Search results for: behavior modelling
6574 A Comparative Study on Behavior Among Different Types of Shear Connectors using Finite Element Analysis
Authors: Mohd Tahseen Islam Talukder, Sheikh Adnan Enam, Latifa Akter Lithi, Soebur Rahman
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Composite structures have made significant advances in construction applications during the last few decades. Composite structures are composed of structural steel shapes and reinforced concrete combined with shear connectors, which benefit each material's unique properties. Significant research has been conducted on different types of connectors’ behavior and shear capacity. Moreover, the AISC 360-16 “Specification for Steel Structural Buildings” consists of a formula for channel shear connectors' shear capacity. This research compares the behavior of C type and L type shear connectors using Finite Element Analysis. Experimental results from published literature are used to validate the finite element models. The 3-D Finite Element Model (FEM) was built using ABAQUS 2017 to investigate non-linear capabilities and the ultimate load-carrying potential of the connectors using push-out tests. The changes in connector dimensions were analyzed using this non-linear model in parametric investigations. The parametric study shows that by increasing the length of the shear connector by 10 mm, its shear strength increases by 21%. Shear capacity increased by 13% as the height was increased by 10 mm. The thickness of the specimen was raised by 1 mm, resulting in a 2% increase in shear capacity. However, the shear capacity of channel connectors was reduced by 21% due to an increase of thickness by 2 mm.Keywords: finite element method, channel shear connector, angle shear connector, ABAQUS, composite structure, shear connector, parametric study, ultimate shear capacity, push-out test
Procedia PDF Downloads 1236573 A Bacterial Foraging Optimization Algorithm Applied to the Synthesis of Polyacrylamide Hydrogels
Authors: Florin Leon, Silvia Curteanu
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The Bacterial Foraging Optimization (BFO) algorithm is inspired by the behavior of bacteria such as Escherichia coli or Myxococcus xanthus when searching for food, more precisely the chemotaxis behavior. Bacteria perceive chemical gradients in the environment, such as nutrients, and also other individual bacteria, and move toward or in the opposite direction to those signals. The application example considered as a case study consists in establishing the dependency between the reaction yield of hydrogels based on polyacrylamide and the working conditions such as time, temperature, monomer, initiator, crosslinking agent and inclusion polymer concentrations, as well as type of the polymer added. This process is modeled with a neural network which is included in an optimization procedure based on BFO. An experimental study of BFO parameters is performed. The results show that the algorithm is quite robust and can obtain good results for diverse combinations of parameter values.Keywords: bacterial foraging, hydrogels, modeling and optimization, neural networks
Procedia PDF Downloads 1526572 Factors Affecting Expectations and Intentions of University Students’ Mobile Phone Use in Educational Contexts
Authors: Davut Disci
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Objective: to measure the factors affecting expectations and intentions of using mobile phone in educational contexts by university students, using advanced equations and modeling techniques. Design and Methodology: According to the literature, Mobile Addiction, Parental Surveillance- Safety/Security, Social Relations, and Mobile Behavior are most used terms of defining mobile use of people. Therefore these variables are tried to be measured to find and estimate their effects on expectations and intentions of using mobile phone in educational context. 421 university students participated in this study and there are 229 Female and 192 Male students. For the purpose of examining the mobile behavior and educational expectations and intentions, a questionnaire is prepared and applied to the participants who had to answer all the questions online. Furthermore, responses to close-ended questions are analyzed by using The Statistical Package for Social Sciences(SPSS) software, reliabilities are measured by Cronbach’s Alpha analysis and hypothesis are examined via using Multiple Regression and Linear Regression analysis and the model is tested with Structural Equation Modeling(SEM) technique which is important for testing the model scientifically. Besides these responses, open-ended questions are taken into consideration. Results: When analyzing data gathered from close-ended questions, it is found that Mobile Addiction, Parental Surveillance, Social Relations and Frequency of Using Mobile Phone Applications are affecting the mobile behavior of the participants in different levels, helping them to use mobile phone in educational context. Moreover, as for open-ended questions, participants stated that they use many mobile applications in their learning environment in terms of contacting with friends, watching educational videos, finding course material via internet. They also agree in that mobile phone brings greater flexibility to their lives. According to the SEM results the model is not evaluated and it can be said that it may be improved to show in SEM besides in multiple regression. Conclusion: This study shows that the specified model can be used by educationalist, school authorities to improve their learning environment.Keywords: education, mobile behavior, mobile learning, technology, Turkey
Procedia PDF Downloads 4216571 Schedule a New Production Plan by Heuristic Methods
Authors: Hanife Merve Öztürk, Sıdıka Dalgan
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In this project, a capacity analysis study is done at TAT A. Ş. Maret Plant. Production capacity of products which generate 80% of sales amount are determined. Obtained data entered the LEKIN Scheduling Program and we get production schedules by using heuristic methods. Besides heuristic methods, as mathematical model, disjunctive programming formulation is adapted to flexible job shop problems by adding a new constraint to find optimal schedule solution.Keywords: scheduling, flexible job shop problem, shifting bottleneck heuristic, mathematical modelling
Procedia PDF Downloads 4016570 Psychoeducation to Prevent Spread of HIV Among Men Who Have Sex with Men in Surabaya City
Authors: Christina Albertina Ludwinia Parung, I Gusti Ayu Maya Vratasti
