Numerical Approach for the Computation of Preliminary Post-Newtonian Corrections for Laser Links in Space

Two systems of Earth-centered inertial Newtonian orbital equations for a spherical Earth and three systems of post-Newtonian nonlinear equations, derived from the second post-Newtonian approximation to the Earth Schwarzschild field, are used to carry out a performance analysis of a numerical procedure based on the Dormand-Prince method for initial value problems in ordinary differential equations. This procedure provides preliminary post-Newtonian corrections to the Newtonian trajectories of middle-size space objects with respect to space-based acquisition, pointing, and tracking laser systems, and it turns out to be highly efficient. In fact, we can show that running the standard adaptive ode45 MATLAB routine with the absolute and relative tolerance, TOLa = 10−16 and TOLr = 10−13, respectively, provides corrections that are final within the eclipses caused by the Earth and close to final during the noneclipse phases. These corrections should be taken into account to increase the pointing accuracy in implementing the space-to-space laser links required for ablation of designated objects or communications between space terminals.

OVERVIEW REGARDING THE MAIN GUIDELINES, STANDARDS AND METHODOLOGIES USED IN PROJECT MANAGEMENT

<p>This article tries to present the basic elements of the main guidelines, international standards and methodologies (methods) used in project management. In this category we include: the PMBOK®Guide (elaborated by the Project Management Institute), the PRINCE method (elaborated by the British Office of Government Commerce), the ISO 21500:2012 standard (elaborated by the International Organization for Standardization) etc. At the basis of these guidelines, standards and methodologies stay a great practice experience. Depending on the particularity and type of project, of management philosophy and culture of the organization that runs the project, we can choose to apply a certain guide, standard or methodologies (methods). The stated goal of these guidelines, standards and methodologies (methods) is to provide an optimum framework, the best practice for manage project to success. Applying these guidelines, standards and methodologies (methods) may be prerequisite project success, being a necessary but not always sufficient.</p>

OVERVIEW ABOUT THE MANAGEMENT OF THE HUMAN RESOURCE IN PROJECTS

The purpose of this study is to emphasize the main aspects regarding the management of the human resource in projects. This study tries to present in the comparative manner, different approaches of several guidelines, international standards and methodologies regarding the management of the human resource in projects (the PMBOK ® Guide elaborated by the Project Management Institute and the PRINCE method elaborated by the British Office of Government Commerce). The PMBOK® Guide describes four elements (processes) of human resource management: human resource planning, acquire project team, develop project team and manage project team. The PMBOK approach regarding human resource management is focused on utilizing the people involved in the project in the best way. According the PRINCE method the management of the human resource is focused on the roles and responsibilities of the human resource within the project. In this standard, the responsibilities are viewed like a roles. Everybody involved in the project can have one or more roles and a role can be fulfilled by several persons.

OVERVIEW ABOUT PROJECT QUALITY MANAGEMENT

The purpose of this study is to emphasize the main aspects regarding project quality management. This study tries to present in the comparative manner, different approaches of the main guidelines, international standards and methodologies regarding project quality management (the PMBOK ® Guide elaborated by the Project Management Institute, the PRINCE method elaborated by the British Office of Government Commerce etc.). The PMBOK® Guide describes three elements (processes) of quality management: quality planning (plan quality management), quality assurance (perform quality assurance) and quality control (control quality). The PMBOK approach regarding project quality management is that quality management must lead to achieving and validating project requirements. According the PRINCE method the quality is one of the six variables involved in any project. The PRINCE approach regarding project quality management considers that strategy in this field must lead to achieving just the level of quality needed to achieve in the project and not to ensuring the best quality.