1,594 research outputs found
3D seismic geomorphology of fluvial systems
Fluvial sandstones constitute one of the major clastic petroleum reservoir types in
many sedimentary basins around the world. This is especially true in the Tertiary
basins of Southeast Asia, which display a wide range of fluvial channel reservoir
types. This study is based on the analysis of high-resolution, shallow (seabed to ca.
500 m depth) 3D seismic data which provide exceptional imaging of the geometry,
dimension and temporal and spatial distribution of fluvial channels. The Malay Basin
comprises a thick (>8 km), rift to post-rift Oligo-Miocene to Pliocene basin-fill. The
youngest (Miocene to Pliocene), post-rift succession is dominated by a thick (1-5 km),
cyclic succession of coastal plain and coastal deposits, which accumulated in a humidtropical
climatic setting.
This study focuses on the Pleistocene to Recent (ca. 500 m thick) succession, which
comprises a range of seismic facies, mainly reflecting changes in fluvial channel style
and gross stratigraphic architecture. The succession has been divided into four seismic
units (Unit 1-4), bounded by basin-wide stratal surfaces. Units 3 and 4 have been
further divided into two sub-units. Two types of boundaries have been identified: 1) a
boundary that is defined by a regionally-extensive erosion surface at the base of a
prominent incised valley (e.g. Horizons C.1 and D.1); 2) a sequence boundary that is
defined by more weakly-incised, straight and low-sinuosity channels which is
interpreted as lowstand alluvial bypass channel systems (e.g. Horizons A, B, C, and
D). Each unit displays a predictable vertical change of the channel pattern and scale,
with wide low-sinuosity channels at the base passing gradationally upwards into
narrow high-sinuosity channels at the top. The wide variation in channel style and size is interpreted to be controlled mainly by the sea-level fluctuations on the widely flat
and tectonically-quiescent Sundaland Platform
Can Formative Assessment and Corrective Feedback Improve L2 Learners’ Performance on English “Comparative Forms”? The Case of Low-Proficiency Level EFL Learners
This study aims to examine the impact of formative assessment with corrective feedback as one of the effective tools that improve the performance of students who study English as a second language (L2 learners). More specifically, it contributes to research on the complex relationship between the attitudes and practices of English language teachers and students regarding the way they understand and practice the basics of formative assessment and corrective feedback when checking students’ achievement. In order to achieve this goal, the study investigated this matter in light of the following guiding questions: What are the effects of corrective and formative feedback in improving students who are learning English as a second language level L2 learners? How might teachers provide effective assistance to their students during this stage?To address these questions, A total of 58 subjects were divided into a control group (n=29) and an experimental group (n=29). All the subjects were second-year cadets at a military academy. Both groups were given a pre-test prior to the teaching of English “comparative forms”. The purpose of the pre-test was to make sure that the two groups were homogenous. The pre-test was then followed by the teaching of English “comparative forms” in both groups. The experimental group was given a formative assessment where each subject also received one-on-one corrective feedback. Finally, a post-test (summative assessment) was given to both groups.After collecting and analyzing the data, it was found that providing a formative assessment and corrective feedback has a positive impact on improving students’ level of accurate understanding accurately and student writing as well as correct reading
Saudi Student and Teacher Perceptions of Poor High School Results and Overall Proficiency in English
“English is the only foreign language taught in Saudi schools as part of the mandatory curriculum and therefore enjoys a relatively high status” (Carfax Educational Projects, 2016, p. 10). The teaching of English as a Foreign Language (EFL/L2) within the basic curriculum of Saudi Arabia commences in the fourth grade. However, in spite of the best efforts of the Saudi Ministry of Education (MoE) to develop English learning in schools, the language proficiency of Saudi high school leavers remains insufficient to carry out even basic interactions, let alone undertake university study through the medium of English (Al-Johani, 2009; Al-Seghayer, 2014; Alhawsawi, 2013; Alrabai, 2016; Khan, 2011; Rajab, 2013). In fact, the recent Test of English as a Foreign Language (TOEFL iBT, 2017) demonstrated an overall average score of 64 of 120 for Saudis who took the TOEFL iBT between January and December 2016. This paper therefore seeks to examine the factors responsible for the low EFL performance of Saudi students on completion of their high school studies. In order to do so, the researcher randomly selected 60 school leavers and 30 teachers who responded to an interview designed to elicit the underlying causes of such poor English proficiency. The results revealed that the reasons fall into a number of discrete categories related to the student, the teacher, the learning environment, and the curriculum
The Use of Technology in English Language Teaching
The application of modern technology represents a significant advance in contemporary English language teaching methods. Indeed, Mohammad Reza Ahmadi (2018) maintains that electronic teaching programmes have become the predominant preference of instructors since they arguably boost positive student engagement with teachers and incentivize overall English language learning. Most contemporary English language teachers now actively incorporate a range of technological aids designed to facilitate optimum teaching delivery. The current research therefore addresses various elements of the technology used in English teaching by devising innovative curricula which harnesses recent scientific and technical developments, equip instructors with the technological skills to ensure effective and quality subject delivery, provide technical media such as audio-visual and modern technical programmes, and create student-teacher platforms which maximize positive language learning outcomes. For the purposes of this study, the relevant literature has been reviewed, technology defined linguistically and conventionally, and correlation with modern teaching skills fully evaluated. In light of this, the researcher outlines the fundamental research problem, elucidates the significance of the research objectives and hypotheses, and presents the findings. The paper concludes by offering a number of recommendations which may further contribute to the improvement of teaching methods by advancing the widespread application of modern technology
A COMPUTATIONAL MODEL RELATING TISSUE OXYGEN CONSUMPTION TO OXYGEN DELIVERY IN A KROGH CYLINDER MODEL OF SKELETAL MUSCLE
