bluuebunny/crossref_metadata_2025 huggingface dataset:
On graded Ω-groups
Authors: Ilic-Georgijevic Emil
Published: January 2016

In this paper we study the notion of a graded ?-group (X;+ ?), but graded in
the sense of M. Krasner, i.e., we impose nothing on the grading set except
that it is nonempty, since operations of and the grading of (X,+) induce
operations (generally partial) on the grading set. We prove that graded
?-groups in Krasner?s sense are determined up to isomorphism by their
homogeneous parts, which, with respect to induced operations, represent
partial structures called ?-homogroupoids, thus narrowing down the theory of
graded -groups to the theory of ?-homogroupoids. This approach already proved
to be useful in questions regarding A. V. Kelarev?s S-graded rings inducing
S; where S is a partial cancellative groupoid. Particularly, in this paper
we prove that the homogeneous subring of a Jacobson S-graded ring inducing S
is Jacobson under certain assumptions. We also discuss the theory of prime
radicals for ?-homogroupoids thus extending results of A. V. Mikhalev, I. N.
Balaba and S. A. Pikhtilkov in a natural way. We study some classes of
?-homogroupoids for which the lower and upper weakly solvable radicals
coincide and also, study the question of the homogeneity of the prime
radical of a graded ring.
The Kurepa-Vandermonde matrices arising from Kurepa’s left factorial hypothesis
Authors: Mestrovic Romeo
Published: January 2016

Kurepa?s (left factorial) hypothesis asserts that for each integer n ? 2 the
greatest common divisor of !n := Pn-1?k=0 k! and n! is 2. It is known that
Kurepa?s hypothesis is equivalent to p-1?k=0 (-1)k/k!?/ 0 (mod p) for each
odd prime p, or equivalently, Sp-1 ?/ 0(modp) (i.e., Bp-1 ?/1(modp)) for
each odd prime p, where Sp-1 and Bp-1 are the (p-1)th derangement
number and the (p-1)th Bell number, respectively. Motivated by these two
reformulations of Kurepa?s hypothesis and a congruence involving the Bell
numbers and the derangement numbers established by Z.-W. Sun and D. Zagier
[28, Theorem 1.1], here we give two ?matrix? formulations of Kurepa?s
hypothesis over the field Fp, where p is any odd prime. The matrices Vp and
Cp which are involved in these ?matrix? formulations of Kurepa?s hypothesis
are the square (p-1)x(p-1) Vandermondelike matrices. Accordingly, Vp and
Cp are called the Kurepa-Vandermonde matrices. Furthermore, for each odd
prime p we determine det(Vp) and det(Cp) in the field Fp.
Family of simultaneous methods with corrections for approximating zeros of analytic functions
Authors: Rancic Lidija
Published: January 2016

A family of accelerated iterative methods for the simultaneous approximation
of complex zeros of a class of analytic functions is proposed. Considered
analytic functions have only simple zeros inside a simple smooth closed
contour in the complex plane. It is shown that the order of convergence of
the basic family can be increased from four to five and six using Newton?s
and Halley?s corrections, respectively. The improved convergence is achieved
on the account of additional calculations of low computational cost, which
significantly increases the computational efficiency of the accelerated
methods. Numerical examples demonstrate a good convergence properties,
fitting very well theoretical results.
Quadrature rules with an even number of multiple nodes and a maximal trigonometric degree of exactness
Authors: Tomovic Tatjana , Stanic Marija
Published: January 2016

This paper is devoted to the interpolatory quadrature rules with an even
number of multiple nodes, which have the maximal trigonometric degree of
exactness. For constructing of such quadrature rules we introduce and
consider the so-called s- and ?-orthogonal trigonometric polynomials. We
present a numerical method for construction of mentioned quadrature rules.
Some numerical examples are also included.
Lacunary ward continuity in 2-normed spaces
Authors: Cakalli Huseyin , Ersan Sibel
Published: January 2016

In this paper, we introduce lacunary statistical ward continuity in a
2-normed space. A function f defined on a subset E of a 2-normed space X is
lacunary statistically ward continuous if it preserves lacunary
statistically quasi-Cauchy sequences of points in E where a sequence (xk) of
points in X is lacunary statistically quasi-Cauchy if limr?1 1/hr |{k?Ir
: ||xk+1 - xk, z||? ?}| = 0 for every positive real number ? and z ? X, and
(kr) is an increasing sequence of positive integers such that k0 = 0 and hr
= kr - kr-1 ? ? as r ? ?, Ir = (kr-1, kr]. We investigate not only
lacunary statistical ward continuity, but also some other kinds of
continuities in 2-normed spaces.
New examples of partial samples from the uniform AR(1) process and asymptotic distributions of extremes
Authors: Glavas Lenka
Published: January 2016

The joint limiting distribution of maximum of the specific sub-sample and
maximum of the complete sample from the first-order auto-regressive process
with uniform marginal distributions is obtained in this article. There are
considered several examples of partial samples, consisted of non-randomly
selected terms of the full sample. It is well known that the uniform AR(1)
process is strictly stationary random sequence; it doesn?t satisfy condition
of weak dependency, that prohibits clustering of extremes. As a consequence
of this property, some interesting conclusions about joint asymptotic
distributions are reached.
An extension of two fixed point theorems of Fisher to partial metric spaces
Authors: Pavlovic Vladimir , Ilic Dejan , Rakocevic Vladimir
Published: January 2016

