VGTU Journals (Vilnius Gediminas Technical University - Vilnius Tech)
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A uniformly accurate hybrid difference approximation of a system of singularly perturbed reaction-diffusion equations with delay using grid equidistribution
No full textThis paper presents a uniformly accurate difference approximation for a system of singularly perturbed reaction-diffusion equations with delay. The proposed method utilizes an appropriate combination of exponential and cubic spline difference schemes. It employs grid equidistribution to address the challenges posed by the multiscale nature of these systems, which often feature sharp gradients and boundary layers. The grid is generated based on the equidistribution of a positive monitor function, a linear combination of a constant floor and a power of the second derivative of the solution. By using adaptive mesh generation and a spline difference method, the approach enhances the accuracy of the numerical solutions while maintaining computational efficiency. Numerical experiments validate the uniform convergence and theoretical findings, demonstrating the method’s robustness irrespective of the perturbation parameter size
The role of network value alignment (NVA) in improving marketing performance
No full textThis research was conducted to identify factors in enhancing marketing performance by testing several aspects such as service orientation, service climate, and network value alignment (NVA). Furthermore, an identification was performed on the factors influencing the improvement of marketing performance from the perspective of Service-Dominant Logic (SDL) theory. This research was conducted on 226 respondents, comprising managers of microfinance institutions in Central Java, Indonesia, with a participation rate of 75%. The data was analyzed using structural equation modeling and AMOS 24 software was adopted in testing the hypotheses. The results showed that NVA strengthened the influence of service orientation on microfinance marketing performance through the support of service climate. This research was conducted on microfinance institutions that had characteristics of close social relations with customers. Further research should be performed on more heterogeneous companies to obtain broader and deeper results in managing NVA and enhancing marketing performance. A new perspective was provided on SDL theory by introducing NVA as an important antecedent in driving service climate and marketing performance
Generalized practical stability of Hopfield-type neural networks differential equations
No full textThis paper investigates the boundedness and practical stability properties of solutions for a class of neural differential equations inspired by Hopfield-type neural networks. Specifically, we develop a novel analytical framework that extends beyond traditional Lyapunov stability theory, Barbalat-type arguments, and fixed-point methods by relaxing common structural assumptions such as smoothness and global Lipschitz continuity. Our approach broadens the class of admissible systems to include nonlinearities with weaker growth conditions and time-varying perturbations that are not easily handled by classical techniques. Sufficient conditions are established to ensure the existence of a globally exponentially stable neighborhood of the origin, even in the presence of varying perturbation conditions. Furthermore, numerical examples are provided to demonstrate and validate the main result
Substitution or creation? Identifying the role of artificial intelligence in employment
No full textRecognising the significant role of artificial intelligence in the labour market is essential for China to develop sustainably. The research utilises the mixed frequency vector auto-regression (MF-VAR) technique, which would innovatively incorporate data at different frequencies into one model to identify the intricate correlation between the monthly artificial intelligence index (AII) and the quarterly unemployment rate (UR) in China. Through comparison, the MF-VAR method has a more substantial explanatory power than the low-frequency VAR (LF-VAR) model, the impulse responses of the former reveal that AII exerts favourable and adverse influences on UR. Among them, the positive effect occurs on the AII in the first and second months. In contrast, the negative one appears on the AII in the third month, highlighting that artificial intelligence has both stimulating and inhibiting effects on the labour market in China. By analysing UR’s predictive error variance decomposition, the total impact of China’s artificial intelligence technology on employment is a substitution; this outcome is accordant with the theoretical dis¬cussion. In the new round of scientific and technological revolution and industrial transformation, meaningful recommendations for China would be put forward to avert the wave of unemployment brought by the development of artificial intelligence technology.
