| | SLO | ENG | Cookies and privacy

Bigger font | Smaller font

Search the digital library catalog Help

Query: search in
search in
search in
search in
* old and bologna study programme


1 - 10 / 228
First pagePrevious page12345678910Next pageLast page
Polona Sladič, 2009, undergraduate thesis

Abstract: V svoji nalogi so opredeljene teoretične osnove nabavnega poslovanja in so primerjane s praktičnim primerom nabavnega poslovanja v podjetju Krka, d.d., Novo mesto (v nadaljevanju Krka). Na začetku je predstavljeno podjetje Krka, njen začetek in razvoj, njene dejavnosti in poslovanje v letu 2008. Nato je poudarek na samem nabavnem poslovanju v farmacevtski industriji. Na konkretni organiziranosti Službe nabave je preučena skladnost teorije s prakso, ki se izvaja v nabavi za proizvodnjo, ki ga opravlja Služba nabave. Preverjeno je kako se izvaja sam proces nabave, kako poteka načrtovanje nabave v teoriji in v podjetju Krka. V sklepnem delu naloge je predstavljen in analiziran problem operativnega načrtovanja nabave. Delo nabave je tesno povezano s prodajo in logističnim centrom. Opisano je na kakšen način je Krka prišla do bistvenega izboljšanja in zmanjšanja stroškov odpisa nepotrebne embalaže z nadgradnjo že vpeljanega sistema SAP. SAP je bil nadgrajen z APO-m in dosežena je večja optimizacija proizvodnih kapacitet. Vpeljano je tudi tako imenovano »zamrznjeno« obdobje planiranja, kar pripomore k večji točnosti planiranja in daje nabavi možnost boljšega operativnega načrtovanja.
Keywords: - nabava - planiranje nabave - MRP (Material Requirement Planning) sistem - informacijski sistem SAP (Systems, Applications and Products) - informacijski sistem APO (Advanced Planning and Optimisation
Published: 20.07.2009; Views: 3473; Downloads: 730
.pdf Full text (3,03 MB)

Heterogeneous aspirations promote cooperation in the prisoner's dilemma game
Matjaž Perc, Zhen Wang, 2010, original scientific article

Abstract: To be the fittest is central to proliferation in evolutionary games. Individuals thus adopt the strategies of better performing players in the hopeof successful reproduction. In structured populations the array of those that are eligible to act as strategy sources is bounded to the immediate neighbors of each individual. But which one of these strategy sources should potentially be copied? Previous research dealt with this question either by selecting the fittest or by selecting one player uniformly at random. Here we introduce a parameter that interpolates between these two extreme options. Setting equal to zero returns the random selection of the opponent, while positive favor the fitter players. In addition, we divide the population intotwo groups. Players from group select their opponents as dictated by the parameter , while players from group do so randomly irrespective of . We denote the fraction of players contained in groups and by and , respectively. The two parameters and allow us to analyze in detail how aspirations in the context of the prisoner's dilemma game influence the evolution of cooperation. We find that for sufficiently positive values of there exist a robust intermediate for which cooperation thrives best. The robustness of this observation is tested against different levels of uncertainty in the strategy adoption process and for different interaction networks. We also provide complete phase diagrams depicting the dependence of the impact of and for different values of , and contrast the validity of ourconclusions by means of an alternative model where individual aspiration levels are subject to evolution as well. Our study indicates that heterogeneity in aspirations may be key for the sustainability of cooperation in structured populations.
Keywords: evolutionary game theory, prisoner's dilemma, spatial games, aspirations, social systems, physics and society
Published: 19.06.2017; Views: 478; Downloads: 185
.pdf Full text (822,95 KB)
This document has many files! More...

