AutoScor: An Automated System for Essay Questions Scoring

The automated scoring or evaluation for written student responses have been, and are still a highly interesting topic for both education and natural language processing, NLP, researchers alike. With the obvious motivation of the difficulties teachers face when marking or correcting open essay questions; the development of automatic scoring methods have recently received much attention. In this paper, we developed and compared number of NLP techniques that accomplish this task. The baseline for this study is based on a vector space model, VSM. Where after normalisation, the baseline-system represents each essay by a vector, and subsequently calculates its score using the cosine similarity between it and the vector of the model answer. This baseline is then compared with the improved model, which takes the document structure into account. To evaluate our system, we used real essays that submitted for computer science course. Each essay was independently scored by two teachers, which we used as our gold standard. The systems’ scoring was then compared to both teachers. A high emphasis was added to the evaluation when the two human assessors are in agreement. The systems’ results show a high and promising performance

Pore-GNN: A graph neural network-based framework for predicting flow properties of porous media from micro-CT images

This paper presents a hybrid deep learning framework that combines graph neural networks with convolutional neural networks to predict porous media properties. This approach capitalizes on the capabilities of pre-trained convolutional neural networks to extract n-dimensional feature vectors from processed three dimensional micro computed tomography porous media images obtained from seven different sandstone rock samples. Subsequently, two strategies for embedding the computed feature vectors into graphs were explored: extracting a single feature vector per sample (image) and treating each sample as a node in the training graph, and representing each sample as a graph by extracting a fixed number of feature vectors, which form the nodes of each training graph. Various types of graph convolutional layers were examined to evaluate the capabilities and limitations of spectral and spatial approaches. The dataset was divided into 70/20/10 for training, validation, and testing. The models were trained to predict the absolute permeability of porous media. Notably, the proposed architectures further reduce the selected objective loss function to values below 35 mD, with improvements in the coefficient of determination reaching 9%. Moreover, the generalizability of the networks was evaluated by testing their performance on unseen sandstone and carbonate rock samples that were not encountered during training. Finally, a sensitivity analysis is conducted to investigate the influence of various hyperparameters on the performance of the models. The findings highlight the potential of graph neural networks as promising deep learning-based alternatives for characterizing porous media properties. The proposed architectures efficiently predict the permeability, which is more than 500 times faster than that of numerical solvers.Document Type: Original articleCited as: Alzahrani, M. K., Shapoval, A., Chen, Z., Rahman, S. S. Pore-GNN: A graph neural network-based framework for predicting flow properties of porous media from micro-CT images. Advances in Geo-Energy Research, 2023, 10(1):39-55. https://doi.org/10.46690/ager.2023.10.0

Finding maximal bicliques in bipartite networks using node similarity

In real world complex networks, communities are usually both overlapping and hierarchical. A very important class of complex networks is the bipartite networks. Maximal bicliques are the strongest possible structural communities within them. Here we consider overlapping communities in bipartite networks and propose a method that detects an order-limited number of overlapping maximal bicliques covering the network. We formalise a measure of relative community strength by which communities can be categorised, compared and ranked. There are very few real bipartite datasets for which any external ground truth about overlapping communities is known. Here we test three such datasets. We categorise and rank the maximal biclique communities found by our algorithm according to our measure of strength. Deeper analysis of these bicliques shows they accord with ground truth and give useful additional insight. Based on this we suggest our algorithm can find true communities at the first level of a hierarchy. We add a heuristic merging stage to the maximal biclique algorithm to produce a second level hierarchy with fewer communities and obtain positive results when compared with other overlapping community detection algorithms for bipartite networks

Advances and limitations of increasing solar irradiance for concentrating photovoltaics thermal system

