Search results for: statistical simulation

Authors: A. Hassoune, M. Khafallah, A. Mesbahi, T. Bouragba

Abstract:

This work presents an improved strategy of control for charging a lithium-ion battery in an electric vehicle charging station using two charger topologies i.e. single ended primary inductor converter (SEPIC) and forward converter. In terms of rapidity and accuracy, the power system consists of a topology/control diagram that would overcome the performance constraints, for instance the power instability, the battery overloading and how the energy conversion blocks would react efficiently to any kind of perturbations. Simulation results show the effectiveness of the proposed topologies operated with a power management algorithm based on voltage/peak current mode controls. In order to provide credible findings, a low power prototype is developed to test the control strategy via experimental evaluations of the converter topology and its controls.

Keywords: battery storage buffer, charging station, electric vehicle, experimental analysis, management algorithm, switches control

Procedia PDF Downloads 154

Authors: Yi-Tun Huang, Chih-Yang Wu, Shu-Wei Huang

Abstract:

In this work, we examine fluid mixing in a full three-stream mixing channel with longitudinal vortex generators (LVGs) built on the channel bottom by numerical simulation and experiment. The effects of the asymmetrical arrangement and the attack angle of the LVGs on fluid mixing are investigated. The results show that the micromixer with LVGs at a small asymmetry index (defined by the ratio of the distance from the center plane of the gap between the winglets to the center plane of the main channel to the width of the main channel) is superior to the micromixer with symmetric LVGs and that with LVGs at a large asymmetry index. The micromixer using five mixing modules of the LVGs with an attack angle between 16.5 degrees and 22.5 degrees can achieve excellent mixing over a wide range of Reynolds numbers. Here, we call a section of channel with two pairs of staggered asymmetrical LVGs a mixing module. Besides, the micromixer with LVGs at a small attack angle is more efficient than that with a larger attack angle when pressure losses are taken into account.

Keywords: microfluidics, mixing, longitudinal vortex generators, two stream interfaces

Procedia PDF Downloads 502

Authors: Shuang Qiu, Zhipeng Chen, Lingfeng Wang, Shijian Ge

Abstract:

Biowastes are a concern due to the large amounts of commercial food required for model animals during the biomedical research. Searching for sustainable food alternatives with negligible physiological effects on animals is critical to solving or reducing this challenge. Microalgae have been demonstrated as suitable for both human consumption and animal feed in addition to biofuel and bioenergy applications. In this study, the possibility of using Chlorella vulgaris and Senedesmus obliquus as a feed replacement to Drosophila melanogaster, one of the fly models commonly used in biomedical studies, was investigated to assess the fly locomotor activity, motor pattern, lifespan, and body weight. Compared to control, flies fed on 60% or 80% (w/w) microalgae exhibited varied walking performance including travel distance and apparent step size, and flies treated with 40% microalgae had shorter lifespans and decreased body weight. However, the 20% microalgae treatment showed no statistical differences in all parameters tested with respect to the control. When partially including 20% microalgae in the standard food, it can annually reduce the food waste (~ 202 kg) by 22.7 % and save $ 7,200 of the food cost, offering an environmentally superior and cost-effective food alternative without compromising physiological performance.

Keywords: animal feed, Chlorella vulgaris, Drosophila melanogaster, food waste, microalgae

Procedia PDF Downloads 151

Authors: Siamack A. Shirazi, Farzin Darihaki

Abstract:

Solid particles could be found in many multiphase flows, including transport pipelines and pipe fittings. Such particles interact with the pipe material and cause erosion which threats the integrity of the system. Therefore, predicting the erosion rate is an important factor in the design and the monitor of such systems. Mechanistic models can provide reliable predictions for many conditions while demanding only relatively low computational cost. Mechanistic models utilize a representative particle trajectory to predict the impact characteristics of the majority of the particle impacts that cause maximum erosion rate in the domain. The erosion caused by particle impacts is not only due to the direct impacts but also random impingements. In the present study, an alternative model has been introduced to describe the erosion due to random impingement of particles. The present model provides a realistic trend for erosion with changes in the particle size and particle Stokes number. The present model is examined against the experimental data and CFD simulation results and indicates better agreement with the data incomparison to the available models in the literature.

