Search results for: time sensitive networking
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 19754

Search results for: time sensitive networking

18734 Dependence of Densification, Hardness and Wear Behaviors of Ti6Al4V Powders on Sintering Temperature

Authors: Adewale O. Adegbenjo, Elsie Nsiah-Baafi, Mxolisi B. Shongwe, Mercy Ramakokovhu, Peter A. Olubambi

Abstract:

The sintering step in powder metallurgy (P/M) processes is very sensitive as it determines to a large extent the properties of the final component produced. Spark plasma sintering over the past decade has been extensively used in consolidating a wide range of materials including metallic alloy powders. This novel, non-conventional sintering method has proven to be advantageous offering full densification of materials, high heating rates, low sintering temperatures, and short sintering cycles over conventional sintering methods. Ti6Al4V has been adjudged the most widely used α+β alloy due to its impressive mechanical performance in service environments, especially in the aerospace and automobile industries being a light metal alloy with the capacity for fuel efficiency needed in these industries. The P/M route has been a promising method for the fabrication of parts made from Ti6Al4V alloy due to its cost and material loss reductions and the ability to produce near net and intricate shapes. However, the use of this alloy has been largely limited owing to its relatively poor hardness and wear properties. The effect of sintering temperature on the densification, hardness, and wear behaviors of spark plasma sintered Ti6Al4V powders was investigated in this present study. Sintering of the alloy powders was performed in the 650–850°C temperature range at a constant heating rate, applied pressure and holding time of 100°C/min, 50 MPa and 5 min, respectively. Density measurements were carried out according to Archimedes’ principle and microhardness tests were performed on sectioned as-polished surfaces at a load of 100gf and dwell time of 15 s. Dry sliding wear tests were performed at varied sliding loads of 5, 15, 25 and 35 N using the ball-on-disc tribometer configuration with WC as the counterface material. Microstructural characterization of the sintered samples and wear tracks were carried out using SEM and EDX techniques. The density and hardness characteristics of sintered samples increased with increasing sintering temperature. Near full densification (99.6% of the theoretical density) and Vickers’ micro-indentation hardness of 360 HV were attained at 850°C. The coefficient of friction (COF) and wear depth improved significantly with increased sintering temperature under all the loading conditions examined, except at 25 N indicating better mechanical properties at high sintering temperatures. Worn surface analyses showed the wear mechanism was a synergy of adhesive and abrasive wears, although the former was prevalent.

Keywords: hardness, powder metallurgy, spark plasma sintering, wear

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18733 The Impact of Foliar Application of the Calcium-Containing Compounds in Increasing Resistance to Blue Mold on Apples

Authors: Masoud Baghalian, Musa Arshad

Abstract:

In order to investigate the effect of foliar application of calcium chloride on the resistance of fruits such as Red and Golden Lebanese apple varieties to blue mold, a split plot experiment in time and space, based on accidental blocks, with three replications under foliar application were done (Control, one in a thousand, two in thousands) and the results of the variance analysis showed that there is a significant difference between the levels of foliar and variety at 5% level and between time, there is significant difference in interaction of variety × time and three way interaction of foliar×variety×time, at 1% level. The highest resistance to the blue mold disease in foliar application was observed at two in thousands calcium (calcium chloride) level.

Keywords: apple, blue mold, foliar calcium, resistance

Procedia PDF Downloads 265
18732 Effects of COVID-19 Confinement on Physical Activity and Screen Time in Spanish Children

Authors: Maria Medrano, Cristina Cadenas-Sanchez, Maddi Oses, Lide Arenaza, Maria Amasene, Idoia Labayen

Abstract:

The COVID-19 outbreak began in December 2019 in China and was rapidly expanded globally. Emergency measures, such as social distance or home confinement, were adopted by many country governments to prevent its transmission. In Spain, one of the most affected countries, the schools were closed, and one of the most severe mandatory home confinement was established for children from 14th March to 26th April 2020. The hypothesis of this study was that the measures adopted during the COVID-19 pandemic may have negatively affected physical activity and screen time of children. However, few studies have examined the effects of COVID-19 pandemic on lifestyle behaviours. Thus, the aim of the current work was to analyse the effects of the COVID-19 confinement on physical activity and screen time in Spanish children. For the current purpose, a total of 113 children and adolescents (12.0 ± 2.6 yr., 51.3% boys, 24.0% with overweight/obesity according to the World Obesity Federation) of the MUGI project were included in the analyses. Physical activity and screen time were longitudinally assessed by 'The Youth Activity Profile' questionnaire (YAP). Differences in physical activity and screen time before and during the confinement were assessed by dependent t-test. Before the confinement, 60% did not meet physical activity recommendations ( ≥ 60/min/day of moderate to vigorous physical activity), and 61% used screens ≥ 2 h/day. During the COVID-19 confinement, children decreased their physical activity levels (-91 ± 55 min/day, p < 0.001) and increased screen time ( ± 2.6 h/day, p < 0.001). The prevalence of children that worsened physical activity and screen time during the COVID-19 confinement were 95.2% and 69.8%, respectively. The current study evidence the negative effects of the COVID-19 confinement on physical activity and screen time in Spanish children. These findings should be taken into account to develop and implement future public health strategies for preserving children's lifestyle behaviours and health during and after the COVID-19 pandemic.