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record Concentrating photovoltaic-thermal (CPVT) technology harnesses solar energy by increasing the solar density upon cells using optical concentrators. CPVT systems are the focus of ongoing research and improvements to achieve the highest potential for energy harnessing and utilization. Increasing the concentration ratio for high energy generation raises many advances and limitations in the CPVT design. This article highlights the influence of the temperature with an increasing concentration ratio on CPVT components in terms of single-/multi-junction semiconductor materials, primary and secondary optical concentrator materials, and thermal receiver design. To achieve this, the theory of single- and multi-junction solar cell electrical characteristics (Voc,Isc,FF and η) is first explained to understand their dependence on the temperature and concentration ratio. An extensive literature review discussing the advantages, disadvantages, and potential of current CPVT research is given. This includes graphical and tabular summaries of many of the various CPVT design performances. In this review, it has been ascertained that higher concentration ratios raise the temperature at which the performance, operation and reliability of CPVT system are affected. Also, this review indicates that the temperature elevation of the CPVT components is significantly impacted by the optical configuration and their material types and reflectance. A thermal receiver is illustrated as three components: solar cell (heat source), heat spreader (substrates) and its different types, and cooling mechanism. In addition, the article addresses the thermomechanical stress created with intensified illumination, especially with secondary optics, where the optical materials and optical tolerance need to be carefully explored. The economic implications of a high concentration ratio level are briefly considered, addressing the reduction in system cost by enhancing the system efficiency. Suggestions are made throughout the review as to possible improvements in system performance.Saudi Arabia Culture Burea

Estimation of the performance limits of a concentrator solar cell coupled with a micro heat sink based on a finite element simulation

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordConcentrated photovoltaic (CPV) technology makes use of cheap optical elements to amplify the irradiance and focus it on small-sized solar cells enabling the extraction of higher amounts of electricity. However, increasing the solar concentration raises the temperature of the PV cell which can deter its performance and can also cause its failure. To combat this issue both active and passive cooling mechanisms are utilized for different types of CPV systems. In this study, we determine the limits of passive cooling systems and establish when an active cooling system is needed based on the recommended operating temperature of the solar cell. We investigate the temperature characteristics of the solar cells bonded to three different substrate materials under different solar concentrations. Results showed that cell temperature is linearly dependent on the concentration ratio and ambient temperature independent of the substrate material. Further, the integration of a micro-finned heatsink results in higher heat dissipation by 25.32%, 23.13%, and 22.24% in comparison with a flat plate heatsink for Direct Bonded Copper (DBC), Insulated Metal Substrate (IMS), and Silicon Wafer (Si wafer) substrates respectively. The low thermal resistance of the IMS substrate compared to the DBC and the Si wafer substrates result in the best thermal performance in terms of maintaining the cell temperature < 80 °C and allowing a wider range of high concentration ratio.Saudi Arabia Culture Burea

Signaling pathways regulated by Brassicaceae extract inhibit the formation of advanced glycated end products in rat brain

Background: The goal of this study was identification signaling molecules mediated the formation of AGEs in brain of rats injected with CdCl2 and the role of camel whey proteins and Brassicaceae extract on formation of AGEs in brain.Methods: Ninety male rats were randomly grouped into five groups; Normal control (GpI) and the other rats (groups II-V) were received a single dose of cadmium chloride i.p (5 μg/kg/b.w) for induction of neurodegeneration. Rats in groups III-V were treated daily with whey protein (1g/kg b.w) or Brassicaceae extract (1mg/kg b.w) or combined respectively for 12 weeks.Results: It was found that whey protein combined with Brassicaceae extract prevented the formation of AGEs and enhance the antioxidant activity compared with untreated group (p &lt;0.001). Serum tumor necrosis factor (TNF-α) and interleukine (IL-6) levels were significantly decreased (p&lt;0.01) in rats treated with whey protein and Brassicaceae extract formation compared with untreated. The combined treatment showed a better impact than individual ones (p&lt;0.001). The level of cAMP but not cGMP were lowered in combined treatment than individual (p&lt;0.01).Conclusion: it can be postulated that Whey protein + Brassicaceae extract formation could have potential benefits in the prevention of the onset and progression of neuropathy in patients.Keywords: Whey protein- Brassicaceae extract -neurodegeneration -rat

