Optimal Performance of Dynamic Particle Swarm Optimization Based Maximum Power Trackers for Stand-Alone PV System Under Partial Shading Conditions

One of the important tasks for increasing the efficiency of photovoltaic (PV) system is the development and improvement of the maximum power point tracking algorithms (MPPT). These MPPT algorithms lead to the ability to catch efficiently the global maximum power point of the partially shaded PV array. One of these trackers is the particle swarm optimization (PSO) algorithm which is one of the Soft computing techniques. The conventional PSO based trackers have many advantages such as the simplicity of hardware implementation and independence from the installed system. The actual problem of the practical application of PSO is the determination of its parameters to ensure high effectiveness of extracting the global MPP. Analysis of scientific papers devoted to the PSO algorithm has shown that there is currently no methodology for the optimal parameters' selection of PSO algorithm based maximum power trackers for the PV system. This paper aims to create a convenient and reasonable method for choosing the optimal parameters of the PSO algorithm, taking into account the topology and parameters of the DC-DC converter and the configuration of solar panels. A new method for selecting the parameters of a buck converter connected to a battery has been presented. The optimal value of the sampling time for the digital MPP controllers, providing their maximum performance; has been determined based on a new methodology. Matlab/Simulink software package is used as the main research tool. The prominent outcomes identify that the modified PSO and its designed parameters best meet the requirements of the MPPT controller for the PV system

Oral health knowledge and quality of life among Kuwait University students

PLEASE NOTE: This work is protected by copyright. Downloading is restricted to the BU community: please click Download and log in with a valid BU account to access. If you are the author of this work and would like to make it publicly available, please contact [email protected] (MSD)--Boston University, Henry M. Goldman School of Dental Medicine, 2006 (Dental Public Health).Includes bibliographical references: leaves 48-49.Aim: To evaluate and quantify the oral health knowledge and opinions of Kuwait University students. The objectives are to assess Oral Health Knowledge (OHK) and Oral Health-Related Quality of Life (OHRQOL) among Kuwait University students, and to evaluate the outcome of the School Oral Health Program in improving oral health knowledge, opinions, and quality of life for those who were part of the School Oral Health Program (SOHP), compared to those who were not part of the SOHP. Methods: A self-administered questionnaire was distributed to 500 students in different colleges in Kuwait University from May to July 2005. Three-hundred students completed the questionnaire anonymously. Demographics, Oral hygiene habits and behavior, OHK and OHRQOL questions were included. Descriptive statistics, bivariate analysis, linear regression models were perfomed using Epi, Info, Version 3.3.2 and SAS Version 8.2. Results: Three hundred (60%) completed the questionnaire. Of these, eighty-seven percent were female. Almost two-thirds reported their parents had college or higher educational level, 80% studied in public schooIs, and over 80% lived in Hawally and Capital regions of Kuwait. Fifty-five percent reported that they had a dental clinic in their school and one-third visited SOHP centers. Two-thirds reported they have good oral health, and almost 50% said they did not have any dental diseases. Most of the respondents (73%) visited the dentist in the last 12 months, and the most common reason for visiting the dentist was pain (30%). Only 20% saw their dentist for a regular dental exam. Brushing twice a day was the most common method (72%), with a large majority (78%) using fluoridated toothpaste. Sixty percent were not able to identify any dental disease correctly. Oral health knowledge was correct in some aspects such as the role of sugar and bacteria in dental caries and the role of fluoride in caries prevention. Oral health knowledge was poor in other areas since only 20% knew that soft drinks cause dental caries or that parents could transmit bacteria to their children. Overall, the respondents showed good OHRQOL, where half of the participants reported their oral health did not interrupt their life in the last three months because of oral problems. Only 5% reported that their social, physical or psychological part of their life has been affected by their oral health problems in the last three months. Linear regression model for OHK showed that having knowledge was related to good to excellent oral health, having dental disease, and brushing twice or more a day. OHRQOL model showed that mother’s college or higher education level, and those who reported having no dental diseases positively influence OHRQOL. Surprisingly there was no differences seen in either OHK or OHRQOL between SOHP attendees and those who did not go to SOHP. Conclusion: These findings indicate that although students seem to have good OHK in some aspects, there is sti11 room for improvement, especially in the area of enumerating oral diseases, knowing the role of fluoride in caries prevention and the role of routine dental check-up visits, to prevent oral diseases or at least decrease dental emergency visits. In general there are no differences in OHK and OHRQOL between SOHP attendees and those who were not SOHP attendees. Since oral health promotion is a large part of SOHP policy, better methods to improve oral health knowledge and behaviors should be implemented