Keywords: erosion, mechanistic modeling, particles, multiphase flow, gas-liquid-solid

Procedia PDF Downloads 158

Authors: Michaela Chovancova, Jakub Elcner

Abstract:

Real bronchial tree is very complicated piping system. Analysis of flow and pressure losses in this system is very difficult. Due to the complex geometry and the very small size in the lower generations is examination by CFD possible only in the central part of bronchial tree. For specify the pressure losses of lower generations is necessary to provide a mathematical equation. Determination of mathematical formulas for calculating the pressure losses in the real lungs is due to its complexity and diversity lengthy and inefficient process. For these calculations is necessary the lungs to slightly simplify (same cross-section over the length of individual generation) or use one of the models of lungs. The simplification could cause deviations from real values. The article compares the values of pressure losses obtained from CFD simulation of air flow in the central part of the real bronchial tree with the values calculated in a slightly simplified real lungs by using a mathematical relationship derived from the Bernoulli equation and continuity equation. Then, evaluate the desirability of using this formula to determine the pressure loss across the bronchial tree.

Keywords: pressure gradient, airways resistance, real geometry of bronchial tree, breathing

Procedia PDF Downloads 313

Authors: Issam Aouari, Abdelmalek Abdelhamid

Abstract:

For seismologists, the characterization of seismic demand should include the amplitude and duration of strong shaking in the system. The duration of ground shaking is one of the key parameters in earthquake resistant design of structures. This paper proposes a nonlinear statistical model to estimate earthquake ground motion duration in soft soils using multiple seismicity indicators. Three definitions of ground motion duration proposed by literature have been applied. With a comparative study, we select the most significant definition to use for predict the duration. A stochastic model is presented for the McCann and Shah Method using nonlinear regression analysis based on a data set for moment magnitude, source to site distance and site conditions. The data set applied is taken from PEER strong motion databank and contains shallow earthquakes from different regions in the world; America, Turkey, London, China, Italy, Chili, Mexico...etc. Main emphasis is placed on soft site condition. The predictive relationship has been developed based on 600 records and three input indicators. Results have been compared with others published models. It has been found that the proposed model can predict earthquake ground motion duration in soft soils for different regions and sites conditions.

Keywords: duration, earthquake, prediction, regression, soft soil

Procedia PDF Downloads 140

Authors: Oluyinka Ojedokun, S. E. Idemudia

Abstract:

In Nigeria, statistics is a compulsory course required from all social sciences students as part of their academic training. However, a rising number of social sciences undergraduates usually express statistics anxiety. The prevalence of statistics anxiety among undergraduates in social sciences has created a growing concern for educators and researchers in the higher education institutions, mainly because this statistics anxiety adversely affects their performance in statistics and research methods courses. From a societal perspective it is important to reverse this trend. Although scholars and researchers have highlighted some psychosocial factors that influence statistics anxiety in students but few empirical studies exist on the association between personality traits of NEO five factors and statistics anxiety. It is in the light of this situation that this study was designed to assess the extent to which the personality traits of NEO five factors influence statistics anxiety of students in social sciences courses. The participants were 282 undergraduates in the faculty of social sciences at a state owned public university in Nigeria. The findings demonstrate that the personality traits contributing to statistics anxiety include openness to experience, conscientious, extraversion, and neuroticism. These results imply that statistics anxiety is related to individual differences in personality traits and suggest that certain aspects of statistics anxiety may be relatively stable and resistant to change. An effective and simple method to reduce statistics anxiety among social sciences students is to create awareness of the statistical and methodological requirements of the social sciences courses before commencement of their programmes.

Keywords: personality traits, statistics anxiety, social sciences, students

Procedia PDF Downloads 519

Authors: S. Barbaqadze, M. Goderdzishvili, E. Mosidze, L. Lomtadze, V. Mshvildadze, L. Bakuridze, D. Berashvili, A. Bakuridze

Abstract:

This paper focuses on the formulation of phytobiotic designated for further implantation in poultry farming. Composition was meant to be water-soluble powder containing antibacterial essential oils. The development process involved Thyme, Monarda and Clary sage essential oils. The antimicrobial activity of essential oils composite was meant to be tested against gram-negative and gram-positive bacterial strains. The results are processed using the statistical program Sigma STAT. To make essential oils composition water soluble surfactants were added to them. At the first stage of the study, nine options for the optimal composition of essential oils and surfactants were developed. The effect of the amount of surfactants on the essential oils composition solubility in water has been investigated. On the basis of biopharmaceutical studies, the formulation of phytobiotic has been determined: Thyme, monarda and clary sage essential oils 2:1:1 - 100 parts; Licorice extract 5.25 parts and inhalation lactose 300 parts. A technology for the preparation of phytobiotic has been developed and a technological scheme for the preparation of phytobiotic has been made up. The research was performed within the framework of the grant project CARYS-19-363 funded be the Shota Rustaveli National Science Foundation of Georgia.

