Search results for: mixed effects models
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 18716

Search results for: mixed effects models

16436 A Study of Variables Affecting on a Quality Assessment of Mathematics Subject in Thailand by Using Value Added Analysis on TIMSS 2011

Authors: Ruangdech Sirikit

Abstract:

The purposes of this research were to study the variables affecting the quality assessment of mathematics subject in Thailand by using value-added analysis on TIMSS 2011. The data used in this research is the secondary data from the 2011 Trends in International Mathematics and Science Study (TIMSS), collected from 6,124 students in 172 schools from Thailand, studying only mathematics subjects. The data were based on 14 assessment tests of knowledge in mathematics. There were 3 steps of data analysis: 1) To analyze descriptive statistics 2) To estimate competency of students from the assessment of their mathematics proficiency by using MULTILOG program; 3) analyze value added in the model of quality assessment using Value-Added Model with Hierarchical Linear Modeling (HLM) and 2 levels of analysis. The research results were as follows: 1. Student level variables that had significant effects on the competency of students at .01 levels were Parental care, Resources at home, Enjoyment of learning mathematics and Extrinsic motivation in learning mathematics. Variable that had significant effects on the competency of students at .05 levels were Education of parents and self-confident in learning mathematics. 2. School level variable that had significant effects on competency of students at .01 levels was Extra large school. Variable that had significant effects on competency of students at .05 levels was medium school.

Keywords: quality assessment, value-added model, TIMSS, mathematics, Thailand

Procedia PDF Downloads 283
16435 Analysis of Delamination in Drilling of Composite Materials

Authors: Navid Zarif Karimi, Hossein Heidary, Giangiacomo Minak, Mehdi Ahmadi

Abstract:

In this paper analytical model based on the mechanics of oblique cutting, linear elastic fracture mechanics (LEFM) and bending plate theory has been presented to determine the critical feed rate causing delamination in drilling of composite materials. Most of the models in this area used LEFM and bending plate theory; hence, they can only determine the critical thrust force which is an incorporable parameter. In this model by adding cutting oblique mechanics to previous models, critical feed rate has been determined. Also instead of simplification in loading condition, actual thrust force induced by chisel edge and cutting lips on composite plate is modeled.

Keywords: composite material, delamination, drilling, thrust force

Procedia PDF Downloads 515
16434 Monetary Policy and Assets Prices in Nigeria: Testing for the Direction of Relationship

Authors: Jameelah Omolara Yaqub

Abstract:

One of the main reasons for the existence of central bank is that it is believed that central banks have some influence on private sector decisions which will enable the Central Bank to achieve some of its objectives especially that of stable price and economic growth. By the assumption of the New Keynesian theory that prices are fully flexible in the short run, the central bank can temporarily influence real interest rate and, therefore, have an effect on real output in addition to nominal prices. There is, therefore, the need for the Central Bank to monitor, respond to, and influence private sector decisions appropriately. This thus shows that the Central Bank and the private sector will both affect and be affected by each other implying considerable interdependence between the sectors. The interdependence may be simultaneous or not depending on the level of information, readily available and how sensitive prices are to agents’ expectations about the future. The aim of this paper is, therefore, to determine whether the interdependence between asset prices and monetary policy are simultaneous or not and how important is this relationship. Studies on the effects of monetary policy have largely used VAR models to identify the interdependence but most have found small effects of interaction. Some earlier studies have ignored the possibility of simultaneous interdependence while those that have allowed for simultaneous interdependence used data from developed economies only. This study, therefore, extends the literature by using data from a developing economy where information might not be readily available to influence agents’ expectation. In this study, the direction of relationship among variables of interest will be tested by carrying out the Granger causality test. Thereafter, the interaction between asset prices and monetary policy in Nigeria will be tested. Asset prices will be represented by the NSE index as well as real estate prices while monetary policy will be represented by money supply and the MPR respectively. The VAR model will be used to analyse the relationship between the variables in order to take account of potential simultaneity of interdependence. The study will cover the period between 1980 and 2014 due to data availability. It is believed that the outcome of the research will guide monetary policymakers especially the CBN to effectively influence the private sector decisions and thereby achieve its objectives of price stability and economic growth.

Keywords: asset prices, granger causality, monetary policy rate, Nigeria

Procedia PDF Downloads 220
16433 Application of Statistical Linearized Models for Investigations of Digital Dynamic Pulse-Frequency Control Systems

Authors: B. H. Aitchanov, Sh. K. Aitchanova, O. A. Baimuratov

Abstract:

This paper is focused on dynamic pulse-frequency modulation (DPFM) control systems. Currently, the control law based on DPFM control signals is widely used in direct digital control subsystems introduced in the automated control systems of technological processes. Statistical analysis of automatic control systems is reduced to its construction of functional relationships between the statistical characteristics of the errors processes and input processes. Structural and dynamic Volterra models of digital pulse-frequency control systems can be used to develop methods for generating the dependencies, differing accuracy, requiring the amount of information about the statistical characteristics of input processes and computing labor intensity of their use.

