We prove an algebraic extension theorem for the computably enumerable sets, E . Using this extension theorem and other work we then show: If A and  are automorphic via Ψ then they are automorphic via Λ where Λ ↾ L∗(A) = Ψ and Λ ↾ E∗(A) is ∆ 3 . We give an algebraic description of when an arbitrary set  is in the orbit of a computably enumerable set A. We construct the first example of a defin...

The Advanced Photon Source uses two distinct control programs for orbit control and stability—a full-featured workstation-based program for orbit control (sddscontrollaw) and an EPICS-based system, the RealTime Fast Feedback System (RTFS), to reduce orbit motion. The sddscontrollaw program has been ported to EPICS and moved from the UNIX environment to an EPICS IOC attached to the RTFS. This EP...

Orbit feedback controllers are indispensable for the operation of modern particle accelerators. Many such controllers are based on the decoupling of the inputs and outputs of the system to be controlled with the help of the singular value decomposition (SVD controller). It is crucial to verify the stability of SVD controllers, also in the presence of mismatches between the used accelerator mode...

INTRODUCTION Tumors of the orbit are diagnosed sporadically. Based on the tumor registry of the American Cancer Society the incidence of tumors of the orbit is assessed at fewer than 1 per 100 000 persons. Tumors of the orbit can be divided into three groups: primary tumors, tumors penetrating the orbit from neighboring structures, and tumors that are metastases of malignant cancers from distan...

In the last ten years significant advances have been made in gravity field modelling, culminating in general-purpose models like JGM-3, TEG-3 and EGM96. Significant defects remain in the quality of the models when applied to orbit determination of some altimeter satellites, leading to large orbit errors, characterised by the geographically-correlated nature of the altimeter crossover height dif...

The influence of spin-orbit coupling in two-dimensional systems is investigated within the framework of the Landauer-Büttiker coherent scattering formalism. After a short review of the features of spin-orbit coupling in two-dimensional electron gases, we define the creation and annihilation operators for the stationary states of the Rashba spin-orbit coupling Hamiltonian and use them to calcula...

Usually considered a morphologically conservative group, didelphid marsupials present considerable variation in ecology and body size, some of which were shown to relate to morphological structures. Thus, changes on orbit morphology are likely and could be related to that variation. We calculated orbit orientation in 873 specimens of 16 Didelphidae genera yielding estimates of orbits convergenc...

A micro anatomical and surgical study of the orbit was conducted on cadaver specimens. First of all we reviewed the anatomy of the orbit with special emphasis on microanatomical structures. Three neurosurgical approches are then described with all structures encountered along these routes. The superior approach which provides a good access to the superior part of the orbit is the only route whi...

In this paper we introduce a general methodology for computing numerically the normal form around a periodic orbit of an autonomous analytic Hamiltonian system The process follows two steps First we expand the Hamiltonian in suit able coordinates around the orbit and second we perform a standard normal form scheme based on the Lie series method This scheme is carried out up to some nite order a...