Estimation of finite mixtures using the empirical characteristic function

A problem which occurs in analyzing LANDSAT scenes is the problem of separating the components of a finite mixture of several distinct probability distributions. A review of the literature indicates this is a problem which occurs in many disciplines, such as engineering, biology, physiology and economics. Many approaches to this problem have appeared in the literature; however, most are very restrictive in their assumptions or have met with only a limited degree of success when applied to realistic situations. A proceudre is investigated with combines the k-L procedure of (Feurverger and McDunnough, 1981) with the MAICE procedure of (Akaike, 1974). The feasibility of this approach is being investigated numerically via the development of a computer software package enabling a simulation study and comparison with other procedures

Workplace implications for hurricane affected Gulf Coast region industrial companies

Organizational perspectives on the effects of disasters on employee behavior in the workplace and the related adjustments organizations make as a result of disaster are examined in this study. The survey instrument utilizes constructs of what organizations have done for their employees in regards to personal and family needs, business earnings and efforts to maintain continued business operations, philanthropy and volunteer activities, hiring and employee retention, safety and security, employee performance and activity, physical, mental or emotional effects, and human resource department adjustments or areas of coping as a result of Hurricane\u27s Katrina and Rita. Rebuilding timeframes for physically damaged organizations, what organizations could have done differently to better support their employees after the hurricanes, and whether organizational responses can be predicted from effects of the hurricanes are also explored. The survey was completed by 103 Gulf Coast ABC organizations. Factor analyses resulted in nine factors emerging as effects of the hurricanes on employees and nine emerging as organizational responses to those effects. For effects of the hurricanes, positive business effects was the highest reported mean and both negative employee reactions and employee withdrawal had the lowest reported mean. For organizational responses, management flexibility was the highest reported mean and increase in employee relations was the lowest. Based on multiple regressions, the following varying levels of predictive results emerged. Negative business effects was found to be a predictor of management flexibility, operational changes, employee recruiting and retention, employee turnover, greater Human Resources presence and involvement and increase in employee relation issues. Negative employee reactions were a predictor of employee turnover and increase in employee relation issues. Employee appreciation was a predictor of management flexibility, benefits and housing assistance, operational changes, safety and security adjustments, and greater Human Resources presence and involvement. Employee productivity effects was a predictor of benefits and housing assistance, philanthropy and volunteer activities, and employee recruiting and retention. Employee withdrawal was a predictor of safety and security adjustments, greater Human Resources presence and involvement and increase in employee relation issues and employee anxiety was a predictor of employee turnover

Effects of digital approximation in statistical estimation Final technical report

Digital approximation in statistical estimatio

Statistical design and data analysis techniques for space station application - An essay Final report

Application of statistical design and data analysis to configuration and development of space station experiments and missio

An introduction to the theory of generalized matrix invertibility

Literature survey on pseudo invertibility of matrice

A Practical Approach to the Secure Computation of the Moore-Penrose Pseudoinverse over the Rationals

Solving linear systems of equations is a universal problem. In the context of secure multiparty computation (MPC), a method to solve such systems, especially for the case in which the rank of the system is unknown and should remain private, is an important building block. We devise an efficient and data-oblivious algorithm (meaning that the algorithm\u27s execution time and branching behavior are independent of all secrets) for solving a bounded integral linear system of unknown rank over the rational numbers via the Moore-Penrose pseudoinverse, using finite-field arithmetic. I.e., we compute the Moore-Penrose inverse over a finite field of sufficiently large order, so that we can recover the rational solution from the solution over the finite field. While we have designed the algorithm with an MPC context in mind, it could be valuable also in other contexts where data-obliviousness is required, like secure enclaves in CPUs. Previous work by Cramer, Kiltz and Padró (CRYPTO 2007) proposes a constant-rounds protocol for computing the Moore-Penrose pseudoinverse over a finite field. The asymptotic complexity (counted as the number of secure multiplications) of their solution is $O(m^4 + n^2 m)$, where $m$ and $n$, $m\leq n$, are the dimensions of the linear system. To reduce the number of secure multiplications, we sacrifice the constant-rounds property and propose a protocol for computing the Moore-Penrose pseudoinverse over the rational numbers in a linear number of rounds, requiring only $O(m^2n)$ secure multiplications. To obtain the common denominator of the pseudoinverse, required for constructing an integer-representation of the pseudoinverse, we generalize a result by Ben-Israel for computing the squared volume of a matrix. Also, we show how to precondition a symmetric matrix to achieve generic rank profile while preserving symmetry and being able to remove the preconditioner after it has served its purpose. These results may be of independent interest

Exact steering law for pyramid-type four control moment gyro systems

An exact approach for gimbal steering based on generalised-inverse for a cluster of Control Moment Gyros (CMG) is presented, iteedback gains are calculated from analytical solutions of simplified model for desired closed-loop attitude dynamics of a satellite and corresponding angular momentum response of CMGs. It is highly desirable to be able to use full angular momentum workspace of CMG cluster for rapid slew manoeuvres. However, the troublesome internal elliptic singularities restrict the angular momentum workspace in most of the pseudo-inverse-based steering logics. Therefore, we propose a Generalised Inverse Steering Logic (GISL) different from Moore-Penrose inverse but exact unlike variants of Singularity Robust laws. The proposed method gives exact control while avoiding internal elliptic singularities and using full momentum capability of the CMG cluster. The important features of the proposed steering law are demonstrated by performing simulations. Copyright © 2006 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved