On values of repeated games with signals

We study the existence of different notions of value in two-person zero-sum repeated games where the state evolves and players receive signals. We provide some examples showing that the limsup value (and the uniform value) may not exist in general. Then we show the existence of the value for any Borel payoff function if the players observe a public signal including the actions played. We also prove two other positive results without assumptions on the signaling structure: the existence of the $\sup$ value in any game and the existence of the uniform value in recursive games with nonnegative payoffs.Comment: Published at http://dx.doi.org/10.1214/14-AAP1095 in the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

Blackwell-Optimal Strategies in Priority Mean-Payoff Games

We examine perfect information stochastic mean-payoff games - a class of games containing as special sub-classes the usual mean-payoff games and parity games. We show that deterministic memoryless strategies that are optimal for discounted games with state-dependent discount factors close to 1 are optimal for priority mean-payoff games establishing a strong link between these two classes

Limits of multi-discounted Markov decision processes

Markov decision processes (MDPs) are controllable discrete event systems with stochastic transitions. The payoff received by the controller can be evaluated in different ways, depending on the payoff function the MDP is equipped with. For example a mean–payoff function evaluates average performance, whereas a discounted payoff function gives more weights to earlier performance by means of a discount factor. Another well–known example is the parity payoff function which is used to encode logical specifications [14]. Surprisingly, parity and mean–payoff MDPs share two non–trivial properties: they both have pure stationary optimal strategies [4, 15] and they both are approximable by discounted MDPs with multiple discount factors (multi– discounted MDPs) [5, 15]. In this paper we unify and generalize these results. We introduce a new class of payoff functions called the priority weighted payoff functions, which are generalization of both parity and mean–payoff functions. We prove that priority weighted MDPs admit optimal strategies that are pure and stationary, and that the priority weighted value of an MDP is the limit of the multi–discounted value when discount factors tend to 0 simultaneously at various speeds. 1

Local Computations in Graphs: The Case of Cellular Edge Local Computations

We examine the power and limitations of the weakest vertex relabelling system which allows to change a label of a vertex in function of its own label and of the label of one of its neighbours. We characterize the graphs for which two important distributed algorithmic problems are solvable in this model: naming and election

Acquaintance of bases of the prevention of the testicular cancer amongst the chosen group of men

Wstęp: Profilaktyka pierwszego rzędu, szeroko zakrojona i odpowiednio realizowana, może w znaczący sposób zmienić obecne niekorzystne tendencje w zakresie wczesnego rozpoznawania raka jądra. Cel pracy: Celem pracy jest ocena znajomości podstawowych zasad profilaktyki raka jądra u badanych mężczyzn oraz ich zainteresowania programami profilaktycznymi z tego zakresu. Materiał i metody: Badania przeprowadzono wśród 150 mężczyzn, mieszkańców gminy Międzyrzecz, z wykorzystaniem metody sondażu diagnostycznego opartego na technice ankiety, do której sporządzono autorski kwestionariusz. Wyniki: Mężczyźni w większości nie wykonują samobadania jąder (58% badanych – 87 osób) bądź robią to niesystematycznie (34% – 51 osób), choć nie z powodu skrępowania (56% badanych – 84 osoby). Wizyty u urologa uznają za konieczne, choć większość (68% – 102 osoby) dotychczas z nich nie korzystała. Potwierdzają również konieczność szerszej edukacji w zakresie chorób męskich narządów płciowych, choć nigdy nie brali udziału w programach profilaktycznych dotyczących tej tematyki. Wnioski: Konieczne jest położenie większego nacisku na działania profilaktyczne, kierowane zarówno do pojedynczych mężczyzn, jak i do całej męskiej populacji.Background: The first order prophylaxis, which is comprehensive and well organised, is able to change significantly the unfavourable tendencies in the early testicular cancer recognition. Aim of the study: The study aims at the evaluation of the knowledge of fundamental preventive measures regarding testicular cancer in men and their interest in prophylactic programmes. Material and methods: The research was carried out among 150 male residents of Międzyrzecz. The method included the diagnostic survey in the form of a questionnaire prepared by the author. Results: Most of the men, examined in the study, do not perform the self-examination of the testicles (58% – 87 examinees), or perform it unsystematically (34% – 51 examinees). However, as the results show, they do not feel embarrassed at the procedure (56% – 84 examinees). They consider regular visits to a urologist as necessary, although, the majority of them have never done it (68% – 102 examinees). They also confirm the need for wider education about the illnesses of the male reproductive organs, although, they have never participated in any preventive programs considering the issue themselves. Conclusions: There is a strong necessity for greater prophylaxis of testicular cancer, directed both to every singular man and the entire male population

Hemp-Based Phytoaccumulation of Heavy Metals from Municipal Sewage Sludge and Phosphogypsum Under Field Conditions

The aim of this study was to evaluate the ability of three hemp cultivars to accumulate heavy metals under sewage sludge (SS) and phosphogypsum (PG) application. The field study was carried out from 2014 to 2016 on Luvisol (loamy sand) in Poland. The experiment scheme included five treatments—T0: the control without fertilization, T1: 170 kg N (nitrogen) ha−1 from sewage sludge, T2: 170 kg N ha−1 from sewage sludge and 100 kg ha−1 of phosphogypsum, T3: 170 kg N ha−1 from sewage sludge and 500 kg ha−1 of phosphogypsum, and T4: 170 kg N ha−1 from sewage sludge and 1000 kg ha−1 of phosphogypsum. It was found that the application of municipal sewage sludge enriched the soil with the bioavailable forms of heavy metals to the greatest extent and contributed to the highest increase in their contents in vegetative and generative organs of hemp plants. These parameters showed a phosphogypsum dose-dependent decline, which could hinder the phytoextraction process. The greatest extractions of heavy metal(loid)s (HMs) from the soil treated with SS and PG were achieved by the Tygra variety, which had the highest bioconcentration factor (BCF) and biomass yield