59 research outputs found
Reward-based Crowdfunding Technological Projects Determinants of Success: A Quantitative Study
Crowdfunding success in terms of the achievement of target capital in reward-based crowdfunding projects is impacted by many factors (e.g., past created projects, campaign duration, pledged capital). This paper studies the determinants of success rate (pledged capital/target capital) or (P/T) in successful technological crowdfunding projects. The quantitative study started by data collection of 328 successful Kickstarter technological crowdfunding campaigns which are later decreased to 289 due to model censorship. Tobit model was adopted as the censored linear regression model to determine the existence of relationships between the dependent variable (P/T) and the independent variables. Results suggest that success rate is associated with 7 independent variables: visuals, duration, internal social capital, comments and education are found to impact success rate positively while target capital and past created projects are found to impact success rate negatively. The study contributes to the literature in crowdfunding by paving the path to study success factors that might impact successful technological projects, and to investigate the significance of backers’ feedback and project creators’ education in maximizing their campaign’s outcome
Enablers and obstacles in teaching and learning of mathematics: A systematic review in LUMAT journal
This paper presents results of a systematic review of papers published at the LUMAT journal on the current issues positively and negatively affecting teaching and learning in mathematics, in concurrence with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The analysis also offers insight into the most studied topics in mathematics education research, including key demographic and methodological characteristics such as year of publication, participants, education level, research methodologies, and research focus. Data was gathered from the studies published in the LUMAT: International Journal on Math, Science and Technology Education, starting from its first volume in 2013. So far, 225 articles were published in this journal, with 133 studies written in English and 51 studies related to mathematics. Although earlier studies support the notion that mathematics education is mostly traditional, this review suggests current research has thorough and positive outcomes, such that mathematics educators are likely to implement non-traditional approaches, encouraging student engagement, peer collaboration, and mathematical discourse. Certainly, in such learning environments, students tend to feel more motivated and less anxious about learning mathematics. They may also be more active and responsible in their learning, collaborate with peers, and get into mathematical discussions. Yet, there are also a number of difficulties and obstacles highlighted both in teaching and learning of mathematics. The findings might inspire several instructional implications for mathematics educators, curriculum developers, and researchers. Recommendations are given to add into what the existing literature claims and offer greater empirical evidence to support the verdicts
STEM learning during the COVID-19 pandemic in Qatar: Secondary school students’ and teachers’ perspectives
This study examines how students and teachers perceive science, mathematics, engineering and technology (STEM) learning during the COVID-19 pandemic. Data was collected through student and teacher surveys, conducted in 22 public and 17 private secondary schools at Qatar. Participants included 1,505 students and 545 teachers in grades 11 and 12. Results showed students’ and teachers’ demographic factors, including gender, school type, grade level, and majors, emerged as salient predictors of perceptions of the pandemic as disruptive to students’ STEM learning. Specifically, both students and teachers perceived keeping up with coursework, being physically isolated from classmates, and keeping a regular schedule at home to be key barriers. Results further revealed that neither students nor teachers viewed communicating with staff and teachers, losing contact with teachers, or accessing and using technology as barriers. Moreover, school type and gender were important predictors of how students and teachers perceived STEM learning during the pandemic.This research is supported by the Qatar University Office of Research Support, under the grant number QUCG-SESRI20/21-1 for the project entitled “Barriers to Student Participation STEM Education in Qatar”
Energy Efficient Resource Allocation for Demand Intensive Applications in a VLC Based Fog Architecture
In this paper, we propose an energy efficient passive optical network (PON)
architecture for backhaul connectivity in indoor visible light communication
(VLC) systems. The proposed network is used to support a fog computing
architecture designed to allow users with processing demands to access
dedicated fog nodes and idle processing resources in other user devices (UDs)
within the same building. The fog resources within a building complement fog
nodes at the access and metro networks and the central cloud data center. A
mixed integer linear programming (MILP) model is developed to minimize the
total power consumption associated with serving demands over the proposed
architecture. A scenario that considers applications with intensive demands is
examined to evaluate the energy efficiency of the proposed architecture. A
comparison is conducted between allocating the demands in the fog nodes and