In S.G. Matthews [Partial metric topology, in: Proc. 8th Summer Conference on
General Topology and Applications, in: Ann. New York Acad. Sci., vol. 728,
1994, pp. 183-197], the author introduced and studied the concept of partial
metric space, and obtained a Banach type fixed point theorem on complete
partial metric spaces. The present paper forms part of the study of possible
extensions of metric fixed point results to the context of partial metric
spaces, in particular two theorems due to Fisher. The theory is illustrated
by some examples.
Monodromy groupoid of an internal groupoid in topological groups with operations
Authors: Mucuk Osman , Akız Fulya
Published: January 2016

In this paper, the monodromy groupoids of internal groupoids in the
topological groups with operations are studied and a monodromy principle for
internal groupoids in groups with operations is obtained.
Infinitesimal bending influence on the Willmore energy of curves
Authors: Najdanovic Marija
Published: January 2016

In this paper we study the change of the Willmore energy of curves, as a
special case of so-called Helfrich energy, under infinitesimal bending
determined by the stationarity of arc length. We examine the variation of the
unit tangent, principal normal and binormal vector fields, the curvature and
the torsion of the curve. We obtain an explicit formula for calculating the
variation of the Willmore energy, as well as the Euler-Lagrange equations
describing equilibrium. We find an infinitesimal bending field for a helix
and compute the variation of its Willmore energy under such infinitesimal
bending.
Overview and comparative analysis of the properties of the Hodge-de Rham and Tachibana operators
Authors: Stepanov S.E. , Tsyganok I.I. , Mikes J.
Published: January 2016

In the present paper we consider two natural, elliptic, self-adjoint second
order di_erential operators acting on exterior differential forms on
Riemannian manifolds. These operators are the wellknown Hodge-de Rham and
little-known Tachibana operators. Basic properties of these operators are
very similar, or vice versa are dual with respect to each other. We review
the results (partly obtained by the authors) on the geometry of these
operators and demonstrate the comparative analysis of their properties.
Form-finding software and minimal surface equation: A comparative approach
Authors: Lipkovski Jana , Lipkovski Aleksandar
Published: January 2016

The shape of membrane and cable-net structures is usually modeled by geometry
of minimal surfaces. Using central finite differences method, a nonlinear
iterative process for finding the minimal surface with given fixed boundary
conditions is developed and implemented in Mathematica?. Having in mind
form-finding of membrane structures, the results are compared with the
results obtained by commercial package EASY?, made by Technet GmbH, Germany.
Binary to RNS encoder for the moduli set {2n-1, 2n, 2n+1} with embedded diminished-1 channel for DSP application
Authors: Krstic Ivan , Stamenkovic Negovan , Stojanovic Vidosav
Published: January 2016

A binary-to-residues encoder (forward encoder) is an essential building block
for the residue number system digital signal processing (RNS DSP) and as such
it should be built with a minimal amount of hardware and be efficient in
terms of speed and power. The main parts of the forward encoder are residue
generators which are usually classified into two categories: the one based on
arbitrary moduli-set which make use of look-up tables, and the other based on
the special moduli sets. A new memory less architecture of binary-to-RNS
encoder based on the special moduli set {2n?1,2n,2n+1} with embedded modulo
2n+1 channel in the diminished-1 representation is presented. Any of two
channels (standard modulo 2n +1, or modulo 2n+1 in the diminished-1
representation) operation can be performed by using a single switch. The
proposed encoder has been implemented on a Xilinx FPGA chip for the various
dynamic range requirements.
3-D stereoscopic modeling of the Tesla’s Long Island
Authors: Vuckovic Vladan , Spasic Sanja
Published: January 2016

paper presents in detail the methods for realization of the basic software
infrastructure for the conversion of 3-D animation of Tesla?s laboratory in
Long Island to modern stereoscopic 3-D formats. Modeling of Tesla?s lab is
done in cooperation with the Nikola Tesla Museum in Belgrade on a project
entitled ?Computer Simulation and Modeling of the Original Patents of Nikola
Tesla? approved by the Ministry of Education and Science of the Republic of
Serbia. In recent years, there has been a revolution in the field of 3-D
technology, so it is clear that this will be the strategic direction of the
progressing of television, cinema screenings and presentations in the future.
Using modern technology for generating and conversion to stereoscopic 3-D
format, the authors show in detail the procedure that was used in the
realization of this segment of the project. The complete improved 3D
developing pipeline from the original photograph to the stereoscopic 3D
real-time model is also presented. The novelty in the phase of semi-automatic
materialization of the wire models is also described.
The implementation of signal analysis in java to determine the sound of human voice and its graphical representation in standard music notation
Authors: Solecki Patryk , Zabierowski Wojciech
Published: January 2016

The article presents the problems associated with signal processing in the
human voice analysis. Based on the specific implementation of algorithms
defining the human voice pitch, paper is shows the result in the form of a
standard music notation with treble and bass keys on the stave. Particular
attention is paid to the performance of the algorithms used for their
implementation in Java. The Basic analysis of human voice signals is not a
challenge, in general, but its implementation on mobile devices like
smartphones with their limited hardware resources remains a challenge. The
limitations of both, the CPU and the memory, affect the processing speed of
the Java virtual machine. One should remember that the quality of microphone
used in this type of mobile devices is low. From this point of view we have
presented the new approach to the well-known problem of signal analysis
implemented in computer applications such as Raven.
Spatial extent in demographic research - approach and problems
Authors: Knezevic Aleksandar , Vojkovic Gordana
Published: January 2016

