Search results

In this paper, the authors describe a more efficient and economical method for a splitting scheme for drift‐diffusion models for semiconductors. It enables one to calculate stationary and non‐stationary processes in semiconductor plasma.

A half‐implicit absolutely stable method for 3D simulation of the transient processes in semiconductor devices is proposed. The calculations of transient processes in bipolar transistor were carried out and were compared with the results of 2D simulation.

This chapter studies the importance of implementation of innovational projects of technological growth through public–private partnership (PPP). The authors determine the probability of implementing a project of PPP depending on distribution of risks between its participants. Usage of the mechanism of PPP allows optimizing possible risks during implementation of innovational activities, attracting large business for creation and implementation of new technologies, and forming sustainable ties between R&D departments and business structures. The types of risks in the projects of PPP are given, as well as tendencies of their emergence depending on the stage of implementation of the innovational project, including the following: formation of policy on development of PPP; preparatory, implementary, commercialization of the results of joint activities; and monitoring and control over execution of the project. The algorithm of the system of risk management in innovational projects of technological growth on the platform of PPP is presented. The methods of overcoming the risks that appear during implementation of an innovational project of technological growth within PPP are given. A special attention should be paid to the fourth (distribution of risks) and fifth (reduction of risks) stages. During implementation of innovational projects with application of a business model of PPP, the risks are dealt with by the participant who can manage them better. Reduction of risks is achieved better if several strategies are used – for decreasing the influence of the risk on the innovational project (strategies of risk evasion, acceptance of the risk situation, compensation, transfer, and reduction).

The chapter is devoted to the factors aimed at optimizing the partnership of public and private sectors in the sphere of public infrastructure development. In modern conditions of economic slowdown and budget consolidation in Russia, the infrastructure has become the most important driver of economic growth and public–private partnership (PPP) – the most perspective form of cooperation of public and private investors of infrastructure projects. PPP interpretation as a structural relationship of economic system allows the authors to model optimal combination of formal and informal institutions in order to stimulate long-term economic growth. It becomes promising to model replacement of budget funds by private investment to ensure positive impact on the Russian development despite the budget consolidation. It could only be achieved in the case of formal institutionalization of appropriate conditions for private investors as to low transactional costs and attractive financial parameters. There have been determined some PPP standards connected with public infrastructure projects in order to reduce capital expenditures of the budget funds and increase the inflow of private investment. The authors have managed to obtain model estimates and graphic interpretation of government expenditures’ efficiency increase that could help to structure the fiscal conditions to induce positive multiplier effect as a result of PPP forms improvement in the public infrastructure development.

The postindustrial economy did not take the place of previous types of economy. More than that, by definition, it hasn't become “post”-industrial in point of fact: relations with regard to the production of tangible goods define the imperative of industrialism, yet with a modern science and technology stage of development. The present-day production becomes increasingly automated, leading to the absence of demand for psychophysiological properties of man and labor in general. At the same time, highly qualified personnel who are able to control complex information management systems come to the fore. New types of energy and manmade materials appear; socioeconomic human living environment becomes more complicated. These processes are an objective phenomenon. However, the technological revolution is manifested differently in the “central” and “peripheral” countries. In the Russian Federation, formation of the innovational takes place in the conditions of integration of the resource model and opposition of the institutes that fund it. The crisis stimulates the conceptual search and does not deny the scientifically based classics.

The purpose of the current study is development of effective and fast algorithm for optimization the arrangement of temporary fasteners during aircraft assembly.

Combinatorial nature, uncertain input data, sensitivity to mechanical properties and geometric tolerances are the specific features of the fastening optimization problem. These characteristics make the problem-solving by standard methods very resource-intensive because the calculation of the objective function requires multiple solution of contact problems. The work provides an extended description of the geodesic algorithm (GA) which is a novel non-iterative optimization approach avoiding multiple objective function calculations.

The GA makes it possible to optimize the arrangement of temporary fasteners during the different stages of the assembly process. The objective functions for the optimization are number of installed fasteners and quality of contact between joined parts. The mentioned properties of the GA also make it possible to introduce an automatic procedure for optimizing fastener arrangement into everyday practice of aircraft manufacturing.

The algorithm has been applied to optimization of the assembly process in Airbus company.

Performance of the GA is orders of magnitude greater than standard optimization algorithms while maintaining the quality of results. The use of the assembly process specifics is the main limitation of the GA, because it cannot be automatically applied to optimization problems in other areas. High speed of work and quality of the results make it possible to use it for real optimization problems on assembly line in the production of commercial airliners.

The authors consider the problem of optimizing temporary fastener patterns in aircraft assembly. Minimizing the number of fasteners while maintaining final product quality is one of the key enablers for intensifying production in the aerospace industry. The purpose of this study is to formulate the fastener pattern optimization problem and compare different solving approaches on both test benchmarks and rear wing-to-fuselage assembly of an Airbus A350-900.

The first considered algorithm is based on a local exhaustive search. It is proved to be efficient and reliable but requires much computational effort. Secondly, the Mesh Adaptive Direct Search (MADS) implemented in NOMAD software (Nonlinear Optimization by Mesh Adaptive Direct Search) is used to apply the powerful mathematical machinery of surrogate modeling and associated optimization strategy. In addition, another popular optimization algorithm called simulated annealing (SA) was implemented. Since a single fastener pattern must be used for the entire aircraft series, cross-validation of obtained results was applied. The available measured initial gaps from 340 different aircraft of the A350-900 series were used.

The results indicated that SA cannot be applicable as its random character does not provide repeatable results and requires tens of runs for any optimization analysis. Both local variations (LV) method and MADS have proved to be appropriate as they improved the existing fastener pattern for all available gaps. The modification of the MADS' search step was performed to exploit all the information the authors have about the problem.

The paper presents deterministic and probabilistic optimization problem formulations and considers three different approaches for their solution. The existing fastener pattern was improved.

The digital platform (DP) develops through a network capability that combines technological infrastructure and resources to provide goods or services. This article investigates how institutions influence the development of the DP entrepreneurship ecosystem (EE) in a developing economy context.

An exploratory qualitative approach based on interviews with 33 DP business executives in Nigeria was the chosen research method. The interview method took the form of face-to-face, telephone and zoom video meetings, depending on the respective preferences of the participants. The research philosophy is based on interpretivism. Hence, the collected data were analyzed thematically and interpreted to make sense of the business executives' perspectives about the DP landscape as well as its institutional enablers and barriers.

The findings reveal institutional elements that are either too underdeveloped or weak to nurture an effective DP system resulting in high cost of doing business. A key cultural challenge is obtaining an honest workforce and managers. Also, there is lack of effective policies, weak regulation, multiple taxation and foreign competition, which affects local digital firms. Although cultural diversity has several merits, differences in cultural values and languages create marketing and promotion challenges. Moreover, the low level of digital literacy between Generation Z, Millennials and others, such as Baby Boomers and Generation X, poses a significant challenge concerning customer segmentation.

Research on digital technologies, the complexity of platform architectures and institutional logic has attracted interest in recent years. This article explored the institutional logic influencing the development of DP ecosystem (providing knowledge about EE in a developing world context). Despite the institutional challenges, there are multiple opportunities for Nigerian DP sector to flourish in the fast-growing economy.

The value of this article is related to how micro-, meso- and macro-institutional forces combine to support or become barriers to the development of the DP ecosystem, especially in developing economies where digitalization is creeping into every business sector and society.