1,311 research outputs found

    Proposed Framework for complete analysis when teaching Regression in Supervised Machine Learning

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    It could be challenging for students and instructors to piece together a different regression concepts to coherently perform a complete data analysis. I propose using a framework which reinforces the detailed steps towards regression in Supervised Machine Learning, to be reiterated throughout the coursework. This is based on past literatures supporting reiterated and systematic teaching. Such could also mitigate the applicable and visible educational gap between Novices and Experts in teaching such concepts to Primary and Secondary School students.Comment: 3 pages, 1 table, 0 figure

    A Data Analysis of the World Happiness Index and its Relation to the North-South Divide

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    In this document, we perform a detailed data analysis on the World Happiness Report with its relation to the socio-economic North-South Divide. In order to do so, we perform some extensive data cleaning and analysis before querying on the World Happiness Report. Our results based on Hypothesis Testing determines the happiness of the Global North is greater than that of the Global South. Furthermore, our queries show that the mean happiness score for the Global North significantly outweighing that of the South. Likewise, the 10 \u27Happiest\u27 nations all belong to the Global North whereas the 10 \u27least happy\u27 nations belong to the Global South

    Repeat Buying Behavior for Ornamental Plants: A Consumer Profile

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    The main objective of this research was to study what stimulates repeat buying behavior for ornamental plants by segmenting consumer demographics and other important variables in the purchasing decision for ornamental plants. Specifically, we looked at the number of transactions per month as a function of the purpose of the purchase. Consumer’s behavioral and socio-demographic characteristics that are more likely to influence the number of ornamental transactions were also identified.Green Industry, flower demand, consumer preferences, Consumer/Household Economics, Marketing, M31, R22,

    Experimental Investigation of Supercooled Water Droplet Breakup near the Leading Edge of an Airfoil

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    This paper presents the results of an experimental study on supercooled droplet deformation and breakup near the leading edge of an airfoil. The results are compared to prior room-temperature droplet deformation results to explore the effects of droplet supercooling. The experiments were conducted in the Adverse Environment Rotor Test Stand at The Pennsylvania State University. An airfoil model placed at the end of the rotor blades mounted onto the hub in the Adverse Environment Rotor Test Stand chamber was moved at speeds ranging between 50 and 80 ms. The temperature of the chamber was 20C. A monotonic droplet generator was used to produce droplets that fell perpendicular to the airfoil path. High-speed imaging was employed to observe the interaction between the droplets and the airfoil. Cases with equal slip and initial velocity were selected for the two environmental conditions. The airfoil velocity was 60 ms, and the slip velocity for both sets of data was 40 ms. The deformation of the weakly supercooled and warm droplets did not present different trends. The similar behavior for both conditions indicates that water supercooling has no effect on particle deformation for the range of supercooling of the droplets tested and the selected impact velocity

    Mechanism of Supercooled Water Droplet Breakup near the Leading Edge of an Airfoil

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    This work presents the results of an experimental study on supercooled droplet deformation and breakup near the leading edge of an airfoil. The results are compared to prior room temperature droplet deformation results to explore the effects of droplet supercooling. The experiments were conducted in the Adverse Environment Rotor Test Stand (AERTS) at The Pennsylvania State University. An airfoil model placed at the end of the rotor blades mounted onto the hub in the AERTS chamber was moved at speeds ranging between 50 and 80 m/sec. The temperature of the chamber was set at -20C. A monotonic droplet generator was used to produce droplets that fell from above, perpendicular to the path of the airfoil. The supercooled state of the droplets was determined by measurement of the temperature of the drops at various locations below the droplet generator exit. A temperature prediction code was also used to estimate the temperature of the droplets based on vertical velocity and the distance traveled by droplets from the droplet generator to the airfoil stagnation line. High speed imaging was employed to observe the interaction between the droplets and the airfoil. The high speed imaging provided droplet deformation information as the droplet approached the airfoil near the stagnation line. A tracking software program was used to measure the horizontal and vertical displacement of the droplet against time. It was demonstrated that to compare the effects of water supercooling on droplet deformation, the ratio of the slip velocity and the initial droplet velocity must be equal. A case with equal slip velocity to initial velocity ratios was selected for room temperature and supercooled droplet conditions. The airfoil velocity was 60 m/s and the slip velocity for both sets of data was 40 m/s. In these cases, the deformation of the weakly supercooled and warm droplets did not present different trends. The similar behavior for both environmental conditions indicates that water supercooling has no effect on particle deformation for the limited range of the weak supercooling of the droplets tested and the selected impact velocity. The assumption of a constant surface tension value was further supported by the equal trend of the Bond number obtained for supercooled and room temperature droplets

    Extreme-ultraviolet structured beams via high harmonic generation

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    Funding European Research Council (851201); Ministerio de Ciencia de Innovación y Universidades, Agencia Estatal de Investigaci ́on and European Social Fund (PID2019106910GB-I00, RYC-2017-22745); Junta de Castilla y León and FEDER Funds (SA287P18); Université ParisSaclay (2012-0333TOASIS, 50110000724-OPTX, PhOM REC-2019-074-MAOHAm); Conseil Régional, I ˆle-de-France (501100003990); Barcelona Supercomputing Center (FI2020-3-0013).Vigorous efforts to harness the topological properties of light have enabled a multitude of novel applications. Translating the applications of structured light to higher spatial and temporal resolutions mandates their controlled generation, manipulation, and thorough characterization in the short-wavelength regime. Here, we resort to high-order harmonic generation (HHG) in a noble gas to upconvert near-infrared (IR) vector, vortex, and vector-vortex driving beams that are tailored, respectively, in their spin angular momentum (SAM), orbital angular momentum (OAM), and simultaneously in their SAM and OAM. We show that HHG enables the controlled generation of extreme-ultraviolet (EUV) vector beams exhibiting various spatially dependent polarization distributions, or EUV vortex beams with a highly twisted phase. Moreover, we demonstrate the generation of EUV vector-vortex beams (VVB) bearing combined characteristics of vector and vortex beams. We rely on EUV wavefront sensing to unambiguously affirm the topological charge scaling of the HHG beams with the harmonic order. Interestingly, our work shows that HHG allows for a synchronous controlled manipulation of SAM and OAM. These EUV structured beams bring in the promising scenario of their applications at nanometric spatial and sub-femtosecond temporal resolutions using a table-top harmonic source

    Attention-driven imitation in consumer reviews

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    Product reviews on e-commerce platforms can have a pronounced effect on consumers' decisions. Less is known, however, whether the reviews written by others can shape a person's own written opinion of a product. We hypothesized that people who compose reviews on digital storefronts will try to imitate successful reviews, such that their content will show similarity with other reviews displayed at the time of writing. More specifically, we predicted that reviews will be more semantically similar to the most successful, salient, and readily accessible reviews written by others. To investigate this hypothesis, we extracted over 3 million reviews from a major online distribution platform and traced the reviews that were displayed at the time when each review was being composed. Using word embeddings from a pre-trained language model, we quantified the semantic similarity between a given review and other reviews that were visible (or not) to a user. We found that reviewers imitate the most helpful reviews written by others, especially those that are visually salient. Their reviews, in turn, gather more helpfulness ratings in the future, leading to a cascade of similar reviews. Our findings suggest that the default sorting and display format of reviews on online platforms will have a pronounced effect on the style and content of new reviews
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