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Sexual transmission of HIV among Men who have Sex with Men (MSM) is believed to be one of the sources of the AIDS epidemic. Nowadays, government, communities, and NGOs are taking action to prevent its spread by assisting and educating groups of MSM in their countries. This assistance involves experts in many fields of study, including psychology. In the field of psychology, psychoeducation is believed to be one of the ways to assist the MSM groups. Just like in other countries, this psychoeducation assistance is also needed in Indonesia, where MSM groups are found in many cities within. Surabaya, as the second largest and densely populated city in Indonesia, is known to have a big number of MSM population. In September to December 2020, the author and a colleague conducted a mentoring effort to the MSM community at the MSM community gathering location called Gang Pattaya, in the city of Surabaya. The existence of this community is disguised by the general public, but is well known by NGOs. Community members do MSM out of their liking, although some do it in exchange for money. However, safety factors, such as using condoms for MSM, are not a priority for this community. They do MSM whether they receive a reward or not, just out of a boost of pleasure. There is no attempt to find out the health of the partner once they are attracted to each other. In general, they do not know whether they are infected with HIV. Most of them feel healthy and since they do not show any symptoms, they think it is not necessary to get tested. In the mentoring process, the researchers conduct psychoeducation, which begins with an approach to certain individuals so that they are comfortable with the researchers’ presence, then increasing awareness of safe sex behavior for HIV prevention for groups in the form of counseling using the Theory of Reasoned Action (TRA) approach. Counseling is carried out in various forms including roleplay, games, and seminars. The number of participants was 11 people, varying from 19-47 years old. Pretest related to knowledge of safe sex was carried out before conducting the intervention and post-test after the intervention. The normality test used is the Shapiro-Wilk analysis. Different tests on the data obtained were carried out using the non-parametric Wilcoxon Signed Ranks Test. None of the participants had lower post-test knowledge scores than the pre-test. Prestest and post test for safer sex behavior showed 2 participants with safer sex behavior did not change. Both belong to the senior group, while other participants have an improvement in their safer sex behavior. These findings suggest that intervention programs for MSM as an effort to reduce HIV transmission should pay attention to affective and cognitive coping strategies.Keywords: HIV, men who have sex with men, psychoeducation, psychology health, safer sex behavior, theory of reasoned action
Procedia PDF Downloads 1396569 Pathologies in the Left Atrium Reproduced Using a Low-Order Synergistic Numerical Model of the Cardiovascular System
Authors: Nicholas Pearce, Eun-jin Kim
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Pathologies of the cardiovascular (CV) system remain a serious and deadly health problem for human society. Computational modelling provides a relatively accessible tool for diagnosis, treatment, and research into CV disorders. However, numerical models of the CV system have largely focused on the function of the ventricles, frequently overlooking the behaviour of the atria. Furthermore, in the study of the pressure-volume relationship of the heart, which is a key diagnosis of cardiac vascular pathologies, previous works often evoke popular yet questionable time-varying elastance (TVE) method that imposes the pressure-volume relationship instead of calculating it consistently. Despite the convenience of the TVE method, there have been various indications of its limitations and the need for checking its validity in different scenarios. A model of the combined left ventricle (LV) and left atrium (LA) is presented, which consistently considers various feedback mechanisms in the heart without having to use the TVE method. Specifically, a synergistic model of the left ventricle is extended and modified to include the function of the LA. The synergy of the original model is preserved by modelling the electro-mechanical and chemical functions of the micro-scale myofiber for the LA and integrating it with the microscale and macro-organ-scale heart dynamics of the left ventricle and CV circulation. The atrioventricular node function is included and forms the conduction pathway for electrical signals between the atria and ventricle. The model reproduces the essential features of LA behaviour, such as the two-phase pressure-volume relationship and the classic figure of eight pressure-volume loops. Using this model, disorders in the internal cardiac electrical signalling are investigated by recreating the mechano-electric feedback (MEF), which is impossible where the time-varying elastance method is used. The effects of AV node block and slow conduction are then investigated in the presence of an atrial arrhythmia. It is found that electrical disorders and arrhythmia in the LA degrade the CV system by reducing the cardiac output, power, and heart rate.Keywords: cardiovascular system, left atrium, numerical model, MEF
Procedia PDF Downloads 1156568 Hybrid Quasi-Steady Thermal Lattice Boltzmann Model for Studying the Behavior of Oil in Water Emulsions Used in Machining Tool Cooling and Lubrication
Authors: W. Hasan, H. Farhat, A. Alhilo, L. Tamimi
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Oil in water (O/W) emulsions are utilized extensively for cooling and lubricating cutting tools during parts machining. A robust Lattice Boltzmann (LBM) thermal-surfactants model, which provides a useful platform for exploring complex emulsions’ characteristics under variety of flow conditions, is used here for the study of the fluid behavior during conventional tools cooling. The transient thermal capabilities of the model are employed for simulating the effects of the flow conditions of O/W emulsions on the cooling of cutting tools. The model results show that the temperature outcome is slightly affected by reversing the direction of upper plate (workpiece). On the other hand, an important increase in effective viscosity is seen which supports better lubrication during the work.Keywords: hybrid lattice Boltzmann method, Gunstensen model, thermal, surfactant-covered droplet, Marangoni stress
Procedia PDF Downloads 3046567 Thermo-Aeraulic Studies of a Multizone Building Influence of the Compactness Index
Authors: S. M. A. Bekkouche, T. Benouaz, M. K. Cherier, M. Hamdani, M. R. Yaiche, N. Benamrane
