Arhivă — Seria A

1

ITERATIVE APPROACH TO FRACTIONAL BOUNDARY VALUE PROBLEMS WITH APPLICATIONS

Muhammad KHAN, Mujahid ABBAS, Cristian CIOBANESCU

The aim of this paper is to approximate solutions for a class of boundary value problems involving Caputo fractional-order differential equa- tions by employing a novel iterative scheme. A numerical experiment is presented to illustrate the applicability of the method and to support the the- oretical findings. The resu…

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2

SHARPER BOUNDS FOR D’AURIZIO-S ´ANDOR TRIGONOMETRIC INEQUALITIES

Mohammad W. ALOMARI and Gabriel BERCU

We obtain new polynomial bounds for trigonometric quotients appearing in the D’Aurizio–S´andor inequalities on (0, π/2). Using convexity properties of suitably normalized functions, quadratic and quartic bounds with sharp constants are derived.

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3

DIRICHLET CHARACTER MODULO 4 ON PARTITIONS

Mircea MERCA

We extend the Dirichlet character modulo 4 to integer partitions via an additive statistic on their parts, and introduce several associated partition functions under natural restrictions. Using generating function techniques and classical q-series identities, we establish formulas relating these func- tions, including …

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4

A DOUBLE INERTIAL SELF-ADAPTIVE SUBGRADIENT EXTRAGRADIENT METHOD WITH CONJUGATE GRADIENT DIRECTION FOR VARIATIONAL INEQUALITIES

Tianyu ZHANG, Youli YU, Yonghong YAO

In this paper, we propose a novel double inertial self-adaptive subgradient extragradient method with conjugate gradient direction for solving variational in- equality problems involving quasi-monotone and Lipschitz continuous operators in real Hilbert spaces. The proposed algorithm incorporates the technique of double…

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5

ON ϕ-FIXED POINTS FOR IMPLICIT CONTRACTIVE CONDITIONS

Monica STANCIU

In this work, existence results of fixed points are proved for op- erators which fulfill weakly implicit contractive inequalities defined by means of auxiliary functions with adequate properties. Additionally, these fixed points are zeros of a function endowed with the lower semi continuity, in the setting of extended …

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6

GLOBAL EXISTENCE AND NONEXISTENCE FOR A GENERALIZED PSEUDO-PARABOLIC EQUATION WITH VARIABLE EXPONENTS AND LOGARITHMIC NONLINEARITIES

Mohammed Yassine TRIGUI

In this paper, we study pseudo-parabolic equations with logarithmic nonlinearity and a singular potential, involving variable exponents under suitable assumptions. Using energy methods, we show that solutions with negative initial energy blow up in finite time, and we then extend this blow-up result to a class of solut…

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7

STABILITY OF SWITCHED GENE REGULATORY NETWORKS MODEL

Donal O’REGAN, Snezhana HRISTOVA, Valentin GEORGIEV

Stability properties of the equilibrium of the model of switched gene regu- latory networks is studied. The switching rule as well as the switching times are given initially and the switching rule is a piecewise constant function. The algo- rithm for construction of the solution is provided and the equilibrium is defin…

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8

ON A NATURAL YANG-MILLS SURFACE PRODUCED BY THE RABINOVICH-FABRIKANT DYNAMICAL SYSTEM

Ana-Maria BOLDEANU

Using the least squares variational method, we construct the Lagran-ge-Hamilton geometry (in the sense of Lagrangian nonlinear connec- tion, Lagrangian d-torsions, Lagrangian Yang-Mills electromagnetic-like en- ergy, Hamiltonian nonlinear connection and Hamiltonion d-torsions) deter- mined by the important Rabinovich-F…

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9

MIZOGUCHI AND TAKAHASHI’S θ-TYPE FIXED POINT THEOREM IN v-GENERALIZED METRIC SPACES

Wei MING, Tayyab KAMRAN, Hamza KHAN, Umar ISHTIQ, Mohammad AKRAM

In this paper we introduce the notion of Mizoguchi-Takahashi’s θ-type contraction and obtain a fixed point theorem. We have established nontrivial examples to show that our result not only generalizes Nadler’s fixed point theorem in v-generalized metric spaces but it also generalizes Nadler’s fixed point theorem, Mizog…

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10

DISCRETE CHARACTERIZATIONS FOR THE INDIVIDUAL EXPONENTIAL (IN)STABILITY OF EVOLUTIONARY PROCESSES

Yuanyuan WU, Tian YUE, Jie ZHANG

In this paper, inspired by the published work (Acta Math. Hun- gar., 153(1)(2017): pp. 16-23), we further investigate the individual sta- bility and instability of evolutionary processes in Banach spaces. From a discrete-time perspective, we derive new Datko-type criteria for individual exponential stability. Furthermo…

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11

A FAMILY OF GEOMETRIC CONSTANTS AND THE FIXED POINT PROPERTY FOR MULTIVALUED NON-EXPANSIVE MAPPINGS

Chao XIA, Junqing YIN, Xi WANG

The existence of fixed points for multivalued nonexpansive map- pings is closely related to the geometric structure of the underlying Banach space. In this paper, sufficient conditions are established on a Banach space X in terms of the generalized geometric constant Cλ,t(X), the asymptotic coefficient R(1, X), and the…

