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182. A class of torsion-free abelian groups characterized by the ranks of their socles
- Creator:
- Albrecht, Ulrich, Giovannitti, Tony, and Goeters, Pat
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Dedekind domain
- Language:
- English
- Description:
- Butler groups formed by factoring a completely decomposable group by a rank one group have been studied extensively. We call such groups, bracket groups. We study bracket modules over integral domains. In particular, we are interested in when any bracket $R$-module is $R$ tensor a bracket group.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
183. A class of weakly perfect graphs
- Creator:
- Maimani, H. R., Pournaki, M. R., and Yassemi, S.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chromatic number, clique number, and weakly perfect graph
- Language:
- English
- Description:
- A graph is called weakly perfect if its chromatic number equals its clique number. In this note a new class of weakly perfect graphs is presented and an explicit formula for the chromatic number of such graphs is given.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
184. A classification of the "full" words (shi2zi4) (1) of the vernacular Chinese of the III-V centuries
- Creator:
- Gurevich, Isabella
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- classification and China
- Language:
- English
- Description:
- The aim of this paper is to rank the words of the Chinese language of the III-V centuries in a number of classes that differ in their grammatical characteristics. The classification undertaken is based on syntactic criteria.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
185. A cluster procedure for small frequencies: crisp data, fuzzy distances, crisp clusters
- Creator:
- Pokorny, Dan and Stigler, Michael
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- hierarchical cluster analysis, frequency vectors, fuzzy distances, Bayesian estimation, two-class cluster analysis, guided imagery, daydream, and CCRT
- Language:
- English
- Description:
- (i) The procedure introduced here for the clustering of frequency vectors takes into account the uncertainty arising from dealing with small observed frequencies. The smaller observed absolute frequencies, the more uncertainty about the “true” probability vector. The object is not represented by a single point in the multidimensional space but rather by the fuzzy set spread around this point. Consequently, the distance between two such objects is a fuzzy value, too. The expected mean distance between two objects generally differs from the simple distance: for instance, two objects with the same frequency vectors have a positive mean distance. The exact formula for estimation of the mean distance is given; this makes the algorithmization of the proposed procedure possible. The approach corresponds to that of the Bayesian estimation. The matrix of expected mean distances is an input to the hierarchical cluster analysis. (ii) The conventional hierarchical cluster analysis investigates similarities between objects from a given class. A modified general procedure is proposed seeking analogies between two classes of objects. The “two-class cluster analysis” is applicable to any kind of objects to be clustcred; it is not confined to the herein discussed special case of frequency vectors. (iii) The development of the procedure was developed initially for the field of the psychotherapy research - investigation of relationship patterns found within verbatirn protocols of sessions using the “guided imagery”, a psychotherapy technique dealing with evoked daydrearns. This constitutes an application example.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
186. A cohomological Steinness criterion for holomorphically spreadable complex spaces
- Creator:
- Vâjâitu, Viorel
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Stein space, 1-convex space, branched Riemannian domain, holomorphically spreadable complex space, and structurally acyclic space
- Language:
- English
- Description:
- Let $X$ be a complex space of dimension $n$, not necessarily reduced, whose cohomology groups $H^1(X,{\cal O}), \ldots , H^{n-1}(X,{\cal O})$ are of finite dimension (as complex vector spaces). We show that $X$ is Stein (resp., $1$-convex) if, and only if, $X$ is holomorphically spreadable (resp., $X$ is holomorphically spreadable at infinity). \endgraf This, on the one hand, generalizes a known characterization of Stein spaces due to Siu, Laufer, and Simha and, on the other hand, it provides a new criterion for $1$-convexity.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
187. A combined approach to adaptive differential evolution
- Creator:
- Poláková, Radka and Tvrdík, Josef
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Global optimization, differential evolution, adaptation, combined adaptive mechanism, and experimental comparison
- Language:
- English
- Description:
