TrueLearn: A family of bayesian algorithms to match lifelong learners to open educational resources

The recent advances in computer-assisted learning systems and the availability of open educational resources today promise a pathway to providing cost-efficient high-quality education to large masses of learners. One of the most ambitious use cases of computer-assisted learning is to build a lifelong learning recommendation system. Unlike short-term courses, lifelong learning presents unique challenges, requiring sophisticated recommendation models that account for a wide range of factors such as background knowledge of learners or novelty of the material while effectively maintaining knowledge states of masses of learners for significantly longer periods of time (ideally, a lifetime). This work presents the foundations towards building a dynamic, scalable and transparent recommendation system for education, modelling learner’s knowledge from implicit data in the form of engagement with open educational resources. We i) use a text ontology based on Wikipedia to automatically extract knowledge components of educational resources and, ii) propose a set of online Bayesian strategies inspired by the well-known areas of item response theory and knowledge tracing. Our proposal, TrueLearn, focuses on recommendations for which the learner has enough background knowledge (so they are able to understand and learn from the material), and the material has enough novelty that would help the learner improve their knowledge about the subject and keep them engaged. We further construct a large open educational video lectures dataset and test the performance of the proposed algorithms, which show clear promise towards building an effective educational recommendation system

Semantic TrueLearn: Using Semantic Knowledge Graphs in Recommendation Systems

In informational recommenders, many challenges arise from the need to handle the semantic and hierarchical structure between knowledge areas. This work aims to advance towards building a state-aware educational recommendation system that incorporates semantic relatedness between knowledge topics, propagating latent information across semantically related topics. We introduce a novel learner model that exploits this semantic relatedness between knowledge components in learning resources using the Wikipedia link graph, with the aim to better predict learner engagement and latent knowledge in a lifelong learning scenario. In this sense, Semantic TrueLearn builds a humanly intuitive knowledge representation while leveraging Bayesian machine learning to improve the predictive performance of the educational engagement. Our experiments with a large dataset demonstrate that this new semantic version of TrueLearn algorithm achieves statistically significant improvements in terms of predictive performance with a simple extension that adds semantic awareness to the model

Geocronología de la Terraza Compleja de Arganda en el valle del río Jarama (Madrid, España)

La Terraza Compleja de Arganda (TCA), situada en el tramo bajo del río Jarama (Madrid), está formada por sucesivos apilamientos de secuencias fluviales denominados de abajo a arriba Arganda I, II, III y IV, en los que se han encontrado importantes yacimientos arqueológicos y paleontológicos del Pleistoceno (Áridos 1 y 2, Valdocarros o HAT), y numerosos conjuntos de industria lítica del Paleolítico inferior y medio. Hasta ahora, la única referencia cronológica disponible para la TCA era la proporcionada por el estadio evolutivo de los micromamíferos de los yacimientos Áridos 1 en Arganda I y Valdocarros en Arganda II. En este trabajo, se propone la equivalencia de las distintas unidades de la TCA con terrazas escalonadas y se establece un marco cronológico numérico, obtenido mediante dataciones de termoluminiscencia, luminiscencia ópticamente estimulada y racemización de aminoácidos. Arganda I (≈ T+30-32 m) se situaría hacia el final del MIS 11 o en el inicio del MIS 9, Arganda II (≈T+23-24 m) se correspondería con el inicio del MIS 7, Arganda III (≈T+18-20 m) se situaría entre el MIS 7 y el MIS 5, y Arganda IV comenzaría su deposición en el MIS 5 finalizando su sedimentación en el MIS 1 al sur de Arganda del Rey (Madrid)

The course of posterior antebrachial cutaneous nerve: Anatomical and sonographic study with a clinical implication

