Efficient Simulations of Large Scale Convective Heat Transfer Problems

We describe an approach for efficient solution of large scale convective heat transfer problems, formulated as coupled unsteady heat conduction and incompressible fluid flow equations. The original problem is discretized in time using classical implicit methods, while stabilized finite elements are used for space discretization. The algorithm employed for the discretization of the fluid flow problem uses Picard's iterations to solve the arising nonlinear equations. Both problems, heat transfer and Navier-Stokes quations, give rise to large sparse systems of linear equations. The systems are solved using iterative GMRES solver with suitable preconditioning. For the incompressible flow equations we employ a special preconditioner based on algebraic multigrid (AMG) technique. The paper presents algorithmic and implementation details of the solution procedure, which is suitably tuned, especially for ill conditioned systems arising from discretizations of incompressible Navier-Stokes equations. We describe parallel implementation of the solver using MPI and elements of PETSC library. The scalability of the solver is favourably compared with other methods such as direct solvers and standard GMRES method with ILU preconditioning.

X-ray absorption near edge structure and Mössbauer spectroscopy in study of iron valence states in tissues

X-ray absorption near edge structure Fe K-edge spectra and $\text{}^{57}$Fe Mössbauer spectra of selected standard compounds were recorded at room temperature. Valence and spin states of Fe in these samples known from Mössbauer spectroscopy were correlated with the shapes of X-ray absorption near edge structure spectra in search of possible application of X-ray absorption near edge structure spectroscopy as analytical tool determining local electronic states of iron in tissues. As an example, the X-ray absorption near edge structure spectra of healthy and cancerous tissues of prostate are shown, suggesting Fe$\text{}^{3+}$ in cancerous tissues

Effectiveness of mesh hernioplasty in incarcerated inguinal hernias

INTRODUCTION: The use of mesh is still controversial in patients undergoing emergency incarcerated hernia repair, mostly because of potential infectious complications. AIM: The main aim of this study was to assess the efficacy of tension-free methods in treating incarcerated inguinal hernias (IIH), with and without intestine resection. The secondary aim was to establish an algorithm on how to proceed with incarcerated hernias. MATERIAL AND METHODS: A retrospective analysis of patients who underwent surgery due to an inguinal hernia at the First Department of General Surgery Jagiellonian University Medical College in Krakow, in the period 1999–2009. Operative methods included Lichtenstein, Robbins-Rutkow and Prolene Hernia System. The rate of postoperative complications was compared in patients who underwent elective and emergency surgery. RESULTS: The study group consisted of 567 patients (546 male) age 19–91 years. In this group 624 hernias were treated using the three tension-free techniques – 295 using the Lichtenstein method, 236 using PHS and 93 using the RR technique. Out of the 561 operations 89.9% were elective. No correlation (p > 0.05) was found between the type of surgery and such complications as postoperative pain duration and intensity, fever, micturation disorders, wound healing disorders, testicle hydrocoele, testicle atrophy, spermatic cord cyst, sexual dysfunction, wound dehiscence, wound suppuration, seroma, haematoma and hernia recurrence. CONCLUSIONS: Mesh repairs can be safely performed while operating due to an IIH. The use of a synthetic implant, in emergency IIH repairs, does not increase the rate of local complications. Synchronous, partial resection of the small intestine, due to intestinal necrosis, is not a contraindication to use mesh

The Liability of Online Content Sharing Service Providers – Comparative Analysis of the European Union and the US Copyright Laws