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Most codes of building energy simulation neglect the humidity or well represent it with a very simplified method. It is for this reason that we have developed a new approach to the description and modeling of multizone buildings in Saharan climate. The thermal nodal method was used to apprehend thermoaeraulic behavior of air subjected to varied solicitations. In this contribution, analyzing the building geometry introduced the concept of index compactness as "quotient of external walls area and volume of the building". Physical phenomena that we have described in this paper, allow to build the model of the coupled thermoaeraulic behavior. The comparison shows that the found results are to some extent satisfactory. The result proves that temperature and specific humidity depending on compactness and geometric shape. Proper use of compactness index and building geometry parameters will noticeably minimize building energy.Keywords: multizone model, nodal method, compactness index, specific humidity, temperature
Procedia PDF Downloads 4106566 Unsupervised Sentiment Analysis for Indonesian Political Message on Twitter
Authors: Omar Abdillah, Mirna Adriani
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In this work, we perform new approach for analyzing public sentiment towards the presidential candidate in the 2014 Indonesian election that expressed in Twitter. In this study we propose such procedure for analyzing sentiment over Indonesian political message by understanding the behavior of Indonesian society in sending message on Twitter. We took different approach from previous works by utilizing punctuation mark and Indonesian sentiment lexicon that completed with the new procedure in determining sentiment towards the candidates. Our experiment shows the performance that yields up to 83.31% of average precision. In brief, this work makes two contributions: first, this work is the preliminary study of sentiment analysis in the domain of political message that has not been addressed yet before. Second, we propose such method to conduct sentiment analysis by creating decision making procedure in which it is in line with the characteristic of Indonesian message on Twitter.Keywords: unsupervised sentiment analysis, political message, lexicon based, user behavior understanding
Procedia PDF Downloads 4806565 Influence of Gender, Race, and Psychiatric Disorders on Sun Protective Behavior and Outcomes: A Population-Based Study
Authors: Holly D. Shan, Monique L. Bautista Neughebauer
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Sunscreen usage is emphasized in public health strategy as it reduces the risk of sunburns and skin cancers. This study aims to explore factors that influence sun protective behavior and outcomes. Data was received from the National Health Interview Survey (NHIS) 2020. Adults were asked how often they wore sunscreen when outside on a sunny day. Consistent use (“always”) of sunscreen, the incidence of sunburn within a year, and ever having a diagnosis of skin melanoma were compared by gender, race, and the diagnosis of anxiety, depression, and dementia. Individuals identifying as a mixed race were excluded. Statistical analysis was adjusted for large-scale surveys using STATA VSN 7.0, and a two-sided p<0.05 was considered significant. Of the 37,352 participants (53.18% females, 75.01% white, 10.49% black, 0.76% Indian Americans,5.60% Asian), 13.11% had a diagnosis of anxiety, 14.78% depression, and 0.84% dementia. Females wore sunscreen more often than males (24.72% vs. 10.91%, p<0.001). White individuals wore sunscreen most frequently; black individuals the least (17.37% vs. 6.49%, p<0.001). White individuals had the highest rate of sunburn (25.61%, p<0.001) and a history of skin melanoma (3.38%, p<0.001). Participants with anxiety, depression, and dementia all had statistically significantly decreased sunscreen use and increased frequency of sunburn compared to the general population. Only those with dementia had an increased incidence of skin melanoma (2.85% vs. 1.22%, p=0.009). Dermatologists and public health professionals should consider gender, race, and psychiatric comorbidities when counseling patients on sun protection.Keywords: sun protective behavior, psychiatric disorder, melanoma, sunburn
Procedia PDF Downloads 906564 Plastic Deformation of Mg-Gd Solid Solutions between 4K and 298K
Authors: Anna Kula, Raja K. Mishra, Marek Niewczas
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Deformation behavior of Mg-Gd solid solutions have been studied by a combination of measurements of mechanical response, texture and dislocation substructure. Increase in Gd content strongly influences the work-hardening behavior and flow characteristics in tension and compression. Adiabatic instabilities have been observed in all alloys at 4K under both tension and compression. The frequency and the amplitude of adiabatic stress oscillations increase with Gd content. Profuse mechanical twinning has been observed under compression, resulting in a texture dominated by basal component parallel to the compression axis. Under tension, twining is less active and the texture evolution is affected mostly by slip. Increasing Gd concentration leads to the reduction of the tension and compression asymmetry due to weakening of the texture and stabilizing more homogenous twinning and slip, involving basal and non-basal slip systems.Keywords: Mg-Gd alloys, mechanical properties, work hardening, twinning
Procedia PDF Downloads 5396563 The Influence of Immunity on the Behavior and Dignity of Judges
Authors: D. Avnieli
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Immunity of judges from liability represents a departure from the principle that all are equal under the law, and that victims may be granted compensation from their offenders. The purpose of the study is to determine if judicial immunity coincides with the need to ensure the existence of highly independent and incorruptible judiciary. Judges are immune from civil and criminal liability for their judicial acts. Judicial immunity is justified by the need to maintain complete independence and discretion of the judiciary. Scholars and judges believe that absolute immunity is needed to shield judges from pressures, threats, or outside interference. It is commonly accepted, that judges should be free to perform their judicial role in accordance with their assessment of the fact and their understanding of the law, without any restrictions, influences, inducements or interferences. In most countries, immunity applies when judges act in excess of jurisdiction. In some countries, it applies even when they act maliciously or corruptly. The only exception to absolute immunity applicable in all judicial systems is when judges act without jurisdiction over the subject matter. The Israeli Supreme Court recently decided to embrace absolute immunity and strike off a lawsuit of a refugee, who was unlawfully incarcerated. The Court ruled that the plaintiff cannot sue the State or the judge for damages. The questions of malice, dignity, and public scrutiny were not discussed. This paper, based on comparative analysis of many cases, aims to determine if immunity affects the dignity and behavior of judges. It demonstrates that most judges maintain their dignity and ethical code of behavior, but sometimes do not hesitate to act consciously in excess of jurisdiction, and in rare cases even corruptly. Therefore, in order to maintain independent and incorruptible judiciary, immunity should not be applied where judges act consciously in excess of jurisdiction or with malicious incentives.Keywords: incorruptible judiciary, immunity, independent, judicial, judges, jurisdiction
