Intake system design procedure for engines with special requirementsPrimož Pogorevc
, Breda Kegl
, 2006, izvirni znanstveni članek
Opis: Intake manifolds provide fresh air to internal combustion engines and have a major effect on their performance. Therefore, many investigations are related to their design in order to improve the charging efficiency and to achieve theuniform distribution of fresh air among the engine cylinders. This paper deals with the design procedure of a cheap multipoint injection intake system,adapted to a racing car engine. Some special demands had to be taken into consideration. The intake manifold must contain the imposed constraint for the airflow in the shape of a single circular restrictor placed between the throttle and the engine to limit its power. The flow and the pressure lossreduction in the engine intake region were investigated with computationalfluid dynamics software. Two different geometries of the intake manifold were taken into consideration. On the basis of the numerically obtained three-dimensional results, a mathematical model of the engine with a more appropriate intake was made in the engine simulation code in order to anticipate its characteristics. The intake system was designed, practically manufactured, and tested in the laboratory. The experimental results confirmednumerical predictions, justifying the simple and relatively quick design procedure for the intake system.
Ključne besede: internal combustion engines, intake manifold, computational fluid dynamics, experiment
Objavljeno: 30.05.2012; Ogledov: 1011; Prenosov: 43
Povezava na celotno besedilo
Linguistic Relativism in the Case of Linguistic Gender and Number: A Comparison between English and SloveneTamara Kovačič
, 2016, magistrsko delo
Opis: The master’s thesis deals with linguistic relativism in the case of grammatical gender and number of two languages: English and Slovene. Firstly, the thesis presents the origins of Sapir-Whorf hypothesis, which is of significant importance for the development of linguistic relativism. The hypothesis met with a wide response amongst researchers: some agreed with the ideas, whereas others did not. Linguistic relativism suggests that the language one speaks shapes their perception of the world. In order to prove such statement, several experiments were conducted. In addition, the thesis outlines the main characteristics of grammatical gender and number in English and the Slovene language. The empirical part includes the analysis of the results of the experiment that was conducted amongst native speakers of English and native speakers of the Slovene language. Both qualitative and quantitative approaches were used for the interpretation of the results. The results show limited influence of the structure of language on the linguistic processing of the speakers, thus only partially supporting Sapir-Whorf hypothesis. In the case of gender categorization the results showed that the Slovene speakers were affected by the grammatical gender. In this respect we can say that language can influence our perception of the world. In the case of grammatical number the Slovene speakers were not more sensitive to the dual. The results thus show limited influence of the structure of language on the linguistic processing of the speakers, thus only partially supporting the Sapir-Whorf hypothesis.
Ključne besede: Sapir-Whorf hypothesis, linguistic relativism, language and thought, grammatical gender and number, experiment
Objavljeno: 15.02.2016; Ogledov: 706; Prenosov: 53
Celotno besedilo (2,79 MB)
Šahovski sistem rangiranja za primerjavo evolucijskih algoritmovNiki Veček
, 2016, doktorska disertacija
Opis: Eksperiment na področju evolucijskega računanja lahko povzamemo s štirimi
pomembnimi koraki: načrtovanje eksperimenta, zagon eksperimenta, analiza rezultatov ter interpretacija rezultatov in diskusija. Vsak korak zahteva posebno pozornost in vsebuje določene pasti, na katere moramo kot raziskovalci biti pozorni.
Disertacija podrobno opiše vse štiri korake, s posebnim poudarkom na statistični
analizi rezultatov, in predstavi novo metodo za primerjavo evolucijskih algoritmov - Chess Rating System for Evolutionary Algorithms (CRS4EAs). Predlagana metoda temelji na šahovskem rangiranju, kjer je vsak evolucijski algoritem predstavljen kot šahovski igralec, vsaka primerjava rešitev dveh algoritmov predstavlja igro med dvema igralcema (in se lahko konča z zmago enega in porazom drugega ali remijem), vsaka parna primerjava med več algoritmi pa predstavlja turnir. Osnova za predlagano metodo je šahovski sistem rangiranja Glicko-2, za katerega tekom disertacije tudi pokažemo, da je najprimernejši. Predlagano metodo skozi velik nabor eksperimentov primerjamo s statističnimi testi z ničelno hipotezo in pokažemo, da lahko s predlagano metodo učinkovito primerjamo uspešnosti evolucijskih algoritmov.
Predlagana metoda najde podobne signifikantne razlike kot bi jih našli z uporabo standardnih statističnih metod, hkrati pa omogoča absolutno vrednotenje moči in uspešnosti algoritmov, ki so vključeni v sistem. Predlagano metodo na učinkovit način uporabimo za uglaševanje parametrov evolucijskega algoritma in jo skozi nabor več eksperimentov primerjamo z drugimi metodami uglaševanja (F-Race in Revac).
