We study how fast-fashion retailers should manage their inventories when customer demand is impacted by inventory scarcity. We characterize the optimal stocking levels for a single fast-fashion retailer under an economic order quantity (EOQ) model. We show that under this EOQ model, the fast fashion retailer benefits from deliberate understocking. We conclude that deliberate understocking may stimulate demand for a fast-fashion retailer by creating a sense of scarcity.

Perturbation Iteration Method was developed recently to find approximate analytical solutions for algebraic, differential and other type of equations. The method combines the perturbation methods and the iteration methods to converge analytically to the real solution. Perturbation Iteration Method is the general name for various Perturbation Iteration Algorithms which vary depending on the number of correction terms in the perturbation expansion and the highest order derivatives in the Taylor expansions. Theorems on the implementation of Perturbation Iteration Methods to ordinary differential equations are posed and proven. The structure of the equation, the order of the perturbation parameters in the system hides clues about the implementation of the right algorithm. Theorems therefore may guide the applied researchers to select a suitable algorithm from the beginning. The link between the classical perturbation solutions and the Perturbation Iteration Algorithms are also discussed via a theorem. Example problems are given for the applications of each theorem.

This article uses Green's function and Banach fixed point theorem to study the existence of solutions for boundary value problems of a class of fractional order differential equations with p-Laplacian operators.

et rendre service à la communauté, le secteur de l'enseignement supérieur est un bon canal de vulgarisation du concept. Dans cette recherche, il a donc été question de comprendre si les universités et les instituts supérieurs sont en même de prêcher par de bons exemples ; d'où le sujet de cet article : « Pratiques de DD des EES au Burundi ». Ainsi, l'étude s'est fixée un double objectif : (1) relever les pratiques durables existantes au sein des EES au Burundi, (2) comprendre les raisons qui encouragent les EES au Burundi à initier des pratiques de DD malgré leur caractère non obligatoire. Étant donné le nombre élevé d'EES, un échantillon de 15 institutions (publiques et privées) a été effectué selon la méthode d'échantillonnage aléatoire stratifié. Pour chaque institution, le Recteur (Directeur Général) ou son Représentant, a fourni les informations utiles grâce aux entretiens semidirectifs et au questionnaire. Les résultats mettent en évidence que les pratiques de DD résultent essentiellement des pressions internes et externes (isomorphisme coercitif). En plus, les pratiques sociales sont plus nombreuses que les pratiques économiques ou environnementales.

This paper proposes an algorithm to find an optimal mixture that is as close as possible to an ideal solution, starting from a set of elements (items) described by a set of variables (features). This class of optimization problems can be tackled through traditional approaches belonging to the field of operations research (OR) or even through meta-heuristics techniques belonging to the field of artificial intelligence (AI). In order to present an artificial intelligence perspective, this paper uses a genetic algorithm (GA) model which proves its consistency through the comparison with a linear programming (LP) solver on a set of 8-items 5-features experiments. Results show that the proposed GA converges towards the global optimum and provides competitive results.

Natural resource stocks are drastically shrinking and the contemporary debate on depletion of reserves highlights their crucial role over time. This paper deals with the management of exhaustible resources when recycling and extraction are employed, as well as the short-term effects of the economic transition towards circularity on consumption and welfare. Mathematical modeling may support effective plans for maximizing social welfare and protecting the environment. Concerning the production of a certain good, an optimal control model is studied to allocate labor between mining and recycling over a finite time horizon. A suitable scrap value function allows for reducing waste and maintaining natural stock in the forthcoming future. Well-posedness of the problem is proved and some qualitative features of the optimal solution are stated.

The statistical modeling of the problem of poverty is a major challenge given Burundi's economic development managment system. Innovative economic optimization systems are widely needed to face the problem of the dynamic of the poverty in Burundi. The Burundian economy shows an inflation rate of1.5% in 2018 for the Gross Domestic Product growth real rate of 2.8% in 2016. This research concerns the FDP ++ R 2023A Algorithm for Performance Improvment of Burundi management system. The SATINOV management sciences and decision support in Africa. The aim is to find a management system model that contributes to solving the problem of poverty in Burundi. This model solves an optimization problem combining the variables of production, consumption, budget, human resources and available raw materials. Scientific modeling and optimal solving of the poverty problem show the tools for measuring poverty rate and determining various countries' poverty levels when considering advanced knowledge for performance improvment of Burundi management system.

Quaterns are a new measure of rotation. Since they are defined in terms of rectangular coordinates, all of the analogue trigonometric functions become algebraic rather than transcendental. Rotations, angle sums and differences, vector sums, cross and dot products, etc., all become algebraic. Triangles can be solved algebraically. Computer algorithms use truncated infinite sums for the transcendental calculations of these quantities. If rotations were expressed in quaterns, these calculations would be simplified by a few orders of magnitude. This would have the potential to greatly reduce computing time. The archaic Greek letter koppa is used to represent rotations in quaterns, rather than the traditional Greek letter theta. Because calculations utilizing quaterns are algebraic, simple rotation in the first two quadrants can be done "by hand" using "pen and paper." Using the approximate methods outlined towards the end of the paper, triangles may be approximately solved with an error of less than 3% using algebra and a few simple formulas.

This study was conducted to investigate reasons encountered in understanding concept in the study of general chemistry by undergraduate students in Burundi. Burundian University students were compared on (i) Teacher not leaving time for questions, (ii) no opportunity for group studies, (iii) syllabus wideness, and the using of a projector' as a reason for concept difficulty in the study of general chemistry. A Difficult Concepts in General Chemistry Questionnaire (DCGCQ) was administered to 817 undergraduate students to collect quantitative data for the study while a Difficult Concepts in General Chemistry Interview Guide (DCGCIG) was the qualitative instrument used to elicit responses from the 8 randomly selected participants from 2 public universities and 2 private universities. Among 23 concepts investigated, the results showed that pH and octet rule are perceived as the most difficult concepts in the study of chemistry. On the basis of chi-square test, a significant difference was noticed for concepts such as Octet rule, Electronegativity, Quantum number, Chemical equilibration, 2 François Nitereka et al. Concentration, and Oxidation number. The reasons that cause difficulties in the study of general chemistry among the students of the universities in Burundi were largely attributed to group work, wideness of syllabi, and the use of projector in the teaching of general chemistry. Appropriate remediating measures have been suggested to ease the difficulties in the study of chemistry in Burundian universities.

The manuscript should be prepared using LaTeX or Word processing system, basic font Roman 12pt size. The papers should be in English and typed in frames 14 x 21.6 cm (margins 3.5 cm on left and right and 4 cm on top and bottom) on A4-format white paper or American format paper. On the first page leave 7 cm space on the top for the journal's headings. The papers must have abstract, as well as subject classification and keywords. The references should be in alphabetic order and must be organized as follows: