A Controlled Hahn-Mazurkiewicz Theorem and its Applications

For a metric Peano continuum $X$, let $S_X$ be a Sierpi\'nski function assigning to each $\varepsilon>0$ the smallest cardinality of a cover of $X$ by connected subsets of diameter $\le \varepsilon$. We prove that for any increasing function $\Omega:\mathbb R_+\to\mathbb R_+$ with $(0,1]\subseteq\Omega[\mathbb R_+]$ and $s:=\sum_{n=1}^\infty S_X(2^{-n})\sum_{m=n}^\infty S_X(2^{-m})\,\Omega^{-1}(\min\{1,2^{6-m}\})<\infty$ there exists a continuous surjective function $f:[0,s]\to X$ with continuity modulus $\omega_f\le\Omega$. This controlled version of the classical Hahn-Mazurkiewicz Theorem implies that $SDim(X)\le HDim(X)\le 2{\cdot}SDim(X)$, where $SDim(X)=\limsup_{\varepsilon\to 0}\frac{\ln(S_X(\varepsilon))}{\ln(1/\varepsilon)}$ is the $S$-dimension of $X$, and $HDim(X)=\inf\{\alpha\in (0,\infty]:$ there is a~surjective $\frac1\alpha$-H\"older map $f:[0,1]\to X\}$ is the $H\ddot older$ $dimension$ of $X$.Comment: 17 page

The Analysis of the Residual Stress Evolution during Cycling Oxidation of the Ni-base Superalloys at High Temperature

The lifetime of the elements made of Ni-base superalloys can be strongly increased by introducing compressive stresses. Such stresses increase the resistance of cracks nucleation and formation during cyclic loads. Therefore, it is important to know how the stresses in the cold rolled Ni-based superalloys evolve during the service. Ni-base superalloys are dedicated to the usage at elevated temperature. However, exposing the Ni-based superalloys to high temperature results in their oxidation. So far, not a single work on the studies of the residual stress evolution in the Ni-based superalloys during cycling oxidation at high temperature was performed. Thus in the present study the residual stress in the materials in the as-received conditions and the changes in the residual stresses during cycling oxidation of IN 625 and IN 718 at 1273 K in air was investigated and described. The obtained results showed differences in the residual stresses level measured for investigated alloys. It was also found that thermal cycling of studied alloys influences the residual stresses. However even after the end of the test, the measured residual stresses were still compressive. Slightly different oxidation resistance was found for the studied alloys, namely, IN 718 was found to be more prone to oxide scale spallation. The latter was correlated with different alloy chemical composition, which results in formation of δ - phase in IN 718. The dissolution of δ - phase during high temperature exposure resulted in formation of sub-scale enriched with Nb and Ti in the near oxide scale/substrate interface. The latter was claimed to have a negative effect on oxide scale adherence

Contractive function systems, their attractors and metrization

In this paper we study the Hutchinson-Barnsley theory of fractals in the setting of multimetric spaces (which are sets endowed with point separating families of pseudometrics) and in the setting of topological spaces. We find natural connections between these two approaches

In Sync: Exploring Synchronization to Increase Trust Between Humans and Non-humanoid Robots

When we go for a walk with friends, we can observe an interesting effect: From step lengths to arm movements - our movements unconsciously align; they synchronize. Prior research found that this synchronization is a crucial aspect of human relations that strengthens social cohesion and trust. Generalizing from these findings in synchronization theory, we propose a dynamical approach that can be applied in the design of non-humanoid robots to increase trust. We contribute the results of a controlled experiment with 51 participants exploring our concept in a between-subjects design. For this, we built a prototype of a simple non-humanoid robot that can bend to follow human movements and vary the movement synchronization patterns. We found that synchronized movements lead to significantly higher ratings in an established questionnaire on trust between people and automation but did not influence the willingness to spend money in a trust game.Comment: To appear in Proceedings of the 2023 CHI Conference on Human Factors in Computing Systems (CHI 23), April 23-28, 2023, Hamburg, Germany. ACM, New York, NY, USA, 14 page

