Showing papers by "University of Rijeka published in 2023"

On the Use of a Genetic Algorithm for Determining Ho–Cook Coefficients in Continuous Path Planning of Industrial Robotic Manipulators

Abstract: Path planning is one of the key steps in the application of industrial robotic manipulators. The process of determining trajectories can be time-intensive and mathematically complex, which raises the complexity and error proneness of this task. For these reasons, the authors tested the application of a genetic algorithm (GA) on the problem of continuous path planning based on the Ho–Cook method. The generation of trajectories was optimized with regard to the distance between individual segments. A boundary condition was set regarding the minimal values that the trajectory parameters can be set in order to avoid stationary solutions. Any distances between segments introduced by this condition were addressed with Bezier spline interpolation applied between evolved segments. The developed algorithm was shown to generate trajectories and can easily be applied for the further path planning of various robotic manipulators, which indicates great promise for the use of such algorithms.

Reply on RC1

Abstract: To examine the effectiveness of various technical solutions for minimizing the adverse effects of salt water intrusion in lake Vrana, Croatia, a reliable mathematical model for describing the exchange of fresh and salt water between the lake and its surroundings is needed. For this purpose, a system of two ordinary and nonlinear differential equation is used. The variable coefficients represents hydraulic conductivity functions that are used to quantify groundwater flow and should be appropriately estimated by relying on data obtained by in situ measurements. In the abstract space of all possible hydraulic conductivity functions, the method of particle swarm optimization was used to search for functions which will minimize the difference between the predicted (modeled) and realized (measured) water surface elevation in the lake through the time span of 5 years (which includes relevant hydrological extremes – droughts and floods). The associated procedure requires the parameterization of conductivity functions which will define the number of dimensions of the search space. Although the considered mass exchange processes are significantly nonlinear, and the parametrization of hydraulic conductivity functions can define a search space with relatively large number of dimensions (60 dimensions were used to estimate the hydraulic conductivity functions of Vrana lake), the presented example confirms the effectiveness of the proposed approach.

Multimessenger Characterization of Markarian 501 during Historically Low X-Ray and γ-Ray Activity

Abstract: Abstract We study the broadband emission of Mrk 501 using multiwavelength observations from 2017 to 2020 performed with a multitude of instruments, involving, among others, MAGIC, Fermi's Large Area Telescope (LAT), NuSTAR, Swift, GASP-WEBT, and the Owens Valley Radio Observatory. Mrk 501 showed an extremely low broadband activity, which may help to unravel its baseline emission. Nonetheless, significant flux variations are detected at all wave bands, with the highest occurring at X-rays and very-high-energy (VHE) γ -rays. A significant correlation (>3 σ ) between X-rays and VHE γ -rays is measured, supporting leptonic scenarios to explain the variable parts of the emission, also during low activity. This is further supported when we extend our data from 2008 to 2020, and identify, for the first time, significant correlations between the Swift X-Ray Telescope and Fermi-LAT. We additionally find correlations between high-energy γ -rays and radio, with the radio lagging by more than 100 days, placing the γ -ray emission zone upstream of the radio-bright regions in the jet. Furthermore, Mrk 501 showed a historically low activity in X-rays and VHE γ -rays from mid-2017 to mid-2019 with a stable VHE flux (>0.2 TeV) of 5% the emission of the Crab Nebula. The broadband spectral energy distribution (SED) of this 2 yr long low state, the potential baseline emission of Mrk 501, can be characterized with one-zone leptonic models, and with (lepto)-hadronic models fulfilling neutrino flux constraints from IceCube. We explore the time evolution of the SED toward the low state, revealing that the stable baseline emission may be ascribed to a standing shock, and the variable emission to an additional expanding or traveling shock.

Linearization for Difference Equations with Infinite Delay

Abstract: In this article, we construct a conjugacy map for a linear difference equation with infinite delay and corresponding nonlinear perturbation. We also prove that the conjugacy map is one-to-one with some additional conditions. As an application of our result, we show that the cases of (uniform) exponential dichotomy follow from our result.

Reply on CC1

Abstract: To examine the effectiveness of various technical solutions for minimizing the adverse effects of salt water intrusion in lake Vrana, Croatia, a reliable mathematical model for describing the exchange of fresh and salt water between the lake and its surroundings is needed. For this purpose, a system of two ordinary and nonlinear differential equation is used. The variable coefficients represents hydraulic conductivity functions that are used to quantify groundwater flow and should be appropriately estimated by relying on data obtained by in situ measurements. In the abstract space of all possible hydraulic conductivity functions, the method of particle swarm optimization was used to search for functions which will minimize the difference between the predicted (modeled) and realized (measured) water surface elevation in the lake through the time span of 5 years (which includes relevant hydrological extremes – droughts and floods). The associated procedure requires the parameterization of conductivity functions which will define the number of dimensions of the search space. Although the considered mass exchange processes are significantly nonlinear, and the parametrization of hydraulic conductivity functions can define a search space with relatively large number of dimensions (60 dimensions were used to estimate the hydraulic conductivity functions of Vrana lake), the presented example confirms the effectiveness of the proposed approach.

