bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnosis of botulism types C and D in cattle by a monoclonal antibody‐based sandwich ELISA
Authors: Brooks C. E. , Clarke H. J. , Graham D. A. , Ball H. J.
Published: April 2011

This study was undertaken to evaluate two monoclonal antibody‐based sandwich ELISAs (sELISAs) for the detection of Clostridium botulinum neurotoxins (BoNTs) types C and D from culture‐enriched intestinal content samples from cattle. To validate the diagnostic significance of the presence of cultivable, toxin‐producing C botulinum in the intestines of cattle, samples from both suspect and non‐suspect botulism cases were examined. BoNT was detected by both sELISAs in a greater number of suspect animals than by direct testing of uncultured samples by mouse bioassay. One sELISA detected two BoNT C and one BoNT Group III mosaic isoform in three animals that were missed by the other, and both sELISAs failed to identify samples from two mouse bioassay‐positive BoNT C animals. BoNT D was also detected in one non‐suspect sample by one of the sELISAs.
ACTIVE AND PASSIVE DEFENSE AGAINST MULTIPLE ATTACK FACILITIES
Authors: LEVITIN GREGORY , HAUSKEN KJELL , BEN-HAIM HANOCH
Published: April 2011

The paper considers a situation when a terrorist with N attack facilities allocates its resource between attacking an object and protecting the facilities that will be used in the attack. A government allocates its resource between protecting the object passively and striking actively and preventively against all or a subset of the attack facilities. The government strikes preventively if the object destruction probability is lower than when choosing passive defense. The paper formulates a zero-sum situation in which the terrorist chooses how to distribute its resource between the attack and protection efforts where the government chooses how to distribute its resource between the (PS) preventive strike and protection efforts and decides how many facilities to strike. It is shown that independently of the number of facilities the government strikes, the sum of the fraction of the terrorist's resource allocated to attack and the fraction of the government's resource allocated to the PS always equals one. The condition of the PS effectiveness is formulated. Examples are provided to illustrate the methodology of the model analysis.
A NOVEL RECURRENT NEURAL NETWORK FOR SOLVING MLCPs AND ITS APPLICATION TO LINEAR AND QUADRATIC PROGRAMMING PROBLEMS
Authors: EFFATI SOHRAB , GHOMASHI ABBAS , ABBASI MASUMEH
Published: April 2011

In this paper, we present a recurrent neural network for solving mixed linear complementarity problems (MLCPs) with positive semi-definite matrices. The proposed neural network is derived based on an NCP function and has a low complexity respect to the other existing models. In theoretical and numerical aspects, global convergence of the proposed neural network is proved. As an application, we show that the proposed neural network can be used to solve linear and convex quadratic programming problems. The validity and transient behavior of the proposed neural network are demonstrated by using five numerical examples.
OPTIMAL DESIGN OF A MULTI-STATE WEIGHTED SERIES-PARALLEL SYSTEM USING PHYSICAL PROGRAMMING AND GENETIC ALGORITHMS
Authors: LI WEI , ZUO MING J. , MOGHADDASS RAMIN
Published: April 2011

In this paper, we report a study of the reliability optimal design of multi-state weighted series-parallel systems. Such a system and its components are capable of assuming a whole range of levels of performance, varying from perfect functioning to complete failure. There is a component utility corresponding to each component state. This system model is more general than the traditional binary series-parallel system model. The so-called component selection reliability optimal design problem which involves selection of components with known reliability characteristics and cost characteristics has been widely studied. However, the problem of determining system cost and system utility based on the relationships between component reliability, cost and utility has not been adequately addressed. We call it optimal component design reliability problem which has been studied in one of our former papers and continued in this paper for the multi-state weighted series-parallel systems. Furthermore, comparing to the traditional single-objective optimization model, the optimization model we proposed in this paper is a multi-objective optimization model which is used to maximize expected system performance utility and system reliability while minimizing investment system cost simultaneously. Genetic algorithm is used to solve the proposed physical programming based optimization model. An example is used to illustrate the flexibility and effectiveness of the proposed approach over the single-objective optimization method.
KALUZA–KLEIN COSMOLOGICAL MODELS WITH ANISOTROPIC DARK ENERGY
Authors: ADHAV K. S. , BANSOD A. S. , WANKHADE R. P. , AJMIRE H. G.
Published: April 2011

The exact solutions of the Einstein field equations for dark energy in Kaluza–Klein metric under the assumption on the anisotropy of the fluid are obtained by applying the law of variation of Hubble parameter which yields the constant value of deceleration parameter. The isotropy of the fluid, space and expansion are examined.
NEW AGEGRAPHIC CHAPLYGIN GAS MODEL WITH VISCOSITY
Authors: WANG LEI , WU YA-BO , LI LEI , GAO YUAN , GAO JIAN
Published: April 2011

In this paper, motivated by Ref. 31, we study the so-called new agegraphic Chaplygin gas model with viscosity. Concretely, we establish the correspondence between the interacting new agegraphic dark energy (NADE) and variable generalized Chaplygin gas (VGCG) models in non-flat universe on the basis of reviewing related contents for the NADE and VGCG models. Furthermore, we reconstruct the potential of the new agegraphic scalar field as well as the dynamics of the scalar field according to the evolution of the agegraphic dark energy. Finally, we generalize our study to the case of NADE with viscosity, which includes the case without viscosity (ν = 0) as a special case.
MOMENTUM SPACE REGULARIZATIONS AND THE INDETERMINACY IN THE SCHWINGER MODEL
Authors: MORAIS C. W. , MOTA A. L.
Published: April 2011

