952 research outputs found
On spectral synthesis in varieties containing the solutions of inhomogeneous linear functional equations
As a continuation of our previous work \cite{KV2} the aim of the recent paper
is to investigate the solutions of special inhomogeneous linear functional
equations by using spectral synthesis in translation invariant closed linear
subspaces of additive/multiadditive functions containing the restrictions of
the solutions to finitely generated fields. The idea is based on the
fundamental work of M. Laczkovich and G. Kiss \cite{KL}. Using spectral
analysis in some related varieties we can prove the existence of special
solutions (automorphisms) of the functional equation but the spectral synthesis
allows us to describe the entire space of solutions on a large class of
finitely generated fields. It is spanned by the so-called exponential monomials
which can be given in terms of automorphisms of \cc and differential
operators. We apply the general theory to some inhomogeneous problems motivated
by quadrature rules of approximate integration \cite{KKSZ08}, see also
\cite{KKSZ} and \cite{KKSZW}
On spectral analysis in varieties containing the solutions of inhomogeneous linear functional equations
The aim of the paper is to investigate the solutions of special inhomogeneous
linear functional equations by using spectral analysis in a translation
invariant closed linear subspace of additive/multiadditive functions containing
the restrictions of the solutions to finitely generated fields. The application
of spectral analysis in some related varieties is a new and important trend in
the theory of functional equations; especially they have successful
applications in case of homogeneous linear functional equations. The foundation
of the theory can be found in M. Laczkovich and G. Kiss \cite{KL}, see also G.
Kiss and A. Varga \cite{KV}. We are going to adopt the main theoretical tools
to solve some inhomogeneous problems due to T. Szostok \cite{KKSZ08}, see also
\cite{KKSZ} and \cite{KKSZW}. They are motivated by quadrature rules of
approximate integration
Transparent Location Fingerprinting for Wireless Services
Detecting the user location is crucial in a wireless environment, not only for the choice of first-hop communication partners, but also for many auxiliary purposes: Quality of Service (availability of information in the right place for reduced congestion/delay, establishment of the optimal path), energy consumption, automated insertion of location-dependent info into a web query issued by a user (for example a tourist asking informations about a monument or a restaurant, a fireman approaching a disaster area). The technique we propose in our investigation tries to meet two main goals: transparency to the network and independence from the environment. A user entering an environment (for instance a wireless-networked building) shall be able to use his own portable equipment to build a personal map of the environment without the system even noticing it. Preliminary tests allow us to detect position on a map with an average uncertainty of two meters when using information gathered from three IEEE802.11 access points in an indoor environment composed of many rooms on a 625sqm area. Performance is expected to improve when more access points will be exploited in the test area. Implementation of the same techniques on Bluetooth are also being studied
On the maximum values of the additive representation functions
Let and be sets of nonnegative integers. For a positive integer
let denote the number of representations of as the sum of two
terms from . Let and
\displaystyle d_{A,B}(x) = \max_{\hbox{t: a_{t} \le xb_{t} \le
x}}|a_{t} - b_{t}|. In this paper we study the connection between ,
and . We improve a result of Haddad and Helou about the
Erd\H{o}s - Tur\'an conjecture
A szervezeti elkötelezettség és a munka-család konfliktus összefüggései az ügyfélszolgálati munkában = Organizational Commitment and Work-Family Conflict in Customer Service Centres
Jelen disszertáció célja, hogy új tudományos ismeretekkel szolgáljon a szervezeti elkötelezettségnek az előzményeiről valamint a munka-család konfliktussal való összefüggéséről azáltal, hogy a kérdést egy a téma szempontjából releváns és általános tanulságok alapjául szolgálható kontextusban vizsgálja: ügyfélszolgálati szervezeteknél. Önkitöltős kérdőívek révén mértük fel a vizsgálatba bevont ügyfélszolgálati szervezetek munkavállalóinak szervezeti elkötelezettségét, a szervezeti elkötelezettségük előzményváltozóit, illetve a munkavállalók által megélt munka-család konfliktust. Sokváltozós matematikai statisztikai eszközök alkalmazásával elemeztük a változók alakulását illetve egymással való összefüggését
Newly identified YSO candidates towards the LDN 1188
We present an analysis of Young Stellar Object (YSO) candidates towards the
LDN 1188 molecular cloud. The YSO candidates were selected from the WISE
all-sky catalogue, based on a statistical method. We found 601 candidates in
the region, and classified them as Class I, Flat and Class II YSOs. Groups were
identified and described with the Minimal Spanning Tree (MST) method.
Previously identified molecular cores show evidence of ongoing star formation
at different stages throughout the cloud complex.Comment: 4 pages, 4 figures, 2 table
On minimal additive complements of integers
Let . If , then the set is
called an additive complement to in . If no proper subset of
is an additive complement to , then is called a minimal additive
complement. Let . If there exists a positive integer
such that for all sufficiently large integers , then we call
eventually periodic. In this paper, we study the existence of a minimal
complement to when is eventually periodic or not. This partially
answers a problem of Nathanson.Comment: 13 page
Discovery of the spectroscopic binary nature of the Cepheids X Puppis and XX Sagittarii
We present the analysis of photometric and spectroscopic data of two bright
Galactic Cepheids, X Puppis and XX Sagittarii. Based on the available data in
the literature as well as own observations spanning 75 years, we conclude that
both Cepheids belong to spectroscopic binary systems. However, the data are not
sufficient to determine the orbital periods nor other elements for the orbit.
This discovery corroborates the statement on the high frequency of occurrence
of binaries among the classical Cepheids, a fact to be taken into account when
calibrating the period-luminosity relationship for Cepheids. The photometric
data revealed that the pulsation period of X Pup is continuously increasing
with Delta P=0.007559 d/century likely caused by stellar evolution. The
pulsation period of XX Sgr turned out to be very stable in the last ~100 years.Comment: 6 pages, 5 figure
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