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Machine Learning-based USD/PKR Exchange Rate Forecasting Using Sentiment Analysis of Twitter Data

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Computers, Materials & Continua 2021年第6期67卷 3451-3461页

作者： Samreen Naeem Wali Khan Mashwani Aqib Ali M.Irfan Uddin Marwan Mahmoud Farrukh Jamal Christophe Chesneau Department of Computer Science&IT Glim Institute of Modern StudiesBahawalpur63100Pakistan Institute of Numerical Sciences Kohat University of Science&TechnologyKohat26000Pakistan Department of Computer Science Concordia College BahawalpurBahawalpur63100Pakistan Institute of Computing Kohat University of Science and TechnologyKohat26000Pakistan Faculty of Applied Studies King Abdulaziz UniversityJeddah21577Saudi Arabia Department of Statistics The Islamia University of BahawalpurBahawalpur63100Pakistan Department of Mathematics Universitéde CaenLMNOCampus IIScience 3Caen14032France

This study proposes an approach based on machine learning to forecast currency exchange rates by applying sentiment analysis to messages on Twitter(called tweets).A dataset of the exchange rates between the United States Dollar(USD)and the Pakistani Rupee(PKR)was formed by collecting information from a forex website as well as a collection of tweets from the business community in Pakistan containing finance-related *** dataset was collected in raw form,and was subjected to natural language processing by way of data *** variable labeling was then applied to the standardized dataset,where the response variables were divided into two classes:“1”indicated an increase in the exchange rate and“−1”indicated a decrease in *** better represent the dataset,we used linear discriminant analysis and principal component analysis to visualize the data in three-dimensional vector *** that were obtained using a sampling approach were then used for data *** machine learning classifiers—the simple logistic classifier,the random forest,bagging,naïve Bayes,and the support vector machine—were applied to the optimized *** results show that the simple logistic classifier yielded the highest accuracy of 82.14%for the USD and the PKR exchange rates forecasting.

关键词： Machine learning exchange rate sentiment analysis linear discriminant analysis principal component analysis simple logistic

Status Report on Organo-Metallic Beams at GANIL

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Chinese Physics C 2007年第S1期31卷 85-89页

作者： P.Lehérissier C.Barué *** M.Dubois M.Dupuis J.L.Flambard P.A.Jaffres P.Jardin G.Gaubert N.Lecesne F.Lemagnen R.Leroy J.Y.Pacquet GANIL (Grand Accélérateur National d'Ions Lourds) Bd H.BecquerelBP 5502714076 CAEN Cedex 5France ENSI caen-LCMT-6 Bd Maréchal Juin 14050 CAEN CedexFrance

Previous experiments with organo-metallic compounds like ferrocene,nickelocene and magnesocene showed that a pure spectrum must be obtained on the residual gas mass analyser before running successfully on the ion *** collaboration with the chemistry department of the University of caen,LCMT-ENSI caen,the synthesis of these metallocene compounds has been studied to provide enriched isotopic compounds to GANIL’s *** chemical transformation yields were 90%,80% and 43%,***, chromocene,colbatocene and ruthenocene compounds have first been studied with a gas mass analyser and then successfully tested on the ECR 4M ion source at *** 15eμA of ^(51)V^(11+),20eμA of ^(52)Cr^(11+), 22eμA of 59Co^(11+),and 17eμA of ^(102)Ru^(11+) were *** comparison between the results obtained on the gas mass analyser and the ion beams provided by the source has allowed us to validate this method of determining whether or not an organo-metallic compound could be a candidate for running on our ECR ion *** the ECR ion sources are tuned and used alternately on the GANIL injectors,the available time for the tests is rare,so this method could be an alternative for the validation of new compounds.

关键词： organo-metallic ECRIS MIVOC

Bayesian Analysis in Partially Accelerated Life Tests for Weighted Lomax Distribution

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Computers, Materials & Continua 2021年第9期68卷 2859-2875页

作者： Rashad Bantan Amal S.Hassan Ehab Almetwally M.Elgarhy Farrukh Jamal Christophe Chesneau Mahmoud Elsehetry Deanship of Scientific Research King Abdulaziz UniversityJeddah21589Kingdom of Saudi Arabia Faculty of Graduate Studies for Statistical Research Cairo UniversityGiza12613Egypt Faculty of Business Administration Delta University of Science and TechnologyMansoura11152Egypt The Higher Institute of Commercial Sciences Al Mahalla Al Kubra31951AlgarbiaEgypt Department of Statistics The Islamia University of BahawalpurPunjab 63100Pakistan Department of Mathematics LMNOUniversity of CaenCaen14032France Deanship of Information Technology King Abdulaziz UniversityJeddah21589Kingdom of Saudi Arabia

