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Found 6341 publications
The Impact of Rebalancing Strategies on ETF Portfolio Performance
Publication Name: Journal of Risk and Financial Management
Publication Date: 2024-12-01
Volume: 17
Issue: 12
Page Range: Unknown
Description:
This research explores the efficacy of rebalancing strategies in a diversified portfolio constructed exclusively with exchange-traded funds (ETFs). We selected five ETF types: short-term U.S. Treasury bonds, U.S. equities, global commodities, U.S. real estate investment trusts (REITs), and a multi-strategy hedge fund. Using a 10-year historical period, we applied a unique simulation model to generate random portfolios with varying asset weights and rebalancing tolerance bands, assessing the impact of rebalancing premiums on portfolio performance. Our study reveals a significant positive correlation (r = 0.6492, p < 0.001) between rebalancing-weighted returns and the Sharpe ratio, indicating that effective rebalancing enhances risk-adjusted returns. Support vector regression (SVR) analysis shows that rebalancing premiums have diverse effects. Specifically, equities and commodities benefit from rebalancing with improved risk-adjusted returns, while bonds and REITs demonstrate a negative relationship, suggesting that rebalancing might be less effective or even detrimental for these assets. Our findings also indicate that negative portfolio rebalancing returns combined with positive rebalancing-weighted returns yield the highest average Sharpe ratio of 0.4328, highlighting a distinct and reciprocal relationship between rebalancing effects at the asset and portfolio levels. This research highlights that while rebalancing can enhance portfolio performance, its effectiveness varies by asset class and market conditions.
Open Access: Yes
DOI: 10.3390/jrfm17120533
Cloud spot instance price forecasting multi-headed models tuned using modified PSO
Publication Name: Journal of King Saud University Science
Publication Date: 2024-12-01
Volume: 36
Issue: 11
Page Range: Unknown
Description:
The increasing dependence and demands on cloud infrastructure have brought to light challenges associated with cloud instance pricing. The often unpredictable nature of demand as well as changing costs of supplying a reliable instance can leave companies struggling to appropriately budget to support a healthy cash flow while maintaining operating costs. This work explores the potential of multi-headed recurrent architectures to forecast cloud instance prices based on historical and instance data. Two architectures are explored, long short-term memory (LSTM) and gated recurrent unit (GRU) networks. A modified optimizer is introduced and tested on a publicly available Amazon elastic compute cloud dataset. The GRU model, enhanced by the proposed modified approach, had the most impressive outcomes with an MAE score of 0.000801. Results have undergone meticulous statistical validation with the best-performing models further analyzed using explainable artificial intelligence techniques to provide further insight into model reasoning and information on feature importance.
Open Access: Yes
Sorting for Sustainability: Harnessing Female Awareness of Zero Waste
Publication Name: Journal of Sustainability Research
Publication Date: 2024-12-01
Volume: 6
Issue: 4
Page Range: Unknown
Description:
Background: Sustainable Development Goal 12 focuses on sustainable consumption and production patterns. Females are more likely to adopt these sustainable consumption practices due to their environmental attitudes. The scope of the present research is to develop a Hungarian model that can provide a theoretical explanation for the formation, viability and empowerment of zero waste awareness among females as they are sensitive to the issue and may have sufficient knowledge about it. Methods: An online questionnaire was distributed in a university environment in Hungary, resulting in 160 responses after data cleaning. The model was constructed using Partial Least Squares Structural Equation Modelling (PLS-SEM). Results: The results show that for females, the factors waste sorting and zero waste practicality account for 72.4% of the variance in zero waste awareness. The Beta values indicate that both effects are positive with the effect of the first (βZWS-ZWA = 0.523) being stronger than the second (βZWP-ZWA = 0.389). In addition, it can be concluded that women’s attitudes toward waste sorting have a strong positive impact (R2 = 0.542, βZWS-ZWP = 0.736) on zero waste practicality. Conclusions: The zero waste attitudes of female university students’ behavior are significantly related to the selective collection of waste and the practical use of old products. In addition, waste separation is a practical approach to environmental responsibility, as there is no need to dispose of all end-of-life products if they can be recycled. The model could help the government understand the factors and the mindset from a female perspective in order to partially support the decision-making process related to sustainability.