serving the demands in the conventional cloud data center. Additionally, the
proposed architecture is compared with an architecture based on state-of-art
Spine-and-Leaf (SL) connectivity. Relative to the SL architecture and serving
all the demands in the cloud, the adoption of the PON-based architecture
achieves 84% and 86% reductions, respectively.Comment: arXiv admin note: substantial text overlap with arXiv:2203.1138
Effects of Thickness on the Metal-Insulator Transition in Free-Standing Vanadium Dioxide Nanocrystals
Controlling solid state phase transitions via external stimuli offers rich physics along with possibilities of unparalleled applications in electronics and optics. The well-known metal-insulator transition (MIT) in vanadium dioxide (VO2) is one instance of such phase transitions emerging from strong electronic correlations. Inducing the MIT using electric field has been investigated extensively for the applications in electrical and ultrafast optical switching. However, as the Thomas-Fermi screening length is very short, for considerable alteration in the material’s properties with electric field induced MIT, crystals below 10 nm are needed. So far, the only way to achieve thin crystals of VO2 has been via epitaxial growth techniques. Yet, stress due to lattice mismatch as well as interdiffusion with the substrate complicate the studies. Here, we show that free-standing vapor-phase grown crystals of VO2 can be milled down to the desired thickness using argon ion-beam milling without compromising their electronic and structural properties. Among our results, we show that even below 4 nm thickness the MIT persists and the transition temperature is lowered in two-terminal devices as the crystal gets thinner. The findings in this Letter can be applied to similar strongly correlated materials to study quantum confinement effects. © 2017 American Chemical Society
Caching Video-on-Demand in Metro and Access Fog Data Centres
This paper examines the utilization of metro fog data centres and access fog datacentres with integrated solar cells and Energy Storage Devices (ESDs) to assist cloud data centres in caching Video-on-Demand content and hence, reduce the networking power consumption. A Mixed Integer Linear Programming (MILP) model is used to optimize the delivery of the content from cloud, metro fog, or access fog datacentres. The results for a range of data centre parameters show that savings by up to 38% in the transport network power consumption can be achieved when VoD is optimally served from fully renewable-powered cloud or metro fog data centres or from access fog data centres with 250 m2 solar cells. Additional 8% savings can be achieved when using ESDs of 100 kWh capacity in the access fog data centres
A systematic review of STEM education research in the GCC countries: trends, gaps and barriers
Abundant research conducted in many countries has underlined the critical role of Science, Technology, Engineering, and Mathematics (STEM) in developing human capital in fields important to a nation’s global competiveness and prosperity. In the Gulf Cooperation Council (GCC) States, recent long-term policy plans emphasize the ever-increasing need of transition to a knowledge-based economy and preparing highly qualified nationals with credentials in STEM fields to meet the current and future needs of the labor market. Yet, despite multiple educational reforms and substantial resources, national and international indicators of student performance still demonstrate insignificant improvement in GCC students’ achievement in STEM subjects. Demonstrably, the GCC youth still lack interest in STEM careers and represent low enrollment rates in STEM fields. This paper presents the results of a systematic review conducted on STEM education research in GCC countries. The review seeks to contribute to the body of the existing STEM literature, explore the factors influencing student participation in STEM, and identify the gaps in STEM education research in those countries
Occurrence of moulds associated with ovine raw milk and cheeses of the Spanish region of Castilla La Mancha
The distribution of mould species was examined at several points of the processing chain in a
Manchego cheese plant and associated dairy farms.
Geotrichum
and
Fusarium
were the most frequent genera isolated in milk samples as well as in 1-month ripened cheeses, evidencing a direct
transfer from raw milk. Conversely, the mycobiota of long-ripened cheeses consisted mainly of
Penicillium
species, which gained entry to the cheese through the air of ripening rooms. This study contributes to the understanding of the dynamics of fungal populations in semihard and hard cheeses,
highlighting that airborne transfer from the stables could have a direct impact on their quality
Educational motivation and students' achievement goal orientations
This paper aims to enhance teachers' understandings of the nature and importance of students' achievement goal orientations in elementary mathematics education. In particular, the study includes a theoretical background about what achievement goal orientation is, and the nature of students' goal orientations. Next, a literature review is provided about the major models identified in goal theory. Then, a discussion is made about why achievement goal orientations are important in mathematics education, supported with the research findings in the literature. Finally, a conclusion is made to summarize the main arguments discussed in the previous parts, with specific suggestions to mathematics teachers
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