661 research outputs found

    A minimal HIV-AIDS infection model with general incidence rate and application to Morocco data

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    We study the global dynamics of a SICA infection model with general incidence rate. The proposed model is calibrated with cumulative cases of infection by HIV-AIDS in Morocco from 1986 to 2015. We first prove that our model is biologically and mathematically well-posed. Stability analysis of different steady states is performed and threshold parameters are identified where the model exhibits clearance of infection or maintenance of a chronic infection. Furthermore, we examine the robustness of the model to some parameter values by examining the sensitivity of the basic reproduction number. Finally, using numerical simulations with real data from Morocco, we show that the model predicts well such reality.Comment: This is a preprint of a paper whose final and definite form is with 'Statistics Opt. Inform. Comput.', Vol. 7, No 2 (2019). See [http://www.IAPress.org]. Submitted 16/Sept/2018; Revised 10 & 15/Dec/2018; Accepted 15/Dec/201

    ORGANIZATIONAL LEARNING MECHANISMS IN SOHAR UNIVERSITY

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    PurposeThe objective of the study is to critically examine the mechanisms of organizational learning in Sohar University and to identify the relationship between stages of organizational learning and mechanisms of organizational learning and to examine the effectiveness and the nurturance of the pedagogical practices.Design/methodology/approachThe study was conducted with 76 employees from all the departments of Sohar University, who were selected on a simple random sampling basis and were contacted through a well-defined questionnaire. FindingsThe study reveals that the employees of Sohar University are encouraged to attend external programs and seminars on new developments have been organized and the university prepares detailed plans reflecting contingency approaches. The study also confirmed that there is no relationship between demographic factors (Gender, age, qualification and teaching experience) and the Organizational learning. The study also reveals that there is an association between the Innovations, Implementation and Organization learning.Practical ImplicationsThe study has thrown light on the organizational learning process, which is the key driver in innovating, implementing and stabilizing.Research limitationsThe study was restricted to the academic staff from all the faculties of Sohar University. Many of them did not understand the concept. So the researcher has to explain them in detail before furnishing the detailed questionnaire.Social ImplicationsThe study can be extended to other colleges and universities in Oman so that the accuracy of the tools and techniques of organizational learning can be ascertained. This will induce high transmission goals to equip and uplift the participants in a positive and creative contribution.Originality/valueOnly a very few have examined the impact of Organization Learning in the Universities of Oman, and it is a first-hand study of its kind.

    Discriminative Parameter Estimation for Random Walks Segmentation

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    The Random Walks (RW) algorithm is one of the most e - cient and easy-to-use probabilistic segmentation methods. By combining contrast terms with prior terms, it provides accurate segmentations of medical images in a fully automated manner. However, one of the main drawbacks of using the RW algorithm is that its parameters have to be hand-tuned. we propose a novel discriminative learning framework that estimates the parameters using a training dataset. The main challenge we face is that the training samples are not fully supervised. Speci cally, they provide a hard segmentation of the images, instead of a proba- bilistic segmentation. We overcome this challenge by treating the opti- mal probabilistic segmentation that is compatible with the given hard segmentation as a latent variable. This allows us to employ the latent support vector machine formulation for parameter estimation. We show that our approach signi cantly outperforms the baseline methods on a challenging dataset consisting of real clinical 3D MRI volumes of skeletal muscles.Comment: Medical Image Computing and Computer Assisted Interventaion (2013

    Crystal structure of 5,11-dihydropyrido-[2,3-b][1,4]benzodiazepin-6-one

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    Acknowledgements The authors thank Andreas Lorbach and Todd B. Marder (Institute of Inorganic Chemistry, Wuerzburg University) for the data collection and structure solution. We appreciate the financial support provided to NMR by the Deutscher Akademischer Austauschdienst (DAAD). Thanks are also due to the Deutsche Forschungsgemeinschaft for financial support (SFB 630, Recognition, Preparation and Functional Analysis of Agents against Infectious Diseases, project A1).Peer reviewedPublisher PD

    Improvement of hydration products for self-compacting concrete by using magnetized water

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    Magnetized water (MW) is one of the most effective and economical ways to improve the properties of self-compacting concrete (SCC). Therefore, the aim of this study is to improve the fresh, mechanical, and microstructural properties of SCC using MW. For this purpose, a total of 12 mixes were produced with silica fume (SF) content (5% and 10% by weight of cement), and the mixing water passed through a permanent magnetic field (with a strength of 1.4 T) for 50, 100, and 150 cycles. Tests were performed for fresh properties (Slump flow, T50cm, V-funnel, and L-box), for mechanical properties (compressive, flexural, and tensile strength), and for microstructure properties (SEM, EDX, and TGA/DTG). The optimum result in compressive strength was achieved in the mix M8 using 5% silica fume and 150 cycles of MW. For fresh properties, the mix M4 using 150 cycles without SF had the workability enhanced by 11% compared to the control mix, and SEM and EDX tests indicated that SCC mixes prepared with MW had more C-S-H, less CH, and were denser. In addition, TGA/DTG analysis showed that the rate of hydration of mix M8 was reached by 61% at 28 days.

    Tipos de tensiones mecánica y térmica en la primera etapa de la pala del rotor de una turbina

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    Introduction: In this paper, the simulation of first stage of low pressure turbine for Nasiriya Power Plant was done to study the aerodynamic characteristic of steam along stage at load 70 MW, also the two types of mechanical stresses on the first stage rotor blade were studied in this paper. Materials and Methods:The material of blade was X20Cr13 stainless steel grade 1.4021. The first type of mechanical stresses which due to the steam pressure on the blade was analyzed. The seconds types of mechanical stresses that the centrifugal stresses on the blade. The AutoCAD software code was used for modeling the turbine stage, the dimensions and operational conditions were obtained practically from Nasiriya power plant and ANSYS (15.0) software was used to make simulate the turbine. Results and Discussion: The results showed that maximum steam velocity occurred at trailing edge of stationary blades and leading edge of rotating blades, also the maximum stresses occurred at the leading edge and trailing edge of root blade, the stresses due to the effect of centrifugal force is larger than the stresses due the pressure force. Conclusions: The maximum deformation occurred at tip of blade and minimum deformation depicted at root of blade

    The power fractional calculus: first definitions and properties with applications to power fractional differential equations

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    Using the Laplace transform method and the convolution theorem, we introduce new and more general definitions for fractional operators with non-singular kernels, extending well-known concepts existing in the literature. The new operators are based on a generalization of the Mittag–Leffler function, characterized by the presence of a key parameter p. This power parameter p is important to enable researchers to choose an adequate notion of the derivative that properly represents the reality under study, to provide good mathematical models, and to predict future dynamic behaviors. The fundamental properties of the new operators are investigated and rigorously proved. As an application, we solve a Caputo and a Riemann–Liouville fractional differential equation.Fundação para a Ciência e a Tecnologia (FCT), grant number UIDB/04106/2020 (CIDMA).publishe

    The Empirical Evidence for Telemedicine Interventions in Mental Disorders

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    Problem and Objective: This research derives from the confluence of several factors, namely, the prevalence of a complex array of mental health issues across age, social, ethnic, and economic groups, an increasingly critical shortage of mental health professionals and the associated disability and productivity loss in the population, and the potential of telemental health (TMH) to ameliorate these problems. Definitive information regarding the true merit of telemedicine applications and intervention is now of paramount importance among policymakers, providers of care, researchers, payers, program developers, and the public at large. This is necessary for rational policymaking, prudent resource allocation decisions, and informed strategic planning. This article is aimed at assessing the state of scientific knowledge regarding the merit of telemedicine interventions in the treatment of mental disorders (TMH) in terms of feasibility/acceptance, effects on medication compliance, health outcomes, and cost. Materials and Methods: We started by casting a wide net to identify the relevant studies and to examine in detail the content of studies that met the eligibility criteria for inclusion. Only studies that met rigorous methodological criteria were included. Necessary details include the specific nature and content of the intervention, the research methodology, clinical focus, technological configuration, and the modality of the intervention. Results: The published scientific literature on TMH reveals strong and consistent evidence of the feasibility of this modality of care and its acceptance by its intended users, as well as uniform indication of improvement in symptomology and quality of life among patients across a broad range of demographic and diagnostic groups. Similarly, positive trends are shown in terms of cost savings. Conclusion: There is substantial empirical evidence for supporting the use of telemedicine interventions in patients with mental disorders.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140291/1/tmj.2015.0206.pd
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