Gradient Research Papers - Academia.edu (original) (raw)

This study focuses on how textbook signatures can be formulated to represent similarities and differences in mathematics textbooks across different countries. In this paper, we examine the teaching of gradient (Grade 8) in Germany,... more

This study focuses on how textbook signatures can be formulated to represent similarities and differences in mathematics textbooks across different countries. In this paper, we examine the teaching of gradient (Grade 8) in Germany, Singapore, and South Korea by characterising the textbooks in terms of contextual (educational factors), content, and instructional variables. Findings suggest an alignment between these variables and the respective curriculum emphases.

The numerical methods employed in the solution of many scientific computing problems require the computation of derivatives of a function~: R “+ Rm. ADIFOR(Automatic Differentiation In FORtran) is a source transformation tool that accepts... more

The numerical methods employed in the solution of many scientific computing problems require the computation of derivatives of a function~: R “+ Rm. ADIFOR(Automatic Differentiation In FORtran) is a source transformation tool that accepts Fortran 77 code for ...

In the cyber era, Machine Learning (ML) has provided us with the solutions to these problems with the implementation of Gradient Boosting Machines (GBM). We have ample algorithms to choose from to do gradient boosting for our training... more

In the cyber era, Machine Learning (ML) has provided us with the solutions to these problems with the implementation of Gradient Boosting Machines (GBM). We have ample algorithms to choose from to do gradient boosting for our training data but still, we encounter different issues like poor accuracy, high loss, large variance in the result. Here, we are going to introduce you to a state of the art machine learning algorithm XGBoost built by Tianqi Chen, that will not only overcome the issues but also perform exceptionally well for regression and classification problems. This blog will help you discover the insights, techniques, and skills with XGBoost that you can then bring to your machine learning projects.
eXtreme Gradient Boosting (XGBoost) is a scalable and improved version of the gradient boosting algorithm (terminology alert) designed for efficacy, computational speed and model performance. It is an open-source library and a part of the Distributed Machine Learning Community. XGBoost is a perfect blend of software and hardware capabilities designed to enhance existing boosting techniques with accuracy in the shortest amount of time. Here’s a quick look at an objective benchmark comparison of XGBoost with other gradient boosting algorithms trained on random forest with 500 trees, performed by Szilard Pafka.

In this thesis I use carabid beetles (Coleoptera, Carabidae) and vascular plants to investigate the ecological effects of urbanization on forested and dry meadow habitats in the city of Helsinki, Finland. I also investigate factors that... more

In this thesis I use carabid beetles (Coleoptera, Carabidae) and vascular plants to investigate the ecological effects of urbanization on forested and dry meadow habitats in the city of Helsinki, Finland. I also investigate factors that affect species
diversity and the occurrence of rare and sensitive species in particular, in order to draft recommendations for habitat management for the enhancement of urban biodiversity. Urbanization gradient analyses are conducted using multivariate ordination analyses to elucidate assemblage level responses, ANOVA is applied to determine the assemblage level response of spruce forest carabid assemblages and GLMM is used to model individual species responses. The results suggest that, in contrast to Gray’s suggestion, Preston’s log-normal does not accurately describe the species distributions of carabid beetles in the studied habitats but rather they follow the predictions of Fisher’s log series and Hubbell’s unified neutral theory. I conclude that fragmentation, isolation and homogenization are the main problems regarding maintenance of urban biodiversity, and that biodiversity strategies should focus on the conservation of stenotopic species. In particular, habitats and ecologically important microhabitat conditions should be retained in as large and contiguous a form as possible. For instance, spruce forest habitats need to be managed to maintain shady, cool and moist conditions and dry meadows should be mown late in the season and the cut vegetation removed. Additionally, supplementation of habitat
networks should be implemented, by habitat restoration and habitat creation, such as the construction of dry meadows on landfills and noise abatement banks.

