Jimmy Gutierrez

Dr. Jimmy Gutierrez

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
25 April 2023 in Cancers
Verified
Journal Article
Open access
PDF file
FSFabián Silva-Aravena
Fabián Silva-Aravena
HDHugo Núñez Delafuente
Hugo Núñez Delafuente
JGJimmy Gutierrez
Jimmy Gutierrez
JMJenny Morales
Jenny Morales
Worldwide, the coronavirus has intensified the management problems of health services, significantly harming patients. Some of the most affected processes have been cancer patients’ prevention, diagnosis, and treatment. Breast cancer is the most affected, with more than 20 million cases and at least 10 million deaths by 2020. Various studies have been carried out to support the management of this disease globally. This paper presents a decision support strategy for health teams based on machine learning (ML) tools and explainability algorithms (XAI). The main methodological contributions are: first, the evaluation of different ML algorithms that allow classifying patients with and without cancer from the available dataset; and second, an ML methodology mixed with an XAI algorithm, which makes it possible to predict the disease and interpret the variables and how they affect the health of patients. The results show that first, the XGBoost Algorithm has a better predictive capacity, with an accuracy of 0.813 for the train data and 0.81 for the test data; and second, with the SHAP algorithm, it is possible to know the relevant variables and their level of significance in the prediction, and to quantify the impact on the clinical condition of the patients, which will allow health teams to offer early and personalized alerts for each patient.

3 November 2021 in Water
Verified
Journal Article
Open access
PDF file
JGJimmy Gutierrez
Jimmy Gutierrez
DMDaniel Mora-Melia
Daniel Mora-Melia
PIPedro L. Iglesias-Rey
Pedro L. Iglesias-Rey
F. Javier Martínez-SolanoF. Javier Martínez-Solano
F. Javier Martínez-Solano
YSYamisleydi Salgueiro-Sicilia
Yamisleydi Salgueiro-Sicilia
The investment and operating costs of pumping stations in drinking water distribution networks are some of the highest public costs in urban sectors. Generally, these systems are designed based on extreme scenarios. However, in periods of normal operation, extra energy is produced, thereby generating excess costs. To avoid this problem, this work presents a new methodology for the design of pumping stations. The proposed technique is based on the use of a setpoint curve to optimize the operating and investment costs of a station simultaneously. According to this purpose, a novel mathematical optimization model is developed. The solution output by the model includes the selection of the pumps, the dimensions of pipelines, and the optimal flow distribution among all water sources for a given network. To demonstrate the advantages of using this technique, a case study network is presented. A pseudo-genetic algorithm (PGA) is implemented to resolve the optimization model. Finally, the obtained results show that it is possible to determine the full design and operating conditions required to achieve the lowest cost in a multiple pump station network.

2 May 2023 in Buildings
Verified
Journal Article
Open access
PDF file
ABAlexis Andrés Barrientos
Alexis Andrés Barrientos
PBPablo Ballesteros-Perez
Pablo Ballesteros-Perez
DMDaniel Mora-Melia
Daniel Mora-Melia
Alberto Cerezo-NarváezAlberto Cerezo-Narváez
Alberto Cerezo-Narváez
JGJimmy Gutierrez
Jimmy Gutierrez
Completing a project on time and on budget are essential factors for the success of any project. One technique that allows predicting the final cost of a project is earned value management (EVM). In this technique, different mathematical methods for predicting the final project cost have been proposed over the last 30 years. These formulas make use of activities’ actual costs and durations as the project progresses. EVM is a technique widely used by many project management professionals. However, very few studies have compared the stability and accuracy of the multiple existing methods for predicting the final cost of the project (commonly abbreviated as estimated cost at completion, EAC). This study compares the stability and accuracy of 30 deterministic cost prediction methods (EAC) in EVM. For this purpose, a representative database of 4100 simulated projects of various topological structures is used. Our results suggest that the methods with the simplest mathematical configurations achieve better stability and accuracy performance. Knowing which EVM methods are the most stable and accurate for predicting the final cost of the project will help project practitioners choose the most reliable cost prediction techniques when they are managing their own projects in real contexts.

