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Predicting an Optimal Virtual Data Model for Uniform Access to Large Heterogeneous Data

Data Intelligence 2024年第2期6卷 504-530页

作者： Chahrazed b.bachir belmehdi Abderrahmane Khiat Nabil Keskes LabRI-SbA Enterprise Information SystemsESI-SBA InstituteFraunhofer IAISAlgeriaGermany

The growth of generated data in the industry requires new efficient big data integration approaches for uniform data access by end-users to perform better business *** virtualization systems,including Ontology-based Data Access(ODbA)query data on-the-fly against the original data sources without any prior data *** approaches by design use a fixed model e.g.,TAbULAR as the only Virtual Data Model-a uniform schema built on-the-fly to load,transform,and join relevant *** other data models,such as gRAPH or DOCUMENT,are more flexible and,thus,can be more suitable for some common types of queries,such as join or nested *** queries are hard to predict because they depend on many criteria,such as query plan,data model,data size,and *** address the problem of selecting the optimal virtual data model for queries on large datasets,we present a new approach that(1)builds on the principal of ObDA to query and join large heterogeneous data in a distributed manner and(2)calls a deep learning method to predict the optimal virtual data model using features extracted from SPARQL ***-implementation of our approach currently leverages state-of-the-art big Data technologies,Apache-Spark and graphx,and implements two virtual data models,gRAPH and TAbULAR,and supports out-of-the-box five data sources models:property graph,document-based,e.g.,wide-columnar,relational,and tabular,stored in Neo4j,MongoDb,Cassandra,MySQL,and CSV *** experiments show that our approach is returning the optimal virtual model with an accuracy of 0.831,thus,a reduction in query execution time of over 40%for the tabular model selection and over 30%for the graph model selection.

关键词： Data Virtualization big Data ObDA Deep Learning

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Chemical leaching of an Indian bituminous coal and characterization of the products by vibrational spectroscopic techniques

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International Journal of Minerals,Metallurgy and Materials 2012年第4期19卷 279-283页

作者： b. Manoj A.g. Kunjomana Department of Physics Christ University Research and Development Centre Bharathiar University

High volatile bituminous coal .was demineralized by a chemical method. The vibrations of the ＂aromatics＂ structure of graphite, crystalline or non-crystalline, were observed in the spectra at the 1600 cm-1 region. The band at 1477 cm-1 is assigned as VR band, the band at 1392 cm-1 as VL band and the band at 1540 cm-1 as gR band. graphite structure remains after chemical leaching liberates oxygenated functional groups and mineral groups. The silicate bands between 1010 and 1100 cm-1 are active in the infrared （IR） spec^urn but inactive in the Raman spectrum. Absorption arising from C-H stretching in alkenes occurs in the region of 3000 to 2840 cm-~. Raman bands because of symmetric stretch of water molecules were also observed in the spectrum at 3250 cm-1 and 3450 cm-1. Scanning electron microscopy analy- sis revealed the presence of a graphite layer on the surface. Leaching of the sample with hydrofluoric acid decreases the mineral phase and increases the carbon content. The ash content is reduced by 84.5wt% with leaching from its initial value by mainly removing aluminum and silicate containing minerals.

关键词： bituminous coal characterization graphite leaching vibrational spectroscopy

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Experimental investigation of the normal spectral emissivity and other thermophysical properties of pulse-heated Ni-Ti and Au-Ni alloys into the liquid phase

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Rare Metals 2006年第5期25卷 592-596页

作者： b.Wilthan g.Pottlacher Institut für Experimentalphysik Technische Universitt GrazPetersgasse 168010 GrazAustria

In a previous paper it was shown that the normal spectral emissivity at 684.5 nm of a binary alloy can be lower than that of the pure constituent components. For the actual probes it was found that the observed values of normal spectral emissivity of the alloys are in between or higher than those of the pure constituent components. Experiments were conducted on the alloy systems Ni-Ti and Au-Ni. Their emissivity as well as electrical resistivity and enthalpy as a function of temperature is presented.

关键词： normal spectral emissivity thermophysical properties resistivity enthalpy pulse-heating Ni-Ti alloy Au-Ni alloy liquid phase

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Assessment of deterioration in RHA-concrete due to magnesium sulphate attack

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International Journal of Minerals,Metallurgy and Materials 2010年第6期17卷 691-696页

作者： g.A. Habeeb H.b. Mahmud N.b.A.A. Hamid Department of Civil Engineering Faculty of Engineering University of Malaya

The assessment of magnesium sulphate attack on concretes containing rice husk ash （RHA, 20wt% of the cementitious materials） with various average particle sizes was investigated. The total cementitious materials were 390 kg and the water-to-binder ratio （W/b） was 0.53 for all mixtures. Specimens were initially cured in water for 7 d and then immersed in the 3wt% magnesium sulphate solution for up to 111 d of exposure. The specimens were subjected to drying-wetting cycles to accelerate sulphate attack. In addition to the visual monitoring of the specimens, the concrete specimens were subsequently tested for compressive strength, dynamic modulus of elasticity, and length and mass changes. The results show that the specimens exposed to sulphate attack exhibit higher strength and dynamic modulus than those kept in water. The length change is neglig.ble and can be attributed to the normal swelling of concrete. On the other hand, concretes suffers mass loss and surface spalling and softening; the fine RHA-concrete results in a better resistance. For the accelerated sulphate attack method used in this study, mass change and visual monitoring are recommended for assessing the deterioration degree and the effectiveness of supplementary cementitious materials to resist sulphate attack.

关键词： concretes pozzolan ettringite rice husk ash (RHA) magnesium sulphate

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Driving factors behind multiple populations

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 172-181页

作者： Ruoyun Huang.baitian Tang Chengyuan Li Doug geisler Mario Mateo Ying-Yi Song Holger baumgardt Julio A.Carballo-bello Yue Wang Jundan Nie bruno Dias Joség.Fernández-Trincado School of Physics and Astronomy Sun Yat-sen UniversityZhuhai 519082China CSST Science Center for the guangdong-Hong Kong-Macao greater bay Area Zhuhai 519082China Departamento de Astronomía Universidad de ConcepcionConcepcionChile Instituto de Investigación Multidisciplinario en Ciencia y Tecnología Universidad de La SerenaLa SerenaChile Departamento de Astronomía Facultad de CienciasUniversidad de La SerenaChile Department of Astronomy University of MichiganAnn Arbor 48109USA David A.Dunlap Department of Astronomy&Astrophysics University of TorontoToronto ON M5S 3H4Canada Dunlap Institute for Astronomy&Astrophysics University of TorontoToronto ON M5S 3H4Canada School of Mathematics and Physics The University of QueenslandSt.Lucia QLD 4072Australia Instituto de Alta Investigación Universidad de TarapacáAricaChile CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Instituto de Astrofísica Departamento de Ciencias FísicasFacultad de Ciencias ExactasUniversidad Andres BelloSantiagoChile Instituto de Astronomía Universidad Católica del NorteAntofagastaChile

Star clusters were historically considered simple stellar populations,with all stars sharing the same age and initial chemical ***,the presence of chemical anomalies in globular clusters(gCs),called multiple stellar populations(MPs),has challenged star formation theories in dense *** studies show that mass,metallicity,and age are likely controlling parameters for the manifestation of *** the limit between clusters with/without MPs in physical parameter space is crucial to reveal the driving mechanism behind their *** this study,we look for MP signals in Whiting 1,which is traditionally considered a young *** the Magellan telescope,we obtained low-resolution spectra withinλλ=3850-5500?for eight giants of Whiting *** measured the C and N abundances from the CN and CH spectral indices.C and N abundances have variations comparable with their measurement errors(~0.1 dex),suggesting that MPs are absent from Whiting *** these findings with literature studies,we propose a limit in the metallicity *** compactness index parameter space,which relatively clearly separates star clusters with/without MPs(gCs/open clusters).This limit is physically *** a larger scale,the galactic environment determines cluster compactness and metallicity,leading to metal-rich,diffuse,old clusters formed ex *** proposed limit also impacts our understanding of the formation of the Sagittarius dwarf galaxy:star clusters formed after the first starburst(age≤8-10 gyr).These clusters are simple stellar populations because the enriched galactic environment is no longer suitable for MP formation.

关键词： stellar galactic galaxy

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Impact analysis of compressor rotor blades of an aircraft engine

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Frontiers of Structural and Civil Engineering 2019年第3期13卷 505-514页

作者： Y b SUDHIR SASTRY b g KIROS F HAILU R bUDARAPU Department of Aeronautical Engineering Institute of Aeronautical EngineeringDundigalHyderabad 500043India Department of Aeronautical Engineering College of EngineeringDefense UniversityBishoftu 1041Ethiopia School of Mechanical Sciences Indian Institute of Technology BhubaneswarBhubaneswar 752050India

Frequent failures due to foreign particle impacts are observed in compressor blades of the interceptor fighter MIg-23 aircraft engines in the Ethiopian air force,supplied by the Dejen Aviation *** this paper,we made an attempt to identify the causes of failure and hence recommend the suitable materials to withstand the foreign particle *** and stress analysis of one of the recently failed MIg-23 gas turbine compressor blades made up of the following Aluminum based alloys:6061-T6,7075-T6,and 2024-T4,has been performed,apart from the impact analysis of the rotor blades hit by a granite *** numerical results are correlated to the practical *** on the modal,stress and impact analysis and the material properties of the three considered alloys,alloy 7075-T6 has been recommended as the blade material.

