A NEW REDUCED SWITCH ZVS-PWM THREE-PHASE INVERTER

Dc-ac inverters convert a dc input voltage into a desired ac output voltage and are widely used in many industrial applications, including utility grid interfaces, motor drives, and wind energy systems. Because of their widespread use, there has been considerable interest to try to make them more efficient to conserve energy. One way of doing so is to reduce the losses that are generated by the switching of the inverter devices as they help convert the dc input voltage into an ac output. As a result, there has been considerable research into implementing inverters with so-called soft-switching - zero-voltage and zero-current switching techniques that make either the voltage across a switch or the current through it zero at the time of a switching transition (from on to off or off to on). Since the power dissipated in a switch is related to the amount of overlap of voltage and current during a switching transition, making either the switch voltage or switch current zero at this time can result in a significant reduction in switching losses. A new, reduced switch, zero-voltage switching (ZVS), three-phase dc-ac inverter is proposed in this thesis. The proposed inverter does not have the drawbacks that other previously proposed ZVS-PWM inverters have such as cost, increased conduction losses, the appearance of distortion in the output waveforms, and the lack of bidirectional operation capability. In the thesis, an extensive literature review of previously proposed soft-switched inverters is performed. The new inverter is then presented and its operation is explained in detail. The steady-state operation of the new inverter is analyzed and the results of the analysis are used to determine the converter\u27s steady-state characteristics. Based on these characteristics, a procedure for the design of the inverter is developed and then demonstrated with an example. Finally, the feasibility of the proposed converter and the validity of the analysis are confirmed with simulation results obtained from PSIM, a widely used, commercially available software simulation package for power electronic

Individual and household Life course explanation to entrepreneurial exit

Entrepreneurial exit, a critical stage in the entrepreneurial process, happens when the venture creators disengage from ownership control and decision-making authority of the firm they helped to create. Until now, academic research delineating the role of individual and household level resources in explaining exit (or otherwise) are relatively sparse. Of the limited research that provided a resource-based explanation to exit, hardly any research has investigated the influence of a multitude of different resources on the exit process and the subsequent decision to exit. Moreover, the impact of resources on the exit decision has only been studied at the individual level of analysis, despite evidence suggesting an inextricably intertwined relationship between the entrepreneur and the entrepreneurial households. Like the literature on entrepreneurship more broadly, research on entrepreneurial exit largely relies on cross-sectional data. Moving beyond the current understanding that exit is a dichotomous adverse event often equating to business failure, this research attempts to study the exit phenomenon factoring 'the time an individual takes to make the exit decision' to understand the influence of resources to determine (a) who experience an exit event (as opposed to who remain in business), (b) when in the business life course they make the exit decision, and (c) varying exit profiles for individuals. More specifically, this research study entrepreneurial exit from an entrepreneurial resource perspective, paying particular attention to human, financial and time as key resources to succeed, or otherwise, in the entrepreneurial journey. Drawing upon the UK longitudinal household survey (UKLHS), the thesis finds that a combination of human, financial and time resources determines one's faith in business. Overall, the author found support for the original thesis that household dynamics are highly influential in explaining the likelihood of the entrepreneur exiting from their business. The research findings also suggested that whether resources facilitate or constrain entrepreneurial practice, the effect of those resources in determining the exit outcome vary considerably. The study has made several contributions to the entrepreneurial exit literature. First, this research extends the current knowledge base on entrepreneurship and entrepreneurial exit with its exploration of the role of the resource in the entrepreneur's exit decision. Second, by adopting the entrepreneurial household as the framing context and positioning self-employed/business owners' resource base within the resource base of their household, this study has extended the resource definition to entrepreneur exit, which was earlier looked upon from an owner-centric perspective. Third, the life course analysis generated a more complex picture of entrepreneur exit than those provided by the existing literature. More specifically, by building the nuanced empirical understanding of resource demands, this research offers a broader conceptualisation of exit conditions that enable entrepreneurs and self-employed individuals to experience varying forms of exists. The typology that differentiates voluntary from non-voluntary and positive exit experience from negative experiences helps to respond to the call for reframing exit as an emergent opportunity-based decision rather than a one-off misfortune that often refers to in the exit literature as a ‘failure’ event. At the policy level, research findings challenge the policy discourse that anyone with access to minimum levels of resources and institutional support can start entrepreneurship by highlighting the importance of entrepreneurial capital. This research also challenges the policy understanding that household dynamics are separate from entrepreneurial/enterprise decisions, thereby overlooking the role of the household in entrepreneurial decisions, including exit

Sustainability of Self-Efficacy among Nascent Disable Entrepreneurs: A Case Study on Disable’s Home

