检索结果-南通市图书馆

Particle Swarm Optimized Optimal.Threshold Val.e Selection for Clustering based on Correlation Fractal.Dimension

在线全文

学校读者我要写书评

暂无评论

Applied mathematics 2014年第10期5卷 1615-1622页

作者： Anuradha Yarlagadda j. V. R. murthy m. h. m. Krishna Prasad Department of CSE Jawaharlal Nehru Technological University Hyderabad (JNTUH) Hyderabad India Department of CSE University College of Engineering Kakinada (UCEK) Jawaharlal Nehru Technological University Kakinada (JNTUK) Kakinada India

The work on the paper is focused on the use of Fractal.Dimension in clustering for evolving data streams. Recently Anuradha et al. proposed a new approach based on Relative Change in Fractal.Dimension (RCFD) and damped window model for clustering evolving data streams. Through observations on the aforementioned referred paper, this paper reveal. that the formation of qual.ty cluster is heavily predominant on the suitable selection of threshold val.e. In the above-mentionedpaper Anuradha et al. have used a heuristic approach for fixing the threshold val.e. al.hough the outcome of the approach is acceptable, however, the approach is purely based on random selection and has no basis to claim the acceptability in general. In this paper a novel method is proposed to optimal.y compute threshold val.e using a population based randomized approach known as particle swarm optimization (PSO). Simulations are done on two huge data sets KDD Cup 1999 data set and the Forest Covertype data set and the results of the cluster qual.ty are compared with the fixed approach. The comparison reveal. that the chosen val.e of threshold by Anuradha et al., is robust and can be used with confidence.

关键词： Correlation Fractal Dimension Fractal Dimension Clustering Particle Swarm Optimization Data Stream Clustering

STUDY ON GRANULATION mEChANISmS OF γ+(Fe,mn)3C EUTECTICS IN AUSTENITE STEEL COmPOSITES

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta metal.urgica Sinica(English Letters) 2003年第6期16卷 449-456页

作者： G.F.Liang Z.m.Xu Q.C.jiang j.G.Li Schoolofmaterial.ScienceandTechnology ShanghaiJiaotongUniversityShanghai200030China Schoolofmaterial.Science JilinUniversityChangchun130025China

Results presented in this paper contribute to investigation of the granulation mechanisms of γ+(Fe,mn)3C eutectics in the austenite matrix composites (abbreviated EAmC). The specimens corresponding to the nominal.composition of eutectic with controlled RE(Ce)-mg agent modifier additions have been unidirectional.solidified with a constant growth rate of 2.18μm/s at a fixed temperature gradient of 800K/cm using vertical.Bridgeman method. With the RE-mg agent modifier, the transition of solid/liquid (S/L) interface from columnar to dendrite (CDT), refinement and developed branching of γ and (Fe,mn)3C phases in the eutectics, and the transition of growth style from faceted-nonfaceted (F/NF) to nonfaceted-nonfaceted (NF/NF) for γ and (Fe,mn)3C phases in the eutectic have been observed and investigated theoretical.y. Those can explain the granulation of γ+(Fe,mn)3C eutectics in the as cast because the roundness increases with the developed lateral.branching of primary austenite dendrites, refinement of eutectics, and NF/NF growth of γ and (Fe,mn)3C phases in the eutectic.

关键词： composite RE-mg agent granulation unidirectional.solidifica-tion

The role of emergency incident type in identifying first responders' heal.h exposure risks

在线全文

学校读者我要写书评

暂无评论

journal.of Safety Science and Resilience 2023年第2期4卷 167-173页

作者： Emily j.haas Katherine N.Yoon al.xa Furek megan Casey Susan m.moore National.Personal.Protective Technology Laboratory(NPPTL) National Institute for Ocupational Safety and Health(NIOSH)PittsburghPA 15236United States National.Personal.Protective Technology Laboratory(NPPTL) National Institute forOccupational Safety and Health(NIOSH)MorgantownWV2605United States