关键词： axial flow compressor rotor and stator blades aircraft engine stress and impact analysis aluminum alloys

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Injection molding of micro-porous titanium alloy with space holder technique

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Rare Metals 2011年第6期30卷 565-571页

作者： gülsah Engin bülent Aydemir H.zkan gülsoy Marmara University Institute Graduate Studies Pure and Applied Sciences TUbITAK National Metrology Institute Marmara University Technical Education FacultyMaterials Department Tubitak-MRC Materials Technologies Research Institute

The powder space holder （PSH） and powder injection molding （PIM） methods have an industrial competitive advantage because they are capable of the net-shape production of micro-sized porous parts. In this study, micro-porous Ti6Al4V alloy （Ti64） parts were produced by the PSH-PIM process. Ti64 alloy powder and spherical polymethylrnethacrylate （PMMA） particles were used as a space holder material. After molding, binder debinding was performed by thermal method under inert gas. Debinded samples were sintered at 1250℃ for 60min in a vacuum （10-4 Pa）. Metallographic studies were conducted to determine densification and the corresponding microstructural changes. The surface of sintered samples was examined by SEM. The compressive stress and elastic modulus of the rificro-porous Ti64 samples were determined. The effects of fraction of PMMA on the properties of sintered micro-porous Ti64 alloy samples were investigated. It was shown that the fraction of PMMA could be controlled to affect the properties of the Ti alloy.

关键词： powder injection molding titanium powder porous metal sintering

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Investigation of Ti6Al4V and AA7075 alloy embedded nanofluid flow over longitudinal porous fin in the presence of internal heat generation and convective condition

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Communications in Theoretical Physics 2020年第2期72卷 23-29页

作者： g Sowmya b J gireesha S Sindhu b C Prasannakumara Department of Pg Studies and Research in Mathematics Kuvempu UniversityShankaraghatta-577451KarnatakaIndia Department of Mathematics Davangere UniversityDavangere-577002KarnatakaIndia

The thermal attributes of porous fin due to radiation and natural convection have been carried out in the presence of nanofluid *** geometry of the fin taken for the analysis is rectangular profiled longitudinal *** temperature-dependent internal heat generation condition is also considered along with Darcy’s *** two types of nanofluid containing titanium alloy(Ti6Al4V)and aluminium alloy(AA7075)immersed in water is considered for the *** modelled nonlinear ordinary differential equation is numerically solved by the Runge–Kutta–Fehlberg *** impact of geometric parameter on the heat transfer analysis of the fin due to the flow of both nanofluids is plotted and consequences are physically *** is observed that the presence of the water-based titanium alloy better enhances the fin heat transfer rate.

关键词： alloys nanofluid porous fin heat transfer analysis convective condition internal heat generation

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Secure and Light Weight Elliptic Curve Cipher Suites in SSL/TLS

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Computer Systems Science & Engineering 2022年第1期40卷 179-190页

作者： b.Arunkumar g.Kousalya Coimbatore Institute of Technology Coimbatore641014India

In the current circumstance,e-commerce through an online banking system plays a significant *** may either buy goods from E-Commerce websites or use online banking to move money to other *** a user participates in these types of behaviors,their sensitive information is sent to an untrust-worthy *** a consequence,when transmitting data from an internal browser to an external E-commerce web server using the cryptographic protocol SSL/TLS,the E-commerce web server ensures the security of the user’s *** user should be pleased with the confidentiality,authentication,and authenticity properties of the SSL/TLS on both the user’s web browser and the remote E-commerce web server.E-Commerce web servers should choose the best SSL/TLS cipher suites for negotiating the user in order to attain such optimistic scenarios,as the cipher suite used in SSL/TLS plays an important role in securing E-Commerce web *** paper primarily focuses on analyzing the SSL/TLS cipher and elliptic *** paper also recommends the best elliptic curve cipher suites for E-Commerce and online banking servers,based on their power consumption,handshake execution time,and key exchange and signature verification time.

关键词： Elliptic curve cipher suites secp256r1 curve25519 ed25519

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水解脱油卵磷脂在肉禽制品中的应用

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中国食品工业 1999年第6期 30-31页

作者： H.-g.büschelberger 德国Lucas Meyer g.bH应用部

过去,肉禽制品并不是卵磷脂的应用领域。随着新的、改进的专用卵磷脂产品的开发,如新近推出市场的水解脱油卵磷脂EMULTOP,卵磷脂已成功地踏进这个工业的大门。目前,水解脱油卵磷脂在肉禽制品中有一系列不同的应用范畴,这里介绍其中两方... 详细信息

过去,肉禽制品并不是卵磷脂的应用领域。随着新的、改进的专用卵磷脂产品的开发,如新近推出市场的水解脱油卵磷脂EMULTOP,卵磷脂已成功地踏进这个工业的大门。目前,水解脱油卵磷脂在肉禽制品中有一系列不同的应用范畴,这里介绍其中两方面——作为罐头肉、馅饼和香肠的乳化剂,以及作为禽肉注射的调味汁。

关键词：水解脱油卵磷脂卵磷脂肉制品禽肉制品

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