Regularized and robust regression methods for high dimensional data

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University London.Recently, variable selection in high-dimensional data has attracted much research interest. Classical stepwise subset selection methods are widely used in practice, but when the number of predictors is large these methods are difficult to implement. In these cases, modern regularization methods have become a popular choice as they perform variable selection and parameter estimation simultaneously. However, the estimation procedure becomes more difficult and challenging when the data suffer from outliers or when the assumption of normality is violated such as in the case of heavy-tailed errors. In these cases, quantile regression is the most appropriate method to use. In this thesis we combine these two classical approaches together to produce regularized quantile regression methods. Chapter 2 shows a comparative simulation study of regularized and robust regression methods when the response variable is continuous. In chapter 3, we develop a quantile regression model with a group lasso penalty for binary response data when the predictors have a grouped structure and when the data suffer from outliers. In chapter 4, we extend this method to the case of censored response variables. Numerical examples on simulated and real data are used to evaluate the performance of the proposed methods in comparisons with other existing methods

The Ugly Bildungsromans- Subversion, dissent and assertion in Toni Morrison and Latifa al-Zayyat

This paper aims to explore the multiple layers of oppression women go through in the postcolonial, hetero-normative, orthodox, patriarchal society as portrayed in Toni Morrison’s 1987 novel Beloved and Latifa al-Zayyat’s novel The Open Door, which she wrote in the year 1960. It also attempts to understand and highlight how different Female Bildungsromans are when compared to the conventional Male Bildungsromans. The intensity of the struggle which the protagonists of these novels are facing, makes one dub these novels as “The Ugly Bildungsromans”. Two characters from different spaces and different times, Layla from The Open Door and Sethe from Beloved, are discussed in this paper as one attempts to underscore the similarities, as well as the differences their struggles have, while also attempting to accentuate the reasons for the similarities and differences. Both of the characters are frustrated existences due to their social condition, and are required to make choices in order to reclaim their identities as human beings

Study of antimicrobial effect for some extracts of Anabasis aphylla on Salmonella

ABSTRACT In this study, determine the inhibitory effect of Aqueous, Alcoholic, Flavonoid, Glycoside extracts of plant Anabasis aphylla on the salmonella, the microbial strain was exposed to the following four different concentrations of extracts 1, 10, 25 and 100 mg/ml. there has been an increasing effect on microbial growth inhibition with increasing concentration of extracts. The largest zone of inhibition was obtained with Flavonoid extract (24mm). The results For the study showed that the Aqueous extract of Anabasis aphylla has the inhibitory effect on the growth of bacteria which used in the study by inhibition diameter 20 mm, also gave Alcoholic extract inhibitory effect on bacterial growth by inhibition in diameter 15 mm, and gave aglycoside extract inhibitory effect on bacterial growth by inhibition in diameter 14 mm, the antimicrobial activity of extracts was compared with standard antibiotics like amoxicillin and ketoconazole (100µg/disk)

Problem-Based Learning Strategy Effect on Nurses' Knowledge and Patients' Health Behaviour Outcomes Post Myringoplasty

Myringoplasty is a repair of tympanic membrane perforation to restore and improve hearing function. Health belief model (HBM) is the suggested tool to measure the effect of post-operative instructions using problem-based learning strategy on patients' to maintain hearing and health behaviour. A well prepared nursing staff provides long lasting instructions for patients. The study aimed to evaluate the effect of problem-based learning strategy on nurses' knowledge and patients' health behaviour outcomes post myringoplasty. Research design: A quasi-experimental research design was utilized to meet the aim of this study. Setting: The study was conducted in Aswan University Hospital at the Department of Ear Nose and Throat. Sample: all available nurses (30 nurses) who have been working in the study setting, and 60 adult patients admitted at the time of the data collection were included in the study setting. Three tools were used for data collection, tool (1): Assessment of nurses' knowledge sheet developed by the researcher, and tool (2): HBM sheet according to Ruba etal. (2016), tool (3):  assessment of patient complications sheet developed by the researcher. Results: in the present study, findings significant correlation of pre-operative nurses knowledge related to pre and post learning strategy P-value < 0.05. In addition there were a highly significant correlation of post-operative nurses knowledge related to pre and post learning strategy P-value< 0.001. As regard to health belief model there was significant correlation between pre learning strategy, post one month & after three months of post-operative instructions, in relation to HBM. Conclusion: Nurses' knowledge and skills differed with respect to the mean score. Introducing of problem-based learning strategy and hand out booklet were effective in improving the level of nurses’ knowledge regarding post-operative instructions of patients with myringoplasty. Notably it revealed that, satisfactory patients' outcomes post applying the strategy in relation to HBM. Recommendations: All nurses should be aware by instructions that given to patients' pre discharge and inform patients about them. Keywords: problem-based learning strategy, complications, myringoplasty, Health Belief Model

