Search results for: total error rate
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 16784

Search results for: total error rate

15674 Total Phenols, Total Flavonoids Contents and Free Radical Scavenging Activity of Seeds Extracts of Lawsonia alba (henna) from Algeria

Authors: Rekia. Cherbi, Mokhtar. Saidi, Mohamed. Yousfi, Zhor. Rahmani

Abstract:

Lawsonia alba (Henna) is widely used in folkloric medicinal for a treatment of various skin diseases such as Eczema (atopic dermatitis), boils and sores. The aim of the present study is to determine the antioxidant activity, total phenolics, flavonoids, and condensed tannins content of extracts from the seeds of Lawsonia. alba grown in Algeria and selected from three different regions (Adrar, Biskra, and Ouargla). Total phenolics content ranged from 68,42 ± 0,54 to 88,31 ± 0,78mg gallic acid equivalents (GAE)/g dry weight, the flavonoids content varied from 1,13 ± 0,0035 to 1,367 ± 0,002mg quercetin equivalents (Q)/ g dry weight and condensed tannins (14,47 ± 0,138 to 25,50 ± 0,076 mg catechin equivalents (CE)/g dry weight). The antioxidant activities of the extracts were evaluated by DPPH assay. The results showed that all extracts from the seeds of Lawsonia. alba seem to be good trappers of radicals, the IC50 values of the extracts ranged between 0,00826 and 0,01 g/l.

Keywords: antioxidant activity, Lawsonia. alba, phenolic compounds, seeds

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15673 Formulation and Physico-Mechanical Characterization of a Self-Compacting Concrete Containing Seashells as an Addition Material

Authors: Brahim Safi, Mohammed Saidi, A. Benmounah, Jozef Mitterpach

Abstract:

The aim of this work is to study the rheological and physico-mechanical properties of a self-compacting concrete elaborated with sea shells as an addition cementitious (total replacement of limestone fillers) and sand (partial and total substitution fine aggregate). Also, this present study is registered in the context of sustainable development by using this waste type which caused environmental problems. After preparation the crushed shells (obtaining fine aggregate) and finely crushed shells (obtaining end powder), concretes were manufactured using these two products. Rheological characterization tests (fluidity, filling capacity and segregation) and physico-mechanical properties (density and strength) were carried on these concretes. The results obtained show that it can be used as fin addition (by total replacement of limestone) or also used as sand by total substitution of natural sand.

Keywords: seashells, limestone, sand, self-compacting concrete, fluidity, compressive strength, flexural strength

Procedia PDF Downloads 257
15672 A Guide to the Implementation of Ambisonics Super Stereo

Authors: Alessio Mastrorillo, Giuseppe Silvi, Francesco Scagliola

Abstract:

In this work, we introduce an Ambisonics decoder with an implementation of the C-format, also called Super Stereo. This format is an alternative to conventional stereo and binaural decoding. Unlike those, this format conveys audio information from the horizontal plane and works with stereo speakers and headphones. The two C-format channels can also return a reconstructed planar B-format. This work provides an open-source implementation for this format. We implement an all-pass filter for signal quadrature, as required by the decoding equations. This filter works with six Biquads in a cascade configuration, with values for control frequency and quality factor discovered experimentally. The phase response of the filter delivers a small error in the 20-14.000Hz range. The decoder has been tested with audio sources up to 192kHz sample rate, returning pristine sound quality and detailed stereo image. It has been included in the Envelop for Live suite and is available as an open-source repository. This decoder has applications in Virtual Reality and 360° audio productions, music composition, and online streaming.

Keywords: ambisonics, UHJ, quadrature filter, virtual reality, Gerzon, decoder, stereo, binaural, biquad

Procedia PDF Downloads 78
15671 Mechanical Properties and Microstructures of the Directional Solidified Zn-Al-Cu Alloy

Authors: Mehmet Izzettin Yilmazer, Emin Cadirli

Abstract:

