Power sharing strategy using H∞ controller between two distributed generation sources in islanded mode

This project addresses the problem of the primary controller of parallel-connected inverters in AC microgrid, which is operated in islanded mode. Voltage and frequency power sharing controller techniques are commonly used for sharing loads. However, this non-communication power sharing control technique has a disadvantage, where the frequency and voltage deviations are severe during a sudden load change. Currently, it can be fixed by using the communication-based secondary level. Therefore, the concept of non-communication network is needed for the DGs with fast restoration of voltage and frequency in order to maintain the stability and sensitivity of the islanded system. This project aims to develop a robust distributed H ∞ power sharing strategy to overcome the problem of restoration. The new controller would be able to enhance the performance and give a more reliable performance for power sharing, voltage and frequency restoration. Moreover, this project mainly focuses on the mathematical modelling of parallel-connected inverters, where the eigenvalues technique of the electric network is used to predict the stability of the islanded condition by applying eigenvalue technique. The proposed H ∞ power sharing control has established a condition for power sharing among the DGs and restores the voltage and frequency. This controller has shown the robustness effect in order to restore voltage and frequency and to satisfy the system performance. Finally, this H ∞ controller with robust and dynamic response is tested in islanded mode configuration, which has two DGs with identical power ratings connected to several local loads at the point of common coupling. The proposed robust controller’s theoretical concept is validated by using MATLAB Simulink, and it is compared with the conventional and existing secondary power sharing strategies that are also applied at the same electrical system. As result, the proposed controller can achieve better steady state performance and fast restored frequency within 0.002 s with rise time 0.05s while compared to 0.13 s rise time for existing secondary controller. Maximum overshoot is also reduced during the suddenvi load changed and good tracking performance efficiency by 95% as compared to the 90% efficiency of existing secondary controller and 85% conventional controller. Thus, it is able to restore voltage and frequency to nominal values and enhances power sharing according to inverter rating

Condom Use and Consistency Among Teen Males

This Child Trends study finds that any type of formal sex education is linked with higher levels of condom use at teen males' first sexual experience. However, one in five teen males (ages 15-19) did not receive formal sex education about either abstinence or contraception before having sex for the first time. The study, published in the October 2008 issue of the Journal of Adolescent Health and summarized in this fact sheet, examines how multiple dimensions of teen males' lives are associated with condom use and consistency. Among the findings: --Having an older partner or a casual partner is linked to less condom use. Nearly one-fourth of teen males had an older recent partner and more than one-third were in a casual relationship with their first sexual partner. --Older teen males and those in longer relationships are less likely to use condoms. This was true even after controlling for whether their partner used a contraceptive method. --Positive attitudes about using condoms are linked to actual use. Teen males who disagree with the ideas that condoms reduce physical pleasure and that it would be embarrassing to discuss condom use with a new partner have higher levels of condom use and consistency. --Seven in ten teen males reported using a condom at their first and at their most recent sexual experience, but fewer reported using condoms consistently. Just one-half of sexually active teen males reported using a condom consistently with their most recent sexual partner

Predictors of Nutritional Status Among U.S. Adults

The purpose of this study was to more fully understand the reasons underlying poor nutritional status among adults in the United States (US) and to provide research findings that can be used to develop programs and policies to help improve nutritional status in the US. The National Health and Nutrition Examination Survey (NHANES) dataset and the correlational quantitative study design were used to explore the associations between food security, household smoking, and demographics and nutritional status. The social ecologic theory, specifically the social ecology of health as it relates to interventions, was used as the study\u27s theoretical framework. The results of the regression analyses conducted found statistical significance with respect to the effect of food security on nutritional status. In addition, significant moderation of the relationship by the demographic variable race/ethnicity was found using additional regression models, which incorporated interaction effects. Additionally, correlational analysis was conducted between independent and dependent variables in order to determine whether multicollinearity was present, and strong multicollinearity was found with food security but not with living in a smoking house. Public health professionals should focus on these findings when creating new programs and policies. Doing so may help to improve the nutritional status of the U.S. population

