Search results for: longitudinal fins
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 804

Search results for: longitudinal fins

444 Detection of Concrete Reinforcement Damage Using Piezoelectric Materials: Analytical and Experimental Study

Authors: C. P. Providakis, G. M. Angeli, M. J. Favvata, N. A. Papadopoulos, C. E. Chalioris, C. G. Karayannis

Abstract:

An effort for the detection of damages in the reinforcement bars of reinforced concrete members using PZTs is presented. The damage can be the result of excessive elongation of the steel bar due to steel yielding or due to local steel corrosion. In both cases the damage is simulated by considering reduced diameter of the rebar along the damaged part of its length. An integration approach based on both electromechanical admittance methodology and guided wave propagation technique is used to evaluate the artificial damage on the examined longitudinal steel bar. Two actuator PZTs and a sensor PZT are considered to be bonded on the examined steel bar. The admittance of the Sensor PZT is calculated using COMSOL 3.4a. Fast Furrier Transformation for a better evaluation of the results is employed. An effort for the quantification of the damage detection using the root mean square deviation (RMSD) between the healthy condition and damage state of the sensor PZT is attempted. The numerical value of the RSMD yields a level for the difference between the healthy and the damaged admittance computation indicating this way the presence of damage in the structure. Experimental measurements are also presented.

Keywords: concrete reinforcement, damage detection, electromechanical admittance, experimental measurements, finite element method, guided waves, PZT

Procedia PDF Downloads 231
443 Detection of Concrete Reinforcement Damage Using Piezoelectric Materials: Analytical and Experimental Study

Authors: C. P. Providakis, G. M. Angeli, M. J. Favvata, N. A. Papadopoulos, C. E. Chalioris, C. G. Karayannis

Abstract:

An effort for the detection of damages in the reinforcement bars of reinforced concrete members using PZTs is presented. The damage can be the result of excessive elongation of the steel bar due to steel yielding or due to local steel corrosion. In both cases the damage is simulated by considering reduced diameter of the rebar along the damaged part of its length. An integration approach based on both electro-mechanical admittance methodology and guided wave propagation technique is used to evaluate the artificial damage on the examined longitudinal steel bar. Two actuator PZTs and a sensor PZT are considered to be bonded on the examined steel bar. The admittance of the Sensor PZT is calculated using COMSOL 3.4a. Fast Furrier Transformation for a better evaluation of the results is employed. An effort for the quantification of the damage detection using the root mean square deviation (RMSD) between the healthy condition and damage state of the sensor PZT is attempted. The numerical value of the RSMD yields a level for the difference between the healthy and the damaged admittance computation indicating this way the presence of damage in the structure. Experimental measurements are also presented.

Keywords: concrete reinforcement, damage detection, electromechanical admittance, experimental measurements, finite element method, guided waves, PZT

Procedia PDF Downloads 265
442 Modeling and Performance Evaluation of an Urban Corridor under Mixed Traffic Flow Condition

Authors: Kavitha Madhu, Karthik K. Srinivasan, R. Sivanandan

Abstract:

Indian traffic can be considered as mixed and heterogeneous due to the presence of various types of vehicles that operate with weak lane discipline. Consequently, vehicles can position themselves anywhere in the traffic stream depending on availability of gaps. The choice of lateral positioning is an important component in representing and characterizing mixed traffic. The field data provides evidence that the trajectory of vehicles in Indian urban roads have significantly varying longitudinal and lateral components. Further, the notion of headway which is widely used for homogeneous traffic simulation is not well defined in conditions lacking lane discipline. From field data it is clear that following is not strict as in homogeneous and lane disciplined conditions and neighbouring vehicles ahead of a given vehicle and those adjacent to it could also influence the subject vehicles choice of position, speed and acceleration. Given these empirical features, the suitability of using headway distributions to characterize mixed traffic in Indian cities is questionable, and needs to be modified appropriately. To address these issues, this paper attempts to analyze the time gap distribution between consecutive vehicles (in a time-sense) crossing a section of roadway. More specifically, to characterize the complex interactions noted above, the influence of composition, manoeuvre types, and lateral placement characteristics on time gap distribution is quantified in this paper. The developed model is used for evaluating various performance measures such as link speed, midblock delay and intersection delay which further helps to characterise the vehicular fuel consumption and emission on urban roads of India. Identifying and analyzing exact interactions between various classes of vehicles in the traffic stream is essential for increasing the accuracy and realism of microscopic traffic flow modelling. In this regard, this study aims to develop and analyze time gap distribution models and quantify it by lead lag pair, manoeuvre type and lateral position characteristics in heterogeneous non-lane based traffic. Once the modelling scheme is developed, this can be used for estimating the vehicle kilometres travelled for the entire traffic system which helps to determine the vehicular fuel consumption and emission. The approach to this objective involves: data collection, statistical modelling and parameter estimation, simulation using calibrated time-gap distribution and its validation, empirical analysis of simulation result and associated traffic flow parameters, and application to analyze illustrative traffic policies. In particular, video graphic methods are used for data extraction from urban mid-block sections in Chennai, where the data comprises of vehicle type, vehicle position (both longitudinal and lateral), speed and time gap. Statistical tests are carried out to compare the simulated data with the actual data and the model performance is evaluated. The effect of integration of above mentioned factors in vehicle generation is studied by comparing the performance measures like density, speed, flow, capacity, area occupancy etc under various traffic conditions and policies. The implications of the quantified distributions and simulation model for estimating the PCU (Passenger Car Units), capacity and level of service of the system are also discussed.

