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# Iskanje po katalogu digitalne knjižnice

 Iskalni niz: išči po NaslovAvtorOpisKljučne besedeiskanje_cistoBesediloLeto izida INALIIN NE išči po NaslovAvtorOpisKljučne besedeiskanje_cistoBesediloLeto izida INALIIN NE išči po NaslovAvtorOpisKljučne besedeiskanje_cistoBesediloLeto izida INALIIN NE išči po NaslovAvtorOpisKljučne besedeiskanje_cistoBesediloLeto izida Vrsta gradiva: Vse vrste gradiv Habilitacijsko delo (m4) Višješolska diplomska naloga (m6) Specialistično delo (m3) Diplomsko delo * (dip) Magistrsko delo * (mag) Doktorska disertacija * (dok) Raziskovalni podatki ali korpus (data) * po starem in bolonjskem študiju Jezik: Vsi jezikiSlovenski jezikAngleški jezikNemški jezikHrvaški jezikSrbski jezikAfrikanski jezikAlbanski jezikArabski jezikArmenski jezikAzerbajdžanski jezikBolgarski jezikBosanski jezikČeški jezikČrnogorski jezikDanski jezikEstonski jezikFinski jezikFrancoski jezikGrški jezikGruzinski jezikIrski jezikItalijanski jezikJaponski jezikKatalonski jezikKazaški jezikKitajski jezikLatinski jezikLatvijski jezikLitvanski jezikMadžarski jezikMakedonski jezikMalteški jezikNemški jezik (Avstrija)Nizozemski jezikNorveški jezikPoljski jezikPortugalski jezikRomunski jezikRuski jezikSlovanski jezik (ostali)Slovaški jezikSrbski jezik (cirilica)Španski jezikŠvedski jezikTurški jezikUkrajinski jezikNi določenVečjezičniNeznan jezik Išči po: DKUM    EPF - Ekonomsko-poslovna fakulteta    FE - Fakulteta za energetiko    FERI - Fakulteta za elektrotehniko, računalništvo in informatiko    FF - Filozofska fakulteta    FGPA - Fakulteta za gradbeništvo, prometno inženirstvo in arhitekturo    FKBV - Fakulteta za kmetijstvo in biosistemske vede    FKKT - Fakulteta za kemijo in kemijsko tehnologijo    FL - Fakulteta za logistiko    FNM - Fakulteta za naravoslovje in matematiko    FOV - Fakulteta za organizacijske vede    FS - Fakulteta za strojništvo    FT - Fakulteta za turizem    FVV - Fakulteta za varnostne vede    FZV - Fakulteta za zdravstvene vede    MF - Medicinska fakulteta    PEF - Pedagoška fakulteta    PF - Pravna fakulteta    UKM - Univerzitetna knjižnica Maribor    UM - Univerza v Mariboru    UZUM - Univerzitetna založba Univerze v MariboruCOBISS    Ekonomsko poslovna fakulteta    Fakulteta za kmetijstvo    Fakulteta za logistiko    Fakulteta za organizacijske vede    Fakulteta za varnostne vede    Fakulteta za zdravstvene vede    Knjižnica tehniških fakultet    Medicinska fakulteta    Miklošičeva knjižnica - FPNM    Pravna fakulteta    Univerzitetna knjižnica Maribor Opcije: Prikaži samo zadetke s celotnim besedilom Ponastavi

 1 - 10 / 1112 1.Yield strength modelling of formed material using evolutionary computational methodLeo Gusel, Rebeka Rudolf, 2009, izvirni znanstveni članekOpis: In this paper we propose an evolutionary computation approach for the modelling of yield strength in formed material. One of the most general evolutionary computation methods is genetic programming, which was used in our research. Genetic programming is an automated method for creating a working computer program from a problemćs high-level statement. Genetic programming does this by genetically breeding a population of computer programs using the principles of Darwinianćs natural selection and biologically inspired operations. During our research, material was cold formed by drawing using different process parameters and then determining yield strengths (dependent variable) of the specimens. On the basis of a training data set, various different genetic models for yield strength distribution were developed during simulated evolution. The accuracies of the best models were proved by a testing data set and comparing between the genetic and regression models. The research showed that very accurate genetic models can be developed by the proposed approach.Ključne besede: metal forming, yield strength, genetic programming, modellingObjavljeno: 31.05.2012; Ogledov: 1448; Prenosov: 25 Povezava na celotno besedilo 2.Modeling of impact toughness of cold formed material by genetic programmingLeo Gusel, Miran Brezočnik, 2006, izvirni znanstveni članekOpis: In the paper, an approach completely different from the conventional methods for determination of accurate models for the change of properties of cold formed material, is presented. This approach is genetic programming (GP) method which is based on imitation of natural evolution of living organisms. The main characteristic of GP is its non-deterministic way of computing. No assumptions about the form and size of expressions were made in advance, but they were left to the self organization and intelligence of evolutionary process. First, copper alloy rods were cold drawn under different conditions and then impact toughness of cold drawn specimens was determined by Charpy tests. The values