Boundedness character of a max-type system of difference equations of second order

The boundedness character of positive solutions of the next max-type system of difference equations $$x_{n+1}=\max\left\{A,\frac{y_n^p}{x_{n-1}^q}\right\},\quad y_{n+1}=\max\left\{A,\frac{x_n^p}{y_{n-1}^q}\right\},\quad n\in\mathbb{N}_0,$$ with $\min\{A, p, q\}>0$, is characterized

On a higher-order system of difference equations

Here we study the following system of difference equations xn = f −1 cnf(xn−2k) ∏k an + bn i=1 g(y) n−(2i−1))f(xn−2i) yn = g −1 γng(yn−2k) ∏k αn + βn i=1 f(x) n−(2i−1))g(yn−2i) n ∈ N0, where f and g are increasing real functions such that f(0) = g(0) = 0, and coefficients an, bn, cn, αn, βn, γn, n ∈ N0, and initial values x−i, y−i, i ∈ {1, 2,..., 2k} are real numbers. We show that the system is solvable in closed form, and study asymptotic behavior of its solutions

Time-Dependent Physicochemical Changes of Carbonate Surfaces from SmartWater (Diluted Seawater) Flooding Processes for Improved Oil Recovery.

Over the past few decades, field- and laboratory-scale studies have shown enhancements in oil recovery when reservoirs, which contain high-salinity formation water (FW), are waterflooded with modified-salinity salt water (widely referred to as the low-salinity, dilution, or SmartWater effect for improved oil recovery). In this study, we investigated the time dependence of the physicochemical processes that occur during diluted seawater (i.e., SmartWater) waterflooding processes of specific relevance to carbonate oil reservoirs. We measured the changes to oil/water/rock wettability, surface roughness, and surface chemical composition during SmartWater flooding using 10-fold-diluted seawater under mimicked oil reservoir conditions with calcite and carbonate reservoir rocks. Distinct effects due to SmartWater flooding were observed and found to occur on two different timescales: (1) a rapid (<15 min) increase in the colloidal electrostatic double-layer repulsion between the rock and oil across the SmartWater, leading to a decreased oil/water/rock adhesion energy and thus increased water wetness and (2) slower (>12 h to complete) physicochemical changes of the calcite and carbonate reservoir rock surfaces, including surface roughening via the dissolution of rock and the reprecipitation of dissolved carbonate species after exchanging key ions (Ca2+, Mg2+, CO32-, and SO42- in carbonates) with those in the flooding SmartWater. Our experiments using crude oil from a carbonate reservoir reveal that these reservoir rock surfaces are covered with organic-ionic preadsorbed films (ad-layers), which the SmartWater removes (detaches) as flakes. Removal of the organic-ionic ad-layers by SmartWater flooding enhances oil release from the surfaces, which was found to be critical to increasing the water wetness and significantly improving oil removal from carbonates. Additionally, the increase in water wetness is further enhanced by roughening of the rock surfaces, which decreases the effective contact (interaction) area between the oil and rock interfaces. Furthermore, we found that the rate of these slower physicochemical changes to the carbonate rock surfaces increases with increasing temperature (at least up to an experimental temperature of 75 °C). Our results suggest that the effectiveness of improved oil recovery from SmartWater flooding depends strongly on the formation of the organic-ionic ad-layers. In oil reservoirs where the ad-layer is fully developed and robust, injecting SmartWater would lead to significant removal of the ad-layer and improved oil recovery

IMPROVING COLLABORATIVE FILTERING RECOMMENDER BY USING MULTI-CRITERIA RATING AND IMPLICIT SOCIAL NETWORKS TO RECOMMEND RESEARCH PAPERS

