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542. A backward selection procedure for approximating a discrete probability distribution by decomposable models
- Creator:
- Malvestuto, Francesco M.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- backward selection, information divergence, decomposable model, acyclic hypergraph, and k-hypertree
- Language:
- English
- Description:
- Decomposable (probabilistic) models are log-linear models generated by acyclic hypergraphs, and a number of nice properties enjoyed by them are known. In many applications the following selection problem naturally arises: given a probability distribution p over a finite set V of n discrete variables and a positive integer k, find a decomposable model with tree-width k that best fits p. If H is the generating hypergraph of a decomposable model and pH is the estimate of p under the model, we can measure the closeness of pH to p by the information divergence D(p:pH), so that the problem above reads: given p and k, find an acyclic, connected hypergraph H of tree-width k such that D(p:pH) is minimum. It is well-known that this problem is NP-hard. However, for k=1 it was solved by Chow and Liu in a very efficient way; thus, starting from an optimal Chow-Liu solution, a few forward-selection procedures have been proposed with the aim at finding a `good' solution for an arbitrary k. We propose a backward-selection procedure which starts from the (trivial) optimal solution for k=n−1, and we show that, in a study case taken from literature, our procedure succeeds in finding an optimal solution for every k. .
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
543. A barrier method for quasilinear ordinary differential equations of the curvature type
- Creator:
- Kusahara, Toshiaki and Usami, Hiroyuki
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- math and barrier methods
- Language:
- English
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
544. A belated education
- Creator:
- Hall, John A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
545. A bi-average tree solution for probabilistic communication situations with fuzzy coalition
- Creator:
- Li, Xianghui , Sun , Hao , and Hou, Dongshuang
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- fuzzy coalition, probabilistic communication situation, average tree solution, and maximal product spanning tree
- Language:
- English
- Description:
- A probabilistic communication structure considers the setting with communication restrictions in which each pair of players has a probability to communicate directly. In this paper, we consider a more general framework, called a probabilistic communication structure with fuzzy coalition, that allows any player to have a participation degree to cooperate within a coalition. A maximal product spanning tree, indicating a way of the greatest possibility to communicate among the players, is introduced where the unique path from one player to another is optimal. We present a feasible procedure to find the maximal product spanning trees. Furthermore, for games under this model, a new solution concept in terms of the average tree solution is proposed and axiomatized by defining a restricted game in Choquet integral form.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
546. A bibliometric analysis of research papers published on photosynthesis: 1992-2009
- Creator:
- Yu, J. J., Wang, M. H., Xu, M., and Ho, Y. S.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- bibliometrie, bibliometrics, author keyword, research trend, scientometrics, science citation index expanded, 12, and 00
- Language:
- Multiple languages
- Description:
- We present here a bibliometric analysis of publications on photosynthesis research from 1992 to 2009 in the Science Citation Index Expanded (SCI-Expanded) Web of Science. This has allowed us to examine the growing trends and the key topics on this subject. We have assessed the document type, language of the publications, publication output, subject category, journal distribution, countries and territories of these publications, institutions involved, hot topics and highly cited papers. The top 30 countries/territories were ranked according to their total number of articles (TA), single country articles (SCA), internationally collaborative articles (ICA), first author articles (FAA) and corresponding author articles (CAA). Research directions on the subject of photosynthesis were also investigated and evaluated by statistically analyzing the distribution of author keywords in the database. Our analysis indicates that “water”, “stress”, “carbon dioxide”, “nitrogen” and “climate change” are hot topics of research on photosynthesis during this period., J. J. Yu ... [et al.]., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
547. A binary operation-based representation of a lattice
- Creator:
- Yettou, Mourad , Amroune, Abdelaziz , and Zedam, Lemnaouar
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- binary operation, lattice, neutral element, and lattice representation
- Language:
- English
- Description:
- In this paper, we study and characterize some properties of a given binary operation on a lattice. More specifically, we show necessary and sufficient conditions under which a binary operation on a lattice coincides with its meet (resp. its join) operation. Importantly, we construct two new posets based on a given binary operation on a lattice and investigate some cases that these two posets have a lattice structure. Moreover, we provide some representations of a given lattice based on these new constructed lattices.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
548. A biologically inspired neural model of vision-language integration
- Creator:
- Plebe, Alessio, Mazzone , Marco, and De La Cruz , Vivian M.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Categorization, self-organization, visual cortex, and population coding
- Language:
- English
- Description:
- One crucial step in the construction of the human representation of the world is found at the boundary between two basic stimuli: visual experience and the sounds of language. In the developmental stage when the ability of recognizing objects consolidates, and that of segmenting streams of sounds into familiar chunks emerges, the mind gradually grasps the idea that utterances are related to the visible entities of the world. The model presented here is an attempt to reproduce this process, in its basic form, simulating the visual and auditory pathways, and a portion of the prefrontal cortex putatively responsible for more abstract representations of object classes. Simulations have been performed with the model, using a set of images of 100 real world objects seen from many different viewpoints and waveforms of labels of various classes of objects. Subsequently, categorization processes with and without language are also compared.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
549. A blood pact: the significance and implications of eIF4E on lymphocytic leukemia
- Creator:
- Venturi, V, Masek, T., and Martin Pospíšek
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- leukémie, leukemia, eukaryotic initiation factor 4E, eIF4E, lymphocytic leukemia, translation initiation, protein synthesis, hematological diseases, ALL, CLL, 14, and 612
- Language:
- English
- Description:
- Elevated levels of eukaryotic initiation factor 4E (eIF4E) are implicated in neoplasia, with cumulative evidence pointing to its role in the etiopathogenesis of hematological diseases. As a node of convergence for several oncogenic signaling pathways, eIF4E has attracted a great deal of interest from biologists and clinicians whose efforts have been targeting this translation factor and its biological circuits in the battle against leukemia. The role of eIF4E in myeloid leukemia has been ascertained and drugs targeting its functions have found their place in clinical trials. Little is known, however, about the pertinence of eIF4E to the biology of lymphocytic leukemia and a paucity of literature is available in this regard that prospectively evaluates the topic to guide practice in hematological cancer. A comprehensive analysis on the significance of eIF4E translation factor in the clinical picture of leukemia arises, therefore, as a compelling need. This review presents aspects of eIF4E involvement in the realm of the lymphoblastic leukemia status; translational control of immunological function via eIF4E and the state-of-the-art in drugs will also be outlined., V. Venturi, T. Masek, M. Pospisek., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
550. A Borel extension approach to weakly compact operators on $C_0(T)$.
- Creator:
- Panchapagesan, Thiruvaiyaru V.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- math and Borel extension theorem
- Language:
- English
- Description:
- Let $X$ be a quasicomplete locally convex Hausdorff space. Let $T$ be a locally compact Hausdorff space and let $C_0(T) = \lbrace f\: T \rightarrow I$, $f$ is continuous and vanishes at infinity$\rbrace $ be endowed with the supremum norm. Starting with the Borel extension theorem for $X$-valued $\sigma $-additive Baire measures on $T$, an alternative proof is given to obtain all the characterizations given in [13] for a continuous linear map $u\: C_0(T) \rightarrow X$ to be weakly compact.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public