Search results for "DIR"
showing 10 items of 10242 documents
4-Manifold topology I: Subexponential groups
1995
The technical lemma underlying the 5-dimensional topological s-cobordism conjecture and the 4-dimensional topological surgery conjecture is a purely smooth category statement about locating ~-null immersions of disks. These conjectures are theorems precisely for those fundamental groups ("good groups") where the ~l-null disk lemma (NDL) holds. We expand the class of known good groups to all groups of subexponential growth and those that can be formed from these by a finite number of application of two opera- tions: (1) extension and (2) direct limit. The finitely generated groups in this class are amenable and no amenable group is known to lie outside this class.
Nilpotent-like fitting formations of finite soluble groups
2000
[EN] In this paper the subnormal subgroup closed saturated formations of finite soluble groups containing nilpotent groups are fully characterised by means of extensions of well-known properties enjoyed by the formation of all nilpotent groups.
OnF-Subnormal Subgroups andF-Residuals of Finite Soluble Groups
1996
All groups that we consider are finite and soluble. Recall that a formation is a class of groups which is closed under homomorphic images and subdirect products. Hence, if F is a formation and G is a group which is a direct product of the subgroups A and B, then G is in F if and only if A and B lie in F. More generally, Doerk and w x Hawkes 4, IV, 1.18 proved that if G is a group such that G s A = B, then G s A = B , where G is the F-residual of G, that is, the smallest normal subgroup of G with quotient in F. The main purpose of this paper is the development of this result by means of the concept of F-subnormal subgroup. Suppose that F is a saturated formation. A maximal subgroup M of a Ž …
Quasi-Modes in Higher Dimension
2019
Recall that if a(x, ξ) and b(x, ξ) are two C1-functions defined on some domain in \({\mathbf {R}}^{2n}_{x,\xi }\), then we can define the Poisson bracket to be the C0-function on the same domain given by $$\displaystyle \{ a,b\} =a^{\prime }_\xi \cdot b^{\prime }_x-a^{\prime }_x \cdot b^{\prime }_\xi =H_a(b). $$ Here \(H_a=a^{\prime }_\xi \cdot \partial _x-a^{\prime }_x\cdot \partial _\xi \) denotes the Hamilton vector field of a. The following result is due to Zworski, who obtained it via a semi-classical reduction from the above mentioned result of Hormander. A direct proof was given in Dencker et al. and here we give a variant. We will assume some familiarity with symplectic geometry.
An algorithm for the Rural Postman problem on a directed graph
1986
The Directed Rural Postman Problem (DRPP) is a general case of the Chinese Postman Problem where a subset of the set of arcs of a given directed graph is ‘required’ to be traversed at minimum cost. If this subset does not form a weakly connected graph but forms a number of disconnected components the problem is NP-Complete, and is also a generalization of the asymmetric Travelling Salesman Problem. In this paper we present a branch and bound algorithm for the exact solution of the DRPP based on bounds computed from Lagrangean Relaxation (with shortest spanning arborescence sub-problems) and on the fathoming of some of the tree nodes by the solution of minimum cost flow problems. Computation…
El desarrollo de los instrumentos de proteccion de los derechos de las mujeres en los sistemas regionales de derechos humanos. B. Sistema interameric…
2015
El artículo analiza los instrumentos de protección de los derechos de las mujeres en el marco del Sistema interamericano de derechos humanos y la actividad de la Organización de los Estados Americanos sobre igualdad de género, con especial atención a la labor de la Comisión Interamericana de Mujeres y a la Relatoría sobre los Derechos de las Mujeres.
NUEVAS DIRECTRICES SOBRE EL USO DE LOS TESTS: INVESTIGACIÓN, CONTROL DE CALIDAD Y SEGURIDAD
2015
Antecedentes. Para llevar a cabo una evaluación psicológica rigurosa es necesario que los profesionales que la realizan tengan una preparación adecuada, que los tests utilizados muestren unas buenas propiedades psicométricas, y que se utilicen de forma correcta. El objetivo de este trabajo es presentar las directrices recientes de la Comisión Internacional de Tests sobre el uso de los tests en tres ámbitos: investigación, control de calidad y seguridad en el manejo de las pruebas. Método. Se revisarán y comentarán los directrices recientes desarrolladas por la Comisión Internacional de Tests. Resultados. Las nuevas directrices sobre el uso de los tests ofrecen todo un conjunto de recomendac…
Nuevas directrices sobre el uso de los test: investigación, control de calidad y seguridad
2015
Contiene versión en inglés