Keywords: digital dynamic pulse-frequency control systems, dynamic pulse-frequency modulation, control object, discrete filter, impulse device, microcontroller

Procedia PDF Downloads 495
16432 Six Tropical Medicinal Plants Effects in the Treatment of Prostate Diseases in Forty Different Patients

Authors: T. Nalowa, L. Foncha, S. Eposi

Abstract:

Prostate enlargement, prostate cancer are major global health problems affecting many men as they advance in age. It is highly recommended to encourage older men to get Prostate Specific Antigen test screening frequently. Conventional treatments like radiation, chemotherapy are associated with many side effects. And this situation is a call for concern. Traditional medicine is affordable, easily prepared with little or no side effects and it contains many phytochemicals. The study aims to find the cure for prostate cancer and prostate enlargement by extracting products from plant tissues of specific herbs to determine anti-inflammatory, anti-cancer, and anti-hematuria properties. Descriptive statistical analysis was applied to describe the data process. The commonly used method of preparation was extraction. Overall, 40 patients were classified based on their medical conditions on their underlying user report. Rural communities in Fako are rich sources of plants with medicinal properties. The used plants consequently provide basic information and aid to investigate the cure of prostate cancer and prostate enlargement, with great significance.

Keywords: cancer, enlargement, metastases, prostate

Procedia PDF Downloads 75
16431 Comparative Study Between Continuous Versus Pulsed Ultrasound in Knee Osteoarthritis

Authors: Karim Mohamed Fawzy Ghuiba, Alaa Aldeen Abd Al Hakeem Balbaa, Shams Elbaz

Abstract:

Objectives: To compare between the effects continuous and pulsed ultrasound on pain and function in patient with knee osteoarthritis. Design: Randomized-Single blinded Study. Participants: 6 patients with knee osteoarthritis with mean age 53.66±3.61years, Altman Grade II or III. Interventions: Subjects were randomly assigned into two groups; Group A received continuous ultrasound and Group B received pulsed ultrasound. Outcome measures: Effects of pulsed and continuous ultrasound were evaluated by pain threshold assessed by visual analogue scale (VAS) scores and function assessed by the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) scores. Results: There was no significant decrease in VAS and WOMAC scores in patients treated with pulsed or continuous ultrasound; and there were no significant differences between both groups. Conclusion: there is no difference between the effects of pulsed and continuous ultrasound in pain relief or functional outcome in patients with knee osteoarthritis.

Keywords: knee osteoarthritis, pulsed ultrasound, ultrasound therapy, continuous ultrasound

Procedia PDF Downloads 285
16430 Visual Thinking Routines: A Mixed Methods Approach Applied to Student Teachers at the American University in Dubai

Authors: Alain Gholam

Abstract:

Visual thinking routines are principles based on several theories, approaches, and strategies. Such routines promote thinking skills, call for collaboration and sharing of ideas, and above all, make thinking and learning visible. Visual thinking routines were implemented in the teaching methodology graduate course at the American University in Dubai. The study used mixed methods. It was guided by the following two research questions: 1). To what extent do visual thinking inspire learning in the classroom, and make time for students’ questions, contributions, and thinking? 2). How do visual thinking routines inspire learning in the classroom and make time for students’ questions, contributions, and thinking? Eight student teachers enrolled in the teaching methodology course at the American University in Dubai (Spring 2017) participated in the following study. First, they completed a survey that measured to what degree they believed visual thinking routines inspired learning in the classroom and made time for students’ questions, contributions, and thinking. In order to build on the results from the quantitative phase, the student teachers were next involved in a qualitative data collection phase, where they had to answer the question: How do visual thinking routines inspire learning in the classroom and make time for students’ questions, contributions, and thinking? Results revealed that the implementation of visual thinking routines in the classroom strongly inspire learning in the classroom and make time for students’ questions, contributions, and thinking. In addition, student teachers explained how visual thinking routines allow for organization, variety, thinking, and documentation. As with all original, new, and unique resources, visual thinking routines are not free of challenges. To make the most of this useful and valued resource, educators, need to comprehend, model and spread an awareness of the effective ways of using such routines in the classroom. It is crucial that such routines become part of the curriculum to allow for and document students’ questions, contributions, and thinking.

Keywords: classroom display, student engagement, thinking classroom, visual thinking routines

Procedia PDF Downloads 227
16429 Conjugal Relationship and Reproductive Decision-Making among Couples in Southwest Nigeria

Authors: Peter Olasupo Ogunjuyigbe, Sarafa Shittu

Abstract:

This paper emphasizes the relevance of conjugal relationship and spousal communication towards enhancing men’s involvement in contraceptive use among the Yorubas of South Western Nigeria. An understanding of males influence and the role they play in reproductive decision making can throw better light on mechanisms through which egalitarianness of husband/wife decision making influences contraceptive use. The objective of this study was to investigate how close conjugal relationships can be a good indicator of joint decision making among couples using data derived from a survey conducted in three states of South Western Nigeria. The study sample consisted of five hundred and twenty one (521) male respondents aged 15-59 years and five hundred and forty seven (547) female respondents aged 15-49 years. The study used both quantitative and qualitative approached to elicit information from the respondents. In order that the study would be truly representative of the towns, each of the study locations in the capital cities was divided into four strata: The traditional area, the migrant area, the mixed area (i.e. traditional and migrant), and the elite area. In the rural areas, selection of the respondents was by simple random sampling technique. However, the random selection was made in such a way that all the different parts of the locations were represented. Generally, the data collected were analysed at univariate, bivariate, and multivariate levels. Logistic regression models were employed to examine the interrelationships between male reproductive behaviour, conjugal relationship and contraceptive use. The study indicates that current use of contraceptive is high among this major ethnic group in Nigeria because of the improved level of communication among couples. The problem, however, is that men still have lower exposure rate when it comes to question of family planning information, education and counseling. This has serious implications on fertility regulation in Nigeria.