Procedia PDF Downloads 1036562 Microstructure of AlCrFeNiMn High Entropy Alloy and Its Corrosion Behavior in Supercritical CO₂ Environment
Authors: Yang Wanhuan, Zou Jichun, LI Shen, Zhong Weihua, Yang Wen
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High entropy alloys (HEAs) have aroused significant concern in high-temperature supercritical carbon dioxide (S-CO2) environments due to their unique microstructures and outstanding properties. However, the anti-corrosion ability and mechanism of these HEAs in the S-CO₂ remain unclear. Herein, we developed a new AlCrFeNiMn (AM)-HEA with double phases by vacuum arc melting furnace. The corrosion behavior of AM-HEA in the S-CO₂ at 500 ℃ under 25 MPa for 400 hours was deciphered by multiple characterization techniques. The results show that the discrepancy of corrosion between the matrix and boundary was accounted for by their microstructure and components. The role and mechanism of Mn contents for their oxide scales in boundary zones were emphasized. More importantly, the nano-precipitated second phase and numerous boundaries for the outstanding anti-corrosion ability of the matrix were proposed.Keywords: high entropy alloy, microstructure, corrosion, supercritical carbon oxide, AlCrFeNiMn
Procedia PDF Downloads 1466561 Theoretical Modal Analysis of Freely and Simply Supported RC Slabs
Authors: M. S. Ahmed, F. A. Mohammad
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This paper focuses on the dynamic behavior of reinforced concrete (RC) slabs. Therefore, the theoretical modal analysis was performed using two different types of boundary conditions. Modal analysis method is the most important dynamic analyses. The analysis would be modal case when there is no external force on the structure. By using this method in this paper, the effects of freely and simply supported boundary conditions on the frequencies and mode shapes of RC square slabs are studied. ANSYS software was employed to derive the finite element model to determine the natural frequencies and mode shapes of the slabs. Then, the obtained results through numerical analysis (finite element analysis) would be compared with an exact solution. The main goal of the research study is to predict how the boundary conditions change the behavior of the slab structures prior to performing experimental modal analysis. Based on the results, it is concluded that simply support boundary condition has obvious influence to increase the natural frequencies and change the shape of mode when it is compared with freely supported boundary condition of slabs. This means that such support conditions have direct influence on the dynamic behavior of the slabs. Thus, it is suggested to use free-free boundary condition in experimental modal analysis to precisely reflect the properties of the structure. By using free-free boundary conditions, the influence of poorly defined supports is interrupted.Keywords: natural frequencies, mode shapes, modal analysis, ANSYS software, RC slabs
Procedia PDF Downloads 4576560 Learning Participation and Baby Care Ability in Mothers of Preterm Infant
Authors: Yi-Chuan Cheng, Li-Chi Huang, Yu-Shan Chang
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Introduction: The main purpose of this study was to explore the relationship between the learning number, care knowledge, care skills and maternal confidence in preterm infant care in Taiwan. Background: Preterm infants care has been stressful for mother caring at home. Many programs have been applied for improving the infant care maternal confident. But less to know the learning behavior in mothers of preterm infant. Methods: The sample consisted of 55 mothers with preterm infants were recruited in a neonatal intermediate unit at a medical center in central Taiwan. The self-reported questionnaires including knowledge and skills of preterm infant care scales and maternal confidence scale were used to evaluation, which were conducted during hospitalization, before hospital discharge, and one month after discharge. We performed by using Pearson correlation of the collected data using SPSS 18. Results: The study showed that the learning number and knowledge in preterm infant care was a significant positive correlation (r = .40), and the skills and confidence preterm infant care was positively correlated (r = .89). Conclusions: Study results showed the mother had more learning number in preterm infant care will be stronger knowledge, and the skills and confidence in preterm infant care were also positively correlated. Thus, we found the learning behavior change significant care knowledge. And the maternal confidence change significant with skill on preterm infant’s care. But bondage still needs further study and develop the participation in hospital-based instructional programs, which could lead to greater long-term retention of learning.Keywords: learning behavior, care knowledge, care skills, maternal confidence
Procedia PDF Downloads 2606559 Impact of Artificial Intelligence Technologies on Information-Seeking Behaviors and the Need for a New Information Seeking Model
Authors: Mohammed Nasser Al-Suqri
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Former information-seeking models are proposed more than two decades ago. These already existed models were given prior to the evolution of digital information era and Artificial Intelligence (AI) technologies. Lack of current information seeking models within Library and Information Studies resulted in fewer advancements for teaching students about information-seeking behaviors, design of library tools and services. In order to better facilitate the aforementioned concerns, this study aims to propose state-of-the-art model while focusing on the information seeking behavior of library users in the Sultanate of Oman. This study aims for the development, designing and contextualizing the real-time user-centric information seeking model capable of enhancing information needs and information usage along with incorporating critical insights for the digital library practices. Another aim is to establish far-sighted and state-of-the-art frame of reference covering Artificial Intelligence (AI) while synthesizing digital resources and information for optimizing information-seeking behavior. The proposed study is empirically designed based on a mix-method process flow, technical surveys, in-depth interviews, focus groups evaluations and stakeholder investigations. The study data pool is consist of users and specialist LIS staff at 4 public libraries and 26 academic libraries in Oman. The designed research model is expected to facilitate LIS by assisting multi-dimensional insights with AI integration for redefining the information-seeking process, and developing a technology rich model.Keywords: artificial intelligence, information seeking, information behavior, information seeking models, libraries, Sultanate of Oman