An HPLC method was developed for the simultaneous determination of seven water-soluble vitamins, viz. thiamine, riboflavin, nicotinic acid, nicotinamide, pyridoxine, cyanocobalamin, and folic acid, in multivitamin pharmaceutical... more

An HPLC method was developed for the simultaneous determination of seven water-soluble vitamins, viz. thiamine, riboflavin, nicotinic acid, nicotinamide, pyridoxine, cyanocobalamin, and folic acid, in multivitamin pharmaceutical formulations and biological fluids (blood serum and urine). Separation was achieved at ambient temperature on a Phenomenex Luna C18 (150×4.6 mm) analytical column. Gradient elution was performed starting at a 99 : 1 A:B v/v composition, where A: 0.05 M CH3COONH4/CH3OH (99/1) and B: H2O/CH3OH (50/50), at a flow rate of 0.8 mL/min. After a 4-min isocratic elution the composition was changed to 100% of B in 18 min and elution continued isocratically for 8 min. Detection was performed with a photodiode array detector at 280 nm. Each vitamin was quantitatively determined at its maximum wavelength. Spectral comparison was used for peak identification in real samples. Detection limits were in the range of 1.6–3.4 ng, per 20-μL injection, while linearity held up to 25 ng/μL. Accuracy, intra-day repeatability (n = 6), and inter-day precision (n = 7) were found to be satisfactory. Theobromine (2 ng/μL) was used as internal standard. Sample preparation of biological fluids was performed by SPE on Supelclean LC-18 cartridges with methanol-water 85/15 v/v as eluent. Extraction recoveries from biological matrices ranged from 84.6% to 103.0%.

Mono-and double-layer porous scaffolds were successfully fabricated using ball-milled agglomerates of Ti and Ti–10Nb–3Mo alloy. For selectively controlling the level of porosity and pore size, the agglomerates were sieved into two... more

Mono-and double-layer porous scaffolds were successfully fabricated using ball-milled agglomerates of Ti and Ti–10Nb–3Mo alloy. For selectively controlling the level of porosity and pore size, the agglomerates were sieved into two different size fractions of 100–300 μm and 300–500 μm. Compressive mechanical properties were measured on a series of cylindrical sintered compacts with different ratios of solid core diameter to porous layer width. The graded porous scaffolds exhibited stress–strain curves typical for metallic foams with a defined plateau region after yielding. The compressive strengths and elastic moduli ranged from 300 to 700 MPa and 14 to 55 GPa, respectively, depending on the core diameter and the material used. The obtained properties make these materials suitable for load-bearing implant applications. Crown

The work deals with the confrontation of two approaches in vegetation science, which already had their origins at the beginning of the past century: gradient analysis and classification of communities. We tested whether samples are... more

The work deals with the confrontation of two approaches in vegetation science, which already had their origins at the beginning of the past century: gradient analysis and classification of communities. We tested whether samples are arranged along gradients according to the individualistic or the integrative concept. We studied gradients in several case studies – successional, altitudinal, gradient of human impact, phenological, macroecological, (phyto)geographical – and tried to detect the main gradient (by direct or indirect ordination methods) and arrange the plant assemblages along the gradient. We then applied different classification methods to test whether it is possible to detect discrete plant communities. We analyzed the secondary succession of birch forests in Slovenia, the process of autosuccession of Pinus brutia in Turkey, the altitudinal distribution of communities in rock crevices on silicate bedrock in Slovenia, the gradient of spruce planting in beech forest, the influence of the introduction of non-native tree species into forests, the macroecological and phenological development of weed vegetation in Europe, and the circum-Adriatic pattern of broadleaved ravine forests. The results show that, in most cases, the turnover of species composition along the gradient, according to the integrative concept, is due to species interactions. This enables us to detect and describe discrete plant communities in terms of the central European Braun-Blanquet method.

In this work, we have proposed enhancements that improve the performance of state-of-the-art facial emotion recognition (FER) systems. We believe that the changes in the positions of the fiducial points and the intensities capture the... more

In this work, we have proposed enhancements that improve the performance of state-of-the-art facial emotion recognition (FER) systems. We believe that the changes in the positions of the fiducial points and the intensities capture the crucial information regarding the emotion of a face image. We propose the inputting of the gradient and the Laplacian of the input image together with the original into a convolutional neural network (CNN). These modifications help the network learn additional information from the gradient and Laplacian of the images. However, as shown by our results, the CNN in the existing state-of-the-art models is not able to extract this information from the raw images. In addition, we employ spatial transformer network to add robustness to the system against rotation and scaling. We have performed a number of experiments on two well known datasets, namely KDEF and FERplus. Our approach enhances the already high performance of the state-of-the-art FER systems by 3...