Keywords: lateral movement, mixed traffic condition, simulation modeling, vehicle following models

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441 User Perceptions Deviation from the Producers’ Intended Meaning of a Healthcare Innovation

Authors: Helle Nissen

Abstract:

Physical objects surrounding people in healthcare environments are carriers of institutional logics materialized into the objects by its producers. However, institutional logics research lacks to inform us how logics become materialized and are perceived by producers vs. users of an object. The study is based on a 3-year longitudinal case study of a Danish Public Private Innovation project aiming to co-create an innovative healthcare bed commercialized to public psychiatric hospitals. The producers are a private metal firm and industrial designers from two Danish regions. The findings demonstrate that the metal firm and designers, as producers, negotiate about materializing different logics into the bed throughout the innovation process. An aesthetic logic is prioritized most, and the producers encode it with the intention to develop a bed that looks homely and less hospital-like compared to previous and existing healthcare beds. After the bed is put into use, the aesthetic logic is decoded by the users. Their perception of it differs significantly from the producers’ intended meaning, as the healthcare bed is perceived as sterile. The study has theoretical implications: It demonstrates how logics become materialized ‘here and now’, and it reveals logics as less governed by stable and clear meanings but rather as subject to changeable perceptions.

Keywords: co-creation, healthcare innovation, commercialization, institutional logics

Procedia PDF Downloads 44
440 Numerical Study on Pretensioned Bridge Girder Using Thermal Strain Technique

Authors: Prashant Motwani, Arghadeep Laskar

Abstract:

The transfer of prestress force from prestressing strands to the surrounding concrete is dependent on the bond between the two materials. It is essential to understand the actual bond stress distribution along the transfer length to determine the transfer zone in pre-tensioned concrete. A 3-D nonlinear finite element model has been developed to simulate the transfer of prestress force from steel to concrete in pre-tensioned bridge girders through thermal strain technique using commercially available package ABAQUS. Full-scale bridge girder has been analyzed with thermal strain approach where the damage plasticity constitutive model has been used to model concrete. Parameters such as concrete strain, effective prestress, upward camber and longitudinal stress have been compared with analytical results. The discrepancy between numerical and analytical values was within 20%. The paper also presents a convergence study on mesh density and aspect ratio of the elements to perform the finite element study.

Keywords: aspect ratio, bridge girder, centre of gravity of strand, mesh density, finite element model, pretensioned bridge girder

Procedia PDF Downloads 200
439 Characterization of a Hypoeutectic Al Alloy Obtained by Selective Laser Melting

Authors: Jairo A. Muñoz, Alexander Komissarov, Alexander Gromov

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In this investigation, a hypoeutectic AlSi11Cu alloy was printed. This alloy was obtained in powder form with an average particle size of 40 µm. Bars 20 mm in diameter and 100 mm in length were printed with the building direction parallel to the bars' longitudinal direction. The microstructural characterization demonstrated an Al matrix surrounded by a Si network forming a coral-like pattern. The microstructure of the alloy showed a heterogeneous behavior with a mixture of columnar and equiaxed grains. Likewise, the texture indicated that the columnar grains were preferentially oriented towards the building direction, while the equiaxed followed a texture dominated by the cube component. On the other hand, the as-printed material strength showed higher values than those obtained in the same alloy using conventional processes such as casting. In addition, strength and ductility differences were found in the printed material, depending on the measurement direction. The highest values were obtained in the radial direction (565 MPa maximum strength and 4.8% elongation to failure). The lowest values corresponded to the transverse direction (508 MPa maximum strength and 3.2 elongation to failure), which corroborate the material anisotropy.

Keywords: additive manufacturing, aluminium alloy, melting pools, tensile test

Procedia PDF Downloads 131
438 Factors Influencing International Second Language Student's Perceptions of Academic Writing Practices

Authors: A. Shannaq

Abstract:

English is the accepted lingua franca of the academic world, and English medium higher education institutions host many second-language speakers of English (L2) who wish to pursue their studies through the medium of English. Assessment in higher education institutions is largely done in writing, which makes the mastery of academic writing essential. While such mastery can be, and often is, difficult for students who speak English as a first language, it is undoubtedly more so for L2 students attempting to adopt Anglophone academic written norms. There does not appear to be a great deal of research with regard to L2 students’ perceptions of their academic writing practices. This research investigates the writing practices of international L2 students in their first year of undergraduate study at NZ universities. Qualitative longitudinal data in the form of semi-structured interviews and documentation (assignments’ written instructions, students’ written assignments, tutors’ feedback on the students’ assignments) were collected from 4 undergraduate international L2 students at the beginning, middle, and end of the academic year 2017. Findings reveal that motivation, agency, and self-efficacy impact students’ perceptions of their academic writing practices and define the course of actions learners take under the time constraints which are set for their assignments.

Keywords: academic writing, English as a second language, international second language students, undergraduate writing practices

Procedia PDF Downloads 111
437 Acupuncture for Major Depressive Disorders: A Systematic Review of the Randomized Clinical Trials

Authors: Derick Shi-Chen Ou, Liang-Yu Chen

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Background: Acupuncture, a potential alternative, and complementary therapy revealed insufficient evidence in depression treatment. The efficacy of acupuncture treatment was still uncertainty. To evaluate the effect of acupuncture in treating depression, the randomized controlled trials (RCTs) were examined. Methods: RCTs of the acupuncture therapy in treating major depression were searched from MEDLINE from 2007 to 2017. Keywords used for searching strategy included acupuncture, acupoint, and major depressive disorder. Results: Among the nine RCTs, four studies demonstrated great improvement in acupuncture treatment and five studies revealed the effectiveness of acupuncture intervention in medication. General trends suggest that acupuncture treatment is as effective as antidepressants with minimal side effects. Conclusion: Despite the promising results from the RCTs, there are still a variety of limitations, including small sample size, imprecise enrollment criteria, difficulties with blinding, randomization, short duration of study and lack of longitudinal follow-up. Therefore, the evidence that acupuncture as an alternative therapy for depression is inconclusive. More rigorously designed RCTs should be conducted in the future.