Keywords: clary, essential oils, monarda, phytobiotics, poultry, thyme

Procedia PDF Downloads 148

Authors: Atefeh Esmailnejad, Gholam Reza Nikbakht Brujeni

Abstract:

The major histocompatibility complex (MHC) is the best-characterized genetic region associated with susceptibility and/or resistance to a wide range of infectious diseases, autoimmune diseases and immune responses to vaccines. It has been demonstrated that there is an association between the MHC and resistance to Marek disease, Newcastle disease, Rous sarcoma tumor, Avian leucosis, Fowl cholera, Salmonellosis and Pasteurellosis in chicken. The present study evaluated the MHC polymorphism and its association with antibody response to Newcastle (ND) vaccine in Iranian native chickens. The MHC polymorphism was investigated using LEI0258 microsatellite locus by PCR-based fragment analysis. LEI0258 microsatellite marker is a genetic indicator for MHC, which is located on microchromosome 16 and strongly associated with serologically defined MHC haplotypes. Antibody titer against ND vaccine was measured by Haemaglutination Inhibition (HI) assay. Statistical analysis was performed using SPSS software (version 21). Total of 13 LEI0258 microsatellite alleles were identified in 72 samples which indicated a high genetic diversity in the population. The association study revealed a significant influence of MHC alleles on immune responses to Newcastle vaccine. 311 and 313 bp alleles were significantly associated with elevated immune responses to Newcastle vaccine (p<0.05). These results would be applicable in designing and improving the populations under selective breeding.

Keywords: chicken, LEI0258, MHC, Newcastle vaccine

Procedia PDF Downloads 419

Authors: Yi Huang, Clemens Guehmann

Abstract:

In order to monitor the thermal behavior of an asynchronous machine with squirrel cage rotor, a 9th-order extended Kalman filter (EKF) algorithm is implemented to estimate the temperatures of the stator windings, the rotor cage and the stator core. The state-space equations of EKF are established based on the electrical, mechanical and the simplified thermal models of an asynchronous machine. The asynchronous machine with simplified thermal model in Dymola is compiled as DymolaBlock, a physical model in MATLAB/Simulink. The coolant air temperature, three-phase voltages and currents are exported from the physical model and are processed by EKF estimator as inputs. Compared to the temperatures exported from the physical model of the machine, three parts of temperatures can be estimated quite accurately by the EKF estimator. The online EKF estimator is independent from the machine control algorithm and can work under any speed and load condition if the stator current is nonzero current system.

Keywords: asynchronous machine, extended Kalman filter, resistance, simulation, temperature estimation, thermal model

Procedia PDF Downloads 273

Authors: Faramarz Khosravi, Gokhan Izbirak

Abstract:

A weighted statistical stochastic based Analytical Hierarchy Process (AHP) model for modeling the potential barriers and enablers of sustainability for measuring and assessing the sustainability level is proposed. For context-dependent potential barriers and enablers, the proposed model takes the basis of the properties of the variables describing the sustainability functions and was developed into a realistic analytical model for the sustainable behavior of an organization. This thus serves as a means for measuring the sustainability of the organization. The main focus of this paper was the application of the AHP tool in a statistically-based model for measuring sustainability. Hence a strong weighted stochastic AHP based procedure was achieved. A case study scenario of a widely reported major Canadian electric utility was adopted to demonstrate the applicability of the developed model and comparatively examined its results with those of an equal-weighted model method. Variations in the sustainability of a company, as fluctuations, were figured out during the time. In the results obtained, sustainability index for successive years changed form 73.12%, 79.02%, 74.31%, 76.65%, 80.49%, 79.81%, 79.83% to more exact values 73.32%, 77.72%, 76.76%, 79.41%, 81.93%, 79.72%, and 80,45% according to priorities of factors that have found by expert views, respectively. By obtaining relatively necessary informative measurement indicators, the model can practically and effectively evaluate the sustainability extent of any organization and also to determine fluctuations in the organization over time.

Keywords: AHP, sustainability fluctuation, environmental indicators, performance measurement

Procedia PDF Downloads 106

Authors: Theodore Grosch, Felipe Koji Godinho Hoshino

Abstract:

In wireless communications, 3GPP LTE is one of the solutions to meet the greater transmission data rate demand. One issue inherent to this technology is the PAPR (Peak-to-Average Power Ratio) of OFDM (Orthogonal Frequency Division Multiplexing) modulation. This high PAPR affects the efficiency of power amplifiers. One approach to mitigate this effect is the Crest Factor Reduction (CFR) technique. In this work, we simulate the impact of Hard Limited Clipping Crest Factor Reduction technique on BER (Bit Error Rate) in OFDM based Systems. In general, the results showed that CFR has more effects on higher digital modulation schemes, as expected. More importantly, we show the worst-case degradation due to CFR on QPSK, 16QAM, and 64QAM signals in a linear system. For example, hard clipping of 9 dB results in a 2 dB increase in signal to noise energy at a 1% BER for 64-QAM modulation.