Research paper recommender systems (RSs) aim to alleviate the information overload of researchers by suggesting relevant and useful papers. The collaborative filtering in the area of recommending research papers can benefit by using richer user feedback data through multi-criteria rating, and by integrating richer social network data into the recommender algorithm. Existing approaches using collaborative filtering or hybrid approaches typically allow only one rating criterion (overall liking) for users to evaluate papers. We conducted a qualitative study using focus group to explore the most important criteria for rating research papers that can be used to control the paper recommendation by enabling users to set the weight for each criterion. We investigated also the effect of using different rating criteria on the user interface design and how the user can control the weight of the criteria. We followed that by a quantitative study using a questionnaire to validate our findings from the focus group and to find if the chosen criteria are domain independent. Combining social network information with collaborative filtering recommendation algorithms has successfully reduced some of the drawbacks of collaborative filtering and increased the accuracy of recommendations. All existing recommendation approaches that combine social network information with collaborative filtering in this domain have used explicit social relations that are initiated by users (e.g. “friendship”, “following”). The results have shown that the recommendations produced using explicit social relations cannot compete with traditional collaborative filtering and suffer from the low user coverage. We argue that the available data in social bookmarking Web sites can be exploited to connect similar users using implicit social connections based on their bookmarking behavior. We explore the implicit social relations between users in social bookmarking Web sites (such as CiteULike and Mendeley), and propose three different implicit social networks to recommend relevant papers to users: readership, co-readership and tag-based implicit social networks. First, for each network, we tested the interest similarities of users who are connected using the proposed implicit social networks and compare them with the interest similarities using two explicit social networks: co-authorship and friendship. We found that the readership implicit social network connects users with more similarities than users who are connected using co-authorship and friendship explicit social networks. Then, we compare the recommendation using three different recommendation approaches and implicit social network alone with the recommendation using implicit and explicit social network. We found that fusing recommendation from implicit and explicit social networks can increase the prediction accuracy, and user coverage. The trade-off between the prediction accuracy and diversity was also studied with different social distances between users. The results showed that the diversity of the recommended list increases with the increase of social distance. To summarize, the main contributions of this dissertation to the area of research paper recommendation are two-fold. It is the first to explore the use of multi-criteria rating for research papers. Secondly, it proposes and evaluates a novel approach to improve collaborative filtering in both prediction accuracy (performance) and user coverage and diversity (nonperformance measures) in social bookmarking systems for sharing research papers, by defining and exploiting several implicit social networks from usage data that is widely available

Metacognitive skills, perfectionism, and academic self-efficacy As predicators of achievement goal orientations among Sample of graduate students in Education College

This study aimed toinvestigate the possibility of predicting achievement goal orientations from metacognitive skills, perfectionism, and academic self-efficacy among graduate students. The study sample consisted of 182 graduate students from the College of Education at King Saud University. In this study, four types of scales were used, namely the 2x2 Achievement Goal Orientation Scale developed by Elliot andMcGregor (2001) the Metacognitive Skills Scale developed by Al-Watban (2006), the Adaptive and Maladaptive Scale developed byFrostetet. al (1993) and the Academic Self-Efficacy Scale developed by Wood and Locke (1987). The results of the study revealed that there were significant impacts of metacognitive skills, perfectionism, and academic self-efficacy on achievement goal orientations, and metacognitive skills, adaptive perfectionism, and academic self-efficacy were good predicators of mastery-approach goal orientation. In addition, there was a good possibility of predicting performance-avoidance goal orientation from both maladaptive perfectionism and academic self-efficacy. The results also showed that two types of perfectionism can be a good predicator of mastery-avoidance, and maladaptive one can predict performance-approach goal orientations

AN ANALYSIS OF THE IMPLICATIONS OF THE GROWING TABLOIDIZATION OF NEWS COVERAGE ON DEMOCRATIC POLITICS

This study is a literature review to explore the effect of the growing tabloidization of news coverage on democratic politics. The study focuses on some important considerations, among which are three basic values of modern democratic societies, namely, freedom, justice and order, which it is vital to retain. While these basic values in mass media communication are not compromised, it is difficult to deny that the media, tabloid or not, cause a crisis in public life. This crisis means that ‘core values’ such as independence, diversity and objectivity risk being lost because of changes in the media. Such changes are due to pressures from the market and society, but these pressures have not been shown to hinder democratic life