Electrohydraulic pressure control by a self-adjusting proportional derivative controller
Darko Lovrec, Friedrich Faber, 2006, original scientific article

Abstract: The main characteristic of an electrohydraulic pump control system is the presence of an electrical signal path. It requires at least one sensor for the controlled value (in this case pressure), delivering feedback to be compared with the electrical or numerical reference in the controller. The additonal expense penalty for the sensor and the valve is offset by the advantage of flexibility in the structure and parameters of the controller in comparison to hydraulic - mechanical concepts. Thus, the transfer response can be adapted to demands, even in the operational state. Sophisticated control structures can be implemented easily in the form of computer or microcontroller programs. The layout of electrohydraulic pressure control discussed in this study includes the presented loading unit. The variable pump is designed to act together with a proportional valve having two metering edges. It is less expensive compared to the design with a synchronizing cylinder and four metering edges. However, only inferior static and dynamic performance can be expected. Hydraulic energy is supplied to the control valve directly from the output port of the pump - with the advantage of simple assembly, as there are no additional components required - but with the drawback that there is influence on the control loop`s properties at every change in the disturbance value or reference. The aim of the study presented in this paper is a more efficient and simple concept compared to other known methods for pressure control of the above mentioned pump including the dynamics of the distribution network, and also the characteristics of the hydraulic load with special focus on improvements in steady state and dynamic behaviour.
Keywords: automatic control engineering, electrohydraulic systems, pressure control, self-adjusting proportional controller
Published: 31.05.2012; Views: 1094; Downloads: 56
URL Link to full text

In-line higher order mode filters based on long highly uniform fiber tapers
Denis Đonlagić, 2006, original scientific article

Abstract: This paper presents a simple and effective design of taper-based higher order mode (HOM) filters that can effectively remove HOMs from the few-mode fibers. For this purpose, a taper manufacturing technique that allows the production of long and highly uniform tapers was developed. A filter performance was demonstrated on a standard single-mode telecommunication fiber operating at 850 nm. The HOM suppression was better than$-$39 dB, and the insertion loss ofthe fundamental mode was less than 0.15 dB.
Keywords: optical fibres, few moded fiber, fiber design, mode conversion, mode filter, noise figure, optical fiber dispersion, optical signal to noise, optical transmission systems, taper
Published: 31.05.2012; Views: 1296; Downloads: 65
URL Link to full text

Optimization of elastic systems using absolute nodal coordinate finite element formulation
Bojan Vohar, Marko Kegl, Zoran Ren, 2006, short scientific article

Abstract: An approach to a shape optimization of elastic dynamic multibody systems is presented. The proposed method combines an appropriate shape parameterization concept and recently introduced finite element type using absolute nodal coordinate formulation (ANCF). In ANCF, slopes and displacements are used as the nodal coordinates instead of infinitesimal or finite rotations. This way one avoids interpolation of rotational coordinates and problems with finite rotations. ANCF elements are able to describe nonlinear deformation accurately; therefore, this method is very useful for simulations of lightweight multibody structures, where large deformations have to be taken into account. The optimization problem is formulated as a nonlinear programming problem and a gradient-based optimization procedure is implemented. The introduced optimization design variables are related to the cross-sectional parameters of the element and to the shape of the whole structure. The shape parameterization is based on the design element techniqueand a rational B ezier body is used as a design element. A body-like design element makes possible to unify the shape optimization of both simple beams and beam-like (skeletal) structures.
Keywords: mechanics, dynamics of material systems, multibody systems, elastic mechanical systems, manipulators, dynamically loaded beams, optimum shape design, absolute nodal coordinate formulation, design element technique, finite element method
Published: 31.05.2012; Views: 1135; Downloads: 68
URL Link to full text

Stochastic resonance on excitable small-world networks via a pacemaker
Matjaž Perc, 2007, original scientific article

Abstract: We show that the correlation between the frequency of subthreshold pacemaker activity and the response of an excitable array is resonantly dependent on the intensity of additive spatiotemporal noise. Thereby, the effect of the underlying network, defining the interactions among excitable units, largely depends on the coupling strength. Only for intermediate coupling strengths is the small world property able to enhance the stochastic resonance, whereas for smaller and larger couplings the impact of the transition from diffusive to random networks is less profound. Thus, the optimal interplay between a localized source of weak rhythmic activity and the response of the whole array demands a delicate balance between the strength of excitation transfer and the effectiveness of the network structure to support it.
Keywords: stochastic resonance, small-world networks, cardiology, neurophysiology, nonlinear dynamical systems, spatiotemporal phenomena
Published: 31.05.2012; Views: 1019; Downloads: 55
URL Link to full text

Adaptive self-learning controller design for feedrate maximization of machining process
Franc Čuš, Uroš Župerl, 2007, original scientific article

Abstract: An adaptive control system is built which controlling the cutting force and maintaining constant roughness of the surface being milled by digital adaptation of cutting parameters. The paper discusses the use of combining the methods of neural networks, fuzzy logic and PSO evolutionary strategy (Particle Swarm Optimization) in modeling and adaptively controlling the process of end milling. An overall approach of hybrid modeling of cutting process (ANfis-system), used for working out the CNC milling simulator has been prepared. The basic control design is based on the control scheme (UNKS) consisting of two neural identificators of the process dynamics and primary regulator. Experiments have confirmed efficiency of the adaptive control system, which is reflected in improved surface quality and decreased tool wear.
Keywords: end milling, adaptive force control, artificial intelligence, optimisation, adaptive control systems
Published: 31.05.2012; Views: 919; Downloads: 23
URL Link to full text

Pressure control in hydraulic systems with variable or constant pumps?
Darko Lovrec, Samo Ulaga, 2007, original scientific article

Abstract: The paper deals with electrohydraulic supply systems with variable (adjustable( supply pressures. Two control concepts are used in practice: the pressure control concept using a variable pump and constant speed of the driving electric motor as the commonly used concept, and the pressure control concept with a constant pump and a speed-controlled electric motor as the alternative concept. The typical features and the applicability of both conceps, as well as their dynamic responses are studied in this work.
Keywords: automatic control engineering, hydraulic systems, pressure control, constant pumps
Published: 31.05.2012; Views: 1078; Downloads: 0

Fuzzy logic based quality monitoring in short-circuit gas metal arc welding
Marjan Golob, Arpad Köveš, 2007, original scientific article

Abstract: Conventional methods, e.g. destructive and non-destructive testing methods, are expensive and time-consuming; therefore, possibilities of online and automated quality control of a welding process during welding as such are investigated. The paper deals with the possibilities of application of fuzzy logic to the analysis of weld quality, particularly assessment of the weld surface condition by means of measurable electric signals emitted during welding. A simple fuzzy inference system was realised which could relatively efficiently assess the weld quality on the basis of time variations of the welding voltage and short-circuit time in a certain time window.
Keywords: fuzzy systems, fuzzy logic, gas metal arc welding, GMAW, quality monitoring, statistical analysis, quality control, weld quality
Published: 31.05.2012; Views: 1014; Downloads: 68
URL Link to full text

Absorptive and transformative capacities in nanotechnology innovation systems
Krsto Pandža, Robin Holt, 2007, original scientific article

Abstract: We identify managerial challenges offered by an emergent nanotechnology innovation system in which knowledge is dispersed, asymmetric and contested. We argue the proposed models of knowledge absorption and transformation enhance existing theories of knowledge and emergent technology by recognizing how and why knowledge flows among the actors in emergent technology innovationsystem. We base our argument on combined research evidence from a Delphi study concerning the future of European manufacturing, from which a selected statement has been analyzed, and from analysis of the NanoManufacturing Institute at Leeds University, UK; specifically its work in building ties between different actors associated with nanotechnology. We conclude our paper with suggestions for future research.
Keywords: technology management, nanotehnology, innovation systems, knowledge flows, absorptive capacity, transformative capacity
Published: 31.05.2012; Views: 965; Downloads: 59
URL Link to full text

Search done in 0.18 sec.
Back to top
Logos of partners University of Maribor University of Ljubljana University of Primorska University of Nova Gorica