10 research outputs found
Constructing a One-Minute Video from a 2.586 Seconds Burst of Sentinel-2 Imagery to Show the Potential for Estimating Wave-Derived Nearshore Bathymetry by Using a Spatio-Temporal Cross-Correlation Method and a DMD-Based DIA
No full textTo effectively mitigate environmental changes and to manage coastal environments, a good under- standing of nearshore bathymetry and its evolution is required. The coastal zone is expected to be vulnerable in the foreseeable future due to the combined effects of increased coastal impacts and a growing coastal population. The use of spaceborne remote sensing methods has been developed in recent decades to estimate nearshore bathymetry. Compared to traditional methods, spaceborne remote sensing techniques offer a relatively large spatial coverage as well as frequent temporal mon- itoring. The Sentinel-2 mission (EC/ESA) is potentially able to provide regular bathymetry estima- tions, mainly due to its significant revisit time and freely accessible data.This research focuses on the development of a spatio-temporal cross-correlation model in order to construct a one-minute wave-representing video. The video is used to show the potential for wave- derived bathymetry estimation, exploiting a DMD-based DIA to invert depth. The model is ap- plied to two distinct datasets: a synthetic FUNWAVE dataset and Sentinel-2 imagery. The Sentinel-2 imagery covers research sites in Saint-Louis, Senegal and Capbreton, France. An application frame- work related to the model is furthermore developed by analysing a set of synthetic sinusoidal waves.Three model requirements are created based on the research objectives. The model should show wave propagation for at least one minute and, moreover, the waves in the video should accurately represent the wave field. Both requirements are demanded by the use of a DMD-based DIA. Lastly, the resulting video should enable an accurate bathymetry estimation. Based on the requirements, the developed spatio-temporal cross-correlation model includes four model parts: pre-processing, image resolution augmentation, wave characteristics estimation and video construction.The research has led to a range of insights. A discrepancy between the quality of constructed videos and related bathymetry estimations is observed. The videos as constructed by the model generally show a good representation of average wave propagation for a sufficiently long duration, while the bathymetry estimations are less accurate. The low quality of bathymetry estimations is explained by three main error sources: celerity estimation errors, the applied filtering methods and the way in which the video is constructed. These three error sources together lead to videos that lack pixel-wise detail and therefore decrease the bathymetry estimation quality. The developed application frame- work shows that estimating wave characteristics from Sentinel-2 imagery by means of the model is at the edge of possibilities. In temporal sense, relatively large celerity estimation errors are expected for wave periods lower than 5 s and higher than 7 s. The model is less sensitive for spatial parame- ters: as long as wavelengths are larger than circa 150 m the celerity estimation error is acceptable.All together, the developed model and related video constructions offer added value, although not for the purpose of a bathymetry estimation by means of a DMD-based DIA. The constructed videos represent wave propagation in an average sense and can therefore be exploited for wave-related purposes, e.g. obtaining wave spectra, estimating dominant wave direction and estimating wave climates. In general, the video offers a way to enlarge the temporal range of Sentinel-2 imagery. It is furthermore concluded that the model is probably more suitable for use in combination with other types of imagery, including satellite imagery with larger burst duration and increased spatial resolution as well as standard video imagery
Depth Inversion from Wave Frequencies in Temporally Augmented Satellite Video
No full textOptical satellite images of the nearshore water surface offer the possibility to invert water depths and thereby constitute the underlying bathymetry. Depth inversion techniques based on surface wave patterns can handle clear and turbid waters in a variety of global coastal environments. Common depth inversion algorithms require video from shore-based camera stations, UAVs or Xband-radars with a typical duration of minutes and at framerates of 1–2 fps to find relevant wave frequencies. These requirements are often not met by satellite imagery. In this paper, satellite imagery is augmented from a sequence of 12 images of Capbreton, France, collected over a period of ∼1.5 min at a framerate of 1/8 fps by the Pleiades satellite, to a pseudo-video with a framerate of 1 fps. For this purpose, a recently developed method is used, which considers spatial pathways of propagating waves for temporal video reconstruction. The augmented video