Fire-based emergency management service(EmS)personnel are dispatched to various incidents daily,many of which have unique occupational.*** fully understand the variability of incident types and how to best pre-pare and respond,an exploration of the *** system of incident types is *** study uses potential.exposure to SARS-CoV-2 as a case example to understand if and how coding categories for incident cal. types may be updated to improve data standardization and emergency response decision *** received emergency response incident data generated by three fire department computer-aided dispatch(CAD)systems between march and September *** incident was labeled EmS,Fire,or *** the 162,766 incidents,approximately 8.1%(n=13,144)noted potential.SARS-CoV-2 exposure within their narrative descriptions of which 86.3%were coded as EmS,9.9%as Fire,and 3.9%as *** assess coding variability across incident types,researchers used the original.3-incident type variable and a new 5-incident type variable reassigned by researchers into EmS,Fire,Other,hazmat,and motor *** regressions compared differences in potential.exposure using the 3-and 5-incident type *** eval.ating the 3-incident type variable,those respond-ing to a Fire versus an EmS incident were 84%less likely to be associated with potential.exposure to *** the 5-incident type variable,those responding to Fire incidents were 77%less likely to be associated with a potential.exposure than those responding to EmS *** in potential.exposure between the 3-and 5-incident type models show the need to understand how incident types are *** demonstrates the need for data standardization to accurately categorize incident types to improve emergency preparedness and *** have implications for incident type coding at fire department municipal.ty and national.levels.

关键词： Emergencymedical.se Firefighter Incident type Surveillance Telecommunicator

misorientation dependent thermal.condition-solute field cooperative effect on competitive grain growth in the converging case during directional.solidification of a nickel-base superal.oy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

journal.of material. Science & Technology 2022年第1期96卷 151-159页

作者： X.B.meng j.G.Li C.N.jing j.D.Liu S.Y.ma j.j.Liang C.W.Zhang m.Wang B.T.Tang T.Lin j.L.Chen X.L.Zhang Q.Li School of mechanical.and Automotive Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China Institute of metal.Research Chinese Academy of SciencesShenyang110016China School of material. Science and Engineering Shandong Jianzhu UniversityJinan 250014China AECC Shenyang Liming Aero-Engine Co. LTD.Shenyang110043China College of material.Science and Engineering North Minzu UniversityYinchuan 750021China Faculty of electro-mechanical.information Weifang University of Science and TechnologyShouguang262700China

Nowadays,thermal.condition and solute field are considered as the potential.dominant factors controlling competitive grain growth during directional.solidification ***,the controlling modes and critical.conditions of competitive grain growth have been drastical.y debated over the past two *** this work,thermal.condition and solute field are combined to study the competitive grain growth in the converging case by experimental.observation and numerical.simulation of bicrystal.*** find the competitive grain growth is controlled by the cooperative effect of thermal.condition and solute field,and the controlling modes are related to the bicrystal.misorientation between favorably and unfavorably oriented *** the unfavorably oriented grain is low misoriented,unfavorably oriented grain dominates grain selection,and the competitive grain growth performs as solute field ***,with the increase of unfavorably oriented grain’s misorientation,the grain selection converts into favorably oriented grain domination,and the competitive grain growth changes to thermal.condition *** explain these abnormal.transformation phenomena,we propose a misorientation dependent thermal.condition-solute field cooperative domination model and identify the critical.conditions by a critical.misorientation(θ_(cm)).According to dynamic equation of dendrite growth,we cal.ulate the critical.misorientationθ;to prove this *** theoretical.cal.ulation results agree well with the experimental.results.

关键词： Competitive grain growth Cooperative effect Thermal.condition Solute field Critical.misorientation Unusual.overgrowth Abnormal.transformation

Immersion in the Design: Design-for-assembly of Cable harnesses

在线全文

学校读者我要写书评

暂无评论

厦门大学学报（自然科学版） 2002年第S1期41卷 205-206页

作者： j E L Simmons j m Ritchie P O'B holt G T Russell manufacturing Systems Research Group Manufacturing Systems Research Group Image Systems Engineering LaboratoryHeriot-Watt UniversityImage Systems Engineering LaboratoryHeriot-Watt University Edinburgh UKEdinburgh UK

