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1092. A topological duality for the F-chains associated with the logic Cω
- Creator:
- Quiroga, Verónica and Fernández, Víctor
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- paraconsistent logic, algebraic logic, and dualities for ordered structures
- Language:
- English
- Description:
- In this paper we present a topological duality for a certain subclass of the Fω-structures defined by M. M. Fidel, which conform to a non-standard semantics for the paraconsistent N. C. A. da Costa logic Cω. Actually, the duality introduced here is focused on Fω-structures whose supports are chains. For our purposes, we characterize every Fω-chain by means of a new structure that we will call down-covered chain (DCC) here. This characterization will allow us to prove the dual equivalence between the category of Fω-chains and a new category, whose objects are certain special topological spaces (together with a distinguished family of open sets) and whose morphisms are particular continuous functions.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1093. A topological space is strongly paracompact if and only if for any monotone increasing open cover of it there exists a star-finite open refinement
- Creator:
- Qu, Han-Zhang
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- paracompact property and strongly paracompact property
- Language:
- English
- Description:
- We get the following result. A topological space is strongly paracompact if and only if for any monotone increasing open cover of it there exists a star-finite open refinement. We positively answer a question of the strongly paracompact property.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1094. A trapezium born in a bipolar nebula
- Creator:
- Neckel, Th., Staude, H. J., and Meisenheimer, K.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- observations, bipolar nebulae, and trapezium
- Language:
- Czech
- Description:
- We present various observations of the bipolar nebula No. 14 from the list of Neckel and Staude (1984): CCD images at 7 different wavelengths, spectroscopy at intermediate resolution between 4800 A and 9500 A, and CCD stellar polarimetry. The centra! star turns out to be a "Trapezium" consisting of four stars of spectral types between B0.5 and A5. The nebular spectrum is that of a low excited HII region, but in addition it exhibits a strong Ol 8446 line excited by Lyman β fluorescence. This requires a very high optical depth in Hα γ ≥ 1000) in the emitting region, which has been spatially resolved in NS 14. The stellar polarimetry, combined with the surface polarimetry of Scarrott et al. (1986), indicates that the polarization in the nebula can be explained by pure scattering alone.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1095. A treatment of a determinant inequality of Fiedler and Markham
- Creator:
- Lin, Minghua
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- matematika, mathematics, determinant inequality, partial trace, 13, and 51
- Language:
- English
- Description:
- Fiedler and Markham (1994) proved {\left( {\frac{{\det \hat H}}{k}} \right)^k} \geqslant \det H, where H = (H_{ij})_{i,j}^{n}_{=1} is a positive semidefinite matrix partitioned into n × n blocks with each block k × k and \hat H = \left( {tr{H_{ij}}} \right)_{i,j = 1}^n. We revisit this inequality mainly using some terminology from quantum information theory. Analogous results are included. For example, under the same condition, we prove \det \left( {{I_n} + \hat H} \right) \geqslant \det {\left( {{I_{nk}} + kH} \right)^{{1 \mathord{\left/ {\vphantom {1 k}} \right. \kern-\nulldelimiterspace} k}}}., Minghua Lin., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1096. A tree as a finite nonempty set with a binary operation
- Creator:
- Nebeský, Ladislav
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- trees, geodetic graphs, and binary operations
- Language:
- English
- Description:
- A (finite) acyclic connected graph is called a tree. Let W be a finite nonempty set, and let H(W) be the set of all trees T with the property that W is the vertex set of T. We will find a one-to-one correspondence between H(W) and the set of all binary operations on W which satisfy a certain set of three axioms (stated in this note).
