ARTICLE | doi:10.20944/preprints202204.0227.v1
Subject: Computer Science And Mathematics, Computer Science Keywords: chess; elo; evaluation; equal play; handicap
Online: 26 April 2022 (04:41:40 CEST)
Chess is an interesting game for artificial intelligence research and an entertaining hobby and sport for a growing number of people. However, humans differ greatly in their ability to play. Typically, the Elo rating is used to determine a player's skill and to predict who will win. When differences in Elo are too great the weaker player is almost guaranteed to lose. While on one hand, the Elo rating allows players to be matched to equally well-playing opponents, it also to some degree restricts the games to be played between equally strong opponents since otherwise the result is known beforehand. Here a handicap system where stronger players remove pieces at the start of the game is evaluated. Specifically, the effect each removed piece or combination of pieces have on a player. Interestingly, pieces do not always reduce the Elo of a player by a predefined amount, but their effect depends strongly on the player's current Elo. The results presented here are from playing the computer engine Stockfish because data about humans playing this scheme is limited. However, the results make direct predictions about the effect of piece removal on Elo.
ARTICLE | doi:10.20944/preprints202107.0316.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Randomized Controlled Trial; Equal Group Size; Nursing; Allocation Bias; Effect Size
Online: 14 July 2021 (10:49:38 CEST)
The manipulation of participant allocation in randomized controlled trials to achieve equal groups sizes may introduce allocation bias potentially leading to larger treatment effect estimates. This study aimed to estimate the proportion of nursing trials that have precisely equal group sizes and examine if there was an association with trial outcome. Data were extracted from a sample of 148 randomized controlled trials published in nursing science journals in 2017. One hundred trials (68%) had precisely equal group sizes. Respectively, a positive outcome was reported in 70% and 58% of trials with equal/unequal groups. Trials from Asia were more likely to have equal group sizes than those from the rest of the world. Most trials reported a sample size calculation (n=105, 71%). In a third of trials (n=36, 34%), the number of participants recruited precisely matched the requirement of the sample size calculation; this was significantly more common in studies with equal group sizes. The high number of nursing trials with equal groups may suggest nurses con-ducting clinical trials are manipulating participant allocation to ensure equal group size increasing the risk of bias.
ARTICLE | doi:10.20944/preprints201812.0190.v1
Subject: Computer Science And Mathematics, Applied Mathematics Keywords: Space-time fractional Equal-Width equations; Conformable derivative; Hyperbolic function approach; Exact soliton solutions
Online: 17 December 2018 (10:47:03 CET)
Exact and soliton type solutions have great importance in propagation of surface waves, fluid dynamics, optics, and many other elds of nonlinear sciences. In this study, the explicit and exact soliton type solutions for two space-time fractional Equal- Width (FEW) equations with conformable derivative are procured via the hyperbolic function approach. The wave type solutions are represented in some hyperbolic and trigonometric functions.
ARTICLE | doi:10.20944/preprints201712.0143.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: equal-channel angular pressing; ECAP; shear band; matrix band; kinematic hardening; FEM; strain localization
Online: 20 December 2017 (10:01:31 CET)
Equal-Channel Angular Pressing (ECAP) is a method used to introduce severe plastic deformation into a metallic billet without changing its geometry. In special cases strain localization occurs and a pattern consisting of regions with high and low deformation (so-called shear and matrix bands) can emerge. This paper studies this phenomenon numerically adopting two-dimensional finite element simulations of one ECAP pass. The mechanical behavior of aluminum is modeled using phenomenological plasticity theory with isotropic or kinematic hardening. The effects of the two different strain hardening types are investigated numerically by systematic parameter studies: While isotropic hardening only causes minor fluctuations in the plastic strain fields, a material with high initial hardening rate and sufficient strain hardening capacity can exhibit pronounced localized deformation after ECAP. The corresponding finite element simulation results show a regular pattern of shear and matrix bands. This result is confirmed experimentally by ECAP-processing of AA6060 material in a severely cold worked condition, where microstructural analysis also reveals the formation of shear and matrix bands. Excellent agreement is found between the experimental and numerical results in terms of shear and matrix band width and length scale. The simulations provide additional insights regarding the evolution of the strain and stress states in shear and matrix bands.