Keywords: bit error rate, crest factor reduction, OFDM, physical layer simulation

Procedia PDF Downloads 351

Authors: Roudabeh Vakil Monfared, Farhad Mashayekhi

Abstract:

Breast cancer is the most common malignancy type among women with about 1 million new cases each year. The immune system plays an important role in the breast cancer development. OX40L (also known as TNFSF4), a membrane protein, which is a member of the tumor necrosis factor super family binds to its receptor OX40 and this co-stimulation has a crucial role in T-cell proliferation, survival and cytokine release. Due to the importance of the T-cells in anti-tumor activities of OX40L we studied the association of rs3850641 (T→C) polymorphism of OX40L gene with breast cancer. The study included 123 women with breast cancer and 126 healthy volunteers with no signs of cancer. Genomic DNA was extracted from blood leucocytes. Genotype and allele frequencies were determined in patients and control cases with the method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and the analysis was performed by Med Calc. The prevalence of genotype frequencies of TT, CT and CC were 60.9%, 30.08% and 8.9 % in patients with breast cancer and 74.6 %, 18.25 % and 7.14 % in healthy volunteers while the T and C allelic frequency was 76.01% and 23.98 % in patients and 83.73% and 16.26% in healthy controls. Respectively Statistical analysis has shown no significant difference from the comparison of either genotype (P=0.06). According to these results, the rs3850641 SNP has no association with the susceptibility of breast cancer in a population in northern Iran. However, further studies in larger populations including other genetic and environmental factors are required to achieve conclusion.

Keywords: OX40L, gene, polymorphism, breast cancer

Procedia PDF Downloads 522

Authors: Hamidreza Khodaei, Ali Daryabeigi Zand

Abstract:

Conjugated linoleic acid (CLA) is a mixture of isomers of linoleic acid. Despite the fact that 28 different isomers of CLA have already been identified, but the main isomer found in natural diets more than ninety percent CLA on intake of food constitutes demonstrates. CLA is known to be a substance that readily available by rumen microorganisms in some ruminants such as cattle and sheep would likely be made. The main objective of this research was to evaluate the impacts of CLA on lipid metabolism and enhanced fat around the muscle durability by reducing the process of oxidation. In order to implement this research, 80 female mice of the Balb/C, with 55 days of age were employed in the experiment. Treatments include various levels of CLA. Over the course of this study blood samples was also taken from the tail vein of the studied mice. Some other relevant parameters such as serum concentrations of triglycerides, total cholesterol, LDL, HDL and liver enzymes were also determined. The oxidative stability of fats TBARS technique was investigated at different intervals. The findings of the research were analyzed by statistical software of SAS 98. The results, CLA had no significant effect on liver enzymes (P > 0.05). However, it showed a statistically significant impact on triglycerides and total cholesterol. Ratio of LDL to HDL declined remarkably. Histological studies demonstrated reduced accumulation of fat in the tissues surrounding muscles.

Keywords: conjugated linoleic acid, fat metabolism, fat retention, oxidation process

Procedia PDF Downloads 184

Authors: T. Hojageldiyev, Y. Bolmammedov

Abstract:

Increasing evidence suggests late chronotype individuals are at increased risk of developing psychopathological conditions. Our previously conducted study aimed to know the distribution of chronotypes according to age revealed that evening-types reaching a peak at age 14. While there is growing number of studies evaluating associations between chronotype and affective symptoms, to our best knowledge there are no studies addressing the issue of prevalence of anhedonia according to age groups of people. The sample included 545 healthy students between 13-21 years old from secondary schools and universities of Turkmenistan. Self-report 14 item Snaith-Hamilton Pleasure Scale (SHAPS) was used to assess hedonic tone of students. SHAPS score of 3 or higher indicates the criteria for the anhedonia. According to similarity of hedonic capacity participants divided into three age groups. Group I (age 13-14-15) includes 206 students (92 female), group II (age 16-17) includes 256 students (111 female) and group III (age 18-19-20-21) includes 83 (37 female). Statistical analysis was performed using Microsoft Excel 2013 and GraphPad Prism 7.0 programs. According to results average SHAPS scores of group I is 1.93 ± 1.94, group II 1.08 ± 1.43 and group III 1.29 ± 1.62. Students with anhedonia in group I consisted 30.5%, in group II 13,2% and in group III 12.04%. There are no gender differences. According to questionnaire results, higher prevalence of anhedonia is at the age between 13-15 than other age groups, and hedonic capacity increases as the age of students increases (p < 0.05). As a result, distribution of evening-types according to age correlates with hedonic capacity which is evening-types tends to have lower hedonic capacity.