One of the starting methodological problems in demographic research is the
definition of spatial extent, which mostly doesn?t correspond to spatial
extent already defined by different levels of administrative-territorial
unitsthat are used for distribution of usable statistical data. That?s why
determining the spatial extent of a demographic research is closely tied with
administrative-territorial division of the territory that is being
researched, wherein the fact that differentiation of demographic phenomena
and processes cannot be the only basis of setting the principles of
regionalization must be strictly acknowledged. This problem is particularly
common in historical demographic analyses of geographically determined
wholes, which are in administratively-territorial sense represented by one or
more smaller territorial units, with their borders changing through the
history, which directly affects comparability of the statistical data, and
makes it considerably more difficult to track demographic change through
longer time intervals. The result of these efforts is usually a solution
based on a compromise which enables us to examine the dynamics of population
change with little deviation from already defined borders of
regional geographic wholes. For that reason in this paper the problem of
defining spatial extent in demographic research is examined trough several
different approaches in case of Eastern Serbia, as a geographically
determined region, a historic area, a spatially functioning whole and as a
statistical unit for demographic research, with no judgment calls in regard
to any of the regionalization principles.
Effects of deficit irrigation on grain yield and ear characteristics of maize
Authors: Kresovic Branka , Gajic Bosko , Tapanarova Angelina , Pejic Borivoj , Tomic Zorica , Vujovic Dragan , Zivotic Ljubomir
Published: January 2016

In the Vojvodina region, drought is an important factor limiting grain yield
in maize. The aims of this research were to compare irrigation scheduling in
maize (cv. ZP SC 684), and to evaluate grain yield and ear characteristics.
A 3-year field experiment was carried out in the Vojvodina region, a
northern part of the Republic of Serbia (384 mm of rainfall in the
maize-growing period). Maize was subjected to four irrigation levels
(rainfed - I0 and supply at 80-85% - I1, 70-75% - I2 and 60-65% - I3 of
field capacity). The results indicated a large yearly variability, mainly
due to a rainfall event at the flowering, fertilization and grain filling
stages. A significant irrigation effect was observed for all the variables
under study, with significant differences between the three irrigation
treatments. The grain yield ranged between 8.73 and 16.33 t ha-1. The
highest grain yield of maize (average of 15.08 t ha-1) was in the I1
treatment, while the non-irrigated (I0) treatment had the lowest yield
(average of 10.20 t ha-1), a 35% grain yield reduction. With the decrease of
irrigation water, the grain yield of maize decreased. The most distinctive
impact the irrigation had on maize yield was during the warm and very dry
growth period of the year of 2008. Maize in the Vojvodina region can be
cultivated with acceptable yields while saving irrigation water and
maximizing resource-use efficiency.
Characteristics of one-year-old shoots of peach hybrids from the crossing combination Flaminia × Hale Tardiva Spadoni
Authors: Radovic Aleksandar , Nikolic Dragan , Rakonjac Vera , Bakic Ivana
Published: January 2016

The results of two-year research (2011-2012) of the most important
morphological characteristics of 1-year-old shoots in eight peach hybrids
obtained from a crossing combination Flaminia ? Hale Tardiva Spadoni were
shown in this paper. The following characteristics were studied in tested
hybrids: length and diameter of shoots, internode length, number of flowers
and vegetative buds per shoot, ratio of flower to vegetative buds, number of
flower buds per node and 1-m length of a shoot. The properties of sylleptic
shoots on one-year-old shoots have also been studied. The significant
differences were determined among the hybrids for parameters such as the
diameter of shoots, internode length, number of flower and vegetative buds
per shoot. Hybrids FH1 and FH6 were characterized by the highest density of
flower buds, so that they are singled out as potentially the most yielding.
These hybrids may be of interest for growing in areas where there is a risk
of frost and in the domain of breeding when creating new peach cultivars of
high yield potential.
Humification degree of Rendzina soil humic acids influenced by carbonate leaching and land use
Authors: Radmanovic Svjetlana , Djordjevic Aleksandar , Nikolic Natasa
Published: January 2016

The humification degrees of humic acids extracted from calcareous and
decarbonated Rendzinas under different land use were characterized upon their
optical properties, to evaluate the influence of carbonate leaching
(decarbonation) and different land uses. Decarbonation influenced the
humification degree of humic acids positively. Base leaching and
acidification of decarbonated Rendzinas led to a decrease in humification
degree of humic acids. In calcareous Rendzinas, the humification degree of
humic acids was in descending order: grassland>arable land>forest land, and
in decarbonated Rendzinas: arable land>grassland>forest land. The
humification degree of humic acids was higher in the calcareous forest and
grassland Rendzinas compared to decarbonated Rendzinas, analogously in
decarbonated arable land compared to calcareous arable land Rendzinas.
Differences in the humification degree of humic acids among various land uses
that emerged between calcareous and decarbonated Rendzinas indicate the
dominant influence of soil chemical characteristics (carbonate content and pH
value) compared with the quantity and quality of the organic litter input.
Peel and leaf powders of three fruits and a vegetable as promising botanicals against Callosobruchus maculatus (F.)
Authors: Musa Abdulrasak , Adewale Samuel
Published: January 2016