Ključne besede: evolutionary algorithms, computational experiment, null hypothesis, glicko, chess rating
Objavljeno: 14.09.2016; Ogledov: 657; Prenosov: 85
Celotno besedilo (15,24 MB)
Experimental investigation of the quality and productivity of software factories based developmentAndrej Krajnc
, Marjan Heričko
, Črt Gerlec
, Uroš Goljat
, Gregor Polančič
, 2012, izvirni znanstveni članek
Opis: Software organizations are always looking for approaches that help improve the quality and productivity of developed software products. Quality software is easy to maintain and reduces the cost of software development. The Software Factories (SF) approach is one of the approaches to provide such benefits. In this paper, the quality and productivity benefits of the SF approach were examined and evaluated with an experiment involving two treatments - the traditional and the SF approach. For the purposes of this experiment, the Goal – Question – Metric (GQM) approach was used. Participants were grouped into thirty two teams. There were sixteen projects available. The results were evaluated and presented through quality and productivity criteria, which were used for the experimental study. The results showed that the Software Factories approach was significantly better than the traditional approach.
Ključne besede: software factories approach, benefits, quality, productivity, experiment
Objavljeno: 06.07.2017; Ogledov: 303; Prenosov: 100
Celotno besedilo (439,13 KB)
Gradivo ima več datotek! Več...
Numerical-experimental analysis of the foldable containers strengthSevket Celović
, Miloš Tipsarević
, Taško Maneski
, Tomaž Vuherer
, Dražan Kozak
, 2015, izvirni znanstveni članek
Opis: This paper describes the numerical and the experimental methodology for analysis of plastic packaging strength characteristics that are representative of its strength in the real life. Numerical analysis was conducted by the application of finite elements using "KOMIPS" software. The experiments were executed with the equipment "GOM" and software application "ARAMIS". The main issues we want to answer are related to correctly ordering and defining characteristics of container. This article will show how we can predict experimental results by the means of finite element analysis; we find this is a very strong learning tool that would enable designers to improve the structural strength of new products in the future. Experimental and numerical analysis results have to date shown a high degree of correlation.
Ključne besede: experiment, FEM, foldable container, strength
Objavljeno: 12.07.2017; Ogledov: 206; Prenosov: 73
Celotno besedilo (4,38 MB)
Gradivo ima več datotek! Več...
Rigid body dynamics in optimization of the machine tool vibroisolationRadomir Slavković
, Aleksandar Veg
, Nedeljko Dučić
, Nikola Slavković
, Jelena Baralić
, Ivan Milićević
, 2015, izvirni znanstveni članek
Opis: Modern design of the machine tool treats the suspending parts as a crucial element of the effective vibration isolation. Therefore the suspending items are specifically developed and subjected to extensive tests before being applied on real objects. These elements ensure accurate levelling and appropriate vibration damping. Usually selection of inadequate support element causes intensive disturbing effects in machining. The paper presents dynamics analysis of the machine tool suspended on flexible mountings. The overall analysis is conceived on a rigid body dynamics. This method enables selection of an optimal supporting configuration. Further on such an effective suspension design prevents a need for expensive monitoring of the dynamic characteristics of the mechanical system, i.e. machine tool and supports. The paper explores dynamics of a real, flexibly supported machine tool. Results are obtained with the assistance of the "SUPPORT" software. Finally the theoretical and computational statements are approved throughout extensive site measurements on the machine tool body with appropriate instrumentation.
Ključne besede: dynamics analysis, experiment, machine tool, software, transfer function
Objavljeno: 12.07.2017; Ogledov: 204; Prenosov: 100
Celotno besedilo (2,13 MB)
Gradivo ima več datotek! Več...
The Influence of Usernames on the Perception of Gender in Online CommunicationAlen Vugrinec
, 2018, magistrsko delo
Opis: The aims of this master´s thesis are to determine how certain usernames influence the perception of gender on online communication and to identify possible differences between the language of men and women used in online communication in the form of a forum.
The theoretical part discusses at first the internet in general; its origins, how communication came to be on it, the characteristics of internet language and differences between communication in real-life and online. Then we turn our attention to differences between the language of men and women, which can occur in either face-to-face (or written) communication or in online communication in general. The empirical part focuses on the experiment conducted for the purpose of this thesis. This part of the thesis contains the methods of the experiment, the details of it, the analysis of the communication happening on the forum and the analysis of the questionnaires given to the participants of the experiment. This is followed by the discussion of the findings/results and the concluding thoughts. The findings of the study confirm all the hypotheses set in the thesis, i.e.:
Hypothesis 1: the majority of the participants will not be able to guess correctly the gender of other participants in conversations with made-up usernames (Discussion 2).
Hypothesis 2: there will be differences between the language of men and women in both types of conversations regardless of the type of username used.
Hypothesis 3: participants regardless of gender will add more contributions to the forum in conversations with made-up usernames (Discussion 2) because of the anonymity.
Ključne besede: internet, online communication, language, username(s), difference, influence, experiment, men´s and women´s language, gender.
Objavljeno: 23.11.2018; Ogledov: 215; Prenosov: 37
Celotno besedilo (1,96 MB)