is subsequently processed with a frequency-based depth inversion algorithm that works largely unsupervised and is openly available. The resulting depth estimates approximate ground truth with an overall depth bias of −0.9 m and an interquartile range of depth errors of 5.1 m. The acquired accuracy is sufficiently high to correctly predict wave heights over the shoreface with a numerical wave model and to find hotspots where wave refraction leads to focusing of wave energy that has potential implications for coastal hazard assessments. A more detailed depth inversion analysis of the nearshore region furthermore demonstrates the possibility to detect sandbars. The combination of image augmentation with a frequency-based depth inversion method shows potential for broad application to temporally sparse satellite imagery and thereby aids in the effort towards globally available coastal bathymetry data.Coastal EngineeringHydraulic Engineerin
Teaching Beyond Degrees of Non-Teacher Education DOST Scholars: A Phenomenology
No full textIntroduction :This study explores the experiences of the Department of Science and Technology (DOST) scholars by examining the challenges of the profession, the multiple roles they fulfill, the skills they apply, and the support they receive in their professional development.Methods: Using a descriptive phenomenological approach, the study examines the challenges, role expectations, skill applications, and support systems that shape their professional journeys. Ten non-teacher education graduates serving as Senior High School teachers were purposively selected and interviewed. Data was analyzed using thematic analysis. Results: Through a phenomenological approach, the research identified several themes, including (1) teaching is a challenging profession, (2) teaching is a multiple-role task, (3) teaching requires learned skills, and (4) teaching requires support from others. Findings reveal that these teachers face significant challenges due to a lack of pedagogical training, lesson planning skills, and classroom management expertise. Additionally, they navigate multiple responsibilities, including administrative duties and out-of-field teaching assignments. Despite these difficulties, they utilize their collegiate learning, social and communication skills, and innovative strategies such as game-based learning to enhance student engagement. The study also highlights the crucial role of mentorship, coaching, and colleague collaboration in supporting their teaching effectiveness and professional development. Conclusion: The narratives of the participants highlight the challenges, responsibilities, skill applications, and support systems that shape their professional journey. Findings reveal that teaching, while fulfilling, is a demanding profession requiring specific pedagogical competencies. The lack of formal training in pedagogy, lesson planning, and classroom management posed significant struggles, reinforcing the need for structured professional development programs for non-education graduates. Introducción: este estudio fenomenológico explora las experiencias vividas por académicos del Departamento de Ciencia y Tecnología (DOST) en Filipinas que obtuvieron títulos no docentes pero ingresaron a la profesión docente en el Departamento de Educación. Método: utilizando un enfoque fenomenológico descriptivo, el estudio examina los desafíos, las expectativas de rol, las aplicaciones de habilidades y los sistemas de apoyo que dan forma a sus trayectorias profesionales. Se seleccionaron y entrevistaron intencionalmente a diez graduados no docentes que se desempeñaban como docentes de secundaria. Los datos se analizaron mediante análisis temático. Resultados: a través de un enfoque fenomenológico, la investigación identificó varios temas, incluyendo (1) la enseñanza es una profesión desafiante, (2) la enseñanza es una tarea de múltiples roles, (3) la enseñanza requiere habilidades aprendidas y (4) la enseñanza requiere el apoyo de otros. Los hallazgos revelan que estos docentes enfrentan desafíos importantes debido a la falta de capacitación pedagógica, habilidades de planificación de lecciones y experiencia en gestión del aula. Además, asumen múltiples responsabilidades, incluidas tareas administrativas y tareas docentes fuera de campo. A pesar de estas dificultades, utilizan su aprendizaje universitario, sus habilidades sociales y de comunicación, y estrategias innovadoras como el aprendizaje basado en juegos para mejorar la participación de los estudiantes. El estudio también destaca el papel crucial de la tutoría, el entrenamiento y la colaboración entre colegas para apoyar la eficacia docente y el desarrollo profesional.Conclusión: las narrativas de los participantes resaltan los desafíos, responsabilidades, aplicaciones de habilidades y sistemas de apoyo que dan forma a su trayectoria profesional. Los hallazgos revelan que la enseñanza, aunque satisfactoria, es una profesión exigente que requiere competencias pedagógicas específicas. La falta de capacitación formal en pedagogía, planificación de lecciones y gestión del aula planteó luchas importantes, reforzando la necesidad de programas estructurados de desarrollo profesional para graduados no graduados en educación