Keywords: acupuncture, major depressive disorders, randomized clinical trials, antidepressants

Procedia PDF Downloads 217
436 Effects of School Culture and Curriculum on Gifted Adolescent Moral, Social, and Emotional Development: A Longitudinal Study of Urban Charter Gifted and Talented Programs

Authors: Rebekah Granger Ellis, Pat J. Austin, Marc P. Bonis, Richard B. Speaker, Jr.

Abstract:

Using two psychometric instruments, this study examined social and emotional intelligence and moral judgment levels of more than 300 gifted and talented high school students enrolled in arts-integrated, academic acceleration, and creative arts charter schools in an ethnically diverse large city in the southeastern United States. Gifted and talented individuals possess distinguishable characteristics; these frequently appear as strengths, but often serious problems accompany them. Although many gifted adolescents thrive in their environments, some struggle in their school and community due to emotional intensity, motivation and achievement issues, lack of peers and isolation, identification problems, sensitivity to expectations and feelings, perfectionism, and other difficulties. These gifted students endure and survive in school rather than flourish. Gifted adolescents face special intrapersonal, interpersonal, and environmental problems. Furthermore, they experience greater levels of stress, disaffection, and isolation than non-gifted individuals due to their advanced cognitive abilities. Therefore, it is important to examine the long-term effects of participation in various gifted and talented programs on the socio-affective development of these adolescents. Numerous studies have researched moral, social, and emotional development in the areas of cognitive-developmental, psychoanalytic, and behavioral learning; however, in almost all cases, these three facets have been studied separately leading to many divergent theories. Additionally, various frameworks and models purporting to encourage the different socio-affective branches of development have been debated in curriculum theory, yet research is inconclusive on the effectiveness of these programs. Most often studied is the socio-affective domain, which includes development and regulation of emotions; empathy development; interpersonal relations and social behaviors; personal and gender identity construction; and moral development, thinking, and judgment. Examining development in these domains can provide insight into why some gifted and talented adolescents are not always successful in adulthood despite advanced IQ scores. Particularly whether emotional, social and moral capabilities of gifted and talented individuals are as advanced as their intellectual abilities and how these are related to each other. This mixed methods longitudinal study examined students in urban gifted and talented charter schools for (1) socio-affective development levels and (2) whether a particular environment encourages developmental growth. Research questions guiding the study: (1) How do academically and artistically gifted 10th and 11th grade students perform on psychological scales of social and emotional intelligence and moral judgment? Do they differ from the normative sample? Do gender differences exist among gifted students? (2) Do adolescents who attend distinctive gifted charter schools differ in developmental profiles? Students’ performances on psychometric instruments were compared over time and by program type. Assessing moral judgment (DIT-2) and socio-emotional intelligence (BarOn EQ-I: YV), participants took pre-, mid-, and post-tests during one academic school year. Quantitative differences in growth on these psychological scales (individuals and school-wide) were examined. If a school showed change, qualitative artifacts (culture, curricula, instructional methodology, stakeholder interviews) provided insight for environmental correlation.

Keywords: gifted and talented programs, moral judgment, social and emotional intelligence, socio-affective education

Procedia PDF Downloads 161
435 Comparison of Growth and Biomass of Red Alga Cultured on Rope and Net

Authors: Esmaeil Kouhgardi, Saeedeh Dashti, Hakimeh Fekrandish

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This research has been conducted to study the method of culture and comparing growth and biomass of Gracilariacorticata cultured on rope and net for 50 days through two treatments (first treatment: culture of alga on net and the second treatment: culture of alga on rope and each treatment was repeated by four cases). During culture period, the water of aquariums was replaced once every two days for 40-50%. Also, 0.3-0.5 grams of Urea fertilizer was added to the culture environment for fertilization. Moreover, some of the environmental factors such as pH, salinity and temperature of the environment were measured on a daily basis. During the culture period, extent of longitudinal growth of the species of both treatments was equal. The said length was reached from 8-10 cm to 10.5-13 cm accordingly. The resulted weight in repetitions of the first treatment was higher than that of the second treatment in such a way as in the first treatment, its weight reached from 10 grams to 21.119 grams and in the second treatment, its weight reached from 10 grams to 17.663 grams. On a whole, it may be stated that that kind of alga being studied has a considerable growth with respect to its volume. The results have revealed that the percentage of daily growth and wet weight at the end of the first treatment was higher than that of the second treatment and it was registered as 0.934, 6.072 and 811.432 in the first treatment and 0.797, 4.990 and 758.071 in the second treatment respectively. This difference is significant (P < 0.05). Growth and biomass of G. corticata through culture on net was more emphasizing on numerous branches due to wider bed. Moreover, higher level of the species in this method was exposed to sunlight and this increased biosynthesis and eventually increases of growth and biomass.