The aim of this study was to examine the insecticidal activities of powders
of bitter leaf, cashew leaf, orange peel and pawpaw leaf against
Callosobruchus maculatus (F.) (Coleoptera: Bruchidae). These were tested at
2.5%, 5.0% and 7.5% (w/w) for their insecticidal activities against the
insect. Results showed that the ovicidal and adulticidal activities of the
plant powders depended on dosages and exposure time. Mortalities of 16.28%
and 18.75% were observed in bitter leaf powder applied at 7.5% (w/w) dosage
within 24 and 48 hours post infestation (HPI), respectively. In grains
treated with 7.5% orange peel powder, 12.50% and 16.28% mortalities were
observed within 24 and 48 HPI, respectively. Each of bitter leaf and orange
peel powders was significantly different (p<0.05) in causing adult mortality
at the highest dosage compared with the control. Oviposition was inhibited at
the highest dosage of the plant powders, but the percentage of oviposition in
the lower dosages was three-fold lower than the control. The plant powders
also significantly reduced progeny emergence and grain damaged by the beetle.
No beetle emergence was recorded in grains treated with bitter leaf powder at
27 DPI. Adult beetles in grains treated with cashew and pawpaw leaf powders
caused grain damage of 46.3-54.7% and 44.7-60.7%, respectively during the
study period. There was a noteworthy decrease in insecticidal effects of the
plant powders as indicated: bitter leaf > orange peel > cashew leaf > pawpaw
leaf. It is recommended that incorporating these plant parts in pest
management of stored products will guarantee user safety, reduce
environmental pollution and suppress insect infestation.
Determining the physiochemical changes and time of chilling injury incidence during cold storage of pomegranate fruit
Authors: Taghipour Leila , Rahemi Majid , Assar Pedram
Published: January 2016

Intermittent warming (IW) is a good postharvest technique to prevent or
alleviate chilling injuries during cold storage. Performing the warming
treatment at the period of time before chilling injury is irreversible during
storage, and it is the first prerequisite for a successful IW treatment. In
order to determine the fruit physiochemical changes and time of irreversible
chilling injury incidence during cold storage of pomegranate fruit (cv.
Rabab-e-Neyriz), this research was conducted. Fruits were stored at 2 ? 0.5?C
and 90 ? 5% relative humidity for 90 days. At 15-day intervals, 40 fruits
(four replicates and 10 fruits in each replicate) were sampled and further
stored at 20?C for 3 days (shelf life). Chilling injury (CI) index and weight
loss (WL) in intact fruits, electrolyte leakage (EL) and K leakage (KL) in
peel samples, total soluble solids (TSS), titratable acidity (TA), TSS/TA
ratio and pH in fruit juice were measured. With respect to quality
parameters, TSS did not change significantly under cold storage. According to
TA changes, the TSS/TA ratio was decreased up to 30 days but subsequently
increased and the highest ratio was detected at the end of storage, which was
significantly higher than the TSS/TA ratio at the harvest time. Results
related to CI index, WL, EL and KL showed that pomegranate fruits could be
stored cold without significant chilling damages up to 30 days. It was
suggested that performing the IW treatment during this period could be
concomitant with desired effects in long-term storage of this commercial
cultivar.
Effect of the phase change material in a solar receiver on thermal performance of parabolic dish collector
Authors: Senthil Ramalingam , Cheralathan Marimuthu
Published: January 2016

In this work, the use of phase change material in the circular tank solar receiver is proposed for a 16 m2 Scheffler parabolic dish solar concentrator to improve the heat transfer in the receiver. Magnesium chloride hexahydrate with melting temperature of 117?C is selected as the phase change material in the annular space of the receiver with rectangular fins inside the phase change material. Experimental work is carried out to analyze heat transfer from the receiver to heat transfer fluid with and without phase change material in the inner periphery. Energy and exergy efficiency are determined from the measurements of solar radiation intensity, receiver temperature, surroundings temperature, heat transfer fluid inlet and outlet temperatures, storage tank temperature, and wind speed. The experiments were conducted in SRM University, Chennai, India (latitude: 13? 5? N, longitude: 80?16? E) in April 2014. Use of phase change material in receiver periphery increased energy efficiency by 5.62%, exergy efficiency by 12.8% and decreased time to reach the boiling point of water by 20% when compared with the receiver without phase change material.
The features of heterogeneous water droplet evaporation in high-temperature combustion products of typical flammable liquids
Authors: Piskunov Maxim , Strizhak Pavel , Volkov Roman , Zhdanova Alena
Published: January 2016

This paper presents the experimental results on heating and evaporation features of heterogeneous (with opaque solid particles ? the size of 0.05-0.5 mm, relative mass concentration 0-1%) water droplets (the initial size ? radius 1-3 mm) during their motion through high-temperature (500-1800 K) gases. A significant increase in the integral characteristics of evaporation by introducing opaque inclusions into droplets was observed. The influence of energy accumulation on the conditions of droplet evaporation at the internal solid/liquid interfaces was established. For proportioned inclusions, the conditions of intensive vaporization (leading to the explosive disintegration of droplets) at internal inclusion/liquid interfaces was set. To summarize research results, experiments were conducted with the combustion products of kerosene, gasoline, industrial alcohol, acetone, and oil. The particles of graphite, carbon, and aluminum as solid inclusions were used. The investigation compared integral characteristics of heterogeneous droplet evaporation under the conditions of non-stationary (gas temperature varied from 1800 K to 500 K over the length of channel) and nearly stationary (gas temperature was maintained at about 1100 K) heating.
Exergy analysis of a vacuum tube solar collector system having indirect working principle
Authors: Yildizhan Hasan , Sivrioglu Mecit
Published: January 2016