The Grammatical Effort of Taqi Eldeen Al-Neely in his Book "AL- Tuhfa AL- Shafia"

يدرس هذا البحث الجهد النحوي لتقي الدين النيلي الحلي من علماء القرن السابع الهجري في كتابه "التحفة الشافية "وهو كتاب تعليمي يشرح فيه النيلي متن كافية ابن الحاجب , ومتن الكافية هو متن صعب على الدارسين استعصت مادته على الكثير منهم مما دفع النيلي الى حل اشكالاته وتيسير مباحثه النحوية وكان لهذا الشرح صدى واسع عند أكابر النحويين اللاحقين لزمن النيلي أذ نقلوا الكثير من أقواله وانتفعوا من ردوده واعتراضاته واختياراته وقد قسمت المادة المدروسة على ثلاثة مباحث أولها مسائل الأسماء وثانيها مسائل الأفعال وثالثها مسائل الحروف وكان من أبرز نتائج البحث إثبات أن كان له مشاركة فاعلة في تقويم المسائل النحوية وتحقيق أحكام مستقلة له في كتابه "التحفة الشافية" نالت عناية الدارسين بعده فضلاً عن أن البحث قد ناقش آراء النيلي فلم تسلم من القبول والرد بحسب مقتضيات البحث العلمي الرصين.This research studies the grammatical effort of at Taqi AL Deen AL. Neely, who is the seventh century , or Hijra in his book AL. TuhfaAL.Shafia '' which is an educational book the explains the content of '' kafiatIbnHajib " which is difficult to study by many students. this made AL. Neely solve its problems and made them easy     This explanation has a big reputation to the big grammatists that came later who took many of his  speeches and made benefits from his replays , objections and choices.     The studied material was divided into three sections , the first was the nouns matters , the second was the verbs matters and the third was the letters matters. the most noticeable results for this research is that AL.Neely had a big contribution to the correction of the grammatical matters and making independent opinions in his book " AL.Tuhfa AL. Shafia " which get the respect and attention of the students later on. in addition that the research had discussed  AL Neely opinions so it had an acceptance and refusals as a staid scientific research.  &nbsp

Pixel steganography method for grayscale image steganography on colour images

The process of hiding secret data within a host signal is known as steganography; its design parameters are imperceptibility, concealment capacity, and recovered data quality. A case of images, one of the existing methods based on modification of the host image pixels is called Block Pixel Hiding Method (BPHM), which has good imperceptibility and high-capacity concealment but does not guarantee the quality of the secret image recovered. This article proposes a method that improves results BPHM based on band selection and search algorithm global called Improved Pixel Hiding Method (IPHM). According to the simulations carried out, the results obtained with IPHM are better than those obtained with BPHM. They are similar to one of the more popular methods in imaging steganography known as Quantization Index Modulation (QIM). Steganography is the method of hiding hidden data within a host signal, with imperceptibility, concealment capacity, and retrieved data quality as design criteria. In the case of images, Block Pixel Hiding Method (BPHM) is one of the available methods based on modifying the host picture pixels, which has good imperceptibility and high-capacity concealment but does not guarantee the quality of the hidden picture recovered. Improved Pixel Hiding Method is a method proposed in this article that improves BPHM outcomes by using band selection and a global search algorithm (IPHM). The results obtained using IPHM are better than those achieved with BPHM, according to simulations. They're related to Quantization Index Modulation, which is one of the most widely used picture steganography techniques (QIM)