Accelerated life testing has been widely used in product life testing experiments because it can quickly provide information on the lifetime distributions by testing products or materials at higher than basic conditional levels of stress,such as pressure,temperature,vibration,voltage,or load to induce early *** this paper,a step stress partially accelerated life test(SSPALT)is regarded under the progressive type-II censored data with random *** removals from the test are considered to have the binomial *** life times of the testing items are assumed to follow lengthbiased weighted Lomax *** maximum likelihood method is used for estimating the model parameters of length-biased weighted *** asymptotic confidence interval estimates of the model parameters are evaluated using the Fisher information *** Bayesian estimators cannot be obtained in the explicit form,so the Markov chain Monte Carlo method is employed to address this problem,which ensures both obtaining the Bayesian estimates as well as constructing the credible interval of the involved *** precision of the Bayesian estimates and the maximum likelihood estimates are compared by *** addition,to compare the performance of the considered confidence intervals for different parameter values and sample *** Bootstrap confidence intervals give more accurate results than the approximate confidence intervals since the lengths of the former are less than the lengths of latter,for different sample sizes,observed failures,and censoring schemes,in most ***,the percentile Bootstrap confidence intervals give more accurate results than Bootstrap-t since the lengths of the former are less than the lengths of latter for different sample sizes,observed failures,and censoring schemes,in most *** performance comparison is conducted by the experiments with real data.

关键词： Partially accelerated life testing progressive type-II censoring length-biased weighted Lomax Bayesian and bootstrap confidence intervals

Boron nitride nanotube growth via boron oxide assisted chemical vapor transport-deposition process using LiNO3 as a promoter

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Nano Research 2015年第6期8卷 2063-2072页

作者： Andrei T. Matveev Konstantin L. Firestein Alexander E. Steinman Andrey M. Kovalskii Oleg I. Lebedev Dmitry V. Shtansky Dmitri Golberg National University of Science and Technology 'MISIS' Leninskiy prospect 4 Moscow 119049 Russia CRISMAT UMR 6508 CNRS-ENSICAEN 6BdMarechalJuin Caen 14050 France Institute for Materials Science (NIMS) Namiki 1 Ibaraki Tsukuba 3050044 Japan

High-purity straight and discrete multiwalled boron nitride nanotubes （BNNTs） were grown via a boron oxide vapor reaction with ammonia using LiNO3 as a promoter. Only a trace amount of boron oxide was detected as an impurity in the BNNTs by energy-dispersive X-ray （EDX） and Raman spectroscopies. Boron oxide vapor was generated from a mixture of B, FeO, and MgO powders heated to 1,150 ℃, and it was transported to the reaction zone by flowing ammonia. Lithium nitrate was applied to the upper side of a BN bar from a water solution. The bar was placed along a temperature gradient zone in a horizontal tubular furnace. BNNTs with average diameters of 30-50 nm were mostly observed in a temperature range of 1,280-1,320 ℃. At higher temperatures, curled polycrystalline BN fibers appeared. Above 1,320 ℃, the number of BNNTs drastically decreased, whereas the quantity and diameter of the fibers increased. The mechanism of BNNT and fiber growth is proposed and discussed.

关键词： boron nit-ride nanotubes CVD lithium nitrate lithium borate BNNT growth mechanism

FTIR Investigation of C-implanted Crystalline SiO2 after 950 MeV Pb-ion irradiation

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IMP & HIRFL Annual Report 2005年 59-60页

作者： A. Benyagoub M. Toulemonde CIRIL BP513314070 Caen Cedex 05France

Crystalline SiO2(c-SiO2) samples were firstly implanted at room temperature (RT) with 120 keV Cions and then irradiated at RT with 950 MeV Pb ions. The C-ion irradiation experiments were performed on the 200 kV heavy ion implanter of IMP and the selected implantation doses are 2. 0×1017 , 5. 0×1017, 8. 6×1017 and 1. 2×1017C/cm2. The Pb ion irradiation was carried out at the IRASME (CIRIL-GANIL, caen) and the irradiation fluencies are 5.0×1011,1. 0×1012 and 1..0×1012 Pb/cm2 , respectively. The chemical bonds formation in the samples was investigated by using a Spectrum GX IR spectroscopy.

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Phonon engineering significantly reducing thermal conductivity of thermoelectric materials: a review

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Rare Metals 2023年第9期42卷 2825-2839页

作者： Chuan-Dong Zhou Bo Liang Wen-Jie Huang Jacques-Guillaume Noudem Xiao-Jian Tan Jun Jiang State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao066004China ENSIcaen UNICEFCNRSCRISMATNormandie UniversityNormandie14000CaenFrance Ningbo Institute of Materials Technology and Engineering Chinese Academy of SciencesNingbo315201China

Lattice thermal conductivity, κL, is a fundamental parameter for evaluating the performance of thermoelectric materials. However, the predicted value of κL based on the Debye dispersion model is often overestimated compared with the experimentally determined *** researchers have attempted to modify the theoretical model and have sought more reliable results. In this review,the recent progress in the study of phonon dispersion models is summarized and we propose that the lattice thermal conductivity can be most accurately determined by using the modified sinusoidal phonon dispersion ***, experimental methods that have the potential to reduce a thermoelectric material's κLare reviewed, for example, methods that generate standing waves or anharmonic lattice vibrations. A high concentration of standing waves and anharmonic lattice vibrations can effectively suppress excessive κL. Finally, this review presents the challenges of sinusoidal phonon dispersion when applied to real materials, which are often complicated and therefore time-consuming, especially when dealing with material defects.