We revisited the problem of the presence of finite indeterminacies that appear in the calculations of a Quantum Field Theory. We investigate the occurrence of undetermined mathematical quantities in the evaluation of the Schwinger model in several regularization scenarios. We show that the undetermined character of the divergent part of the vacuum polarization tensor of the model, introduced as an ansatz in previous works, can be obtained mathematically if one introduces a set of two parameters in the evaluation of these quantities. The formal mathematical properties of this tensor and their violations are discussed. The analysis is carried out in both analytical and sharp cutoff regularization procedures. We also show how the Pauli–Villars regularization scheme eliminates the indeterminacy, giving a gauge invariant result in the vector Schwinger model.
LATERAL PHASE SEPARATION OF CONFINED MEMBRANES
Authors: ASFAW MESFIN
Published: April 2011

We consider the membranes interacting via short, intermediate and long stickers. The effects of the intermediate stickers on the lateral phase separation of the membranes are studied via mean-field approximation. The critical potential depth of the stickers increases in the presence of the intermediate sticker. The lateral phase separation of the membrane is thus suppressed by the intermediate stickers. Considering the membranes interacting with short and long stickers, the effect of confinement on the phase behavior of the membranes is also investigated analytically.
THE EFFECT OF A VARYING MAGNETIC FIELD ON THE DIRAC FERMION SPECTRUM OF GRAPHENE
Authors: SETARE M. R. , JAHANI D.
Published: April 2011

We examine the effect of a magnetic field that varies inversely as the square of distance on the Dirac fermion spectrum of graphene, a single layer of graphite. We find that unlike the case of the uniform magnetic field for which zero-energy modes exhibit half the degeneracy of the other levels in the energy spectrum, the ground state in this case, as well as the other energy levels, is doubly degenerate. We also get zero-energy solutions for the special case of ky = 0.
A NOVEL REGISTER-BINDING APPROACH TO REDUCE SPURIOUS SWITCHING ACTIVITY IN HIGH-LEVEL SYNTHESIS
Authors: ELAARAJ ELIE , OUAISS IYAD
Published: April 2011

Optimizing area and timing have long been considered to be the main design challenges in high-level synthesis. A lot of research has been conducted in this area and many techniques to improve performance have been suggested. However, as design applications become more power-sensitive, and with the emergence of portable devices that operate under stringent power constraints, power consumption surfaced as a major issue to be considered in the design and optimization processes. This work studies the effects of binding and scheduling on power consumption in high-level synthesis by analyzing unnecessary switching. The major contribution of this work is to reduce the unnecessary switching at the inputs of a circuit's functional units, referred to as spurious switching activities. For this purpose, all spurious and nonspurious switching inputs in a circuit were identified, and many techniques were studied to find the optimal register bindings without inducing any increase in the number of storage elements. Power reduction was attained through altering register bindings using a cool-down simulated annealing approach. To test these techniques, a high-level synthesis environment, "Eridanus", was developed and several benchmarks, consisting of various complexities, have been tested. Using the approach suggested in this work, spurious switching activity was reduced by 40% on average.
ROLES OF CHAOTIC SADDLE AND BASIN OF ATTRACTION IN BIFURCATION AND CRISIS ANALYSIS
Authors: ZHANG YING , ROSSETTO BRUNO , XU WEI , YUE XIAOLE , FANG TONG
Published: April 2011

This paper is devoted to the dynamical behavior of a parametrically driven double-well Duffing (PDWD) system. Despite the invariant property of symmetry, this simple model exhibits a large diversity of patterns which can be observed in different situations. The transitions between symmetric forms of system responses often lead to bifurcation or crisis and complicated behaviors, such as the coexistence of different kinds of attractors. The bifurcations and crises are discussed, especially those inside the main periodic window. In particular, the role of chaotic saddles and their intrinsic links with the basin of attraction and transient chaos is studied.
DISCRETE SYMMETRY AND STABILITY IN HAMILTONIAN DYNAMICS
Authors: BOUNTIS TASSOS , CHECHIN GEORGE , SAKHNENKO VLADIMIR
Published: April 2011

In the present tutorial we address a problem with a long history, which remains of great interest to date due to its many important applications: It concerns the existence and stability of periodic and quasiperiodic orbits in N-degree of freedom Hamiltonian systems and their connection with discrete symmetries. Of primary importance in our study is what we call nonlinear normal modes (NNMs), i.e. periodic solutions which represent continuations of the system's linear normal modes in the nonlinear regime. We examine questions concerning the existence of such solutions and discuss different methods for constructing them and studying their stability under fixed and periodic boundary conditions.

In the periodic case, we find it particularly useful to approach the problem through the discrete symmetries of many models, employing group theoretical concepts to identify a special type of NNMs which we call one-dimensional "bushes". We then describe how to use linear combinations of s ≥ 2 such NNMs to construct s-dimensional bushes of quasiperiodic orbits, for a wide variety of Hamiltonian systems including particle chains, a square molecule and octahedral crystals in 1, 2 and 3 dimensions. Next, we exploit the symmetries of the linearized equations of motion about these bushes to demonstrate how they may be simplified to study the destabilization of these orbits, as a result of their interaction with NNMs not belonging to the same bush. Applying this theory to the famous Fermi Pasta Ulam (FPU) chain, we review a number of interesting results concerning the stability of NNMs and higher-dimensional bushes, which have appeared in the recent literature.