Knowledge, Attitude, and Barriers to Fluoride Application as a Preventive Measure among Oral Health Care Providers

Objective. To investigate the knowledge, attitude, and possible barriers to fluoride application among oral health-care providers in Kuwait. Methods. A validated self-administered questionnaire was distributed to a random sample of 291 dentists. The questionnaire included four categories: dentists’ characteristics, knowledge of and attitude towards fluoride application, factors influencing decision-making on prescription of fluoride, and the clinician’s perception of own knowledge. Means, group differences, and logistic regression were calculated. Results. 262 completed the questionnaire (response rate of 90%). Half of the participants (49%) reported that water fluoridation is the best method for caries prevention in children. Majority of the participants (80%) acknowledged that topical fluoride prevents dental caries, but only 40% frequently use it in their practices. Fear of overdose was a concern in 57% of the participants. About 31% believed that caries is a multifactorial disease and cannot be prevented. In addition, 32% of the dentists who thought caries is multifactorial and cannot be prevented stated that restorations take precedence over preventive therapy. Conclusion. Despite the participants being in favor of topical fluoride application and believing in its effectiveness, certain barriers were apparent such as knowledge deficiencies, products labelling flaw, and lack of participation in effective continuing educational activities

Severe Hyperparathyroidism Versus Parathyroid Carcinoma: A clinical dilemma

No clinical or laboratory data allow a preoperative diagnosis of parathyroid carcinoma and only occasionally does a definitive finding differentiate an adenoma from a carcinoma. We present a case of primary hyperparathyroidism presenting with severe elevation of parathyroid hormone and serum calcium as well as complications. We go on to discuss the case in the light of a literature review. The severity of the elevation of the parathyroid hormone, other biochemical alterations, the presence of skeletal and renal complications and of a neck mass should alert the clinician to a possible parathyroid carcinoma. Radical surgery is the only effective therapy for parathyroid carcinoma, and should always be performed if a preoperative suspicion is entertained

Looking perfect: Instagram use in a Kuwaiti cultural context

<p>This study surveys 539 Arab university students to examine gender motivational differences in Instagram use, exploring the Self-Perfectionist Personality concept and usage activities that best predict a <i>Self-Presentation</i> motive on Instagram. While both genders utilized Instagram mainly for <i>Entertainment</i>, they varied on the priority of other motives. Females were less likely to have public accounts, post personal pictures, and disclose personal information. Also, self-perfectionists of both genders excessively edited their personal pictures before posting them and were more likely to use Instagram for <i>Self-Presentation</i>. Outcomes are discussed in the light of the influences of culture and gender roles in Kuwait.</p

America, America: national identity, presidential debates, and national mood

In their public messages, United States politicians often invoke America in an attempt to unite citizens and build electoral coalitions. Such an emphasis is particularly common in presidential debates, which are climactic "media events" late in campaigns for the White House, when candidates take questions from journalists and citizens while addressing millions of voters. We analyzed the connection between (a) candidates' highlighting of national identity in presidential debates and (b) mass public opinion since 1960. We expected and found that (a) candidates increased their emphasis on the nation during times of heightened national uncertainty, (b) Democratic presidential candidates invoked the nation more often than Republican candidates, and (c) comparisons across elections among incumbents suggest that national uncertainty was more important than partisan identity in eliciting invocations of the nation