Valencia-Aragón, Kevin
Preferred name
Valencia-Aragón, Kevin
Main Affiliation
Quito
13 results
Now showing 1 - 10 of 13
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Item type:Publication, Learning Through Play: Implementing an Educational Escape Room for Teaching Traditions and Culture(2025); ; ; 21 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Optimizing Agriculture with LoRaWAN and HCI: A Smart Approach to Sustainable Farming(2025); ; 24 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Environmental Patterns of Phytoplankton Community Composition Across Lentic and Lotic Systems in Ecuador(2026); Phytoplankton are key indicators of water quality and low-cost tools for freshwater monitoring, yet their diversity and ecological drivers remain poorly documented in the Tropical Andes. This study provides the first national-scale, multi-ecosystem assessment of net phytoplanktonic communities (including microalgae and cyanobacteria), across Ecuador, integrating physicochemical, multivariate, and geospatial analyses. Eighteen lakes and rivers from three biogeographic regions and a wide altitudinal gradient were surveyed, yielding 129 taxa, 77 identified at species level, the most comprehensive checklist reported to date for Ecuador. Community structure showed a clear lentic–lotic differentiation driven by hydrodynamic contrasts, while the absence of distance–decay patterns indicated high dispersal and environmental filtering pattern rather than spatial structuring. Anthropogenic pressure acted as a secondary gradient: pristine high-Andean lakes were dominated by desmids and diatoms, whereas agricultural and urban basins showed chlorophyte and potentially toxic cyanobacterial assemblages. Palmer’s Index detected organic pollution but underestimated eutrophication in endorheic, geochemically enriched lakes. Land-use effects presented strong basin-scale signals in lakes but weak correlations in rivers due to overriding hydromorphological constraints. These findings establish a robust spatial baseline for freshwater bioassessment in the Andes, demonstrating the value of phytoplankton as effective, low-cost indicators readily applicable to national water-quality assessment programs.8 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Indoor Monitoring System Based on Computer Vision for Fall Detection Oriented to Elderly Assistance(2025); 20 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Optimizing Agriculture with LoRaWAN and HCI: A Smart Approach to Sustainable Farming(2025); ; 31 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Kiteracy-PiFo: Technological Tool for Teaching the Rules of Grapheme-Phoneme Correspondence(2025); ; This study presents Kiteracy-PiFo, a technological tool designed to teach grapheme-phoneme correspondence to preschool students. Combining computer engineering and special education, the tool was developed to enhance Human-Computer Interaction in early literacy education. Despite challenges, including unforeseen events and technical issues, the tool was successfully implemented across schools in Cartago, Costa Rica. Statistical analysis revealed significant differences in vowel recognition between the experimental group using Kiteracy-PiFo and the control group using traditional methods, with the experimental group achieving higher results in less time. These findings suggest that integrating innovative technologies like Kiteracy-PiFo into educational practices can effectively accelerate learning in early childhood settings. However, successful implementation depends on strong pedagogical support and alignment with psychological principles to meet students’ cognitive and emotional needs.18 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Microplastics in Two Tropical Andean Lakes: Contrasting Human-Impacted and Minimally Disturbed Watersheds(2026); Microplastics (MPs) are emerging contaminants in freshwater systems, yet their sources and transport pathways in tropical high-altitude lakes remain poorly understood. This study quantified and characterized MPs in two Andean lakes in Ecuador with contrasting watershed conditions: San Pablo (2672 m a.s.l.), influenced by agricultural and urban land use, and Caricocha (3724 m a.s.l.), a protected high-Andean lake. Sixteen samples per lake were collected during four field campaigns. MPs were identified using visual and morphological criteria, and classified by shape, color, and size. MP concentrations were higher in San Pablo (238 ± 32 MP m−3, mean ± SD) than in Caricocha (32 ± 10 MP m−3). Fibers dominated (87.3%), followed by fragments, while microspheres were detected only in Caricocha. MP concentrations showed positive correlations with urban-agricultural land use (ρ = 0.87, p < 0.0001) and negative correlations with natural vegetation cover (ρ = −0.87, p < 0.0001). Principal Component Analysis linked fiber abundance and small size classes (<500 µm) and anthropogenic land use, consistent with surface runoff and wastewater-associated pathways. In contrast, MPs in the protected lake may originate from long-range atmospheric deposition. These results indicate that watershed configuration and protection status shape MP inputs in high-Andean lakes.5 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Evaluating Signage Accessibility for Individuals with Visual Impairments: A Case Study in Ecuador(2024); ; 10 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Low-Cost Non-Wearable Fall Detection System Implemented on a Single Board Computer for People in Need of Care(2024); This work aims at proposing an affordable, non-wearable system to detect falls of people in need of care. The proposal uses artificial vision based on deep learning techniques implemented on a Raspberry Pi4 4GB RAM with a High-Definition IR-CUT camera. The CNN architecture classifies detected people into five classes: fallen, crouching, sitting, standing, and lying down. When a fall is detected, the system sends an alert notification to mobile devices through the Telegram instant messaging platform. The system was evaluated considering real daily indoor activities under different conditions: outfit, lightning, and distance from camera. Results show a good trade-off between performance and cost of the system. Obtained performance metrics are: precision of 96.4%, specificity of 96.6%, accuracy of 94.8%, and sensitivity of 93.1%. Regarding privacy concerns, even though this system uses a camera, the video is not recorded or monitored by anyone, and pictures are only sent in case of fall detection. This work can contribute to reducing the fatal consequences of falls in people in need of care by providing them with prompt attention. Such a low-cost solution would be desirable, particularly in developing countries with limited or no medical alert systems and few resources.11 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Exploring the Effectiveness of Assistive Technology: A Preliminary Case Study Using Makey Makey, Tobii Eye Tracker, and Leap Motion(2024); ; Sandra Sanchez-GordónThis study evaluates the usefulness and efficacy of three different continuous input devices - Makey Makey, Tobii Eye Tracker 4C, and Leap Motion - in promoting computer engagement for people with disabilities. A preliminary pilot study was conducted with the participation of one person with several disabilities. They were given various tasks to accomplish using each continuous input device, and their performance was assessed. To conduct the study, an experimental environment including two computers and a designed interface had to be setup. The findings showed that Leap Motion had poor perceived usability and that Makey Makey had the best usability, followed by Tobii Eye Tracker 4C. The pilot study also emphasizes the difficulties and modifications needed for people with disabilities to use these input devices in an efficient manner. These results highlight how crucial it is to create inclusive interfaces and technologies in order to improve accessibility for a range of user demographics16