We then turn to a newly developed approach to the analytical and numerical construction of quasiperiodic orbits, which does not depend on the symmetries or boundary conditions of our system. Using this approach, we demonstrate that the well-known "paradox" of FPU recurrences may in fact be explained in terms of the exponential localization of the energies Eq of NNM's being excited at the low part of the frequency spectrum, i.e. q = 1, 2, 3, …. These results indicate that it is the stability of these low-dimensional compact manifolds called q-tori, that is related to the persistence or FPU recurrences at low energies. Finally, we discuss a novel approach to the stability of orbits of conservative systems, expressed by a spectrum of indices called GALI k, k = 2, …, 2N, by means of which one can determine accurately and efficiently the destabilization of q-tori, leading, after very long times, to the breakdown of recurrences and, ultimately, to the equipartition of energy, at high enough values of the total energy E.
ON THE OPTIMAL VACCINATION STRATEGIES FOR HORIZONTALLY AND VERTICALLY TRANSMITTED INFECTIOUS DISEASES
Authors: BUONOMO BRUNO
Published: April 2011

We consider an SEIR epidemic model for an infectious disease that spreads in the human host population through both horizontal and vertical transmission. A periodically varying contact rate is introduced to simulate recurrent outbreaks. We use the optimal control theory to assess the disease control. Optimal vaccination strategies to minimize both the disease burden and the intervention costs are analyzed. We derive the optimality system and solve it numerically. The theoretical findings are then used to simulate a vaccination campaign for rubella under several scenarios, by using epidemiological parameters obtained by real data.
SUFFICIENT TO RECOGNIZE SELF TO ATTACK NON-SELF: BLUEPRINT FOR A ONE-SIGNAL T CELL MODEL
Authors: SZABADOS TAMÁS , BAKÁCS TIBOR
Published: April 2011

Current consensus postulates that the class I-antigen processing system is evolved to present microbial antigens to specific T cells. Since such cells are rare and short-lived, they require three to five days to attain fighting strength. During this critical period he innate immune system holds back the briskly multiplying pathogens. Nevertheless, a T cell response is measurable in the lymph nodes draining the infection site within 12 to 18 h. In order to explain this paradox here we suggest a new T cell model. This is based on the observation that T cells require continuous contact of the T cell receptor (TCR) with selecting self-peptide–major histocompatibility complex (MHC) molecules in the periphery for their survival. We postulate that a dynamic steady state, a so-called coupled system is formed through low affinity complementary TCR–MHC interactions between T cells and host cells. Under such condition it is sufficient to recognize what is self in order to attack what is not self. A coupled system is regulated via soluble forms of peptide–MHC and TCR molecules by the law of mass action. In a coupled system one signal is sufficient for T cell activation. The new model implies that a significant fraction of the naive polyclonal T cells are recruited into the first line of defense from the very outset of an infection, so the number of activated T cells is increased by several orders of magnitude compared to conventional models. The one-signal model also predicts that therapeutic administration of soluble agonist or antagonist T cell receptor ligands may be able to fine tune the homeostatic physiological regulatory mechanism and thus improve the treatment of some chronic diseases such as metastatic cancer, HIV/AIDS, and transplantation.
ESTABLISHING THE WELL-BEING OF THE RURAL-URBAN ELDERLY POPULATION: A CASE STUDY OF INDONESIA
Authors: MOHD SAIDATULAKMAL , AZMAN AZLINDA , SULAIMAN JAMALLUDIN , BABA ISMAIL
Published: April 2011

This study determines and compares the influence of various demographic factors in achieving well-being of the elderly population in the rural and urban areas in Indonesia. Age, marital status, social class, perceived health and economic condition are some of the main contributing factors in measuring well-being. In addition, social aspects such as living and familial arrangement were also investigated to establish elderly population well being. Data were collected using a survey-interview method. A total of 157 elderly in the urban areas and 145 elderly in the rural areas were surveyed. A causal model of well-being was employed to analyse the data obtained. The model of well-being was then tested using path analysis to test the causal relationships among the variables. Although the study indicated that there was no significant difference of well-being between the rural and urban elderly, the social support variables generally help improve the well-being of the elderly population.
STATIONARY STOCHASTIC VISCOSITY SOLUTIONS OF SPDEs
Authors: ZHANG QI
Published: April 2011

In this paper, we construct the pathwise stationary stochastic viscosity solution of a parabolic type SPDE by backward doubly stochastic differential equation (BDSDE) on infinite horizon. For this, we study the existence, uniqueness and regularity of solutions of infinite horizon BDSDEs and their pathwise stationary property. Then by the correspondence between stochastic viscosity solutions of SPDEs and real-valued solutions of BDSDEs on infinite horizon, the stationary property is transferred from BDSDEs to SPDEs.
INTEGRAL AND COMPLETE INTEGRAL CLOSURES OF IDEALS IN INTEGRAL DOMAINS
Authors: MIMOUNI A.
Published: April 2011

This paper studies the integral and complete integral closures of an ideal in an integral domain. By definition, the integral closure of an ideal I of a domain R is the ideal given by I′ ≔ {x ∈ R | x satisfies an equation of the form xr + a1xr-1 + ⋯ + ar = 0, where ai ∈ Ii for each i ∈ {1, …, r}}, and the complete integral closure of I is the ideal Ī ≔ {x ∈ R | there exists 0 ≠ = c ∈ R such that cxn ∈ In for all n ≥ 1}. An ideal I is said to be integrally closed or complete (respectively, completely integrally closed) if I = I′ (respectively, I = Ī). We investigate the integral and complete integral closures of ideals in many different classes of integral domains and we give a new characterization of almost Dedekind domains via the complete integral closure of ideals.
THE ANNIHILATING-IDEAL GRAPH OF COMMUTATIVE RINGS II
Authors: BEHBOODI M. , RAKEEI Z.
Published: April 2011

