Application of Pattern Search Method to Power System Economic Load Dispatch

Direct Search (DS) methods are evolutionary algorithms used to solve constrained optimization problems. DS methods do not require information about the gradient of the objective function while searching for an optimum solution. One of such methods is Pattern Search (PS) algorithm. This study examines the usefulness of a constrained pattern search algorithm to solve well-known power system Economic Load Dispatch problem (ELD) with a valve-point effect. For illustrative purposes, the proposed PS technique has been applied to various test systems to validate its effectiveness. Furthermore, convergence characteristics and robustness of the proposed method have been assessed and investigated through comparison with results reported in literature. The outcome is very encouraging and suggests that pattern search (PS) may be very useful in solving power system economic load dispatch problems

Guests\u27 Waiting Experience at Hotels: Evidence From Saudi Arabia

The main purpose of this study was to explore guests’ waiting experience at hotels in Saudi Arabia, as well as the role of delay on overall experience. Investigating the effects of guests’ waiting experience on service quality and subsequent satisfaction with overall experience is the main aim of this study. In particular, this study had three objectives. First, to explore guests’ perceptions about their wait experiences in the hospitality industry. Second, to understand the factors that cause unacceptable waiting times. Third, to provide some important insights into the management of the long waiting times in the hotel industry. Employing a qualitative method, the study was conducted by interviewing 15 guests in person at a five-star hotel in Riyadh. The study also included interviews with four hotel staff at the same hotel. Based on a semi-structured approach, the interview questions were drawn from three main sources: the objectives of the study, the relevant literature, and empirical studies focusing on customers’ wait experiences in the hospitality industry. The study found that the majority of guests were more satisfied by the services provided and hotel location. However, the observed unsatisfactory service was the crowding in the hotel parking located in the basement of the hotel. Many guests faced a delay with valet car service. Another important finding was the variety of food offered at the hotel restaurant. Food variety was limited at breakfast time, and there was a long queue at the buffet table. Although there were some delays at the hotel, guests were satisfied with their overall experience. The most interesting finding was that the hotel doesn’t engage the guest in activities during the waiting period unless the service provider fails to provide the service on time

The epistemological beliefs of undergraduates towards Information Science

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonIn the past four decades considerable efforts have been taken by higher education to understand learner’s differences and learning. Learners have different levels of learning ability associated with their different learning motivations, attitudes and thoughts which are built through years of studying at university. The more the researchers understand the learner's differences the better results they will achieve in covering all levels of learning abilities providing the effective learning for learners. The focus of this study is about studying learning thoughts of academic learners which are scientifically called as the epistemological beliefs. Studying the epistemological beliefs from different angles is important to explore its vital role in learning development. The main aim of this study is to investigate the general and specific epistemological beliefs of undergraduates who study information literacy modules as part of information science. The study focuses on the influence of the independent variables (gender, major and academic level) and the interactions between the independent variables and information literacy on undergraduates’ epistemological beliefs. Two questionnaires are used to measure the general and specific epistemological beliefs of the undergraduates; the Schommer Epistemological-Beliefs Questionnaire (SEQ) and the Discipline-Focused Epistemological Belief Questionnaire (DFEBQ). The participants in the study are undergraduates from the College of Education at Kuwait University. SPSS is used to test the internal consistency of the data against the questionnaires. Analysis of variance (ANOVA) is used in order to analyse the data. The study confirms that undergraduates hold both general and specific-domain beliefs while they hold more general beliefs in their first year in the college they develop toward more specific domain beliefs in the fourth year. A final result shows that the undergraduates specific domain beliefs – rather than their general beliefs – are more affected by the variable of previous knowledge of information literacy, as well as a clear impact of the interaction between the independent variables but is not so clear on the general beliefs

A hybrid GA–PS–SQP method to solve power system valve-point economic dispatch problems

This study presents a new approach based on a hybrid algorithm consisting of Genetic Algorithm (GA), Pattern Search (PS) and Sequential Quadratic Programming (SQP) techniques to solve the well-known power system Economic dispatch problem (ED). GA is the main optimizer of the algorithm, whereas PS and SQP are used to fine tune the results of GA to increase confidence in the solution. For illustrative purposes, the algorithm has been applied to various test systems to assess its effectiveness. Furthermore, convergence characteristics and robustness of the proposed method have been explored through comparison with results reported in literature. The outcome is very encouraging and suggests that the hybrid GA–PS–SQP algorithm is very efficient in solving power system economic dispatch problem

A new scheme for prioritizing handoffs in cellular networks

The process that allows a call in progress to continue as the mobile terminal moves between cells is called a handoff . In cellular networks, call admission algorithms play an important role in improving the performance of the network. In this thesis, we present a new call admission algorithm that improves the quality of service in cellular networks by prioritizing handoff call requests over new call requests. This prioritization is based on defining a controlled dropping ratio that attempts to prevent dropping a handoff call until a pre-specified target number of new calls are blocked. The purpose of blocking new calls is to adaptively reserve bandwidth for handoff calls. The aim of this algorithm is to improve the quality of service of cellular networks by minimizing the grade of service, the non-completed call probability, and the channel non-utilization. The effectiveness of the new call admission algorithm in reducing the handoff dropping probability and the new call blocking probability was studied. (Abstract shortened by UMI.

