DESIGN OPTIMIZATION OF RESONANT DC-DC CONVERTERS

Resonant DC/DC converters are the class of converters, which have L-C resonant tank serving as a major part of the power conversion process. The fundamental concept of the resonant converter is that the circulating energy in an L-C resonant circuit is manageable by changing the operating frequency, and therefore the converter can condition the input power to the desired output voltage. The development in power conversion technology is steady demand for high power efficiency and high power density. A high efficiency is achieved by using series resonant converter (SRC) topology. It may operate in either continuous or discontinuous conduction modes. After exploring the advantages of using a resonant converter, the series resonant converter is implemented. Increasing the frequency is desirable for power converters operation. However, the switching losses will increase by increasing the frequency of operation. Hence, the efficiency of the system reduces drastically. In order to reduce switching losses and increasing high frequency operation, a series resonant converter has been developed. The resonant tank of SRC consists of a resonant capacitor and a resonant inductor connected in series. The output load resistance is in series with the resonant tank and the impedance of the resonant tank is a function of the switching frequency, and hence the voltage across the output impedance can be modulated by the switching frequency

Examining The Effects Of Parasocial Interaction And Identification With Social Media Influencers On Collaborating Brands

The thesis explores the phenomenon of social media influencers, reveal their distinctive features, explain how followers develop relationships with them and clarify how and why a cooperation with influencers could be effective. Based on parasocial interaction theory and social influence theory, the study examines the associations between parasocial interaction and identification with a social media influencer along with the effect it carries towards the collaborating brand; in terms of advocacy, purchase intention and brand image. Antecedents of parasocial interaction with social media influencers have been investigated in terms of awareness, credibility, and physical attractiveness. The data were collected using an online questionnaire from 252 respondents. The findings suggest that the three predictor variables; awareness, credibility physical attractiveness significantly influence parasocial interaction. Parasocial interaction affects identification which in turn exert significant impact on advocacy, purchase intention and perceived image. The findings have essential managerial implications, as such most importantly it proves that identification with social media influencer has a different level of effect on collaborating brands, depending on the fore sought marketing outcome

A Risk Assessment Framework for Inter-Organizational Knowledge Sharing

Internet-based Information, Communication and Collaboration technologies are making it easier for organizations and knowledge workers to collaborate across organizational boundaries. However, it is necessary for organizations to monitor, regulate and build appropriate security mechanisms in collaboration systems to prevent loss of strategic knowledge and competitive advantage. In this paper, we present a risk assessment framework that can help organizations identify valuable knowledge assets exposed through collaboration technologies, and assess the risk of knowledge loss, intellectual property leakage, and the subsequent loss of competitive advantage so that appropriate security mechanism can be designed to prevent such a loss. We present an illustrative scenario to demonstrate the feasibility of the framework, and describe a prototype decision support system for automating the risk assessment process

Distributed Model Management Systems: A Proposal for an Ontology-Based Approach

While managers in today’s global business environments are thrusting for swifter, more flexible, and scalable decision support, technical challenges pertaining to model sharing arise due to the limited capabilities of current model representation techniques. In this research, we propose that ontologies can improve model representation and thus support sophisticated model management capabilities such as model integration and composition in distributive collaborative environments. The proposed solution extends SMML and builds upon previous literature in the semantic web to provide a model representation language that is capable of capturing model structure as well as semantics

Malaria microscopy in primary health care centers in Khartoum State, Sudan: external quality assurance study

Background: Adequate diagnosis of Malaria is achieved by detection and identification of malaria parasites through examination of Giemsa’s stained blood films by competent personnel.Objective: To identify the competency of laboratory personnel of the clinical laboratories attached to primary health care centres at Khartoum State- Sudan, by applying External quality assurance (EQA) slide check.Design: A cross-section and facility based study conducted during the period from October to December 2015.Setting: Primary health care centres at Khartoum State, Sudan.Subjects: The study enrolled 52 clinical laboratories.Result: For the EQA slides, there were 262 positive slides, 199 of them were P. falciparum and 63 were P. vivax. Study subjects achieved 213 true positive results and 204 true negative results, sensitivity and specificity were 81.3%, 79% respectively. For species detection, they reported 134 true positives and 54 true negatives for P. falciparum (sensitivity 84.8%, specificity 98%); and 55 true positive and 134 true negative P. vivax (sensitivity 98%, specificity 84%). False negative results tend to be obtained when parasite load in scanty (OR: 3.64), and is likely associated with P. falciparum (OR: 1.9).Conclusion: This study concluded that the quality of malaria microscopy for the study facilities was poor and the personnel were found of low competency. Poor infrastructure, heavy workload, and absence of training were among the factors that affect the competency of study personnel

