Rojas, Omar
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Preferred name
Rojas, Omar
Official Name
Rojas Altamirano, Omar Guillermo
Alternative Name
orojas
Main Affiliation
ORCID
Scopus Author ID
22954196800
Researcher ID
K-1066-2013

Research Output
Now showing 1 - 10 of 77
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Matheuristics for the Design of a Multi-Step, Multi-Product Supply Chain with Multimodal Transport

2021 , Ruvalcaba-Sandoval, David A. , Olivares-Benitez, Elias , Rojas, Omar , Sosa-Gómez, Guillermo

Supply-chain network design is a complex task because there are many decisions involved, and presently, global networks involve many actors and variables, for example, in the automotive, pharmaceutical, and electronics industries. This research addresses a supply-chain network design problem with four levels: suppliers, factories, warehouses, and customers. The problem considered decides on the number, locations, and capacities of factories and warehouses and the transportation between levels in the supply chain. The problem is modeled as a mixed-integer linear program. The main contribution of this work is the proposal of two matheuristic algorithms to solve the problem. Matheuristics are algorithms that combine exact methods and heuristics, attracting interest in the literature because of their fast execution and high-quality solutions. The matheuristics proposed to select the warehouses and their capacities following heuristic rules. Once the warehouses and their capacities are fixed, the algorithms solve reduced models using commercial optimization software. Medium and large instances were generated based on a procedure described in the literature. A comparison is made between the algorithms and the results obtained, solving the model with a time limit. The algorithms proposed are successful in obtaining better results for the largest instances in shorter execution times.

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Tourism Destination Performance and Competitiveness: The Impact on Revenues, Jobs, the Economy, and Growth

2024 , Rudi Purwono , Miguel Angel Esquivias , Lilik Sugiharti , Rojas, Omar

We analyzed the relationship between tourism destination competitiveness (TDC) and economic performance using the Travel and Tourism Development Index (TTDI) and various tourism metrics. Employing a Structural Equation Model (SEM) and the latest available 2021 data, we focused on factors such as connectivity, infrastructure, demand drivers, sustainability, and the enabling environment. The findings indicated a positive correlation between these factors and the pillars of destination competitiveness. Key elements such as connectivity, infrastructure, demand drivers, sustainability, and enabling environment significantly influence TDC in Asia. Our research demonstrates that these indicators strongly affect various aspects of performance in Asian countries, including tourism arrivals, revenue, and job creation. We found a negative correlation between certain aspects of destination performance and tourism growth, suggesting that highly competitive destinations may experience lower growth rates than less competitive ones, thereby affecting the overall development of the sector. This highlights the necessity of specific strategies to leverage the positive influence of competitive tourist destinations on economic dynamics and job creation within a destination. This study highlights the crucial role of core resources and infrastructure in enhancing tourism performance and competitiveness, and advocates targeted efforts for sustainable and resilient sector growth. These findings offer valuable insights into the relationship between competitiveness and performance in the Asian tourism industry.

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Crude Oil and Biofuel Agricultural Commodity Prices

2018 , Semei Coronado , Rojas, Omar , Rafael Romero-Meza , Apostolos Serletis , Leslie Verteramo Chiu

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Automating the avocado supply chain with Blockchain and Off-chain

2020 , López-Pimentel, Juan Carlos , Rojas, Omar , Alcaraz Rivera, Miguel , Sosa-Gómez, Guillermo , Verteramo-Chiu, L.

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Time-Varying Spillovers between Currency and Stock Markets in the USA: Historical Evidence From More than Two Centuries

2020 , Semei Coronado , Rangan Gupta , Besma Hkiri , Rojas, Omar

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Blockchain and off-chain: A Solution for Audit Issues in Supply Chain Systems

2020 , López-Pimentel, Juan Carlos , Rojas, Omar , Raul Monroy

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Using hadamard transform for cryptanalysis of pseudo-random generators in stream ciphers

2020 , Sosa-Gómez, Guillermo , Rojas, Omar , Páez-Osuna, O.

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Analysis of the Number of Sides of Voronoi Polygons in PassPoint

2021 , Lisset Suárez-Plasencia , Joaquín A. Herrera-Macías , Carlos M. Legón-Pérez , Raisa Socorro-LLanes , Rojas, Omar , Sosa-Gómez, Guillermo

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Design of experiments and response surface methodology to tune machine learning hyperparameters, with a random forest case-study

2018 , Lujan-Moreno, Gustavo , Phillip R. Howard , Rojas, Omar , Douglas C. Montgomery

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Components to foster organizational resilience in tourism SMEs

2021 , Núñez-Ríos, Juan E. , Sánchez-García, Jacqueline Y. , Soto-Pérez, Manuel , Olivares-Benitez, Elias , Rojas, Omar

PurposeSmall- and medium-sized enterprises (SMEs) mainly rely on their structure and internal networks to achieve their goals and remain competitive. However, their limited internal capabilities and complex environments can hinder their stability. Thus, this study evaluated the relationships among specific factors toward fostering organizational resilience (OR) in tourism SMEs.Design/methodology/approachA multi-methodological approach was adopted to address this research study, including (1) social network analysis (SNA) to formulate the conceptual model and (2) construct validation through partial least squares path modeling (PLS-PM).FindingsThe six proposed hypotheses were supported. These results suggest that addressing these variables and relationships after considering management style and people development as critical factors can foster OR in tourism SMEs.Research limitations/implicationsThe ideas that were developed were constrained to the organizational domain. Although the results apply to the Mexican context, this limitation can be offset by extending the proposal to other emergent regions or organizations. This can also increase the generalization of the results and foster improvements in the approaches applied.Practical implicationsAcademics and managers must rethink resilience as the final state generated by multiple factors. This requires reconfiguring inner organizational interactions, providing more autonomy to operative units, reinforcing business intelligence and improving feedback mechanisms.Originality/valueThis research study contrasts previous studies because it proposes that SNA be exploited to avail of the advantages it confers in designing the conceptual model. In this regard, we present new relationships to promote OR and provide new avenues in order to improve the analysis of adaptation processes.

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