Zn-7wt.%Al-2.96wt.%Cu eutectic alloy was directionally solidified upwards with different temperature gradients (from 6.70 K/mm to 10.67 K/mm) at a constant growth rate (16.4 Km/s) and also different growth rate (from 8.3 micron/s to 166 micron/s) at a constant temperature gradient (10.67 K/mm) using a Bridgman–type growth apparatus.The values of eutectic spacing were measured from longitudinal and transverse sections of the samples. The dependency of microstructures on the G and V were determined with linear regression analysis and experimental equations were found as λl=8.953xVexp-0.49, λt=5.942xVexp-0.42 and λl=0.008xGexp-1.23, λt=0.024xGexp-0.93. The measurements of microhardness of directionally solidified samples were obtained by using a microhardness test device. The dependence of microhardness HV on temperature gradient and growth rate were analyzed. The dependency of microhardness on the G and V were also determined with linear regression analysis as HVl=110.66xVexp0.02, HVt=111.94xVexp0.02 and HVl=69.66xGexp0.17, HVt=68.86xGexp0.18. The experimental results show that the microhardness of the directionally solidified Zn-Al-Cu alloy increases with increasing the growth rate. The results obtained in this work were compared with the previous similar experimental results.

Keywords: directional solidification, eutectic alloys, microstructure, microhardness

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15670 Multi-Objective Optimization in Carbon Abatement Technology Cycles (CAT) and Related Areas: Survey, Developments and Prospects

Authors: Hameed Rukayat Opeyemi, Pericles Pilidis, Pagone Emanuele

Abstract:

An infinitesimal increase in performance can have immense reduction in operating and capital expenses in a power generation system. Therefore, constant studies are being carried out to improve both conventional and novel power cycles. Globally, power producers are constantly researching on ways to minimize emission and to collectively downsize the total cost rate of power plants. A substantial spurt of developmental technologies of low carbon cycles have been suggested and studied, however they all have their limitations and financial implication. In the area of carbon abatement in power plants, three major objectives conflict: The cost rate of the plant, Power output and Environmental impact. Since, an increase in one of this parameter directly affects the other. This poses a multi-objective problem. It is paramount to be able to discern the point where improving one objective affects the other. Hence, the need for a Pareto-based optimization algorithm. Pareto-based optimization algorithm helps to find those points where improving one objective influences another objective negatively and stops there. The application of Pareto-based optimization algorithm helps the user/operator/designer make an informed decision. This paper sheds more light on areas that multi-objective optimization has been applied in carbon abatement technologies in the last five years, developments and prospects.

Keywords: gas turbine, low carbon technology, pareto optimal, multi-objective optimization

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15669 An Adaptive Hybrid Surrogate-Assisted Particle Swarm Optimization Algorithm for Expensive Structural Optimization

Authors: Xiongxiong You, Zhanwen Niu

Abstract:

Choosing an appropriate surrogate model plays an important role in surrogates-assisted evolutionary algorithms (SAEAs) since there are many types and different kernel functions in the surrogate model. In this paper, an adaptive selection of the best suitable surrogate model method is proposed to solve different kinds of expensive optimization problems. Firstly, according to the prediction residual error sum of square (PRESS) and different model selection strategies, the excellent individual surrogate models are integrated into multiple ensemble models in each generation. Then, based on the minimum root of mean square error (RMSE), the best suitable surrogate model is selected dynamically. Secondly, two methods with dynamic number of models and selection strategies are designed, which are used to show the influence of the number of individual models and selection strategy. Finally, some compared studies are made to deal with several commonly used benchmark problems, as well as a rotor system optimization problem. The results demonstrate the accuracy and robustness of the proposed method.

Keywords: adaptive selection, expensive optimization, rotor system, surrogates assisted evolutionary algorithms

Procedia PDF Downloads 129
15668 Robust Data Image Watermarking for Data Security

Authors: Harsh Vikram Singh, Ankur Rai, Anand Mohan

Abstract:

In this paper, we propose secure and robust data hiding algorithm based on DCT by Arnold transform and chaotic sequence. The watermark image is scrambled by Arnold cat map to increases its security and then the chaotic map is used for watermark signal spread in middle band of DCT coefficients of the cover image The chaotic map can be used as pseudo-random generator for digital data hiding, to increase security and robustness .Performance evaluation for robustness and imperceptibility of proposed algorithm has been made using bit error rate (BER), normalized correlation (NC), and peak signal to noise ratio (PSNR) value for different watermark and cover images such as Lena, Girl, Tank images and gain factor .We use a binary logo image and text image as watermark. The experimental results demonstrate that the proposed algorithm achieves higher security and robustness against JPEG compression as well as other attacks such as addition of noise, low pass filtering and cropping attacks compared to other existing algorithm using DCT coefficients. Moreover, to recover watermarks in proposed algorithm, there is no need to original cover image.