Audience Preferences and Popular Program Patterns on News Channels in Karachi

This research aims to study the factors that influence the viewership of leading Pakistani News Channels including Dunya, Samaa, Express, Geo and ARY. It examines the impact of content, presentation style, channel positioning and anchors, alongside overall news viewing patterns, on the public image of the identified news channels and their viewership with focus on Express News. Following a qualitative research approach, a representative sample of 51 news viewers is identified and interviewed, with a proportionate weight to geographical areas and socio-economic classification of the audience, based on recent Census and People’s meter, an audience measurement tool. The respondents are investigated through a comprehensive questionnaire, comprised both closed and open-ended questions. This study focuses on three categories of viewers including Express News Viewers, Express-News Lapsers and Competitive Channels Viewers. One-on-one interviews reflect the mindset and viewing patterns of news channels’ audience. It is also instrumental to highlight the factors that hinder Express-News ratings against its competing channels. Findings of the study indicate that the programme content, presentation style, and cable positioning of news channels significantly influence its viewership that results in the quantum of recall for Express-News, and how its viewership and ratings are presumably affected by the very factors

Image-based Material Editing

Photo editing software allows digital images to be blurred, warped or re-colored at the touch of a button. However, it is not currently possible to change the material appearance of an object except by painstakingly painting over the appropriate pixels. Here we present a set of methods for automatically replacing one material with another, completely different material, starting with only a single high dynamic range image, and an alpha matte specifying the object. Our approach exploits the fact that human vision is surprisingly tolerant of certain (sometimes enormous) physical inaccuracies. Thus, it may be possible to produce a visually compelling illusion of material transformations, without fully reconstructing the lighting or geometry. We employ a range of algorithms depending on the target material. First, an approximate depth map is derived from the image intensities using bilateral filters. The resulting surface normals are then used to map data onto the surface of the object to specify its material appearance. To create transparent or translucent materials, the mapped data are derived from the object\u27s background. To create textured materials, the mapped data are a texture map. The surface normals can also be used to apply arbitrary bidirectional reflectance distribution functions to the surface, allowing us to simulate a wide range of materials. To facilitate the process of material editing, we generate the HDR image with a novel algorithm, that is robust against noise in individual exposures. This ensures that any noise, which would possibly have affected the shape recovery of the objects adversely, will be removed. We also present an algorithm to automatically generate alpha mattes. This algorithm requires as input two images--one where the object is in focus, and one where the background is in focus--and then automatically produces an approximate matte, indicating which pixels belong to the object. The result is then improved by a second algorithm to generate an accurate alpha matte, which can be given as input to our material editing techniques

CRIMES AND VIOLENCE IN TELEVISION NEWS AND ITS EFFECTS ON THE MENTAL HEALTH OF VIEWERS IN PAKISTAN

This research aims to study the psychological effects of thenews coverage of violent crimes on television viewers in Pakistan. Itseeks to investigate how such coverage is likely to influence the mentalhealth of the audience. Total 392 news viewers from diverse age, genderand professional backgrounds are sampled following the nonprobabilityconvenience and voluntary sampling techniques. Thesampled participants are investigated over a period of six months (i.e.from June 2016 to December 2016) through a carefully-designedquestionnaire based on the Mental Health Inventory (MHI-38) to assessthe effects of excessive and concentrated news viewing. The findingsof the study indicate that there is significant positive correlationbetween the frequency and duration of mediated exposure to real-lifeviolence and mental distress which is measured in terms of anxiety,depression and emotional instability