8 February 2025 in Technologies
Verified
Journal Article
Open access
PDF file
FSFabián Silva-Aravena
Fabián Silva-Aravena
JMJenny Morales
Jenny Morales
Manoj JayabalanManoj Jayabalan
Manoj Jayabalan
MRMuhammad Ehsan Rana
Muhammad Ehsan Rana
JGJimmy Gutierrez
Jimmy Gutierrez
Surgical waiting lists present significant challenges to healthcare systems, particularly in resource-constrained settings where equitable prioritization and efficient resource allocation are critical. We aim to address these issues by developing a novel, dynamic, and interpretable framework for prioritizing surgical patients. Our methodology integrates machine learning (ML), stochastic simulations, and explainable AI (XAI) to capture the temporal evolution of dynamic prioritization scores, qp(t), while ensuring transparency in decision making. Specifically, we employ the Light Gradient Boosting Machine (LightGBM) for predictive modeling, stochastic simulations to account for dynamic variables and competitive interactions, and SHapley Additive Explanations (SHAPs) to interpret model outputs at both the global and patient-specific levels. Our hybrid approach demonstrates strong predictive performance using a dataset of 205 patients from an otorhinolaryngology (ENT) unit of a high-complexity hospital in Chile. The LightGBM model achieved a mean squared error (MSE) of 0.00018 and a coefficient of determination (R2) value of 0.96282, underscoring its high accuracy in estimating qp(t). Stochastic simulations effectively captured temporal changes, illustrating that Patient 1’s qp(t) increased from 0.50 (at t=0) to 1.026 (at t=10) due to the significant growth of dynamic variables such as severity and urgency. SHAP analyses identified severity (Sever) as the most influential variable, contributing substantially to qp(t), while non-clinical factors, such as the capacity to participate in family activities (Lfam), exerted a moderating influence. Additionally, our methodology achieves a reduction in waiting times by up to 26%, demonstrating its effectiveness in optimizing surgical prioritization. Finally, our strategy effectively combines adaptability and interpretability, ensuring dynamic and transparent prioritization that aligns with evolving patient needs and resource constraints.

24 March 2023 in Mathematics
Verified
Journal Article
Open access
PDF file
JGJimmy Gutierrez
Jimmy Gutierrez
DMDaniel Mora-Melia
Daniel Mora-Melia
BMBastián Alberto Valdivia Muñoz
Bastián Alberto Valdivia Muñoz
FSFabián Silva-Aravena
Fabián Silva-Aravena
PIPedro L. Iglesias-Rey
Pedro L. Iglesias-Rey
The design of pumping stations in a water distribution network determines the investment costs and affects a large part of the operating costs of the network. In recent years, it was shown that it is possible to use flow distribution to optimize both costs concurrently; however, the methodologies proposed in the literature are not applicable to real-sized networks. In these cases, the space of solutions is huge, a small number of feasible solutions exists, and each evaluation of the objective function implies significant computational effort. To avoid this gap, a new method was proposed to reduce the search space in the problem of pumping station design. This method was based on network preprocessing to determine in advance the maximum and minimum flow that each pump station could provide. According to this purpose, the area of infeasibility is limited by ranges of the decision variable where it is impossible to meet the hydraulic constraints of the model. This area of infeasibility is removed from the search space with which the algorithm works. To demonstrate the benefits of using the new technique, a new real-sized case study was presented, and a pseudo-genetic algorithm (PGA) was implemented to resolve the optimization model. Finally, the results show great improvement in PGA performance, both in terms of the speed of convergence and quality of the solution.

25 October 2022 in Mathematics
Verified
Journal Article
Open access
PDF file
FSFabián Silva-Aravena
Fabián Silva-Aravena
JGJimmy Gutierrez
Jimmy Gutierrez
HDHugo Núñez Delafuente
Hugo Núñez Delafuente
RTRoberto M. Toledo-Molina
Roberto M. Toledo-Molina
The coronavirus pandemic has intensified the strain on medical care processes, especially waiting lists for patients under medical management. In Chile, the pandemic has caused an increase of 52,000 people waiting for care. For this reason, a high-complexity hospital (HCH) in Chile devised a decision support system (DSS) based on multi-criteria decision-making (MCDM), which combines management criteria, such as critical events, with clinical variables that allow prioritizing the population of chronic patients on the waiting list. The tool includes four methodological contributions: (1) pattern recognition through the analysis of anonymous patient data that allows critical patients to be characterized; (2) a score of the critical events suffered by the patients; (3) a score based on clinical criteria; and (4) a dynamic–hybrid methodology for patient selection that links critical events with clinical criteria and with the risk levels of patients on the waiting list. The methodology allowed to (1) characterize the most critical patients and triple the evaluation of medical records; (2) save medical hours during the prioritization process; (3) reduce the risk levels of patients on the waiting list; and (4) reduce the critical events in the first month of implementation, which could have been caused by the DSS and medical decision-making. This strategy was effective (even during a pandemic period).