Journal of African Christian Biography: v. 1, no. 5

A publication of the Dictionary of African Christian Biography with U.S. offices located at the Center for Global Christianity and Mission at Boston University. This issue focuses on: 1. William Wadé Harris, Prophet-Evangelist of West Africa: His Life, Message, Praxis, Heritage, and Legacy. 2. William Wadé Harris. 3. Recent Print and Digital Resources Related to Christianity in Africa

Nonlinear Discrete Observer for Flexibility Compensation of Industrial Robots

This paper demonstrates the solutions of digital observer implementation for industrial applications. A nonlinear high-gain discrete observer is proposed to compensate the tracking error due to the flexibility of robot manipulators. The proposed discrete observer is obtained by using Euler approximate discretization of the continuous observer. A series of experimental validations have been carried out on a 6 DOF industrial manipulator during a Friction Stir Welding process. The results showed good performance of discrete observer and the observer based compensation has succeed to correct the positioning error in real-time implementation.ANR COROUSS

A Novel Approach for Simplification of Industrial Robot Dynamic Model Using Interval Method

This paper proposes a new approach to simplify the dynamic model of industrial robot by means of interval method. Due to strong nonlinearities, some components of robot dynamic model such as the inertia matrix and the vector of centrifugal, Coriolis and gravitational torques, are very complicated for real-time control of industrial robots. Thus, a simplification algorithm is presented in this study in order to reduce the computation time and memory occupation. More importantly, this simplification is suitable for arbitrary trajectories in whole robot workspace. Furthermore, the method devotes to finding negligible inertia parameters, which is useful for robot model identification. A simulation has been carried out on a test trajectory using a 6-DOF industrial robot model, and the results have shown good performance and effectiveness of this method.ANR COROUSS

Experimental External Force Estimation Using a Non-Linear Observer for 6 axes Flexible-Joint Industrial Manipulators

This paper proposes a non-linear observer to estimate not only the state (position and velocity) of links but also the external forces exerted by the robot during Friction Stir Welding (FSW) processes. The difficulty of performing this process with a robot lies in its lack of rigidity. In order to ensure a better tracking performance, the data such as real positions, velocities of links and external forces are required. However, those variations are not always measured in most industrial robots. Therefore, in this study, an observer is proposed to reconstruct those necessary parameters by using only measurements of motor side. The proposed observer is carried out on a 6 DOF flexible-joint industrial manipulator used in a FSW process.ANR-2010-SEGI-003-01-COROUSSO, French National Agenc

Methods and techniques for bio-system's materials behaviour analysis

In the context of the rapid development of the research in the biosystem structure materials domain, a representative direction shows the analysis of the behavior of these materials. This direction of research requires the use of various means and methods for theoretical and experimental measuring and evaluating. PhD thesis "Methods and means for analyzing the behavior of biosystems structure materials" shall be given precedence in this area of research, aimed at studying the behavior of polymeric materials and composites biosystems structure and in particular the skeletal structure biosystem. Therefore, it is developed a specific method of research based on the development of theoretical models for the prediction of the mechanical, thermal and machinability properties of these materials. There are used Moldflow, Solidworks and Ansys software types. In order to validate the theoretical research were designed and conducted experimental research on the mechanical properties and the behavior of the polymeric biomaterials represented by ABS, UHMWPE, HDPE, PA, PC, PET, PP, PP_GF-30% and composite materials with polymeric thermoplastic matrixes from the skeletal biosystem¿s structure. In order to analyze the theoretical and experimental correlations, the experimental data were processed using the statistical analysis software programs SPSS v17, v8 Origin, Palisade Decision Tools. In conclusion, the thesis represents a technic, scientific and efficient support for analyzing the behavior of the new polymeric and composite materials from the biosystem structure.Mitu, LG. (2014). Methods and techniques for bio-system's materials behaviour analysis [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/35445TESI

Journal of African Christian Biography: v. 3, no. 1

A publication of the Dictionary of African Christian Biography with U.S. offices located at the Center for Global Christianity and Mission at Boston University. This issue focuses on: 1. “Creole Saga”: The Gambia’s Liberated African Community in the 19th Century: The Stories of J. A. B. Horton, G. C. Nicol, J. R. Maxwell, and J. D. Richards by Asi Florence Mahoney. Introduction by Gabriel Leonard Allen. 2. The Contribution of Daniel William Alexander to the Birth and Growth of Eastern Orthodoxy in East Africa. 3. Biographies by Stephan Hayes and Louise Pirouet. Introduction by Fr. Evangelos Thiani. 4. Recent Print and Digital Resources Related to Christianity in Africa

Landscape-scale approaches for integrated natural resource management in tropical forest landscapes

Integrated natural resource management (INRM) helps resource users, managers, and others to manage resources sustainably by considering, reconciling, and synergizing their various interests and activities. Although many social and environmental problems have to be tackled at a range of scales to be resolved successfully, INRM has particular relevance at the landscape level at which the interests of local people first intersect those of the outside world. We propose eight guidelines for building successful INRM programs: focus on multiscale analysis and intervention; develop partnerships and engage in action research; facilitate change rather than dictating it; promote visioning and the development of scenarios; recognize the importance of local knowledge; foster social learning and adaptive management; concentrate on both people and their natural resources, including biodiversity; and embrace complexity. Reviewing these guidelines in the light of experiences from three separate studies shows that most are being done, though more as a product of happenstance than design. The guidelines form a mutually reinforcing framework for building INRM, primarily through empowering local stakeholders to be more articulate advocates and active participants in their own development and conservation efforts