The study has focused on practicality of self-efficacy theory, and how it helps to build confidence among the disables in building their career choice as entrepreneurs. For this we chose a case study approach on Disable’s home, which is a non- profit organization to provide support for disables. The study was conducted in two phases. First phase, from disable people’s perspective who were trainees in the Disable’s home. And second, from the Disable’s home’s perspective. Findings of the first phase suggest, in order to sustain self-efficacy with regard to career choice as entrepreneurs, not only institutional support is enough but other additional supports like social, financial, family supports  are important. In the second phase, it was observed that institution needs to be resourceful in order to provide proper support to the disables and embed self-efficacy among them.   JEL Classification Code:  M3

Sustainability of Self-Efficacy among Nascent Disable Entrepreneurs: A Case Study on Disable’s Home

The study has focused on practicality of self-efficacy theory, and how it helps to build confidence among the disables in building their career choice as entrepreneurs. For this we chose a case study approach on Disable’s home, which is a non- profit organization to provide support for disables. The study was conducted in two phases. First phase, from disable people’s perspective who were trainees in the Disable’s home. And second, from the Disable’s home’s perspective. Findings of the first phase suggest, in order to sustain self-efficacy with regard to career choice as entrepreneurs, not only institutional support is enough but other additional supports like social, financial, family supports are important. In the second phase, it was observed that institution needs to be resourceful in order to provide proper support to the disables and embed self-efficacy among them

An advanced data fabric architecture leveraging homomorphic encryption and federated learning

Data fabric is an automated and AI-driven data fusion approach to accomplish data management unification without moving data to a centralized location for solving complex data problems. In a Federated learning architecture, the global model is trained based on the learned parameters of several local models that eliminate the necessity of moving data to a centralized repository for machine learning. This paper introduces a secure approach for medical image analysis using federated learning and partially homomorphic encryption within a distributed data fabric architecture. With this method, multiple parties can collaborate in training a machine-learning model without exchanging raw data but using the learned or fused features. The approach complies with laws and regulations such as HIPAA and GDPR, ensuring the privacy and security of the data. The study demonstrates the method's effectiveness through a case study on pituitary tumor classification, achieving a significant level of accuracy. However, the primary focus of the study is on the development and evaluation of federated learning and partially homomorphic encryption as tools for secure medical image analysis. The results highlight the potential of these techniques to be applied to other privacy-sensitive domains and contribute to the growing body of research on secure and privacy-preserving machine learning

The Teaching of Singing in Meiji Period : Mainly on the contents of teaching

Additional file 3: Fig. S4. Spontaneous gp120 shedding from cell surface. The susceptibility of gp41 mutants to spontaneously shed gp120 was determined by flow cytometry and ELISA as described previously [79]. Briefly, culture medium of transiently transfected envelope expressing cells was exchanged for fresh medium containing Brefeldin A (BioLegend) and 0.2 % Sodium azide. Cells were then incubated for 15 h at 37˚C, 5 % CO2. (a) Level of envelope expression before and after incubation was compared by staining with 2G12. (b) Amount of gp120 released during incubation was determined by gp120 capture ELISA. As a positive control, cells expressing WT envelope was incubated with 20 µg/ml sCD4, which trigger gp120 shedding. Cells expressing SIV Env (SIV) and no Env (No Env) were used as negative control. The results are shown as the means ± standard errors of four replicas

The Diagnostic Utility of Induced Sputum Microscopy and Culture in Childhood Pneumonia.

BACKGROUND.: Sputum microscopy and culture are commonly used for diagnosing the cause of pneumonia in adults but are rarely performed in children due to difficulties in obtaining specimens. Induced sputum is occasionally used to investigate lower respiratory infections in children but has not been widely used in pneumonia etiology studies. METHODS.: We evaluated the diagnostic utility of induced sputum microscopy and culture in patients enrolled in the Pneumonia Etiology Research for Child Health (PERCH) study, a large study of community-acquired pneumonia in children aged 1-59 months. Comparisons were made between induced sputum samples from hospitalized children with radiographically confirmed pneumonia and children categorized as nonpneumonia (due to the absence of prespecified clinical and laboratory signs and absence of infiltrate on chest radiograph). RESULTS.: One induced sputum sample was available for analysis from 3772 (89.1%) of 4232 suspected pneumonia cases enrolled in PERCH. Of these, sputum from 2608 (69.1%) met the quality criterion of <10 squamous epithelial cells per low-power field, and 1162 (44.6%) had radiographic pneumonia. Induced sputum microscopy and culture results were not associated with radiographic pneumonia, regardless of prior antibiotic use, stratification by specific bacteria, or interpretative criteria used. CONCLUSIONS.: The findings of this study do not support the culture of induced sputum specimens as a diagnostic tool for pneumonia in young children as part of routine clinical practice