of independent variables (effective strain, coefficient of friction) influence the value of the dependent variable, impact toughness. On the basis of training data, different prediction models for impact toughness were developed by GP. Only the best models, gained by genetic programming were presented in the paper. Accuracy of the best models was proved with the testing data set. The comparison between deviation of genetic model results and regression model results concerning the experimental results has showed that genetic models are more precise and more varied then regression models.Ključne besede: metal forming, genetic programming, evolutionary computing, impact toughness, copper alloy, modellingObjavljeno: 30.05.2012; Ogledov: 1496; Prenosov: 80 Povezava na celotno besedilo 3.Dependence of material characteristics on lubrication in bulk forming processLeo Gusel, 2009, objavljeni znanstveni prispevek na konferenciOpis: In the paper the influence of coefficient of friction (lubricant) on different properties of cold formed material has been examined. Tensile tests, hardness measurements and electrical conductivity measurements were performed.In the frame of the experimental work the process of cold forward extrusion of a cylinder made from copper alloy was investigated. The specimens were extruded at four different lubricants coefficients of friction. The results have shown that use of different lubricators with different coefficients of friction can have effects on the material properties during and after cold forming process.Ključne besede: lubrication, cold forming, copper alloy, mechanical propertiesObjavljeno: 31.05.2012; Ogledov: 1010; Prenosov: 12 Povezava na celotno besedilo 4.Optimization of extrusion process by genetic algorithms and conventional techniquesZoran Jurković, Miran Brezočnik, Branko Grizelj, Vesna Mandić, 2009, izvirni znanstveni članekOpis: The purpose of this research is the determination of the optimal cold forward extrusion parameters with the minimization of tool load as objective. This paper deals with different optimization approaches in order to determine optimal values of logarithmic strain, die angle and friction factor with the purpose to find minimal tool loading obtained by cold forward extrusion process. Two experimental plans based on factorial design of experiment and orthogonal array have been carried out. Classical optimization, according to the response model of extrusion forming force, and the Taguchi approach are presented. The obtained extrusion force model as the fitness function was used to carry out genetic algorithm optimization. Experimental verification of optimal forming parameters with their influences on the forming forces was also performed. The experimental results show an improvement in the minimization of tool loading. The results of optimal forming parameters obtained with different optimization approaches have been compared and based on that the characteristics analysis (features and limitations) of presented techniques.Ključne besede: metal forming, forward extrusion force optimization, design of experiments, Taguchi approach, genetic algortihmObjavljeno: 31.05.2012; Ogledov: 1159; Prenosov: 67 Celotno besedilo (469,47 KB)Gradivo ima več datotek! Več... 5.Determination of critical regions for cracks in extruded materialLeo Gusel, Ivan Anžel, 2010, izvirni znanstveni članekKljučne besede: cold extruded material, formability, bulk metal forming, visioplasticity analysis, copper alloyObjavljeno: 31.05.2012; Ogledov: 987; Prenosov: 24 Povezava na celotno besedilo 6.Application of numerical simulations in the deep-drawing process and the holding system with segments' insertsMihael Volk, Blaž Nardin, Bojan Dolšak, 2011, izvirni znanstveni članekOpis: The demands for complicated products have increased dramatically over the last few years taking into consideration the utilisation of sheet metal, product quality and process conditions. For reliable product development and stable production process, the use of FEM is necessary. One of the most significant parameters in the sheet metal forming process is the blank holding force. In the research work, the optimisation of the blank holding force was performed with the help of FEM analysis. For the optimisation the geometry and the structure of the blank holder was optimised. The best results were obtained with flexible, segmented blank holders, which enables wider technological window for good parts.Ključne besede: sheet metal forming, deep drawing, segmented holding system, finite elements method, optimizationObjavljeno: 01.06.2012; Ogledov: 1215; Prenosov: 58 Povezava na celotno besedilo 7.Genetic programming approach for the material flow curve determination of copper alloy - CuCrZrLeo Gusel, Miran Brezočnik, Rebeka Rudolf, Ivan Anžel, Z. Lazarević, Nebojša Romčević, 