Teaching Beyond Degrees of Non-Teacher Education DOST Scholars: A Phenomenology
No full textIntroduction :This study explores the experiences of the Department of Science and Technology (DOST) scholars by examining the challenges of the profession, the multiple roles they fulfill, the skills they apply, and the support they receive in their professional development.Methods: Using a descriptive phenomenological approach, the study examines the challenges, role expectations, skill applications, and support systems that shape their professional journeys. Ten non-teacher education graduates serving as Senior High School teachers were purposively selected and interviewed. Data was analyzed using thematic analysis. Results: Through a phenomenological approach, the research identified several themes, including (1) teaching is a challenging profession, (2) teaching is a multiple-role task, (3) teaching requires learned skills, and (4) teaching requires support from others. Findings reveal that these teachers face significant challenges due to a lack of pedagogical training, lesson planning skills, and classroom management expertise. Additionally, they navigate multiple responsibilities, including administrative duties and out-of-field teaching assignments. Despite these difficulties, they utilize their collegiate learning, social and communication skills, and innovative strategies such as game-based learning to enhance student engagement. The study also highlights the crucial role of mentorship, coaching, and colleague collaboration in supporting their teaching effectiveness and professional development. Conclusion: The narratives of the participants highlight the challenges, responsibilities, skill applications, and support systems that shape their professional journey. Findings reveal that teaching, while fulfilling, is a demanding profession requiring specific pedagogical competencies. The lack of formal training in pedagogy, lesson planning, and classroom management posed significant struggles, reinforcing the need for structured professional development programs for non-education graduates.
Author Correction : Common variants in Alzheimer's disease and risk stratification by polygenic risk scores
No full textGenetic discoveries of Alzheimer's disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimer's disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer's disease patients in APOE ɛ4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer's disease
High-resolution, large-scale laboratory measurements of a sandy beach and dynamic cobble berm revetment
No full textHigh quality laboratory measurements of nearshore waves and morphology change at, or near prototype-scale are essential to support new understanding of coastal processes and enable the development and validation of predictive models. The DynaRev experiment was completed at the GWK large wave flume over 8 weeks during 2017 to investigate the response of a sandy beach to water level rise and varying wave conditions with and without a dynamic cobble berm revetment, as well as the resilience of the revetment itself. A large array of instrumentation was used throughout the experiment to capture: (1) wave transformation from intermediate water depths to the runup limit at high spatio-temporal resolution, (2) beach profile change including wave-by-wave changes in the swash zone, (3) detailed hydro and morphodynamic measurements around a developing and a translating sandbar
From Visual Poetry to Digital Art: Image-Sound-Text, Convergent Media, and the development of New Media Languages
No full textThis research arises from my practice as a professional artist and my concern with issues of language and communication, particularly, the investigation of ways that arouse emotion and rational thought at once through language. Visual Poetry is a form of expression, which provokes both, and I saw the potential to expand its underlining principles further with the emergence of new technologies. With the digital medium, the main elements of visual and sound poetry: image, sound and text, can now be incorporated into the same piece of work.
The aim of this study is to explore new digital communicative systems that interweave visual, oral and semantic elements of language, to produce new media languages where the pre-linguistic and linguistic maintain their symbiotic identities. This study examines theoretical and artistic concerns emerging from the area in-between, which is created by interlacing image, sound and text in the same artwork.
It addresses the following series of questions:
How to transfer the main concepts from Visual Poetry to Digital Art?
How does computer technology transform image, sound and text to create new media languages?
What is the role of the author, reader, writer, producer in these new interactive textualities of image, sound and text?
How has this affected the new conventions of reading, looking, producing, using and thinking?
What does the digital add to the interactivelexts of Visual Poetry? What new meanings and processes of thinking, understanding and interpretation are appearing?
In which way do new technologies enhance the collaborative nature of practice?
This investigation brings knowledge from other disciplines into the art field and it explores different serniotic models such as the linguistic the visual and the aural. It blurs the barriers between the visual and the linguistic: between different art forms such as fine art, visual poetry and sound art/poetry in a new digital and technological arena. It questions the conventions applied to these critical areas with the aid of the new tools and critical concepts available through digital technology. This study challengest he viewer/listener/userw ith an interface of signsf rom different languages and serniotic systems: the visual (still and moving images), the audible and the linguistic, to participate and explore the multiple possibilities within a work. This investigation seeks to contribute to a new body of knowledge in the
development of the areas of Visual Poetry, Digital Art and the new genre of Electronic Poetry, by creating new, innovative, digital artworks for which, as a new form of expression, critical and analytical conventions are still in the process of development
Río Grande, Bravo... y sangriento: Narcotráfico, violencia y frontera en Ask a Policeman, del novelista chicano Rolando Hinojosa
No full textIn his detective novel Ask a Policeman (1998), and within the framework of the recently-emerged subgenre of narcoliterature, prestigious Chicano author Rolando Hinojosa explores not only the extreme violence and sadism which characterize such a criminal underworld, but also other topics such as the reality of the Chicano community nowadays, the current significance of the Mexico-US frontier, together with the interaction between the Spanish-speaking communities on both sides of the border.En su novela policíaca Ask a Policeman (1998), un escritor chicano de prestigio como Rolando Hinojosa se adentra en el reciente subgénero de la narcoliteratura para abordar no solo la violencia y el sadismo extremos que caracterizan dicho mundo criminal, sino también cuestiones como la realidad actual de la comunidad chicana, la función que la frontera entre México y Estados Unidos desempeña hoy día, o la relación entre las comunidades hispanohablantes de ambos países
Tristes tópicos cervantinos: periferia e identidad en algunos acercamientos posmodernos a Cervantes
No full textFor almost two decades, a group of North-american specialists in Cervantes have speculated americanist interpretation of Miguel de Cervantes’ novels, and namely of Don Quixote and Persiles y Sigismunda. In this article, the author analyzes the ideological bases of such a hypothesis as a posmodern critical theory of identity.Desde hace casi dos decadas, un grupo de cerventistas norteamericanas ha especulado con una interpretación americanista de las novelas de Miguel de Cervantes, en especial el Quijote y Persiles y Sigismunda. En el presente artículo, su autor analiza las bases ideológicas de tal hipótesis como una teoría arraigada en un posmodernismo crítico identitario
Recommended from our members
Respiratory muscle work and inspiratory muscle training on cytokines, oxidative stress and diaphragm fatigue in younger and older populations
No full textIncreased respiratory muscle work is encountered during strenuous whole-body exercise, and at rest in older adults and those with pulmonary limitations such as chronic obstructive pulmonary disease (COPD). When sufficiently strenuous it can result in diaphragmatic fatigue, increased blood lactate concentrations, and an alteration in respiratory muscle recruitment patterns. Increased respiratory muscle work also elevates cytokines interleukin-6 (IL-6) and interleukin-1β (IL-1β) within the respiratory muscles and systemically. There is mounting evidence that inflammation contributes significantly to the ageing process and age related diseases. Enhanced oxidative stress, glycogen depletion and diaphragmatic fatigue are all potential stimuli for this production. Whole-body exercise training can attenuate systemic inflammation and oxidative stress in younger adults during exercise, and in older adults who experience this at rest. An attenuation of muscle glycogen or increases in antioxidant enzymes may explain such reductions. Inspiratory muscle training (IMT) may also elicit similar adaptations in the inspiratory muscles, and thus also attenuate these markers