In this paper we continue our study of annihilating-ideal graph of commutative rings, that was introduced in (The annihilating-ideal graph of commutative rings I, to appear in J. Algebra Appl.). Let R be a commutative ring with 𝔸(R) be its set of ideals with nonzero annihilator and Z(R) its set of zero divisors. The annihilating-ideal graph of R is defined as the (undirected) graph 𝔸𝔾(R) that its vertices are 𝔸(R)* = 𝔸(R)\{(0)} in which for every distinct vertices I and J, I — J is an edge if and only if IJ = (0). First, we study the diameter of 𝔸𝔾(R). A complete characterization for the possible diameter is given exclusively in terms of the ideals of R when either R is a Noetherian ring or Z(R) is not an ideal of R. Next, we study coloring of annihilating-ideal graphs. Among other results, we characterize when either χ(𝔸𝔾(R)) ≤ 2 or R is reduced and χ(𝔸𝔾(R)) ≤ ∞. Also it is shown that for each reduced ring R, χ(𝔸𝔾(R)) = cl (𝔸𝔾(R)). Moreover, if χ(𝔸𝔾(R)) is finite, then R has a finite number of minimal primes, and if n is this number, then χ(𝔸𝔾(R)) = cl (𝔸𝔾(R)) = n. Finally, we show that for a Noetherian ring R, cl (𝔸𝔾(R)) is finite if and only if for every ideal I of R with I2 = (0), I has finite number of R-submodules.
ON THE FINITENESS OF BASS NUMBERS OF LOCAL COHOMOLOGY MODULES
Authors: ABAZARI NEMAT , BAHMANPOUR KAMAL
Published: April 2011

Let R be a commutative regular ring of dimension d, I be an ideal of R and M be a non-zero finitely generated R-module. In this paper we show that Huneke's two different conjectures are equivalent. Also we provide some partially affirmative answers to them. In fact it is shown that the Bass numbers of [Formula: see text] are finite for all i ≥ 0, whenever d ≤ 3. Also if (R, m) be regular local ring, we show that the Bass numbers [Formula: see text] are finite, for all i ≥ 0 and all j ≥ 0, and [Formula: see text], for all i ≥ 0 and all j ≥ 0, whenever height(I) = 1.
ON q-SKEW ITERATED ORE EXTENSIONS SATISFYING A POLYNOMIAL IDENTITY
Authors: LEROY ANDRÉ , MATCZUK JERZY
Published: April 2011

For iterated Ore extensions satisfying a polynomial identity (PI) we present an elementary way of erasing derivations. As a consequence we recover some results obtained by Haynal. [PI degree parity in q-skew polynominal rings, J. Algebra319 (2008) 4199–4221]. We also prove that under mild assumptions on Rn = R[x1; σ1, δ1]⋯ [xn;σn;δn], the Ore extension R[x1;σ1]⋯[xn;σn] exists and is PI if Rn is PI.
WEYL GROUPS AND BASIS ELEMENTS OF HECKE ALGEBRAS OF GELFAND–GRAEV REPRESENTATIONS
Authors: RAINBOLT JULIANNE G.
Published: April 2011

The initial section of this article provides illustrative examples on two ways to construct the Weyl group of a finite group of Lie type. These examples provide the background for a comparison of the elements in the Weyl groups of GL(n, q) and U(n, q) that are used in the construction of the standard bases of the Hecke algebras of the Gelfand–Graev representations of GL(n, q) and U(n, q). Using a theorem of Steinberg, a connection between a theoretic description of bases of these Hecke algebras and a combinatorial description of these bases is provided. This leads to an algorithmic method for generating bases of the Hecke algebras of the Gelfand–Graev representations of GL(n, q) and U(n, q).
LEFT APP-RINGS OF SKEW GENERALIZED POWER SERIES
Authors: ZHAO RENYU
Published: April 2011

A ring R is called a left APP-ring if the left annihilator lR(Ra) is right s-unital as an ideal of R for any a ∈ R. Let R be a ring, (S, ≤) be a commutative strictly ordered monoid and ω: S → End (R) be a monoid homomorphism. The skew generalized power series ring [[RS, ≤, ω]] is a common generalization of (skew) polynomial rings, (skew) power series rings, (skew) Laurent polynomial rings, (skew) group rings and Malcev–Neumann Laurent series rings. We study the left APP-property of the skew generalized power series ring [[RS, ≤, ω]]. It is shown that if (S, ≤) is a commutative strictly totally ordered monoid, ω: S→ Aut (R) a monoid homomorphism and R a ring satisfying the descending chain condition on right annihilators, then [[RS, ≤, ω]] is left APP if and only if for any S-indexed subset A of R, the ideal lR(∑a ∈ A ∑s ∈ S Rωs (a)) is right s-unital.
THE STRONG SYMMETRIC GENUS OF DIRECT PRODUCTS
Authors: MAY COY L.
Published: April 2011

Let G be a finite group. The strong symmetric genus σ0(G) is the minimum genus of any Riemann surface on which G acts faithfully and preserving orientation. Assume that G is non-abelian and generated by two elements, one of which is an involution, and that n is relatively prime to |G|. Our first main result is the determination of the strong symmetric genus of the direct product Zn ×G in terms of n, |G|, and a parameter associated with the group G. We obtain a variety of genus formulas. Finally, we apply these results to prove that for each integer g ≥ 2, there are at least four groups of strong symmetric genus g.
SCHUR ELEMENTS AND BASIC SETS FOR CYCLOTOMIC HECKE ALGEBRAS
Authors: CHLOUVERAKI MARIA , JACON NICOLAS
Published: April 2011