Immunomodulatory antibodies in cancer therapy

Jedną z grup leków immunomodulacyjnych, modyfikujących działanie układu odpornościowego, są przeciwciała monoklonalne. Negatywne receptory, takie jak CTLA-4 i PD-1, obniżają poziom stymulacji komórki, a w opisywanych przypadkach — hamują aktywację i proliferację limfocytów T. Fizjologiczną funkcją tych receptorów jest eliminacja autoreaktywnych komórek odpornościowych, które nie zostały zniszczone w mechanizmie tolerancji centralnej, oraz ochrona tkanek organizmu zmienionych zapalnie. Nowotwory, poprzez ekspresję ligandów dla negatywnych receptorów, unikają rozpoznania przez układ immunologiczny. Działanie przeciwciał obejmuje blokowanie receptorów CTLA-4 i PD-1, przywracając limfocytom zdolność rozpoznawania i reagowania na antygeny nowotworowe. Dotychczasowe badania przeprowadzone nad lekami anty-CTLA, anty-PD-1 i anty-PD-L1 wykazują umiarkowaną skuteczność w leczeniu niektórych zaawansowanych nowotworów, często opornych na leczenie standardowe, połączoną z trwałą remisją guza. Szczególnie korzystne okazało się łączenie dwóch grup leków z efektem synergistycznym. Pomimo zachęcających wyników dotychczasowych badań wciąż przed naukowcami stoją wyzwania, takie jak znalezienie obiektywnych markerów szacujących korzyści leczenia danego pacjenta, zmniejszenie liczby działań niepożądanych oraz normalizacja cen nowych leków.Among the immunomodulatory drugs modifying the immune system are monoclonal antibodies. Negative recep­tors, such as Cytotoxic T Cell Antigen 4 (CTLA-4) and Programmed Cell Death protein 1 (PD-1), reduce the level of cell stimulation by other receptors in the cases described. They inhibit the activation and proliferation of T cells. The physiological function of these receptors is the elimination of autoreactive immune cells, which have not been destroyed in the mechanism of central tolerance, and the protection of inflamed tissues in the body. Tumours by expressing negative receptor ligands avoid recognition by the immune system. Antibodies action involves blocking CTLA-4 and PD-1 receptors, restoring the ability of lymphocytes to recognise and respond to tumour antigens. Previous studies of anti-CTLA, anti-PD-1 and anti-PD-L1 drugs are moderately effective in the treatment of some advanced cancers with durable remission of the tumour. It has been proved that it is particularly advantageous to combine the two agents in synergistic effect. Despite the encouraging results of previous studies, it is necessary to find objective markers for estimating the benefits of treatment, to reduce the amount of side effects and normalise the prices of new drugs

Study on the impact of the use of no-code application on internal logistics processes in a company from the e-commerce industry : process analysis

PURPOSE: The article aims to deliver the possible methodology of implementing no-code applications, and its possible impact on internal processes with an example from a company in the e-commerce industry, these processes.DESIGN/METHODOLOGY/APPROACH: The study was conducted in a logistics company responsible for comprehensive shipment service. The basic research method was a process study aimed at diagnosing problems occurring at various stages of shipment handling, with a particular focus on the process of parcels acceptance in the warehouse. The results of the study were used for a deeper analysis of individual phases of this process and helped to identify areas for improvement. The last stage of the study was to develop a mobile application solution, with the usage of the no-code platform, which could improve the effectiveness of the analyzed process.FINDINGS: The conducted analysis showed that implementing a simple mobile application and designing a new process which uses it, may contribute not only to reduction of the time spent in the process of parcels acceptance in the warehouse but it also helps to totally reduce the number of paper documents generated in this process.ORIGINALITY/VALUE: The carried out research shows that, creating mobile applications using no-code platforms seems to be justified for processes improvement. The implementation of such solutions allows for a relatively quick increase in efficiency or the elimination of current limitations in processes that are crucial for the company. Furthermore, the study shows that the implementation of improvements using no-code application is relatively effective in relation to the time and costs necessary to carry it out.peer-reviewe

PSDRS, BDI, MoCA and MMSE as screening tools for the evaluation of mood and cognitive functions in patients at the early stage of cerebral stroke

Aims. To evaluate the suitability of the Post-Stroke Depression Scale (PSDRS) for detecting affective disorders, to examine the correlation of depressed mood states with cognitive disorders in patients at an early stage of cerebral stroke, and to attempt a comparison of the effectiveness of detecting depressive and cognitive disorders with the selected clinical scales. Material and methods. The examination involved 43 patients within the first week after cerebral stroke. It was carried out with the application of two screening scales, the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA), and two scales for the evaluation of the degree of depressiveness: PSDRS and Beck Depression Inventory (BDI). Results. A significant negative correlation of the results of the PSDRS and MoCA scales was shown. Depressed mood in patients post-cerebral stroke was statistically significantly correlated with the disorders in selected cognitive skills: visual and spatial functions, memory, attention functions and abstracting ability. Conclusions. The PSDRS and MoCA scales proved to be more effective tools for the evaluation of depressive and cognitive disorders in patients at an early stage after cerebral stroke than the conventionally applied MMSE and BDI scales. The examination results additionally show a significant dependence between mood and the cognitive impairment in this group of patients. With the weakening of cognitive functioning, the patients’ mood also became depressed

Virtual Modelling and Simulation of a CNC Machine Feed Drive System

This paper deals with the virtual modelling and simulation of a complex CNC machine tool feed drive system. The first phase of the study was the modelling of a very complex structure of the feed drive which consists of many elements (position, velocity and current control regulators, actuators, mechanical transmission elements, etc.). All these elements have great influence on important parameters of the machine tool such as movement stability, positioning accuracy and dynamic stiffness. For the modelling of the system the Matlab-SIMULINK and Matlab-Sim Scape Toolbox software was used. The Matlab-Sim Scape Toolbox allowed us to use the complete CAD model of the geometry of the machine tool, automatically calculating the selected properties. The influence of changing and optimizing several feed drive parameters (position loop gain Kv, proportional gain Kp of the velocity controller, integral gain of velocity controller-Tn, electrical drive time constant Te, total moving mass m, sampling period Ts, etc.) on the positioning accuracy and the dynamic stiffness was simulated, tested and validated. The finished Matlab-Simulink and Sim Scape models were initially visualized in the Matlab program. They were very simplified, comparing with their later visualization in the Virtual Reality EON Studio program