Keywords: COVID-19, lifestyle changes, paediatric, physical activity, screen time

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18731 Exposure to Radon on Air in Tourist Caves in Bulgaria

Authors: Bistra Kunovska, Kremena Ivanova, Jana Djounova, Desislava Djunakova, Zdenka Stojanovska

Abstract:

The carcinogenic effects of radon as a radioactive noble gas have been studied and show a strong correlation between radon exposure and lung cancer occurrence, even in the case of low radon levels. The major part of the natural radiation dose in humans is received by inhaling radon and its progenies, which originates from the decay chain of U-238. Indoor radon poses a substantial threat to human health when build-up occurs in confined spaces such as homes, mines and caves and the risk increases with the duration of radon exposure and is proportional to both the radon concentration and the time of exposure. Tourist caves are a case of special environmental conditions that may be affected by high radon concentration. Tourist caves are a recognized danger in terms of radon exposure to cave workers (guides, employees working in shops built above the cave entrances, etc.), but due to the sensitive nature of the cave environment, high concentrations cannot be easily removed. Forced ventilation of the air in the caves is considered unthinkable due to the possible harmful effects on the microclimate, flora and fauna. The risks to human health posed by exposure to elevated radon levels in caves are not well documented. Various studies around the world often detail very high concentrations of radon in caves and exposure of employees but without a follow-up assessment of the overall impact on human health. This study was developed in the implementation of a national project to assess the potential health effects caused by exposure to elevated levels of radon in buildings with public access under the National Science Fund of Bulgaria, in the framework of grant No КП-06-Н23/1/07.12.2018. The purpose of the work is to assess the radon level in Bulgarian caves and the exposure of the visitors and workers. The number of caves (sampling size) was calculated for simple random selection from total available caves 65 (sampling population) are 13 caves with confidence level 95 % and confidence interval (margin of error) approximately 25 %. A measurement of the radon concentration in air at specific locations in caves was done by using CR-39 type nuclear track-etch detectors that were placed by the participants in the research team. Despite the fact that all of the caves were formed in karst rocks, the radon levels were rather different from each other (97–7575 Bq/m3). An assessment of the influence of the orientation of the caves in the earth's surface (horizontal, inclined, vertical) on the radon concentration was performed. Evaluation of health hazards and radon risk exposure causing by inhaling the radon and its daughter products in each surveyed caves was done. Reducing the time spent in the cave has been recommended in order to decrease the exposure of workers.

Keywords: tourist caves, radon concentration, exposure, Bulgaria

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18730 Time Series Analysis on the Production of Fruit Juice: A Case Study of National Horticultural Research Institute (Nihort) Ibadan, Oyo State

Authors: Abiodun Ayodele Sanyaolu

Abstract:

The research was carried out to investigate the time series analysis on quarterly production of fruit juice at the National Horticultural Research Institute Ibadan from 2010 to 2018. Documentary method of data collection was used, and the method of least square and moving average were used in the analysis. From the calculation and the graph, it was glaring that there was increase, decrease, and uniform movements in both the graph of the original data and the tabulated quarter values of the original data. Time series analysis was used to detect the trend in the highest number of fruit juice and it appears to be good over a period of time and the methods used to forecast are additive and multiplicative models. Since it was observed that the production of fruit juice is usually high in January of every year, it is strongly advised that National Horticultural Research Institute should make more provision for fruit juice storage outside this period of the year.

Keywords: fruit juice, least square, multiplicative models, time series

Procedia PDF Downloads 142
18729 Detection of Chaos in General Parametric Model of Infectious Disease

Authors: Javad Khaligh, Aghileh Heydari, Ali Akbar Heydari

Abstract:

Mathematical epidemiological models for the spread of disease through a population are used to predict the prevalence of a disease or to study the impacts of treatment or prevention measures. Initial conditions for these models are measured from statistical data collected from a population since these initial conditions can never be exact, the presence of chaos in mathematical models has serious implications for the accuracy of the models as well as how epidemiologists interpret their findings. This paper confirms the chaotic behavior of a model for dengue fever and SI by investigating sensitive dependence, bifurcation, and 0-1 test under a variety of initial conditions.

