Search results for " function"
showing 10 items of 9395 documents
The Psychology of Fluent Use
2016
In a perfect world, it would always be possible to operate technology effortlessly and to reach the desired goal. However, in the real world many factors may make technologies difficult to use or even hinder people from using technical artefacts. Most of these factors pertain to usability (i.e., technology’s ability to fit users’ capabilities) and thus concern technological solutions from the point of view of human beings as users of technology. Therefore, designing technical artefacts that are easy to use requires understanding the psychological and mental preconditions for using technology.
The management of the slow transit constipation in the laparoscopic era
2018
The slow transit constipation (STC) is a functional bowel pathology with slow total gut transit time with normal calibre colon in addition to a variety of other systemic symptoms. Patients with an abnormal colonic motility refractory to conservative treatment are regarded as appropriate candidates for surgery. Laparoscopic total colectomy with ileum-rectum anastomosis represents the commonest surgical operation in the treatment of STC, in well selected patients, after failure of conservative treatment. From 2012 to 2016, 8 patients suffering constipation according to Roma III criteria and diagnosed as STC were submitted to a total colectomy in our O.U. We evaluated the long-term post-operat…
Neue Therapieoption für akute hepatische Porphyrien
2021
Was ist neu? Therapie mit Givosiran Givosiran ist ein kleines synthetisches doppelsträngiges siRNA-Fragment mit 20 Basenpaaren Länge. Eine prospektive, randomisierte multizentrische Studie (Envision) zeigte erstmalig die klinische Wirksamkeit von monatlich subkutan applizierten synthetischen RNA-Molekülen („small interfering“ RNA, siRNA) zur Prävention von Attacken bei akuten hepatischen Porphyrien (AHP) 2. Die Koppelung von siRNA-Molekülen an N-Acetyl-Galaktosamin (GalNAc) und die hierdurch leberspezifische Aufnahme durch den Asialoglykoprotein-Rezeptor auf Hepatozyten sind ein Meilenstein in der Hepatologie. Dies führt zu einer hochselektiven Inhibition der Translation der bei AHP überexp…
Further results on H<inf>&#x221E;</inf> control of switched linear time-delay systems
2012
In this note, we study the problems of stability analysis and H ∞ controller synthesis of discrete-time switched systems with time-varying delay. The system under consideration is firstly transformed into an interconnection system. Based on the system transformation and the scaled small gain theorem, the asymptotic stability of the original system is examined via the version of the bounded realness of the transformed forward system. The aim of the proposed approach is to reduce conservatism, which is made possible by a precise approximation of the time-varying delay and the input-output approach. The proposed stability condition is demonstrated to be much less conservative than most existin…
Boundedness and spectral invariance for standard pseudodifferential operators on anisotropically weighted LP-Sobolev spaces
1990
It is shown that pseudodifferential operators with symbols in the standard classes S ρ,δ m (ℝn) define bounded maps between large classes of weighted LP-Sobolev spaces where the growth of the weight does not have to be isotropic. Moreover, the spectrum is independent of the choice of the space.
Mappings of finite distortion: Monotonicity and continuity
2001
We study mappings f = ( f1, ..., fn) : Ω → Rn in the Sobolev space W loc (Ω,R n), where Ω is a connected, open subset of Rn with n ≥ 2. Thus, for almost every x ∈ Ω, we can speak of the linear transformation D f(x) : Rn → Rn, called differential of f at x. Its norm is defined by |D f(x)| = sup{|D f(x)h| : h ∈ Sn−1}. We shall often identify D f(x) with its matrix, and denote by J(x, f ) = det D f(x) the Jacobian determinant. Thus, using the language of differential forms, we can write
On the regularity of the Hardy-Littlewood maximal operator on subdomains of ℝn
2010
AbstractWe establish the continuity of the Hardy-Littlewood maximal operator on W1,p(Ω), where Ω ⊂ ℝn is an arbitrary subdomain and 1 < p < ∞. Moreover, boundedness and continuity of the same operator is proved on the Triebel-Lizorkin spaces Fps,q (Ω) for 1 < p,q < ∞ and 0 < s < 1.
Estimates of maximal functions measuring local smoothness
1999
Letη be a nondecreasing function on (0, 1] such thatη(t)/t decreases andη(+0)=0. Letf ∈L(I n ) (I≡[0,1]. Set $${\mathcal{N}}_\eta f(x) = \sup \frac{1}{{\left| Q \right|\eta (\left| Q \right|^{1/n} )}} \smallint _Q \left| {f(t) - f(x)} \right|dt,$$ , where the supremum is taken over all cubes containing the pointx. Forη=t α (0<α≤1) this definition was given by A.Calderon. In the paper we prove estimates of the maximal functions $${\mathcal{N}}_\eta f$$ , along with some embedding theorems. In particular, we prove the following Sobolev type inequality: if $$1 \leqslant p< q< \infty , \theta \equiv n(1/p - 1/q)< 1, and \eta (t) \leqslant t^\theta \sigma (t),$$ , then $$\parallel {\mathcal{N}}_…
Invertibility of Sobolev mappings under minimal hypotheses
2010
Abstract We prove a version of the Inverse Function Theorem for continuous weakly differentiable mappings. Namely, a nonconstant W 1 , n mapping is a local homeomorphism if it has integrable inner distortion function and satisfies a certain differential inclusion. The integrability assumption is shown to be optimal.
Maximal potentials, maximal singular integrals, and the spherical maximal function
2014
We introduce a notion of maximal potentials and we prove that they form bounded operators from L to the homogeneous Sobolev space Ẇ 1,p for all n/(n − 1) < p < n. We apply this result to the problem of boundedness of the spherical maximal operator in Sobolev spaces.