Przedmiotem pracy jest analiza prawnoautorskiej odpowiedzialności dostawców usług udostępniania treści online w kontekście europejskiego oraz amerykańskiego systemu prawnego. Praca składa się z pięciu merytorycznych części. W pierwszej części dokonano przeglądu źródeł prawa regulujących odpowiedzialność dostawców usług udostępniania treści online w Unii Europejskiej oraz Stanach Zjednoczonych Ameryki. Analizę źródeł prawa rozpoczęto od zarysowania tła historycznego prac legislacyjnych, a następnie przywołano najbardziej istotne postanowienia Dyreketywy2000/31, Dyrektywy 2001/29 oraz Dyrektywy 2019/790 oraz Amerykańskiego Telecommunications Act 1996 i Data Millennium Copyright Act 1998. W części drugiej wyjaśniono pojęcie dostawcy usług udostepnienia treści online w kontekście dotychczas obowiązujących przepisów na gruncie prawa unijnego oraz amerykańskiego. W kolejnych częściach opisano zasady odpowiedzialności dostawców usług udostępniania treści online w kontekście reżimu „notice and take down” jak również w aspekcie nowego reżimu ukształtowanego na gruncie Dyrektywy 2019/790. W odniesieniu do obu reżimów odpowiedzialności skatalogowano przesłanki wyłączenia odpowiedzialności dostawców usług, a także dokonano analizy skuteczności poszczególnych rozwiązań prawnych. W ostatniej części podjęto próbę dokonania autorskiej analizy skutków jakie może przynieść implementacja Dyrektywy 2019/790 w kontekście funkcjonowania dostawców usług oraz konsekwencji jakie może to przynieść dla użytkowników oraz podmiotów uprawnionych. Przedmiotowa praca sygnalizuje obszary prawa z zakresu przedmiotowej tematyki, w których widoczne jest niedostoswanie obowiązujących lub proponowanych przepisów prawa w perspektywie zmian gospodarczych, społecznych i kulturowych.The subject matter of this study is the liability of online content sharing service providers in the context of European Union and the US Laws. The work is divided into five substantive parts. In the first part, the author presents the sources of law applicable to liability of online content sharing service providers in the US and the EU. In the second part the author provides the characteristic of definition of online content sharing service providers in the context of the former binding laws of the EU as well as current applicable laws of the US and EU. Next chapters include analysis of liability rules of online content sharing service providers in the context of the "notice and take down" regime as well as in the aspect of the new regime shaped under Directive 2019/790. In the final part, the author conducts its own analysis of the potential consequences of implementation of Directive 2019/790. The purpose of the study is not only to present the currently binding legal solution of the issue but also to identify the areas of the law that should be changed in order to stimulate creativity and improve freedom of expression on Internet

The author’s economic rights as a subject of the non-pecuniary contribution to a limited company

Przedmiotem pracy jest analiza autorskich praw majątkowych jako przedmiotu wkładu niepieniężnego do spółek kapitałowych. Praca składa się z czterech merytorycznych części. W pierwszej części poruszono te kwestie z zakresu prawa autorskiego, które są istotne w perspektywie aportu autorskich praw majątkowych do spółek kapitałowych. Analizie poddano zatem kwestię powstania praw autorskich, ustalenia podmiotów uprawnionych do dysponowania prawymi autorskimi, problematykę zbywalności praw autorskich i określenia ich pól eksploatacji, a także relacje praw autorskich majątkowych wobec praw osobistych. W kolejnych częściach pracy omówiono najważniejsze zagadnienia związane z wkładem niepieniężnym do spółek z ograniczoną odpowiedzialnością jak i spółek akcyjnych. Nakreślono problematykę wyceny autorskich praw majątkowych oraz odpowiedzialności wspólnika bądź akcjonariusza za przeszacowanie lub niedoszacowanie wartości wkładu. Wskazano metodologię przyjmowaną do określenia wartości autorskich praw majątkowych oraz autorski katalog czynników mających wpływ na cenę tychże praw. Analizie poddano również kwestię odpowiedzialności za wady prawne wkładu niepieniężnego oraz odpowiedzialności za brak bądź nieterminowe wniesienie wkładu niepieniężnego. Zaprezentowano również autorski katalog obszarów w których mogą pojawić się wady prawne autorskich praw majątkowych. Przedmiotowa praca sygnalizuje obszary prawa z zakresu przedmiotowej tematyki, w których widoczne jest niedostoswanie obowiązujących przepisów prawa w perspektywie zmian gospodarczych, społecznych i kulturowych.The subject matter of this study is an issue of author’s economic rights as an non-pecuniary contribution to a limited company. The work is divided into four substantive parts. In the first part, the author presents the key concerns that may arise in the context of transfers of author’s economic rights. Next chapter includes the characteristics of those aspects of corporate law that specifically regulates the issue of the non-pecuniary contribution to limited companies. In the final part, the author examines the methods of copyrights valuation and the liability of the stockholder or the stakeholders for increasing or decreasing the value of the object contribution to the company. The purpose of the study is not only to present the currently binding legal solution of the issue but also to identify the areas of the Polish law that should be changed in order to improve the economic exploitation of copyrights