In this study, the energy and exergy analysis of a hot water preparation system, which is a boiler assisted vacuum tube solar collector, has been conducted. The obtained data were compared with reported results in the literature related to direct operating principle system. Average energy and exergy efficiencies of the experimental system were founded 12% and 0.3%, respectively. The average energy and exergy efficiencies of the vacuum tube solar collectors were founded 13.6% and 1.3%. Energy and exergy efficiencies of the vacuum tube solar collectors, which have indirect operating principle, are lower than direct system working with solar collectors. Maximum exergy loss has occurred in the vacuum tube solar collectors and followed it boiler and pump, respectively.
The numerical and experimental study of two passes power plant condenser
Authors: Rusowicz Artur , Laskowski Rafał , Grzebielec Andrzej
Published: January 2016

The steam condenser is one of the most important element in whole power plant
installation. Their proper design and operation makes a significant
contribution to the efficiency of electricity production. The purpose of this
article is to propose a two-dimensional mathematical model that allows
modeling condenser work. In the model, the tube bundle is treated as a porous
bed. The analysis has been subjected to a two passes power condenser with a
capacity of 50 MW. The mathematical analysis was compared with the results of
experimental studies. The average error between the model and the experiment
for difference of cooling water temperatures was 5.15% and 11.60% for the
first and second pass respectively. This allows to conclude that the proposed
model is good enough to optimize future work of the condenser.
A computational study of heat transfer under twin turbulent slot jets impinging on planar smooth and rough surfaces
Authors: Xu Peng , Sasmito Agus , Mujumdar Arun
Published: January 2016

The flow and heat transfer characteristics of twin turbulent slot jets
impinging on planar smooth and rough surfaces are examined using a
computational fluid dynamics model. The interaction between jets lowers the
heat transfer performance of each jet in the zone where the wall jets
collide. A single jet performs better than the equivalent twin jet. The
average heat transfer under twin jets which are injected alternately so that
each one of the pair of jets behaves like a single jet, is found to be better
than twin jets issuing simultaneously. It is proposed that alternating jet
flows in the twin jet arrangement is a simple novel way to enhance thermal
performance of jet pairs. Along with parametric studies of the key flow and
geometric parameters, effects of large temperature differences between the
jet air and the target surface being heated, and model roughness of the
target surface are also evaluated. Interestingly, roughness can lower the
heat transfer performance in the impingement zone as the fluid can get
trapped in the valleys in the rough surface.
Long-term predictions of the energy development - possibilities and challenges
Authors: Kanevce Gligor , Dedinec Aleksandar , Dedinec Aleksandra , Kanevce Ljubica
Published: January 2016

In this paper the possibilities, disadvantages and benefits of long-term
planning of energy development, are analysed. The factors influencing the
development of energy and the factors influencing the accuracy of forecasting
of the future development of energy are presented. The uncertainties that
make the differences in modelling on a global scale, as well as the
uncertainties that make the differences in modelling of the energy
development of the Republic of Macedonia are also presented. Sensitivity
analysis of the influence of different factors on the development of energy
in the Republic of Macedonia was carried out. For those purposes the energy
development of the Republic of Macedonia for the period up to 2035 year is
calculated by using MARKAL model. The main features of the MARKAL model are
also presented.
Non-commutative finite monoids of a given order n ≥ 4
Authors: Ahmadi B. , Campbell C.M. , Doostie H.
Published: January 2016

For a given integer

n
=

p
1

α
1

p
2

α
2

⋯

p
k

α
k

$n = p_1^{\alpha _1 } p_2^{\alpha _2 } \cdots p_k^{\alpha _k }$

(k ≥ 2), we give here a class of finitely presented finite monoids of order n. Indeed the monoids Mon(π), where

π
=

〈

a
1

,

a
2

,
…
,

a
k

|

a
i

p
i

α
i

=

a
i

,
 
(

i
=
1
,
2
,
…
,
k

)

,

a
i

a

i
+
1

=

a
i

,
 

(

i
=
1
,
2
,
…
,
k
−
1

)

〉

.

$$\pi = {\langle {a_1 ,a_2 , \ldots ,a_k |a_i^{p_i^{\alpha _i } } = {a_i}, {\left({i = 1,2, \ldots ,k} \right)}, a_i a_{i + 1} = {a_i}, \left({i = 1,2, \ldots ,k - 1} \right)} \rangle} .$$

As a result of this study we are able to classify a wide family of the k-generated p-monoids (finite monoids of order a power of a prime p). An interesting di erence between the center of finite p-groups and the center of finite p-monoids has been achieved as well. All of these monoids are regular and non-commutative.
Determinant Identities and the Geometry of Lines and Circles
Authors: Anghel Nicolae
Published: January 2016

The focus of this note is the nontrivial determinant identities which typically underlie the complex analytic proofs of all the results in the plane geometry of lines and circles. After setting up a basic dictionary relating lines and circles to complex determinants we derive such identities in connection with four geometry problems: the Steiner line, a variant of Euler’s nine-point circle, the Johnson-Tzitzeica circles, and an extension of a certain geometry problem, proposed at the 52nd International Mathematical Olympiad, Amsterdam 2011.
A Krull-Schmdit type theorem for coherent sheaves
Authors: Argáez A. S.
Published: January 2016

