The article clarifies the rate of professionalism in the field of geodesy and its position toward some other comparable professions with the help of sociological tools. The mirroring picture gained ...by this analysis enables the profession to find answers to the question of its position in the society and can serve as a stimulus for an empowered improvement of its quality for the experts and the profession itself.
The article shows the ethical codes applied by a Slovenian geodesy surveyor and clarifies with sociological tools the rate of professionalism in the field of geodesy from the professional ethics ...viewpoint. The mirroring picture gained by this analysis enables the profession to find the answers to the question regarding its position in the society and can serve as a stimulus for an accelerated improvement of its quality – for the experts and the profession itself.
This paper presents a non-contact method for velocity field calculation from a series of images containing illuminated planar layer of fluid with a pollutant mixed in. Velocity field is calculated ...using a model similar to optical flow based on the advection–diffusion equation. The model which was also implemented into our software, ADMflow, is evaluated on different sets of synthetic images. Calculated velocity fields are in a good agreement with the true velocity fields, mostly deviating by less than 10% in magnitude and 1° in flow direction.
•New flow image velocimetry method based on the advection–diffusion equation.•Synthetic image sets with known ground truth were used for method evaluation.•Good agreement between velocity fields calculated by our method and true ones.•Spatiotemporal smoothing and downsampling reduce velocity calculation errors.
This paper presents a non-contact method for velocity field calculation from a series of fluid flow images with illuminated planar layer of the flow and a mixed-in pollutant for flow visualization. ...The velocity field is calculated using a model similar to optical flow that is based on the advection-diffusion equation. The model is evaluated using a set of synthetic airfoil flow visualization images generated by a combination of computational fluid dynamics and inverse advection-diffusion equation approaches. The calculated velocity fields are in a good agreement with the true velocity fields. Keywords: computer-aided visualization, image velocimetry, dense flow field calculation, optical flow, advection-diffusion equation, computational fluid dynamics V danasnjem casu obstajajo stevilne vizualizacijske metode, ki omogocajo izracun hitrostnih polj opazovanega toka tekocine, pri tem pa je njihova glavna prednost, da so brezdoticne in zato ne vplivajo na tok. Najpogosteje se uporabljajo metode, ki delujejo na osnovi krizne korelacije (npr. PIV), znane pa so tudi metode na osnovi opticnega toka. PIV metode so dokaj uveljavljene za meritve hitrostnih polj, vendar pa je njihova slabost kompleksnost in razmeroma visoka cena merilnega sistema. Metode na osnovi opticnega toka lahko po drugi strani delujejo na tokovih z manj zahtevno izvedbo vizualizacije (npr. dim, delci ...), vendar so v primerjavi s korelacijskimi se dokaj neuveljavljene in slabo racunalnisko podprte. Nas namen je bil razviti robustno racunalnisko podprto metodo na osnovi opticnega toka, ki bo omogocala analizo razlicnih tokovnih pojavov v laboratorijskem in industrijskem okolju. Metoda, implementirana v programskem okolju ADMflow, temelji na resevanju advekcijsko-difuzijske (AD) enacbe in predpostavki gostega tokovnega polja, pri cemer v AD enacbi koncentracijo polutanta v toku nadomestimo kar z lokalno sivinsko stopnjo na sliki. Z vidika natancnosti metode je kljucen del racunskega algoritma podvzorcenje slik (ang. downsampling, parameter Δxy) in uvedba penalizacijskih clenov (β, γ, θ), ki zgladijo nenadne spremembe hitrostnih gradientov, divergence in gradienta rotorja. Pred samim izracunom se slika zgladi z neutezenim filtrom (velikost okna za glajenje doloca parameter SWS), glajenje po casu pa posredno dolocimo s stevilom zaporednih slik (parameter IIE), ki se uporabijo za izracun