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Search Results: 1 - 10 of 4085 matches for " Eugène Ndenzako "
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The Explicit Fatunla’s Method for First-Order Stiff Systems of Scalar Ordinary Differential Equations: Application to Robertson Problem  [PDF]
Hippolyte Nyengeri, Eugène Ndenzako, Rénovat Nizigiyimana
Open Access Library Journal (OALib Journal) , 2019, DOI: 10.4236/oalib.1105291
Ordinary differential equations (ODEs) are among the most important mathe-matical tools used in producing models in the physical sciences, biosciences, chemical sciences, engineering and many more fields. This has motivated re-searchers to provide efficient numerical methods for solving such equations. Most of these types of differential models are stiff, and suitable numerical methods have to be used to simulate the solutions. This paper starts with a sur-vey on the basic properties of stiff differential equations. Thereafter, we present the explicit one-step algorithm proposed by Fatunla to solve stiff systems of first-order scalar ODEs. As an illustrative example, we consider the Robertson problem (RP) which is known to be stiff. The results obtained with the explicit Fatunla method (EFM) are compared with those computed by the solver RADAU which is based on implicit Runge-Kutta methods. Our results are in good agreement with the latter ones.
Frobenius Series Solutions of the Schrodinger Equation with Various Types of Symmetric Hyperbolic Potentials in One Dimension  [PDF]
Hippolyte Nyengeri, René Simbizi, Audace Girukwishaka, Rénovat Nizigiyimana, Eugène Ndenzako
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104728
The Schrodinger equation (SE) for a certain class of symmetric hyperbolic potentials is solved with the aid of the Frobenius method (FM). The bound state energies are given as zeros of a calculable function. The calculated bound state energies are successively substituted into the recurrence relations for the expanding coefficients of the Frobenius series representing even and odd solutions in order to obtain wave functions associated with even and odd bound states. As illustrative examples, we consider the hyperbolic Poschl-Teller potential (HPTP) which is an exactly solvable potential, the Manning potential (MP) and a model of the Gaussian potential well (GPW). In each example, the bound state energies obtained by means of the FM are presented and compared with the exact results or the literature ones. In the case of the HPTP, we also make a comparison between exact bound state wave functions and the eigenfunctions obtained by means of the present approach. We find that our results are in good agreement with those given by other methods considered in this work, and that our class of potentials can be a perfect candidate to model the GPW.
Application of the Frobenius Method to the Schrodinger Equation for a Spherically Symmetric Hyperbolic Potential  [PDF]
Hippolyte Nyengeri, Rénovat Nizigiyima, Eugène Ndenzako, Félix Bigirimana, Dieudonné Niyonkuru, Audace Girukwishaka
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104950
In this paper, an efficient technique for computing the bound state energies and wave functions of the Schrodinger Equation (SE) associated with a new class of spherically symmetric hyperbolic potentials is developed. This technique is based on a recent approximation scheme for the orbital centrifugal term and on the use of the Frobenius method (FM). The bound state eigenvalues are given as zeros of calculable functions. The corresponding eigenfunctions can be obtained by substituting the calculated energies into the recurrence relations for the expanding coefficients of the Frobenius series representing the solution. The excellent performance of this technique is illustrated through numerical results for some special cases like Poschl-Teller potential (PTP), Manning-Rosen potential (MRP) and Poschl-Teller polynomial potential (PTPP), with an application to the Gaussian potential well (GPW). Comparison with other methods is presented. Our results agree noticeably with the previously reported ones.
Psicanálise e ciências sociais
Enriquez, Eugène;
ágora: Estudos em Teoria Psicanalítica , 2005, DOI: 10.1590/S1516-14982005000200001
Abstract: this article attempts to research the relations between psychoanalysis and social sciences with a critical sight on the advances concerning the field of psychoanalytical studies related to social subjects as well as that of sociological studies influenced by psychoanalysis, since freud until nowadays. the article is based specially on the defense of the psychoanalytical approach of the social field, showing that it's not about an inadequate use of the psychoanalysis, but the fact that it's not possible to think in a psychoanalysis outside that field once the constitution of the subject is made exactly by the entrance in the social field.
O indivíduo preso na armadilha da estrutura estratégica
Enriquez, Eugène;
Revista de Administra??o de Empresas , 1997, DOI: 10.1590/S0034-75901997000100003
Abstract: nowadays, in the highest point of individualism, it is possible to say that individual has never been so entangled in the organizations and has never been so little free regarding his own body and his way of thinking. today, everything in society and in the organizations is built in order to make the individual believe in his vocation for being free and creative.
Os desafios éticos nas organiza??es modernas
Enriquez, Eugène;
Revista de Administra??o de Empresas , 1997, DOI: 10.1590/S0034-75901997000200002
Abstract: the reappearance of ethical concems reflects the profound disquiet in our societies in the wake of the triumph of instrumental rationality, with its tendency of making human beings into manipulatable objects. this perversion of rationality finds its expression particularly in companies, in spite of the fact that they are attempting to integrate a concem for ethics into their functioning at this time. it can be observed that, in doing this, their goal is most frequently to develop a strong consensus around the ideais from which they take their inspiration, both from their members and from the social body as a whole. we must ask what are the real ethical issues that confront modem organizations. to this end, the ethics of conviction, of responsability and of discussion are reviewed here. a fourth form of ethics, the ethics of finitude are considered. can organizations make a place for this ethics? the question is in any case worth asking.
