We investigate the gap in math and science achievement of thirdand fourth-graders who live with a single parent versus those who live with two parents in 11 countries. The United States and New Zealand rank last among the countries we compare in terms of the equality of achievement between children from single-parent families and those from two-parent homes. Following a multilevel analysis, we ...

objective: regardless of three decades of implementation of family planning program in nepal, need of family planning services is largely unmet. systematic studies, evaluating the impact of family program on several ethnic groups of nepal has not been carried out in large scale. this study sheds light on the investigation of, whether the use of contraceptives varies among different ethnic group...

1.1 HARMONICS IN ELECTRICAL SYSTEMS ............................................................................................ 1 1.2 CONVENTIONAL TWO-LEVEL AND THREE-LEVEL VOLTAGE SOURCE INVERTER ............................... 2 1.3 MULTILEVEL VOLTAGE SOURCE INVERTER..................................................................................... 5 1.3.1 Diode-Clamped Multilevel Inverter...

this paper gives a detailed analysis of direct torque control (dtc) strategy in a five-level drive and proposes a 24-sector switching table. the overvoltage problem due to high dv/dt is reduced compared to the 12-sector dtc. using all vectors leads to better flexibility and reduces speed oscillations. simulation and experimental results for a 3kva prototype confirm the proposed solutions. a tms...

The study of databases through formal logic has not only enabled efficient proof procedures to be developed for query evaluation and integrity checking, but it has also resulted in the development of more intelligent and powerful database management systems. Despite all these advances, a logic for reasoning in a multilevel environment or a logic programming system for multilevel environments do...

Many large nonlinear optimization problems are based upon a hierarchy of models, corresponding to levels of discretization or detail in the problem. Optimization-based multilevel methods—that is, multilevel methods based on solving coarser versions of an optimization problem— are designed to solve such multilevel problems efficiently by taking explicit advantage of the hierarchy of models. The ...