic field. When acknowledged as such, the network-based IC is liable to generate substantial competitive advantages at the professional and organizational levels at the same time.

This research adds to the extant literature in two main ways. First, it advances a new construct – network-based IC – in the context of the online academic social networks. Second, it proposes a research model for addressing the network-based IC from a competitive advantage perspective.

This chapter is devoted to sustainable human resource management that leads to sustainable competitiveness. It features the ways human resources can be managed to carry out sustainable goals and the impact of sustainability on employees' attitudes and behaviours. The aim of this study is to explore the complex objectives of sustainability and human resource management and empirically investigate the dynamic relationship between human resources in science and technology and sustainable competitiveness in the case of 35 European countries. Our contribution emphasizes this interrelationship and its causality. For this research, we applied a vector auto-regression (VAR) model, and the Granger causality method to examine the relationship between human resources in science and technology and sustainable competitiveness. A panel data included 314 observations between 2012 and 2021. The panel VAR for analysing the impulse response function was enriched with the 5% and 95%, using Monte Carlo simulations. The research results revealed bidirectional causality in the European countries between human resources in science and technology and sustainable competitiveness. Human resources in science and technology trigger sustainable competitiveness and vice versa. As an element of originality, our study demonstrates that human resources in science and technology contribute to sustainable performance, and, on the other hand, a more competitive and sustainable environment contributes to the development of human resources in science and technology. Thus, the chapter outlines the role of human resources in science and technology with regard to sustainable human resource management (HRM), and how to navigate these objectives so that they can positively influence sustainable competitiveness.

The purpose of this study is to recognize the empirical inhibitors of knowledge management (KM)in value co-creation in the dairy production context.

This study undertook a qualitative multiple-case study strategy. The datas collected comes from five players in the dairy sector that jointly co-create value. In addition to in-depth interviews with the actors, this study considers complementary documents, with reports, management flowcharts. Content analysis was conducted based on Bardin (2011).

This study identified three empirical barriers for KM in managing value co-creation in dairy production. The inhibitors observed were related to ineffective communication among stakeholders, organizational culture and high competitiveness. This study identified that sharing and KM among actors is a way to stimulate innovative solutions via value co-creation in dairy production.

This study explores the context in the Center-South of Brazil; therefore, it is not generalizable.

The findings help the managers to deal with the KM inhibitors in the value co-creation context and define actions based on the strategies listed to overcome the barriers identified in dairy production. This study can also help managers to change the mindset of organizations by adding KM to the organizational culture, as it identifies existing barriers in the sector and contributes by suggesting attitudes and tools capable of overcoming such difficulties.

Professionals in the dairy sector, especially the small rural producer, can have access to knowledge and professional training through the value co-creation among actors in the dairy sector. In this sense, the milk quality, for example, the nutritional characteristics and traceability of the milk, can be improved for the final consumer.

This study reveals the empirical inhibitors of KM presents in the value co-creation in the dairy production context. Additionally, insights to deal with the lack of sharing information and knowledge among multiple actors.

This paper aims to present an analysis of a hybrid high‐voltage switch based on the parallel connection of IGBT and IGCT. The proposed configuration combines the advantages of both semiconductors, resulting in substantially reduced power losses. Such energy efficient switches could be used in high‐power systems where the requirements of high switching frequency or decreased cooling systems are a major concern.

The operation principle of the switch is described and simulated. The power dissipation is estimated at different operation conditions. Further, the implementation possibilities of the proposed switch configuration in a three‐level NPC inverter are analysed. The operation with the proposed PWM control algorithm is simulated and inverter power loss distribution is estimated.

According to estimations, the proposed hybrid switch configuration allows the reduction of total losses in semiconductors by at least 50 percent. If two of these switches are used in a three‐level NPC inverter as outer switches, the total losses of the inverter are reduced by 27 percent, at the same time the losses in the most stressed semiconductor device are reduced by a factor of 2.25. Therefore, achieving higher power density is possible.

The proposed switch configuration is intended for high‐power (>500 KVA) industrial, marine and railway traction systems, such as FACTS and high power variable frequency AC drives.

The paper presents the novel energy‐efficient high‐voltage switch based on the parallel connection of commercially available IGBTs and IGCTs.

This paper aims to map the knowledge management research in small businesses and suggest future actions to strengthen managerial practices. Knowledge management practices foster the growth of small businesses. They allow innovation to grow within the institutions, enhance customer satisfaction and reduce employee absenteeism and attrition.

The study adopts a bibliometric protocol to retrieve the 686 articles published in the Web of Science (WoS) database. The WoS database is selected to ensure only quality and peer-reviewed publications are analysed in the study. It then identifies the top contributions, and existing thematic areas, and suggests future research and policy actions for boosting economic growth through small business. The study uses VOSviewer, Science of Science (Sci2) and Gephi to conduct the bibliometric and network analysis.

The results from keyword co-occurrence and co-citation analysis helps in identifying thematic areas. The findings highlight that there exist five major themes in knowledge management research for small businesses. The dynamic co-citation analysis helps in tracing the evolution of these clusters and suggests future themes, research directions and methodological advances in the theme. PageRank analysis helps in identifying the top articles published on high-impact journals in the theme.

The study helps researchers by summarising existing literature and identifying key thematic areas. It also assists policymakers by recommending actions to improve knowledge management practises in small businesses to gain a competitive advantage. The paper suffers from the limitations of bibliometric analysis. The sample is collected from a single data source and a single type (journal articles) and the statistical accuracy of the analysis depends on the quality of the sample.

The study’s originality lies in using fit-for-purpose software in clustering the research and suggesting actions. To the best of the authors’ knowledge, this study is one of its kind in applying bibliometrics in studying and covering several aspects of knowledge management in small businesses with a combination of software.