This paper deals with a certain class of unbounded optimization problems. The optimization problems taken into account depend on a parameter. Firstly, there are established conditions which permit to guarantee the continuity with respect to the parameter of the minimum of the optimization problems under consideration, and the upper semicontinuity of the multifunction which applies each parameter into its set of minimizers. Besides, with the additional condition of uniqueness of the minimizer, its continuity is given. Some examples of nonconvex optimization problems that satisfy the conditions of the article are supplied. Secondly, the theory developed is applied to discounted Markov decision processes with unbounded cost functions and with possibly noncompact actions sets in order to obtain continuous optimal policies. This part of the paper is illustrated with two examples of the controlled Lindley's random walk. One of these examples has nonconstant action sets.
The hormone leptin, which is thought to be primarily produced by adipose tissue, is a polypeptide that was initially characterized by its ability to regulate food intake and energy metabolism. Leptin appears to signal the status of body energy stores to the brain, resulting in the regulation of food intake and whole-body energy expenditure. Subsequently, it was recognized as a cytokine with a wide range of peripheral actions and is involved in the regulation of a number of physiological systems including reproduction. In the fed state, leptin circulates in the plasma in proportion to body adiposity in all species studied to date. However other factors such as sex, age, body mass index (BMI), sex steroids and pregnancy may also affect leptin levels in plasma. In pregnant mice and humans, the placenta is also a major site of leptin expression. Leptin circulates in biological fluids both as free protein and in a form that is bound to the soluble isoform of its receptor or other binding proteins such as one of the immunoglobulin superfamily members Siglec-6 (OBBP1). Although the actions of leptin in the control of reproductive function are thought to be exerted mainly via the hypothalamicpituitary-gonadal axis, there have also been reports of local direct effects of leptin at the peripheral level, however, these data appear contradictory. Therefore, there is a need to summarize the current status of research outcomes and analyze the possible reasons for differing results and thus provide researchers with new insight in designing experiments to investigate leptin effect on reproduction. Most importantly, our recent experimental data suggesting that reproductive performance is improved by decreasing concentrations of peripheral leptin was unexpected and cannot be explained by hypotheses drawn from the experiments of excessive exogenous leptin administration to normal animals or ob/ob mice., M. Herrid, S. K. A. Palanisamy, U. A. Ciller, R. Fan, P. Moens, N. A. Smart, J. R. McFarlane., and Obsahuje bibliografii
Let $G=(V, E)$ be a simple graph. A subset $S\subseteq V$ is a dominating set of $G$, if for any vertex $u\in V-S$, there exists a vertex $v\in S$ such that $uv\in E$. The domination number, denoted by $\gamma (G)$, is the minimum cardinality of a dominating set. In this paper we will prove that if $G$ is a 5-regular graph, then $\gamma (G)\le {5\over 14}n$.
The basis number of a graph $G$ is defined by Schmeichel to be the least integer $h$ such that $G$ has an $h$-fold basis for its cycle space. MacLane showed that a graph is planar if and only if its basis number is $\le 2$. Schmeichel proved that the basis number of the complete graph $K_n$ is at most $3$. We generalize the result of Schmeichel by showing that the basis number of the $d$-th power of $K_n$ is at most $2d+1$.
The paper concerns mining data lacking the uniform structure. The
data are collected from a riumber of objects during repeated measurenients, all of which are tagged by a corresponding time. No attribute-valued machine learning algorithm can be applied directly on such data since the number of measurements is not fixed but it varies. The available data háve to be transformed and preprocessed in such a way that a uniform type of Information is obtained about all the considered objects. This can be achieved, e.g., by aggregation. But this process can introduce anachronistic variables, i.e., variables containing Information which cannot be available at the moment when a prediction is needed. The paper suggests and tests a method how to preprocess the considered type of data without falling into a trap of introducing anachronistic attributes. The method is illustrated on a čase study baaed on STULONG data.
This paper deals with the problem of semantic analysis of contexts involving so-called anaphoric chain. The notion of anaphoric chain is explained by way of an example. Afterwards, a semantic analysis of sentences containing anaphora established in Transparent Intensional Logic (TIL) is examined. It is demonstrated that it is not adequate for texts including anaphoric chains. An alternative method using TIL that is capable to deal with all kinds of anaphora is proposed. Anyway, one may raise doubts as to whether both approaches are really analyses of anaphorically used expressions., Článek se zabývá problematikou sémantické analýzy kontextů zahrnujících tzv. Anaforický řetězec . Pojem anaforický řetězec je vysvětlen na příkladu. Následně je zkoumána sémantická analýza vět obsahujících anaforu vytvořených v transparentní intenzivní logice (TIL). Je prokázáno, že není vhodný pro texty obsahující anaforické řetězce. Navrhuje se alternativní metoda používající TIL, která je schopna se vypořádat se všemi druhy anafor. V každém případě lze pochybovat, zda jsou oba přístupy skutečně analýzou anaforicky používaných výrazů., and Miloš Kosterec