Keywords: behavior, conjugal, communication, counseling, spouse

Procedia PDF Downloads 137
16428 Study and Conservation of Cultural and Natural Heritages with the Use of Laser Scanner and Processing System for 3D Modeling Spatial Data

Authors: Julia Desiree Velastegui Caceres, Luis Alejandro Velastegui Caceres, Oswaldo Padilla, Eduardo Kirby, Francisco Guerrero, Theofilos Toulkeridis

Abstract:

It is fundamental to conserve sites of natural and cultural heritage with any available technique or existing methodology of preservation in order to sustain them for the following generations. We propose a further skill to protect the actual view of such sites, in which with high technology instrumentation we are able to digitally preserve natural and cultural heritages applied in Ecuador. In this project the use of laser technology is presented for three-dimensional models, with high accuracy in a relatively short period of time. In Ecuador so far, there are not any records on the use and processing of data obtained by this new technological trend. The importance of the project is the description of the methodology of the laser scanner system using the Faro Laser Scanner Focus 3D 120, the method for 3D modeling of geospatial data and the development of virtual environments in the areas of Cultural and Natural Heritage. In order to inform users this trend in technology in which three-dimensional models are generated, the use of such tools has been developed to be able to be displayed in all kinds of digitally formats. The results of the obtained 3D models allows to demonstrate that this technology is extremely useful in these areas, but also indicating that each data campaign needs an individual slightly different proceeding starting with the data capture and processing to obtain finally the chosen virtual environments.

Keywords: laser scanner system, 3D model, cultural heritage, natural heritage

Procedia PDF Downloads 306
16427 Marginalized Two-Part Joint Models for Generalized Gamma Family of Distributions

Authors: Mohadeseh Shojaei Shahrokhabadi, Ding-Geng (Din) Chen

Abstract:

Positive continuous outcomes with a substantial number of zero values and incomplete longitudinal follow-up are quite common in medical cost data. To jointly model semi-continuous longitudinal cost data and survival data and to provide marginalized covariate effect estimates, a marginalized two-part joint model (MTJM) has been developed for outcome variables with lognormal distributions. In this paper, we propose MTJM models for outcome variables from a generalized gamma (GG) family of distributions. The GG distribution constitutes a general family that includes approximately all of the most frequently used distributions like the Gamma, Exponential, Weibull, and Log Normal. In the proposed MTJM-GG model, the conditional mean from a conventional two-part model with a three-parameter GG distribution is parameterized to provide the marginal interpretation for regression coefficients. In addition, MTJM-gamma and MTJM-Weibull are developed as special cases of MTJM-GG. To illustrate the applicability of the MTJM-GG, we applied the model to a set of real electronic health record data recently collected in Iran, and we provided SAS code for application. The simulation results showed that when the outcome distribution is unknown or misspecified, which is usually the case in real data sets, the MTJM-GG consistently outperforms other models. The GG family of distribution facilitates estimating a model with improved fit over the MTJM-gamma, standard Weibull, or Log-Normal distributions.

Keywords: marginalized two-part model, zero-inflated, right-skewed, semi-continuous, generalized gamma

Procedia PDF Downloads 176
16426 Deprivation of Visual Information Affects Differently the Gait Cycle in Children with Different Level of Motor Competence

Authors: Miriam Palomo-Nieto, Adrian Agricola, Rudolf Psotta, Reza Abdollahipour, Ludvik Valtr

Abstract:

The importance of vision and the visual control of movement have been labeled in the literature related to motor control and many studies have demonstrated that children with low motor competence may rely more heavily on vision to perform movements than their typically developing peers. The aim of the study was to highlight the effects of different visual conditions on motor performance during walking in children with different levels of motor coordination. Participants (n = 32, mean age = 8.5 years sd. ± 0.5) were divided into two groups: typical development (TD) and low motor coordination (LMC) based on the scores of the Movement Assessment Battery for Children (MABC-2). They were asked to walk along a 10 meters walkway where the Optojump-Next instrument was installed in a portable laboratory (15 x 3 m), which allows that all participants had the same visual information. They walked in self-selected speed under four visual conditions: full vision (FV), limited vision 100 ms (LV-100), limited vision 150 ms (LV-150) and non-vision (NV). For visual occlusion participants were equipped with Plato Goggles that shut for 100 and 150 ms, respectively, within each 2 sec. Data were analyzed in a two-way mixed-effect ANOVA including 2 (TD vs. LMC) x 4 (FV, LV-100, LV-150 & NV) with repeated-measures on the last factor (p ≤.05). Results indicated that TD children walked faster and with longer normalized steps length and strides than LMC children. For TD children the percentage of the single support and swing time were higher than for low motor competence children. However, the percentage of load response and pre swing was higher in the low motor competence children rather than the TD children. These findings indicated that through walking we could be able to identify different levels of motor coordination in children. Likewise, LMC children showed shorter percentages in those parameters regarding only one leg support, supporting the idea of balance problems.

Keywords: visual information, motor performance, walking pattern, optojump

Procedia PDF Downloads 574
16425 Functions of Public Policy in Private International Law

Authors: Fedorova Elena

Abstract:

In this article, we draw a distinction between two important functions of public policy in private international law. The first function is widely recognized and relates to the prevention of application of foreign laws and enforcement of foreign court judgments whenever their effects are incompatible with the domestic legal system of the forum. This effectively protects sovereign rights of the forum state as it allows to resist against the undesirable effects of foreign law-making and law-enforcement policies. The second function is less obvious, but not less important. As the internal private legal relationships, international private relationships are usually governed by rules of public policy, to which the parties can not derogate by mutual agreement. Thefore, for international private law relations public policy has a different function than previously mentioned: in this case, the public policy acts as a defense against unacceptable effects of the party autonomy. Thus, this second function of public policy consists in the limitation of the party autonomy wich effects would be unacceptable for the local legal system. In the frame of this second function the author will analyse two types of public policy which can limit the party autonomy: « substantial » public policy (which regulates the substance of international legal relationship) and « conflictual » public policy (which regulates the party autonomy to choose the law applicable for the substance of relationship). The author provides an analysis of these functions of the public policy in the field of international contract law because of the important role of the principle of party autonomy for international contract relations.

