Service recommendation and selection in centralized and decentralized environments.

With the increasing use of web services in everyday tasks we are entering an era of Internet of Services (IoS). Service discovery and selection in both centralized and decentralized environments have become a critical issue in the area of web services, in particular when services having similar functionality but different Quality of Service (QoS). As a result, selecting a high quality service that best suits consumer requirements from a large list of functionally equivalent services is a challenging task. In response to increasing numbers of services in the discovery and selection process, there is a corresponding increase of service consumers and a consequent diversity in Quality of Service (QoS) available. Increases in both sides leads to a diversity in the demand and supply of services, which would result in the partial match of the requirements and offers. Furthermore, it is challenging for customers to select suitable services from a large number of services that satisfy consumer functional requirements. Therefore, web service recommendation becomes an attractive solution to provide recommended services to consumers which can satisfy their requirements.In this thesis, first a service ranking and selection algorithm is proposed by considering multiple QoS requirements and allowing partially matched services to be counted as a candidate for the selection process. With the initial list of available services the approach considers those services with a partial match of consumer requirements and ranks them based on the QoS parameters, this allows the consumer to select suitable service. In addition, providing weight value for QoS parameters might not be an easy and understandable task for consumers, as a result an automatic weight calculation method has been included for consumer requirements by utilizing distance correlation between QoS parameters. The second aspect of the work in the thesis is the process of QoS based web service recommendation. With an increasing number of web services having similar functionality, it is challenging for service consumers to find out suitable web services that meet their requirements. We propose a personalised service recommendation method using the LDA topic model, which extracts latent interests of consumers and latent topics of services in the form of probability distribution. In addition, the proposed method is able to improve the accuracy of prediction of QoS properties by considering the correlation between neighbouring services and return a list of recommended services that best satisfy consumer requirements. The third part of the thesis concerns providing service discovery and selection in a decentralized environment. Service discovery approaches are often supported by centralized repositories that could suffer from single point failure, performance bottleneck, and scalability issues in large scale systems. To address these issues, we propose a context-aware service discovery and selection approach in a decentralized peer-to-peer environment. In the approach homophily similarity was used for bootstrapping and distribution of nodes. The discovery process is based on the similarity of nodes and previous interaction and behaviour of the nodes, which will help the discovery process in a dynamic environment. Our approach is not only considering service discovery, but also the selection of suitable web service by taking into account the QoS properties of the web services. The major contribution of the thesis is providing a comprehensive QoS based service recommendation and selection in centralized and decentralized environments. With the proposed approach consumers will be able to select suitable service based on their requirements. Experimental results on real world service datasets showed that proposed approaches achieved better performance and efficiency in recommendation and selection process.N/

Imperialism, Colonialism and Racism in Joseph Conrad's Heart of Darkness: A Postcolonial Approach

It is not easy to explore the inner side and the hidden nature of human beings. It is also what has strengthened the relationship between human beings and the issue of imperialism and colonialism and the final stage of colonialism which leads to racism. This paper deals with colonialism, imperialism, and racism in Joseph Conrad's novella, Heart of Darkness. The three stages colonizers implement during colonizing African countries.  Modern age and modern literature are shed light on in general and more particularly, modern novel is focused on as it is necessary for the analysis of the novel. Then the terms of colonialism, imperialism, and racism are explored in Heart of Darkness as these are interrelated words having close links to colonization. A postcolonial approach is used to analyze the novella

Solution Techniques Based on Adomian and Modified Adomian Decomposition for Nonlinear Integro-Fractional Differential Equations of the Volterra-Hammerstein Type

هذا البحث يطبق بفعاليه طريقه التحليل الادوميانى وطريقه التحليل الادوميانى المعدله كتقنيات عددية لتعيين الحل شبه التحليلى او الحل شبه التقريبى للمعادلات التفاضليه التكامليه اللاخطيه للرتب الكسريه (IFDE) من نوع فولتيرا-هاميرشتين (V-H) والتى توصف فيها المشتقه الكسريه المتعدده العليا بنمط كابوتو. فى هذا النهج سنغير بشكل جذرى ال (IFDE) لنوع  (V-H)  الى بعض معادلات جبريه تكراريه وان الحل لهذه المعادلات هو بمثابه مجموع من المتتابعات اللاعدديه (Countless) لمركبات متقاربه نوعيا للحل المستند (المعتمد)  على الحدود الضوضائيه وذلك فى حاله عدم حصولنا على حل من النوع المغلق وان الحدود المقطوعه (المحذوفه) يستخدم للاغراض العدديه. واخيرا تم اعطاء امثله لتوضيح هذه الافكار والاعتباراتThis paper efficiently applies the Adomian Decomposition Method and Modified Adomian Decomposition Method as computational techniques to locate the semi-analytical solution or semi-approximate solution for the considered nonlinear Integro Differential Equations for the fractional-order (IFDE) of the Volterra-Hammerstein (V-H) type, in which the higher-multi fractional derivative is described in the Caputo sense.In this procedure, we radically change the IFDE’s of V-H type into some iterative algebraic equations and the solution of this equations is considered as the sum of the countless sequence of components typically converging to the solution based on the noise terms where a closed-form solution is not obtainable, a truncated number of terms is usually used for numerical purposes.Finally, examples are prepared to illustrate these considerations

