Wielokryterialna optymalizacja trójwarstwowej paneli walcowej przy osiowym ściskaniu

The aim of this paper is to present the bicriteria optimization model of a sandwich cylindrical panel under axial compression. The objective functions are the weight and panel deformability. The deformability is defined as the panel bending rigidity reciprocal, and it represents some qualitative measure of the panel deflections. the design variables are the thicknesses of the layers. The constrains include a stability condition, stress conditions, the validation of theoretical models, and finally, technological and constructional requirements. The problem was solved with the help of Pareto's concept of optimality, with continuous and discrete sets of the design variables. Results of numerical calculations are presented in the form of tables and diagrams. A comparison of the optimal parameters for the unilayer and the sandwich panels is presented.W pracy sformułowano model dwukryterialnej optymalizacji cienkościennej trójwarstwowej paneli walcowej obciążonej osiowymi siłami ściskającymi. Kryteriami optymalizacyjnymi są masa paneli i jej podatność na odkształcenia. Podatność paneli, zdefiniowana jako odwrotność sztywności na zginanie, jest jakościową miarą odkszałcalności konstrukcji. Zmiennymi decyzyjnymi są grubości warstw paneli. Warunkami ograniczającymi są warunek stateczności, warunki wytrzymałościowe, warunek ważności stosowanych modeli teoretycznych oraz warunki technologiczno-konstrukcyjne. Zadanie rozwiązano w oparciu o koncepcję optimum Pareto, uwzględniając dyskretne i ciągłe zbiory zmiennych decyzyjnych. Wyniki obliczeń numerycznych przedstawione są w postaci tabel i wykresów. Porównano optymalne parametry paneli jedno- i trójwarstwowych

Interaktywne gry programu Vensim jako wsparcie procesu uczenia się w dynamice systemowej

This article presents the process of learning with the use of interactive gaming described on “Accidental Adversaries” archetype model, thus providing a new method of research than can be conducted on vast number of SD models. Authors selected an already well researched archetype to show a different approach in the process of model optimization. This gives the opportunity to share the knowledge about the possibilities of practical application of interactive gaming.W artykule opisano proces uczenia się z wykorzystaniem interaktywnych gier przedstawiony na archetypie „Przypadkowi przeciwnicy”, pokazując w ten sposób nową metodę badania, która może być zastosowana w ogromnej liczbie modeli dynamiki systemowej. Autorzy wybrali dokładnie zbadany i opisany w literaturze archetyp, aby zilustrować nowe podejście do procesu optymalizacji modelu. Przykład prezentuje nowe możliwości praktycznego zastosowania interaktywnych gier symulacyjnych

Tumor necrosis factor-alpha and Fas/Fas ligand signaling pathways in chronic spontaneous urticaria

Abstract Background There is increasing evidence pointing to the important role of tumor necrosis factor-alpha (TNF-α), a key inflammatory and apoptotic mediator in urticarial inflammation. However, the role of the TNF-α system and Fas/Fas ligand (FasL) in the apoptosis-inducing pathways in chronic spontaneous urticaria (CSU), remain unclear. Aim To determine circulating concentrations of TNF-α, soluble TNF-α receptor type 1 and type 2 (sTNF-R1 and sTNF-R2, respectively) as well as soluble Fas (sFas) and FasL (sFasL) in CSU subjects. Methods Serum TNF-α, sTNF-R1, sTNF-R2, sFas, sFasL concentrations were measured using enzyme-linked immunosorbent assay in CSU subjects and in the healthy subjects. Results TNF-α concentrations were significantly higher in CSU subjects and moderate-to-severe CSU than in the controls, while there were no significant differences in TNF-α concentrations between subjects with mild CSU and the controls. sTNF-R1 and sTNF-R2 concentrations were significantly higher in all CSU and moderate-severe CSU subjects vs. the controls. Serum concentrations were also significantly higher in mild CSU vs. the controls, but not in moderate-severe CSU vs. mild CSU. No significant differences were observed in sFas and sFasL concentrations between CSU subjects and the healthy controls. Significant correlations were found between concentrations of TNF-α and its receptors, as well as sTNF-R1 and sTNF-R2, but not with the urticaria activity score (UAS). There was no relationship between TNF-α/sTNF-R1/sTNF-R2 and sFas/sFasL pathways in CSU. Conclusions CSU is associated with the activation of the TNF-α/receptors signaling pathway, marked by increased circulating concentrations of TNF-α, sTNF-R1 and sTNF-R2, which are related to each other in this disease. In contrast, the circulating sFas/FasL system is not up-regulated in CSU, and sFas/sFasL may not be a useful marker of the activity/severity of urticarial processes. Considering the lack of significant changes in sFas/sFasL (mainly reflecting systemic apoptosis) in CSU patients, it appears that elevated serum TNF-α concentrations are related to its pro-inflammatory function rather than an enhanced systemic apoptotic response in CSU

Some simulation and optimization experiments on prey-predator model

The paper is an extension of the authors Kasperska E., Kasperski A., Bajon T. and Marjasz R. work (Kasperska et al., 2015) in the area of modeling and simulation of ecosystems on the base of "prey-predator" system dynamics model (presented on DSTA conference in 2015). The problem of connecting simulation with optimization is specially expanded to include both types of optimization - the policy optimization and the calibration. This new policy uses different set of parameters, model criteria and set of optimized parameters. The comparison between sensitivity analysis, optimization results and gaming outcome gives us a new view of learning process used by decision makers, model builders and students. We use the possibilities of visualization of simulation that are given by simulation language Vensim, and we try to apply calibration to detect the conditions, that stabilized that ecosystem and, what is quite new in the literature of this old, build the simulation game on base of that model to examine different scenarios of the human intervention in that ecosystem. At the end some conclusions are formulated

Interplay between acute phase response and coagulation/fibrinolysis in chronic spontaneous urticaria

Abstract Background Chronic spontaneous urticaria (CSU) is associated with activation of systemic inflammatory response and coagulation/fibrinolysis. Aim To study whether there is a relationship between the acute phase response and coagulation/fibrinolysis in chronic spontaneous urticaria (CSU) patients. Methods Serum concentrations of C-reactive protein (CRP) and interleukin 6 (IL-6), key markers of acute phase response and of D-dimer, a marker of fibrin turnover were investigated in 58 CSU patients assessed with the urticaria activity score (UAS) and the controls. Results Serum concentrations of IL-6, CRP, and D-dimer were significantly higher in CSU patients as compared with the controls. We found statistically significant correlations between D-dimers concentrations and the inflammatory markers: CRP and IL-6 as well as UAS. Conclusions Markers of inflammation (IL-6 and CRP) and of fibrinolysis (D-dimer) are related to each other in CSU, suggesting a possible cross-talk between inflammation and coagulation/fibrinolysis. It might be implicated in pathogenesis of the disease and may be associated with higher risks of cardiovascular diseases in CSU patients