Minerva

Optimizing Investment Portfolios Using Quadratic Programming: An Approach from the Markowitz Model

Ferdinand Eddington Ceballos Bejarano — 2025-06-20

The application of the Markowitz model is analyzed from five financial assets, a matrix of logarithmic returns was constructed to estimate the parameters. Through computational resolution, the optimal portfolio was obtained that complies with an established minimum return, simultaneously minimizing the level of risk. The results were visualized across the efficient frontier, identifying the optimal combinations between risk and return. It is concluded that the Markowitz model continues to be a valid and valuable tool for the rational management of investments, especially when it is complemented with computational resources that allow it to be adapted to various financial contexts.

Geographic Analysis of Land-Use Transformations by Unplanned Urban Expansion

Carlos Trujillo-Vera — 2025-06-20

This study looked at changes in land use between 2013 and 2023, caused by unplanned urban sprawl. A geospatial methodology based on Landsat 8 and Sentinel-2 imagery was applied, with supervised classification and GIS analysis. The results showed a 92% increase in urban land and a significant reduction in agricultural and forest cover. It was concluded that disorderly urbanization negatively affects territorial sustainability, evidencing the need for adequate planning.

The role of technology in geriatric care in Latin America: opportunities and challenges for its implementation

Janett Jesus Diaz Portillo — 2025-06-20

This paper analyzed the degree of implementation of emerging technologies in geriatric care in Latin America and identified the associated opportunities and challenges. The methodology was based on a narrative review of literature, including original articles, reviews, and scientific notes published between 2018 and 2024, consulted in databases such as PubMed, Scopus, Web of Science, SciELO, and Redalyc, in Spanish, English, and Portuguese. The results showed that these technologies are transforming health care in older adults, with an emphasis on telemedicine, which facilitates access to services and improves quality of life. It is concluded that its use optimizes communication and availability of geriatric care.

Gaps in the quality and accessibility of health care: a bibliographic analysis

Liliana Lourdes Fuentes Huaman — 2025-06-20

Healthcare quality represents a persistent challenge, particularly in developing countries, where structural and administrative gaps compromise population health. This study analyzed the main barriers affecting accessibility and quality of services in the Peruvian health system, through a bibliographic review of scientific databases such as Scielo, PubMed, and Redalyc, focusing on publications from the last five years. The findings reveal limitations in resources, infrastructure, and management, which prevent the provision of comprehensive and timely care, directly affecting well-being and equity in healthcare access.

Analysis of Financial Decision-Making in Small Enterprises: Gaps Between Financial Mathematics Theory and Business Practice

Renzo Rimaneth Rivero Fernandez — 2025-06-20

This study examined the gap between financial mathematics theory and the real-world financial decision-making practices of small entrepreneurs. Using a mixed-methods approach, surveys and a documentary review were conducted. The results revealed limited use of formal financial tools, despite frequent economic decisions. The study concludes that context-sensitive financial education is essential to improve decision-making quality and strengthen the sustainability of small businesses.

Radiation safety parameters and shielding calculation for an ionizing radiation emitting source

Gabriela Belen Urena Callay — 2025-07-14

El objetivo del estudio fue evaluar la seguridad radiológica de un laboratorio de Técnicas Nucleares de Ecuador que posee material radiactivo. Inicialmente se delimitaron zonas controladas y supervisadas, luego se determinó la tasa de dosis en cada una de estas. Con espectroscopia gamma se identificaron los radioisótopos presentes, de los cuales el ²³⁸U, ²³²Th, ²²⁶Ra, ²¹⁴Bi, tuvieron mayor actividad específica. Para el cálculo de blindaje se usó el método de Tasa de Dosis Máximas de Proyecto (TDMP), con lo cual se obtuvo el espesor adecuado de plomo (Pb) para blindar el material radiactivo.

Decentralized model for the operational management of transport in the conventional and executive public sectors

Robinson Anibal Domenech Bernabe — 2025-07-30

In this work, a decentralized model of operational management was applied to improve conventional and executive public transport. The type of research was applied, quantitative, quasi-experimental. The sample consisted of 132 leaders. A 26-item questionnaire was applied. Before applying the model, 86.36% of the leaders of the experimental group were at the low level. After applying the model, 89.39% reached the high level. It is concluded that the application of a decentralized model of operational management significantly improves conventional and executive public transport and that this model is reproducible in different scenarios and sectors.