An efficient algorithm for partially matched services in internet of services

Internet of Things (IoT) connects billions of devices in an Internet-like structure. Each device encapsulated as a real-world service which provides functionality and exchanges information with other devices. This large-scale information exchange results in new interactions between things and people. Unlike traditional web services, internet of services is highly dynamic and continuously changing due to constant degrade, vanish and possibly reappear of the devices, this opens a new challenge in the process of resource discovery and selection. In response to increasing numbers of services in the discovery and selection process, there is a corresponding increase in number of service consumers and consequent diversity of quality of service (QoS) available. Increase in both sides’ leads to the diversity in the demand and supply of services, which would result in the partial match of the requirements and offers. This paper proposed an IoT service ranking and selection algorithm by considering multiple QoS requirements and allowing partially matched services to be counted as a candidate for the selection process. One of the applications of IoT sensory data that attracts many researchers is transportation especially emergency and accident services which is used as a case study in this paper. Experimental results from real-world services showed that the proposed method achieved significant improvement in the accuracy and performance in the selection process

The Impact of Social Media on the Interaction Between Students and Teachers at the University of Halabja

The aim of this article is to investigate the role of web 2.0 tools and social media applications in the relationship between undergraduate students and university lecturers. The researchers used the quantitative approach to design the methodology of the research. The sample of the study was 85 students from the departments of (Social Sciences, Arabic Language, and English Language) in the second year, third year, and fourth year at the college of basic education at the University of Halabja for the academic year 2020-2021. The questionnaire was used to collect the data from the participants. The result of the study demonstrated that there was a significant influence on the relationship between the students and the lecturers in using social media applications. Students showed that they use social media every day and it has a positive impact on their interaction with the lecturers

Cross-cultural comparison of mental illness stigma and help-seeking attitudes: a multinational population-based study from 16 Arab countries and 10,036 individuals

BackgroundThere is evidence that culture deeply affects beliefs about mental illnesses\u27 causes, treatment, and help-seeking. We aimed to explore and compare knowledge, attitudes toward mental illness and help-seeking, causal attributions, and help-seeking recommendations for mental illnesses across various Arab countries and investigate factors related to attitudes toward help-seeking.MethodsWe carried out a multinational cross-sectional study using online self-administered surveys in the Arabic language from June to November 2021 across 16 Arab countries among participants from the general public.ResultsMore than one in four individuals exhibited stigmatizing attitudes towards mental illness (26.5%), had poor knowledge (31.7%), and hold negative attitudes toward help-seeking (28.0%). ANOVA tests revealed a significant difference between countries regarding attitudes (F = 194.8, p \u3c .001), knowledge (F = 88.7, p \u3c .001), and help-seeking attitudes (F = 32.4, p \u3c .001). Three multivariate regression analysis models were performed for overall sample, as well as Palestinian and Sudanese samples that displayed the lowest and highest ATSPPH-SF scores, respectively. In the overall sample, being female, older, having higher knowledge and more positive attitudes toward mental illness, and endorsing biomedical and psychosocial causations were associated with more favorable help-seeking attitudes; whereas having a family psychiatric history and endorsing religious/supernatural causations were associated with more negative help-seeking attitudes. The same results have been found in the Palestinian sample, while only stigma dimensions helped predict help-seeking attitudes in Sudanese participants.ConclusionInterventions aiming at improving help-seeking attitudes and behaviors and promoting early access to care need to be culturally tailored, and congruent with public beliefs about mental illnesses and their causations

Synthesis of Polymer Nanocomposites Based on [Methyl Cellulose](1−x):(CuS)x (0.02 M ≤ x ≤ 0.08 M) with Desired Optical Band Gaps

