83 research outputs found
Recommended from our members
Global Stability Analysis of Healthy Situation for a Coupled Model of Healthy and Cancerous Cells Dynamics in Acute Myeloid Leukemia
In this paper we aim to study the global stability of a coupled model of healthy and cancerous cells dynamics in healthy situation of Acute Myeloid Leukemia. We also clarify the effect of interconnection between healthy and cancerous cells dynamics on the global stability The interconnected model is obtained by transforming the PDE-based model into a nonlinear distributed delay system. Using Lyapunov approach, we derive necessary and sufficient conditions for global stability for a selected equilibrium point of particular interest (healthy situation). Simulations are conducted to illustrate the obtained results
Recommended from our members
Dynamical Behavior of Biological Healthy Steady State in Leukemia Using a New Leukemic & Healthy Stem Cells Cohabitation Model with Distributed Delay
Acute Myeloid Leukemia (AML) treatment protocol from clinical point of view, aims to maintain a normal amount of healthy cells and to eradicate all malignant cells. This particular objective is biologically qualified as a positive healthy situation. In this paper, we give sufficient and necessary conditions for the global stability of such a healthy situation. To this end, we first propose a new distributed delay model of AML. The latter is an improvement of an existing delayed coupled model describing the dynamics of hematopoesis stem cells in AML. We modify the PDEs equations and transform them into a set of distributed delay equations. The proposed model is more suitable for biological phenomena than constant delay models as the proliferation time differs from a cell type to another. Furthermore in the proposed model, we consider the sub-population of cells that have lost their capacity of self-renewal and became progenitors. In second, we derive sufficient and necessary conditions for the global stability of healthy steady state. For this, the positivity of the obtained model and sequences of functions theory are used to construct new Lyapunov function candidates. Finally, we conduct numerical simulations to show that the obtained results complete and generalize those published in the literature
Power management and control strategies for off-grid hybrid power systems with renewable energies and storage
This document is the Accepted Manuscript of the following article: Belkacem Belabbas, Tayeb Allaoui, Mohamed Tadjine, and Mouloud Denai, 'Power management and control strategies for off-grid hybrid power systems with renewable energies and storage', Energy Systems, September 2017. Under embargo. Embargo end date: 19 September 2018. The final publication is available at Springer via https://doi.org/10.1007/s12667-017-0251-y.This paper presents a simulation study of standalone hybrid Distributed Generation Systems (DGS) with Battery Energy Storage System (BESS). The DGS consists of Photovoltaic (PV) panels as Renewable Power Source (RPS), a Diesel Generator (DG) for power buck-up and a BESS to accommodate the surplus of energy, which may be employed in times of poor PV generation. While off-grid DGS represent an efficient and cost-effective energy supply solution particularly to rural and remote areas, fluctuations in voltage and frequency due to load variations, weather conditions (temperature, irradiation) and transmission line short-circuits are major challenges. The paper suggests a hierarchical Power Management (PM) and controller structure to improve the reliability and efficiency of the hybrid DGS. The first layer of the overall control scheme includes a Fuzzy Logic Controller (FLC) to adjust the voltage and frequency at the Point of Common Coupling (PCC) and a Clamping Bridge Circuit (CBC) which regulates the DC bus voltage. A maximum power point tracking (MPPT) controller based on FLC is designed to extract the optimum power from the PV. The second control layer coordinates among PV, DG and BESS to ensure reliable and efficient power supply to the load. MATLAB Simulink is used to implement the overall model of the off-grid DGS and to test the performance of the proposed control scheme which is evaluated in a series of simulations scenarios. The results demonstrated the good performance of the proposed control scheme and effective coordination between the DGS for all the simulation scenarios considered.Peer reviewedFinal Accepted Versio
Production and characterization of murine monoclonal antibodies against Haemophilus parasuis and study of their protective role in mice
La problématique complexe de l'accompagnement entrepreneurial et de PME par des Organisations Non Marchandes soumises au contact inter-culturel