hitrostnega polja v danem trenutku. Poleg predstavitve metode je glavni namen prispevka ovrednotiti njeno natancnost pri izracunu hitrostnih polj na razlicnih tipih tokovnih struktur. Naso vizualizacijsko metodo smo ovrednotili na sekvenci sinteticnih slik zracnega toka cez krilo (profil NACA4421) v vetrovniku, ki smo jo ustvarili v dveh korakih. Prvi korak je bila numericna simulacija zracnega toka cez krilo v okolju za racunalnisko dinamiko tekocin Fluent, pri cemer smo uporabili model SST-SAS. S tem smo dobili izhodiscna hitrostna polja (ang. ground truth), ki smo jih nato uporabili se za pripravo sinteticnih slik--simulacijo dima z uporabo AD enacbe v obratni smeri. Koncentracijo dima na izviru smo sinusno pulzirali, da smo zagotovili zadostne casovne in prostorske gradiente sivin na slikah za pravilno delovanje nase metode. Iz dobljenih sinteticnih slik smo nato v programu ADMflow izracunali hitrostna polja in jih primerjali z izhodiscnimi vrednostmi. Izvedli smo variacijo parametrov izracuna v ADMflow-u, pri cemer smo za vsak nabor parametrov (P, y, 6, Δxy, SWS, IIE) izracunali napako hitrostnih polj po iznosu (absolutni hitrosti) in smeri. Z variacijo smo ugotovili, pri katerem naboru parametrov je dosezena najmanjsa racunska napaka, na podlagi cesar smo lahko sklepali o optimalnih nastavitvah teh parametrov. Rezultati kazejo, da je metoda najbolj natancna na slojevitih, brezvrtincnih tokovih, nekoliko manj pa na vrtincnih tokovih. Napaka po iznosu hitrosti se je za razlicne tipe toka gibala med 4 in 14%, napaka po kotu pa med 0.5 in 15°. Na natancnost izracuna najizraziteje vpliva nastavitev parametra za podvzorcenje (Δxy), ki ga je potrebno prilagoditi hitrosti pomikanja tokovnih struktur med zaporednima slikama, le-ta pa naj bo 1 do 10 pikslov na sliko. Pomemben vpliv imajo tudi penalizacijski koeficienti za hitrostne gradiente (P), divergenco (y) in gradiente rotorja (6), ki znatno znizajo racunsko napako glede na primer, ko so nastavljeni na nicelne vrednosti (pri prevelikih vrednostih pa povzrocijo hiter porast napake). Optimalno stevilo zaporednih slik v enacbah (IIE) je tem nizje, cim bolj je tok nestacionaren. Glede na to, da se vizualizacija v vetrovniku z dimom obicajno uporablja le za kvalitativno analizo toka, so dobljeni rezultati (razpon napak) zelo zadovoljivi, saj predstavljena vizualizacijska metoda odpira nove moznosti za hitro, robustno in z vidika merilne opreme nezahtevno oceno hitrostnih polj toka. Glede nadaljnjega razvoja metode se kaze moznost uporabe strojnega ucenja z namenom vsaj delne avtomatizacije pri izbiri parametrov izracuna, smiseln je tudi razvoj 3D metode za opazovanje kompleksnejsih tokov. Kljucne besede: racunalnisko podprta vizualizacija, hitrostno polje, izracun gostega tokovnega polja, opticni tok, advekcijsko-difuzijska enacba, racunalniska dinamika tekocin
In the modern business world, the networked organizational connections tend to become prevailing organizational form. However, virtual organizations represent a special form of network organization. ...The backbone of virtual organization is its information system. To obtain successful and efficient operating of virtual organization, its strategic information system is of key importance. Strategic Information System (SIS) is a type of Information System that is aligned with business strategy and structure. SIS is designed to support and increase the competitive strength of a VO. We have upgraded Anthony’s paradigm, and taken into consideration the changes in the field of organization and management of modern network companies. This includes also the aspect of assuring the suitable information support to corporate management, which has to provide, at different levels and areas of operation, successful and effective management of corporate business processes in virtual environment. In the paper the aspect of defining possible fields of application of the SIS and the study of their characteristics are discussed. The theory is supported and illustrated by the LENS (Laser Engineered Net Shaping) Living Laboratory case study.
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