Primary Nodal Unclassifiable CD20 Negative Diffuse Large B-cell Lymphoma With Dual <i>IgK</i> and <i>TCR</i> Gene Rearrangement: A Diagnostic Challenge

Abstract: Non-Hodgkin lymphomas are most frequently classified based on the lineage marker expression. However, lymphomas with aberrant marker expression as well as monoclonal IgH/IgΚ and TCR gene rearrangements may co-exist which can be misleading and confusing. Primary CD20 negative diffuse large B-cell lymphomas (DLBCL) represent a rare entity, and they account for 1% to 3% of cases. However, some CD20 negative DLBCLs could not be classified into known variants, creating both diagnostic and therapeutic dilemma’s. Primary CD20 negative DLBCL are more likely to have a non-germinal centre subtype, a higher proliferation index, more frequent extra-nodal involvement, a poorer response, and poorer prognosis to conventional treatment compared to CD20 positive DLBCL. A 66- year-old postmenopausal lady, presented with palpable, bilateral neck lymphadenopathy and difficulty swallowing. She also had left leg lymphoedema, poor appetited, fatigue and weight loss. Her symptoms lasted approximately 1 month. After histological, immunohistochemical and clonality analysis of the lymph node the patient was diagnosed with primary nodal CD20 and PAX-5 negative DLBCL with dual immunoglobulin light-chain kappa ( IgK) and T-cell receptor ( TCR) gene rearrangement. This unusual and unique case presented a diagnostic challenge because it was CD20 and PAX-5 negative, had dual IgK and TCR gene rearrangement and, it could not be classified within the known and well established CD20 negative DLBCL variants. Describing such cases emphasises the fact that lymphomas unclassifiable within known variants of CD20 negative DLBCL do exist and that range and heterogeneity of CD20 negative DLBCL continues to evolve, and pathologist should be aware of these uncommon, atypical mature B-cell neoplasms.

Cross-Sectional Use of Vascular, Blood-Based Biomarkers—Augmenting Postmortem

Abstract: Many assets of clinical medicine, such as clinical chemistry and diagnostic imaging, make clinical diagnosis outstanding compared to postmortem diagnosis. An assessment of functional status certainly has priority over the postmortem, cross-sectional use of diagnostic tests and laboratory equipment. In addition, the cost of these tools is sometimes steep, and their use does not always fit into a reasonable cost–benefit ratio. However, sometimes postmortem observations, such as inflammation, pulmonary edema, or infiltration and cerebral swelling, cannot be explained without implementing immunohistochemical markers for postmortem diagnosis. Introducing blood-based biomarkers in postmortem care could significantly reduce the rates of inconclusive postmortems and discrepancies in autopsy findings and clinical diagnoses. This is particularly relevant in the scope of vascular pathology, considering the great burden of vascular diseases in overall mortality. Expanding traditional autopsy with blood-based (circulating) biomarkers to avoid invasive postmortem examination would have cultural, religious, and potential economic advantages. All of the target molecules are discussed in the context of the process they up-regulate or down-regulate and which turns out to be the final cause of death. Ultimately, it is evident that further studies are needed to provide concrete validation for a combination of markers on a specific case order to reach a postmortem diagnosis with or without clinical records.

Strategies for Green Shipbuilding Design and Production Practices Focused on Reducing Microplastic Pollution Generated during Installation of Plastic Pipes

Abstract: In recent years, microplastic pollution has been given increasing attention in marine environments due to the hazard it poses for aquatic organisms. Plastic pipes are now being widely used in shipbuilding, and due to easy processing, they are often installed directly on ships. This includes the cutting and preparation of pipes for welding, which produces plastic debris in the immediate vicinity of the marine environment. Such plastic debris can easily become airborne, and when it is ultimately deposited into the water, it can be a contributor to marine microplastic pollution. This could be reduced if, during the design stage and outfitting stage, engineers would take into consideration ecological aspect of their design, which is currently not the case. Therefore, in this paper, suggestions for green shipbuilding practices, focused on the piping design and production phases, are presented for the possible reduction in operations with plastic pipes, with the main aim of reducing microplastic pollution. Based on these recommendations, additional economic and feasibility investigations are needed to obtain optimal results, which would be beneficial both from a manufacturing and ecological perspective.

On the Robustness Property of Nonuniform Exponential Dichotomies

Abstract: Assume that a sequence $$(A_n)_{n\in \mathbb Z}$$ of bounded linear operators on a Banach space X admits a nonuniform exponential dichotomy with exponents $$\lambda >0$$ and $$\epsilon \ge 0$$ . We formulate sufficient conditions under which a perturbed sequence $$(A_n+B_n)_{n\in \mathbb Z}$$ admits a nonuniform exponential dichotomy with the same exponents.

Key dimensions of memorable gastronomic experience: application of Q-methodology

Abstract: Gastronomy is considered a vital resource and is a key component of a memorable tourism experience. Some studies have explored memorable gastronomic experience (MGE) but have been unable to provide a comprehensive overview of the topic. The purpose of this research is to advance knowledge in relation to MGE. The Q-methodology of research synthesis (QMRS) was applied to identify MGE dimensions and support qualitative and quantitative approaches within the research process. The findings of the study contribute to a greater understanding of MGE by providing a conceptual model.