Keywords: epidemiological models, SEIR disease model, bifurcation, chaotic behavior, 0-1 test

Procedia PDF Downloads 324
18728 Exploring Cybersecurity and Phishing Attacks within Healthcare Institutions in Saudi Arabia: A Narrative Review

Authors: Ebtesam Shadadi, Rasha Ibrahim, Essam Ghadafi

Abstract:

Phishing poses a significant threat as a cybercrime by tricking end users into revealing their confidential and sensitive information. Attackers often manipulate victims to achieve their malicious goals. The increasing prevalence of Phishing has led to extensive research on this issue, including studies focusing on phishing attempts in healthcare institutions in the Kingdom of Saudi Arabia. This paper explores the importance of analyzing phishing attacks, specifically focusing on those targeting the healthcare industry. The study delves into the tactics, obstacles, and remedies associated with these attacks, all while considering the implications for Saudi Vision 2030.

Keywords: phishing, cybersecurity, cyber threat, social engineering, vision 2030

Procedia PDF Downloads 61
18727 Structural Properties of Polar Liquids in Binary Mixture Using Microwave Technique

Authors: Shagufta Tabassum, V. P. Pawar

Abstract:

The study of static dielectric properties in a binary mixture of 1,2 dichloroethane (DE) and n,n dimethylformamide (DMF) polar liquids has been carried out in the frequency range of 10 MHz to 30 GHz for 11 different concentration using time domain reflectometry technique at 10ºC temperature. The dielectric relaxation study of solute-solvent mixture at microwave frequencies gives information regarding the creation of monomers and multimers as well as interaction between the molecules of the binary mixture. The least squares fit method is used to determine the values of dielectric parameters such as static dielectric constant (ε0), dielectric constant at high frequency (ε) and relaxation time (τ).

Keywords: shagufta shaikhexcess parameters, relaxation time, static dielectric constant, time domain reflectometry

Procedia PDF Downloads 243
18726 Continuous Blood Pressure Measurement from Pulse Transit Time Techniques

Authors: Chien-Lin Wang, Cha-Ling Ko, Tainsong Chen

Abstract:

Pulse Blood pressure (BP) is one of the vital signs, and is an index that helps determining the stability of life. In this respect, some spinal cord injury patients need to take the tilt table test. While doing the test, the posture changes abruptly, and may cause a patient’s BP to change abnormally. This may cause patients to feel discomfort, and even feel as though their life is threatened. Therefore, if a continuous non-invasive BP assessment system were built, it could help to alert health care professionals in the process of rehabilitation when the BP value is out of range. In our research, BP assessed by the pulse transit time technique was developed. In the system, we use a self-made photoplethysmograph (PPG) sensor and filter circuit to detect two PPG signals and to calculate the time difference. The BP can immediately be assessed by the trend line. According to the results of this study, the relationship between the systolic BP and PTT has a highly negative linear correlation (R2=0.8). Further, we used the trend line to assess the value of the BP and compared it to a commercial sphygmomanometer (Omron MX3); the error rate of the system was found to be in the range of ±10%, which is within the permissible error range of a commercial sphygmomanometer. The continue blood pressure measurement from pulse transit time technique may have potential to become a convenience method for clinical rehabilitation.

Keywords: continous blood pressure measurement, PPG, time transit time, transit velocity

Procedia PDF Downloads 353
18725 Virtualization and Visualization Based Driver Configuration in Operating System

Authors: Pavan Shah

Abstract:

In an Embedded system, Virtualization and visualization technology can provide us an effective response and measurable work in a software development environment. In addition to work of virtualization and virtualization can be easily deserved to provide the best resource sharing between real-time hardware applications and a healthy environment. However, the virtualization is noticeable work to minimize the I/O work and utilize virtualization & virtualization technology for either a software development environment (SDE) or a runtime environment of real-time embedded systems (RTMES) or real-time operating system (RTOS) eras. In this Paper, we particularly focus on virtualization and visualization overheads data of network which generates the I/O and implementation of standardized I/O (i.e., Virto), which can work as front-end network driver in a real-time operating system (RTOS) hardware module. Even there have been several work studies are available based on the virtualization operating system environment, but for the Virto on a general-purpose OS, my implementation is on the open-source Virto for a real-time operating system (RTOS). In this paper, the measurement results show that implementation which can improve the bandwidth and latency of memory management of the real-time operating system environment (RTMES) for getting more accuracy of the trained model.