Oxygen transport from a capillary to skeletal muscle tissue is a complex process that involves convective and diffusive mechanisms to deliver adequate oxygen to meet tissue metabolic activities. Typically, oxygen uptake in tissue is set by oxygen demand, which is set by metabolic activity. The relationship between the oxygen consumption (VO2) of an isolated perfused tissue and the rate of delivery of oxygen (QO2) to the tissue has been a subject of interest to many investigators over the past century. Experiments have shown that there is a critical value of QO2 below which tissue VO2 begins to decline. The Michaelis-Menten kinetics model for oxygen-dependent oxygen consumption is investigated as a modeling assumption in a computational study of oxygen transport from capillaries to skeletal muscle tissue using the Krogh cylinder model. The work presented in this thesis extends Schumacker and Samsel’s computational model to include the more accurate Michaelis-Menten kinetic description of the oxygen tension (PO2) dependence of VO2, using the parameter km, the PO2 for half-maximal VO2. This study aims to predict the relationship between oxygen consumption and oxygen delivery by considering the oxygen transport processes at the microvascular level. The dependence of oxygen consumption on oxygen delivery, critical oxygen extraction, critical oxygen delivery, and tissue oxygen tension profiles were examined as a function of km. The critical oxygen delivery was found to depend on km, increasing nonlinearly as km increases. The fractional oxygen extraction at the critical QO2 varied inversely with km. The venous oxygen partial pressure (PvO2) also varied with km. Finally, the predicted radial profile of tissue oxygen tension at the critical QO2 depended on km. At lower critical oxygen delivery and at lower km, the critical radial distance at which tissue oxygen partial pressure was found to be km occurred closer to the end of the capillary. The present results suggest that the value of km influences the relationship between tissue oxygen consumption and oxygen supply as the oxygen delivery is reduced to the critical point. Ultimately, km becomes the fundamental parameter that specifies how oxygen consumption depends on oxygen tension instead of the critical mitochondrial oxygen tension
Utilising artificial neural networks (ANNs) towards accurate estimation of life-cycle costs for construction projects
This study aimed to establish a new model of Life Cycle Cost (LCC) for construction projects using Artificial Neural Networks (ANNs). Survey research and Costs Significant Items (CSIs) methods were conducted to identify the most important cost and non-cost factors affecting the estimation of LCC. These important factors are considered as input factors of the model. The results indicated that neural network models were able to estimate the cost with an average accuracy between 91%-95%
Fair and Diverse Group Formation Based on Multidimensional Features
The goal of group formation is to build a team to accomplish a specific task. Algorithms are being developed to improve the team\u27s effectiveness so formed and the efficiency of the group selection process. However, there is concern that team formation algorithms could be biased against minorities due to the algorithms themselves or the data on which they are trained. Hence, it is essential to build fair team formation systems that incorporate demographic information into the process of building the group. Although there has been extensive work on modeling individuals’ expertise for expert recommendation and/or team formation, there has been relatively little prior work on modeling demographics and incorporating demographics into the group formation process.
We propose a novel method to represent experts’ demographic profiles based on multidimensional demographic features. Moreover, we introduce three diversity ranking algorithms that form a group by considering demographic features along with the minimum required skills. Unlike many ranking algorithms that consider one Boolean demographic feature (e.g., gender or race), our diversity ranking algorithms consider multiple demographic features simultaneously. Finally, we introduce a fair team formation algorithm that balances each candidate\u27s demographic information and expertise. We evaluate our proposed algorithms using real datasets based on members of a computer science program committee. The result shows that our algorithms form a program committee that is more diverse with an acceptable loss in utility
Zone-Based Privacy-Preserving Billing for Local Energy Market Based on Multiparty Computation
This paper proposes a zone-based privacy-preserving billing protocol for
local energy markets that takes into account energy volume deviations of market
participants from their bids. Our protocol incorporates participants' locations
on the grid for splitting the deviations cost. The proposed billing model
employs multiparty computation so that the accurate calculation of individual
bills is performed in a decentralised and privacy-preserving manner. We also
present a security analysis as well as performance evaluations for different
security settings. The results show superiority of the honest-majority model to
the dishonest majority in terms of computational efficiency. They also show
that the billing can be executed for 5000 users in less than nine seconds in
the online phase for all security settings, demonstrating its feasibility to be
deployed in real local energy markets
Oral health status and treatment needs of children with sickle cell disease in Abha and Khamis Mushait cities of southern Saudi Arabia
Background: This study aimed to assess the oral health status and dental treatment needs of children with Sickle Cell disease (SCD) in Abha and Khamis Mushait cities of southern Saudi Arabia.Methods: A total of 82 children were included in the study, 41 children with SCD and 41 control group. A total of 82 children having age group of 2 to 13 years from Abha and Khamis Mushait cities of southern Saudi Arabia were examined. The clinical examinations were performed by experienced clinicians in those children who fulfilled the required inclusion criteria. Intraoral examination was done using Decayed-Missing-Filled Teeth Index (DMFT Index) and other dental conditions were examined. Statistical analysis was done with Chi square test and level of significance was set at p<0.05.Results: Prevalence of dental caries was shown between the 2 groups of children i.e., SCD and control. When SCD was compared with control group, the Mean ±Standard deviation for decayed missing filled tooth was found to be DMFT= 6.95±4.79, 8.02±4.33 respectively. Statistically no significant difference was found (P=0.290). 17.1% of children with SCD group has gingivitis compared to control group which is 7.3%. Statistically no significant difference was found (P=0.177). Dental trauma, deleterious oral habits and tooth brushing amount SCD children were shown no statistically significant compared to control group.Conclusions: In the present study no significant difference was evident in dental diseases and treatment needs among SCD and Control group
- …