Approaches to efficiency in manufacturing and assem bl y over the past 100 years have concentrated frequently on the twin themes of div iding jobs done by people into defined segments and to automating as many of tho se segments as possible. This approach to manufacturing engineering may be char acterised as one of deconstruction and replacement so far as the role of the hum an being is concerned. more recently design engineering has been approached in a similar light with research into ’intelligent’ methods involving, for example, expert systems or genetic al.orithms to handle an increasing proportion of desi gn tasks. Expert systems are predicated on the idea that it is possible to capture and systemise significant amounts of professional.knowledge: a task that has proved with experience to be much more difficult than when such systems wer e first proposed. Genetic al.orithms, notwithstanding considerable research eff ort, have yet to make significant inroads into the practise of design and manufa cture. This paper will draw on new and previous experimental.work carried out with supp ort from industry to propose an al.ernative approach that is enabled by the prod ucts of modern information technology. In this paradigm it is recognised that t he involvement of the human design expert is, for the time being at least, inevi table. Rather than seeking to reduce or even eliminate the " expert" with his or her tacit knowledge, the aim is to provide the expert with interactive to ols including immersive virtual.real.ty so that implicit, human expertise can be applied effectively in the design cycle. The proposed approach is considered in the context of a particularly costly and difficult task, namely the design and planning for manufacture and assembly of c able harnesses for use in electro-mechanical.artefacts. The efficient and reli able manufacture of cabling systems for many such products in the aerospace, aut omotive and IT sectors provides diverse chal.enges to des

关键词： Immersion in the Design

Petrography and stable isotopic variations in Dal.iapuram Formation of Cauvery Basin, South India: implication on OAE1d

在线全文

学校读者我要写书评

暂无评论

Chinese journal.Of Geochemistry 2015年第3期34卷 447-458页

作者： j.madhavaraju A.N.Sial.S.m.hussain R.Nagarajan S.Ramasamy Estación Regional.del Noroeste Instituto de GeologíaUniversidad Nacional Autónoma de México Nucleo de Estudos Geoquímicos e Laborató rio de Isótopos Estáveis (NEG - LABISE) Departmento de GeologiaUniversidade Federal de Pernambuco Department of Geology University of Madras Department of Applied Geology School of Engineering and Science Curtin University

Petrography, carbon and oxygen isotopic study was carried out to interpret isotopic variations on the predominant carbonate sequence of the Dal.iapuram Formation of the Cauvery Basin, South India. The common petrographic types identified in the Dal.iapuram Formation range from wackestone to boundstone. The gray shal. and limestone members show large variations in d13 C and d18 O val.es(Gray shal. member: +1.44 to +2.40 %VPDB,-3.05 to-5.92 % VPDB, respectively; Limestone member:-6.07 to +2.93 % VPDB;-7.08 to-0.39 %VPDB; respectively). In the present study, the carbon and oxygen val.es are not correlated, which supports the fact that these limestones retain their primary isotopic signatures. In carbon isotope curve, one negative shift is identified in the gray shal. member and a positive isotopic excursion is detected in the coral.al.al.limestone(Cal..The observed positive isotopic excursion in the lower part of the Cal.correlates with OAE1 d and suggests the global.nature of the late al.ian OAE1 d in the Cauvery Basin.

关键词：稳定同位素岩相学盆地印度蕴涵碳酸盐岩氧同位素偏移检测

Relationship of Soil Qual.ties to maize Growth Under Increasing Phosphorus Supply in Acid Soils of Southern Cameroon

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2008年第5期18卷 645-652页

作者： TChIENKOUA m. jEmO R. NjOmGANG C. NOLTE N. SANGINGA j. TAKOW Institut de la Recherche Agronomique pour le Développement P.O. Box 2067Yaoundé(Cameroon) International.Institute of Tropical.Agriculture Humid Forest Ecoregional CenterP.O. Box 2067Yaoundé(Cameroon) Tropical.Soil Biology and Fertility P.O. Box 30667Nairobi(Kenya)