We study the Schur elements and the a-function for cyclotomic Hecke algebras. As a consequence, we show the existence of canonical basic sets, as defined by Geck–Rouquier, for certain complex reflection groups. This includes the case of finite Weyl groups for all choices of parameters (in characteristic 0).
I-COMPACT RIGHT CHAIN DOMAINS
Authors: BRUNGS H. H. , TÖRNER G.
Published: April 2011

Generalizing the concept of convergency to valued fields, Ostrowski in the 1930s introduced pseudo-convergent sequences. In the present paper we classify pseudo-convergent sequences in right chain domains R according to the prime ideal P associated to the breadth I of the sequence using an ideal theory developed for right cones in groups. The ring R is I-compact if every pseudo-convergent sequence in R with breadth I has a limit in R, and we construct right chain domains R which are I-compact only for right ideals I in particular subsets [Formula: see text] of the set of all right ideals of R. Krull's perfect valuation rings and then Ribenboim's notion of a valuation ring complete par étages, where [Formula: see text] is the minimal set containing the completely prime ideals in a commutative valuation ring, is a special case. For a non-discrete right invariant rank-one right chain domain R there are exactly two possibilities for the set [Formula: see text] if the value group of R is the group of real numbers under addition, and there are infinitely many possibilities for [Formula: see text] in all other cases.
ON LOCALLY EHRESMANN SEMIGROUPS
Authors: REN XUEMING , YANG DANDAN , SHUM K. P.
Published: April 2011

It was first proved by McAlister in 1983 that every locally inverse semigroup is a locally isomorphic image of a regular Rees matrix semigroup over an inverse semigroup and Lawson in 2000 further generalized this result to some special locally adequate semigroups. In this paper, we show how these results can be extended to a class of locally Ehresmann semigroups.
A CHARACTERIZATION OF GOLDIE EXTENDING MODULES OVER DEDEKIND DOMAINS
Authors: AKALAN EVRIM , BIRKENMEIER GARY F. , TERCAN ADNAN
Published: April 2011

In this paper, we characterize [Formula: see text]-extending (Goldie extending) modules over Dedekind domains and we use the [Formula: see text]-extending condition to characterize the modules over a principal ideal domain whose pure submodules are direct summands. Moreover, we show that if R is a principal ideal domain, then the class of [Formula: see text]-extending modules is closed under direct summands and that if R is a Dedekind domain, then the class of [Formula: see text]-extending torsion modules is closed under finite direct sums.
ON STRONGLY *-CLEAN RINGS
Authors: LI CHUNNA , ZHOU YIQIANG
Published: April 2011

A *-ring R is called a *-clean ring if every element of R is the sum of a unit and a projection, and R is called a strongly *-clean ring if every element of R is the sum of a unit and a projection that commute with each other. These concepts were introduced and discussed recently by [L. Vaš, *-Clean rings; some clean and almost clean Baer *-rings and von Neumann algebras, J. Algebra324 (2010) 3388–3400]. Here it is proved that a *-ring R is strongly *-clean if and only if R is an abelian, *-clean ring if and only if R is a clean ring such that every idempotent is a projection. As consequences, various examples of strongly *-clean rings are constructed and, in particular, two questions raised in [L. Vaš, *-Clean rings; some clean and almost clean Baer *-rings and von Neumann algebras, J. Algebra324 (2010) 3388–3400] are answered.
SOLUBLE MAXIMAL SUBGROUPS IN GLn(D)
Authors: DORBIDI H. R. , FALLAH-MOGHADDAM R. , MAHDAVI-HEZAVEHI M.
Published: April 2011

Let D be an F-central non-commutative division ring. Here, it is proved that if GL n(D) contains a non-abelian soluble maximal subgroup, then n = 1, [D : F] < ∞, and D is cyclic of degree p, a prime. Furthermore, a classification of soluble maximal subgroups of GL n(F) for an algebraically closed or real closed field F is also presented. We then determine all soluble maximal subgroups of GL 2(F) for fields F with Char F ≠ 2.
USING GRÖBNER BASES FOR FACTORING POLYNOMIALS OVER ALGEBRAIC EXTENSION FIELDS
Authors: HASHEMI AMIR , M.-ALIZADEH BENYAMIN
Published: April 2011

In this paper, we present a simple and efficient algorithm for factoring an arbitrary univariate polynomial over algebraic extension fields, using Gröbner bases. We have implemented our algorithm in MAPLE and we evaluate its performance via some examples.
MULTIVALUED GENERALIZATIONS OF THE FRANKL–PACH THEOREM
Authors: HEGEDŰS GÁBOR , RÓNYAI LAJOS
Published: April 2011

In [On disjointly representable sets, Combinatorica4 (1984) 39–45] Frankl and Pach proved the following uniform version of Sauer's lemma.