Keywords: data hiding, watermarking, DCT, chaotic sequence, arnold transforms

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15667 Improvement Anaerobic Digestion Performance of Sewage Sludge by Co-Digestion with Cattle Manure

Authors: Raouf Hassan

Abstract:

Biogas energy production from sewage sludge is an economically feasible and eco-friendly in nature. Sewage sludge is considered nutrient-rich substrates, but had lower values of carbone which consider an energy source for anaerobic bacteria. The lack or lower values of carbone-to-nitrogen ratio (C/N) reduced biogas yield and fermentation rate. Anaerobic co-digestion of sewage sludge offers several benefits over mono-digestion such as optimize nutrient balance, increased cost-efficiency and increased degradation rate. The high produced amounts of animal manures, which reach up to 90% of the total collected organic wastes, are recommended for the co-digestion with sewage sludge, especially with the limitations of industrial substrates. Moreover, cattle manures had high methane production potential (500 m3/t vsadded). When mixed with sewage sludge the potential methane production increased with increasing cattle manure content. In this paper, the effect of cattle manure (CM) addition as co-substrates on the sewage sludge (SS) anaerobic digestion performance was investigated under mesophilic conditions (35°C) using anaerobic batch reactors. The batch reactors were operated with a working volume 0.8 liter, and a hydraulic retention time of 30 days. The research work focus on studying two main parameters; the biogas yield (expressed as VSS) and pH values inside the reactors.

Keywords: anaerobic digestion, sewage sludge, cattle manure, mesophilic, biogas yield, pH

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15666 Intermittent Demand Forecast in Telecommunication Service Provider by Using Artificial Neural Network

Authors: Widyani Fatwa Dewi, Subroto Athor

Abstract:

In a telecommunication service provider, quantity and interval of customer demand often difficult to predict due to high dependency on customer expansion strategy and technological development. Demand arrives when a customer needs to add capacity to an existing site or build a network in a new site. Because demand is uncertain for each period, and sometimes there is a null demand for several equipments, it is categorized as intermittent. This research aims to improve demand forecast quality in Indonesia's telecommunication service providers by using Artificial Neural Network. In Artificial Neural Network, the pattern or relationship within data will be analyzed using the training process, followed by the learning process as validation stage. Historical demand data for 36 periods is used to support this research. It is found that demand forecast by using Artificial Neural Network outperforms the existing method if it is reviewed on two criteria: the forecast accuracy, using Mean Absolute Deviation (MAD), Mean of the sum of the Squares of the Forecasting Error (MSE), Mean Error (ME) and service level which is shown through inventory cost. This research is expected to increase the reference for a telecommunication demand forecast, which is currently still limited.

Keywords: artificial neural network, demand forecast, forecast accuracy, intermittent, service level, telecommunication

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15665 A Monocular Measurement for 3D Objects Based on Distance Area Number and New Minimize Projection Error Optimization Algorithms

Authors: Feixiang Zhao, Shuangcheng Jia, Qian Li

Abstract:

High-precision measurement of the target’s position and size is one of the hotspots in the field of vision inspection. This paper proposes a three-dimensional object positioning and measurement method using a monocular camera and GPS, namely the Distance Area Number-New Minimize Projection Error (DAN-NMPE). Our algorithm contains two parts: DAN and NMPE; specifically, DAN is a picture sequence algorithm, NMPE is a relatively positive optimization algorithm, which greatly improves the measurement accuracy of the target’s position and size. Comprehensive experiments validate the effectiveness of our proposed method on a self-made traffic sign dataset. The results show that with the laser point cloud as the ground truth, the size and position errors of the traffic sign measured by this method are ± 5% and 0.48 ± 0.3m, respectively. In addition, we also compared it with the current mainstream method, which uses a monocular camera to locate and measure traffic signs. DAN-NMPE attains significant improvements compared to existing state-of-the-art methods, which improves the measurement accuracy of size and position by 50% and 15.8%, respectively.