Exploring the implementation of total quality management in Saudi Arabia

The study explores the implementation of Total Quality Management in Saudi Arabia. Particularly, it investigates the factors affecting the implementation of TQM in the educational sector, ‘the Ministry of Education’, to fill a gap of knowledge in the previous literature. These factors are related to the organisational culture in the country. The thesis studies these factors and their relevance in affecting the implementation of TQM. This study aims to explore the nature of the relationship between Total Quality Management and Organisational culture. The first objective of this thesis is to explore the challenges that facing the education quality management in Saudi Arabia. The second objective is to identify the actions that being taken by the Ministry of Education to introduce TQM to the educational system. Finally, the third objective is to determine the factors affecting the implementation of Total Quality Management in the educational system in Saudi Arabia.Collecting data was via semi-structured interviews as the methodology is qualitative to provide an in-depth understanding of phenomena. Forty employees in the ministry were interviewed who had worked for the ministry for more than five years, so they understood the quality of educational system in the country. The main themes in the findings were identified by analysing them thematically using Miles and Huberman’s (1994) inductive approach.Regarding the first objective of this research, the findings illustrate the weakness of quality in the educational system in Saudi Arabia, which the interviewees ascribe to some issues such as weak pre-service training, lack of professionalism, misuse of performance evaluation, inconsistent standards of rewards and punishments. In addition, findings show that there are other issues with the quality of education related to school resources and the availability of materials, curriculum, and the centralisation in the system of the Ministry of Education. In regard to the second objective of this research, the findings show that the Ministry of Education has taken some important steps to raise the level of quality by establishing the Total Quality Management Department which has top-level support from the minister. Moreover, there are new programmes and trends made by the ministry such as new curricula, decentralisation, and teachers’ efforts to provide careers guidance. Regarding the third objective of this study, the findings illustrate that there are some obstacles facing the implementation of Total Quality Management in the educational system in Saudi Arabia. Training employees of the ministry and spreading the culture of TQM is facing issues such as insufficient training courses, unqualified trainers, access issues and lack of benefit from those training programmes. Cultural resistance from some parents and principals plays an important role hindering implementation of change. The findings of this study also show that the participation of the staff is not enough, whether they are teachers, principals or members of educational departments.This study contributes knowledge at both practical and academic levels. At practical level, it offers has pointed recommendations for the ministry’s top management to increase the awareness of TQM importance in regard to improving the quality of educational system and to reach the maximum benefits to the employees and students. On the academic level, as this study gives insights regarding TQM implementation and an understanding of the nature of the TQM application process and the challenges that face its implementation. It contributes to knowledge of TQM by providing empirical evidence that may assist practitioners in the Arab context to improve TQM

Causes of Private Tutoring in English: Perspectives of Saudi Secondary School Students and Their Parents

The current study examined and described the views of secondary school students and their parents on the causes of private tutoring in English. These views were obtained through two group interviews with the students and parents separately. Several causes were brought up during the two interviews. These causes included difficulty of the English language, weak teacher performance, the need to pass exams with high marks, lack of parents’ follow-up of student school performance, social pressure, variability in student comprehension levels at school, weak English foundation in previous school years, repeated student absence from school, large classes, as well as English teachers’ heavy teaching loads. The study started with a description of the EFL educational system in Saudi Arabia and concluded with recommendations for the improvement of the school learning environment

Perancangan Dan Implementasi Augmented Reality Sebagai Media Promosi Penjualan Perumahan

Untuk melakukan promosi sebuah Perumahan banyak cara yang dapat dilakukan, misalnya dengan menggunakan brosur yang mana informasinya disampaikan dalam media dua dimensi, maket yang mana informasinya sudah dapat disampaikan dalam media tiga dimensi tetapi harus memerlukan ruang yang tidak sedikit untuk mewujudkannya demi mendapatkan hasil yang maksimal. Yang menjadi masalah disini adalah bagaimana menjadikan suatu informasi tersebut menjadi interaktif dan lebih menarik bagi konsumen. Dengan menggunakan teknik promosi berbasis augmented reality yang dibuat dengan menggunakan ARTool Kit sebagai komponen yang utama dan dengan menggunakan 3DS Max sebagai software untuk menghasilkan gambar yang menarik. Proses perancangan dan pembuatan teknik promosiini akan menggunkan metode waterfall. Kelebihan dari model waterfall adalah struktur tahap pengembangan sistem jelas, dokumentasi dihasilkan disetiap tahap pengembangan, dan sebuah tahap dijalankan setelah tahap sebelumnya selesai dijalankan (tidak ada tumpang tindih pelaksanaan tahap). Hasil dari perancangan aplikasi ini adalah terealisasinya suatu aplikasi untuk kepentingan promosipenjualan Perumahan yang lebih menarik dan interaktif dengan konsumen berbasis augmented reality. Dengan adanya aplikasi ini diharapkan metode promosi dapat berkembang dengan lebih menarik dan tentunya dengan mengandalkan teknologitanpa membutuhkan ruang yang banyak untuk mencapai hasil yang maksimal