Keywords: anhedonia, age, chronotype, hedonic capacity

Procedia PDF Downloads 151

Authors: An Guo, Hieyong Jeong, Tianyi Wang, Na Li, Yuko Ohno

Abstract:

Acupuncture, known as sensory simulation, has been used to treat various disorders for thousands of years. However, present studies had not addressed approaches for noninvasive measurement in order to evaluate therapeutic effect of acupuncture. The purpose of this study is to propose a noninvasive method to evaluate acupuncture by measuring facial temperature through thermal image. Three human subjects were recruited in this study. Each subject received acupuncture therapy for 30 mins. Acupuncture needles (Ø0.16 x 30 mm) were inserted into Baihui point (DU20), Neiguan points (PC6) and Taichong points (LR3), acupuncture needles (Ø0.18 x 39 mm) were inserted into Tanzhong point (RN17), Zusanli points (ST36) and Yinlingquan points (SP9). Facial temperature was recorded by an infrared thermometer. Acupuncture therapeutic effect was compared pre- and post-acupuncture. Experiment results demonstrated that facial temperature changed according to acupuncture therapeutic effect. It was concluded that proposed method showed high potential to evaluate acupuncture by noninvasive measurement of facial temperature.

Keywords: acupuncture, facial temperature, noninvasive evaluation, thermal image

Procedia PDF Downloads 168

Authors: Avijit Sengupta, Klarissa Ting Ting Cheng, Maffee Peng-Hui Wan

Abstract:

This study investigates the influence of user factors and referent characteristics on representation types generated using the stereotype production method for designing icons. Sixty-eight participants of farming communities were asked to draw images based on sixteen feature referents. Significant statistical differences were found between the types of representations generated for contextual and context-independent referents. Strong correlations were observed between years of formal education and total number of abstract representations produced for both contextual and context-independent referents. However, representation characteristics were not influenced by other user factors such as participants’ experience with mobile phone and years of farming experience. A statistically significant tendency of making concrete representations was observed for both contextual and context-independent referents. These findings provide insights on community members’ involvement in icon design and suggest a consolidated icon design strategy based on population stereotype, particularly for under-served rural communities of India.

Keywords: abstract representation, concrete representation, participatory design, population stereotype

Procedia PDF Downloads 363

Authors: Ahmed H. El-Masry, Mohamed A. Dabaon, Tarek F. El-Shafiey, Abd El-Hakim A. Khalil

Abstract:

An experimental study was performed to investigate the behavior and strength of proposed technique to connect reinforced concrete (RC) beam to steel or composite columns. This approach can practically be used in several types of building construction. In this technique, the main beam of the frame consists of a transfer part (part of beam; Tr.P) and a common reinforcement concrete beam. The transfer part of the beam is connected to the column, whereas the rest of the beam is connected to the transfer part from each side. Four full-scale beam-column connections were tested under static loading. The test parameters were the length of the transfer part and the column properties. The test results show that using of the transfer part technique leads to modify the deformation capabilities for the RC beam and hence it increases its resistance against failure. Increase in length of the transfer part did not necessarily indicate an enhanced behavior. The test results contribute to the characterization of the connection behavior between RC beam - steel column and can be used to calibrate numerical models for the simulation of this type of connection.

Keywords: composite column, reinforced concrete beam, steel column, transfer part

Procedia PDF Downloads 420

Authors: Pham Van Hung, Nguyen Trong Hieu, Le Quoc Dinh, Nguyen Kiem Chien, Le Dinh Hieu

Abstract:

The article focuses on the study of automatic flight control on missiles during operation. The quality standards and characteristics of missile operations are very strict, requiring high stability and accurate response to commands within a relatively wide range of work. The study analyzes the linear transfer function model of the Missile Roll channel to facilitate the development of control systems. A two-loop control structure for the Missile Roll channel is proposed, with the inner loop controlling the Missile Roll rate and the outer loop controlling the Missile Roll angle. To determine the optimal control parameters, a genetic algorithm is applied. The study uses MATLAB simulation software to implement the genetic algorithm and evaluate the quality of the closed-loop system. The results show that the system achieves better quality than the original structure and is simple, reliable, and ready for implementation in practical experiments.

