Number of results to display per page
Search Results
672. A generalization of semiflows on monomials
- Creator:
- Kulosman, Hamid and Miller, Alica
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- monomial ideal, term ideal, Dickson's lemma, and semiflow
- Language:
- English
- Description:
- Let K be a field, A = K[X1, . . . , Xn] and M the set of monomials of A. It is well known that the set of monomial ideals of A is in a bijective correspondence with the set of all subsemiflows of the M-semiflow M. We generalize this to the case of term ideals of A = R[X1, . . . , Xn], where R is a commutative Noetherian ring. A term ideal of A is an ideal of A generated by a family of terms cXµ1 1 . . . Xµn n , where c ∈ R and µ1, . . . , µn are integers ≥ 0.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
673. A generalization of the Auslander transpose and the generalized Gorenstein dimension
- Creator:
- Geng, Yuxian
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- transpose, semidualizing module, generalized Gorenstein dimension, depth, and Auslander-Bridger formula
- Language:
- English
- Description:
- Let $R$ be a left and right Noetherian ring and $C$ a semidualizing $R$-bimodule. We introduce a transpose ${\rm Tr_{c}}M$ of an $R$-module $M$ with respect to $C$ which unifies the Auslander transpose and Huang's transpose, see Z. Y. Huang, On a generalization of the Auslander-Bridger transpose, Comm. Algebra 27 (1999), 5791–5812, in the two-sided Noetherian setting, and use ${\rm Tr_{c}}M$ to develop further the generalized Gorenstein dimension with respect to $C$. Especially, we generalize the Auslander-Bridger formula to the generalized Gorenstein dimension case. These results extend the corresponding ones on the Gorenstein dimension obtained by Auslander in M. Auslander, M. Bridger, Stable Module Theory, Mem. Amer. Math. Soc. vol. 94, Amer. Math. Soc., Providence, RI, 1969.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
674. A generalization of the finiteness problem of the local cohomology modules
- Creator:
- Abbasi, Ahmad and Roshan-Shekalgourabi, Hajar
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- local cohomology module, weakly Laskerian module, ${\mathfrak a}$-weakly Laskerian module, and associated prime
- Language:
- English
- Description:
- Let $R$ be a commutative Noetherian ring and ${\mathfrak a}$ an ideal of $R$. We introduce the concept of ${\mathfrak a}$-weakly Laskerian $R$-modules, and we show that if $M$ is an ${\mathfrak a}$-weakly Laskerian $R$-module and $s$ is a non-negative integer such that ${\rm Ext}^j_R(R/{\mathfrak a}, H^i_{{\mathfrak a}}(M))$ is ${\mathfrak a}$-weakly Laskerian for all $i<s$ and all $j$, then for any ${\mathfrak a}$-weakly Laskerian submodule $X$ of $H^s_{{\mathfrak a}}(M)$, the $R$-module ${\rm Hom}_R(R/{\mathfrak a},H^s_{{\mathfrak a}}(M)/X)$ is ${\mathfrak a}$-weakly Laskerian. In particular, the set of associated primes of $H^s_{\mathfrak a}(M)/X$ is finite. As a consequence, it follows that if $M$ is a finitely generated $R$-module and $N$ is an ${\mathfrak a}$-weakly Laskerian $R$-module such that $ H^i_{{\mathfrak a}}(N)$ is ${\mathfrak a}$-weakly Laskerian for all $i<s$, then the set of associated primes of $H^s_{\mathfrak a}(M, N)$ is finite. This generalizes the main result of S. Sohrabi Laleh, M. Y. Sadeghi, and M. Hanifi Mostaghim (2012).