Keywords: public policy, general theory of private international law, substantial public policy, conflictual public policy

Procedia PDF Downloads 573
16424 Insecticidal and Antifeedant Activity of Rosemary´s (Rosmarinus Officinalis L.) Different Extracts on Cotton Bollworm Helicoverpa Armigera Hubner

Authors: Monireh Movahedi

Abstract:

Considering undesirable effects of chemical insecticides on environment and human health, most studies focused on insecticidal effects of plant materials. Here, the insecticidal effects of methanol, ethylacetat and n-Hexan extracts of Rosmarinus officinalis L. on larval stage of the cotton bollworm were studied. From each extract, six concentrations, including 5, 10, 20, 40 and 60 mg/ml were prepared and added on larval artificial diet. Moreover, solution of distilled water and tween 2% considered as check treatment. All experiments were done in laboratory temperature of 25±3 ºC, RH =50±10% and natural photoperiod during growing season. Each treatment had four replications and each replication carried out on 10 first instar larva with <24h age. Larval mortality was recorded 3 and 7 days after treat. Based on results, LC50 of methanol, ethylacetat and n-Hexan extracts of R. officinalis were 2.78, 15.87 and 15.70 ml/mg, respectively. On the other hand, antifeedant effect of methanol, ethylacetat and n-Hexan for R. officinalis estimated as 43.13%, 55.11% and 9.19%, respectively. All the obtained results revealed that methanol and ethylacetat extracts of R. officinalis are effective extracts for controlling the cotton bollworm population.

Keywords: Helocoverpa armigera, Rosemarinus officinalis, extract, methanol, ethylacetat, n-Hexan

Procedia PDF Downloads 171
16423 Investigation Effect of External Flow to Exhaust Gas Flow at Heavy Commercial Vehicle with CFD

Authors: F. Kantaş, D. Boyacı, C. Dinç

Abstract:

Exhaust systems plays an important role in thermal heat management. Exhaust manifold picks burned gas from engine and exhaust pipes transmit exhaust gas to muffler, exhaust gas is reacted chemically to avoid noxious gas and sound is reduced in muffler then gas is threw out with tail pipe from muffler. Exhaust gas flows out from tail pipe and this hot gas flows to many parts that available around tail pipe and muffler, like spare tire, transmission, pipes etc. These parts are heated by hot exhaust gas. Also vehicle on ride, external flow effects exhaust gas flow and exhaust gas behavior is changed. It's impossible to understand which parts are heated by hot exhaust gas in tests. To understand this phenomena, exhaust gas flow is solved in CFD also external flow due to vehicle movement must be solved with exhaust gas flow. Because external flow effects exhaust gas flow behavior with many parameters. This paper investigates external flow effects exhaust gas flow behavior and other critical parameters effect exhaust gas flow behavior, like different tail pipe design, exhaust gas mass flow in critic vehicle driving situations.

Keywords: exhaust, gas flow, vehicle, external flow

Procedia PDF Downloads 448
16422 Temperature Fields in a Channel Partially-Filled by Porous Material with Internal Heat Generations: On Exact Solution

Authors: Yasser Mahmoudi, Nader Karimi

Abstract:

The present work examines analytically the effect internal heat generation on temperature fields in a channel partially-filled with a porous under local thermal non-equilibrium condition. The Darcy-Brinkman model is used to represent the fluid transport through the porous material. Two fundamental models (models A and B) represent the thermal boundary conditions at the interface between the porous medium and the clear region. The governing equations of the problem are manipulated, and for each interface model, exact solutions for the solid and fluid temperature fields are developed. These solutions incorporate the porous material thickness, Biot number, fluid to solid thermal conductivity ratio Darcy number, as the non-dimensional energy terms in fluid and solid as parameters. Results show that considering any of the two models and under zero or negative heat generation (heat sink) and for any Darcy number, an increase in the porous thickness increases the amount of heat flux transferred to the porous region. The obtained results are applicable to the analysis of complex porous media incorporating internal heat generation, such as heat transfer enhancement (THE), tumor ablation in biological tissues and porous radiant burners (PRBs).

Keywords: porous media, local thermal non-equilibrium, forced convection, heat transfer, exact solution, internal heat generation

Procedia PDF Downloads 460
16421 Young Social Beings: An Investigation into the Social Interactions and Relationships of a Year Five Class

Authors: A. Sewell

Abstract:

The paper reports a research project which investigated the social interactions of nine to ten-year-olds in a mainstream primary school. The project implemented an adaption of a whole class, behavioural intervention known as 'The Good Behaviour Game (TGBG)'. TGBG is an evidence-based intervention traditionally used to reduce low-level disruptive behaviours in a classroom setting. TGBG was adapted to encourage pupil’s engagement in pro-social behaviour during lessons. A mixed methods research design was employed to evaluate intervention effects and pupil’s perceptions of their social interactions and relationships with others. Single-case research design was used to evaluate behaviour change, and Personal Construct Psychology (PCP) repertory grids were used to explore pupil’s perceptions. The findings demonstrated that TGBG could be successfully adapted to positively influence pupil’s engagement in pro-social behaviours. The findings from the PCP repertory grid interviews revealed the complexities of how children construct their social interactions and relationships with others, and how an understanding of these could be used to design better social skills interventions. It is concluded that TGBG is a cost-effective, simple to implement intervention for promoting positive social interactions and relationships at the whole class level. The paper presents the aims, design, findings, and conclusions of the study in further detail and relates limitations and potential future extensions of the research. The outcomes have direct application and relevance for practitioners interested in children’s social development and how to promote positive outcomes in this critical aspect of childhood.

