Прегледај по Аутор "Nedić, Dragana"

Сада се приказује 1 - 2 од 2
  • Сличица
    Ставка
    Predictive Modeling of Delay in an LTE Network by Optimizing the Number of Predictors Using Dimensionality Reduction Techniques
    (MDPI, 2023) Stojčić, Mirko; Banjanin, Milorad K.; Vasiljević, Milan; Nedić, Dragana; Stjepanović, Aleksandar; Danilović, Dejan; Puzić, Goran
    Delay in data transmission is one of the key performance indicators (KPIs) of a network. The planning and design value of delay in network management is of crucial importance for the optimal allocation of network resources and their performance focuses. To create optimal solutions, predictive models, which are currently most often based on machine learning (ML), are used. This paper aims to investigate the training, testing and selection of the best predictive delay model for a VoIP service in a Long Term Evolution (LTE) network using three ML techniques: Multilayer Perceptron (MLP), Support Vector Machines (SVM) and k-Nearest Neighbors (k-NN). The space of model input variables is optimized by dimensionality reduction techniques: RReliefF algorithm, Backward selection via the recursive feature elimination algorithm and the Pareto 80/20 rule. A three-segment road in the geo-space between the cities of Banja Luka (BL) and Doboj (Db) in the Republic of Srpska (RS), Bosnia and Herzegovina (BiH), covered by the cellular network (LTE) of the M:tel BL operator was chosen for the case study. The results show that the k-NN model has been selected as the best solution in all three optimization approaches. For the RReliefF optimization algorithm, the best model has six inputs and the minimum relative error (RE) RE = 0.109. For the Backward selection via the recursive feature elimination algorithm, the best model has four inputs and RE = 0.041. Finally, for the Pareto 80/20 rule, the best model has 11 inputs and RE = 0.049. The comparative analysis of the results concludes that, according to observed criteria for the selection of the final model, the best solution is an approach to optimizing the number of predictors based on the Backward selection via the recursive feature elimination algorithm.
  • Сличица
    Ставка
    Spectral properties of some differential operators of Sturm-Liouville type with homogeneous delay
    (2022) Nedić, Dragana; Čatrnja, Elmir
    In this paper we observe the operator D2 = D2(h,H, q, ), h,H 2 R = R [ {−1,1}, q(x) 2 L2 [0, ], 2 (0, 1) and construct and partially transform its characteristic function. Those transformations enable more complete asymptotic decomposition of the zeroes and eigenvalues of the operator. The goal of this paper is to contribute to the development of the spectral theory of differ-ential operators with homogeneous delay.