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12

AN EKELAND-TYPE VARIATIONAL PRINCIPLE IN STRICTLY DIAGONAL PARTIAL METRIC SPACES

Abdelbasset FELHI1

We establish an Ekeland-type variational principle in a class of partial metric spaces whose diagonal map is strictly Lipschitz with respect to the associated symmetrized metric. This assumption gives a two-sided comparison between the induced quasi-metric and the symmetrized metric, and it permits the transfer of vari…

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13

GLOBAL SMALL SOLUTION TO A CLASS OF CAHN-HILLIARD EQUATION WITH NONLINEAR DIFFUSION

Yurong BAO, Huanzhang SUN, Xiaopeng ZHAO

In this paper, we consider the properties of solutions for the Cauchy problem of a class of Cahn-Hilliard equation with nonlinear diffusion de- scribing the dynamics of phase transitions in ternary oil-water-surfactant systems. We prove the existence of a unique global-in-time solution, analyticity and decay estimates …

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14

TRIGONOMETRIC ANALYTICAL SOLUTION OF THE PULSATORY LIPOSOME

Diana R. RADNEF-CONSTANTIN, Sorin S. RADNEF, Dumitru POPESCU

The model of the pulsatory liposome as a three-phase biophysical mo- tor is solved analytically using the basic constitutive differential equations. Adopting a trigonometric approximation for the pore radius, analytical ex- pressions for the model functions described by the system of three differential equations are de…

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15

COMPOSITE ALGORITHM FOR SOLVING SPLIT VARIATIONAL INEQUALITY PROBLEM AND SPLIT VARIATIONAL INCLUSION PROBLEMS

Jin-Lin GUAN1

This paper aims to investigate a new composite algorithm for solving a split variational inequality problem and a split variational inclusion problem in real Hilbert spaces. Under very mild conditions, we prove a strong convergence theorem for the proposed algorithm. Furthermore, an application is given to illustrate t…

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16

PERFORMANCE OF A CONICAL TWO-SOLENOID FOCUSING SYSTEM FOR LASER-DRIVEN PROTONS

Laura-Anamaria Nalbaru, Michaela Arnold, Catalin M. Ticos

Charged particle beam acceleration techniques are rapidly evolving alongside advances in high-power laser technology. Laser-driven accelera- tion of charged particles is emerging as a compact alternative to conven- tional and costly radio-frequency accelerators, enabling particle generation through simple target config…

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17

ENGINEERING CHARGE TRANSFER AND STABILITY IN A CONFINED SYSTEM: ATOMIC TI4+ SITES WITHIN A MESOPOROUS SILICA MATRIX

Nasrine-Dalila TOUAA , Mohammed Mustapha BOUHENT , Kahina BENTALEB, Abdelkader BENDERRAG, Leila SAKER , Rachida OUARGLI SAKER, Zohra BOUBERKA, Narjess BELHADJ, Ulrich MASCHKE

A model system has been developed to study the effect of spatial confinement on the stability of photocatalysis. This system consists of Ti⁴⁺ sites dispersed throughout an SBA-15 silica framework. Tetrahedral Ti centres (0.47 wt%) were detected with a charge-transfer band at 220 nm. The photo-oxidation kinetics of a mo…

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18

STUDY OF HIGH-PERFORMANCE MPPT ALGORITHMS FOR BIPV APPLICATIONS

Ana-Maria BADEA, Doina MANAILA- MAXIMEAN, Dan CRACIUNESCU

Evaluating the electrical performance of photovoltaic (PV) systems and optimizing their energy output remains challenging due to the variability of meteorological conditions. This study presents a unified approach to the operational optimization of BIPV systems, relying on methodologies and tools commonly used for PV s…

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19

ASSESSMENTS OF ENVIRONMENTAL CONTAMINATION WITH UREA AND DIMETHYL UREA BASED ON FT-IR SPECTROSCOPIC INVESTIGATIONS ASSISTED BY NUMERICAL SIMULATIONS IN GAUSSIAN 6 SOFTWARE

Bogdan GAVRILUT, Georgiana COCEAN, Aura DARABĂ, Iuliana COCEAN, Silviu GURLUI and Alexandru COCEAN

The paper presents a method for identifying pollutant compounds in the atmosphere that are brought to the ground in the form of ice and sleet, the later resulting into foaming waters. The method of investigation consists of FT-IR analysis to identify chemical compounds based on the vibration bands of functional groups …

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20

STUDY OF WORK TEAMS ACTIVITY BY ASYMMETRICAL PULSES MODEL

Bogdan G.-M. DUMITRU, Ionuţ VLĂDOIU, Andrei-Alexandru GEANTĂ

This article presents the use of the asymmetric pulses model written under the binomial form (𝑎𝑎 + 𝑏𝑏𝑏𝑏)𝑛𝑛 , n being the number of the system’s constituents with a ≠ b some parameters of a certain medium, for studying the opportunity and correctness of modernizing some working methods in engineering education. Consider…

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21

ANALYSIS OF OPTICAL DIFFERENCES BETWEEN HEALTHY AND MALIGNANT OROPHARYNGEAL TISSUE USING AUTOFLUORESCENCE SIGNALS

Ruxandra Ioana STANCALIE-NEDELCU, Răzvan MIHALCEA, Șerban BERTESTEANU, Ionuț Relu ANDREI, Adriana SMARANDACHE Tatiana TOZAR, Raluca GRIGORE

In the last years, there has been an increasing interest in the application of Laser Induced Autofluorescence (LIAF) as a noninvasive method for identifying alterations in biochemistry and tissue structure changes. Using a single case of oropharyngeal squamous cell carcinoma, we carried out an initial assessment to see…

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