Spatial ability has been confirmed to be of particular importance for successful engineering graphics education and to be a component of human intelligence that can be improved through instruction ...and training. Consequently, the creation and communication by means of graphics demand careful development of spatial skills provided by the balanced curricula based on the research results in multi disciplinary area. The approach to engineering graphics education had been transformed to meet spatial skills improvement even before significant and fast changes arose from the development of computer technology enabling the engineer powerful tools and techniques. The correlation and interference between new technologies widely introduced in engineering graphics education and spatial ability/skills, have initiated new studies to establish the basis of holistic engineering graphics education. This paper presents the overview of some efforts and possible answers resulting from intensive research into spatial ability and skills and their implementation in the conception of graphics education in engineering environment.
This article presents a review of glyph-based techniques for engineering visualization as well as practical application for the multivariate visualization process. Two glyph techniques, Chernoff ...faces and star glyphs, uncommonly used in engineering practice, are described, applied to the selected data set, run through the chosen optimization methods and user evaluated. As an example of how these techniques function, a set of data for the optimization of a heat exchanger with a microchannel coil is adopted for visualization. The results acquired by the chosen visualization techniques are related to the results of optimization carried out by the response surface method and compared with the results of user evaluation. Based on the data set from engineering research and practice, the advantages and disadvantages of these techniques for engineering visualization are identified and discussed.
The development of three-dimensional Computer
Aided Design (3D CAD) technology has
additionally spurred research into spatial ability to
find the ways for its enhancement through teaching
and ...instruction and to understand the mechanism
of its assessment. The techniques involved in
multimedia engineering environment of today as
well as their inclusion into engineering curricula
and courses have to be strongly supported by wider
knowledge of spatial ability.
This paper i
s a review of research results applied to
engineering graphics education by respecting
spatial ability as a recognized predictor of success
in engineering. The development of engineering
graphics teaching based on research suggestions
about spatial ability represents an increasingly
complex approach that puts additional stress on
engineering graphics educators. Thus classical
tests for the assessment of spatial ability are
described, the applied strategies for their solving
are presented, the selected obtained results are
compared, and a distinction is drawn between the
strategies employed for more complex spatial tasks
that engineering is dealing with.
Na promjene u procesu konstruiranja znatno je utjecala povećana upo-
raba modeliranja tijela, što je rezultiralo snažnijim odnosom između kon-
struiranja i inženjerske grafike. Mogu se pratiti ...nastojanja, od stidljivih
promjena uključivanjem 2D i 3D modela u uvodni kolegij inženjerske
grafike, do pristupa upotpunjavanja parametarskim modeliranjem na os-
novi značajke i ograničenja, što dovodi do razvitka inženjerskog nastavnog
programa s 3D modelom u središtu.
Ovaj rad predstavlja neke karakteristične pristupe izabrane iz brojnih
doprinosa koji obrađuju uvođenje novih tema i tehnologija u obrazovanje
inženjerske grafike, kao i primjer inženjerskog nastavnog programa s 3D
modelom u središtu. Izdvojen je pregled tema koje su najčešći prijedlog
za uvodni kolegij inženjerske grafike, bez obzira na različite pristupe koji
trebaju ostvariti vezu između 3D modeliranja, inženjerskog konstruiranja
i aplikacija.
Također je predstavljen kratki opis kolegija inženjerske grafike i
obuhvaćenih tema na Tehničkom fakultetu u Rijeci, kao rezultat dorada
koje daju naglasak na 3D modeliranje i njegovu ulogu u procesu istodobnog
inženjerskog konstruiranja.
In this paper a comparative study of several algorithms for the optimization of heat exchanger with microchannel coil has been done. Multivariate optimizations have included three geometrical ...parameters of heat exchanger which, as predicted, significantly influence hydrodynamic behavior of the system. Data set used for the optimizations have been numerically acquired and experimentally validated. The air/water side numerical model of heat exchanger composed of flat tubes with rectangular shapes has been used. Objective function that combines the heat transfer rate and the pressure drops of air and water has been developed and employed for the optimization procedures. The optimization has been performed by means of two evolutionary algorithms (Genetic Algorithm and Simulated Annealing) and Pattern Search Algorithm. The comparison of obtained results has been accomplished along with the results analysis and final conclusions.