Let n,d,s be natural numbers such thatd ≤ n, s + 1 ≤ n/2. Let [Formula: see text] be an arbitrary d-uniform set system such that [Formula: see text] does not shatter an s + 1-element set, then[Formula: see text] We prove here two generalizations of the above theorem to n-tuple systems. To obtain these results, we use Gröbner basis methods, and describe the standard monomials of Hamming spheres.
RINGS WITH THE BEACHY–BLAIR CONDITION
Authors: RODRÍGUEZ-JORGE ELENA
Published: April 2011

A ring satisfies the left Beachy–Blair condition if each of its faithful left ideal is cofaithful. Every left zip ring satisfies the left Beachy–Blair condition, but both properties are not equivalent. In this paper we will study the similarities and the differences between zip rings and rings with the Beachy–Blair condition. We will also study the relationship between the Beachy–Blair condition of a ring and its skew polynomial and skew power series extensions. We give an example of a right zip ring that is not left zip, proving that the zip property is not symmetric.
COMPARISON OF c AND d-SEQUENCES
Authors: KULOSMAN HAMID
Published: April 2011

In our previously published papers [Monomial sequence of linear type, Illinois J. Math.52 (2008) 1213–1221; Sequences between d-sequences and sequences of linear type, Comment. Math. Univ. Carolin.50 (2009) 1–9; Two-generated ideals of linear type, Acta Math. Univ. Comenian. (N.S.)78 (2009) 97–102] we have introduced and discussed the notion of a c-sequence in a commutative ring. In this paper we compare this notion with the notion of a d-sequence. The ideal generated by any of these sequences is of linear type. We show that there are c-sequences that are not d-sequences and that c-sequences satisfy analogs of sharp Artin–Rees properties that hold for d-sequences. We also discuss closeness of c and d-sequences.
SOME PROPERTIES ON THE SCHUR MULTIPLIER OF A PAIR OF LIE ALGEBRAS
Authors: RISMANCHIAN MOHAMMAD REZA , ARASKHAN MEHDI
Published: April 2011

The aim of this paper is to introduce the concept of the Schur multiplier [Formula: see text] of a pair of Lie algebras and to obtain some inequalities for the dimension of [Formula: see text]. Also, we consider some of the features of central extension of an arbitrary Lie algebra. Moreover, we present a necessary and sufficient condition in which the Schur multiplier of a pair of Lie algebras can be embedded into the Schur multiplier of their factor Lie algebras.
ON HAMILTONIAN GROUP OF MULTISYMPLECTIC MANIFOLDS
Authors: SHAFIEE M.
Published: April 2011

In this paper the Hamiltonian group Ham (M, Ω) is defined for a compact k-plectic manifold (M, Ω) and it is shown that its Lie algebra is the space of equivalence classes of Hamiltonian forms, modulo closed forms. Also if ψ be a multisymplectomorphism in the identity component Msymp 0(M, Ω) of the group of multisymplectomorphisms Msymp (M, Ω), we obtain a necessary and sufficient condition under which ψ belongs to Ham (M, Ω). As two consequences, we show that Hamiltonian paths are generated by Hamiltonian forms and if Hk (M, ℝ) = 0, then Ham (M, Ω) is equal to Msymp 0(M, Ω).
A FAMILY OF EINSTEIN RANDERS METRICS
Authors: NAJAFI B. , TAYEBI A.
Published: April 2011

We classify all Einstein Randers metric on R4 constructed from ga, the Hawking Taub–NUT metric, and a homothetic vector field W for ga in the Zermelo navigation representation. All of these Einstein Randers metrics are Ricci-flat and are not of scalar flag curvature. Finally, the moduli space of constructed Randers metrics is obtained.
ATTRACTOR FLOWS IN st2 BLACK HOLES
Authors: ROYCHOWDHURY RAJU
Published: April 2011

Following the same treatment of Bellucci et al. we obtain, the hitherto unknown general solutions of the radial attractor flow equations for extremal black holes, both for non-BPS with non-vanishing and vanishing central charge Z for the so-called st2 model, the minimal rank-two [Formula: see text] symmetric supergravity in d = 4 space-time dimensions.

We also make useful comparisons with results that already exist in literature, and introduce the fake supergravity (first-order) formalism to be used in our analysis. An analysis of the BPS bound all along the non-BPS attractor flows and of the marginal stability of corresponding D-brane charge configurations has also been presented.
GENERAL EULER TOP SYSTEM AND ITS LAX REPRESENTATION
Authors: IVAN GHEORGHE , IVAN MIHAI
Published: April 2011

The main purpose of this paper is to give the Lax representation of the general Euler top system.
CROSSED MODULE BUNDLE GERBES; CLASSIFICATION, STRING GROUP AND DIFFERENTIAL GEOMETRY
Authors: JURČO BRANISLAV
Published: April 2011

We discuss nonabelian bundle gerbes and their differential geometry using simplicial methods. Associated to a (Lie) crossed module (H → D) there is a simplicial group [Formula: see text], the nerve of the groupoid [Formula: see text] defined by the crossed module, and its geometric realization, the topological group [Formula: see text]. We introduce crossed module bundle gerbes so that their (stable) equivalence classes are in a bijection with equivalence classes of principal [Formula: see text]-bundles. We discuss the string group and string structures from this point of view. Also, we give a simplicial interpretation to the bundle gerbe connection and bundle gerbe B-field.
PERCEIVED COMPETITION AND INNOVATIVE INTENTIONS IN DUTCH SMALL AND MEDIUM-SIZED ENTERPRISES
Authors: DE JONG JEROEN P. J.
Published: April 2011

