Dragan D. Kukolj

Dr. Dragan D. Kukolj

Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia
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Research Focus & Metrics

Academic Career Length

30Years (1997-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 January 2004 in IEEE Transactions on Systems, Man, and Cybernetics, Part B (Cybernetics)
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Journal Article
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DKDragan D. Kukolj
Dragan D. Kukolj
ELE. Levi
E. Levi
The paper describes a neuro-fuzzy identification approach, which uses numerical data as a starting point. The proposed method generates a Takagi-Sugeno fuzzy model, characterized with transparency, high accuracy and a small number of rules. The process of self-organizing of the identification model consists of three phases: clustering of the input-output space using a self-organized neural network; determination of the parameters of the consequent part of a rule from over-determined batch least-squares formulation of the problem, using singular value decomposition algorithm; and on-line adaptation of these parameters using recursive least-squares method. The verification of the proposed identification approach is provided using four different problems: two benchmark identification problems, speed estimation for a DC motor drive, and estimation of the temperature in a tunnel furnace for clay baking.

1 December 2002 in Applied Soft Computing
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Journal Article
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DKDragan D. Kukolj
Dragan D. Kukolj

6 March 2009 in IEEE Transactions on Neural Networks
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Journal Article
Closed access
Nikola GradojevicNikola Gradojevic
Nikola Gradojevic
RGRamazan Gencay
Ramazan Gencay
DKDragan D. Kukolj
Dragan D. Kukolj
This paper investigates a nonparametric modular neural network (MNN) model to price the S&P-500 European call options. The modules are based on time to maturity and moneyness of the options. The option price function of interest is homogeneous of degree one with respect to the underlying index price and the strike price. When compared to an array of parametric and nonparametric models, the MNN method consistently exerts superior out-of-sample pricing performance. We conclude that modularity improves the generalization properties of standard feedforward neural network option pricing models (with and without the homogeneity hint).

1 January 2016 in Journal of Electrical Engineering
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Journal Article
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DSDragana Sandić-Stanković
Dragana Sandić-Stanković
DKDragan D. Kukolj
Dragan D. Kukolj
PCPatrick Le Callet
Patrick Le Callet
The Depth-Image-Based-Rendering (DIBR) algorithms used for 3D video applications introduce geometric distortions affecting the edge coherency in the synthesized images. In order to better deal with specific geometric distortions in the DIBR synthesized images, we propose full-reference metric based on multi-scale pyramid decompositions using morphological filters. The non-linear morphological filters used in multi-scale image decompositions maintain important geometric information such as edges across different resolution levels. We show that PSNR has particularly good agreement with human judgment when it is calculated between detailed images at higher scales of morphological pyramids. Consequently, we propose reduced morphological pyramid peak signal-to-noise ratio metric (MP-PSNR), taking into account only mean squared errors between pyramids’ images at higher scales. Proposed computationally efficient metric achieves significantly higher correlation with human judgment compared to the state-of-the-art image quality assessment metrics and compared to the tested metric dedicated to synthesis-related artifacts.

1 May 2015
Verified
Conference Paper
Closed access
DSDragana Sandic-Stankovic
Dragana Sandic-Stankovic
DKDragan D. Kukolj
Dragan D. Kukolj
PCPatrick Le Callet
Patrick Le Callet
Most of the Depth Image Based Rendering (DIBR) techniques produce synthesized images which contain nonuniform geometric distortions affecting edges coherency. This type of distortions are challenging for common image quality metrics. Morphological filters maintain important geometric information such as edges across different resolution levels. In this paper, morphological wavelet peak signal-to-noise ratio measure, MW-PSNR, based on morphological wavelet decomposition is proposed to tackle the evaluation of DIBR synthesized images. It is shown that MW-PSNR achieves much higher correlation with human judgment compared to the state-of-the-art image quality measures in this context.

1 April 2011 in IEEE Transactions on Image Processing
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Journal Article
Closed access
DĆDubravko Ćulibrk
Dubravko Ćulibrk
MMMilan Mirković
Milan Mirković
VZVladimir Zlokolica
Vladimir Zlokolica
MPMaja Pokrić
Maja Pokrić
VCVladimir Crnojević
Vladimir Crnojević
DKDragan D. Kukolj
Dragan D. Kukolj
Design of algorithms that are able to estimate video quality as perceived by human observers is of interest for a number of applications. Depending on the video content, the artifacts introduced by the coding process can be more or less pronounced and diversely affect the quality of videos, as estimated by humans. While it is well understood that motion affects both human attention and coding quality, this relationship has only recently started gaining attention among the research community, when video quality assessment (VQA) is concerned. In this paper, the effect of calculating several objective measure features, related to video coding artifacts, separately for salient motion and other regions of the frames of the sequence is examined. In addition, we propose a new scheme for quality assessment of coded video streams, which takes into account salient motion. Standardized procedure has been used to calculate the Mean Opinion Score (MOS), based on experiments conducted with a group of non-expert observers viewing standard definition (SD) sequences. MOS measurements were taken for nine different SD sequences, coded using MPEG-2 at five different bit-rates. Eighteen different published approaches related to measuring the amount of coding artifacts objectively on a single-frame basis were implemented. Additional features describing the intensity of salient motion in the frames, as well as the intensity of coding artifacts in the salient motion regions were proposed. Automatic feature selection was performed to determine the subset of features most correlated to video quality. The results show that salient-motion-related features enhance prediction and indicate that the presence of blocking effect artifacts and blurring in the salient regions and variance and intensity of temporal changes in non-salient regions influence the perceived video quality.