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Publikacije (33235)

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Sandra Stojić, Zoltan Nadasdy

Time is a fundamental dimension of our perception and mental construction of reality. It enables resolving changes in our environment without a direct sensory representation of elapsed time. Therefore, the concept of time is inferential by nature, but the units of subjective time that provide meaningful segmentation of the influx of sensory input remain to be determined. In this review, we posit that events are the construal instances of time perception as they provide a reproducible and consistent segmentation of the content. In that light, we discuss the implications of this proposal by looking at “events” and their role in subjective time experience from cultural anthropological and ontogenetic perspectives, as well as their relevance for episodic memory. Furthermore, we discuss the significance of “events” for the two critical aspects of subjective time—duration and order. Because segmentation involves parsing event streams according to causal sequences, we also consider the role of causality in developing the concept of directionality of mental timelines. We offer a fresh perspective on representing past and future events before age 5 by an egocentric bi-directional timeline model before acquiring the allocentric concept of absolute time. Finally, we illustrate how the relationship between events and durations can resolve contradictory experimental results. Although “time” warrants a comprehensive interdisciplinary approach, we focus this review on “time perception”, the experience of time, without attempting to provide an all encompassing overview of the rich philosophical, physical, psychological, cognitive, linguistic, and neurophysiological context.

Armin Zunic, E. Sokic, N. Osmic, Isam Vrce, A. Salihbegovic

This paper explores the application of FPGA programmable structures in the field of digital image signal processing (ISP). FPGAs offer high flexibility, speed and parallelism, making them ideal for general digital signal processing (DSP), as well as specific ISP tasks. The paper utilizes standard ISP algorithms such as morphological operations, filtering and edge detection to compare practical implementations of FPGA and CPU-based compute engines. Through illustrative examples and empirical results, we demonstrate the distinct advantages of employing FPGA for these use-cases, and contrast them with traditional CPU approaches, clearly showing FPGA capacity to significantly accelerate execution. The challenges that arise from resource-limited IOT-class hardware configurations are highlighted in the paper, namely resource optimization, memory management and maximal frequency.

This paper focuses on the design and implementation of a discrete digital PID (Proportional - Integral - Derivative) controller utilizing an FPGA (Field Programmable Gate Arrays) platform, which inherently supports parallel implementation of algorithms. Typically, cost-effective FPGA boards lacks peripherals, such as analog inputs and outputs, so they need to be added externally. The main hypothesis is that a DC motor system can be controlled with a low-cost variant of FPGA-based PID controllers. Therefore, an I2C (Inter-Integrated Circuit) based AD (Analog-to-digital) converter is added as input, while PWM (Pulse width modulation) based output signal is used as an output. The effectiveness of the designed regulator is demonstrated on an example of a DC (direct current) motor control. Additionally, for control and monitoring purposes, the FPGA is connected to the PC using the UART (Universal Asynchronous Receiver Transmitter) protocol. Experimental results indicate that the FPGA-based PID implementation offers solid performance.

E. Sokic, Isam Vrce, Armin Zunic, N. Osmic, A. Salihbegovic

The paper presents an automated method for solving traditional single side 2D jigsaw puzzles, focusing solely on shape features. Termed as semi-apictorial puzzles, our approach utilizes pictorial content solely for image segmentation, not for puzzle matching. Through enhancements in background separation, corner extraction, and feature matching, our method simplifies and accelerates puzzle reconstruction. A key contribution is the introduction of an edge matching technique that employs approximate triangles to evaluate a possible match, which notably improves computational efficiency and reduces algorithm complexity. Experimental results demonstrate that the proposed method outperforms existing solutions, enabling the handling of a larger puzzles within a reasonable timeframe.

This paper presents the development and implementation of a flexible industrial machine model for automated visual inspection, called ETFCam, designed to improve the learning outcomes of electrical engineering students in the field of machine vision and robotics. Unlike prefabricated didactic models, which are typically “closed” systems with a predefined set of experiments, custom didactic systems for teaching and training built from scratch tend to be more flexible and provide a deeper insight in engineering, machine design and planning, while being more cost-effective. The proposed system is based on a 3DOF stepper motor-based manipulator, a DC motor driven conveyor, a pneumatic actuated gripper and a machine vision system. The paper discusses several applications of such a system in an educational environment, with a special focus on machine vision applications. Due to the fact that the system is versatile, open, modular, and easy to upgrade, it has unlimited potential and possibilities for further development. In addition, it provides students with a perfect testbed for learning new engineering skills in many areas such as schematic drawing and understanding, PLC based control, sensing, and machine vision.

This paper introduces twisting sliding mode control method (TWSMC) to track 3D trajectories of a quadrotor unmanned aerial vehicle (UAV) exposed to bounded disturbances and perturbations. The key idea behind TWSMC is to introduce a nonlinear twisting term into the sliding surface design, which enables the system to switch between different sliding modes (SMs) smoothly, thereby reducing the chattering phenomenon and improving control performance. Moreover, a high-gain adaptation (HGA) algorithm is adopted in the TWSMC scheme to additionally attenuate the chattering effect, where the switching control gain increases during the convergent phase and decreases in the sliding phase. Through the comprehensive simulation study, it is shown that the proposed approach exhibits improved robustness and performance in tracking a reference under disturbances and perturbations.

