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Benchmarking global optimization techniques for unmanned aerial vehicle path planning
(PERGAMON-ELSEVIER SCIENCE LTD, 2025-12-01) Shehadeh, Mhd Ali; Kůdela, Jakub
The Unmanned Aerial Vehicle (UAV) path planning problem is a complex optimization problem in the field of robotics. In this paper, we investigate the possible utilization of this problem in benchmarking global optimization methods. We devise a problem instance generator and pick 56 representative instances, which we compare to established benchmarking suits through Exploratory Landscape Analysis to show their uniqueness. For the computational comparison, we select fourteen well-performing global optimization techniques from both subfields of stochastic algorithms (evolutionary computation methods) and deterministic algorithms (Dividing RECTangles, or DIRECT-type methods). The experiments were conducted in settings with varying dimensionality and computational budgets. The results were analyzed through several criteria (number of best-found solutions, mean relative error, Friedman ranks) and utilized established statistical tests. The best-ranking methods for the UAV problems were almost universally the top-performing evolutionary techniques from recent competitions on numerical optimization at the Institute of Electrical and Electronics Engineers Congress on Evolutionary Computation. Lastly, we discussed the variable dimension characteristics of the studied UAV problems that remain still largely under-investigated. The code and results are available at a Zenodo repository https://doi.org/10.5281/zenodo.15424080.
Analysing plate fixation of a comminuted fracture of the proximal ulna in relation to the elbow joint: a finite element study
(BMC, 2025-07-28) Šafran, Jindřich; Pavlacký, Tomáš; Marcián, Petr; Herůfek, Radim; Veselý, Radek
This study investigated the biomechanical behavior of four different screw configurations used to fix comminuted proximal ulna fractures with a locking compression plate (LCP), via a detailed finite element model based on realistic anatomical geometry. The model incorporated realistic anatomical geometry including both cortical and cancellous bone, soft tissue constraints, and loading conditions representing the physiological self-weight of the forearm, with the humerus fixed at its proximal end. The stress distribution on the plate, strain intensity within the bone tissue, and interfragmentary motion (IFM) between fracture fragments were evaluated for each configuration. The results indicate that all the tested configurations provide adequate stability under normal loading conditions, with no risk of material failure. However, excessive stress concentrations were observed in specific screw regions depending on the configuration, particularly when proximal screws anchoring the olecranon (e.g. screws 2 and 3 in Variant 3) were omitted. Strain analysis revealed moderate physiological bone loading across variants, whereas IFM assessment highlighted the importance of securing the coronoid and apical fragments to prevent compromised healing. These findings suggest that a specific reductions in osteosynthetic material, such as omitting certain diaphyseal screws while maintaining crucial olecranon and coronoid fixation, may provide sufficient fracture stabilisation under the modelled conditions, potentially minimising implant-related complications. This modelling approach offers a valuable tool for preclinical assessment of osteosynthesis strategies and supports future comparative research on fixation methods with varying biomechanical properties.
CpX Hunter web tool allows high-throughput identification of CpG, CpA, CpT, and CpC islands: A case study in Drosophila genome
(Elsevier, 2025-05-21) Bartas, Martin; Petrovič, Michal; Brázda, Václav; Trenz, Oldřich; Ďurčanský, Aleš; Šťastný, Jiří
With continuous advances in DNA sequencing methods, accessibility to high-quality genomic information for all living organisms is ever-increasing. However, to interpret this information effectively and formulate hypotheses, users often require higher level programming skills. Therefore, the generation of web-based tools is becoming increasingly popular. CpG island regions in genomes are often found in gene promoters and are prone to DNA methylation, with their methylation status determining if a gene is expressed. Notably, understanding the biological impact of CpX modifications on genomic regulation is becoming increasingly important as these modifications have been associated with diseases such as cancer and neurodegeneration. However, there is currently no easy-to-use, scalable tool to detect and quantify CpX islands in full genomes. We have developed a Java-based web server for CpX island analyses that benefits from the DNA Analyzer Web server environment and overcomes several limitations. For a pilot demonstration study, we selected a well-described model organism Drosophila melanogaster. Subsequent analysis of the obtained CpX islands revealed several interesting and previously undescribed phenomena. One of them is the fact, that nearly half of long CpG islands were located on chromosome X, and that long CpA and CpT islands were significantly overrepresented at the subcentromeric regions of autosomes (chr2 and chr3) and also on chromosome Y. Wide genome overlays of predicted CpX islands revealed their co-occurrence with various (epi)genomics features comprising cytosine methylations, accessible chromatin, transposable elements, or binding of transcription factors and other proteins. CpX Hunter is freely available as a web tool at: https://bioinformatics.ibp.cz/ #/analyse/cpg.
Towards efficient waste management: identification of waste flow chains in micro-regional detail through monitored data
(Springer, 2024-06-18) Němcová, Lucie; Pluskal, Jaroslav; Šomplák, Radovan; Kůdela, Jakub
Countries around the world are gradually implementing the transition to a circular economy in waste management. This effort should be initiated already at the waste producers. It is necessary to plan and monitor waste management in as much detail as possible, i.e. at the level of micro-regions. At present, only indicators at the national level are analysed, as more detailed data at the micro-regional level are often not available or are burdened with significant errors and inconsistencies. The calculation of waste management indicators for micro-regions will allow to identify the potential for increasing material or energy recovery and to plan the necessary infrastructure directly to these locations instead of blanket and often ineffective legislative actions. This paper presents an approach for determining the producer-treatment linkage, i.e., provides information about each produced waste, where it was treated, and in what way. Such information is often not available based on historical waste management data as there are repeated waste transfers and often aggregated within a micro-region. The network flow approach is based on an iterative procedure combining a simulation with multi-criteria optimization. The chosen criteria replicate expert estimates in investigated issue such as minimum flow splitting, and minimum transfer micro-regions. A data reconciliation is performed where the deviation from all simulations is minimized, given that the capacity constraints of nodes and arcs resulting from the database must be satisfied. The approach is tested on a generated sample task to evaluate the precision and time complexity of the developed tool. Finally, the presented approach is applied to address a case study in the Czech Republic, within which it is possible to identify treatment location and methods for waste from individual regions.
Materials That Do Not Form Any Defects After WEDM
(MDPI, 2024-12-06) Mouralová, Kateřina; Fries, Jiří; Beneš, Libor; Houška, Pavel
Wire Electric Discharge Machining (WEDM) is an unconventional machining technology that uses electrical impulses to generate very high temperatures to cut material. The WEDM process hence causes some unfortunate defects, such as cracks and burnt cavities, which can impact the correct functionality of the machined pieces and shorten their service life. This study was carried out to understand which materials remain defect-free after WEDM. The examined materials were the Ampcoloy 35 copper alloy, the high-entropy steels FeCoCrMnNi and FeCoCrMnNiC0.2, and the B1914 and Nimonic 263 nickel alloys. The influence of the machining parameters, namely the pulse off time, gap voltage, discharge current, pulse on time, and wire feed, on the cutting speed and the surface topography of the machined piece was investigated. The surface morphology, the state of the subsurface layer in a cross-section, and the number of diffused elements from the wire electrode were analysed. All the analysed materials were found completely suitable for WEDM machining as they do not form any surface or subsurface defects.

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