Aesthetic Cognitivism and Serialized Television Fiction

Abstract: Abstract In this article, I defend the cognitive value of certain generic television series. Unlike media and television scholars, who have been appreciative of the informative capacity of television fiction, philosophers have been less willing to acknowledge the way in which these works contribute to our understanding of our social reality. My aim here is to provide one such account, grounded in aesthetic cognitivism, that is, the view that fiction is a source of knowledge. Focusing on crime and courtroom dramas, I start by offering some examples of the cognitive benefits available in some of these series and I argue that the more beneficial cases establish superior mimetic relations with reality, enhancing their capacity to present ethically challenging issues. I then examine whether the fictional dimension of these works presents an obstacle to their informative potential and I conclude that it does not. A central aspect of my account is the claim that the degree of cognitive benefit depends on the underlying narrative strategy of the series. Specifically, there are clues in any given show, including the treatment of ongoing characters, which signal the extent to which it can be taken as mimetically reliable and thus, cognitively valuable. I complete my account by addressing anti-cognitivists’ arguments which call to doubt the informative aspect of television series and their capacity to address ethical concerns.

Implementation and Cost-Effectiveness of Blockchain Technology within the IP Ecosystems

Abstract: The Fourth Industrial Revolution (Industry 4.0) enables the new digital economy by merging technologies such as blockchain, big data, artificial intelligence, the Internet of Things (IoT), and other emerging technologies through digital transformation. Blockchain technology is among the emerging technologies that are affecting the ways of business operationalization through the automatization of tasks, but also the management of intellectual property rights (IPRs) protection process. The digital economy has an important role in both social and as an engine for economic growth while the IPRs have an important role in the development of the digital economy. The aim of this paper is to investigate and analyze the cost-effectiveness and positive impact of blockchain technologies adoption and implementation in IPRs protection process within the IP ecosystem.

10th Anniversary of ICL Adriatic-Balkan Network and 5th Regional Symposium on Landslides

Abstract: Abstract The Adriatic-Balkan Network (ABN) was established in January 2012 as one of regional networks in the framework of International Consortium on Landslides (ICL) and its 10th Anniversary was concluded with 5th Regional Symposium on Landslides in Adriatic-Balkan Region (ReSyLAB) in Rijeka, Croatia, in March 2022. The Adriatic-Balkan Network was formally established during the 14th Serbian Symposium on Engineering Geology and Geotechnics in Belgrade in September 2012 based on the Proposal of the ICL Adriatic-Balkan Network that was approved at the 10th Anniversary Meeting of ICL held in Kyoto, Japan, in January 2012. The main outcome of the Adriatic-Balkan Network activity is organization of biannual Regional Symposiums on Landslides, organized in Zagreb, Croatia, 2013; Belgrade, Serbia, 2015; Ljubljana, Slovenia, 2017; Sarajevo, Bosnia and Herzegovina, 2019; and the last one in Rijeka, Croatia in March 2022. In this paper, the establishment, objectives and activities of Adriatic-Balkan Network (ABN) within last ten years were presented as well as main outcomes of the 5th ReSyLAB held in Rijeka, Croatia, in March 2022.

Application of AI in Histopathological Image Analysis

Abstract: Over the past decade, improvements in image analysis methods and substantial advancements in the processing power have allowed the development of powerful computer-aided analytical approaches to medical data. Tissue histology slides can now be scanned and preserved in digital form, thanks to the recent introduction of entire slide digital scanners. In such a form, they can serve as input data for Artificial Intelligence (AI) algorithms that can speed up standard procedures for histology analysis with high accuracy and precision. This research aimed to create an automated system based on AI for histopathological image analysis. The first step was normalizing H&E-stain images and then using them as input to the convolutional neural network. The best results are achieved using ResNet50 with the highest AUC value of 0.98 (±σ = 0.02). Such an approach proved to be successful in analyzing histopathological images.

Reply on RC2

Abstract: To examine the effectiveness of various technical solutions for minimizing the adverse effects of salt water intrusion in lake Vrana, Croatia, a reliable mathematical model for describing the exchange of fresh and salt water between the lake and its surroundings is needed. For this purpose, a system of two ordinary and nonlinear differential equation is used. The variable coefficients represents hydraulic conductivity functions that are used to quantify groundwater flow and should be appropriately estimated by relying on data obtained by in situ measurements. In the abstract space of all possible hydraulic conductivity functions, the method of particle swarm optimization was used to search for functions which will minimize the difference between the predicted (modeled) and realized (measured) water surface elevation in the lake through the time span of 5 years (which includes relevant hydrological extremes – droughts and floods). The associated procedure requires the parameterization of conductivity functions which will define the number of dimensions of the search space. Although the considered mass exchange processes are significantly nonlinear, and the parametrization of hydraulic conductivity functions can define a search space with relatively large number of dimensions (60 dimensions were used to estimate the hydraulic conductivity functions of Vrana lake), the presented example confirms the effectiveness of the proposed approach.