Keywords: red alga, growth, biomass, culture, net, rope

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434 ELF in the Classroom: Use of ELF and Its Effects on Speaking Anxiety in Turkish Tertiary Level EFL Setting

Authors: Baki Dursun, Kemal Benk

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English as a Lingua Franca (ELF) has become an increasingly hot topic in many of the developing countries including Turkey. Likewise, in most of these expanding circle countries the way of teaching English has been redesigned in accordance with Lingua Franca Core. Admittedly, the focus was on Grammar-based teaching formerly; however, with the introduction of the ELF, the shift is now more on teaching speaking abilities and strategies of negotiation of meaning. However, there are several reasons for this shift, one of the major contributions stems from the teacher training programs offered by Turkish universities as M.A. programs. Therefore, the aim of this paper is to compare and contrast the similarities and divergences among the instructors who have taken ELF classes in their teacher-training program and those who have not. With a longitudinal design, for five months, classes of two different groups of teachers (ELF Group vs. Traditional Group) have been observed and three teachers have been selected for each group. During the observations, principles of Lingua Franca Core offered by Jenkins have been taken into account and used to form the rubric for the observations. After the five-month period, a Likert scale type questionnaire has been given to the students to explore their level of anxiety while speaking. Independent samples t-test have been administered to see the groups differences statistically. The results of the study will be presented during the conference.

Keywords: ELF, teacher training, speaking, anxiety

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433 Effect of the Birth Order and Arrival of Younger Siblings on the Development of a Child: Evidence from India

Authors: Swati Srivastava, Ashish Kumar Upadhyay

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Using longitudinal data from three waves of Young Lives Study and Ordinary Least Square methods, study has investigated the effect of birth order and arrival of younger siblings on child development in India. Study used child’s height for age z-score, weight for age z-score, BMI for age z-score, Peabody Picture Vocabulary Test (PPVT-Score)c, maths score, Early Grade Reading Assessment Test (ERGA) score, and memory score to measure the physical and cognitive development of child during wave-3. Findings suggest that having a high birth order is detrimental for child development and the gap between adjacent siblings is larger for children late in the birth sequences than early in the birth sequences. Study also reported that not only older siblings but arrival of younger siblings before assessment of test also reduces the development of a child. The effects become stronger in case of female children than male children.

Keywords: height for age z-score, weight for age z-score, BMI for z-score, PPVT score, math score, EGRA score, memory score, birth order, siblings, Young Lives Study, India

Procedia PDF Downloads 307
432 Effectiveness of Column Geometry in High-Rise Buildings

Authors: Man Singh Meena

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Structural engineers are facing different kind of challenges due to innovative & bold ideas of architects who are trying to design every structure with uniqueness. In RCC frame structures different geometry of columns can be used in design and rectangular columns can be placed with different type orientation. The analysis is design of structures can also be carried out by different type of software available i.e., STAAD Pro, ETABS and TEKLA. In recent times high-rise building modeling & analysis is done by ETABS due to its certain features which are superior to other software. The case study in this paper mainly emphasizes on structural behavior of high rise building for different column shape configurations like Circular, Square, Rectangular and Rectangular with 90-degree Rotation and rectangular shape plan. In all these column shapes the areas of columns are kept same to study the effect on design of concrete area is same. Modelling of 20-storeys R.C.C. framed building is done on the ETABS software for analysis. Post analysis of the structure, maximum bending moments, shear forces and maximum longitudinal reinforcement are computed and compared for three different story structures to identify the effectiveness of geometry of column.

Keywords: high-rise building, column geometry, building modelling, ETABS analysis, building design, structural analysis, structural optimization

Procedia PDF Downloads 41
431 Consumer Ethnocentrism: A Dynamic Literature Review from 1987-2015

Authors: Thi Phuong Chi Nguyen

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Although consumer ethnocentrism has been widely studied in academic research since 1987, somehow it is still considered as a new and unknown concept in marketing theory and practice. By analyzing the content, three mainstreams of consumer ethnocentrism were found including economic, management and marketing approaches. The present study indicated that the link between consumer ethnocentrism and consumer behaviours varies across countries. Consumers in developing countries might be both patriotic about their home countries and curious about foreign cultures at the same time. The most important finding is identifying three main periods in the chronological development of consumer ethnocentrism research. The first period, spanning from 1987 to 1995, was characterized by the introduction of the consumer ethnocentrism concepts and scales, the unidimensionality and the adaptation of the standard CETSCALE version. The second period 1996-2005 witnessed the replication of CETSCALE in various fields, as well as an increase in the volume of researches in developing and emerging countries; the exploration of determinants and the begin of multidimensionality. In the third period from 2006 to present, all variables related to CET were syntherized within the theory of planne behavior. Consumer ethnocentrism analyses were conducted even in less-developed countries and in groups of countries within longitudinal studies. The results from this study showed many inadequacies relating to consumer ethnocentrism in the context of globalisation for further researches to examine.

Keywords: CETSCALE, consumer behavior, consumer ethnocentrism, business, marketing

Procedia PDF Downloads 391
430 A quantitative Analysis of Impact of Potential Variables on the Energy Performance of Old and New Buildings in China

Authors: Yao Meng, Mahroo Eftekhari, Dennis Loveday

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Currently, there are two types of heating systems in Chinese residential buildings, with respect to the controllability of the heating system, one is an old heating system without any possibility of controlling room temperature and another is a new heating system that provides temperature control of individual rooms. This paper is aiming to evaluate the impact of potential variables on the energy performance of old and new buildings respectively in China, and to explore how the use of individual room temperature control would change occupants’ heating behaviour and thermal comfort in Chinese residential buildings and its impact on the building energy performance. In the study, two types of residential buildings have been chosen, the new building install personal control on the heating system, together with ‘pay for what you use’ tariffs. The old building comprised uncontrolled heating with payment based on floor area. The studies were carried out in each building, with a longitudinal monitoring of indoor air temperature, outdoor air temperature, window position. The occupants’ behaviour and thermal sensation were evaluated by questionnaires. Finally, use the simulated analytic method to identify the impact of influence variables on energy use for both types of buildings.