Keywords: virtualization, visualization, network driver, operating system

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18724 Support Vector Regression with Weighted Least Absolute Deviations

Authors: Kang-Mo Jung

Abstract:

Least squares support vector machine (LS-SVM) is a penalized regression which considers both fitting and generalization ability of a model. However, the squared loss function is very sensitive to even single outlier. We proposed a weighted absolute deviation loss function for the robustness of the estimates in least absolute deviation support vector machine. The proposed estimates can be obtained by a quadratic programming algorithm. Numerical experiments on simulated datasets show that the proposed algorithm is competitive in view of robustness to outliers.

Keywords: least absolute deviation, quadratic programming, robustness, support vector machine, weight

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18723 A Non-Destructive Estimation Method for Internal Time in Perilla Leaf Using Hyperspectral Data

Authors: Shogo Nagano, Yusuke Tanigaki, Hirokazu Fukuda

Abstract:

Vegetables harvested early in the morning or late in the afternoon are valued in plant production, and so the time of harvest is important. The biological functions known as circadian clocks have a significant effect on this harvest timing. The purpose of this study was to non-destructively estimate the circadian clock and so construct a method for determining a suitable harvest time. We took eight samples of green busil (Perilla frutescens var. crispa) every 4 hours, six times for 1 day and analyzed all samples at the same time. A hyperspectral camera was used to collect spectrum intensities at 141 different wavelengths (350–1050 nm). Calculation of correlations between spectrum intensity of each wavelength and harvest time suggested the suitability of the hyperspectral camera for non-destructive estimation. However, even the highest correlated wavelength had a weak correlation, so we used machine learning to raise the accuracy of estimation and constructed a machine learning model to estimate the internal time of the circadian clock. Artificial neural networks (ANN) were used for machine learning because this is an effective analysis method for large amounts of data. Using the estimation model resulted in an error between estimated and real times of 3 min. The estimations were made in less than 2 hours. Thus, we successfully demonstrated this method of non-destructively estimating internal time.

Keywords: artificial neural network (ANN), circadian clock, green busil, hyperspectral camera, non-destructive evaluation

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18722 Timing Equation for Capturing Satellite Thermal Images

Authors: Toufic Abd El-Latif Sadek

Abstract:

The Asphalt object represents the asphalted areas, like roads. The best original data of thermal images occurred at a specific time during the days of the year, by preventing the gaps in times which give the close and same brightness from different objects, using seven sample objects, asphalt, concrete, metal, rock, dry soil, vegetation, and water. It has been found in this study a general timing equation for capturing satellite thermal images at different locations, depends on a fixed time the sunrise and sunset; Capture Time= Tcap =(TM*TSR) ±TS.

Keywords: asphalt, satellite, thermal images, timing equation

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18721 Risk Factor of Anal Incontinence among Women in Makassar

Authors: Azizah Nurdin, Trika Irianta, Mardiah Tahir, Maisuri T. Chalid

Abstract:

Background: Studies of anal incontinence in the general population are rare however its financial healthcare cost is significant. Women attended Hasanuddin University Teaching Hospital and its networking in Makassar, Indonesia was surveyed between February to April 2015 about their obstetrical and gynecological history. Aims: To establish obstetrical risk factor of anal incontinence among women in Makassar. Methods: In a cross sectional face to face interview study, 135 women aged 30 years or more were selected randomly. Participants were asked to complete an anal incontinence questionnaire. Results: From a total sample of 135 respondents, 42,2 % reported has flatulence incontinence. Parity, history of anal sphincter laceration, history of having large baby, history of assisted vaginal delivery were shown have no significant association with anal incontinence, while history of episiotomy was shown have a significant association with anal incontinence (p value < 0.05). The risk of flatulence incontinence was higher among women with history of episiotomy (OR : 2,85, 95 % CI = 1,58- 5,13) Conclusions: This study has confirmed that fecal incontinence is a fairly common symptom. Flatulence incontinence is the most frequent even. An obstetrical factor like episiotomy is one of risk factor that could be avoided in order to prevent anal incontinence.