Keywords: social skills, social development, social competency, the good behaviour game

Procedia PDF Downloads 170
16420 Physical Characterization of a Watershed for Correlation with Parameters of Thomas Hydrological Model and Its Application in Iber Hidrodinamic Model

Authors: Carlos Caro, Ernest Blade, Nestor Rojas

Abstract:

This study determined the relationship between basic geo-technical parameters and parameters of the hydro logical model Thomas for water balance of rural watersheds, as a methodological calibration application, applicable in distributed models as IBER model, which represents a distributed system simulation models for unsteady flow numerical free surface. There was an exploration in 25 points (on 15 sub) basin of Rio Piedras (Boy.) obtaining soil samples, to which geo-technical characterization was performed by laboratory tests. Thomas model has a physical characterization of the input area by only four parameters (a, b, c, d). Achieve measurable relationship between geo technical parameters and 4 values of hydro logical parameters helps to determine subsurface, underground and surface flow more agile manner. It is intended in this way to reach some solutions regarding limits initial model parameters on the basis of Thomas geo-technical characterization. In hydro geological models of rural watersheds, calibration is an important process in the characterization of the study area. This step can require a significant computational cost and time, especially if the initial values or parameters before calibration are outside of the geo-technical reality. A better approach in these initial values means optimization of these process through a geo-technical materials area, where is obtained an important approach to the study as in the starting range of variation for the calibration parameters.

Keywords: distributed hydrology, hydrological and geotechnical characterization, Iber model

Procedia PDF Downloads 522
16419 Energy Performance of Buildings Due to Downscaled Seasonal Models

Authors: Anastasia K. Eleftheriadou, Athanasios Sfetsos, Nikolaos Gounaris

Abstract:

The present work examines the suitability of a seasonal forecasting model downscaled with a very high spatial resolution in order to assess the energy performance and requirements of buildings. The application of the developed model is applied on Greece for a period and with a forecast horizon of 5 months in the future. Greece, as a country in the middle of a financial crisis and facing serious societal challenges, is also very sensitive to climate changes. The commonly used method for the correlation of climate change with the buildings energy consumption is the concept of Degree Days (DD). This method can be applied to heating and cooling systems for a better management of environmental, economic and energy crisis, and can be used as medium (3-6 months) planning tools in order to predict the building needs and country’s requirements for residential energy use.

Keywords: downscaled seasonal models, degree days, energy performance

Procedia PDF Downloads 453
16418 Expected Present Value of Losses in the Computation of Optimum Seismic Design Parameters

Authors: J. García-Pérez

Abstract:

An approach to compute optimum seismic design parameters is presented. It is based on the optimization of the expected present value of the total cost, which includes the initial cost of structures as well as the cost due to earthquakes. Different types of seismicity models are considered, including one for characteristic earthquakes. Uncertainties are included in some variables to observe the influence on optimum values. Optimum seismic design coefficients are computed for three different structural types representing high, medium and low rise buildings, located near and far from the seismic sources. Ordinary and important structures are considered in the analysis. The results of optimum values show an important influence of seismicity models as well as of uncertainties on the variables.

Keywords: importance factors, optimum parameters, seismic losses, seismic risk, total cost

Procedia PDF Downloads 284
16417 Analyzing the Use of Augmented and Virtual Reality to Teach Social Skills to Students with Autism

Authors: Maggie Mosher, Adam Carreon, Sean Smith

Abstract:

A systematic literature review was conducted to explore the evidence base on the use of augmented reality (AR), virtual reality (VR), mixed reality (MR), and extended reality (XR) to present social skill instruction to school-age students with autism spectrum disorder (ASD). Specifically, the systematic review focus was on a. the participants and intervention agents using AR, VR, MR, and XR for social skill acquisition b. the social skills taught through these mediums and c. the social validity measures (i.e., goals, procedures, and outcomes) reported in these studies. Forty-one articles met the inclusion criteria. Researchers in six studies taught social skills to students through AR, in 27 studies through non-immersive VR, and in 10 studies through immersive VR. No studies used MR or XR. The primary targeted social skills were relationship skills, emotion recognition, social awareness, cooperation, and executive functioning. An intervention to improve many social skills was implemented by 73% of researchers, 17% taught a single skill, and 10% did not clearly state the targeted skill. The intervention was considered effective in 26 of the 41 studies (63%), not effective in four studies (10%), and 11 studies (27%) reported mixed results. No researchers reported information for all 17 social validity indicators. The social validity indicators reported by researchers ranged from two to 14. Social validity measures on the feelings toward and use of the technology were provided in 22 studies (54%). Findings indicated both AR and VR are promising platforms for providing social skill instruction to students with ASD. Studies utilizing this technology show a number of social validity indicators. However, the limited information provided on the various interventions, participant characteristics, and validity measures, offers insufficient evidence of the impact of these technologies in teaching social skills to students with ASD. Future research should develop a protocol for training treatment agents to assess the role of different variables (i.e., whether agents are customizing content, monitoring student learning, using intervention specific vocabulary in their day to day instruction). Sustainability may be increased by providing training in the technology to both treatment agents and participants. Providing scripts of instruction occurring within the intervention would provide the needed information to determine the primary method of teaching within the intervention. These variables play a role in maintenance and generalization of the social skills. Understanding the type of feedback provided would help researchers determine if students were able to feel rewarded for progressing through the scenarios or if students require rewarding aspects within the intervention (i.e., badges, trophies). AR has the potential to generalize instruction and VR has the potential for providing a practice environment for performance deficits. Combining these two technologies into a mixed reality intervention may provide a more cohesive and effective intervention.