Procedia PDF Downloads 1156558 Application of Double Side Approach Method on Super Elliptical Winkler Plate
Authors: Hsiang-Wen Tang, Cheng-Ying Lo
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In this study, the static behavior of super elliptical Winkler plate is analyzed by applying the double side approach method. The lack of information about super elliptical Winkler plates is the motivation of this study and we use the double side approach method to solve this problem because of its superior ability on efficiently treating problems with complex boundary shape. The double side approach method has the advantages of high accuracy, easy calculation procedure and less calculation load required. Most important of all, it can give the error bound of the approximate solution. The numerical results not only show that the double side approach method works well on this problem but also provide us the knowledge of static behavior of super elliptical Winkler plate in practical use.Keywords: super elliptical winkler plate, double side approach method, error bound, mechanic
Procedia PDF Downloads 3566557 The Dietary Behavior of Eating Alone in Middle-Aged Populations by Body Mass Index (BMI)
Authors: Pil Kyoo Jo, Youngmee Lee, Jee Young Kim, Yu Jin Oh, Sohyun Park, Young Ha Joo, Hye Suk Kim, Semi Kang
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A growing number of people are living alone and eating alone. People might have different dietary behaviors between eating alone and eating with others, it can influence their weight and health. The purpose of this study was to investigate the dietary behavior of eating alone in middle-aged populations in South Korea. We used the nationally representative data from the 5th Korea National Health and Nutrition Examination Survey (KNHANES), 2010-2012 and a cross-sectional survey on the eating behaviors among adults (N=1318, 530 men, 788 women) aged from 20 to 54 years. Results showed that ‘underweight’ group ate more amount of food when eating with others compared to eating alone and ‘overweight’ and ‘obesity’ groups had opposite respondent (p<0.05). When having a meal alone, ‘underweight’ group ate food until didn’t feel hungry and ‘overweight’ and ‘obesity’ groups ate leftover food even they felt full (p<0.01). The ‘overweight’ and ‘obesity’ groups usually ate alone than ‘underweight’ group did (p<0.05). All groups had faster meal time when eating alone than eating with others and usually ate processed foods for convenience when eating alone. Younger people, aged 10-30, ate more processed food than older people did. South Koreans spend nearly 45% of their total food consumption from processed foods. This research was supported by the National Research Foundation of Korea for 2011 Korea-Japan Basic Scientific Cooperation Program (NRF-2011B00003). This work was supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea (NRF-2015S1A5B6037369).Keywords: BMI, dietary behavior, eating alone, middle-aged populations
Procedia PDF Downloads 2706556 A Method to Predict the Thermo-Elastic Behavior of Laser-Integrated Machine Tools
Authors: C. Brecher, M. Fey, F. Du Bois-Reymond, S. Neus
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Additive manufacturing has emerged into a fast-growing section within the manufacturing technologies. Established machine tool manufacturers, such as DMG MORI, recently presented machine tools combining milling and laser welding. By this, machine tools can realize a higher degree of flexibility and a shorter production time. Still there are challenges that have to be accounted for in terms of maintaining the necessary machining accuracy - especially due to thermal effects arising through the use of high power laser processing units. To study the thermal behavior of laser-integrated machine tools, it is essential to analyze and simulate the thermal behavior of machine components, individual and assembled. This information will help to design a geometrically stable machine tool under the influence of high power laser processes. This paper presents an approach to decrease the loss of machining precision due to thermal impacts. Real effects of laser machining processes are considered and thus enable an optimized design of the machine tool, respective its components, in the early design phase. Core element of this approach is a matched FEM model considering all relevant variables arising, e.g. laser power, angle of laser beam, reflective coefficients and heat transfer coefficient. Hence, a systematic approach to obtain this matched FEM model is essential. Indicating the thermal behavior of structural components as well as predicting the laser beam path, to determine the relevant beam intensity on the structural components, there are the two constituent aspects of the method. To match the model both aspects of the method have to be combined and verified empirically. In this context, an essential machine component of a five axis machine tool, the turn-swivel table, serves as the demonstration object for the verification process. Therefore, a turn-swivel table test bench as well as an experimental set-up to measure the beam propagation were developed and are described in the paper. In addition to the empirical investigation, a simulative approach of the described types of experimental examination is presented. Concluding, it is shown that the method and a good understanding of the two core aspects, the thermo-elastic machine behavior and the laser beam path, as well as their combination helps designers to minimize the loss of precision in the early stages of the design phase.Keywords: additive manufacturing, laser beam machining, machine tool, thermal effects
Procedia PDF Downloads 2656555 Asset Liability Modelling for Pension Funds by Introducing Leslie Model for Population Dynamics
Authors: Kristina Sutiene, Lina Dapkute
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The paper investigates the current demographic trends that exert the sustainability of pension systems in most EU regions. Several drivers usually compose the demographic challenge, coming from the structure and trends of population in the country. As the case of research, three main variables of demographic risk in Lithuania have been singled out and have been used in making up the analysis. Over the last two decades, the country has presented a peculiar demographic situation characterized by pessimistic fertility trends, negative net migration rate and rising life expectancy that make the significant changes in labor-age population. This study, therefore, sets out to assess the relative impact of these risk factors both individually and in aggregate, while assuming economic trends to evolve historically. The evidence is presented using data of pension funds that operate in Lithuania and are financed by defined-contribution plans. To achieve this goal, the discrete-time pension fund’s value model is developed that reflects main operational modalities: contribution income from current participants and new entrants, pension disbursement and administrative expenses; it also fluctuates based on returns from investment activity. Age-structured Leslie population dynamics model has been integrated into the main model to describe the dynamics of fertility, migration and mortality rates upon age. Validation has concluded that Leslie model adequately fits the current population trends in Lithuania. The elasticity of pension system is examined using Loimaranta efficiency as a measure for comparison of plausible long-term developments of demographic risks. With respect to the research question, it was found that demographic risks have different levels of influence on future value of aggregated pension funds: The fertility rates have the highest importance, while mortality rates give only a minor impact. Further studies regarding the role of trying out different economic scenarios in the integrated model would be worthwhile.Keywords: asset liability modelling, Leslie model, pension funds, population dynamics
Procedia PDF Downloads 2696554 Simulation of Welded Steel Tube Subjected to Internal Pressure
Authors: H. Zedira, M. T. Hannachi, H. Djebaili, B. Daheche
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The rapid pace of technology development and strong competition in the market, prompted us to consider the field of manufacturing of steel pipes by a process complies fully with the requirements of industrial induction welding is high frequency (HF), this technique is better known today in Algeria, more precisely for the manufacture of tubes diameters Single Annabib TG Tebessa. The aim of our study is based on the characterization of processes controlling the mechanical behavior of steel pipes (type E24-2), welded by high frequency induction, considering the different tests and among the most destructive known test internal pressure. The internal pressure test is performed according to the application area of welded pipes, or as leak test, either as a test of strength (bursting). All tubes are subjected to a hydraulic test pressure of 50 bar kept at room temperature for a period of 6 seconds. This study provides information that helps optimize the design and implementation to predict the behavior of the tubes during operation.Keywords: castem, pressure, stress, tubes, thickness
Procedia PDF Downloads 3266553 Measurement and Modelling of HIV Epidemic among High Risk Groups and Migrants in Two Districts of Maharashtra, India: An Application of Forecasting Software-Spectrum
Authors: Sukhvinder Kaur, Ashok Agarwal
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Background: For the first time in 2009, India was able to generate estimates of HIV incidence (the number of new HIV infections per year). Analysis of epidemic projections helped in revealing that the number of new annual HIV infections in India had declined by more than 50% during the last decade (GOI Ministry of Health and Family Welfare, 2010). Then, National AIDS Control Organisation (NACO) planned to scale up its efforts in generating projections through epidemiological analysis and modelling by taking recent available sources of evidence such as HIV Sentinel Surveillance (HSS), India Census data and other critical data sets. Recently, NACO generated current round of HIV estimates-2012 through globally recommended tool “Spectrum Software” and came out with the estimates for adult HIV prevalence, annual new infections, number of people living with HIV, AIDS-related deaths and treatment needs. State level prevalence and incidence projections produced were used to project consequences of the epidemic in spectrum. In presence of HIV estimates generated at state level in India by NACO, USIAD funded PIPPSE project under the leadership of NACO undertook the estimations and projections to district level using same Spectrum software. In 2011, adult HIV prevalence in one of the high prevalent States, Maharashtra was 0.42% ahead of the national average of 0.27%. Considering the heterogeneity of HIV epidemic between districts, two districts of Maharashtra – Thane and Mumbai were selected to estimate and project the number of People-Living-with-HIV/AIDS (PLHIV), HIV-prevalence among adults and annual new HIV infections till 2017. Methodology: Inputs in spectrum included demographic data from Census of India since 1980 and sample registration system, programmatic data on ‘Alive and on ART (adult and children)’,‘Mother-Baby pairs under PPTCT’ and ‘High Risk Group (HRG)-size mapping estimates’, surveillance data from various rounds of HSS, National Family Health Survey–III, Integrated Biological and Behavioural Assessment and Behavioural Sentinel Surveillance. Major Findings: Assuming current programmatic interventions in these districts, an estimated decrease of 12% points in Thane and 31% points in Mumbai among new infections in HRGs and migrants is observed from 2011 by 2017. Conclusions: Project also validated decrease in HIV new infection among one of the high risk groups-FSWs using program cohort data since 2012 to 2016. Though there is a decrease in HIV prevalence and new infections in Thane and Mumbai, further decrease is possible if appropriate programme response, strategies and interventions are envisaged for specific target groups based on this evidence. Moreover, evidence need to be validated by other estimation/modelling techniques; and evidence can be generated for other districts of the state, where HIV prevalence is high and reliable data sources are available, to understand the epidemic within the local context.Keywords: HIV sentinel surveillance, high risk groups, projections, new infections
Procedia PDF Downloads 2116552 Bending Behaviour of Fiber Reinforced Polymer Composite Stiffened Panel Subjected to Transverse Loading
Authors: S. Kumar, Rajesh Kumar, S. Mandal