Let X be projective variety over an algebraically closed field k and G be a finite group with g.c.d.(char(k), |G|) = 1. We prove that any representations of G on a coherent sheaf, ρ : G → End(ℰ), has a natural decomposition ℰ ≃ ⊕ V ⊗
k
ℱ
V
, where G acts trivially on ℱ
V
and the sum run over all irreducible representations of G over k.
Some remarks on limit mixed Hodge structures and spectrum
Authors: Dimca Alexandru , Saito Morihiko
Published: January 2016

In this note we clarify some subtle points on the limit mixed Hodge structures and on the spectrum. These are more or less well-known to the specialists, but do not seem to be stated explicitly in the literature. However, as they do not seem to be obvious to the beginners, we consider them to be worth writing down explicitly. The general constructions are exemplified by considering the isolated (weighted) homogeneous singularities in detail.
On the torsion group of elliptic curves induced by D(4)-triples
Authors: Dujella Andrej , Mikić Miljen
Published: January 2016

A D(4)-m-tuple is a set of m integers such that the product of any two of them increased by 4 is a perfect square. A problem of extendibility of D(4)-m-tuples is closely connected with the properties of elliptic curves associated with them. In this paper we prove that the torsion group of an elliptic curve associated with a D(4)-triple can be either ℤ/2ℤ × ℤ/2ℤ or ℤ/2ℤ × ℤ/6ℤ, except for the D(4)-triple {−1, 3, 4} when the torsion group is ℤ/2ℤ × ℤ/4ℤ.
Characterization of Speherical Helices in Euclidean 3-Space
Authors: Ekmekci Nejat , Okuyucu O. Zeki , Yayli Yusuf
Published: January 2016

In this paper, we calculate Frenet frames of the tangent indicatrix (t), principal normal indicatrix (n) and binormal indicatrix (b) of the curve α in ℝ3 which are spherical curves. Also, we give some differential equations which are characterizations for (t), (n) and (b) to be general helix. Morever we give a characterization for tangent indicatrix (t) to be a circle.
On The Solvability In Local Extensions
Authors: Lbekkouri Akram
Published: January 2016

The aim of this paper is the study of the solvability of finite extensions of local fields in the general case that is when the residue field is not necessarily perfect.
Reflection and transmission of waves from imperfect boundary between two heat conducting micropolar thermoelastic solids
Authors: Sharma Kunal , Marin Marin
Published: January 2016

The problem of reflection and transmission of plane waves at an imperfect boundary between two thermally conducting micropolar elastic solid half spaces with two temperature is investigated. Amplitude ratio of various reflected and transmitted waves are presented when a set of coupled longitudinal wave (LD-wave) and thermal wave (T-wave) and a set of coupled transverse wave and microrotation waves (CDI, CDII) is made incident. The expressions for reflection and transmission coefficients which are the ratios of the amplitudes of reflected and transmitted waves at different angles of incident wave are obtained. The corresponding expressions for the normal force stiffness, transverse force stiffness, transverse couple stiffness and perfect bonding has also been included. Stiffness and two temperature e ects on these amplitude ratios with angle of incidence have been depicted graphically. Some special and particular cases are also discussed.
A multivalued version of Krasnoselskii’s theorem in generalized Banach spaces
Authors: Petre Ioan-Radu
Published: January 2016

The purpose of this paper is to extend Krasnoselskii’s fixed point theorem to the case of generalized Banach spaces for multivalued operators. As application, we will give an existence result for a system of Fredholm-Volterra type differential inclusions.
Numerical Decomposition of Affine Algebraic Varieties
Authors: Rashed Shawki AL , Pfister Gerhard
Published: January 2016

An irreducible algebraic decomposition

∪

i
=
0

d

X
i

=

∪

i
=
0

d

(

∪

j
=
1

d
i

X
ij

)

$ \cup _{i = 0}^d X_i = \cup _{i = 0}^d ({\cup _{j = 1}^{d_i } X_{ij} } )$

of an affine algebraic variety X can be represented as a union of finite disjoint sets

∪

i
=
0

d

W
i

=

∪

i
=
0

d

(

∪

j
=
1

d
i

W
ij

)

$\cup _{i = 0}^d W_i = \cup _{i = 0}^d ({\cup _{j = 1}^{d_i } W_{ij} } )$

called numerical irreducible decomposition (cf. [14],[15],[18],[19],[20],[22],[23],[24]). The Wi
correspond to the pure i-dimensional components Xi
, and the Wij
present the i-dimensional irreducible components Xij
. The numerical irreducible decomposition is implemented in Bertini (cf. [3]). The algorithms use homotopy continuation methods. We modify this concept using partially Gröbner bases, triangular sets, local dimension, and the so-called zero sum relation. We present in this paper the corresponding algorithms and their implementations in Singular (cf. [8]). We give some examples and timings, which show that the modified algorithms are more efficient if the number of variables is not too large. For a large number of variables Bertini is more efficient*.
Algebraic properties of the binomial edge ideal of a complete bipartite graph
Authors: Schenzel Peter , Zafar Sohail
Published: January 2016

Let JG
denote the binomial edge ideal of a connected undirected graph on n vertices. This is the ideal generated by the binomials xiyj − xjyi, 1 ≤ i < j≤ n, in the polynomial ring S = K[x
1, . . . , xn, y
1, . . . , yn
] where {i, j} is an edge of G. We study the arithmetic properties of S/JG
for G, the complete bipartite graph. In particular we compute dimensions, depths, Castelnuovo-Mumford regularities, Hilbert functions and multiplicities of them. As main results we give an explicit description of the modules of deficiencies, the duals of local cohomology modules, and prove the purity of the minimal free resolution of S/JG
.
Extremal problems on the generalized (n, d)-equiangular system of points
Authors: Targonskii A.
Published: January 2016