This paper explores the complex relationship between competition and innovation by analyzing survey data of 2,281 small and medium-sized enterprises (SMEs) in the Netherlands. We develop and test hypotheses on the relationships between three dimensions of perceived competition (internal rivalry, supplier power and buyer power) and firms' intentions to engage in product and process innovation. Moreover, we analyze if firms' strategic attention for innovation is a moderating variable. We find that specific innovative intentions relate to different perceptions of competitive forces. Intentions to engage in process innovation correlate with the perceived bargaining power of suppliers, while intended product innovation correlates with perceived buyer power and internal rivalry between incumbent firms in the market — but the correlation with internal rivalry is significant only when firms report no strategic attention for innovation.
THE IMPACT OF INTERPERSONAL NETWORKS ON THE INNOVATIVENESS OF INVENTORS: FROM THEORY TO EMPIRICAL EVIDENCE
Authors: CHASSAGNON VIRGILE , AUDRAN MARILYNE
Published: April 2011

This paper aims to investigate the impact of interpersonal networks on the innovativeness of inventors. A significant amount of literature has been devoted to the analysis of network effects in the economic and managerial sciences. The main research works in this field have emphasized the strong relation between interpersonal networks and cooperation. Cooperation is the best way to succeed in complex and innovative projects. We make here the hypothesis that repeated collaborations in a network of inventors have an influence on their innovativeness, i.e., on their dynamic innovative capacity. On the one hand, we propose some theoretical clarifications regarding interpersonal networks and innovativeness, and we summarize the main conclusions of the more important empirical work connected with this subject. On the other hand, we run an empirical study involving 1,157 French prolific inventors who obtained 30,477 patents for the period 1975–2002. Logistic regressions results underline the significant impact of extended collaborations on the innovativeness of inventors.
THE IMPACT OF THE PERCEIVED USEFULNESS OF WORKPLACE SOCIAL NETWORKS UPON THE INNOVATIVE BEHAVIOUR OF SME EMPLOYEES: A SOCIAL CAPITAL PERSPECTIVE
Authors: XERRI MATTHEW J. , BRUNETTO YVONNE
Published: April 2011

This research includes an examination about the impact of three organisational factors upon the perceived usefulness of workplace social networks for problem solving in engineering SMEs. As well this research examines the impact of the perceived usefulness of workplace social networks upon the innovative behaviour of engineering SME employees. More specifically, the dimensions of Social Capital Theory are applied as a lens to develop an understanding into the effect of the strength of workplace social network ties, sociability and organisational culture upon the perceived usefulness of workplace social networks for problem solving. This study examines the proposed model by applying mixed methods. The research method includes a survey with engineering employees' and interviews with senior management. The findings confirm that the organisational factors tested (tie strength, sociability and organisational culture) impact upon the perceived usefulness of workplace social networks for problem solving. Furthermore, the findings also confirmed that the perceived usefulness of workplace social networks affects the innovative behaviour of engineering SME employees. Therefore, this research adds to the current body of literature by providing insight into the usefulness of workplace social networks for problem solving and the impact this has on the innovative behaviour of engineering SME employees.
ARE PUBLISHERS READY FOR TOMORROW? PUBLISHERS' CAPABILITIES AND ONLINE INNOVATIONS
Authors: VALANTO VERA , KOSONEN MIIA , ELLONEN HANNA-KAISA
Published: April 2011

In order to cope with technological change, publishing companies need to effectively combine their capabilities and use them to support the development of new and existing products. In this paper, we explore the relationship between the market and technology capabilities of publishing companies and their online innovations. Our comparative case study focuses on four cases representing newspaper and magazine publishers. The case companies seem stronger in market than in technology capabilities. We also note an apparent tendency to build on the strongest capability area and to focus on leveraging those capabilities rather than taking a risk and experimenting in an area in which they are relatively weaker. Further, it seems that publishers have been able to leverage their market capabilities through online experimentation, but have not been able to develop their technological capabilities in the same manner. From the scientific perspective, this study makes two main contributions. Firstly, the empirical in-depth investigation of the capability portfolios of the case firms complements the emerging work on innovation-related capabilities. Secondly, the study adds to the literature on media management in enhancing understanding of the online-related capabilities that are required in publishing companies, and the related development patterns. Our study suggests that experimenting online and producing innovations requiring new types of internal market-related processes and practices is an efficient strategy to develop one's current market capabilities online.
INNOVATION STRATEGY, WORKING CLIMATE, AND FINANCIAL PERFORMANCE IN TRADITIONAL MANUFACTURING FIRMS: AN EMPIRICAL ANALYSIS
Authors: NYBAKK ERLEND , JENSSEN JAN INGE
Published: April 2011

In this study, we address the effect of innovation strategy and an innovative working climate on financial performance in the Norwegian wood industry. Innovation strategy embodies four dimensions: the degrees to which innovation in the form of products, processes, and business systems are embedded in the management values and priorities as well as the degree of expenditure in R&D. An innovative working climate is exemplified by team cohesion, supervisory encouragement, resources, autonomy, challenge, and openness to innovation. Previous studies have indicated a lack of research in traditional manufacturing firms on both innovation strategy and a supportive working climate. Our survey was answered by 241 CEOs. The connectional model was tested with structural equation modelling, and all hypotheses received support. This result implied that innovation strategy and an innovative working climate enhanced financial performance in traditional manufacturing firms.
A MODEL OF ORGANIZATIONAL INNOVATION IMPLEMENTATION EFFECTIVENESS IN SMALL TO MEDIUM FIRMS
Authors: SAWANG SUKANLAYA , UNSWORTH KERRIE L.
Published: April 2011