A Framework for Assessing Knowledge Sharing Risks in Interorganizational Networks

Collaboration technologies are making it easier for organizations and knowledge workers to collaborate across organizational boundaries. However, it is necessary for organizations to monitor, regulate and build appropriate security mechanisms in collaboration systems to prevent loss of strategic knowledge and competitive advantage. In this paper, we present a risk assessment framework that can help organizations identify valuable knowledge assets that can be exposed through collaboration technologies, and help prioritize security strategies that can be used to secure the collaboration systems to prevent the loss of valuable knowledge assets. We present an illustrative case to demonstrate the feasibility of the framework, and discuss issues for future research

Supplier-initiated ingredient/component branding

Purpose: This paper aims to understand the process of initiating ingredient/component (IC) branding from the supplier's perspective. It proposes modeling entrepreneurial orientation (EO) as an antecedent factor and differentiation abilities (functional and reputational) as mediators. Investigating IC branding from the supplier's perspective is critical given the cost and risk associated with implementing such a strategy. Design/methodology/approach: A total of 5,254 manufacturing companies were screened to identify IC supplier firms that meet certain criteria. Survey data were collected from 77 top managers (Chief Executive Officers or Chief Marketing Officers) of IC supplier firms. The paper uses partial least squares structural equation modeling (PLS-SEM) and SPSS in analyzing data. Findings: The results indicate that IC branding is a complex strategy – one involving a number of steps that need to be taken in a specific order. More specifically, results indicate that IC branding starts with EO exerting a positive influence on IC functional differentiation ability (FDA). FDA facilitates reputational differentiation ability (RDA), which in turn encourages the supplier to initiate IC branding. Originality/value: This paper addresses an important gap by studying the process through, which suppliers initiate IC branding

Developing a semantic web-based distributed model management system: Experiences and lessons learned

Distributed model management systems (DMMSs) are decision support systems with a focus on managing decision models throughout the modeling lifecycle and across the extended enterprise. The advent and proliferation of web services and semantic web technologies offers the possibilities of sharing and reusing models in a distributed setting. This paper presents the design and implementation of a semantic web-based DMMS. Key lessons learned, technical and organizational issues encountered are summarized and directions for future research have been outlined. From a technical perspective, future research will need to explore the viability of tools specifically designed to facilitate the semantic annotation of models, specify and validate SA-SMML, and extend the white-box approach presented in this paper to other model types not amenable to structured modeling. From an organizational perspective, further research is needed in the areas of adoption issues and business models that would ensure the sustainable support for of such systems in the service enterprise

Combating Infant Mortality in Rural India: Evidence from a Field Study of eHealth Kiosk Imlementations

The United Nations’ Millennium Development Goals listed high infant mortality rates as a major problem in developing countries, especially in rural areas. Given the powerful information dissemination capabilities, information and communication technologies (ICTs) have been suggested as interventions to build infant care awareness and to modify healthcare behaviors. We examine how the use of one ICT intervention—specifically, eHealth kiosks disseminating authenticated and accessible medical information—can alleviate the problem of high infant mortality in rural India. We investigate how mothers’ social networks affect their use of eHealth kiosks, seeking professional medical care for their infants and, ultimately, infant mortality. Drawing on the social epidemiology and social networks literatures, we focus on advice and hindrance from both strong and weak ties as the conduit of social influence on mothers’ health-related behaviors for the care of their infants. Over a period of 7 years, we studied 4,620 infants across 10 villages where the eHealth kiosks were implemented along with support resources for proxy use. The results revealed that (1) eHealth kiosk use promotes seeking professional medical care and reduces infant mortality, (2) mothers are especially vulnerable to hindrance from both strong and weak ties as they choose to maintain the status quo of traditional infant healthcare practices (e.g., reliance on untrained personnel, superstitions, fatalism) in villages, and (3) advice from both strong and weak ties offers the potential to break down misplaced beliefs about infant healthcare practices and to develop literacy on seeking professional medical care. In contrast, in a comparative group of 10 neighboring villages, the reduction in infant mortality was not as pronounced and the effect of professional medical care in reducing infant mortality was lower. Our findings suggest that an ICT intervention can effectively address one of society’s most important problems (i.e., infant mortality) even in parts of the world with limited resources and deep suspicion of technology and change. Overall, we believe such an ICT intervention will complement other investments being made, including the facilitation of use (proxy use) and provision of professional medical facilities to reduce infant mortality