The paper of Lavrent’ev [1] was the beginning of geometrical theory of functions of the complex variable. He solved a problem on the product of conformal radiuses of two non-overlapping domains. In many papers (see [2] – [13]) the Lavrent’ev’s result are generalized. In this paper are obtained the new results of this direction.
Measurement Properties of the Lower Extremity Functional Scale: A Systematic Review
Authors: Mehta Saurabh P. , Fulton Allison , Quach Cedric , Thistle Megan , Toledo Cesar , Evans Neil A.
Published: January 2016

Study Design

Systematic review of measurement properties.

Background

Many primary studies have examined the measurement properties, such as reliability, validity, and sensitivity to change, of the Lower Extremity Functional Scale (LEFS) in different clinical populations. A systematic review summarizing these properties for the LEFS may provide an important resource.

Objective

To locate and synthesize evidence on the measurement properties of the LEFS and to discuss the clinical implications of the evidence.

Methods

A literature search was conducted in 4 databases (PubMed, MEDLINE, Embase, and CINAHL), using predefined search terms. Two reviewers performed a critical appraisal of the included studies using a standardized assessment form.

Results

A total of 27 studies were included in the review, of which 18 achieved a very good to excellent methodological quality level. The LEFS scores demonstrated excellent test-retest reliability (intraclass correlation coefficients ranging between 0.85 and 0.99) and demonstrated the expected relationships with measures assessing similar constructs (Pearson correlation coefficient values of greater than 0.7). The responsiveness of the LEFS scores was excellent, as suggested by consistently high effect sizes (greater than 0.8) in patients with different lower extremity conditions. Minimal detectable change at the 90% confidence level (MDC90) for the LEFS scores varied between 8.1 and 15.3 across different reassessment intervals in a wide range of patient populations. The pooled estimate of the MDC90 was 6 points and the minimal clinically important difference was 9 points in patients with lower extremity musculoskeletal conditions, which are indicative of true change and clinically meaningful change, respectively.

Conclusion

The results of this review support the reliability, validity, and responsiveness of the LEFS scores for assessing functional impairment in a wide array of patient groups with lower extremity musculoskeletal conditions. J Orthop Sports Phys Ther 2016;46(3):200–216. Epub 26 Jan 2016. doi:10.2519/jospt.2016.6165
La Plana de Vic (Catalogne). Incidences des transformations sociales dans une société et une économie agraires
Authors: Casassas Simo Lluis
Published: January 2016

L'auteur rappelle les caractères physiques (climat et sols) de la Plana de Vie, bassin de la Catalogne intérieure, pour expliquer que l'introduction de cultures nouvelles (pomme de terre, maïs) y fut aisée et précoce entraînant l'enrichissement des propriétaires fonciers dès la fin du XVIIe siècle. Il montre que cette mutation rendit ces propriétaires plus conservateurs et les détourna de participer aux débuts de la révolution industrielle en Catalogne autant que de favoriser l'introduction d'innovations techniques ou économiques, ce qui bloqua les structures sociales à un moment où elles se transformaient assez vite dans le reste de la Catalogne. L'auteur suggère, d'une part, que seule l'intégration des groupes sociaux issus des modifications les plus récentes pourrait permettre à la comarque d'Osona de s'engager dans des transformations nouvelles, et que, d'autre part, la seule solution définitive à la stagnation de ce secteur passe par la mise en œuvre d'un plan régional multisectoriel coordonné qui rompe avec l'entraînement du modèle monocentral et industriel actuel.
Une cartographie de reconnaissance des géosystèmes dans les Andes du Pérou
Authors: Bertrand Georges , Dollfus Olivier , Hubschman Jacques
Published: January 2016

Un mapa tipo « survey » de los geosistemas del alto Chancay (vertiente pacífeea de los Andeas peruanos). Durante una breve misión incluida en un programa de investigación interdisciplinaria sobre las comunidades agrarias de la vertiente pacifica de los Andes peruanos, hemos estudiado los grandes rasgos físicos de dos pequeñas cuencas afluentes del rio Chancay. Hemos dibujado un mapa simplificado al 1/25 000, establecido con el método de estudio integrado del medio ambiente (geosistema) . Las largas pendientes de 3 500 m de desnivel (entre 1 500 y 5 000 m de cultura), caracterisados en su parte baja por la aridez y por el frío en la parte alta, se caracterizan por la potencia del gradiente vertical que empuja una cuantidad enorme de energía. Esta energia mantiene las vertientes en instabilidad y el desarollo de la agricultura y del pastoreo no la pueden parar. El mapa utilizada y comprueba el contenido ecológico de los grandes pisos montañosos andinos (yunga, quetchua, suni, puna, janea) y define las ordenaciones agrícolas y pastoriles correspondientes.
Gavage des oies et canards et production de gras dans les exploitations agricoles en polyculture de Chalosse (Landes)
Authors: Clairacq Jean
Published: January 2016

