Cesar Hernando Valencia

Prof. Dr. Cesar Hernando Valencia

Facultad de Ingeniería Mecatrónica, Universidad Santo Tomás, Bucaramanga, Santander, Colombia
orcid
Thinking, Writing and Enjoy

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

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

Representative Publications

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31 January 2023 in Inventions
Verified
Journal Article
Open access
PDF file
SVSebasrian Muñoz Vasquez
Sebasrian Muñoz Vasquez
ZPZuly Alexandra Mora Perez
Zuly Alexandra Mora Perez
Paolo Andrés Ospina HenaoPaolo Andrés Ospina Henao
Paolo Andrés Ospina Henao
Cesar Hernando ValenciaCesar Hernando Valencia
Cesar Hernando Valencia
MBMarcelo Becker
Marcelo Becker
JDJorge G. Díaz
Jorge G. Díaz
The article presents a finite element simulation for the stress analysis of a transfemoral prosthesis with damping for a 100 kg person in the balancing phase. The maximum force is exerted at this stage when the person supports his or her whole body on a single foot. Materials used included stainless steel and polymer matrix composites, for which mechanical testing was performed. The study applied the SolidWorks simulation software tools, where material properties were specified for each part that composes the prosthesis and considered loads, the fastenings, and the meshing. The simulation resembles the manufacturing process for each component, including the sole built by the novel composite fused deposition modeling technique. As a result of the simulation, the stress, displacement fields, and safety factor are obtained. Analysis of the safety factor indicates that the components can withstand the loads imposed. Finally, a fatigue analysis indicated that the most critically loaded component lasts at least 294,107 cycles at maximum constant loading.

17 October 2025 in Buildings
Verified
Journal Article
Open access
PDF file
ARAndrés Rodríguez-Torres
Andrés Rodríguez-Torres
Cesar Hernando ValenciaCesar Hernando Valencia
Cesar Hernando Valencia
LALuis Alvarez-Icaza
Luis Alvarez-Icaza
This study proposes a new approach to identify structural parameters under seismic excitation using classical and quantum-inspired algorithms. Traditional methods often struggle with complex effects, noise, and computing limits. A five-story building model with mass–spring–damper system was tested to find properties during earthquakes. The study used optimization methods including Genetic Algorithm (GA), Particle Swarm Optimization (PSO), and five quantum-inspired versions: Quantum Genetic Algorithm (QGA), Quantum Particle Swarm Optimization (QPSO), Quantum Non-Dominated Sorting Genetic Algorithm II (QNSGA-II), Quantum Differential Evolution (QDE), and Quantum Simulated Annealing (QSA). Additionally, statistical analysis used Shapiro–Wilk for normality, Levene and Bartlett for variance, ANOVA with Tukey–Bonferroni comparisons, Bootstrap model ranking, and Borda count. The results show that the quantum-inspired methods perform better than classical ones. QSA reduced mean squared error (MSE) by 15.3% compared to GA, and QNSGA-II reduced MSE by 8.6% and root mean squared error (RMSE) by 3.5%, with less variation and tighter rankings. The framework addresses computing cost and response time; quantum methods need significant computing power and their accuracy suits offline earthquake assessments and model updates. This balance helps monitor building health when real-time speed is less critical but accuracy matters. The method provides a scalable tool for checking civil structures and could enable digital twins.

