In this talk, we give a criterion for a companion matrix to be reducible and give a complete characterization of reducible companion matrices. We also consider properties of the numerical ranges of reducible companion matrices. To be more precise, if C is an n-by-n reducible companion matrix which is unitarily equivalent to the direct sum of A and B, we study properties of the numerical ranges ...

This research through comparison study of application of ICT on marketing of agricultural crops in khozestan province, evaluate the role of such factors. The study is of applied type and the method being used is descriptive- correlational. Statistical population of this research is all agricultural experts of Khuzestan province and using Cochran’s formula , a sample size of 144 members was sele...

Companion viruses have not received as much attention as their non-companion counterparts. To some extent this is due to the fact that only a small percentage of the computer viruses released into the computing world have been companion viruses. However, this may change in the near future. Companion viruses do not have size restrictions that noncompanion viruses have. Thus, these viruses can be...

We report on a near-infrared, long-baseline interferometric search for luminous companions to the star 51 Pegasi conducted with the Palomar Testbed Interferometer. Our data is completely consistent with a single-star hypothesis. We find no evidence to suggest a luminous companion to 51 Pegasi, and can exclude a companion brighter than a ∆K of 4.27 at the 99% confidence level for the 4.2-day orb...

In this paper, we propose a mobile user interface named personal companion which enables selection and interaction of u-services based on context of user. Personal companion selects u-services from a list of discovered services, supports camera-based selection with embedded marker and personalizes UI of the selected service in ubiquitous computing environment. In order to verify its usefulness,...

In this work, we present the development and evaluation of a social companion and conversation partner for the special user group of elderly. With the aim of designing a user-adaptive system, we responded to the desires of the elderly which have been identified during various interviews and created a companion which talks and listens to the elderly users. Moreover, we conducted a user study wit...

This review deals with aspects of the cellular and molecular biology of the sieve element/companion cell complex, the functional unit of sieve tubes in angiosperms. It includes the following issues: (a) evolution of the sieve elements; (b) the specific structural outfit of sieve elements and its functional significance; (c) modes of cellular and molecular interaction between sieve element and c...

We suggest that a neutron star with a strong magnetic field, spiraling into the envelope of a companion star, can generate a “companion induced SN-like off-center explosion”. The strongly magnetized neutron star (“magnetar”) is born in a supernova explosion before entering into an expanding envelope of a supergiant companion. If the neutron star collapses into a black hole via the hypercritical...

The concept of pseudospectra was introduced by Trefethen during the 1990s and became a popular tool to explain the behavior of non-normal matrices. It is well known that the zeros of a polynomial are equal to the eigenvalues of the associated companion matrix. It is feasible to do the sensitivity analysis of the zeros of polynomials by the tool of pseudospectra of companion matrices. Thus, the ...

The development of intelligent tutoring systems has long been the focus of applying artificial intelligence and cognitive science in education. A new breed of intelligent learning environments called learning companion systems was developed over a decade ago. In contrast to an intelligent tutoring system, in which a computer mimics an intelligent tutor, the learning companion system assumes two...