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121.
Empirical likelihood inference for censored median regression with weighted empirical hazard functions 总被引:1,自引:0,他引:1
In recent years, median regression models have been shown to be useful for analyzing a variety of censored survival data in
clinical trials. For inference on the regression parameter, there have been a variety of semiparametric procedures. However,
the accuracy of such procedures in terms of coverage probability can be quite low when the censoring rate is heavy. In this
paper, based on weighted empirical hazard functions, we apply an empirical likelihood (EL) ratio method to the median regression
model with censoring data and derive the limiting distribution of EL ratio. Confidence region for the regression parameter
can then be obtained accordingly. Furthermore, we compared the proposed method with the standard method through extensive
simulation studies. The proposed method almost always outperformed the existing method. 相似文献
122.
Characterizations are given of those linear partial differential operators with constant coefficients which admit a continuous linear right inverse on ε(ω()ω) )resp. ε[ω](Ω) and/or D′(ω)(Ω) (resp. D′[ω](Ω), where Ω is an open set in ?n. The characterisations are in the same spirit as in the previous results of the authors on the existence of right inverses on C∞ and/or D′(Ω). 相似文献
123.
Lucian Beznea 《Journal of Mathematical Analysis and Applications》2011,384(1):33-48
We obtain a criterion for the quasi-regularity of generalized (non-sectorial) Dirichlet forms, which extends the result of P.J. Fitzsimmons on the quasi-regularity of (sectorial) semi-Dirichlet forms. Given the right (Markov) process associated to a semi-Dirichlet form, we present sufficient conditions for a second right process to be a standard one, having the same state space. The above mentioned quasi-regularity criterion is then an application. The conditions are expressed in terms of the associated capacities, nests of compacts, polar sets, and quasi-continuity. The second application is on the quasi-regularity of the generalized Dirichlet forms obtained by perturbing a semi-Dirichlet form with kernels. 相似文献
124.
125.
Kathleen M. Fick Johnny Henderson William Yin 《Journal of Difference Equations and Applications》2013,19(4):371-387
Eventual right disfocality of a dynamic equation y j j ( t )+ p 1 ( t ) y j ( t )+ p 2 ( t ) y ( t )=0, t ] T is established where T is a time scale. The results are obtained by imposing integrability conditions on p 1 and p 2 . 相似文献
126.
Ada Peluso 《代数通讯》2013,41(9):3017-3025
ABSTRACT We study conditions on an ideal A of a self-injective R such that the factor ring R/ A is again self-injective, extending certain of our results for PF rings (Faith, 2006). We also consider the same question for p -injective, and for CS -rings. For the CS -rings we consider conditions under which A splits off as a ring direct factor, equivalently, when A is generated by a central idempotent. Definitive results are obtained for an ideal A which is semiprime as a ring, that is, has no nilpotent ideals except zero, and which is a right annihilator ideal. Then A is said to be an r -semiprime right annulet ideal, and is generated by a central idempotent in the following cases: (1) whenever A is generated by an idempotent as a right (or left) ideal (Theorems 3.4, 3.6); (2) in any Baer ring R (Theorem 3.5); (3) in any right and left CS -ring R (Theorem 4.2), and (4) in any right nonsingular right CS -ring R (Theorem 5.5). These results also generalize results of the author in Faith (1985), where it is proven that the maximal regular ideal M( R) splits off in any right and left continuous ring. The results are applied in Section 6 to extend theorems of Faith (1996) characterizing VNR rings, and, as the title of Faith (1996) suggests, extend the conjecture of Shamsuddin. 相似文献
127.
H. H. Brungs 《代数通讯》2013,41(11):3874-3903
A right cone H in a group G is a submonoid of G that generates G and aH ? bH for a, b ? H implies bH ? aH. With any right ideal I ≠ H of H a completely prime ideal P r (I) of H is associated and the set 𝒫(I) of right ideals I′ of H with the same associated prime ideal P′ =P r (I) is determined if P′·? P″ is a right invariant segment in H. The set 𝒫(I) is also described if P r (I) is a limit prime. 相似文献
128.
The aim of this article is the study of right nuclei of quasigroups with right unit element. We investigate an extension process in this category of quasigroups, which is defined by a slight modification of non-associative Schreier-type extensions of groups or loops. The main results of the article give characterizations of quasigroup extensions satisfying particular nuclear conditions. We apply these results for constructions of right nuclear quasigroup extensions with right inverse property. 相似文献
129.
Mason introduced the reflexive property for ideals, and then this concept was generalized by Kim and Baik, defining idempotent reflexive right ideals and rings. In this article, we characterize aspects of the reflexive and one-sided idempotent reflexive properties, showing that the concept of idempotent reflexive ring is not left-right symmetric. It is proved that a (right idempotent) reflexive ring which is not semiprime (resp., reflexive), can always be constructed from any semiprime (resp., reflexive) ring. It is also proved that the reflexive condition is Morita invariant and that the right quotient ring of a reflexive ring is reflexive. It is shown that both the polynomial ring and the power series ring over a reflexive ring are idempotent reflexive. We obtain additionally that the semiprimeness, reflexive property and one-sided idempotent reflexive property of a ring coincide for right principally quasi-Baer rings. 相似文献
130.
Simple right alternative superalgebras which have a simple algebra as even part and, as odd part, an irreducible bimodule over the even part are investigated. Under these conditions, superalgebras with one dimensional even part are classified, as well as superalgebras having M 2(F) as even part and a unital irreducible bimodule over M 2(F) of dimension less than or equal to 6 as odd part. It is shown that there is only a unique non alternative simple right alternative superalgebra of the first type and, for the second type, there is a infinite family depending on a single parameter. 相似文献