The oil and gas industry has a growing demand for electrically driven trains operated at variable speeds. Variable frequency electrical drives enable increased operational flexibility and energy efficiency. This is of great importance in applications requiring high power, such as gas compression. Load commutated inverters (LCIs) are one of the most widespread technologies for driving large gas ...

BACKGROUND Precise preoperative measurement of knee alignment is needed to calculate the accurate angle of correction at proximal tibia osteotomy for medial gonarthrosis. METHODS We performed a prospective study to compare the reproducibility of measuring the mechanical and anatomical axes. Thirty-two patients (32 knees) with medial compartment osteoarthritis to be treated with proximal tibia...

Debates about poverty relief and foreign aid often hinge on claims about how many poor people there are in the world and what constitutes poverty. Good measures of poverty are essential for addressing the world poverty problem. Measures of poverty require a basis for determining who is poor and a method of aggregation. Historically, the methods of aggregation were quite simple. The headcount in...

Measuring a quantum system can randomly perturb its state. The strength and nature of this back-action depends on the quantity which is measured. In a partial measurement performed by an ideal apparatus, quantum physics predicts that the system remains in a pure state whose evolution can be tracked perfectly from the measurement record. We demonstrate this property using a superconducting qubit...

there are instances in which it is desirable to determine relationships among fruit physical attributes. for example, fruits are often graded on the basis of size and projected area, but it may be more suitable and/or economical to develop a machine which grades by mass. therefore, a relationship between mass and dimensions or projected areas and/ or volume of fruits is needed. various grad...

Sliding mode is used in order to retain a dynamic system accurately at a given constraint and features theoretically-in nite-frequency switching. Standard sliding modes are known to feature nite time convergence, precise keeping of the constraint and robustness with respect to internal and external disturbances. Having generalized the notion of sliding mode, higher order sliding modes preserve ...