Open Access: Yes
INVESTIGATION OF HEAT-AFFECTED ZONES OF THERMITE RAIL WELDINGS
Publication Name: Facta Universitatis Series Mechanical Engineering
Publication Date: 2024-12-01
Volume: 22
Issue: 4
Page Range: 689-710
Description:
The paper investigates the heat-affected zone (HAZ) of several rail joints executed by thermite rail welding (TW). The examined rail profile was 54E1 (UIC54). The rail steel categories were different: R260 and R400HT. The welding portions of the TWs fitted R350HT and R260 rail categories with normal welding gaps. The rail pieces were brand new, i.e., without any usage in the railway track. The authors executed Vickers-hardness tests (HV10) and material texture tests on the running surface of the rail head, as well as on slices cut from the rail head. The cutting was performed by the water jet method, five longitudinal direction slices with vertical cutting lines. The considered specimen lengths were 2×70 mm (i.e., 70 mm from the mid-point of the rail joint), however, the depths were 20 mm from the running surface. Therefore, the measuring spaces were 5 mm lengthwise and 2 mm in depth. The variation of the hardness values was determined considering the microstructures of the base steel material and the TW. For comparison, previously measured Elektrothermit SoW-5 and earlier own research were taken into consideration.
Open Access: Yes
Modeling the Efficiency of Resource Consumption Management in Construction Under Sustainability Policy: Enriching the DSEM-ARIMA Model
Publication Name: Sustainability Switzerland
Publication Date: 2024-12-01
Volume: 16
Issue: 24
Page Range: Unknown
Description:
The aim of this research is to study the influence of factors affecting the efficiency of resource consumption under the sustainability policy based on using the DSEM-ARIMA (Dyadic Structural Equation Modeling based on the Autoregressive Integrated Moving Average) model. The study is performed using the Thailand experience. The research findings indicate that continuous economic growth aligns with the country’s objectives, directly contributing to continuous social growth. This aligns with the country’s efficient planning. It demonstrates that the management aligns with the goal of achieving Thailand 5.0. Furthermore, considering the environmental aspect, it is found that economic and social growth directly impacts the ecological aspect due to the significant influence of resource consumption in the construction. The resource consumption in construction shows a growth rate increase of 264.59% (2043/2024), reaching 401.05 ktoe (2043), which exceeds the carrying capacity limit set at 250.25 ktoe, resulting in significant long-term environmental degradation. Additionally, considering the political aspect, it is found to have the greatest influence on the environment, exacerbating environmental damage beyond current levels. Therefore, the DSEM-ARIMA model establishes a new scenario policy, indicating that resource consumption in construction leads to environmental degradation reduced to 215.45 ktoe (2043), which does not exceed the carrying capacity. Thus, if this model is utilized, it can serve as a vital tool in formulating policies to steer the country’s growth toward Thailand 5.0 effectively.
Open Access: Yes
DOI: 10.3390/su162410945
An assessment of traffic education and its examination system—an extended House of Quality approach
Publication Name: Humanities and Social Sciences Communications
Publication Date: 2024-12-01
Volume: 11
Issue: 1
Page Range: Unknown
Description:
The goal of this article is to examine traffic education and its examination system, using a new approach based on the House of Quality method. While every country has its own legal rules and requirements regarding how traffic education and examinations are conducted, there is a direct relationship between traffic education, its examination system and road safety. Therefore the quality of such a complicated process is of great interest for both stakeholders: the authorities and the citizens. These stakeholders both have their own objectives regarding the system, consequently increasing its complexity. This article investigates, as its case study, the system in Hungary. The House of Quality method has been expanded to provide a unique approach to examine the goals and objectives of both stakeholders, revealing similarities and differences and their interrelationships. Secondary data on the effectiveness of the traffic education and examination system are also analysed. Based on the HOQ model representations of the goals and objectives of the stakeholders regarding the traffic education and exam system, it can be established that the stakeholder points of view are closer to each other in the case of the test system than that of the education system. However, there are unsolved contradictions between the stakeholders that have to be handled, as opinions regarding the quality of the service and the criteria of the stakeholders’ satisfaction are very diverse.
Open Access: Yes
Viral coat proteins decrease the gene silencing activity of cognate and heterologous viral suppressors
Publication Name: Scientific Reports
Publication Date: 2024-12-01
Volume: 14
Issue: 1
Page Range: Unknown
Description:
Plant viruses have evolved different viral suppressors of RNA silencing (VSRs) to counteract RNA silencing which is a small RNA-mediated sequence-specific RNA degradation mechanism. Previous studies have already shown that the coat protein (CP) of cucumber mosaic virus (CMV) reduced RNA silencing suppression (RSS) activity of the VSR of CMV, the 2b protein. To demonstrate the universality of this CP-VSR interference, our study included three different viruses: CMV and peanut stunt virus (PSV) from the Bromoviridae, and plum pox virus (PPV) from the Potyviridae family. The RSS activity of the three VSRs (CMV 2b, PSV 2b, and PPV HC-Pro) was compared using Agrobacterium-mediated transient expression in Nicotiana benthamiana and the effect of CMV CP, PSV CP and PPV CP was validated on the RSS activity of their cognate and heterologous VSRs as well. Furthermore, the VSRs were also evaluated in PTGS suppressor-deficient CMV mutant (CMV NVE/10–12/AAA) virus-infected plants. The joint presence of CPs and VSRs resulted in decreased RSS activity in each combination, regardless of the origin of the two proteins, suggesting a universal role of the viral CPs in fine tuning of RSS. Interestingly the PSV CP elicited the strongest negative effect on the RSS activity of all three VSRs.
Open Access: Yes
Structural behaviour of built-up I-shaped CFS columns
Publication Name: Scientific Reports
Publication Date: 2024-12-01
Volume: 14
Issue: 1
Page Range: Unknown
Description:
The utilization of cold-formed thin-walled members as structural members has gained significant popularity due to their advantages in fabrication, cost-effectiveness, and transportation convenience. However, the reduced thickness of the used sections poses challenges such as global, local, and distortional member buckling, leading to a decrease in their axial strength. This study focuses on addressing these challenges by connecting the channels together using screws as an alternative to welding, considering the cost, time, and ease of implementation. Conducting finite element analysis on structural columns built-up from cold-formed double C steel channels and subjected to axial loads, this paper verifies the numerical models used against experimental tests known from the literature. A comparison of experimental results with nonlinear FEA and AISI & AS/NZ standards reveals commendable agreement, particularly in predicting the buckling behavior of the built-up I-shaped CFS columns. While the results of the finite element analysis show an overestimation of approximately 3.6% compared to the experimental tests, the AISI and AS/NZS standards demonstrate a conservatism of about 3.0%. Furthermore, the current study investigates the influence of screw spacing on axial strength of built-up cold-formed steel columns. The findings are derived from 175 finite element experiments, evaluating seven different cross-sectional profiles with twelve distinct screw spacings. These spacings correspond to the half-wavelength of local, distortional, and global buckling, divided by values ranging from one to four. The screw spacing determined by half the local buckling half-wavelength along the webs’ centerline resulted in enhancements of 22%, 7%, 13%, and 11% in the critical elastic local, distortional, and global column buckling loads, as well as the nominal axial strength, respectively. These increases were even more pronounced for double-lane fasteners with the same spacing, yielding improvements of 25%, 46%, 17%, and 12%, respectively. For economic considerations, it is advisable to utilize single-lane fasteners with a half-wavelength equal to half the local buckling half-wavelength.
Open Access: Yes
Massive Open Online Courses (MOOCs) for Ethiopian Educators: Evaluating MOOCs as a global development tool
Publication Name: Research in Globalization
Publication Date: 2024-12-01
Volume: 9
Issue: Unknown
Page Range: Unknown
Description:
This study examines how global educational technologies interact with local development priorities through the lens of Massive Open Online Courses (MOOCs) in Ethiopian higher education teacher training. While digital learning platforms promise to democratize education globally, their effectiveness depends critically on alignment with local institutional contexts and development needs. Using survey data from 164 educators across 15 public universities, we investigate how institutional contexts shape technology integration patterns. Our analysis, integrating development theory with technology acceptance models, reveals three critical dimensions: the gap between awareness and participation reflects broader implementation challenges; previous experiences with development initiatives significantly influence adoption patterns; and state support proves crucial for enabling participation. While MOOCs offer potential for professional development in resource-constrained contexts, their effectiveness depends on complex interactions among infrastructure quality, institutional capacity, and material conditions. These findings contribute to the theoretical understanding of how global technological innovations interact with local institutional contexts to produce varied development outcomes, while offering practical insights for educational technology implementation in the Global South.
Open Access: Yes