Keywords: residential buildings, China, design parameters, energy efficiency, simulation analytics method

Procedia PDF Downloads 527
429 Ambient Vibration Testing of Existing Buildings in Madinah

Authors: Tarek M. Alguhane, Ayman H. Khalil, M. N. Fayed, Ayman M. Ismail

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The elastic period has a primary role in the seismic assessment of buildings. Reliable calculations and/or estimates of the fundamental frequency of a building and its site are essential during analysis and design process. Various code formulas based on empirical data are generally used to estimate the fundamental frequency of a structure. For existing structures, in addition to code formulas and available analytical tools such as modal analyses, various methods of testing including ambient and forced vibration testing procedures may be used to determine dynamic characteristics. In this study, the dynamic properties of the 32 buildings located in the Madinah of Saudi Arabia were identified using ambient motions recorded at several, spatially-distributed locations within each building. Ambient vibration measurements of buildings have been analyzed and the fundamental longitudinal and transverse periods for all tested buildings are presented. The fundamental mode of vibration has been compared in plots with codes formulae (Saudi Building Code, EC8, and UBC1997). The results indicate that measured periods of existing buildings are shorter than that given by most empirical code formulas. Recommendations are given based on the common design and construction practice in Madinah city.

Keywords: ambient vibration, fundamental period, RC buildings, infill walls

Procedia PDF Downloads 241
428 Sales-Based Dynamic Investment and Leverage Decisions: A Longitudinal Study

Authors: Rihab Belguith, Fathi Abid

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The paper develops a system-based approach to investigate the dynamic adjustment of debt structure and investment policies of the Dow-Jones index. This approach enables the assessment of relations among sales, debt, and investment opportunities by considering the simultaneous effect of the market environmental change and future growth opportunities. We integrate the firm-specific sales variance to capture the industries' conditions in the model. Empirical results were obtained through a panel data set of firms with different sectors. The analysis support that environmental change does not affect equally the different industry since operating leverage differs among industries and so the sensitivity to sales variance. Including adjusted-specific variance, we find that there is no monotonic relation between leverage, sales, and investment. The firm may choose a low debt level in response to high sales variance but high leverage to attenuate the negative relation between sales variance and the current level of investment. We further find that while the overall effect of debt maturity on leverage is unaffected by the level of growth opportunities, the shorter the maturity of debt is, the smaller the direct effect of sales variance on investment.

Keywords: dynamic panel, investment, leverage decision, sales uncertainty

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427 [Keynote Speech]: Evidence-Based Outcome Effectiveness Longitudinal Study on Three Approaches to Reduce Proactive and Reactive Aggression in Schoolchildren: Group CBT, Moral Education, Bioneurological Intervention

Authors: Annis Lai Chu Fung

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While aggression had high stability throughout developmental stages and across generations, it should be the top priority of researchers and frontline helping professionals to develop prevention and intervention programme for aggressive children and children at risk of developing aggressive behaviours. Although there is a substantial amount of anti-bullying programmes, they gave disappointingly small effect sizes. The neglectful practical significance could be attributed to the overly simplistic categorisation of individuals involved as bullies or victims. In the past three decades, the distinction between reactive and proactive aggression has been well-proved. As children displaying reactively aggressive behaviours have distinct social-information processing pattern with those showing proactively aggressive behaviours, it is critical to identify the unique needs of the two subtypes accordingly when designing an intervention. The onset of reactive aggression and proactive aggression was observed at earliest in 4.4 and 6.8 years old respectively. Such findings called for a differential early intervention targeting these high-risk children. However, to the best of the author’s knowledge, the author was the first to establish an evidence-based intervention programme against reactive and proactive aggression. With the largest samples in the world, the author, in the past 10 years, explored three different approaches and their effectiveness against aggression quantitatively and qualitatively with longitudinal design. The three approaches presented are (a) cognitive-behavioral approach, (b) moral education, with Chinese marital arts and ethics as the medium, and (c) bioneurological measures (omega-3 supplementation). The studies adopted a multi-informant approach with repeated measures before and after the intervention, and follow-up assessment. Participants were recruited from primary and secondary schools in Hong Kong. In the cognitive-behavioral approach, 66 reactive aggressors and 63 proactive aggressors, aged from 11 to 17, were identified from 10,096 secondary-school children with questionnaire and subsequent structured interview. Participants underwent 10 group sessions specifically designed for each subtype of aggressor. Results revealed significant declines in aggression levels from the baseline to the follow-up assessment after 1 year. In moral education through the Chinese martial arts, 315 high-risk aggressive children, aged 6 to 12 years, were selected from 3,511 primary-school children and randomly assigned into four types of 10-session intervention group, namely martial-skills-only, martial-ethics-only, both martial-skills-and-ethics, and physical fitness (placebo). Results showed only the martial-skills-and-ethics group had a significant reduction in aggression after treatment and 6 months after treatment comparing with the placebo group. In the bioneurological approach, 218 children, aged from 8 to 17, were randomly assigned to the omega-3 supplement group and the placebo group. Results revealed that compared with the placebo group, the omega-3 supplement group had significant declines in aggression levels at the 6-month follow-up assessment. All three approaches were effective in reducing proactive and reactive aggression. Traditionally, intervention programmes against aggressive behaviour often adapted the cognitive and/or behavioural approach. However, cognitive-behavioural approach for children was recently challenged by its demanding requirement of cognitive ability. Traditional cognitive interventions may not be as beneficial to an older population as in young children. The present study offered an insightful perspective in aggression reduction measures.