Keywords: genetic algorithm, roll chanel, two-loop control structure, missile

Procedia PDF Downloads 72

Authors: T. Yuri, M. Zagloel, Inaki M. Hakim, Tegu Bintang Nugraha

Abstract:

In an era of customer centricity, automotive parts manufacturer in Indonesia must be able to keep up with the uncertainty and fluctuation of consumer demand. Flexible Manufacturing System (FMS) is a strategy to react to predicted and unpredicted changes of demand in automotive industry. This research is about flexible mixed model assembly line design through Value Stream Mapping (VSM) and Line Balancing in mixed model assembly line prior to simulation. It uses value stream mapping to identify and reduce waste while finding the best position to add or reduce manpower. Line balancing is conducted to minimize or maximize production rate while increasing assembly line productivity and efficiency. Results of this research is a recommendation of standard work combination for specifics demand scenario which can enhance assembly line efficiency and productivity.

Keywords: automotive industry, demand uncertainty, flexible assembly system, line balancing, value stream mapping

Procedia PDF Downloads 316

Authors: Klaudia Tomala, Elzbieta Grochowska-Niedworok, Katarzyna Brukalo, Marek Kardas, Beata Calyniuk, Renata Polaniak

Abstract:

Background. Nutrition plays an important role in the psychophysical growth of children and has effects on their health. Providing children with the appropriate supply of macro- and micro-nutrients requires dietary diversity across every food group. Meals in kindergartens should provide 70-75% of their daily food requirement. Aim. The aim of this study was to determine the vitamin content in the food rations of children attending kindergarten in the wider aspect of nutritional status. Material and Methods. Kindergarten menus from the spring and autumn seasons of 2015 were analyzed. In these meals, fat content and levels of water-soluble vitamins were estimated. The vitamin content was evaluated using the diet calculator “Aliant”. Statistical analysis was done in MS Office Excel 2007. Results. Vitamin content in the analyzed menus in many cases is too high with reference to dietary intake, with only vitamin D intake being insufficient. Vitamin E intake was closest to the dietary reference intake. Conclusion. The results show that vitamin intake is usually too high, and menus should, therefore, be modified. Also, nutrition education among kindergarten staff is needed. The identified errors in the composition of meals will affect the nutritional status of children and their proper composition in the body.

Keywords: children, nutrition status, vitamins, preschool

Procedia PDF Downloads 144

Authors: Huilan Yao, Huaixin Zhang

Abstract:

Simulations of the transition flow of model propellers are important for predicting hydrodynamic performance and studying scale effects. In this paper, the transition flow of a model propeller under different loadings are simulated using a transition model provided by STAR-CCM+, and the influence of turbulence intensity (TI) on the transition, especially friction and pressure components of propeller performance, was studied. Before that, the transition model was applied to simulate the transition flow of a flat plate and an airfoil. Predicted transitions agree well with experimental results. Then, the transition model was applied for propeller simulations in open water, and the influence of TI was studied. Under the heavy and moderate loadings, thrust and torque of the propeller predicted by the transition model (different TI) and two turbulence models are very close and agree well with measurements. However, under the light loading, only the transition model with low TI predicts the most accurate results. Above all, the friction components of propeller performance predicted by the transition model with different TI have obvious difference.

Keywords: transition flow, model propellers, hydrodynamic performance, numerical simulation

Procedia PDF Downloads 247

Authors: Qinghua Xing, Noha M. Mesbah, Haisheng Wang, Jun Li, Baisuo Zhao

Abstract:

Droplet digital PCR (ddPCR) is being increasingly adopted for gene detection and quantification because of its higher sensitivity and specificity. According to previous observations and our lab data, it is essential to use endogenous reference genes (RGs) when investigating gene expression at the mRNA level under salt stress. This study aimed to select and validate suitable RGs for gene expression under salt stress using ddPCR. Six candidate RGs were selected based on the tandem mass tag (TMT)-labeled quantitative proteomics of Alkalicoccus halolimnae at four salinities. The expression stability of these candidate genes was evaluated using statistical algorithms (geNorm, NormFinder, BestKeeper and RefFinder). There was a small fluctuation in cycle threshold (Ct) value and copy number of the pdp gene. Its expression stability was ranked in the vanguard of all algorithms, and was the most suitable RG for quantification of expression by both qPCR and ddPCR of A. halolimnae under salt stress. Single RG pdp and RG combinations were used to normalize the expression of ectA, ectB, ectC, and ectD under four salinities. The present study constitutes the first systematic analysis of endogenous RG selection for halophiles responding to salt stress. This work provides a valuable theory and an approach reference of internal control identification for ddPCR-based stress response models.