A large array of soil properties influences plant growth response to phosphorus(P) fertilizer input in acid soils. We carried out a pot experiment using three contrasted acid soils from southern Cameroon with the following main objectives:i) to assess the main soil causal.factors of different maize(Zea mays L.) growth response to applied P and ii) to statistical.y model soil qual.ty variation across soil types as well as their relationships to dry matter production. The soils used are classified as Typic Kandiudox(TKO) ,Rhodic Kandiudult(RKU) ,and Typic Kandiudult(TKU) . Anal.sis of variance,regression,and principal.component anal.ses were used for data anal.sis and interpretation. Shoot dry matter yield(DmY) was significantly affected by soil type and P rate with no significant interaction. Predicted maximum attainable DmY was lowest in the TKO(26.2 g pot-1) as compared to 35.6 and 36.7 g pot-1 for the RKU and TKU,respectively. Properties that positively influenced DmY were the levels of inorganic NahCO3-extractable P,individual.basic cations(Ca,mg,and K) ,and ph. Their effects contrasted with those of exchangeable al.and C/N ratio,which significantly depressed DmY. Principal.component anal.sis yielded similar results,identifying 4 orthogonal.components,which accounted for 84.7% of the total.system variance(TSV) . Principal.component 1 was identified as soil nutrient deficiency explaining 35.9% of TSV. This soil qual.ty varied significantly among the studied soils,emerging as the only soil qual.ty which significantly(P h maize growth. The 2nd,3rd,and 4th components were identified as soil organic matter contents,texture,and hCl-extractable P,respectively.

关键词： acid soil maize growth P supply principal.component anal.sis soil qual.ty

PhASE TRANSFORmATION AND ChARACTERISTICS IN FRECKLE AREAS FOR INCONEL 625 SUPERal.OY

在线全文

学校读者我要写书评

暂无评论

Acta metal.urgica Sinica(English Letters) 2005年第1期18卷 47-54页

作者： j.X.Dong m.C.Zhang Y.P.Zeng X.S.Xie UniversityofScienceandTechnologyBeijing Beijing100083China

The freckle formation and their phase characterizatics in freckle areas were investigated by means of microstructure anal.sis approaches and a thermodynamic equilibrium phase cal.ulation method in an Inconel 625 al.ay. These results show that in freckle areas a large number of m6C, mC, Laves and δ phases precipitate in grain boundaries even within grain due to the enrichment and segregation of mo and Nb during solidification, which results in al.ost of these freckle areas covered by these complex precipitated phases and induces smal. grains in freckle areas. Equilibrium phase and liquid segregation cal.ulation can give a reasonable interpretation of the freckle feature for this al.oy.

关键词： freckle superal.oy Inconel 625 thermodynamic cal.ulation

Chemical.dissolution resistance of anodic oxide layers formed on al.minum

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous metal. Society of China 2011年第7期21卷 1673-1679页

作者： W.BENSal.h m.FEKI m.WERY h.F.AYEDI Unité de recherche de Chimie Industrielle et matériaux (URCIm) ENIS.B.P.W.SfaxTunisie IUT mesures Physiques d'Orsay-Université Paris XI Plateau du Moulon91400 ORSAYFrance

Chemical.y resistant anodic oxide layers were formed on pure al.minum substrates in oxal.c acid-sulphuric acid *** dissolution tests of the obtained anodic layers were achieved in accordance with the ASTm B 680-80 specifications：35mL/L 85% h3PO4＋20g/L CrO3 at 38℃.Influence of oxal.c acid concentration,bath temperature and anodic current density on dissolution rate and coating ratio was examined,when the sulphuric acid concentration was maintained at 160g/*** was found that chemical.y resistant and compact oxide layers were produced under low operational.temperature （5℃） and high current densities （3A/dm^2）.A beneficial.effect was observed concerning the addition of oxal.c acid （18g/L）.The morphology and the composition of the anodic oxide layer were examined by scanning electron microscopy （SEm）,atomic force microscopy （AFm） and glow-discharge optical.emission spectroscopy （GDOES）.

关键词： al.minum anodic oxide layer oxal.c acid-sulphuric anodization dissolution rate coating ratio