Keywords: intervention, outcome effectiveness, proactive aggression, reactive aggression

Procedia PDF Downloads 202
426 Multivariate Assessment of Mathematics Test Scores of Students in Qatar

Authors: Ali Rashash Alzahrani, Elizabeth Stojanovski

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Data on various aspects of education are collected at the institutional and government level regularly. In Australia, for example, students at various levels of schooling undertake examinations in numeracy and literacy as part of NAPLAN testing, enabling longitudinal assessment of such data as well as comparisons between schools and states within Australia. Another source of educational data collected internationally is via the PISA study which collects data from several countries when students are approximately 15 years of age and enables comparisons in the performance of science, mathematics and English between countries as well as ranking of countries based on performance in these standardised tests. As well as student and school outcomes based on the tests taken as part of the PISA study, there is a wealth of other data collected in the study including parental demographics data and data related to teaching strategies used by educators. Overall, an abundance of educational data is available which has the potential to be used to help improve educational attainment and teaching of content in order to improve learning outcomes. A multivariate assessment of such data enables multiple variables to be considered simultaneously and will be used in the present study to help develop profiles of students based on performance in mathematics using data obtained from the PISA study.

Keywords: cluster analysis, education, mathematics, profiles

Procedia PDF Downloads 103
425 Self-Determination Theory at the Workplace: Associations between Need Satisfaction and Employment Outcomes

Authors: Wendy I. E. Wesseling

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The unemployment rate has been on the rise since the outbreak of the global financial crisis in 2008. Especially labor market entrants suffer from economic downfall. Despite the abundance of programs and agencies that help to reintegrate unemployed youth, considerable less research attention has been paid to 'fit' between these programs and its participants that ensure a durable labor market transition. According to Self-Determination Theory, need satisfaction is associated with better (mental) adjustment. As such, three hypothesis were formulated: when workers’ needs for competence (H1), relatedness (H2), and autonomy (H3) are satisfied in the workplace, they are more likely to remain employed at the same employer. To test these assumptions, a sample of approximately 800 young people enrolled in a youth unemployment policy participated in a longitudinal study. The unemployment policy was aimed at the development of generic and vocational competences, and had a maximum duration of six months. Need satisfaction during the program was measured, as well as their employment outcomes up to 12 months after completion of the policy. All hypotheses were (partly) supported. Some limitations should be noted. First, since our sample consisted primarily of highly educated white graduates, it remains to be tested whether our results generalize to other groups of unemployed youth. Moreover, we are unable to conclude whether the results are due to the intervention, participants (selection effect), or both, because of the lack of a control group.

Keywords: need satisfaction, person-job fit, self-determination theory, youth unemployment policy

Procedia PDF Downloads 237
424 Experimental and Analytical Study to Investigate the Effect of Tension Reinforcement on Behavior of Reinforced Concrete Short Beams

Authors: Hakan Ozturk, Aydin Demir, Kemal Edip, Marta Stojmanovska, Julijana Bojadjieva

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There are many factors that affect the behavior of reinforced concrete beams. These can be listed as concrete compressive and reinforcement yield strength, amount of tension, compression and confinement bars, and strain hardening of reinforcement. In the study, support condition of short beams is selected statically indeterminate to first degree. Experimental and numerical analysis are carried for reinforcement concrete (RC) short beams. Dimensions of cross sections are selected as 250mm width and 500 mm height. The length of RC short beams is designed as 2250 mm and these values are constant in all beams. After verifying accurately finite element model, a numerical parametric study is performed with varied diameter of tension reinforcement. Effect of change in diameter is investigated on behavior of RC short beams. As a result of the study, ductility ratios and failure modes are determined, and load-displacement graphs are obtained in order to understand the behavior of short beams. It is deduced that diameter of tension reinforcement plays very important role on the behavior of RC short beams in terms of ductility and brittleness.

Keywords: short beam, reinforced concrete, finite element analysis, longitudinal reinforcement

Procedia PDF Downloads 185
423 Predictors of Korean Women’s Attitudes toward Family Formation and the Intrahousehold Division of Labor

Authors: Damla Tas, Robert Rudolf

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Fast economic development and women empowerment in Korea have contributed to an unprecedented family and gender crisis, with Korean fertility rates at a global record low. This study explores the predictors and time trends of Korean women’s attitudes toward family formation and the household division of labor by using the Korean Longitudinal Survey of Women and Families from 2007 to 2018. Results indicate that education, age, marital status, and motherhood are significantly associated with women’s attitudes toward family formation and gender attitudes toward the intrahousehold division of labor. In addition, more educated women and those aged 26 to 45 are less likely to support traditional marriage and traditional household division of labor statements. Unmarried and divorced women are more likely to support progressive values and roles. Also, retrospective factors such as mothers’ schooling and parents’ relationship are significantly associated with gender role ideology. Our findings also indicate a downward trend in the number of Korean women stating one must have children. The study suggests that Korean families and society need to adjust to women’s changing preferences concerning their societal roles toward less traditional. Hence, a new agreement between men and women is needed on how work can be divided more equally.