Keywords: endogenous reference gene, salt stress, ddPCR, RT-qPCR, Alkalicoccus halolimnae

Procedia PDF Downloads 82

Authors: Adeola Adejumo, Oluwole David Adebayo, Muraina Kamilu Olanrewaju

Abstract:

The purpose of this study was to investigate the influence of some psychological factors (i.e, school climate, parental involvement and classroom interaction) on the learning gains of university undergraduates in Mathematics in Ibadan, Nigeria. Three hundred undergraduates who are on open distance learning education programme in the University of Ibadan and thirty mathematics lecturers constituted the study’s sample. Both the independent and dependent variables were measured with relevant standardized instruments and the data obtained was analyzed using multiple regression statistical method. The instruments used were school climate scale, parental involvement scale and classroom interaction scale. Three research questions were answered in the study. The result showed that there was significant relationship between the three independent variables (school climate, parental involvement and classroom interaction) on the students’ learning gain in mathematics and that the independent variables both jointly and relatively contributed significantly to the prediction of students’ learning gain in mathematics. On the strength of these findings, the need to enhance the school climate, improve the parents’ involvement in the student’s education and encourage students’ classroom interaction were stressed and advocated.

Keywords: school climate, parental involvement, ODL, learning gains, mathematics

Procedia PDF Downloads 482

Authors: Sutan Emir Hidayat, Latifa Hassan Al-Qassab

Abstract:

The purpose of this study is to examine depositors’ awareness on the pursuit of corporate social responsibilities (CSR) conducted by Islamic retail banks in the Kingdom of Bahrain according to the Accounting and Auditing Organization for Islamic Financial Institutions (AAOIFI) standards. The outcome of the paper is the extent to which the depositors knew about the banks’ CSR activities in promoting the welfare of the society beyond their business objectives. The study covered all Islamic retail banks in the Kingdom of Bahrain where a survey questionnaire was distributed to a total of 200 Islamic banks' depositors. The results of the survey show that the level of depositors’ awareness is limited on the pursuit of corporate social responsibilities by the banks as indicated by the small number of statements in the survey questionnaire which the respondents agreed to or of which they had satisfactory knowledge. The significant statistical difference in the respondents' answers to the survey questionnaire when they are grouped according to their respective banks prove that the level of depositors’ awareness on the pursuit of corporate social responsibilities varies considerably among the six Islamic retail banks in the kingdom. The findings of the study might be used to assist the policy makers in the field of CSR of Islamic financial institutions in formulation of better CSR activities and in delivering better services for the public welfare. The study also might help Islamic banks in the kingdom to set up strategy in order to increase the level of depositors’ awareness on their CSR activities.

Keywords: corporate social responsibilities, awareness, Islamic banks, Bahrain

Procedia PDF Downloads 396

Authors: Adewale I. Adeolu, Vivian U. Oleforuh-Okoleh, Sylvester N. Ibe

Abstract:

Heritability and repeatability estimates are needed for the genetic evaluation of livestock populations and consequently for the purpose of upgrading or improvement. Pooled data on 604 progeny from three consecutive parities of purebred rabbit breeds (Chinchilla, Dutch and New Zealand white) raised in Derived Savanna Zone of Nigeria were used to estimate heritability and repeatability for pre-weaning body weights between 1st and 8th week of age. Traits studied include Individual kit weight at birth (IKWB), 2nd week (IK2W), 4th week (IK4W), 6th week (IK6W) and 8th week (IK8W). Nested random effects analysis of (Co)variances as described by Statistical Analysis System (SAS) were employed in the estimation. Respective heritability estimates from the sire component (h2s) and repeatability (R) as intra-class correlations of repeated measurements from the three parties for IKWB, IK2W, IK4W and IK8W are 0.59±0.24, 0.55±0.24, 0.93±0.31, 0.28±0.17, 0.64±0.26 and 0.12±0.14, 0.05±0.14, 0.58±0.02, 0.60±0.11, 0.20±0.14. Heritability and repeatability (except R for IKWB and IK2W) estimates are moderate to high. In conclusion, since pre-weaning body weights in the present study tended to be moderately to highly heritable and repeatable, improvement of rabbits raised in derived savanna zone can be realized through genetic selection criterions.