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Fiber Reinforced Polymer (FRP) is gaining popularity in many branch of engineering and various applications due to their light weight, specific strength per unit weight and high stiffness in particular direction. As the strength of material is high it can be used in thin walled structure as industrial roof sheds satisfying the strength constraint with comparatively lesser thickness. Analysis of bending behavior of FRP panel has been done here with variation in oriented angle of stiffener panels, fiber orientation, aspect ratio and boundary conditions subjected to transverse loading by using Finite Element Method. The effect of fiber orientation and thickness of ply has also been studied to determine the minimum thickness of ply for optimized section of stiffened FRP panel.Keywords: bending behavior, fiber reinforced polymer, finite element method, orientation of stiffeners
Procedia PDF Downloads 3926551 Effect of Toxic Metals Exposure on Rat Behavior and Brain Morphology: Arsenic, Manganese
Authors: Tamar Bikashvili, Tamar Lordkipanidze, Ilia Lazrishvili
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Heavy metals remain one of serious environmental problems due to their toxic effects. The effect of arsenic and manganese compounds on rat behavior and neuromorphology was studied. Wistar rats were assigned to four groups: rats in control group were given regular water, while rats in other groups drank water with final manganese concentration of 10 mg/L (group A), 20 mg/L (group B) and final arsenic concentration 68 mg/L (group C), respectively, for a month. To study exploratory and anxiety behavior and also to evaluate aggressive performance in “home cage” rats were tested in “Open Field” and to estimate learning and memory status multi-branched maze was used. Statistically significant increase of motor and oriental-searching activity in experimental groups was revealed by an open field test, which was expressed in increase of number of lines crossed, rearing and hole reflexes. Obtained results indicated the suppression of fear in rats exposed to manganese. Specifically, this was estimated by the frequency of getting to the central part of the open field. Experiments revealed that 30-day exposure to 10 mg/ml manganese did not stimulate aggressive behavior in rats, while exposure to the higher dose (20 mg/ml), 37% of initially non-aggressive animals manifested aggressive behavior. Furthermore, 25% of rats were extremely aggressive. Obtained data support the hypothesis that excess manganese in the body is one of the immediate causes of enhancement of interspecific predatory aggressive and violent behavior in rats. It was also discovered that manganese intoxication produces non-reversible severe learning disability and insignificant, reversible memory disturbances. Studies of rodents exposed to arsenic also revealed changes in the learning process. As it is known, the distribution of metal ions differs in various brain regions. The principle manganese accumulation was observed in the hippocampus and in the neocortex, while arsenic was predominantly accumulated in nucleus accumbens, striatum, and cortex. These brain regions play an important role in the regulation of emotional state and motor activity. Histopathological analyzes of brain sections illustrated two morphologically distinct altered phenotypes of neurons: (1) shrunk cells with indications of apoptosis - nucleus and cytoplasm were very difficult to be distinguished, the integrity of neuronal cytoplasm was not disturbed; and (2) swollen cells - with indications of necrosis. Pyknotic nucleus, plasma membrane disruption and cytoplasmic vacuoles were observed in swollen neurons and they were surrounded by activated gliocytes. It’s worth to mention that in the cortex the majority of damaged neurons were apoptotic while in subcortical nuclei –neurons were mainly necrotic. Ultrastructural analyses demonstrated that all cell types in the cortex and the nucleus caudatus represent destructed mitochondria, widened neurons’ vacuolar system profiles, increased number of lysosomes and degeneration of axonal endings.Keywords: arsenic, manganese, behavior, learning, neuron
Procedia PDF Downloads 3596550 Business Ethics in Islam: Making Islamic Banking Attractive for the Customers Round the Globe
Authors: Fahad Ahmed Qureshi
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Is it essential for a Muslim businessperson and employees of Islamic financial institutions not only in Islamic Banks to perform his/her actions ethically in a universally, competing habitat? The answer is an emphatic NO! in Islam, ethics conduct all departments of life. The orders for eternal success or falah in Islam are the same for all Muslims–whether in managing their business activities or in carrying out their routine affairs. Without designating any circumstantial ambience, Allah specify people who achieve success as those who are “inviting to all that is good (Khayr), enjoining what is right (Ma'ruf) and forbidding what is wrong (Munkar).” Within a business context, however, what sole axioms of regimen should a company follow? What is a Muslim businessperson’s encumbrance to internal and external stakeholders? Although an organization’s top executives may display sterling ethical behavior, how can middle- and lower-level managers be enthusiastic to perform in a correspondingly ethical manner? What are some protocols that would clinch persistent ethical behavior in a Muslim business?Keywords: business, ethics, finance, Islam
Procedia PDF Downloads 4036549 Computational Modelling of Epoxy-Graphene Composite Adhesive towards the Development of Cryosorption Pump
Authors: Ravi Verma
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Cryosorption pump is the best solution to achieve clean, vibration free ultra-high vacuum. Furthermore, the operation of cryosorption pump is free from the influence of electric and magnetic fields. Due to these attributes, this pump is used in the space simulation chamber to create the ultra-high vacuum. The cryosorption pump comprises of three parts (a) panel which is cooled with the help of cryogen or cryocooler, (b) an adsorbent which is used to adsorb the gas molecules, (c) an epoxy which holds the adsorbent and the panel together thereby aiding in heat transfer from adsorbent to the panel. The performance of cryosorption pump depends on the temperature of the adsorbent and hence, on the thermal conductivity of the epoxy. Therefore we have made an attempt to increase the thermal conductivity of epoxy adhesive by mixing nano-sized graphene filler particles. The thermal conductivity of epoxy-graphene composite adhesive is measured with the help of indigenously developed experimental setup in the temperature range from 4.5 K to 7 K, which is generally the operating temperature range of cryosorption pump for efficiently pumping of hydrogen and helium gas. In this article, we have presented the experimental