Producción minero-metalúrgica antigua y catástrofes ecológicas antropogénicas: una introducción al problema
Chernykh, Eugène N.
Trabajos de Prehistoria , 1994,
Abstract: Not available El artículo es una introducción al problema de la interdependencia entre la metalurgia antigua y las catástrofes ecológicas. El método de estudio propuesto depende de los enfoques planteados en el trabajo. El principal, la determinación de dos estadios, uno pre-industrial y otro industrial, en el desarrollo de la metalurgia se basa en el tipo de energía utilizado para la reducción del metal. En el caso del estadio pre-industrial que ha durado casi seis milenios, desde el V milenio a.C. hasta el siglo XVIII a.D. el tipo de energía no varió: el carbón vegetal. Ello nos ha permitido extrapolar los cálculos del consumo de este tipo de combustible en época moderna a la Prehistoria. Ello ha sido posible gracias sobre todo a los estudios efectuados en el conjunto minero de Kargali, en la región del Ural meridional, donde hay restos de minas prehistóricas y modernas. La evaluación del nivel de extracción minera y de metalurgia pre-indutrial indica un inmenso consumo de carbón vegetal que llevó a la desaparición de los bosques y tuvo consecuencias muy graves desde el punto de vista ecológico lo que a su vez, dio lugar a problemas sociales y culturales en las comunidades humanas. Como conclusión se propone una periodización de las Primeras Edades del Metal, y se determinan los territorios donde se podría esperar diversos grados de presión ecológica, así como las consecuencias que se analizan a lo largo del texto. [fr] L'ancienne production minière et métallurgique et les catastrophes écologiques anthropogènes: introduction au problème. L'article présente une introduction sur le problème de l'interdépendance de la métallurgie ancienne et des catastrophes écologiques. La méthode d'étude proposée dépend des approches posées dans le travail. La principale, la détérmination de deux stades. pré-industriel et industriel, dans le développement de la métallurgie se base sur le type de l'énergie utilisée pour la réduction du métal. Pour le stade pré-industriel qui a duré presque six millénaires, du Ve millénaire avant J.C. jusqu'au XVIIIe siècle A.D., ce type d'énergie etait toujours le même - le charbon de bois. Cela nous a permis d'extrapoler les calculs de la consommation de ce genre de combustible aux temps modernes dans la Préhistoire. Surtout c'est devenu possible avec les études de l'ensemble de mines Kargali dans la région d'Oural du Sud qui y contient les restes des mines préhistoriques et modernes. L'évaluation du niveau de l'ex traction minière et de la métallurgie pré-industrielle suppose une immense consommation du charbon de bois qui menait à l'
A constru o amorosa
Eugène Enriquez
Psicologia em Revista , 2003,
Abstract: O sentimento amoroso terá desaparecido em favor da sexualidade? Apesar de certas tendências céticas e cínicas de nossas sociedades desenvolvidas, o amor continua a se manifestar, já n o tanto como um “amor louco” que corre o risco de terminar brutal ou tragicamente, mas na forma de uma paix o pacientemente construída, que favorece a reciprocidade dos investimentos dos dois parceiros, situados em rela es simétricas, partilhando prazer, felicidade e sofrimento e que, sem deixar de lado a sexualidade, seja capaz de um trabalho de sublima o e de mentaliza o. Assim, o amor por si mesmo n o se separa do amor pelo outro, a proximidade n o exclui o conflito, o desejo n o bloqueia o pensamento. Além do mais, o amor pelo outro, quando expandido no amor sublimado pelos outros, permite que serealize o trabalho da cultura.
Parallelism between locally conformal symplectic manifolds and contact manifolds
Eugène Okassa
Mathematics , 2015,
Abstract: We give the parallelism between locally conformal symplectic manifolds and contact manifolds. We also give the generalization of exact contact manifolds.
Presumed Symbolic Use of Diurnal Raptors by Neanderthals
Eugène Morin, Véronique Laroulandie
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0032856
Abstract: In Africa and western Eurasia, occurrences of burials and utilized ocher fragments during the late Middle and early Late Pleistocene are often considered evidence for the emergence of symbolically-mediated behavior. Perhaps less controversial for the study of human cognitive evolution are finds of marine shell beads and complex designs on organic and mineral artifacts in early modern human (EMH) assemblages conservatively dated to ≈100–60 kilo-years (ka) ago. Here we show that, in France, Neanderthals used skeletal parts of large diurnal raptors presumably for symbolic purposes at Combe-Grenal in a layer dated to marine isotope stage (MIS) 5b (≈90 ka) and at Les Fieux in stratigraphic units dated to the early/middle phase of MIS 3 (60–40 ka). The presence of similar objects in other Middle Paleolithic contexts in France and Italy suggest that raptors were used as means of symbolic expression by Neanderthals in these regions.
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