In this work the gear tooth root stress was calculated by means of numerical method 2D FEM (two-dimensional Finite Element Method) and according to two analytical methods, that included the stress ...calculation method B of standard ISO 6336-3 and its modified form - method MAX. In order to evaluate the rim thickness factor introduced by the method B of standard ISO that takes into account the influence of rim thickness on nominal tooth root stress, the stress at a spur tooth root of cylindrical external gearing was determined going from solid towards thin rimmed gear, and considering the gear with various number of teeth.
MODELIRANJE POMOĆU ZNAČAJKE Gregpv, Goran; Marunić, Gordana; Glažar, Vladimir
Engineering Review,
07/2008, Letnik:
28, Številka:
1
Journal Article
Recenzirano
Odprti dostop
U radu su predstavljeni osnovni načini razvoja modela značajke proizvoda. Istraživanja i unapređenja modeliranja pomoću značajke, kao modeliranja proizvoda koji omogućava pohranu geometrijskih i ...funkcijskih informacija u jednom modelu, nisu u potpunosti ostvarena. Uz pregled većih nedostataka koji prate sadašnje sustave za modeliranje pomoću značajke, a to su održanje značenja značajke, postojanje samo jednog modela proizvoda, ograničene mogućnosti kolaborativnog modeliranja i ograničena domena oblika, prikazana su i istraživanja usmjerena rješavanju tih nedostataka.
The paper presents basic ways for the development of product feature model. The investigation and improvement of feature modelling, as product modelling that enables geometrical and functional ...information to be stored in a single model, has not been accomplished completely. Along with survey of major shortcomings that accompany current feature modelling systems, consisting of maintenance of feature semantics, the existence of only one product feature model, the limited facilities of collaborative modelling, and the limited shape domain the investigations aimed at solving these shortcomings are also presented.
U radu je naprezanje u korijenu zuba zupčanika izračunato pomoću numeričke metode 2D MKE (dvodimenzijska metoda konačnih elemenata) i u skladu s dvjema analitičkim metodama koje su obuhvatile ...proračun naprezanja prema metodi B, opisanoj u normi ISO 6336-3 i njezin modificirani oblik, metodu MAX. Da bi se vrjednovao faktor debljine vijenca kojim se prema metodi B norme ISO uzima u obzir utjecaj debljine vijenca na nazivno naprezanje u korijenu zuba, naprezanje u korijenu zuba cilindričnog zupčanika s vanjskim ozubljenjem ravnim zubima određeno je krećući od punog zupčanika prema zupčaniku s tankim vijencem, uzimajući pri tome u obzir zupčanik s različitim brojem zubi.
The plasma levels of matrix metalloproteinase-9 (MMP-9) were determined during 41 collections of peripheral blood stem cells (PBSC) by standard volume (two blood volumes) leukaphereses (SVL) in 29 ...donors (7 allogeneic and 22 autologous) mobilized with the granulocyte-colony stimulating factor (G-CSF). The association between MMP-9 levels and cell counts in donor’s blood was explored. During the processing of the first blood volume (BV), MMP-9 levels declined on average by 31% and persisted at the same level during the processing of the second BV. During the collection, a slight decline of white blood cells (WBC), polymorphonuclear neutrophils (PMN) and platelets (PLT) in donor’s blood was accompanied by a significant drop of CD34+ cells by 37% after 1 BV and by 44% after 2 BV had been processed (
p
=
0.001). The drop of MMP-9 plasma levels showed a loose correlation with the decrease of WBC (
r
=
0.68,
p
=
0.002) and PMN counts (
r
=
0.67,
p
=
0.001). We conclude that the levels of MMP-9 that have been elevated by the mobilization of donors with G-CSF, decrease during the collection of PBSC by 4
h SVL. The observed decrease was indirectly related to the drop of WBC and PMN counts, suggesting that certain other factors have an influence on MMP-9 kinetics during PBSC collection.