Keywords: autism, augmented reality, social and emotional learning, social skills, virtual reality

Procedia PDF Downloads 109
16416 Behaviour and Design of the Candle-Loc Inter-Module Connection in High-Rise Modular Buildings under Seismic Action

Authors: Alessandro Marzucchini, Yie Sue Chua, Andrew Lian, Richard Shonn Mills

Abstract:

A unique, fast and easy installed inter-module connection named Candle-Loc was developed and applied in several high-rise steel and reinforced concrete modular buildings in Singapore and Hong Kong, China. However, its effect on the global behaviour of modular buildings in high seismic zones was not studied. Therefore, the design concept and the structural performance of each component in this connection was investigated through analytical approach. Response spectrum, linear time-history, and nonlinear time-history analyses were conducted to investigate the effects of the different joint models of the Candle-Loc in the global analysis of high-rise buildings under high seismic loads. It is found that it is important to assess the level of plasticity developed in the inter-module connection under high seismic loads. The ductility of the lateral force resisting system influences the amount of load taken by the inter-module connections.

Keywords: high-rise, inter-module connection, nonlinear, seismic, time-history analysis

Procedia PDF Downloads 202
16415 Enhanced Flight Dynamics Model to Simulate the Aircraft Response to Gust Encounters

Authors: Castells Pau, Poetsch Christophe

Abstract:

The effect of gust and turbulence encounters on aircraft is a wide field of study which allows different approaches, from high-fidelity multidisciplinary simulations to more simplified models adapted to industrial applications. The typical main goal is to predict the gust loads on the aircraft in order to ensure a safe design and achieve certification. Another topic widely studied is the gust loads reduction through an active control law. The impact of gusts on aircraft handling qualities is of interest as well in the analysis of in-service events so as to evaluate the aircraft response and the performance of the flight control laws. Traditionally, gust loads and handling qualities are addressed separately with different models adapted to the specific needs of each discipline. In this paper, an assessment of the differences between both models is presented and a strategy to better account for the physics of gust encounters in a typical flight dynamics model is proposed based on the model used for gust loads analysis. The applied corrections aim to capture the gust unsteady aerodynamics and propagation as well as the effect of dynamic flexibility at low frequencies. Results from the gust loads model at different flight conditions and measures from real events are used for validation. An assessment of a possible extension of steady aerodynamic nonlinearities to low frequency range is also addressed. The proposed corrections provide meaningful means to evaluate the performance and possible adjustments of the flight control laws.

Keywords: flight dynamics, gust loads, handling qualities, unsteady aerodynamics

Procedia PDF Downloads 147
16414 Numerical Model of Crude Glycerol Autothermal Reforming to Hydrogen-Rich Syngas

Authors: A. Odoom, A. Salama, H. Ibrahim

Abstract:

Hydrogen is a clean source of energy for power production and transportation. The main source of hydrogen in this research is biodiesel. Glycerol also called glycerine is a by-product of biodiesel production by transesterification of vegetable oils and methanol. This is a reliable and environmentally-friendly source of hydrogen production than fossil fuels. A typical composition of crude glycerol comprises of glycerol, water, organic and inorganic salts, soap, methanol and small amounts of glycerides. Crude glycerol has limited industrial application due to its low purity thus, the usage of crude glycerol can significantly enhance the sustainability and production of biodiesel. Reforming techniques is an approach for hydrogen production mainly Steam Reforming (SR), Autothermal Reforming (ATR) and Partial Oxidation Reforming (POR). SR produces high hydrogen conversions and yield but is highly endothermic whereas POR is exothermic. On the downside, PO yields lower hydrogen as well as large amount of side reactions. ATR which is a fusion of partial oxidation reforming and steam reforming is thermally neutral because net reactor heat duty is zero. It has relatively high hydrogen yield, selectivity as well as limits coke formation. The complex chemical processes that take place during the production phases makes it relatively difficult to construct a reliable and robust numerical model. Numerical model is a tool to mimic reality and provide insight into the influence of the parameters. In this work, we introduce a finite volume numerical study for an 'in-house' lab-scale experiment of ATR. Previous numerical studies on this process have considered either using Comsol or nodal finite difference analysis. Since Comsol is a commercial package which is not readily available everywhere and lab-scale experiment can be considered well mixed in the radial direction. One spatial dimension suffices to capture the essential feature of ATR, in this work, we consider developing our own numerical approach using MATLAB. A continuum fixed bed reactor is modelled using MATLAB with both pseudo homogeneous and heterogeneous models. The drawback of nodal finite difference formulation is that it is not locally conservative which means that materials and momenta can be generated inside the domain as an artifact of the discretization. Control volume, on the other hand, is locally conservative and suites very well problems where materials are generated and consumed inside the domain. In this work, species mass balance, Darcy’s equation and energy equations are solved using operator splitting technique. Therefore, diffusion-like terms are discretized implicitly while advection-like terms are discretized explicitly. An upwind scheme is adapted for the advection term to ensure accuracy and positivity. Comparisons with the experimental data show very good agreements which build confidence in our modeling approach. The models obtained were validated and optimized for better results.