Keywords: marriage, family formation, intrahousehold division of labor, gender role attitudes, Korea

Procedia PDF Downloads 49
422 Determination of the Optimum Size of Building Stone Blocks: Case Study of Delichai Travertine Mine

Authors: Hesam Sedaghat Nejad, Navid Hosseini, Arash Nikvar Hassani

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Determination of the optimum block size with high profitability is one of the significant parameters in designation of the building stone mines. The aim of this study was to determine the optimum dimensions of building stone blocks in Delichai travertine mine of Damavand in Tehran province through combining the effective parameters proven in determination of the optimum dimensions in building stones such as the spacing of joints and gaps, extraction tools constraints with the help of modeling by Gemcom software. To this end, following simulation of the topography of the mine, the block model was prepared and then in order to use spacing joints and discontinuities as a limiting factor, the existing joints set was added to the model. Since only one almost horizontal joint set with a slope of 5 degrees was available, this factor was effective only in determining the optimum height of the block, and thus to determine the longitudinal and transverse optimum dimensions of the extracted block, the power of available loader in the mine was considered as the secondary limiting factor. According to the aforementioned factors, the optimal block size in this mine was measured as 3.4×4×7 meter.

Keywords: building stone, optimum block size, Delichay travertine mine, loader power

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421 Using Fractal Architectures for Enhancing the Thermal-Fluid Transport

Authors: Surupa Shaw, Debjyoti Banerjee

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Enhancing heat transfer in compact volumes is a challenge when constrained by cost issues, especially those associated with requirements for minimizing pumping power consumption. This is particularly acute for electronic chip cooling applications. Technological advancements in microelectronics have led to development of chip architectures that involve increased power consumption. As a consequence packaging, technologies are saddled with needs for higher rates of power dissipation in smaller form factors. The increasing circuit density, higher heat flux values for dissipation and the significant decrease in the size of the electronic devices are posing thermal management challenges that need to be addressed with a better design of the cooling system. Maximizing surface area for heat exchanging surfaces (e.g., extended surfaces or “fins”) can enable dissipation of higher levels of heat flux. Fractal structures have been shown to maximize surface area in compact volumes. Self-replicating structures at multiple length scales are called “Fractals” (i.e., objects with fractional dimensions; unlike regular geometric objects, such as spheres or cubes whose volumes and surface area values scale as integer values of the length scale dimensions). Fractal structures are expected to provide an appropriate technology solution to meet these challenges for enhanced heat transfer in the microelectronic devices by maximizing surface area available for heat exchanging fluids within compact volumes. In this study, the effect of different fractal micro-channel architectures and flow structures on the enhancement of transport phenomena in heat exchangers is explored by parametric variation of fractal dimension. This study proposes a model that would enable cost-effective solutions for thermal-fluid transport for energy applications. The objective of this study is to ascertain the sensitivity of various parameters (such as heat flux and pressure gradient as well as pumping power) to variation in fractal dimension. The role of the fractal parameters will be instrumental in establishing the most effective design for the optimum cooling of microelectronic devices. This can help establish the requirement of minimal pumping power for enhancement of heat transfer during cooling. Results obtained in this study show that the proposed models for fractal architectures of microchannels significantly enhanced heat transfer due to augmentation of surface area in the branching networks of varying length-scales.

Keywords: fractals, microelectronics, constructal theory, heat transfer enhancement, pumping power enhancement

Procedia PDF Downloads 295
420 Ultrasonographic Evaluation of Tars and Metatars Region of Dromedary Camel

Authors: Aboozar Dehghan, S. Sharifi, A. Ardeshiri, F. Jafari, F. Samani

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Ultrasonography is a safe, particular, available and easy to use method to evaluate soft tissues. Tendons play the main role to body locomotors system. Ultrasonography performed in tarsus and metatarsus region of rare limb of eight adult, Dromedary camels (camelus dromedaries) in both sex. Clinical examination and gate analysis was performed before slaughtering. From the tarsus to the 1st phalanx was divided to 4 equal region include 1a, 2a, 1b and 2b. Flexor surface was clipped and covered by enough ultrasonography gel. Ultrasonography was performed by linear phased array 8-12 Mhz transducer in transverse and longitudinal section and Superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT) and suspensory ligament (SL) were imaged. Echogenicity and diameter of these structures were recorded. Size of tendons and SL measured after necropsy too. statistical analysis obtained that SDFT diameter larger than others in all described regions and mean of DDFT diameter larger than suspensory ligament. Echogenicity of SL more than SDFT and DDFT. No Significant relationship was seen between left and right rare limb structures size. Between sex and tendons and SL diameter, significant relationship not seen.

Keywords: dromedary camel, tars and metatars, ultrasonography

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419 Experimental Investigation on Residual Stresses in Welded Medium-Walled I-shaped Sections Fabricated from Q460GJ Structural Steel Plates

Authors: Qian Zhu, Shidong Nie, Bo Yang, Gang Xiong, Guoxin Dai

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GJ steel is a new type of high-performance structural steel which has been increasingly adopted in practical engineering. Q460GJ structural steel has a nominal yield strength of 460 MPa, which does not decrease significantly with the increase of steel plate thickness like normal structural steel. Thus, Q460GJ structural steel is normally used in medium-walled welded sections. However, research works on the residual stress in GJ steel members are few though it is one of the vital factors that can affect the member and structural behavior. This article aims to investigate the residual stresses in welded I-shaped sections fabricated from Q460GJ structural steel plates by experimental tests. A total of four full scale welded medium-walled I-shaped sections were tested by sectioning method. Both circular curve correction method and straightening measurement method were adopted in this study to obtain the final magnitude and distribution of the longitudinal residual stresses. In addition, this paper also explores the interaction between flanges and webs. And based on the statistical evaluation of the experimental data, a multilayer residual stress model is proposed.