Usability Guidelines for Arab E-Government Websites

The website developer and designer should follow usability guidelines to provide a user-friendly interface. Many guidelines and heuristics have been developed by previous studies to help both the developer and designer in this task, but E-government websites are special cases that require specialized guidelines. This paper introduces a set of eighteen guidelines for evaluating the usability of e-government websites in general and Arabic e-government websites specifically, along with a check list of how to apply them. The validity and effectiveness of these guidelines were evaluated against a variety of user characteristics. The results indicated that the proposed set of guidelines can be used to identify qualitative similarities and differences with user testing and that the new set is best suited for evaluating general and e-governmental usability

User interface requirements engineering : a scenario-based framework

Effective user interface is an important component to the success of an interactive system as any of the components that manage the underlying functionality of the system. The development of an effective user interfaces highly depends on the quality of the requirements where the end-user should be actively involved. Therefore, there is a need to accurately capture, interpret, and represent the voice of the end-user when specifying the user interface requirements. The objective of the thesis is to advance the state of the art in bridging the gap between specifying the User Interface Requirements for interactive systems on the one hand and the design and development of it on the other hand. Towards this objective, a software framework called SUCRE (acronym for Scenario and Use-Case based Requirements Engineering) was developed as a part of this thesis work. Use Case Maps (UCMs) that were introduced in the literature were examined and have been enriched with new visual notation for modeling and specifying the user interface requirements. This enriched UCM for User Interface (UCM-UI) model formed a basis for SUCRE. Thus, scenarios and use cases are used as a means to represent the user interface requirements and communicate with end-users. In addition, the thesis explores two other objectives, namely validation of user interface requirements and usability prediction of the intended user interface. SUCRE was used to build operators that validate the consistency, completeness, and precision of the UCM-UI model using heuristics for constructing a formal analysis of the requirements. SUCRE was also used to define a metrics suite to predict usability from scenarios and use cases. This metrics suite includes simple structural measures as well as content-sensitive and task-sensitive metrics. Considering the difficulties in the specification and design of user interfaces, the thesis aimed also to identify the need for a mix of both informal and formal representation in specifying user interface requirements. Therefore, SUCRE was successfully used to bridge the gap between the semi-formal requirement UCM-UI and detailed formal requirements such as UML, LOTOS specifications, and XML

Exploring Time-Sensitive Variational Bayesian Inference LDA for Social Media Data

There is considerable interest among both researchers and the mass public in understanding the topics of discussion on social media as they occur over time. Scholars have thoroughly analysed sampling-based topic modelling approaches for various text corpora including social media; however, another LDA topic modelling implementation—Variational Bayesian (VB)—has not been well studied, despite its known efficiency and its adaptability to the volume and dynamics of social media data. In this paper, we examine the performance of the VB-based topic modelling approach for producing coherent topics, and further, we extend the VB approach by proposing a novel time-sensitive Variational Bayesian implementation, denoted as TVB. Our newly proposed TVB approach incorporates time so as to increase the quality of the generated topics. Using a Twitter dataset covering 8 events, our empirical results show that the coherence of the topics in our TVB model is improved by the integration of time. In particular, through a user study, we find that our TVB approach generates less mixed topics than state-of-the-art topic modelling approaches. Moreover, our proposed TVB approach can more accurately estimate topical trends, making it particularly suitable to assist end-users in tracking emerging topics on social media

Loneliness and problematic internet use during COVID-19 lock-down.

(1) Background: During the COVID-19 pandemic, strict lock-down and quarantine were widely imposed by most governments to minimize the spread of the virus. Previous studies have investigated the consequences of the quarantine and social isolation on mental health and the present study examines loneliness and problematic internet use. (2) Methods: The current research used a cross-sectional survey during a lock-down phase of the COVID-19 pandemic. A sample of 593 participants from the Middle East region (Kuwait, Saudi Arabia) were tested using the short form of the Revised UCLA Loneliness Scale and the Internet Addiction Test. (3) Results: Results from regression analyses showed an association between loneliness and Problematic Internet Use (PIU), and an association between loneliness and the number of hours spent online. Younger participants reported greater loneliness. The quality of the relationship with the person(s) with whom they were spending their lock-down was also correlated with loneliness. Those who reported greater loneliness also obtained frequent news about the pandemic from social media. Problematic internet use was associated with loneliness and the predictors of loneliness. ANOVA analyses showed a dose-response between the predictors and PIU. (4) Conclusions: This study highlights the influence of the social characteristics of the local culture during the COVID-19 lock-down on feelings of loneliness and on PIU