ARTICLE | doi:10.20944/preprints202305.0783.v1
Subject: Medicine And Pharmacology, Epidemiology And Infectious Diseases Keywords: Candida; Candidemia; invasive candidiasis; Candida auris; non-albicans candida; COVID-19; antifungal susceptibility; Lebanon; Arab world; EQUAL score
Online: 11 May 2023 (04:37:02 CEST)
Invasive fungal infections, notably candidemia, have been associated with COVID-19. The epidemiology of candidemia has significantly changed during the COVID-19 pandemic. We aim to identify the microbiological profile, resistance rates, and outcomes of COVID-19 associated candidemia (CAC) compared to patients with candidemia not associated with COVID-19. We retrospectively collected data on patients with candidemia admitted to the American University of Beirut Medical Center between 2004 and 2022. We compared the epidemiology of candidemia during and prior to the COVID-19 pandemic. Additionally, we compared the outcomes of critically ill patients with CAC to those with candidemia without COVID-19 from March 2020 till March 2022. Among 245 candidemia episodes, 156 occurred prior to the pandemic and 89 during the pandemic. Of the latter, 39 (43.8%) were CAC, most of which (82%) were reported from intensive care units (ICU). Non-albicans Candida (NAC) spp. were predominant throughout the study period (67.7%). Candida auris infection was the most common cause of NAC spp. in CAC. C. glabrata had decreased susceptibility rates to fluconazole and caspofungin during the pandemic period (46.1% and 38.4% respectively). Mortality rate in the overall ICU population during the pandemic was 76.6%, much higher than the previously reported mortality of candidemia from previous studies at our center. There was no significant difference in 30-day mortality between CAC and non-CAC (75.0% vs 78.1%; P =0.76). Performing ophthalmic examination (P = 0.002), CVC removal during the 48 hours following the candidemia (P = 0.008) and identifying the Candida spp. (P = 0.028) were significantly associated with a lower case-fatality rate. The epidemiology of candidemia has been significantly affected by the COVID-19 pandemic at our center. Rigorous infection control measures and proper antifungal stewardship are essential to combat highly resistant species like C. auris.
ARTICLE | doi:10.20944/preprints202306.0173.v1
Subject: Engineering, Mechanical Engineering Keywords: Pulp cell; Periodontal cell; Micro-Arc Oxidation (MAO), Sever Plastic deformation (SPD), Equal Channel Angular Pressing (ECAP), AlamarBlue; ELISA; trypsin
Online: 2 June 2023 (10:01:53 CEST)
Keywords: Pulp cell, Periodontal cell, Micro-Arc Oxidation (MAO), Sever Plastic deformation (SPD), Equal Channel Angular Pressing (ECAP), AlamarBlue, ELISA, trypsin
ARTICLE | doi:10.20944/preprints201802.0141.v1
Subject: Computer Science And Mathematics, Mathematics Keywords: Ansatz method; fractional modified Korteweg–de Vries Equation; fractional modified Equal Width Equation; fractional Benney–Luke Equation; Conformable fractional derivative
Online: 22 February 2018 (10:45:02 CET)
The space time fractional Korteweg-de Vries equation, modified Equal Width equation and Benney-Luke Equations are solved by using simple hyperbolic tangent Ansatz method. A simple compatible wave transformation in one dimension is employed to reduce the governing equations to integer ordered ODEs. Then, the ansatz approximation is used to derive exact solutions. Some illustrative examples are presented for some particular choices of parameters and derivative orders.
ARTICLE | doi:10.20944/preprints202301.0501.v1
Subject: Chemistry And Materials Science, Metals, Alloys And Metallurgy Keywords: titanium alloy; ultrafine-grained microstructure; equal channel angular pressing; spark plasma sintering; diffusion welding; corrosion; hat salt corrosion; diffusion; grain boundary.
Online: 27 January 2023 (10:29:04 CET)
A diffusion welding of coarse-grained and ultrafine-grained (UFG) specimens of titanium near-α alloy Ti-5Al-2V used in nuclear power engineering was made by Spark Plasma Sintering. The failure of the welded specimens in the conditions of hot salt corrosion and of electrochemical corrosion were shown to have preferentially intercrystalline character. In the case of presence of macrodefects, crevice corrosion of the welded joints was observed. The resistance of the alloys against the intercrystalline corrosion was found to be determined by the concentration of vanadium at the titanium grain boundaries, by the size and volume fraction of the β-phase particles and by the presence of micro- and macropores in the welded joints. The specimens of the welded joints of the UFG alloy have higher hardness, hot salt corrosion resistance and the electrochemical corrosion.