Keywords: monocular camera, GPS, positioning, measurement

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15664 Debris' Effect on Bearing Capacity of Defective Piles in Sand

Authors: A. M. Nasr, W. R. Azzam, K. E. Ebeed

Abstract:

For bored piles, careful cleaning must be used to reduce the amount of material trapped in the drilled hole; otherwise, the debris' presence might cause the soft toe effect, which would affect the axial resistance. There isn't much comprehensive research on bored piles with debris. In order to investigate the behavior of a single pile, a pile composite foundation, a two pile group, a three pile group and a four pile group investigation conducts, forty-eight numerical tests in which the debris is simulated using foam rubber.1m pile diameter and 10m length with spacing 3D and depth of foundation 1m used in this study. It is found that the existence of debris causes a reduction of bearing capacity by 64.58% and 33.23% for single pile and pile composite foundation, respectively, 23.27% and 24.24% for the number of defective piles / total number of pile =1/2 and 1 respectively for two group pile, 10.23%, 19.42% and 28.47% for the number of defective piles / total number of pile =1/3,2/3 and 1 respectively for three group pile and, this reduction increase with the increase in a number of defective piles / a total number of piles and 7.1%, 13.32%,19.02% and 26.36 for the number of defective piles / total number of pile =1/4,2/4,3/4 and 1 respectively for four group pile and decreases with an increase of number of pile duo to interaction effect.

Keywords: debris, Foundation, defective, interaction, board pile

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15663 Exergy Losses Relation with Driving Forces in Heat Transfer Process

Authors: S. Ali Ashrafizadeh, M. Amidpour, N. Hedayat

Abstract:

Driving forces along with transfer coefficient affect on heat transfer rate, on the other hand, with regard to the relation of these forces with irriversibilities they are effective on exergy losses. Therefore, the driving forces can be used as a relation between heat transfer rate, transfer coefficients and exergy losses. In this paper, first, the relation of the exergetic efficiency and resistant forces is obtained, next the relation between exergy efficiency, relative driving force, heat transfer rate and heat resistances is considered. In all cases, results are argued graphically. Finally, a case study inspected by obtained results.

Keywords: heat transfer, exergy losses, exergetic efficiency, driving forces

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15662 Efficiency of Natural Metabolites on Quality Milk Production in Mixed Breed Cows.

Authors: Mariam Azam, Sajjad Ur Rahman, Mukarram Bashir, Muhammad Tahir, Seemal Javaid, Jawad, Aoun Muhammad, Muhammad Zohaib, Hannan Khan

Abstract:

Products of microbial origin are of great importance as they have proved their value in healthcare and nutrition, use of these microbial metabolites acquired from partially fermented soya hulls and wheat bran along with Saccharomyces cerevisiae (DL-22 S/N) substantiates to be a great source for an increase in the total milk production and quality yield.1×109 CFU/ml cells of Saccharomyces cerevisiae (DL-22 S/N) were further grown under in-vivo conditions for the assessment of quality milk production. Two groups with twelve cows, each having the same physical characteristics (Group A and Group B), were under study, Group A was daily fed with 12gm of biological metabolites and 22% protein-pelleted feed. On the other hand, the animals of Group B were provided with no metabolites in their feed. In thirty days of trial, improvement in the overall health, body score, milk protein, milk fat, yield, incidence rate of mastitis, ash, and solid not fat (SNF) was observed. The collected data showed that the average quality milk production was elevated up to 0.45 liter/h/d. However, a reduction in the milk fats up to 0.45% and uplift in the SNF value up to 0.53% of cow milk was also observed. At the same time, the incidence rate of mastitis recorded for the animals under trial was reduced to half, and improved non specific immunity was reported.

Keywords: microbial metabolites, post-biotics, animal supplements, animal nutrition, proteins, animal production, fermentation

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15661 Considering Uncertainties of Input Parameters on Energy, Environmental Impacts and Life Cycle Costing by Monte Carlo Simulation in the Decision Making Process

Authors: Johannes Gantner, Michael Held, Matthias Fischer

Abstract:

