Control Group

About: Control Group is a based out in . It is known for research contribution in the topics: Control theory & Nonlinear system. The organization has 948 authors who have published 810 publications receiving 14379 citations.

Multilevel Inverter Topologies for Stand-Alone PV Systems

Abstract: This paper shows that versatile stand-alone photovoltaic (PV) systems still demand on at least one battery inverter with improved characteristics of robustness and efficiency, which can be achieved using multilevel topologies. A compilation of the most common topologies of multilevel converters is presented, and it shows which ones are best suitable to implement inverters for stand-alone applications in the range of a few kilowatts. As an example, a prototype of 3 kVA was implemented, and peak efficiency of 96.0% was achieved.

Chaotic sequences to improve the performance of evolutionary algorithms

Abstract: This paper proposes an experimental analysis on the convergence of evolutionary algorithms (EAs). The effect of introducing chaotic sequences instead of random ones during all the phases of the evolution process is investigated. The approach is based on the substitution of the random number generator (RNG) with chaotic sequences. Several numerical examples are reported in order to compare the performance of the EA using random and chaotic generators as regards to both the results and the convergence speed. The results obtained show that some chaotic sequences are always able to increase the value of some measured algorithm-performance indexes with respect to random sequences. Moreover, it is shown that EAs can be extremely sensitive to different RNGs. Some t-tests were performed to confirm the improvements introduced by the proposed strategy.

Management’s tone change, post earnings announcement drift and accruals

Abstract: This study explores whether the management discussion and analysis (MD&A) section of Forms 10-Q and 10-K has incremental information content beyond financial measures such as earnings surprises and accruals. It uses a classification scheme of words into positive and negative categories to measure the tone change in the MD&A section relative to prior periodic SEC filings. Our results indicate that short window market reactions around the SEC filing are significantly associated with the tone change of the MD&A section, even after controlling for accruals and earnings surprises. We show that management’s tone change adds significantly to portfolio drift returns in the window of 2 days after the SEC filing date through 1 day after the subsequent quarter’s preliminary earnings announcement, beyond financial information conveyed by accruals and earnings surprises. The drift returns are affected by the ability of the tone change signals to help predict the subsequent quarter’s earnings surprise but cannot be completely attributed to this ability. We also find that the incremental information of management’s tone change depends on the strength of the firm’s information environment.

Dietary fibre and satiety

Abstract: Summary Dietary fibres have different physiological effects and provide a variety of health benefits, including satiety. They are thought to impact on satiation (the satisfaction of appetite during feeding that marks the end of eating and satiety (inhibition of hunger as a result of having eaten), because of their properties of adding bulk (satiation) and producing viscosity (satiety). Pre-absorptive factors, such as gastric distention, and the work and time required for chewing are important for satiation. For this reason, the bulking and textural properties of fibre make it an attractive ingredient for enhancing satiation. Adding bulk to the diet with fibre will also reduce the energy density of the diet. Satiety signals are generated both pre- and post-absorptively. Viscous soluble fibres may be useful because they prolong the intestinal phase of nutrient digestion and absorption. This means that there is a longer time over which the macronutrients can interact with the pre-absorptive mechanisms of satiation and satiety, as well as prolong the time course of post-absorptive signals. Diets low in energy and fat, such as those typically recommended for obese people, are poorly satiating. Adding fibre to low-calorie/low-fat foods may enhance satiety, but because weight-loss meals are low in energy and fat, satiety is likely to be short lasting. Not all dietary fibre has an impact on satiety. We review types of dietary fibre, whole foods that contain dietary fibre, and published studies on the effect of these fibres on satiety.