This paper discusses the circuit theory aspects of power factor correction in switching converter circuits. The discussion begins with an examination of the requirement of power factor correction in dc=dc converters. Using the concept of zero-order converter circuits, su cient conditions for a dc=dc converter circuit to provide power factor correction are derived. The duality principle is appli...

In the conventional data envelopment analysis (DEA), it is assumed that all decision making units (DMUs) using the same input and output measures, means that DMUs are homogeneous. In some settings, however, this usual assumption of DEA might be violated. A related problem is the problem of textit{missing} textit{data} where a DMU produces a certain output or consumes a certain input but the val...

Introduction: Small field dosimetry is challenging for radiotherapy dosimetry. measurement of the output factor in the air and water (Sc, Scp) is one of the input parameters for commissioning of treatment planning systems and beam modeling. The aims of this study are to measured Sc,Scp for small fields with EBT2 and Ion chamber and design a appropriate mini-phantom for small fi...