The course of the posterior antebrachial cutaneous nerve (PACN) was studied via ultrasound (US) and dissection. The aim of this study was to reveal the anatomical relationships of PACN with the surrounding structures along its pathway to identify possible critical points of compression. Nineteen cryopreserved cadaver body donor upper extremities were explored via US and further dissected. During US exploration, two reference points, in relation with the compression of the nerve, were marked using dye injection: (1) the point where the RN pierces the lateral intermuscular septum (LIMS) and (2) the point where the PACN pierces the deep fascia. Anatomical measurements referred to the lateral epicondyle (LE) were taken at these two points. Dissection confirmed the correct site of US-guided dye injection at 100% of points where the RN crossed the LIMS (10.5 cm from the LE) and was correctly injected at 74% of points where the PACN pierce the deep fascia (7.4 cm from the LE). There were variations in the course of the PACN, but it always divided from the RN as an only branch. Either ran close and parallel to the LIMS until the RN crossed the LIMS (84%) or clearly separated from the RN, 1 cm before it crossed the LIMS (16%). In 21% of cases, the PACN crossed the LIMS with the RN, while in the rest of the cases it always followed in the posterior compartment. A close relationship between PACN and LIMS, as well as triceps brachii muscle and deep fascia was observed. The US and anatomical study showed that the course of PACN maintains a close relationship with the LIMS and other connective tissues (such as the fascia and subcutaneous tissue) to be present in its pathology and treatment

Could AI Democratise Education? Socio-Technical Imaginaries of an EdTech Revolution

Artificial Intelligence (AI) in Education has been said to have the potential for building more personalised curricula, as well as democratising education worldwide and creating a Renaissance of new ways of teaching and learning. Millions of students are already starting to benefit from the use of these technologies, but millions more around the world are not. If this trend continues, the first delivery of AI in Education could be greater educational inequality, along with a global misallocation of educational resources motivated by the current technological determinism narrative. In this paper, we focus on speculating and posing questions around the future of AI in Education, with the aim of starting the pressing conversation that would set the right foundations for the new generation of education that is permeated by technology. This paper starts by synthesising how AI might change how we learn and teach, focusing specifically on the case of personalised learning companions, and then move to discuss some socio-technical features that will be crucial for avoiding the perils of these AI systems worldwide (and perhaps ensuring their success). This paper also discusses the potential of using AI together with free, participatory and democratic resources, such as Wikipedia, Open Educational Resources and open-source tools. We also emphasise the need for collectively designing human-centered, transparent, interactive and collaborative AI-based algorithms that empower and give complete agency to stakeholders, as well as support new emerging pedagogies. Finally, we ask what would it take for this educational revolution to provide egalitarian and empowering access to education, beyond any political, cultural, language, geographical and learning ability barriers

Cuadriceplastia de Judet : una alternativa quirúrgica para las rigideces graves en extensión de la rodilla

Introducción. La contractura en extensión de la rodilla es una complicación de las fracturas femorales con importante afectación de partes blandas. La cuadriceplastia de Judet es una alternativa quirúrgica para aumentar la movilidad. Material y métodos. Presentamos el caso de un paciente con rigidez grave de rodilla en extensión tras una fractura abierta bifocal de fémur estabilizada mediante osteosíntesis que se complicó con una infección y retardo de consolidación que requirió varias cirugías para su estabilización. Se realizó una cuadriceplastia de Judet seguida de una rehabilitación intensiva para conseguir aumentar la flexión de la rodilla. Resultados. En el postoperatorio inmediato conseguía una flexoextensión de 0-100º que se redujo a 95º a los 3 meses y se mantuvo a los 6 meses postoperatorios, con una fuerza muscular de 4 sobre 5 en cuádriceps y psoas. Conclusion. La cuadriceplastia de Judet es una técnica efectiva que permite recuperar la movilidad en caso de rigideces graves en extensión.Introduction. Extension contracture of the knee is a complication of femoral fractures with significant soft tissue injury. The Judet quadricepsplasty is a surgical alternative to increase knee range of motion. Material and methods. We report the case of a patient with severe stiffness of knee following an open bifocal femoral fracture stabilized by osteosynthesis that was complicated by an infection and delayed healing that required several surgeries for stabilization. Judet quadricepsplasty was performed followed by intensive rehabilitation for increasing knee flexion. Results. In the postoperative care flexion and extension of 0-100º was achieved, and reduced to 95º after 3 months and remained the same at 6 months postoperatively, with a muscular strength of 4 out of 5 in quadriceps and psoas. Conclusion. The Judet quadricepsplasty is an effective technique to regain mobility in case of severe extension stiffnes

Psychometric properties of a brief Spanish version of Stigmatizing Situations Inventory / Propiedades psicométricas de una versión breve en español del Inventario de Situaciones Estigmatizantes