- The paper deals with the adaptive mechanisms in differential evolution (DE) algorithm. DE is a simple and effective stochastic algorithm frequently used in solving the real-world global optimization problems. The efficiency of the algorithm is sensitive to setting its control parameters. Several adaptive approaches have appeared recently in order to avoid control-parameter tuning. A new adaptive variant of differential evolution is proposed in this study. It is based on a combination of two adaptive approaches published before. The new algorithm was tested on the well-known set of benchmark problems developed for the special session of CEC2005 at four levels of population size and its performance was compared with the adaptive variants that were applied in the design of the new algorithm. The new adaptive DE variant outperformed the others in several test problems but its efficiency on average was not better.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
188. A comment on the opening passage of the Amarna Letters - its structure and its address
- Creator:
- Mynářová, Jana
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- literature
- Language:
- English
- Description:
- The present article concentrates on an analysis of the structure of the opening passages and means of address in the Amarna Letters, one of the largest sources of epistolary documents, written during the 2nd half of the 2nd millennium B.C. From the first look at the Amarna corrpus, those familiar with the topic will notice a formal structure very similar to the one found in other letters written in Peripheral Akkadian. However, the discussion on the formal structure usually limits itself to several short statements and general descriptive comments.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
189. A compactness result for polyharmonic maps in the critical dimension
- Creator:
- Zheng, Shenzhou
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- singularity (matematika), mathematics, singularities (mathematics), polyharmonic map, compactness, Coulomb moving frame, Palais-Smale sequence, removable singularity, 13, and 51
- Language:
- English
- Description:
- For n=2m\geqslant 4, let \Omega\in \mathbb{R}^{n} be a bounded smooth domain and N\subset \mathbb{R}^{L} a compact smooth Riemannian manifold without boundary. Suppose that \left \{ uk \right \}\in W^{m,2}\left ( \Omega ,N \right ) is a sequence of weak solutions in the critical dimension to the perturbed m-polyharmonic maps \frac{{\text{d}}}{{{\text{dt}}}}\left| {_{t = 0}{E_m}({\text{II}}(u + t\xi )) = 0} \right with Ωk → 0 in W^{m,2}\left( \Omega ,N \right )* and {u_k} \rightharpoonup u weakly in W^{m,2}\left( \Omega ,N \right ). Then u is an m-polyharmonic map. In particular, the space of m-polyharmonic maps is sequentially compact for the weak- W^{m,2} topology., Shenzhou Zheng., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
190. A comparative study of HMMs and DBNs applied to Facial Action Units Recognition
- Creator:
- Popa, M. C., Rothkrantz , L. J. M., Datcu , D., Wiggers, P., Braspenning , R., and Shan, C.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Hidden Markov Models, Dynamic Bayesian Networks, Facial Action Units Recognition, and Facial Action Coding System
- Language:
- English
- Description:
- From a theoretical point of view, Hidden Markov Models (HMMs) and Dynamic Bayesian Networks (DBNs) are similar, still in practice they pose different challenges and perform in a different manner. In this study we present a comparative analysis of the two spatial-temporal classification methods: HMMs and DBNs applied to the Facial Action Units (AUs) recognition problem. The Facial Action Coding System (FACS) developed by Ekman and Friesen decomposes the face into 46 AUs, each AU being related to the contraction of one or more specific facial muscles. FACS proved its applicability to facial behavior modeling, enabling the recognition of an extensive palette of facial expressions. Even though a lot has been published on this theme, it is still difficult to draw a conclusion regarding the best methodology to follow, as there is no common basis for comparison and sometimes no argument is given why a certain classification method was chosen. Therefore, our main contributions reside in discussing and comparing the relative performance of the two proposed classifiers (HMMs vs. DBNs) and also of different Region of Interest (ROI) selections proposed by us and different optical flow estimation methods. We can consider our automatic system towards AUs classification an important step in the facial expression recognition process, given that even one emotion can be expressed in different ways, fact that suggests the complexity of the analyzed problem. The experiments were performed on the Cohn-Kanade database and showed that under the same conditions regarding initialization, labeling, and sampling, both classification methods produced similar results, achieving the same recognition rate of 89% for the classification of facial AUs. Still, by enabling non-fixed sampling and using HTK, HMMs rendered a better performance of 93% suggesting that they are better suited for the special task of AUs recognition.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public