A. Cagol, Mario Ocampo-Pineda, Po-Jui Lu, Matthias Weigel, M. Barakovic, L. Melie-García, Xinjie Chen, Antoine Lutti et al.

Background and Objectives In patients with multiple sclerosis (PwMS), thalamic atrophy occurs during the disease course. However, there is little understanding of the mechanisms leading to volume loss and of the relationship between microstructural thalamic pathology and disease progression. This cross-sectional and longitudinal study aimed to comprehensively characterize in vivo pathologic changes within thalamic microstructure in PwMS using advanced multiparametric quantitative MRI (qMRI). Methods Thalamic microstructural integrity was evaluated using quantitative T1, magnetization transfer saturation, multishell diffusion, and quantitative susceptibility mapping (QSM) in 183 PwMS and 105 healthy controls (HCs). The same qMRI protocol was available for 127 PwMS and 73 HCs after a 2-year follow-up period. Inclusion criteria for PwMS encompassed either an active relapsing-remitting MS (RRMS) or inactive progressive MS (PMS) disease course. Thalamic alterations were compared between PwMS and HCs and among disease phenotypes. In addition, the study investigated the relationship between thalamic damage and clinical and conventional MRI measures of disease severity. Results Compared with HCs, PwMS exhibited substantial thalamic alterations, indicative of microstructural and macrostructural damage, demyelination, and disruption in iron homeostasis. These alterations extended beyond focal thalamic lesions, affecting normal-appearing thalamic tissue diffusely. Over the follow-up period, PwMS displayed an accelerated decrease in myelin volume fraction [mean difference in annualized percentage change (MD-ApC) = −1.50; p = 0.041] and increase in quantitative T1 (MD-ApC = 0.92; p < 0.0001) values, indicating heightened demyelinating and neurodegenerative processes. The observed differences between PwMS and HCs were substantially driven by the subgroup with PMS, wherein thalamic degeneration was significantly accelerated, even in comparison with patients with RRMS. Thalamic qMRI alterations showed extensive correlations with conventional MRI, clinical, and cognitive disease burden measures. Disability progression over follow-up was associated with accelerated thalamic degeneration, as reflected by enhanced diffusion (β = −0.067; p = 0.039) and QSM (β = −0.077; p = 0.027) changes. Thalamic qMRI metrics emerged as significant predictors of neurologic and cognitive disability even when accounting for other established markers including white matter lesion load and brain and thalamic atrophy. Discussion These findings offer deeper insights into thalamic pathology in PwMS, emphasizing the clinical relevance of thalamic damage and its link to disease progression. Advanced qMRI biomarkers show promising potential in guiding interventions aimed at mitigating thalamic neurodegenerative processes.

Matthias Licheri, M. F. Licheri, K. Mehinagic, E. Radulovic, N. Ruggli, Ronald Dijkman

African swine fever virus (ASFV) has been spreading through Europe, Asia, and the Caribbean after its introduction in Georgia in 2007 and, due to its particularly high mortality rate, poses a continuous threat to the pig industry. The golden standard to trace back the ASFV is whole genome sequencing, but it is a cost and time-intensive methodology. A more efficient way of tracing the virus is to amplify only specific genomic regions relevant for genotyping. This is mainly accomplished by amplifying single amplicons by PCR followed by Sanger sequencing. To reduce costs and processivity time, we evaluated a multiplex PCR based on the four primer sets routinely used for ASFV genotyping (B646L, E183L, B602L, and intergenic I73R-I329L), which was followed by Nanopore ligation-based amplicon sequencing. We show that with this protocol, we can genotype ASFV DNA originating from different biological matrices and correctly classify multiple genotypes and strains using a single PCR reaction. Further optimization of this method can be accomplished by adding or swapping the primer sets used for amplification based on the needs of a specific country or region, making it a versatile tool that can speed up the processing time and lower the costs of genotyping during ASFV outbreaks.

Lejla Ušanović, Lejla Lasić, N. Pojskić, Dalila Destanović, Jasna Hanjalić Kurtović, Belma Kalamujić Stroil

Borrelia burgdorferi sensu lato complex comprises 20 species, from which B. afzelii, B. garinii, B. burgdorferi sensu stricto, B. bavariensis, and B. spielmanii are directly associated with Lyme borreliosis, while B. bissettiae, B. lusitaniae, and B. valaisiana were detected in individual cases. Their main vector in Europe is the hard tick species Ixodes ricinus. To date, two species, B. spielmanii and B. lusitaniae, have been molecularly detected in Bosnia and Herzegovina. To test for the presence of other Borrelia species, we performed nested PCR targeting intergenic region rrf (5S) - rrl (23S) on DNA isolates from 49 ticks collected from vegetation by flagging method and 43 removed from humans in The Center for Emergency Medical Assistance of the Sarajevo Canton and The Healthcare Centers of the Sarajevo Canton. Borrelia species were detected by one-directional Sanger sequencing of the amplified region using the same forward primer as in PCR. Out of six Borrelia species detected in the present study, this is the first record of B. afzelii, B. garinii, B. burgdorferi s.s. B. bavariensis, and B. valaisiana in Bosnia and Herzegovina.