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
675. A generalization of the Gauss-Lucas theorem
- Creator:
- Díaz-Barrero, J. L. and Egozcue, J. J.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- polynomials, location of zeros, convex hull of the zeros, and Gauss-Lucas theorem
- Language:
- English
- Description:
- Given a set of points in the complex plane, an incomplete polynomial is defined as the one which has these points as zeros except one of them. The classical result known as Gauss-Lucas theorem on the location of zeros of polynomials and their derivatives is extended to convex linear combinations of incomplete polynomials. An integral representation of convex linear combinations of incomplete polynomials is also given.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
676. A generalized bivariate lifetime distribution based on parallel-series structures
- Creator:
- Mohtashami-Borzadaran, Vahideh , Amini , Mohammad , and Ahmadi, Jafar
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- copula, distortion, extreme-value copula, dependence measures, and competing risks
- Language:
- English
- Description:
- In this paper, a generalized bivariate lifetime distribution is introduced. This new model is constructed based on a dependent model consisting of two parallel-series systems which have a random number of parallel subsystems with fixed components connected in series. The probability that one system fails before the other one is measured by using competing risks. Using the extreme-value copulas, the dependence structure of the proposed model is studied. Kendall's tau, Spearman's rho and tail dependences are investigated for some special cases. Simulation results are given to examine the effectiveness of the proposed model.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
677. A generalized maximum principle for boundary value problems for degenerate parabolic operators with discontinuous coefficients
- Creator:
- Bonafede, Salvatore and Nicolosi, Francesco
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- weak subsolution, generalized maximum principle, comparison theorem, and degenerate equation
- Language:
- English
- Description:
- We prove a generalized maximum principle for subsolutions of boundary value problems, with mixed type unilateral conditions, associated to a degenerate parabolic second-order operator in divergence form.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
678. A generalized method of estimating star corrections from latitude and time observations
- Creator:
- Hefty, Ján
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- astronomical latitude-longitude measurements and estimating star corrections
- Language:
- Czech
- Description:
- Long periods of regular astronomical latitude-longitude measurements on observatories participating in determination of Earth´s rotation parameters are frequently used for estimation of corrections to star catalogue mean places and proper motions. The proposed method is the extension and generalization of the usually exploited chain method. It is possible to estimate simultaneously the corrections of declinations and right ascensions for instruments which determine both latitude and longitude. Additional unknowns - amplitudes of short-periodic terms (e.g. corrections to nutation amplitudes, tidal variations, nearly diurnal polar motion, instrumental parameters and refraction anomalies) can be included into total adjustment. It is not necessary to fulfil the condition of closing the chain. The constraint for unknown parameters is the minimum of choosen guadratic form. The problem is solved by using the theory of generalized inverse of matrices. The method is demonstrated on determination of the right ascension corrections from observations with visual transit instrument. Another applications of proposed method are outlined.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
679. A generalized notion of n-weak amenability
- Creator:
- Bodaghi, Abasalt and Shojaee, Behrouz
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Banach algebra, continuous homomorphism, (ϕ, ψ)-derivation, and n-weak amenability
- Language:
- English
- Description:
- In the current work, a new notion of n-weak amenability of Banach algebras using homomorphisms, namely (ϕ, ψ)-n-weak amenability is introduced. Among many other things, some relations between (ϕ, ψ)-n-weak amenability of a Banach algebra A and Mm(A), the Banach algebra of m × m matrices with entries from A, are studied. Also, the relation of this new concept of amenability of a Banach algebra and its unitization is investigated. As an example, it is shown that the group algebra L 1 (G) is (ϕ, ψ)-n-weakly amenable for any bounded homomorphisms ϕ and ψ on L 1 (G).
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
680. A geometric algorithm for the output functional controllability in general manipulation systems and mechanisms
- Creator:
- Mercorelli, Paolo
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- geometric approach, manipulators, and functional controllability
- Language:
- English
- Description:
- In this paper the control of robotic manipulation is investigated. Manipulation system analysis and control are approached in a general framework. The geometric aspect of manipulation system dynamics is strongly emphasized by using the well developed techniques of geometric multivariable control theory. The focus is on the (functional) control of the crucial outputs in robotic manipulation, namely the reachable internal forces and the rigid-body object motions. A geometric control procedure is outlined for decoupling these outputs and for their perfect trajectory tracking. The control of robotic manipulation is investigated. These are mechanical structures more complex than conventional serial-linkage arms. The robotic hand with possible inner contacts is a paradigm of general manipulation systems. Unilateral contacts between mechanical parts make the control of manipulation system quite involved. In fact, contacts can be considered as unactuated (passive) joints. The main goal of dexterous manipulation consists of controlling the motion of the manipulated object along with the grasping forces exerted on the object. In the robotics literature, the general problem of force/motion control is known as "hybrid control". This paper is focused on the decoupling and functional controllability of contact forces and object motions. The goal is to synthesize a control law such that each output vector, namely the grasping force and the object motion, can be independently controlled by a corresponding set of generalized input forces. The functional force/motion controllability is investigated. It consists of achieving force and motion tracking with no error on variables transients. The framework used in this paper is the geometric approach to the structural synthesis of multivariable systems.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public