International audience« If you want to sell what the client buys, you should see the world through the client’s eyes ». Dans quelle mesure cette règle évidente du Marketing et du Management par la Valeur est-elle vraie pour les organisations non marchandes soumises au contact inter-culturel, qu’il s’agisse d’organismes d’accompagnement entrepreneurial d’immigrants en France ou de structures internationales de support au développement du secteur privé (en particulier, la petite et moyenne entreprise) dans les pays en transition ? Afin de répondre à cette question, nous nous appuyons sur des observations ethno-méthodologiques et sur des recherches - actions réalisées au sein et pour le compte de telles organisations. Sur ces bases, notre réponse à cette question suggère a priori que ces organisations et leurs membres ont à réaliser simultanément un double travail d’appropriation. L’appropriation porte, en effet, au moins autant sur les outils classiques du management que sur la variable inter-culturelle. Nous montrons en effet que dans le cas de l’accompagnement de créateurs d’entreprises immigrés, le problème de leur entrée dans la zone de cohérence des 3 E inhérent à tout processus de création se trouve compliqué par un arbitrage interculturel supplémentaire qui en retour, interroge l’accompagnant. Par la suite, nous sommes conduits à décrire la relation entre le porteur de projet et son accompagnateur comme une relation de co-appropriation, l’accompagnant devant s'approprier à la fois le projet, et l'identité culturelle et la stratégie d'acculturation du porteur tandis que ce dernier doit s'approprier les règles de gestion de son environnement de création. Cette co-appropriation constitue alors une condition nécessaire pour que la relation Accompagnant-Porteur soit véritablement efficace
La problématique complexe de l'aide au développement du secteur privé par les Organisations Non Marchandes soumises au contact inter-culturel
International audience« If you want to sell what the client buys, you should see the world through the client’s eyes ». Dans quelle mesure cette règle évidente du Marketing et du Management par la Valeur est-elle vraie pour les organisations non marchandes soumises au contact inter-culturel, qu’il s’agisse d’organismes d’accompagnement entrepreneurial d’immigrants en France ou de structures internationales de support au développement du secteur privé dans les pays en transition ? Afin de répondre à cette question, nous nous appuyons sur des observations ethno-méthodologiques et sur des recherches - actions réalisées au sein et pour le compte de telles organisations. Sur ces bases, notre réponse à cette question suggère a priori que ces organisations et leurs membres ont à réaliser simultanément un double travail d’appropriation. L’appropriation porte, en effet, au moins autant sur les outils classiques du management que sur la variable inter-culturelle. Nous montrons en effet que dans le cas de l’accompagnement de créateurs d’entreprises immigrés, le problème de leur entrée dans la zone de cohérence des 3 E inhérent à tout processus de création se trouve compliqué par un arbitrage interculturel supplémentaire qui en retour, interroge l’accompagnant. Par la suite, nous sommes conduits à décrire la relation entre le porteur de projet et son accompagnateur comme une relation de co-appropriation, l’accompagnant devant s'approprier à la fois le projet, et l'identité culturelle et la stratégie d'acculturation du porteur tandis que ce dernier doit s'approprier les règles de gestion de son environnement de création. Cette co-appropriation constitue alors une condition nécessaire pour que la relation Accompagnant-Porteur soit véritablement efficace
Complex problem of the direct enterprise development support by non-profit organisations subjected to the intercultural contact
« If you want to sell what the client buys, you should see the world through the client’s eyes!... » To what extend this evident Marketing and Value Management rule is true for the Non-for-Profit Organisations of Enterprise Development Support subjected to the inter-cultural contact, whether it would be an accompanying agency for the immigrant entrepreneurs in France or an international enterprise development mission in a transitional economy country? To bring some elements of reply to this question, the authors are basing on the ethno-methodological observations, as well as on the action-research, realised in frame and for the account of such organisations. As a result, they suggest that these organisations and their staff members are to realise a simultaneous double appropriation effort. Indeed, the appropriation endeavour is necessary in regards with both, the classical management tools usage but also the intercultural variable. It is shown that, in the case of the Accompanying to the immigrant enterprise creators in France, their interaction with the Accompanying structure appears to be complicated by a supplementary intercultural psychological arbitration. This process, in turn, influences the accompanying agent. Subsequently, the relation between the Entrepreneur and the Support Provider could be described as a co-appropriation relation: the support provider has to appropriate the entrepreneur’s project, his cultural identity and his Acculturation strategy, while the entrepreneur is to appropriate the corresponding management tools of enterprise creation. Such co-appropriation constitutes a necessary condition for the true efficacy of the above Provider-Entrepreneur relation. Thus, this intercultural support relationship is modelled in terms of a dynamic matrix that is presently used as a management tool at one of the French entrepreneurial support devices (Boutiques de Gestion). The authors then discuss its possible transposition on the international aid programs for Enterprise (SME) Development Support in the transitional countries and the consequences of such transpositio
- …