Comparative Analysis of Control Techniques for PWM Rectifiers in Grid Connected Distributed Generation Systems Based on VOC and DPC

This paper presents Virtual flux based and Voltage based control schemes for PWM rectifiers in grid connected distributed generation systems from renewable sources are presented. In particular, the so-called Voltage Oriented Control (VOC), Direct Power Control (DPC), two DPC based techniques to minimize the Common Mode (CM) emissions called DPC-EMC1 and DPC-EMC2 set up by the authors and their versions based on virtual flux. All the described techniques have been implemented using MATLAB/Simulink® (Classic version 8.2 Release name (R2013b)) and compared with each other. Theoretical background with results of simulations is provided. The advantages and disadvantages of the individual control strategies are documented

Molecular diagnostic assay for pre-harvest detection of Tilletia indica infection in wheat plants

The current study describes a new diagnostic method for the rapid and accurate detection of Tilletia indica, the pathogen accountable for causing Karnal bunt (KB) disease in wheat. This method uses quantitative real-time polymerase chain reaction (qPCR) and a primer set derived from glyceraldehyde 3-phosphate dehydrogenase (GAPDH) gene of T. indica to identify the presence of the pathogen. The qPCR assay using this primer set was found highly sensitive, with a limit of detection (LOD) value of 4 pg of T. indica DNA. This level of sensitivity allows for the detection of the pathogen even in cases of different growth stages of wheat, where no visible symptoms of infection on the wheat plants can be seen by naked eyes. The study also validated the qPCR assay on ten different wheat cultivars. Overall, this study presents a valuable molecular tool for rapid, specific and sensitive detection of KB fungus in wheat host. This method has practical applications in disease management, screening of wheat genotypes against KB and can aid in the development of strategies to mitigate the impact of Karnal bunt disease on wheat production

The downside of repeated ties: syndicated capital investments

My dissertation develops a conceptual framework to study the largely unrecognized negative side effects or social costs of repeated ties with the same partners and partners’ social characteristics. Drawing on insights from the literatures on social networks, prestige and endorsements, learning, expertise and small groups, I suggest that the costs of repeated ties with the same partners are manifest by a bias in partner search, evaluation and selection; inadequate monitoring of familiar partners; and the adoption of suboptimal, insufficiently adapted routines developed during prior exchanges. I ultimately argue that these costs can be high enough to outweigh the benefits of repeated ties partially or even completely. I further argue that the level of cohesion in the network in which the actors and their partners are embedded, and the degree of similarity between them will moderate these costs. I also explore the effects of highly sought after partner characteristics such as their prestige/status and prior experience, on the likelihood of success of the partnership. I test the predictions of my theory on a longitudinal dataset consisting of the population of nearly 1,300 startups that received first round investments from syndicates of venture capital (VC) firms during the period 1997 to 2001. As predicted, I find that the likelihood of a syndicate’s success is related to the number of prior ties between syndicate members in an inverted U-shaped manner and that the costs associated with repeated ties are accentuated by partner homogeneity. I also find that the likelihood of the syndicate’s success decreases with an increase in the level of cohesion in the syndicate and the prior experience of the members. Finally, I find that the likelihood of success increases at a decreasing rate as syndicate members’ prestige increases. These findings make a number of contributions to research on strategy and organizational theory, primary among which is to further understanding of the negative effects of social networks. The study highlights the importance of considering the costs of prior ties in addition to their benefits when making partner selection decisions, particularly in contexts characterized by high levels of reciprocity between partners.Managemen

Barking Up The Wrong Tree? An Accountability Theory Perspective On The Effects Of Board Decision Monitoring On Ceo Experiential Learning

In this paper, we develop an accountability theory perspective (Tetlock, 1985; 1992; Lerner & Tetlock, 1999) on CEO-board relations that identifies, and provides noteworthy insights into, previously unexplored issues related to board effectiveness. Our conceptual frame focuses not on how boards might prevent managers from behaving badly , but rather on how they might impact a potentially equally significant managerial shortcoming, CEOs\u27 failure to learn as much as they might from prior strategic decisions. Beyond sensitizing us to a likely link between boards and executive learning that is not contemplated by prevailing theory, an accountability theory perspective suggests a focus on a critical subset of director behaviors that we label board decision monitoring , and define as the intensity and vigor with which directors demand explanations and justifications for CEOs\u27 strategic decisions. Our theory argues that, generally speaking, board decision monitoring will enhance executives\u27 capacities for learning from similar decisions made in the past. However, our theory departs from convention by specifying a range of conditions that are likely to reduce the benefits of intense monitoring. We further consider how, at the highest level of these contingency factors, intense monitoring might ultimately interfere with learning. Thus, our theory suggests at least the potential for a largely unexplored dark side to intense monitoring of firm CEOs by boards of directors

Getting Them To Think Outside The Circle: Corporate Governance, Ceos\u27 External Advice Networks, And Firm Performance

This article contributes to the social networks literature by examining how corporate governance factors influence CEOs\u27 external advice-seeking behaviors. We incorporate insights from social networks research into an agency theory perspective to predict, and demonstrate empirically, that governance factors recommended by agency theory increase CEOs\u27 tendencies to seek out advice contacts who are likely to offer perspectives on strategic issues that differ from their own; these advice-seeking behaviors ultimately enhance firm performance. Accordingly, this article also contributes to the corporate governance literature by describing how and why CEOs\u27 advice networks mediate the effects of governance factors on firm performance. Copyright of the Academy of Management, all rights reserved

Gut microbiota disparities between active Crohn's disease and healthy controls: A global systematic review

Purpose: Crohn's disease (CD) is challenging to manage. It has been suggested that modifying the gut microbiota could be a treatment strategy. We performed this systematic review to compare the gut microbiota between active CD and healthy controls. Results: The family Enterobacteriaceae and genus Bacteroides were increased in active CD compared to controls in 13 and 8 studies, respectively. The family Oscillospiraceae and genus Faecalibacterium decreased in active CD vs controls in 12 and 10 studies, respectively. Conclusion: Specific bacteria were associated with the microbiomes of active CD patients versus controls, offering insights into potential microbial targets for CD treatments