关键词： Thermoelectric Lattice thermal conductivity Sinusoidal phonon dispersion model Standing wave Anharmonicity

Fixed points of n-valued maps on surfaces and the Wecken property a configuration space approach

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Science China Mathematics 2017年第9期60卷 1561-1574页

作者： GONCALVES Daciberg Lima GUASCHI John Departamento de Matemdtica&IME Universidade de Sao PauloSdo Paulo 05508-090Brazil Laboratoire de Mathematiques Nicolas Oresme UMR CNRS 6139 UNICAENNormandie UniversiteCS 1403214032 Caen Cedex 5France

Abstract In this paper, we explore the fixed point theory of n-vaiued maps using configuration spaces and braid groups, focusing on two fundamental problems, the Wecken property, and the computation of the Nielsen number. We show that the projective plane （resp. the 2-sphere S2） has the Wecken property for n-valued maps for all n ∈N （resp. all n ≥ 3）. In the case n = 2 and S2, we prove a partial result about the Wecken property. We then describe the Nielsen number of a non-split n-valued map φ ： X → X of an orientable, compact manifold without boundary in terms of the Nielsen coincidence numbers of a certain finite covering q：）→ X with a subset of the coordinate maps of a lift of the n-valued split map → q ： →X.

关键词： multivalued maps fixed points Wecken property Nielsen numbers braids configuration space

Glyphosate Exposure in a Farmer’s Family

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Journal of Environmental Protection 2012年第9期3卷 1001-1003页

作者： Robin Mesnage Christian Moesch Rozenn Le Grand Guillaume Lauthier Joel Spiroux de Vendomois Steeve Gress Gilles-Eric Seralini Network on Risks Quality and Sustainable Environment MRSH-CNRSInstitute of BiologyUniversity of CaenCaenFrance CRIIGEN ParisFrance Pharmacology and Toxicology Department University Hospital of LimogesLimogesFrance

We tested the presence of glyphosate in the urines of a farmer who sprayed a glyphosate based herbicide on his land, and in his family, as his children were born with birth defects that could be due to or promoted by pesticides. Glyphosate residues were measured in urines a day before, during, and two days after spraying, by liquid chromatography-linear ion trap mass spectrometry. Glyphosate reached a peak of 9.5 μg/L in the farmer after spraying, and 2 μg/L were found in him and in one of his children living at a distance from the field, two days after the pulverization. Oral or dermal absorptions could explain the differential pesticide excretions, even in family members at a distance from the fields. A more detailed following of agricultural practices and family exposures should be advocated together with information and recommendations.

关键词： Glyphosate Exposure Pesticides Birth Defects Agricultural Practices

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Asian Journal of Andrology 2008年第2期10卷 177-187页

作者： Khaled Hamden Dorothee Silandre Christelle Delalande Abdefattah El Feki Serge Carreau Animal Ecophysiology Faculty of Sciences Sfax-3018 Tunisia USC 20061NRA- EA 2608 Biochemistry Caen-14032 France

Aim： To examine the effects on rat aging of caloric restriction （CR1） and undernutrition （CR2） on the body and on testicular weights, on two enzymatic antioxidants （superoxide dismutase and catalase）, on lipid peroxidation and on the expression of testicular aromatase and estrogen receptors （ER）. Methods： CR was initiated in 1-month-old rats and carried on until the age of 18 months. Results： In control and CR2 rats an age-related decrease of the aromatase and of ER （α and β） gene expression was observed; in parallel a diminution of testicular weights, and of the total number and motility of epididymal spermatozo was recorded. In addition, aging in control and CR2 rats was accompartied by a significant decrease in testicular superoxide dismutase, catalase activities, and an increase in lipid peroxidation level （thiobarbituric acid reactive substance）, associated with alterations of spermatogenesis. Conversely, caloric restriction-treatment exerted a protective effect and all the parameters were less affected by aging. Conclusion： These results indicate that during aging, a low caloric diet （not undernutrition） is beneficial for spermatogenesis and likely improves the protection of the cells via an increase of the cellular antioxidant defense system in which aromatase/ ER could play a role. （Asian J Andro12008 Mar; 10： 177-187）

关键词： aging low caloric diet rat testis aromatase estrogen receptors antioxidants