Keywords: anal incontinence, flatulence incontinence, obstetrical risk factor, women

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18720 The Impact of Religiosity and Ethical Senstivity on Accounting Students’ Ethical Judgement Decision

Authors: Ahmed Mohamed Alteer

Abstract:

The purpose of this paper is come up with theoretical model through understanding the causes and motives behind the auditors' sensitive to ethical dilemma through Auditing Students. This study considers the possibility of auditing students’ ethical judgement being affected by two individual factors, namely ethical sensitivity and religiosity. The finding of this study that there are several ethical theories a models provide a significant understanding of ethical issues and supported that ethical sensitivity and religiosity may affect ethical judgement decision among accounting students. The suggestion model proposes that student ethical judgement is influenced by their ethical sensitivity and their religiosity. Nonetheless, the influence of religiosity on ethical judgement is expected to be via ethical sensitivity.

Keywords: asccounting students, ethical sensitivity, religiosity, ethical judgement

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18719 Raman Spectroscopic of Cardioprotective Mechanism During the Metabolic Inhibition of Heart Cells

Authors: A. Almohammedi, A. J. Hudson, N. M. Storey

Abstract:

Following ischaemia/reperfusion injury, as in a myocardial infraction, cardiac myocytes undergo oxidative stress which leads to several potential outcomes including; necrotic or apoptotic cell death or dysregulated calcium homeostasis or disruption of the electron transport chain. Several studies have shown that nitric oxide donors protect cardiomyocytes against ischemia and reperfusion. However until present, the mechanism of cardioprotective effect of nitric oxide donor in isolated ventricular cardiomyocytes is not fully understood and has not been investigated before using Raman spectroscopy. For these reasons, the aim of this study was to develop a novel technique, pre-resonance Raman spectroscopy, to investigate the mechanism of cardioprotective effect of nitric oxide donor in isolated ventricular cardiomyocytes exposed to metabolic inhibition and re-energisation. The results demonstrated the first time that Raman microspectroscopy technique has the capability to monitor the metabolic inhibition of cardiomyocytes and to monitor the effectiveness of cardioprotection by nitric oxide donor prior to metabolic inhibition of cardiomyocytes. Metabolic inhibition and reenergisation were used in this study to mimic the low and high oxygen levels experienced by cells during ischaemic and reperfusion treatments. A laser wavelength of 488 nm used in this study has been found to provide the most sensitive means of observe the cellular mechanisms of myoglobin during nitric oxide donor preconditioning, metabolic inhibition and re-energisation and did not cause any damage to the cells. The data also highlight the considerably different cellular responses to metabolic inhibition to ischaemia. Moreover, the data has been shown the relationship between the release of myoglobin and chemical ischemia where that the release of myoglobin from the cell only occurred if a cell did not recover contractility.

Keywords: ex vivo biospectroscopy, Raman spectroscopy, biophotonics, cardiomyocytes, ischaemia / reperfusion injury, cardioprotection, nitric oxide donor

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18718 Simulation Analysis of Wavelength/Time/Space Codes Using CSRZ and DPSK-RZ Formats for Fiber-Optic CDMA Systems

Authors: Jaswinder Singh

Abstract:

In this paper, comparative analysis is carried out to study the performance of wavelength/time/space optical CDMA codes using two well-known formats; those are CSRZ and DPSK-RZ using RSoft’s OptSIM. The analysis is carried out under the real-like scenario considering the presence of various non-linear effects such as XPM, SPM, SRS, SBS and FWM. Fiber dispersion and the multiple access interference are also considered. The codes used in this analysis are 3-D wavelength/time/space codes. These are converted into 2-D wavelength-time codes so that their requirement of space couplers and fiber ribbons is eliminated. Under the conditions simulated, this is found that CSRZ performs better than DPSK-RZ for fiber-optic CDMA applications.

Keywords: Optical CDMA, Multiple access interference (MAI), CSRZ, DPSK-RZ

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18717 Real-Time Control of Grid-Connected Inverter Based on labVIEW

Authors: L. Benbaouche, H. E. , F. Krim

Abstract:

In this paper we propose real-time control of grid-connected single phase inverter, which is flexible and efficient. The first step is devoted to the study and design of the controller through simulation, conducted by the LabVIEW software on the computer 'host'. The second step is running the application from PXI 'target'. LabVIEW software, combined with NI-DAQmx, gives the tools to easily build applications using the digital to analog converter to generate the PWM control signals. Experimental results show that the effectiveness of LabVIEW software applied to power electronics.

Keywords: real-time control, labview, inverter, PWM

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18716 Innovative Schools as Birthplaces for Promoting Educational Innovations: A Case Study of Two Hungarian Schools

Authors: Khin Khin Thant Sin

Abstract:

This study is a case study which investigates successful and ongoing bottom-up innovations for school improvement initiatives in Hungary. Two innovative schools are selected in this study due to their outstanding achievement during the past ten years in Hungary. In one school, data from the personal experiences of a school principal who initiated the bottom-up innovation are included. For the second school, three interviews were carried out with two schoolteachers and one secondary school student. In addition, desk research, including the principal’s published articles, the schoolteachers’ master thesis, the school websites, and other published articles, are analysed to explore the schools’ innovative processes. This study investigates how bottom-up innovation led to major achievements in student learning, teacher professional development, networking and collaboration with other schools, and the establishment of successful partnerships with universities. The highlight of this study is how innovative schools can be the major sources promoting educational innovations as well as improving teacher education, especially in initial teacher education and continuous professional development.

Keywords: school innovation, teacher education, hungary, educational innovation, school improvement

Procedia PDF Downloads 109
18715 Porul: Option Generation and Selection and Scoring Algorithms for a Tamil Flash Card Game

Authors: Anitha Narasimhan, Aarthy Anandan, Madhan Karky, C. N. Subalalitha

Abstract:

Games can be the excellent tools for teaching a language. There are few e-learning games in Indian languages like word scrabble, cross word, quiz games etc., which were developed mainly for educational purposes. This paper proposes a Tamil word game called, “Porul”, which focuses on education as well as on players’ thinking and decision-making skills. Porul is a multiple choice based quiz game, in which the players attempt to answer questions correctly from the given multiple options that are generated using a unique algorithm called the Option Selection algorithm which explores the semantics of the question in various dimensions namely, synonym, rhyme and Universal Networking Language semantic category. This kind of semantic exploration of the question not only increases the complexity of the game but also makes it more interesting. The paper also proposes a Scoring Algorithm which allots a score based on the popularity score of the question word. The proposed game has been tested using 20,000 Tamil words.

Keywords: Porul game, Tamil word game, option selection, flash card, scoring, algorithm

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18714 Bivariate Time-to-Event Analysis with Copula-Based Cox Regression

Authors: Duhania O. Mahara, Santi W. Purnami, Aulia N. Fitria, Merissa N. Z. Wirontono, Revina Musfiroh, Shofi Andari, Sagiran Sagiran, Estiana Khoirunnisa, Wahyudi Widada

Abstract:

For assessing interventions in numerous disease areas, the use of multiple time-to-event outcomes is common. An individual might experience two different events called bivariate time-to-event data, the events may be correlated because it come from the same subject and also influenced by individual characteristics. The bivariate time-to-event case can be applied by copula-based bivariate Cox survival model, using the Clayton and Frank copulas to analyze the dependence structure of each event and also the covariates effect. By applying this method to modeling the recurrent event infection of hemodialysis insertion on chronic kidney disease (CKD) patients, from the AIC and BIC values we find that the Clayton copula model was the best model with Kendall’s Tau is (τ=0,02).

Keywords: bivariate cox, bivariate event, copula function, survival copula

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18713 Synthesis, Structural and Magnetic Properties of CdFe2O4 Ferrite

Authors: Justice Zakhele Msomi

Abstract:

Nanoparticles of CdFe2O4 with particle size of about 10 nm have been synthesized by high energy ball milling and co-precipitation processes. The synthesis route appears to have some effects on the properties. The compounds have been characterized by X-ray diffraction, Fourier Transform Infrared (FTIR), transmission electron microscopy (TEM), Mössbauer and magnetization measurements. The XRD pattern of CdFe2O4 provides information about single-phase formation of spinel structure with cubic symmetry. The FTIR measurements between 400 and 4000 cm-1 indicate intrinsic cation vibration of the spinel structure. The Mössbauer spectra were recorded at 4 K and 300 K. The hyperfine fields appear to be highly sensitive on particle size. The evolution of the properties as a function of particle size is also presented.

Keywords: ferrite, nanoparticles, magnetization, Mössbauer

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18712 Application of a SubIval Numerical Solver for Fractional Circuits

Authors: Marcin Sowa

Abstract:

The paper discusses the subinterval-based numerical method for fractional derivative computations. It is now referred to by its acronym – SubIval. The basis of the method is briefly recalled. The ability of the method to be applied in time stepping solvers is discussed. The possibility of implementing a time step size adaptive solver is also mentioned. The solver is tested on a transient circuit example. In order to display the accuracy of the solver – the results have been compared with those obtained by means of a semi-analytical method called gcdAlpha. The time step size adaptive solver applying SubIval has been proven to be very accurate as the results are very close to the referential solution. The solver is currently able to solve FDE (fractional differential equations) with various derivative orders for each equation and any type of source time functions.