21 August 2026 in Technologies
Verified
Journal Article
Open access
PDF file
Cesar Hernando ValenciaCesar Hernando Valencia
Cesar Hernando Valencia
RNRafael Augusto Núñez-R.
Rafael Augusto Núñez-R.
Marley Maria Bernardes Rebuzzi VellascoMarley Maria Bernardes Rebuzzi Vellasco
Marley Maria Bernardes Rebuzzi Vellasco
Jeison MarínJeison Marín
Jeison Marín
We present ESNformer, a hybrid architecture that couples an Echo State Network (ESN) reservoir with a Transformer encoder for classification of structured, multi-indicator assessment data: a fixed-order vector of complementary indicators per assessment instance rather than a repeated-measures time series. The reservoir acts as a fixed nonlinear feature map over the indicator vector, while self-attention, made position-aware over the fixed column order, learns how each indicator’s evidence contributes to the final decision, so the two components, together, capture local, indicator-level detail and global, cross-indicator interactions within a single, end-to-end trainable model. Interpretability is treated as a first-class design requirement rather than an afterthought: the architecture is paired with an explainability layer combining SHAP feature attribution (reported both globally and per class), the model’s own attention weights, a deletion/insertion faithfulness test that quantitatively verifies which inputs the model actually relies on, and counterfactual maps that translate a prediction into an actionable, inspectable recommendation. We evaluate the architecture on a concrete case study, classifying Braille-literacy instructional recommendations from 15 pedagogical indicators grouped into three categories (Mangold’s, ABKL, and Progresar), using a benchmark of 900 real assessment instances (630 used, together with a class-conditional augmentation procedure, to build a 2100-instance training set) with validation and test partitions (135 instances each) kept exclusively real. On this benchmark, the tuned model reached 85.33% accuracy, 85.90% macro-precision, 85.33% macro-recall, an F1 score of 85.25%, and an AUC of 0.95 on the real test set. SHAP attribution, attention weights, and the faithfulness test converge on the same two dominant indicators (response time and error count): removing them alone collapses accuracy to chance, while retaining only them recovers most of the model’s accuracy. We report this transparently alongside a comparison against ESN-only, Transformer-only, and tabular baselines (logistic regression, decision tree, random forest, XGBoost, and an MLP) on the same data and discuss what the hybrid architecture and its explainability pipeline add beyond what the two dominant indicators already explain and how the approach generalizes to other tabular and mixed-granularity assessment settings that require both predictive accuracy and a verifiable account of what drove each decision.

23 June 2025 in The Journal of Prosthetic Dentistry
Verified
Journal Article
Open access
LCLina R. Cuellar
Lina R. Cuellar
OLOscar Rodrigo López-Vaca
Oscar Rodrigo López-Vaca
RMRuth A. Martínez-Vega
Ruth A. Martínez-Vega
Cesar Hernando ValenciaCesar Hernando Valencia
Cesar Hernando Valencia
With the evolution of computer-aided design and computer-aided manufacturing (CAD-CAM), the digitally guided fabrication of implant-supported fixed dental prostheses has become increasingly precise and customized. Conventional substructure designs may fail to ensure a passive fit or adequate biomechanical performance in edentulous patients with severe mandibular bone resorption. Anatomic limitations and load concentration at the bone-implant interface present significant challenges for long-term prosthetic success. This article describes a step-by-step digital technique for designing a custom bar for a mandibular implant-supported prosthesis using cone beam computed tomography, 3-dimensional anatomic reconstruction with segmentation software program, and CAD tools. The design was biomechanically validated through finite element analysis to evaluate stress distribution and deformation under functional loading. This workflow enables clinicians and dental laboratory technicians to preclinically optimize the geometry and material behavior of the substructure, enhancing predictability and reducing complications in complete arch mandibular rehabilitation.

2 December 2020
Verified
Book Chapter
Open access
SVSebasrian Muñoz Vasquez
Sebasrian Muñoz Vasquez
Paolo Andrés Ospina HenaoPaolo Andrés Ospina Henao
Paolo Andrés Ospina Henao
Cesar Hernando ValenciaCesar Hernando Valencia
Cesar Hernando Valencia
MBMarcelo Becker
Marcelo Becker
ZPZuly Alexandra Mora Perez
Zuly Alexandra Mora Perez
SVS.M. Vásquez
S.M. Vásquez

16 December 2022
Verified
Conference Paper
Open access
CVCristian Muoz Villalobos
Cristian Muoz Villalobos
LFLeonardo Alfredo Forero
Leonardo Alfredo Forero
HMHarold D de Mello
Harold D de Mello
Cesar Hernando ValenciaCesar Hernando Valencia
Cesar Hernando Valencia
Alvaro David Orjuela-CañónAlvaro David Orjuela-Cañón
Alvaro David Orjuela-Cañón
MPMarco Aurelio AURELIO CAVALCANTI Pacheco
Marco Aurelio AURELIO CAVALCANTI Pacheco
Natural Language Processing (NLP) techniques are increasingly powerful for interpreting a person’s feelings and reaction to a product or service. Sentiment analysis has become a fundamental tool for this interpretation, and it has studies in languages other than English. This type of application is uncommon and unheard of in Portuguese. This article presents a sentiment analysis classification based on Portuguese social media comments. Representation of word embeddings with both pre-trained Glove and Word2Vec models were generated through a corpus entirely in Portuguese. This article presents a set of results with different models of pre-trained layers and deep learning models exclusive to the Portuguese language on social networks. Two classification models were used and compared: (i) Bidirectional Long Short-Term Memory (BI-LSTM) and (ii) Bidirectional Gated Recurrent Unit (BI-GRU), achieving accuracy results of 99.1