Keywords: Q460GJ structural steel, residual stresses, sectioning method, welded medium-walled I-shaped sections

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418 Study on the Effect of Bolt Locking Method on the Deformation of Bipolar Plate in PEMFC

Authors: Tao Chen, ShiHua Liu, JiWei Zhang

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Assembly of the proton exchange membrane fuel cells (PEMFC) has a very important influence on its performance and efficiency. The various components of PEMFC stack are usually locked and fixed by bolts. Locking bolt will cause the deformation of the bipolar plate and the other components, which will affect directly the deformation degree of the integral parts of the PEMFC as well as the performance of PEMFC. This paper focuses on the object of three-cell stack of PEMFC. Finite element simulation is used to investigate the deformation of bipolar plate caused by quantity and layout of bolts, bolt locking pressure, and bolt locking sequence, etc. Finally, we made a conclusion that the optimal combination packaging scheme was adopted to assemble the fuel cell stack. The scheme was in use of 3.8 MPa locking pressure imposed on the fuel cell stack, type Ⅱ of four locking bolts and longitudinal locking method. The scheme was obtained by comparatively analyzing the overall displacement contour of PEMFC stack, absolute displacement curve of bipolar plate along the given three paths in the Z direction and the polarization curve of fuel cell. The research results are helpful for the fuel cell stack assembly.

Keywords: bipolar plate, deformation, finite element simulation, fuel cell, locking bolt

Procedia PDF Downloads 378
417 The Use of Boosted Multivariate Trees in Medical Decision-Making for Repeated Measurements

Authors: Ebru Turgal, Beyza Doganay Erdogan

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Machine learning aims to model the relationship between the response and features. Medical decision-making researchers would like to make decisions about patients’ course and treatment, by examining the repeated measurements over time. Boosting approach is now being used in machine learning area for these aims as an influential tool. The aim of this study is to show the usage of multivariate tree boosting in this field. The main reason for utilizing this approach in the field of decision-making is the ease solutions of complex relationships. To show how multivariate tree boosting method can be used to identify important features and feature-time interaction, we used the data, which was collected retrospectively from Ankara University Chest Diseases Department records. Dataset includes repeated PF ratio measurements. The follow-up time is planned for 120 hours. A set of different models is tested. In conclusion, main idea of classification with weighed combination of classifiers is a reliable method which was shown with simulations several times. Furthermore, time varying variables will be taken into consideration within this concept and it could be possible to make accurate decisions about regression and survival problems.

Keywords: boosted multivariate trees, longitudinal data, multivariate regression tree, panel data

Procedia PDF Downloads 176
416 A Comprehensive Review on the Effect of Corporal Punishment and Development of Defence Styles and Fear of Intimacy

Authors: Sandra Sasikumar, Noorjahan AI, Aurine Anthony

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The background of this article is the frequently unacknowledged effects of corporal punishment in a child's life as they change into adulthood, how it may permutate into various dynamics and combinations and manifest in major areas like fear of intimacy and reactive and ineffective defending styles, which may eventually lead to much more interpersonal problems and in extreme cases psychopathology. Even though such studies require a longitudinal research design, there is a wealth of information on corporal punishment in the literature. Defense styles, or the coping mechanisms that individuals use to deal with stress and difficult emotions, can also be affected by corporal punishment. Individuals who have experienced corporal punishment may develop maladaptive defense styles, such as repression or denial, that can make it difficult for them to process and cope with their emotions. The fear of intimacy, or the fear of getting close to others, is another potential effect of corporal punishment. Individuals who have experienced physical discipline may develop a fear of physical touch, making it difficult for them to form close relationships. This fear can also lead to other mental health issues, such as anxiety and depression. It is important to note that not everyone who experiences corporal punishment will develop these issues, and other factors can contribute to the development of these problems. However, corporal punishment can have a significant impact on an individual's mental and emotional well-being.

Keywords: corporal punishment, fear of intimacy, defense styles, attachment

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415 Successful Management of a Boy with Mild Persistent Asthma: A Longitudinal Case

Authors: A. Lubis, L. Setiawati, A. R. Setyoningrum, A. Suryawan, Irwanto

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Asthma is a condition that causing chronic health problems in children. In addition to basic therapy against disease, we must try to reduce the impact of chronic health problems and also optimize their medical aspect of growth and development. A boy with mild asthma attack frequent episode did not showed any improvement with medical treatment and his asthma control test was 11. From radiologic examination he got hyperaerated lung and billateral sinusitis maxillaris; skin test results were house dust, food and pet allergy; an overweight body; bad school grades; psychological and environmental problem. We followed and evaluated this boy in 6 months, treated holistically. Even we could not do much on environmental but no more psychological and school problems, his on a good bodyweight and his asthma control test was 22. A case of a child with mild asthma attack frequent episode was reported. Asthma clinical course show no significant improvement when other predisposing factor is not well-controlled and a child’s growth and development may be affected. Improving condition of the patient can be created with the help of loving and caring way of nurturing from the parents and supportive peer group. Therefore, continuous and consistent monitoring is required because prognosis of asthma is generally good when regularly and properly controlled.

Keywords: asthma, chronic health problems, growth, development

Procedia PDF Downloads 205