The Dynamics of Beech Roundwood Prices in Selected Central European Markets

The European beech (Fagus sylvatica L.) is the most prevalent deciduous tree species in Central Europe. The implementation of sustainable, close-to-nature silvicultural practices increased the percentage share of beech in forest species composition, raising the economic significance of beech roundwood, especially in terms of revenues from timber sales. The elucidation of roundwood price mechanisms as well as long-term equilibrium relations between international markets may be helpful in calculating the profitability of beech roundwood production. The study material consists of quarterly time series of beech roundwood prices from Austria, Czechia, Germany, Poland, Slovakia, and Slovenia in the years 2005–2018. The price time series were described with a multiplicative model incorporating seasonal, cyclical, and irregular, as well as long-term trend components. The time series were decomposed using the Census X11 method. Stationarity was tested by means of the augmented Dickey–Fuller test (ADF) and the Kwiatkowski–Phillips–Schmidt–Shin test (KPSS). Cointegration was assessed using the Johansen and Engle–Granger methods. From 2005–2018, the highest mean beech roundwood prices were found for Austria (77.5 € m−3) and Germany, and the lowest for Poland and Slovakia. Roundwood prices were badly affected by the 2008/2009 financial crisis, which caused an approx. 27% decline. The prices of large-diameter beech logs exhibited seasonal fluctuations, typically reaching a maximum in Q1 and a minimum in Q3. The amplitude of those fluctuations was the highest in Slovenia in 2005 (10.1%), while in Czechia and Germany, seasonal effects increased over the period of study. The lowest seasonality was found in Slovakia and Austria (in the latter country it was not statistically significant). On an annual scale, cyclical changes generally accounted for the largest proportion of price variation, and were particularly pronounced in Poland (78.9%), Slovakia (78.6%), and Austria (69.2%). On the other hand, seasonal effects were predominant in the Slovenian (40.6%), German (34.1%), and Czech (33.3%) markets. In countries with price series of type I(0), simple correlation between stationary beech roundwood prices is positive and the strongest between Czechia–Poland and Czechia–Austria; on the other hand they are the weakest in the German market. In Slovakia and Slovenia with nonstationary price series, both Johansen’s and Engle-Granger’s cointegration tests indicated the absence of a long-term equilibrium between the analyzed beech timber markets. Results revealed integration between the prices of large-diameter beech logs in Czechia, Austria, and Poland. It should be mentioned that in this study, the time series of price used are rather short for long time cointegration analysis, which might prevent the proper detection of cointegration between all analyzed countries

Assessing the Technical Efficiency of Timber Production during the Transition from a Production-Oriented Management Model to a Multifunctional One: A Case from Poland 1990–2019

The present work applied a data envelopment analysis (DEA) model to assess changes in the technical efficiency of timber production at a period of transition in forest management priorities. The study material consisted of data on timber sold by Polish State Forests (PSF) and on its forest management inputs in the years 1990–2019. During the period of economic transition in Poland (1990–2003) the technical efficiency of timber production on average amounted to 0.809 and was highly variable. In the free-market period, that efficiency was much higher (on average 0.939) and more stable. This improvement was achieved by substantial layoffs in the PSF, and steady rise in the share and standing volume of mature stands, which made it possible to increase timber production while adhering to sustainable management principles. Analysis of the various categories of inputs to timber production revealed that the greatest decline, in labor costs, was attributable to a fourfold reduction in the workforce, and was accompanied by a 2.4-fold increment in timber production. On the other hand, logging costs increased due to, among other causes, the pursuit of environmentally friendly but more expensive harvesting procedures and reductions in clearcutting, which entailed more dispersed harvesting operations

Eye-tracking research on solving mathematical text-based problems

Neurodydaktyka jest nową interdyscyplinarną dziedziną badawczą, zajmującą się mechanizmami procesu uczenia się i nauczania. O pracy naszego mózgu w czasie rozwiązywania zadań, problemów podanych w formie obrazu (zapisu słownego) świadczą między innymi ruchy oczu. Zapisem ruchu oczu zajmuje się między innymi eyetracking (okulografia). Tak jak możemy wyróżnić różne rodzaje inteligencji, tak też możemy wyróżnić różne style uczenia się. W związku z tym pojawia się pytanie, czy uczniowie – nauczani przez tego samego nauczyciela – będą stosowali jednakową kolejność wykonywania działań matematycznych, czy też będą wykorzystywali dane liczbowe przedstawione w zadaniu w kolejności, w jakiej występują one w tekście. Przeprowadzono badania na grupie trzydzieściorga uczniów piątej klas szkoły podstawowej. Przy pomocy specjalnie skonstruowanego do badań programu komputerowego, wykonując pomiary przy pomocy eyetrackera, monitorowano ruch oczu w czasie rozwiązywania prostego tekstowego zadania z matematyki. W wyniku badań stwierdzono, że nie można określić dominującego sposobu rozwiązywania przedstawianych zadań. Ten sam uczeń stosował inny sposób do rozwiązywania podobnych zadań.Neurodidactics is a new interdisciplinary research branch dealing with mechanisms of learning and teaching process. Activity of human brain during solving problems, exercises provided in the word-based form is reflected by, among others, movement of eyeballs. Recording of eye movements is, inter alia, conducted by eye tracking (oculography). Just like one can differentiate between various types of intelligence we are able to determine various learning styles. Thus a question arises whether students taught by the same teacher will apply the same sequence of doing mathematical operations or they will rather use figures presented in the task in the order they appear in the text. A research was conducted on a group of 30 students of the fifth grade of primary school. With the use of specially developed software for this study, taking measurements with the application of an eye tracker, eye movement was being monitored while solving a simple maths problem. As a result of the research, a predominant manner of solving basic problems cannot be determined. The same student applied different ways of solving similar tasks