2010, izvirni znanstveni članekOpis: For the control of the forming process it is necessary to know as precisely as possible the flow curve of the formed material. The paper presents the determination of the equation for the flow curve of cooper alloy (CuCrZr) with artificial intelligence approach. The genetic programming method (GP) was used. It is an evolutionary optimization technique based on the Darwinist principles of the evolution of species and the survival of the fittest organisms. The main characteristic of GP is its non- deterministic way of computing. It is probably the most general approach out of evolutionary computation methods. The comparison between the experimental results, analytical solution and the solution obtained genetically clearly shows that the genetic programming method is a very promising approach.Ključne besede: forming, flow curve, copper alloys, genetic programmingObjavljeno: 01.06.2012; Ogledov: 947; Prenosov: 13 Povezava na celotno besedilo 8.Predicting stress distribution in cold-formed material with genetic programmingMiran Brezočnik, Leo Gusel, 2004, izvirni znanstveni članekOpis: In this paper we propose a genetic programming approach to predict radial stress distribution in cold-formed material. As an example, cylindrical specimens of copper alloy were forward extruded and analysed by the visioplasticity method. They were extruded with different coefficients of friction. The values of three independent variables (i.e., radial and axial position of measured stress node, and coefficient of friction) were collected after each extrusion. These variables influence the value of the dependent variable, i.e., radial stress. On the basis of training data set, various different prediction models for radial stress distribution were developed during simulated evolution. Accuracy of the best models was proved with the testing data set. The research showed that by proposed approach the precise prediction models can be developed; therefore, it is widely used also in other areas in metal-forming industry, where the experimental data on the process are known.Ključne besede: metal forming, stress distribution, prediction, genetic programming, modellingObjavljeno: 01.06.2012; Ogledov: 1231; Prenosov: 66 Povezava na celotno besedilo 9.Modeling of forming efficiency using genetic programmingMiran Brezočnik, Jože Balič, Zlatko Kampuš, 2001, izvirni znanstveni članekOpis: This paper proposes new approach for modeling of various processes in metal-forming industry. As an example, we demonstrate the use of genetic programming (GP) for modeling of forming efficiency. The forming efficiency is a basis for determination of yield stress which is the fundamental characteristic of metallic materials. Several different genetically evolved models for forming efficiency on the basis of experimental data for learning were discovered. The obtained models (equations) differ in size, shape, complexity and precision of solutions. In one run out of many runs of our GP system the well-known equation of Siebel was obtained. This fact leads us to opinion that GP is a very powerful evolutionary optimization method appropriate not only for modeling of forming efficiency but also for modeling of many other processes in metal-forming industry.Ključne besede: metal forming, yield stress, forming efficiency, mathematical modeling, adaptation, genetic methods, genetic algorithm, genetic programming, artificial intelligence, process optimisationObjavljeno: 01.06.2012; Ogledov: 1216; Prenosov: 87 Povezava na celotno besedilo 10.Reactive sintering of $MnZn$ ferritesTomaž Kosmač, Mihael Drofenik, 2001, izvirni znanstveni članekOpis: Reaction-formed $MnZn$ ferrite was prepared and the decrease in shrinkage after sintering due to the volume expansion accompanying iron oxidation was studied. Green compacts consisting of the milled raw oxides $Fe_2O_3$, $Mn_3O_4$, $ZnO$ and metallic iron powder were sintered at 1350 °C in air. During the first hold at 800 °C, $Fe$ was oxidized to $\alpha-Fe_2O_3$ and $Zn$ ferrite was formed. Above 1300 °C the reaction bonding was completed and $MnZn$ ferrite, exhibiting a relatively low shrinkage, was formed. The chemical reactions involved during reaction bonding were associated with a volume expansion and porosity formation, compensating for the shrinkage on sintering. Intensive milling decreases the porosity after sintering but induces the oxidation of iron, and partially removes the shrinkage compensation caused by the presence of metallic iron.Ključne besede: reaction-forming, $MnZn$ ferrite, inorganic technology, ferrite ceramics, reaction bonded ceramics, sintering, iron oxides, ironObjavljeno: 25.08.2017; Ogledov: 370; Prenosov: 51 Celotno besedilo (441,54 KB)Gradivo ima več datotek! Več...
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