Comparative Evaluation of Marginal Adaptation of Two Sealers with Two Different Obturation Techniques Using SEM (AN IN VITRO STUDY)

Objective To evaluate and compare the marginal adaptation of epoxy resin-based sealer (AH Plus) versus Bioceramic-based sealer (Total fill BC Sealer) to root canals that were filled by single cone technique & Cold Lateral compaction technique and utilizing scanning electron microscope (SEM). Methods Sixty recently extracted single-rooted mandibular premolars were disinfected. Access cavity preparation was performed followed by cleaning and shaping, using 2.6% NaOCl as final irrigation protocol. Samples were then equally divided into 4 different groups as follows; Group A: AH Plus with CLC technique, Group B: AH Plus with SC technique, Group C: Totalfill BC with CLC technique, and Group D: Total fill Bioceramic sealer with single cone technique. After cleaning and shaping, each sample was obturated with Gutta percha and the sealer according to group of allocation. Afterwards, Transverse sectioning of each root was done at three, six, nine millimeters from the root apex corresponding to the three thirds of the root (apical, middle and coronal thirds). The specimens have been examined under scanning electron microscope (SEM). A commercially accessible software programme (SPSS Chicago, IL, USA) was used for the statistical analysis. The mean and standard deviation were used to describe numerical data. According to data normality, the Kruskall Wallis or ANOVA test was used to compare the data. A P 0.05 significance threshold was used. Every test had two tails. Results BC sealer presented better marginal adaptation than AH Plus sealer. However, On marginal adaption, there was no discernible difference between the two examined obturation techniques. Conclusion BC sealer is a reliable and promising material that improves marginal adaptation. Keywords: AH Plus sealer, BC sealer, Cold lateral condensation, Marginal adaptation, Single cone obturation

Quality Assessment of Nuclear physics journals by comparing bibliometrics indicators

Purpose: The present study aimed to assess and review the quality of journals from the field of nuclear physics based on some selected high-quality bibliometrics indicators, namely Journal Impact Factor (JIF), Eigenfactor Score (ES), SCImago Journal Rank (SJR) and H5-index. Methodology: Nineteen (19) nuclear physics journals from the Web of science core collection and Scopus database have been retrieved and tabulated under each mentioned indicator as per the ranks and values for the analysis. The analysis has done by using IBM SPSS (21.0). Findings: Bivariate correlation coefficient have been considered, a high Pearson’s (r) observed between JIF and SJR (r = 0.957) while the lowest observed between JIF and ES (r = 0.033). Spearman’s rank correlation coefficient (ρ) found very high between JIF and SJR (ρ =0.963) and very low between JIF and ES (ρ = 0.281). Thus, JIF and SJR show a strong correlation with each other. Limitation: The journals considered for assessment only from the field of nuclear physics indexed in Web of science core collection, hence only 19 journals have found for the evaluation. Originality/Value: This study will be helpful for the researchers and academicians from nuclear physics, looking for highly cited quality journals to publish their scientific research paper, as well as for the librarians/information scientists looking for high-quality collection development

Robust methods for inferring sparse network structures

This is the post-print version of the final paper published in Computational Statistics & Data Analysis. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2013 Elsevier B.V.Networks appear in many fields, from finance to medicine, engineering, biology and social science. They often comprise of a very large number of entities, the nodes, and the interest lies in inferring the interactions between these entities, the edges, from relatively limited data. If the underlying network of interactions is sparse, two main statistical approaches are used to retrieve such a structure: covariance modeling approaches with a penalty constraint that encourages sparsity of the network, and nodewise regression approaches with sparse regression methods applied at each node. In the presence of outliers or departures from normality, robust approaches have been developed which relax the assumption of normality. Robust covariance modeling approaches are reviewed and compared with novel nodewise approaches where robust methods are used at each node. For low-dimensional problems, classical deviance tests are also included and compared with penalized likelihood approaches. Overall, copula approaches are found to perform best: they are comparable to the other methods under an assumption of normality or mild departures from this, but they are superior to the other methods when the assumption of normality is strongly violated