The Study of Learning Styles among Medical Students at Majmaah University, Saudi Arabia

The main objectives of this research were to detect types of learning styles (LS), time spending in studying, to know the relation with GPA, and to determine which LS is suitable with teaching style used in the College of Medicine at Majmaah University. The study was cross-sectional self-survey conducted among male and female medical students at College of Medicine at Majmaah city over 6 months. Cluster sampling was used and total participants were 194 students from College of Medicine (males & females). The data was collected using a designed questionnaire and analysis of data was performed by SPSS (V26).This study showed that majority of participants preferred the Visual learning (VL) style (27.79%), the second most used type was Kinesthetic (24.79%), and the least used type was Auditory (24.53%). It also showed that students who prefer VL style score more than students who prefer other learning styles. It was observed that the student who prefers kinesthetic style spent more time in the studying the more use of this type. In Conclusion, The study concluded that the majority of participants were preferred the VL style. It is also showed that student who prefers visual learning style score more than students who prefer other learning styles. It is important to increase awareness of students regarding types of their learning styles and teaching strategies in college during admission

Agronomical, physiological and molecular evaluation reveals superior salt-tolerance in bread wheat through salt-induced priming approach

Salt stress significantly limit wheat crop productivity worldwide. Exposure to non-lethal levels of salt stress, referred to as "salt-priming", allows plants to persist subsequent lethal conditions; the priming effect continues even after an extended salt stress-free period. This study attempted to evaluate the effectiveness of the salt-induced priming approach to cope with the toxic effects of long-term salinity stress in wheat. After 22 days of gradual salt acclamation to reach 250 mM NaCl, plants were recovered for eight days and finally shocked with 250 mM NaCl (priming+shock) for 7 days. After that, physiological parameters and gene expression of six salt-responsive genes were assessed. Additionally, 120 days after germination (at the end of the season), agronomic traits were recorded. Analysis of the agronomical traits revealed higher productivity in the salt-pretreated group (priming+shock) plants than the non-pretreated (shock only). Consistently, salt-pretreated plants maintained higher photosynthetic pigments level and decreased proline and MDA content than non-pretreated, suggesting enhanced salt tolerance. Moreover, salt-pretreated plants sustained high expressional levels of salt-responsive genes (TaNHX1, TaSOS1, TaSOS4, TaHKT1, TaHKT2, and TaAKT1) comparing with non-pretreated, indicating a vital role in ion homeostasis and conferring salt tolerance. Ultimately, this finding could facilitate novel smart approaches to improve wheat productivity under salt stress

Optical Losses and Durability of 4-Domed Optic for Concentrator Photovoltaics

This is the author accepted manuscript.The use of optical elements to focus light onto a smaller area of semiconductor material can enhance the cost effectiveness and electrical performance. Enabling ultrahigh concentration ratios for photovoltaic systems requires an optic bonded directly to the solar cell to further concentrate and homogenise the illumination, as well as to improve the acceptance angle. For many optical materials manufacture flaws are common, and difficult to prevent. An estimation of the effective external quantum efficiency of the receiver based on the material’s transmissivity tells us the effect of added absorptivity from manufacture defects. Evaluating the module under a solar simulator under various angles yields information on how scattered light changes the optic’s concentration ability. This study suggests sapphire has higher optical losses due to its higher refractive index compared to slygard184. Thus, the need for a higher refractive index material must be considered carefully and matched with anti-reflective coatings if needed. The effective concentration of slygard-184 notably suffers when flaws are present, dropping up to 48.2%. Further, the optimum angle is difficult to predict. Minor flaws could be deemed acceptable in performance when high acceptance angles are not the primary design requirement.Engineering and Physical Sciences Research Council (EPSRC