Étudié ici en Chalosse (Landes), l'engraissement par gavage des oies et des canards est une des combinaisons qui associent dans beaucoup d'exploitations du Sud-Ouest de la France productions céréalières et élevages : le maïs représente depuis son introduction un atout supplémentaire de cette combinaison qui réclame, d'autre part, une main-d'œuvre experte, laquelle demeure en majorité féminine. Après une tendance au déclin jusque vers 1970, la production de gras a repris, de nombreux chefs d'exploitation jeunes intensifiant l'engraissement des oies et développant celui des canards. Autrefois activité hivernale, le gavage tend à devenir une activité annuelle grâce à la climatisation des locaux et au succès de recherches qui permettent d'améliorer les performances et la qualité des volailles. Les effectifs gavés atteignent fréquemment un millier de têtes par exploitation. Viande et foies gras continuent d'être vendus par les éleveurs sur les marchés de détail ou, parfois, ce qui est plus nouveau, par le truchement de groupements agricoles, à des conserveries industrielles. La production artisanale du gras caractérise en Chalosse des exploitations agricoles familiales d'une SAU de 10 à 15 ha dont les autres productions ne peuvent guère être intensifiées : cet élevage représente pour la plupart d'entre elles le meilleur moyen de valoriser sur place une fraction notable de leur récolte de maïs en tirant parti de leur force de travail disponible.
Les migrations alternantes vers Toulouse. Bilan de vingt années
Authors: Coppolani Jean
Published: January 2016

Entre 1954 et 1975 les migrations de travail en direction de Toulouse ont augmenté dix fois plus que la population active de la ville et quinze fois plus que sa population totale. La croissance de la population de la banlieue proche, en partie par immigration depuis la ville, en est la cause principale, mais on assiste aussi à un élargissement des rayons de recrutement qui, avec une densité décroissante depuis le centre, s'étend à plus de 100 km de la ville et s'étire sur le grand axe du Sud-Ouest de Bordeaux à Montpellier. En outre, le transfert d'établissements toulousains, en banlieue, pendant la même période a entraîné l'apparition de migrations de la ville vers la banlieue.
Des banlieues partout... en Midi-Pyrénées
Authors: Laborie Jean-Paul
Published: January 2016

L'analyse des premiers résultats du recensement de 1982, comparés à l'évolution de la période intercensale précédente, permet à l'auteur de souligner que l'arrêt ou le ralentissement de la croissance de la population de villes s'accompagne en Midi-Pyrénées d'une diffusion de la banlieue à tous les échelons urbains existant : la banlieue est partout, ce qui est peut être le signe que la société et les institutions tentent d'esquiver les coûts de l'urbanisation.
Des données provisoires aux tendances profondes : la population de l'Aquitaine en 1982
Authors: Pailhé Joël
Published: January 2016

Crecimiento y evolución de la población de Aquitania. Por primera vez, desde hace un siglo, la población de Aquitania ha alcanzado un crecimiento superior al promedio francés. El proseguimiento de la inmigración explica lo esencial de dicho crecimiento. El área de los aumentos de población va extendiéndose a las zonas rurales cercanas a las ciudades, mientras que las pérdidas alcanzan las partes centrales de las ciudades y los sectores rurales « profundos » más desfavorecidos. Correspondiendo su análisis a un período de crisis (1975- 1982), tal evolución de la población no puede ser considerada como el signo de una tendencia valedera para un término largo.
Base metal-catalyzed benzylic oxidation of (aryl)(heteroaryl)methanes with molecular oxygen
Authors: Sterckx Hans , De Houwer Johan , Mensch Carl , Herrebout Wouter , Tehrani Kourosch Abbaspour , Maes Bert U W
Published: January 2016

The methylene group of various substituted 2- and 4-benzylpyridines, benzyldiazines and benzyl(iso)quinolines was successfully oxidized to the corresponding benzylic ketones using a copper or iron catalyst and molecular oxygen as the stoichiometric oxidant. Application of the protocol in API synthesis is exemplified by the alternative synthesis of a precursor to the antimalarial drug Mefloquine. The oxidation method can also be used to prepare metabolites of APIs which is illustrated for the natural product papaverine. ICP–MS analysis of the purified reaction products revealed that the base metal impurity was well below the regulatory limit.
COMPARISON OF CHAOTIC AND FRACTAL PROPERTIES OF POLAR FACULAE WITH SUNSPOT ACTIVITY
Authors: Deng L. H. , Li B. , Xiang Y. Y. , Dun G. T.
Published: January 2016

The solar magnetic activity is governed by a complex dynamo mechanism and exhibits a nonlinear dissipation behavior in nature. The chaotic and fractal properties of solar time series are of great importance to understanding the solar dynamo actions, especially with regard to the nonlinear dynamo theories. In the present work, several nonlinear analysis approaches are proposed to investigate the nonlinear dynamical behavior of the polar faculae and sunspot activity for the time interval from 1951 August to 1998 December. The following prominent results are found: (1) both the high- and the low-latitude solar activity are governed by a three-dimensional chaotic attractor, and the chaotic behavior of polar faculae is the most complex, followed by that of the sunspot areas, and then the sunspot numbers; (2) both the high- and low-latitude solar activity exhibit a high degree of persistent behavior, and their fractal nature is due to such long-range correlation; (3) the solar magnetic activity cycle is predictable in nature, but the high-accuracy prediction should only be done for short- to mid-term due to its intrinsically dynamical complexity. With the help of the Babcock–Leighton dynamo model, we suggest that the nonlinear coupling of the polar magnetic fields with strong active-region fields exhibits a complex manner, causing the statistical similarities and differences between the polar faculae and the sunspot-related indicators.