Keywords: autothermal reforming, crude glycerol, hydrogen, numerical model

Procedia PDF Downloads 140
16413 Analysis of Network Performance Using Aspect of Quantum Cryptography

Authors: Nisarg A. Patel, Hiren B. Patel

Abstract:

Quantum cryptography is described as a point-to-point secure key generation technology that has emerged in recent times in providing absolute security. Researchers have started studying new innovative approaches to exploit the security of Quantum Key Distribution (QKD) for a large-scale communication system. A number of approaches and models for utilization of QKD for secure communication have been developed. The uncertainty principle in quantum mechanics created a new paradigm for QKD. One of the approaches for use of QKD involved network fashioned security. The main goal was point-to-point Quantum network that exploited QKD technology for end-to-end network security via high speed QKD. Other approaches and models equipped with QKD in network fashion are introduced in the literature as. A different approach that this paper deals with is using QKD in existing protocols, which are widely used on the Internet to enhance security with main objective of unconditional security. Our work is towards the analysis of the QKD in Mobile ad-hoc network (MANET).

Keywords: cryptography, networking, quantum, encryption and decryption

Procedia PDF Downloads 184
16412 Critical Evaluation of the Effects of Conditionalities and Structural Adjustments on the Poor and Developing Countries

Authors: Kazi Rafikoddin

Abstract:

Conditionality refers to a precondition for getting external funds from IMF or WB by giving consent for implementation of the program of economic or political reforms especially relating to open economies. These are put forth under the label of structural adjustment. It is a kind of challenge on the part of borrowing government to exercise balance between the domestic obligations and the expectations of external funding agencies. Countries have to take loans under certain criteria and regulations because better loans are often not readily available. Therefore taking loans and renewing them to pay the same with new interest rates and conditions makes the governments entangled in the circle of debt. They are forced to compete with well-established multinational companies. If their access to industrialized countries' markets is impaired through protectionism, the developed world will be condemning the indebted nations to perpetual financial crisis. On the other hand, the ability to sell their goods free in the world market is reduced through the introduction of Structural Adjustment Programmes. Although there are examples of positive effects on certain economies like India, some Third World, and poor countries have experienced the ire of these remedies. This paper tries to find out the effects of SAPs on some borrowing countries.

Keywords: IMF, world bank, conditionalities, SAPs, Third World Countries

Procedia PDF Downloads 201
16411 Effects of Rising Cost of Building Materials in Nigeria: A Case Study of Adamawa State

Authors: Ibrahim Yerima Gwalem, Jamila Ahmed Buhari

Abstract:

In recent years, there has been an alarming rate of increase in the costs of building materials in Nigeria, and this ugly phenomenon threatens the contributions of the construction industry in national development. The purpose of this study was to assess the effects of the rising cost of building materials in Adamawa State Nigeria. Four research questions in line with the purpose of the study were raised to guide the study. Two null hypotheses were formulated and tested at 0.05 level of significance. The study adopted a survey research design. The population of the study comprises registered contractors, registered builders, selected merchants, and consultants in Adamawa state. Data were collected using researcher designed instrument tagged effects of the rising cost of building materials questionnaire (ERCBMQ). The instrument was subjected to face and content validation by two experts, one from Modibbo Adama University of Technology Yola and the other from Federal Polytechnic Mubi. The reliability of the instrument was determined by the Cronbach Alpha method and yielded a reliability index of 0.85 high enough to ascertain the reliability. Data collected from a field survey of 2019 was analyzed using mean and percentage. The means of the prices were used in the calculations of price indices and rates of inflation on building materials. Findings revealed that factors responsible for the rising cost of building materials are the exchange rate of the Nigeria Naira with a mean rating (MR) = 4.4; cost of fuel and power supply, MR = 4.3; and changes in government policies and legislation, MR = 4.2, while fluctuations in the construction cost with MR = 2.8; reduced volume of construction output, MR = 2.52; and risk of project abandonment, MRA = 2.51, were the three effects. The study concluded that adverse effects could result in a downward effect on the contributions of the construction industries on the gross domestic product (GDP) in the nation’s economy. Among the recommendations proffered include that the government should formulate a policy that will play down the agitations on the use of imported building materials by encouraging research in the production of local building materials.

Keywords: effects, rising, cost, building, materials

Procedia PDF Downloads 139
16410 Exploration of Critical Success Factors in Business and Management in Artificial Intelligence Era

Authors: Najah Kalifah Almazmomi

Abstract:

In the time of artificial intelligence (AI), there is a need to know the determinants of success in business management, which are taking on a new dimension. This research purports to scrutinize the Critical Success Factors (CSFs) that drive and ignite the fire of success to help uncover the subtle and profound dynamics that might be operative in organizations. By means of a systematic literature review and a number of empirical methods, the paper is aimed at determining and assessing the key aspects of CSFs, putting emphasis on their role and meaning in the context of AI technology adoption. Some central features such as leadership ways, innovation models, strategic thinking methodologies, organizational culture transformations, and human resource management approaches are compared and contrasted with the AI-driven revolution. Additionally, this research will explore the interactive effects of these factors and their joint impact on the success, survival, and flexibility of a business in the current environment, which is changing due to AI development. Through the use of different qualitative and quantitative methodologies, the research concludes that the findings are significant in understanding the relative roles of individual CSFs and in studying the interactions between them in such an AI-enabled business environment.

