Sex differences in multiple dimensions of jealousy

The present study distributed surveys to 98 college students (31 freshmen, 28 sophomores, 25 juniors, and 14 seniors) to explore both evolutionary psychology and social cognitive theories on jealousy. To examine the relationship between sexes in multiple dimensions of jealousy, Pfeffer and Wong\u27s Multidimensional Jealousy Survey was given to measure cognitive, behavioral, and emotional jealousy (1989). There were no significant differences between sexes and any of the jealousy subscales. The traditional forced-choice scenario was given to see if there was a sex difference between emotional and sexual jealousy. As predicted, female participants reported that emotional jealousy was more distressing, while male participants reported that sexual jealousy was more distressing. The Subjective Happiness Scale by Lyubomirsky and Lepper (1997) was given to explore the relationship between happiness and jealousy, and a negative correlation was found. Participants also had their second and fourth digits measured on both hands to obtain a 2D:4D ratio. This ratio was used to see if there was a correlation between testosterone levels and jealousy. There was no significant difference found between digit length and jealousy. Future research could explore different types of jealousy between sexes and their responses in the event of jealousy

A Hysteresis Current-Regulated Control for Multi-Level Drives

Most multi-level converters are controlled through the use of voltage-source based control techniques such as space-vector modulation or multi-level sine-triangle modulation. However, in many applications such as field oriented drives, a high bandwidth current-source inverter based control is more desirable. In this paper, the concept of a multi-level hysteresis current-source control is set forth. The new control is experimentally verified using a four-level converter/induction motor drive system and the results are compared to a space vector modulation controller. A dynamic study involving a step change in current command demonstrates the controls high bandwidth

A New Walking Pattern SVM Technique for Five-Phase Motor Drives

As multi-phase motor drives become more popular and practical, new research in this area investigates potential advantages including lower torque ripple and better power density. The added dimensions of a multi-phase machine leads to a completely different operating nature than standard three-phase machines and merits research into new modulation methods. The five-phase and six-phase machines have been traditionally studied in the literature applying voltage-source modulation methods such as sine-triangle modulation and space- vector modulation for current harmonic elimination. Recent research of five-phase induction motor drives addressed nearest three vectors switching; which adds current harmonics but lowers torque ripple and considerably extends the drives voltage range. This paper introduces a new walking pattern SVM method which frees up the vector and sequence selection. The new method is demonstrated using detailed simulation and is shown to further reduce torque ripple

Extended Operation of Flying Capacitor Multilevel Inverters

Recent research in flying capacitor multilevel inverters (FCMIs) has shown that the number of voltage levels can be extended by changing the ratio of the capacitor voltages. For the three-cell FCMI, four levels of operation are expected if the traditional ratio of the capacitor voltages is 1:2:3. However, by altering the ratio, the inverter can operate as a five-, six-, seven-, or eight-level inverter. According to previous research, the eight-level case is referred to as maximally distended (or full binary combination schema) since it utilizes all possible transistor switching states. However, this case does not have enough per-phase redundancy to ensure capacitor voltage balancing under all modes of operation. In this paper, redundancy involving all phases is used along with per-phase redundancy to improve capacitor voltage balancing. It is shown that the four- and five-level cases are suitable for motor drive operation and can maintain capacitor voltage balance under a wide range of power factors and modulation indices. The six-, seven-, and eight-level cases are suitable for reactive power transfer in applications such as static var compensation. Simulation and laboratory measurements verify the proposed joint-phase redundancy control

Power Engineering Laboratory Facilities at the University of Missouri--Rolla

One of the significant niche areas at UMR is the area of electric power. For this reason UMR has invested in its power program over the years. The extent of this program ranges from power systems, motor drives, high-frequency effects in electric machines, acoustic noise of electric machines, FACTS device for electric utility applications, and naval propulsion power systems. The various laboratory facilities at UMR which supports these activities have been described in detail in this paper

Advanced Control and Analysis of Cascaded Multilevel Converters Based on P-Q Compensation

This paper introduces new controls for the cascaded multilevel power converter. This converter is also sometimes referred to as a ldquohybrid converterrdquo since it splits high-voltage/low-frequency and low-voltage/pulsewidth-modulation (PWM)-frequency power production between ldquobulkrdquo and ldquoconditioningrdquo converters respectively. Cascaded multilevel converters achieve higher power quality with a given switch count when compared to traditional multilevel converters. This is a particularly favorable option for high power and high performance applications such as naval ship propulsion. This paper first presents a new control method for the topology using three-level bulk and conditioning inverters connected in series through a three-phase load. This control avoids PWM frequency switching in the bulk inverter. The conditioning inverter uses a capacitor source and its control is based on compensating the real and reactive (P-Q) power difference between the bulk inverter and the load. The new control explicitly commands power into the conditioning inverter so that its capacitor voltage remains constant. A unique space vector analysis of hybrid converter modulation is introduced to quantitatively determine operating limitations. The conclusion is then generalized for all types of controls of the hybrid multilevel converters (involving three-level converter cells). The proposed control methods and analytical conclusions are verified by simulation and laboratory measurements