M. Fočak, M. Mitrašinović-Brulić, Filip Filipić, Damir Suljevic

CCl4 causes oxidative injury, fatty degeneration, fibrosis of the liver, renal failure, and even hepatocellular and renal carcinoma. Certain substances have the potential to neutralize the harmful effects of CCl4, so it will lead to numerous beneficial effects. Melatonin (MEL) is a powerful antioxidant that regulates circadian rhythm and has beneficial effects on organism; tryptophan (TRP) is its precursor necessary for the synthesis of MEL. The aim of the current study was to determine whether MEL and TRP, have protective effects during subchronic application of CCl4 to the liver and kidneys. Results suggest that CCl4 led to decrease of total proteins, albumins, globulins, erythrocytes, hemoglobin, and hematocrit; and increase of creatinine, AST, ALT values, and leukocytes. MEL and TRP both showing protective effects on regulation of serum proteins, albumins, globulins, A/G, AST, ALT, and creatinine levels. TRP had been shown to have potential in regulation of disbalanced hematological parameters caused by CCl4. TRP had beneficial effects on hepatocyte morphology in term of beaded chromatin and preserved cell morphology. Overall, oral supplementation of TRP had better protective effects on liver/kidneys compared to MEL.

A. Dervišević, Almir Fajkić, Elmedina Jahić, L. Dervišević, Zurifa Ajanović, E. Ademović, Asija Začiragić

Objective To evaluate the systemic immune-inflammation (SII) index in patients with rheumatoid arthritis (RA) stratified by systemic inflammatory status. Methods Seropositive patients with RA (n=58) were divided into two groups based on serum hs-C-reactive protein (hs-CRP) levels: RA patients with hs-CRP levels of at or 3 mg/L or above (high systemic inflammatory status; n=38) and RA patients with hs-CRP levels of less than 3 mg/L (low systemic inflammatory status; n=20). The control group comprised 31 healthy individuals. Blood samples were tested for the next parameters: leukocytes, neutrophilic granulocytes, lymphocytes, thrombocytes [platelet (PLT)], high-sensitivity hs-CRP, sed rate [erythrocyte sedimentation rate (ESR)], neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR). The SII index was derived as Neu x PLT/Lym. Results In patients with RA, the SII index was elevated compared with that of healthy individuals and positively correlated with hs-CRP, erythrocyte sedimentation rate, NLR, MLR, PLR, tender joint count, and swollen-to-tender joint count ratio. Patients with RA who had hs-CRP levels of 3 mg/L above exhibited a statistically significant increase in the SII compared with those with hs-CRP levels below 3 mg/L. Additionally, within the cohort of RA patients with hs-CRP levels at or above 3 mg/L, a positive correlation was found between the SII index and both NLR and PLR. The SII index was positively correlated with NLR, MLR, and PLR in RA patients with hs-CRP levels below 3 mg/L. The cut-off point of the SII index for distinguishing between RA cases with hs-CRP levels 3 mg/L and those with hs-CRP levels 3 mg/L or higher was ≥323.4, with a sensitivity of 77.6% and a specificity of 54.8%. Conclusions The serum SII index can be a potentially useful marker for evaluating the inflammatory process and clinical progression of RA.

Kenan Turbic, Martin Kasparick, Sławomir Stańczak

This letter presents simple analytical expressions for the spatial and temporal correlation functions in channels with von Mises-Fisher (vMF) scattering. In contrast to previous results, the expressions presented here are exact and based only on elementary functions, clearly revealing the impact of the underlying parameters. The derived results are validated by a comparison against numerical integration result, where an exact match is observed. To demonstrate their utility, the presented results are used to analyze spatial correlation across different antenna array geometries and to investigate temporal correlation of a fluctuating radar signal from a moving target.

Kenan Turbic, Martin Kasparick, Sławomir Stańczak

This paper presents an analytical analysis of the Doppler spectrum in von Mises-Fisher (vMF) scattering channels. A closed-form expression for the Doppler spectrum is derived and used to investigate the impact of vMF scattering parameters, i.e., the mean direction and the degree of concentration of scatterers. The spectrum is observed to exhibit exponential behavior for the mobile antenna motion parallel to the mean direction of scatterers, while conforming to a Gaussian-like shape for the perpendicular motion. The validity of the obtained results is verified by comparison against the results of Monte Carlo simulations, where an exact match is observed.

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