Keywords: numerical method, SubIval, fractional calculus, numerical solver, circuit analysis

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18711 The Relationship between Land Use Change and Runoff

Authors: Thanutch Sukwimolseree, Preeyaphorn Kosa

Abstract:

Many problems are occurred in watershed due to human activity and economic development. The purpose is to determine the effects of the land use change on surface runoff using land use map on 1980, 2001 and 2008 and daily weather data during January 1, 1979 to September 30, 2010 applied to SWAT. The results can be presented that the polynomial equation is suitable to display that relationship. These equations for land use in 1980, 2001 and 2008 are consisted of y = -0.0076x5 + 0.1914x4–1.6386x3 + 6.6324x2–8.736x + 7.8023(R2 = 0.9255), y = -0.0298x5 + 0.8794x4 - 9.8056x3 + 51.99x2 - 117.04x + 96.797; (R2 = 0.9186) and y = -0.0277x5 + 0.8132x4 - 8.9598x3 + 46.498x2–101.83x +81.108 (R2 = 0.9006), respectively. Moreover, if the agricultural area is the largest area, it is a sensitive parameter to concern surface runoff.

Keywords: land use, runoff, SWAT, upper Mun River basin

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18710 Old Swimmers Tire Quickly: The Effect of Time on Quality of Thawed versus Washed Sperm

Authors: Emily Hamilton, Adiel Kahana, Ron Hauser, Shimi Barda

Abstract:

BACKGROUND: In the male fertility and sperm bank unit of Tel Aviv Sourasky medical center, women are treated with intrauterine insemination (IUI) using washed sperm from their partner or thawed sperm from a selected donor. In most cases, the women perform the IUI treatment in Sourasky, but sometimes they ask to undergo the insemination procedure in another clinic with their own fertility doctor. In these cases, the sperm sample is prepared at the Sourasky lab and the patient is inseminated after arriving to her doctor. Our laboratory has previously found that time negatively affects several parameters of thawed sperm, and we estimate that it has more severe and significant effect than on washed sperm. AIM: To examine the effect of time on the quality of washed sperm versus thawed sperm. METHODS: Sperm samples were collected from men referred for semen analysis. Each ejaculate was allowed to liquefy for at least 20 min at 37°C and analyzed for sperm motility and vitality percentage and DNA fragmentation index (Time 0). Subsequently, 1ml of the sample was divided into two parts, 1st part was washed only and the 2nd part was washed, frozen and thawed. Time 1 analysis occurred immediately after sperm washing or thawing. Time 2 analysis occurred 75 minutes after time 1. Statistical analysis was performed using Student t-test. P values<0.05 were considered significant. RESULTS: Preliminary data showed that time had a greater impact on the average percentages of sperm motility and vitality in thawed compared to washed sperm samples (26%±10% vs. 21%±10% and 21%±9% vs. 9%±10%, respectively). An additional trend towards increased average DNA fragmentation percentage in thawed samples compared to washed samples was observed (46%±18% vs. 25%±24%). CONCLUSION: Time negatively effects sperm quality. The effect is greater in thawed samples compared to fresh samples.

Keywords: ART, male fertility, sperm cryopreservation, sperm quality

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18709 Development and Psychometric Properties of the Dutch Contextual Assessment of Social Skills: A Blinded Observational Outcome Measure of Social Skills for Adolescents with Autism Spectrum Disorder

Authors: Sakinah Idris, Femke Ten Hoeve, Kirstin Greaves-Lord

Abstract:

Background: Social skills interventions are considered to be efficacious if social skills are improved as a result of an intervention. Nevertheless, the objective assessment of social skills is hindered by a lack of sensitive and validated measures. To measure the change in social skills after an intervention, questionnaires reported by parents, clinicians and/or teachers are commonly used. Observations are the most ecologically valid method of assessing improvements in social skills after an intervention. For this purpose, The Program for the Educational and Enrichment of Relational Skills (PEERS) was developed for adolescents, in order to teach them the age-appropriate skills needed to participate in society. It is an evidence-based intervention for adolescents with ASD that taught ecologically valid social skills techniques. Objectives: The current study aims to describe the development and psychometric evaluation of the Dutch Contextual Assessment of Social Skills (CASS), an observational outcome measure of social skills for adolescents with Autism Spectrum Disorder (ASD). Methods: 64 adolescents (M = 14.68, SD = 1.41, 71% boys) with ASD performed the CASS before and after a social skills intervention (i.e. PEERS or the active control condition). Each adolescent completed a 3-minute conversation with a confederate. The conversation was prompt as a natural introduction between two-unfamiliar, similar ages, opposite-sex peers who meet for the first time. The adolescent and the confederate completed a brief questionnaire about the conversation (Conversation Rating Scale). Results: Results indicated sufficient psychometric properties. The Dutch CASS has a high level of internal consistency (Cronbach's α coefficients = 0.84). Data supported the convergent validity (i.e., significant correlated with the Social Skills Improvement System (SSiS). The Dutch CASS did not significantly correlate with the autistic mannerism subscale from Social Responsiveness Scale (SRS), thus proved the divergent validity. Based on scorings made by raters who were kept blind to the time points, reliable change index was computed to assess the change in social skills. With regard to the content validity, only the learning objectives of the first two meetings of PEERS about conversational skills relatively matched with rating domains of the CASS. Due to this underrepresentation, we found an existing observational measure (TOPICC) that covers some of the other learning objectives of PEERS. TOPICC covers 22% of the learning objectives of PEERS about conversational skills, meanwhile, CASS is 45%. Unfortunately, 33% of the learning objectives of PEERS was not covered by CASS or TOPICC. Conclusion: Recommendations are made to improve the psychometric properties and content validity of the Dutch CASS.

Keywords: autism spectrum disorder, observational, PEERS, social skills

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18708 Approximation of the Time Series by Fractal Brownian Motion

Authors: Valeria Bondarenko

Abstract:

In this paper, we propose two problems related to fractal Brownian motion. First problem is simultaneous estimation of two parameters, Hurst exponent and the volatility, that describe this random process. Numerical tests for the simulated fBm provided an efficient method. Second problem is approximation of the increments of the observed time series by a power function by increments from the fractional Brownian motion. Approximation and estimation are shown on the example of real data, daily deposit interest rates.

Keywords: fractional Brownian motion, Gausssian processes, approximation, time series, estimation of properties of the model

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18707 Upon One Smoothing Problem in Project Management

Authors: Dimitri Golenko-Ginzburg

Abstract:

A CPM network project with deterministic activity durations, in which activities require homogenous resources with fixed capacities, is considered. The problem is to determine the optimal schedule of starting times for all network activities within their maximal allowable limits (in order not to exceed the network's critical time) to minimize the maximum required resources for the project at any point in time. In case when a non-critical activity may start only at discrete moments with the pregiven time span, the problem becomes NP-complete and an optimal solution may be obtained via a look-over algorithm. For the case when a look-over requires much computational time an approximate algorithm is suggested. The algorithm's performance ratio, i.e., the relative accuracy error, is determined. Experimentation has been undertaken to verify the suggested algorithm.

Keywords: resource smoothing problem, CPM network, lookover algorithm, lexicographical order, approximate algorithm, accuracy estimate

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18706 Toward a Characteristic Optimal Power Flow Model for Temporal Constraints

Authors: Zongjie Wang, Zhizhong Guo

Abstract:

While the regular optimal power flow model focuses on a single time scan, the optimization of power systems is typically intended for a time duration with respect to a desired objective function. In this paper, a temporal optimal power flow model for a time period is proposed. To reduce the computation burden needed for calculating temporal optimal power flow, a characteristic optimal power flow model is proposed, which employs different characteristic load patterns to represent the objective function and security constraints. A numerical method based on the interior point method is also proposed for solving the characteristic optimal power flow model. Both the temporal optimal power flow model and characteristic optimal power flow model can improve the systems’ desired objective function for the entire time period. Numerical studies are conducted on the IEEE 14 and 118-bus test systems to demonstrate the effectiveness of the proposed characteristic optimal power flow model.

Keywords: optimal power flow, time period, security, economy

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18705 Venezuela in the US Oil Geopolitics: An Analysis in the Light of the New Oil Landscape

Authors: William Clavijo, Edmar Almeida

Abstract:

The article analyzes the importance of Venezuela in the US geopolitics of oil considering the new oil landscape. To this end, the importance of oil in the geopolitics of the United States is discussed from the perspective of energy security as well as considering a broader view of national security. Based on this discussion, the relevance of Venezuelan oil reserves on US geopolitical agenda is analyzed. Among the results, the article shows that the transformations in the supply structure of the international oil market during the last decade have allowed the United States to achieve greater levels of independence from oil imports from other producing countries. This new reality has profoundly changed the US interest in Venezuelan oil to a broader subject that involves sensitive issues of its national security agenda.

Keywords: oil geopolitics, Venezuela, United States, energy security, national security

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