Keywords: heritability, nested design, parity, pooled data, repeatability

Procedia PDF Downloads 136

Authors: Amrutha Venugopal, Rabee Rustum

Abstract:

In spite of huge investments and the vital role infrastructure plays in the economy of UAE, the country has not yet developed an assessment scheme to measure the sustainability of infrastructure projects/development. The aim of this study was to develop a sustainability rating system for infrastructure projects in UAE using weighted indicator scoring. The identification of the list of 66 indicators was done by content analysis. The sources of content analysis were from government guidelines, research literature and sustainability rating system for infrastructure projects namely BCA Greenmark for Infrastructure (Singapore), ISCA (Australia) and Envision (USA). These indicators were shortlisted based on their relevance in the UAE. A mixture of qualitative and quantitative research methods is utilized to find the weightage to be applied to the indicators and to find suggestive measures to improve infrastructure sustainability in this region. Interviews and surveys were conducted with a good mix of experts from the industry. The data collected from the interviews were collated to provide suggestive measures for improving infrastructure sustainability. The collected survey data were analyzed using statistical analysis techniques to find the indicator weighing. The indicators were shortlisted by 75% to minimize the effort and investment into the process. The weighing of the deleted indicators was distributed among the critical clusters identified by Pareto analysis. Finally a simple Microsoft Excel tool was developed as the rating tool by using the calculated weighing for the indicators.

Keywords: infrastructure, rating system, suggestive measures, sustainability, UAE

Procedia PDF Downloads 288

Authors: S. Sharan Sundar, Nithish B. Moudhgalya, Nidhi Bhandari, Vineeth Vijayaraghavan

Abstract:

Automatic Short Answer Grading is one of the prime applications of artificial intelligence in education. Several approaches involving the utilization of selective handcrafted features, graphical matching techniques, concept identification and mapping, complex deep frameworks, sentence embeddings, etc. have been explored over the years. However, keeping in mind the real-world application of the task, these solutions present a slight overhead in terms of computations and resources in achieving high performances. In this work, a simple and effective solution making use of elemental features based on statistical, linguistic properties, and word-based similarity measures in conjunction with tree-based classifiers and regressors is proposed. The results for classification tasks show improvements ranging from 1%-30%, while the regression task shows a stark improvement of 35%. The authors attribute these improvements to the addition of multiple similarity scores to provide ensemble of scoring criteria to the models. The authors also believe the work could reinstate that classical natural language processing techniques and simple machine learning models can be used to achieve high results for short answer grading.

Keywords: artificial intelligence, intelligent systems, natural language processing, text mining

Procedia PDF Downloads 120

Authors: Najib K. Dankadai, Ahmad 'Athif Mohd Faudzi, Khairuddin Osman, Muhammad Rusydi Muhammad Razif, IIi Najaa Aimi Mohd Nordin

Abstract:

Researches in soft actuators are now growing rapidly because of their adequacy to be applied in sectors like medical, agriculture, biological and welfare. This paper presents system identification (SI) and control of the force generated by a two chambers pneumatic soft actuator (PSA). A force mathematical model for the actuator was identified experimentally using data acquisition card and MATLAB SI toolbox. Two control techniques; a predictive functional control (PFC) and conventional proportional integral and derivative (PID) schemes are proposed and compared based on the identified model for the soft actuator flexible mechanism. Results of this study showed that both of the proposed controllers ensure accurate tracking when the closed loop system was tested with the step, sinusoidal and multi step reference input through MATLAB simulation although the PFC provides a better response than the PID.

Keywords: predictive functional control (PFC), proportional integral and derivative (PID), soft actuator, system identification

Procedia PDF Downloads 308

Authors: Ji Chen, Chunhui Zhang, Fanming Zeng, Lei Zhang, Ying Li, Wei Zhang

Abstract:

Based on the synthetic principle of force, a pre-compressed nonlinear isolator with quasi-zero-stiffness (QZS) is developed for shock isolation of ship equipment. The proposed isolator consists of a vertical spring with positive stiffness and several lateral springs with negative stiffness. An analytical expression of vertical stiffness of the nonlinear isolator is derived and numerical simulation on the effect of the geometric design parameters is carried out. Besides, a pre-compressed QZS shock isolation system model is established. The stiffness characteristic of the system is studied and the effects of excitation amplitude and friction damping on shock isolation performance are discussed respectively. The research results show that in comparison with linear shock isolation system, the pre-compressed QZS shock isolation system could realize constant-force or approximately constant-force function and perform better anti-impact performance.

Keywords: quasi-zero-stiffness, constant-force, pre-compressed, large deformation, shock isolation, friction damping

Procedia PDF Downloads 667