Optimizacija denarnih tokov pri gradnji cest z genetskim algoritmom

In this paper a method for optimization of cash flows in the construction and management of road network is presented. On the basis of the last official National highway Construction Program (NPIA) update, in 2004, the methodology and a computer program that simulate and optimize the cash flow with genetic algorithm were designed. The computer program contains the model that simulate the cash flows, and the optimization algorithm, which runs through the delayed construction of individual road sections. For criteria the maximized net present value (NPV) and minimized the time deviation from the original plan were used. Multi-criteria optimization is discussed by using different weights. The optimization results were the optimal values of selected financial and time parameters, which are shown on the Pareto curve.V članku je prikazan primer optimizacije denarnih tokov pri gradnji in upravljanju cestnega omrežja. Na osnovi podatkovne baze iz zadnje uradne posodobitve Nacionalnega programa izgradnje avtocest (NPIA) v letu 2004 sta bila izdelana metod­ologija in računalniški program, ki omogočata simulacijo in optimizacijo denarnih tokov z genetskim algoritmom. V okviru računalniškega programa sta bila izdelana model, ki simulira denarne tokove, in optimizacijski algoritem, ki je na model nave­zan preko zamika gradnje posameznih cestnih odsekov. Za kriterija sta bila uporabljena maksimizirana neto sedanjo vrednost (NSV) in minimizirano časovno odstopanje od prvotnega načrta. Optimizacijski algoritem vključuje večkriterijsko optimizacijo z uporabo različnih uteži. Rezultat optimizacije so vrednosti izbranih finančnih in časovnih parametrov. Optimalne rešitve z uporabo različnih uteži oz. razmerij med NSV in časovnim odstopanjem od prvotnega načrta so prikazane s Paretovo krivuljo

Dejavniki, ki vplivajo na meritve hitrosti branja barvnih spletnih strani

Most of web-based systems use a fashion-driven graphical user interface design which does not necessarily provide the readers with high reading performance of colour variations of text and background. Many studies addressed this problem but none of them succeeded in offering complete and conclusive results in form of reading performance table which could be used in practice. The aim of this paper is to find reasons for these incomplete results. In our research, we firstly analyzed different experiment designs described in the literature and proposals for further research. Consequently, we tried to find an improved design and carried out an experiment involving 270 students who tested 30 web-safe colour combinations. However, our experiment also did not reveal statistically significant differences in reading speed. Therefore the multidimensional scaling (MDS) method was performed to show that the speed of reading cannot be described as a one-dimensional problem.Veliko spletnih sistemov uporablja uporabniški vmesnik, ki je oblikovan na osnovi modnih smernic, ki pa ne upoštevajo vedno tudi berljivost besedila, ki je odvisna od barve le-tega in barve podlage. S tem problemom se je ukvarjalo veliko študij, ki pa niso uspele ponuditi končnih rezultatov v obliki tabele berljivosti, ki bi bila uporabna v praksi. Namen tega članka je najti vzroke za to. Najprej smo analizirali različne oblike preskusov, ki so opisane v literaturi in tudi smernice nadaljnjega raziskovanja. Na osnovi analize smo oblikovali izboljšan preskus in ga izvedli z 270 študenti. Testirali so 30 spletno varnih barvnih kombinacij. Vendar tudi naš preskus ni pripeljal do tabele berljivosti s statistično značilnimi razlikami med barvnimi kombinacijami. Zato smo s statistično metodo MDS analizirali vzroke za to. Ugotovili smo, da tabele berljivosti zaradi praktičnih omejitev pri izvedbi preskusa ni možno določiti oziroma, da berljivosti ni možno obravnavati kot enodimenzionalni problem

Teledelo v Sloveniji

Čeprav je raziskav teledela veliko, pa je večina omejenih le na ZDA in države Evropske skupnosti. V državah centralne in vzhodne Evrope pa do zdaj še ni bilo tovrstnih raziskav. V prispevku so prikazani rezultati raziskave teledela v Sloveniji, ki je bila izvedena v letu 1997. Podana je tudi primerjava stanja v Sloveniji s stanjem v nekaterih drugih evropskih državah.Although a lot of research on telework has been done, most of it was carried out in USA and EC countries. Until today there have been no studies on telework in Central and Eastern Europe. This paper shows the results of research on telework in Slovenia carried out in the year 1997. Slovenia is a country in Central Europe, located between Italy, Austria, Hungary and Croatia. In the paper also some comparisons between Slovenia and other European countries are shown