In this paper, the sample preparation of polymer nanocomposites based on methyl cellulose (MC) with small optical bandgaps has been discussed. Copper monosulfide (CuS) nanoparticles have been synthesized from the sodium sulphide (Na2S) and copper chloride (CuCl2) salts. Distinguishable localized surface resonance plasmon (LSRP) absorption peaks for CuS nanoparticles within the 680–1090 nm scanned wavelength range were observed for the samples. An absorption edge (Ed) was found to be widely shifted to a lower photon energy region. A linear relationship between the refractive index of the samples and the CuS fraction was utilized to describe the distribution of the particle. The optical bandgap of MC was reduced from 6.2 to 2.3 eV upon the incorporation of 0.08 M of CuS nanoparticles. The optical dielectric loss, as an alternative method, was used successfully to estimate the optical bandgap. Moreover, the electronic transition type was identified by using Tauc’s extrapolation method. The plots of the optical dielectric constant and energy bandgap as a function of the CuS concentration were utilized to examine the validity of the Penn model. For the nanocomposite samples, the Urbach energy was found to be increased, which can be evidence for a large possible number of bands-to-tail and tail-to-tail transitions. However, from the X-ray diffraction (XRD) analysis, it was also found that the synthesized CuS nanoparticles disrupted the crystallinity phase of the MC polymer. Finally, fourier transform infrared (FTIR) spectroscopy for the samples was also performed. Significant decreases of transmittance intensity as well as band shifting in the FTIR spectra were observed for the doped samples

Effect of High Salt Concentration (HSC) on Structural, Morphological, and Electrical Characteristics of Chitosan Based Solid Polymer Electrolytes

Chitosan (CS) films doped with sodium triflate (NaTf) were prepared by the solution cast technique. The structural and morphological behaviors of the samples were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The XRD patterns were deconvoluted to estimate the degree of crystallinity of the samples. The SEM micrograph showed the crystalline structure of the sample contained 50 wt % of NaTf salt. The disappearance of broad peaks of chitosan at 2θ ≈ 21° and 2θ ≈ 32° confirmed the occurrence of ion association at 50 wt % of NaTf salt. In impedance plots, a low frequency spike region and a high frequency semicircle, were distinguishable for low salt concentrations. The highest ambient temperature direct current (DC) electrical conductivity obtained for CS:NaTf was found to be 2.41 × 10−4 S/cm for the sample containing 40 wt % of NaTf salt. The role of lattice energy of salts on DC ionic conductivity was also discussed. The temperature dependence of DC conductivity was found to follow the well-known Arrhenius relationship. From the alternating current (AC) conductivity spectra, three distinct regions were recognized for the samples with NaTf salt concentration ranging from 10 wt % to 30 wt %. The plateau region of AC spectra was used to estimate the DC conductivity

Role of Ion Dissociation on DC Conductivity and Silver Nanoparticle Formation in PVA:AgNt Based Polymer Electrolytes: Deep Insights to Ion Transport Mechanism

In this study, the role of ion dissociation on formation of silver nanoparticle and DC conductivityin PVA:AgNO3 based solid polymer electrolyte has been discussed in detail. Samples of silver ion conducting solid polymer electrolyte were prepared by using solution cast technique. Absorption spectroscopy in the ultraviolet–visible (UV–Vis) spectral region was used to investigate the formation of silver nanoparticles. Broad and sharp peaks due to plasmonic silver nanoparticles subjected to ion dissociation have been observed. The influence of dielectric constant on the intensity of surface plasmonic resonance (SPR) peaks attributed to silver nanoparticles was discussed. From impedance plots, the diameter of high frequency semicircle was found to be decreased with increasing salt concentration. The DC conductivity in relation to the dielectric constant was also explained. From the AC conductivity spectra, the dc conductivity was estimated to be close to that calculated from the bulk resistance. The temperature dependence of the DC conductivity was studied and found to follow Arrhenius equation within two distinguished regions. The AC conductivity at different temperatures has been studied to comprehend the ion conduction mechanism. The AC conductivity against frequency was found to obey the universal power law of Jonscher. Three distinct regions were recognized from the spectra of AC conductivity. The frequency exponent (S) was calculated for the dispersive region of the measured AC conductivity spectra. Various models were discussed to explain the behavior of S value with temperature. The behavior of S value with temperature was then used to interpret the DC conductivity pattern against 1000/T. Finally, from the comparison of calculated activation energy (Ea) and maximum barrier height (Wm), deep insights into ion conduction mechanism could be grasped