Keywords: critical success factors, business and management, artificial intelligence, leadership strategies

Procedia PDF Downloads 37
16409 Effects of Conjugated Linoleic Acid (CLA) on Hormones and Factors Involved in Murine Ovulation

Authors: Leila Karshenas, Hamidreza Khodaei, Behnaz Mahdavi

Abstract:

Ovulation is a physiologic process with an inflammatory response that depends on a coordinated activity of gonadotropins and steroid hormones, as well as inflammatory mediators such as cytokines, prostaglandins, leptin, nitric oxide (NO), etc. Conjugated linoleic acid (CLA) is composed of polyunsaturated fatty acids (PUFA) found in dairy products, beef and lamb. There is strong evidence that dietary CLA affects mediators involved in ovulation. The aim of this study was to determine the effects of different doses of dietary CLA on systemic and local hormones and factors involved in ovulation. In this case-control study, 80 (50±2-day old) female mice were randomly divided into four groups (C as the controls and T1, T2 and T3 as the treatment groups). There were four replicates in each group and there were five mice in every replicate (20 mice, in total). The mice in the control group were fed with no CLA in their diet but the ones in the treatment group received 0.1, 0.3 and 0.5g/kg of CLA (replacing corn oil in the diet), respectively for 120 days. Later on, blood samples were obtained from the tails of animals that displayed estrus signs and estradiol (E2), progesterone (P4), LH, FSH, NO, leptin and TNFα were measured. Furthermore, the effects of CLA on the ovarian production of prostaglandins (PGs) and NO were investigated. The data were analyzed by SAS software.CLA significantly decreased serum levels of FSH (p<0.05), LH, estradiol, NO, leptin and TNFα (p<0.01). In addition, CLA decreased progesterone levels but this effect was statistically insignificant. The significantly negative effects of CLA were seen on the ovarian production of PGE2 and PGF2α (p<0.01).It seems that CLA may play an effective role in reducing the ovulation rate in mice as CLA adversely affected female reproduction and it had negative effects on systemic and local hormones involved in ovulation.

Keywords: conjugated linoleic acid, nitric oxide, ovary, ovulation, prostaglandin, gonadotropin

Procedia PDF Downloads 301
16408 A Mixed Methods Research Design for the Development of the Xenia Higher Education Institutions' Inclusiveness Index

Authors: Achilles Kameas, Eleni Georgakakou, Anna Lisa Amodeo, Aideen Quilty, Aisling Malone, Roberta Albertazzi, Moises Carmona, Concetta Esposito, Ruben David Fernandez Carrasco, Carmela Ferrara, Francesco Garzillo, Mojca Pusnik, Maria Cristina Scarano

Abstract:

While researchers, especially in academia, study and research the phenomena of inclusion of sexual minority and gender marginalized groups, seldom the European Higher Education Institutions (HEI) act on lowering the cultural and educational barriers to their proactive inclusion. The challenge in European HEIs is that gender, and sexual orientation discrimination remains an issue not adequately addressed. Following a mixed methods research design of quantitative and qualitative research techniques and tools, which is applied in five (5) European countries (Italy, Greece, Ireland, Slovenia, and Spain) and that combines desk research, evaluation, and weighting processes for a Matrix-based on Objective indicators and Survey for students and staff of the HEI to gauge the perception of inclusiveness in the HEI context, XENIA HEI Inclusiveness Index is an instrument that will allow universities to gauge and assess their inclusiveness in the domain of discrimination and exclusion based on gender identity and sexual orientation. The index will allow capturing the depth and reach of policies, programmes, and initiatives of HEIs in tackling the phenomena and dynamics of exclusion of LGBT+ (lesbian, gay, bisexual, trans, and other marginalized groups on the basis of gender and sexual identity) and cisgender women exposed to the risk of discrimination.

Keywords: gender identity, higher education, LGBT+ rights, XENIA inclusiveness index

Procedia PDF Downloads 163
16407 Flexural Strengthening of Steel Beams Using Fiber Reinforced Polymers

Authors: Sally Hosny, Mona G. Ibrahim, N. K. Hassan

Abstract:

Fiber reinforced polymers (FRP) is one of the most environmentally method for strengthening and retrofitting steel structure buildings. The behaviour of flexural strengthened steel I-beams using FRP was investigated. The finite element (FE) models were developed using ANSYS® as verification cases to simulate the experimental behaviour of using FRP strips to flexure strengthen steel I-beam. Two experimental studies were selected for verification; first examined the effect of different thicknesses and modulus of elasticity while the second studied the effect of applying different carbon fiber reinforced polymers (CFRP) bond lengths. The proposed FE models were in good agreement with the experimental results in terms of failure modes, load bearing capacities and strain distribution on CFRP strips. The verified FE models can be utilized to conduct a parametric study where various widths (40, 50, 60, 70 and 80 mm), thickness (1.2, 2 and 4 mm) and lengths (1500, 1700 and 1800 mm) of CFRP were analyzed. The results presented clearly revealed that the load bearing capacity was significantly increased (+7%) when the width and thickness were increased. However, load bearing capacity was slightly affected using longer CFRP strips. Moreover, applying another glass fiber reinforced polymers (GFRP) of 1500 mm in length, 50 mm in width and thicknesses of 1.2, 2 and 4 mm were investigated. Load bearing capacity of strengthened I-beams using GFRP is less than CFRP by average 8%. Statistical analysis has been conducted using Minitab®.

Keywords: FRP, strengthened steel I-beams, flexural, FEM, ANSYS

Procedia PDF Downloads 279