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1097. A two-stage learning method to configure RBF centers and widths in dynamic environment employing immune operations
- Creator:
- Ling, Xiaofeng, Gong, Xinbao, Zang , Xiaogang, and Ronghong, Jin
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- RBF neural network, dynamics problems, and immune evolutionary mechanism
- Language:
- English
- Description:
- This paper proposes an immunity-based RBF training algorithm for nonlinear dynamic problems. Exploiting the locally-tuned structure of RBF network through immunological metaphor, a two-stage learning technique is proposed to configure RBF centers and widths in the hidden layer. Inspired by affinity maturation process of immune response, immune evolutionary mechanism (IEM) with memory operations is implemented in the learning stages to dynamically fine-tune the network performance. Experiment results also demonstrate that the algorithm has reached good performance with relatively low computational efforts in dynamic environments.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1098. A two-stage stochastic optimization model for a gas sale retailer
- Creator:
- Maggioni, Francesca, Vespucci, Maria Teresa, Allevi, Elisabetta , Bertocchi, Marida, and Innorta, Mario
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- gas sale company, mean reverting process, and stochastic programming
- Language:
- English
- Description:
- The paper deals with a new stochastic optimization model, named OMoGaS-SV (Optimization Modelling for Gas Seller-Stochastic Version), to assist companies dealing with gas retail commercialization. Stochasticity is due to the dependence of consumptions on temperature uncertainty. Due to nonlinearities present in the objective function, the model can be classified as an NLP mixed integer model, with the profit function depending on the number of contracts with the final consumers, the typology of such consumers and the cost supported to meet the final demand. Constraints related to a maximum daily gas consumption, to yearly maximum and minimum consumption in order to avoid penalties and to consumption profiles are included. The results obtained by the stochastic version give clear indication of the amount of losses that may appear in the gas seller's budget and are compared with the results obtained by the deterministic version (see Allevi et al. \cite{ABIV}).
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1099. A two-stage VoIP spam identification framework
- Creator:
- Ebrahim , Gamal A. and Younis, Akmal A:
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- VoIP, SPAM, SIP, SPIT, reputation lists, and fuzzy-logic controller
- Language:
- English
- Description:
- Identifying a VoIP call as SPAM based on call characteristics is an important issue that has never been studied before. Most of the studies of VoIP SPAM impose the whole burden on the callee to judge SPAM calls. In other words, the accuracy of the identification process is totally based on the callee identifying the call as SPAM, which is questionable and not reliable. In this paper, a two-stage VoIP SPAM identification framework is introduced. The first stage is a pre-call identification process, which uses a set of parameters about the call that can be collected before allowing the call to go through. The second stage is a post-call identification process that uses other parameters that can be collected during/after the call. The first stage provides a pre-call evaluation score of the call, while the second stage further tunes this score. In the proposed framework, the decision of identifying VoIP SPAM calls is based on several uncertain parameters that represent meta-data of VoIP calls. These parameters include call duration, amount of exchanged information in each direction, and calling pattern. In this study, the potential set of parameters that can be used to identify VoIP SPAM are investigated. A set of rules is used in addition to any prior evaluation of the caller to provide the pre-call score. Then, a fuzzy-logic controller is developed to identify VoIP SPAM in the second stage. An augmented ongoing tuning strategy is adopted where callee feedback, if any, is taken into account to further tune the identification process. Simulation studies are carried out to demonstrate the effectiveness of the two-stage approach in identifying VoIP SPAM based on the proposed framework.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1100. A two-zone model for longitudinal dispersion in channels with idealized pools nd riffles
- Creator:
- Valentine, Eric M., Zulfiqar, Ali, and Swailes, David C.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- dispersion, open-channel flow, dead zones, pools and riffles, numerical model, disperze, proudění v otevřených korytech, mrtvé zóny, tůně a prahy, and numerický model
- Language:
- Slovak
- Description:
- A one-dimensional two-zone mathematical model, comprising a pair of advection-dispersion equations coupled by a mass exchange term, is proposed to study longitudinal dispersion in channels with sequences of pools and riffles. An implicit finite-difference numerical scheme is employed, and its effectiveness is assessed with reference to known analytical solutions. Moreover, sets of longitudinal dispersion experiments were performed on various simple geometries of sequences of pools and riffles developed in a laboratory flume. The results were compared with corresponding numerical solutions to calibrate the two-zone model. and Pro studium podélné disperze v korytech s opakující se soustavou tůní a prahů byl navržen jednorozměrný dvouzónový matematický model. Model zahrnuje dvojici rovnic pro advektivní disperzi doplněných výrazem pro přenos hmoty. Byl použit implicitní model konečných diferencí a jeho vhodnost ověřena porovnáním se známým analytickým řešením. Navíc, v laboratorním žlabu byla provedena série měření podélné disperze pro různé jednoduché geometrie koryta se střídajícími se tůněmi a prahy. Pro kalibraci dvouzónového modelu byly výsledky měření porovnány s odpovídajícími matematickými řešeními.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public