The present study aims to validate the current best-practice model of implementation effectiveness in small and mid-size businesses. Data from 135 organizations largely confirm the original model across various types of innovation. In addition, we extended this work by highlighting the importance of human resources in implementation effectiveness and the consequences of innovation effectiveness on future adoption attitudes. We found that the availability of skilled employees was positively related to implementation effectiveness. Furthermore, organizations that perceived a high level of benefits from implemented innovations were likely to have a positive attitude towards future innovation adoption. The implications of our improvements to the original model of implementation effectiveness are discussed.
Randomized algorithms for estimating the trace of an implicit symmetric positive semi-definite matrix
Authors: Avron Haim , Toledo Sivan
Published: April 2011

We analyze the convergence of randomized trace estimators. Starting at 1989, several algorithms have been proposed for estimating the trace of a matrix by 1/MΣ
i
=1
M
z

i

T

Az

i

, where the
z

i

are random vectors; different estimators use different distributions for the
z

i

s, all of which lead to
E
(1/MΣ

i

=1

M

z

i

T
Az

i

) = trace(
A
). These algorithms are useful in applications in which there is no explicit representation of
A
but rather an efficient method compute
z
T
Az
given
z
. Existing results only analyze the variance of the different estimators. In contrast, we analyze the number of samples
M
required to guarantee that with probability at least 1-δ, the relative error in the estimate is at most ϵ. We argue that such bounds are much more useful in applications than the variance. We found that these bounds rank the estimators differently than the variance; this suggests that minimum-variance estimators may not be the best.

We also make two additional contributions to this area. The first is a specialized bound for projection matrices, whose trace (rank) needs to be computed in electronic structure calculations. The second is a new estimator that uses less randomness than all the existing estimators.
ImaNote
Authors: Díaz Lily , Reunanen Markku , Acuña Blanca , Timonen Atte
Published: April 2011

We have created a tool called ImaNote (Image Map Annotation Notebook) for viewing, zooming, and annotating arbitrary-sized images using a Web browser. Multiple users can work with the tool simultaneously, being able to almost instantly see and edit each other's modifications. In this article we describe the design, implementation, and user interface of ImaNote focusing on issues arising from the Web-based nature of the software, as well as from its intended use as a tool for visualization and interaction with digital surrogates, facsimiles, and replicas of cultural heritage objects.
Pitfalls and misconceptions in component-oriented approaches for real-time embedded systems
Authors: Panunzio Marco , Vardanega Tullio
Published: April 2011

When the task befalls you to devise a novel component-oriented approach for real-time embedded systems you first dutifully undertake a thorough scrutiny of the import and pitfalls of previous attempts. This is what we have done for the last couple of years, in the context of an initiative promoted by the European Space Agency for the creation of a component model to serve the development of new-generation on-board software. In this paper we recapitulate the lessons we learned in that effort.
Implementation of compositional scheduling framework on virtualization
Authors: Yang Jungwoo , Kim Hyungseok , Park Sangwon , Hong Changki , Shin Insik
Published: April 2011

Virtualization has been receiving increasing attention in embedded real-time systems. However, real-time systems, whose correctness depends on timing requirements, are not easily applicable to virtualization since virtualization mainly focuses on functional correctness. A hierarchical scheduling framework (HSF) provides a method of composing the complex timing requirements of real-time systems. There have been several works on the implementation of the HSF. Although the scheduling framework of virtualization directly corresponds to the HSF, they did not consider implementing the HSF on virtualization. In this paper, we implement a two-level HSF, where components use a periodic interface model using virtualization. We use an L4/Fiasco micro-kernel as a virtual machine monitor (VMM) and an L4Linux as a virtual machine (VM) and extend these to support real-time properties. The experimental results show that the HSF is suitable for the virtualization environment.
CARTS
Authors: Phan Linh T. X. , Lee Jaewoo , Easwaran Arvind , Ramaswamy Vinay , Chen Sanjian , Lee Insup , Sokolsky Oleg
Published: April 2011

As real-time embedded systems are increasingly complex, integration becomes a great challenge in their design and development. Managing complexity of the system design is therefore essential for high-assurance and cost-effective development. Component-based design has consequently been developed and gained its importance over the years as a powerful technique for complexity management. In this design paradigm, a large complex system is first decomposed into smaller and simpler components - which are developed independently - before recomposing them into a complete system using interfaces that abstract away their internal complexities.
Ubiquity symposium: What have we said about computation?
Authors: Denning Peter J.
Published: April 2011

The "computation" symposium presents the reflections of thinkers from many sectors of computing on the fundamental question in the background of everything we do as computing professionals. While many of us have too many immediate tasks to allow us time for our own deep reflection, we do appreciate when others have done this for us. Peter Freeman points out, by analogy, that as citizens of democracies we do not spend a lot of time reflecting on the question, "What is a democracy," but from time to time we find it helpful to see what philosophers and political scientists are saying about the context in which we act as citizens.
Origin of White Luminescence in Ag-Eu Co-doped Oxyfluoride Glasses
Authors: Guo Hai , Li JingJing , Li Fang , Zhang Hao
Published: April 2011

A combination of red, green and blue emissions has emerged to achieve pure white emission (X = 0.323, Y = 0.320) in Ag-Eu co-doped oxyfluoride glasses. The type of luminescent species, the origin of white emission and the enhancement mechanism for red and blue emissions were investigated by means of absorption, emission and excitation spectra, decay lifetime measurements, as well as time-resolved spectroscopy. Results prove that white emission is originated from f-f transitions of Eu3+ (red), ML-Ag (very small molecule-like, non-plasmonic Ag particles, green) and 5d-4f transition of Eu2+ (blue). Our researches show that Ag-Eu co-doped glasses may provide a new platform to design and fabricate novel phosphors for ultraviolet light-emitting diode (LED) chips.