First published online 09 September 202
How do we know in design? Exploring knowledge and inquiry in architectural design
No full textThis paper examines the intricate relationship that exists between the field of architecture and the role that research can play in it, by describing how this relationship has manifested itself in academic environments over the past two decades. The paper goes over modalities and methods to conduct architectural research, illustrates paradigmatic examples, and identifies a specific place for the formulation of what research can constitute in architecture. In analyzing architectural research connected to doctoral education, but also to the second cycle of higher education, the paper describes the Design Studio as the ideal place where teaching, research and learning can blend in to produce innovative and meaningful forms of knowledge
Promoting a green luxury product to belong or to stand out: a concept comparison test approach
No full textLiterature on luxury products reveals that product promotion involves two status-signaling goals as psychological mechanisms of social adaptation: the value-expressive function (to stand out: status enhancement) and the social-adjustive function (to be accepted: status affirmation). Traditionally, the value-expressive mechanism has been the most effective in promoting luxury goods. However, how these mechanisms operate for sustainable products, given the common assumption that luxury customers tend to disregard sustainability attributes, remains underexplored. This study challenges the aforementioned assumption by assessing how status-signaling goals influence willingness to pay for luxury products with sustainability attributes. Findings indicate that brand promotion that uses the social-adjustive function can be effective. This study recruits 464 participants and adopts an experimental approach involving concept comparison testing to explore the differences in consumers’ willingness to pay for a green luxury car. The car is presented with two distinct claims related to the above-mentioned luxury mechanisms and the absence or presence of a sustainable feature. Across all combinations of stimuli, participants perceive the sustainable luxury car as more appealing. This study shows that introducing a sustainability attribute in luxury brand communications can enhance consumers’ willingness to pay under either of the two status-signaling mechanisms
The dynamics of the FDI-productivity nexus in BRICS: a wavelet coherence study
No full textThe current study investigates the interrelationship between FDI inflows and total factor productivity (TFP) in BRICS economies comprising Brazil, Russia, India, China, and South Africa, along with newly added members Egypt, Ethiopia, Iran, Saudi Arabia, and the UAE. Previous research has often overlooked the country-specific factors that influence how productivity impacts FDI inflows. To address this gap, the study introduces methodological innovation by employing the Method of Moments Quantile Regression (MM-QR) with fixed effects, using annual data from 2012 to 2022. This method accounts for unobserved heterogeneity, allowing for a detailed analysis of how TFP affects FDI across different countries and quantiles. The study adds novelty by utilising wavelet coherence analysis to explore co-movements and causal relationships between FDI and key macroeconomic variables at different time scales. The results show that FDI inflows have a positive and significant relationship with GDP and trade openness while exhibiting a negative association with TFP. Over the long term (16–32 weeks), coherence remains relatively weak, but TFP demonstrates a more consistent impact on FDI inflows compared to the other variables. The study recommends that BRICS nations should enhance FDI’s impact by improving trade integration and regional cooperation to attract high-value investments and foster sustainable growth.
First published online 24 September 202
The efficiency of sustainable development goals 4 and 8 in China: impact of low fertility
No full textChina’s declining birth rate is gradually eroding the demographic dividend, potentially affecting education, employment, and the economy. This study constructs a meta two-stage dynamic Directional Distance Function (DDF) Data Envelopment Analysis (DEA) model under exogenous variable. It considers the birth rate as an exogenous variable to assess the efficiency of 30 Chinese provinces in achieving SDGs 4 and 8. Key findings include: (1) Integrating the birth rate into the analytical framework has enhanced overall efficiency in most provinces, particularly in the central region. The average efficiency across 30 provinces was 0.8, with minimal regional disparities. (2) The birth rate positively influences both SDG 4 and SDG 8, notably boosting SDG 4 efficiency. (3) Efficiency varies by province: 17 exhibit high efficiency in both SDG 4 and SDG 8, one shows low SDG 4 but high SDG 8 efficiency, two have high SDG 4 but low SDG 8 efficiency, and ten are inefficient in both goals. (4) Hebei, Shandong, and Guangdong have significant redundancy in education and social security investments. Hebei, Henan, and Shanxi show considerable deficiency in economic growth and employment, while Xinjiang and Inner Mongolia require further enhancements in energy efficiency.
First published online 23 September 202
Business model design in relocation management through qualimetric approach
No full textThe purpose of the study is to explore the application of qualitative methods in evaluating business relocation management, particularly focusing on optimizing business models through a qualimetric approach. The methodology involves qualitative research methods such as interviews, surveys and case studies to collect and analyze data on various aspects of business relocation. The article highlights the complexities of business relocation, emphasizing the legal, economic, social, cultural and environmental impacts on business activities. The research identifies key challenges and risks associated with relocation, particularly in the context of Ukrainian businesses relocating during wartime. Research implications suggest the need for further theoretical and analytical exploration of business relocation challenges and the development of comprehensive methodologies to evaluate relocation effectiveness. It offers valuable insights for improving communication with stakeholders, enhancing employee relations, and addressing legal and environmental considerations in relocation decisions. The study contributes to the optimization of business models through a qualimetric approach to relocation management
Study of a class of nonlinear heterogeneous diffusion with mixed phases under L∞ − data
No full textIn this paper we investigate a class of nonlinear degenerate parabolic equations involving heterogeneous (p,q)-Laplacian operators and subject to Dirichlet boundary conditions. These equations model complex diffusion phenomena with mixed-phase behavior in heterogeneous media. Our aim is to establish existence and uniqueness results for weak solutions under minimal regularity assumptions on the source term f, without requiring any control at infinity. The main difficulties stem from the degeneracy of the operator, the non-standard (p,q)-growth conditions, and the discontinuity of material phases. To overcome these challenges, we develop a variational framework based on Orlicz–Sobolev space theory and employ a generalized version of the Minty–Browder theorem to ensure the surjectivity of the nonlinear operator. Our approach yields new energy estimates, compactness results in non-reflexive settings, and stability under L∞-perturbations of the data. This work provides a rigorous mathematical foundation for analyzing nonlinear diffusion problems in complex and irregular environments