Characterisation of 2D and 3D oral keratinocyte cultures

Oral keratinocyte behaviour were analysed in two and three dimensional cultures of an immortalised human H400 cellline and primary rat keratinocytes (PRKs) using a novel method of quantitative microscopy, RT-PCR data and immunohistochemistry profiles. Monolayer cultures were established in high and low calcium media at different cell densities and analysed prior to generating 3D organotypic cultures (OCs) onde-epidermalised dermis (DED), polyethylene terephthalate porous membrane (PET) and collagen gels for up to 14 days.H400 and PRKs proliferation in monolayer cultures was greater in low calcium medium compared with high calcium medium.Gene expression analysis indicated that adhesion and structural molecules including E-cadherin, plakophilin, desmocollin-3, desmogleins-3 and cytokeratins-1, -5, -6, -10, -13 were up-regulated by days 6 and 8 compared with day 4in high calcium medium. Immunohistochemical profiles and gene expression data of OCs on DED recapitulated those of normal oral epithelium. The final thickness of OCs as well as the degree of maturation/stratification was significantly greater on DED compared with other scaffolds used. Quantitative microscopy approaches enabled unbiased architectural characterisation of OCs and the ability to relate stratified organotypic epithelial structures to the normal oral mucosa. H400 and PRK OCs on DED at the air liquid interface demonstrated similar characteristics in terms of gene expression and protein distribution to the normal tissue architecture

Music influences on health compromising behaviors

Considering the vast number of youth that participate in sexual behavior and start using illicit drugs at a young age, it is imperative to investigate the prevalence of media filled with both subliminal and blatant messages about drugs and sexuality. It is hypothesized that lyrical content of music and the content and imagery of music videos will contain conscious messages about drug and alcohol use, and sexual behaviors. Content analysis that used the frequency method determined the amount of sexual and drug messages within five songs from each artist. Additionally, it is postulated that participants who frequently listen to specific music genres, regularly watch music videos, and stay up-to-date on music artists will be more likely to engage in health compromising behaviors compared to participants who are not as involved with popular music. Applying the bio-ecological systems perspective, it is hypothesized that the negative influences of music (i.e., exosystem) can be minimized or heightened by microsystem (i.e., family, friends) influences as well as internal characteristics of participants (i.e., personality). A series of analyses of variance were conducted to determine if there was a relationship between exposure to lyrical content and drug and sexual behavior. Linear regression analysis was conducted to determine if public image of the artist was correlated to health compromising behavior. Overall results indicate that a relationship between music genre preferences - though the combination of lyrical content, the public image of artists, and the imagery in music videos - and illicit drug usage and sexual behavior

Can Small Farmers Survive?: Problems of Commercializing the Milk Value Chain in Pakistan

Milk in Pakistan is infused with the self-understanding of a nation. British colonial administrators laid the modern-day foundations of the country’s structure through land grants to small farmers. In an agricultural country where nearly forty percent of the population remains food insecure, rearing animals is a way of life in the rural areas where milk remains an important source of animal protein. Selling the daily surplus that families don’t consume is a significant source of earnings for cash poor families – and here an unprecedented change is taking place within dairy management and milk procurement systems. The scale of this change is significant as is its ability to connect even the smallest of dairy farmers to the milk buying habits, shaped by sophisticated marketing campaigns, of middle-class buyers in the country’s burgeoning cities. The significant changes underway are the result of the actions of large multinational and national companies - including the entry of the commercial arm of the military in the commercialization of the milk value chain - paying cash to small farmers. These operations, which may at first seem symbiotic, in connecting rural sellers to urban buyers, are in fact placing significant pressures on farmers to increase the size of their holdings as well as to improve their breeding stock by moving towards improved (meaning imported) higher yielding cattle varieties. While national and provincial governments with the support of international development partners promote the dairy sector as contributing to rural, economic and national development, I argue that a strategy driven by efficiency will ultimately lead to the demise of those very same small livestock and agricultural farmers it aims to uplift. This is because the logic of commercializing the milk value chain through the operations of large Milk Procurement and Marketing Companies (MPMC’s) and the pressures to increase milk yields and herd sizes requires consolidation and financing – options that are mostly available to richer and larger farmers. Is modernized milk collection already moving beyond its reliance on collecting milk from dispersed small farms? The unfolding pressures carry with them the effects of increasing demand for all inputs, including consolidated land, water and feed operations which in turn have significant implications for small farmers, animals and the environment. With small farmers reliant on the income from the sale of milk that ties them to a system that may come to no longer need them, can we foretell the demise of small farms? I suggest that these insights are particularly relevant for the study of rural, economic, social, national and international development