results of epoxy-graphene composite adhesive in the temperature range from 4.5 K to 7 K. We have also proposed an analytical heat conduction model to find the thermal conductivity of the composite. In this case, the filler particles, such as graphene, are randomly distributed in a base matrix of epoxy. The developed model considers the complete spatial random distribution of filler particles and this distribution is explained by Binomial distribution. The results obtained by the model have been compared with the experimental results as well as with the other established models. The developed model is able to predict the thermal conductivity in both isotropic regions as well as in anisotropic region over the required temperature range from 4.5 K to 7 K. Due to the non-empirical nature of the proposed model, it will be useful for the prediction of other properties of composite materials involving the filler in a base matrix. The present studies will aid in the understanding of low temperature heat transfer which in turn will be useful towards the development of high performance cryosorption pump.Keywords: composite adhesive, computational modelling, cryosorption pump, thermal conductivity
Procedia PDF Downloads 896548 Solving the Set Covering Problem Using the Binary Cat Swarm Optimization Metaheuristic
Authors: Broderick Crawford, Ricardo Soto, Natalia Berrios, Eduardo Olguin
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In this paper, we present a binary cat swarm optimization for solving the Set covering problem. The set covering problem is a well-known NP-hard problem with many practical applications, including those involving scheduling, production planning and location problems. Binary cat swarm optimization is a recent swarm metaheuristic technique based on the behavior of discrete cats. Domestic cats show the ability to hunt and are curious about moving objects. The cats have two modes of behavior: seeking mode and tracing mode. We illustrate this approach with 65 instances of the problem from the OR-Library. Moreover, we solve this problem with 40 new binarization techniques and we select the technical with the best results obtained. Finally, we make a comparison between results obtained in previous studies and the new binarization technique, that is, with roulette wheel as transfer function and V3 as discretization technique.Keywords: binary cat swarm optimization, binarization methods, metaheuristic, set covering problem
Procedia PDF Downloads 3966547 Punching Shear Behavior of RC Column Footing on Stabilized Ground
Authors: Sukanta K. Shill, Md. M. Hoque, Md. Shaifullah
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An experiment on the punching of RC column footing, comparison of test result to established different codes for punching shear calculation of column footings is presented in the paper. The principal aim of this study is to investigate the punching shear behavior of an isolated column footing using brick aggregate as coarse aggregate. Consequence, a RC model footing was constructed on a stabilized soil and tested the footing under field condition. The test result yields that the experimental punching shear capacity is greater than all the theoretical punching shear capacities obtained by using different codes of practices. It can be stated that BNBC 1993, as well as ACI 318, 2002 code formulae are very conservative in predicting the punching shear resistance of RC footing, whereas the CEB-FIP MC, 1990 formula and Eurocode2 formula are less conservative in predicting the punching shear resistance of footing.Keywords: footing, punching shear, field condition, stabilized soil, brick aggregate
Procedia PDF Downloads 4096546 Study of the Polymer Elastic Behavior in the Displacement Oil Drops at Pore Scale
Authors: Luis Prada, Jose Gomez, Arlex Chaves, Julio Pedraza
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Polymeric liquids have been used in the oil industry, especially at enhanced oil recovery (EOR). From the rheological point of view, polymers have the particularity of being viscoelastic liquids. One of the most common and useful models to describe that behavior is the Upper Convected Maxwell model (UCM). The main characteristic of the polymer used in EOR process is the increase in viscosity which pushes the oil outside of the reservoir. The elasticity could contribute in the drag of the oil that stays in the reservoir. Studying the elastic effect on the oil drop at the pore scale, bring an explanation if the addition of elastic force could mobilize the oil. This research explores if the contraction and expansion of the polymer in the pore scale may increase the elastic behavior of this kind of fluid. For that reason, this work simplified the pore geometry and build two simple geometries with micrometer lengths. Using source terms with the user define a function this work introduces the UCM model in the ANSYS fluent simulator with the purpose of evaluating the elastic effect of the polymer in a contraction and expansion geometry. Also, using the Eulerian multiphase model, this research considers the possibility that extra elastic force will show a deformation effect on the oil; for that reason, this work considers an oil drop on the upper wall of the geometry. Finally, all the simulations exhibit that at the pore scale conditions exist extra vortices at UCM model but is not possible to deform the oil completely and push it outside of the restrictions, also this research find the conditions for the oil displacement.Keywords: ANSYS fluent, interfacial fluids mechanics, polymers, pore scale, viscoelasticity
Procedia PDF Downloads 1326545 Segmental Motion of Polymer Chain at Glass Transition Probed by Single Molecule Detection
Authors: Hiroyuki Aoki
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The glass transition phenomenon has been extensively studied for a long time. The glass transition of polymer materials is assigned to the transition of the dynamics of the chain backbone segment. However, the detailed mechanism of the transition behavior of the segmental motion is still unclear. In the current work, the single molecule detection technique was employed to reveal the trajectory of the molecular motion of the single polymer chain. The center segment of poly(butyl methacrylate) chain was labeled by a perylenediimide dye molecule and observed by a highly sensitive fluorescence microscope in a defocus condition. The translational and rotational diffusion of the center segment in a single polymer chain was analyzed near the glass transition temperature. The direct observation of the individual polymer chains revealed the intermittent behavior of the segmental motion, indicating the spatial inhomogeneity.Keywords: glass transition, molecular motion, polymer materials, single molecule
Procedia PDF Downloads 337