Abstract Overweight and obese people are a frequent target of weight stigma. However, there are no Spanish-Language validated inventories measuring weight stigma situations. Therefore, we sought to validate a brief Spanish version of the Stigmatizing Situations Inventory (SSI) in a sample of Chilean adults. A psychometric study with 377 Chilean adults was designed (Mage = 45.0, SD = 8.7; 62% female). Twenty-four items available from two previous versions of the SSI developed were back-translated from English to Spanish, and semantically adapted to the Chilean sample. We explored the factorial structure with 173 participants, and then confirmed it with 204 subjects. We obtained evidence of concurrent validity with other psychological measures, as well as evidence of reliability. Our results identified a single factor structure grouping 10-items, with factorial loadings greater than .60. The overall fit indices are excellent. There is evidence of concurrent validity with body mass index (r = .43), anger (r = .19), anxiety (r = .29), and daily life discrimination (r = .26); all with p .60 e indicadores de bondad de ajuste excelentes. La consistencia interna de la escala fue alta (a = .91, ). Además se obtuvo evidencia de la validez concurrente del ISE con otras medidas: índice de masa corporal (r = .43), ira (r = .19), ansiedad (r = .29) y discriminación en la vida diaria (r = .26); todos con p < .05. La versión breve en español del ISE mostró ser válida y confiable. Esta escala puede ser utilizada por investigadores y profesionales de la salud que estudian las consecuencias psicológicas de la obesidad

Evolutionary optimization of service times in interactive voice response systems

A call center is a system used by companies to provide a number of services to customers, which may vary from providing simple information to gathering and dealing with complaints or more complex transactions. The design of this kind of system is an important task, since the trend is that companies and institutions choose call centers as the primary option for customer relationship management. This paper presents an evolutionary algorithm based on Dandelion encoding to obtain near-optimal service trees which represent the structure of the desired call center. We introduce several modifications to the original Dandelion encoding in order to adapt it to the specific problem of service tree design. Two search space size reduction procedures improve the performance of the algorithm. Systematic experiments have been tackled in order to show the performance of our approach: first, we tackle different synthetic instances, where we discuss and analyze several aspects of the proposed evolutionary algorithm, and second, we tackle a real application, the design of the call center of an Italian telecommunications company. In all the experiments carried out we compare our approach with a lower bound for the problem based on information theory, and also with the results of a Huffman algorithm we have used for reference

Surface-Parallel Sensor Orientation for Assessing Energy Balance Components on Mountain Slopes

The consistency of eddy-covariance measurements is often evaluated in terms of the degree of energy balance closure. Even over sloping terrain, instrumentation for measuring energy balance components is commonly installed horizontally, i.e. perpendicular to the geo-potential gradient. Subsequently, turbulent fluxes of sensible and latent heat are rotated perpendicular to the mean streamlines using tilt-correction algorithms. However, net radiation (Rn) and soil heat fluxes (G) are treated differently, and typically only Rn is corrected to account for slope. With an applied case study, we show and argue several advantages of installing sensors surface-parallel to measure surface-normal Rn and G. For a 17 % south-west-facing slope, our results show that horizontal installation results in hysteresis in the energy balance closure and errors of up to 25 %. Finally, we propose an approximation to estimate the surface-normal Rn, when only vertical Rn measurements are available.Andalusia Regional Government through projects P12RNM-2409Andalusia Regional Government through projects P10-RNM-6299Spanish Ministry of Economy and Competitiveness though projects CGL2010-18782, CGL2014-52838-C2-1-R (GEISpain) and CGL2013-45410-REuropean Community’s Seventh Framework Programme through INFRA-2010-1.1.16-262254 (ACTRIS),INFRA-2011-1-284274 (InGOS) and PEOPLE-2013-IOF-625988 (DIESEL) project

A Review of Classification Problems and Algorithms in Renewable Energy Applications

Classification problems and their corresponding solving approaches constitute one of the fields of machine learning. The application of classification schemes in Renewable Energy (RE) has gained significant attention in the last few years, contributing to the deployment, management and optimization of RE systems. The main objective of this paper is to review the most important classification algorithms applied to RE problems, including both classical and novel algorithms. The paper also provides a comprehensive literature review and discussion on different classification techniques in specific RE problems, including wind speed/power prediction, fault diagnosis in RE systems, power quality disturbance classification and other applications in alternative RE systems. In this way, the paper describes classification techniques and metrics applied to RE problems, thus being useful both for researchers dealing with this kind of problem and for practitioners of the field