The refurbishment of the building stock in terms of energy supply and efficiency is one of the major challenges of the German turnaround in energy policy. As the building sector accounts for 40% of Germany’s total energy demand, additional insulation is key for energy efficient refurbished buildings. Nevertheless the energetic benefits often the environmental and economic performances of insulation materials are questioned. The methods Life Cycle Assessment (LCA) as well as Life Cycle Costing (LCC) can form the standardized basis for answering this doubts and more and more become important for material producers due efforts such as Product Environmental Footprint (PEF) or Environmental Product Declarations (EPD). Due to increasing use of LCA and LCC information for decision support the robustness and resilience of the results become crucial especially for support of decision and policy makers. LCA and LCC results are based on respective models which depend on technical parameters like efficiencies, material and energy demand, product output, etc.. Nevertheless, the influence of parameter uncertainties on lifecycle results are usually not considered or just studied superficially. Anyhow the effect of parameter uncertainties cannot be neglected. Based on the example of an exterior wall the overall lifecycle results are varying by a magnitude of more than three. As a result simple best case worst case analyses used in practice are not sufficient. These analyses allow for a first rude view on the results but are not taking effects into account such as error propagation. Thereby LCA practitioners cannot provide further guidance for decision makers. Probabilistic analyses enable LCA practitioners to gain deeper understanding of the LCA and LCC results and provide a better decision support. Within this study, the environmental and economic impacts of an exterior wall system over its whole lifecycle are illustrated, and the effect of different uncertainty analysis on the interpretation in terms of resilience and robustness are shown. Hereby the approaches of error propagation and Monte Carlo Simulations are applied and combined with statistical methods in order to allow for a deeper understanding and interpretation. All in all this study emphasis the need for a deeper and more detailed probabilistic evaluation based on statistical methods. Just by this, misleading interpretations can be avoided, and the results can be used for resilient and robust decisions.

Keywords: uncertainty, life cycle assessment, life cycle costing, Monte Carlo simulation

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15660 Injury Pattern of Field Hockey Players at Different Field Position during Game and Practice

Authors: Sujay Bisht

Abstract:

The purpose of the study was to assess and examines the pattern of injury among the field hockey players at different field position during practice & game. It was hypothesized that the backfield might have the height rate of injury, followed by midfield. Methods: university level and national level male field hockey (N=60) are selected as a subject and requested to respond an anon questionnaire. Personal characteristics of each and individual players were also collected like (age, height, weight); field hockey professional information (level of play, year of experience, playing surface); players injury history (site, types, cause etc). The rates of injury per athlete per year were also calculated. Result: Around half of the injury occurred were to the lower limbs (49%) followed by head and face (30%), upper limbs (19%) and torso region (2%). Injuries included concussion, wounds, broken nose, ligament sprain, dislocation, fracture, and muscles strain and knee injury. The ligament sprain is the highest rate (40%) among the other types of injuries. After investigation and evaluation backfield players had the highest rate of risk of injury (1.10 injury/athletes-year) followed by midfield players (0.70 injury/athlete-year), forward players (0.45 injury/athlete-year) & goalkeeper was (0.37 injury/athlete-year). Conclusion: Due to the different field position the pattern & rate of injury were different. After evaluation, lower limbs had the highest rate of injury followed by head and face, upper limbs and torso respectively. It also revealed that not only there is a difference in the rate of injury between playing the position, but also in the types of injury sustain at a different position.

Keywords: trauma, sprain, strain, astroturf, acute injury

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15659 Sustainable Development of HV Substation in Urban Areas Considering Environmental Aspects

Authors: Mahdi Naeemi Nooghabi, Mohammad Tofiqu Arif

Abstract:

Gas Insulated Switchgears by using an insulation material named SF6 (Sulphur Hexafluoride) and its significant dielectric properties have been the only choice in urban areas and other polluted industries. However, the initial investment of GIS is more than conventional AIS substation, its total life cycle costs caused to reach huge amounts of electrical market share. SF6 environmental impacts on global warming, atmosphere depletion, and decomposing to toxic gases in high temperature situation, and highest rate in Global Warming Potential (GWP) with 23900 times of CO2e and a 3200-year period lifetime was the only undeniable concern of GIS substation. Efforts of international environmental institute and their politic supports have been able to lead SF6 emission reduction legislation. This research targeted to find an appropriate alternative for GIS substations to meet all advantages in land occupation area and to improve SF6 environmental impacts due to its leakage and emission. An innovative new conceptual design named Multi-Storey prepared a new AIS design similar in land occupation, extremely low Sf6 emission, and maximum greenhouse gas emission reduction. Surprisingly, by considering economic benefits due to carbon price saving, it can earn more than $675 million during the 30-year life cycle by replacing of just 25% of total annual worldly additional GIS switchgears.

Keywords: AIS substation, GIS substation, SF6, greenhouse gas, global warming potential, carbon price, emission

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15658 Forensic Speaker Verification in Noisy Environmental by Enhancing the Speech Signal Using ICA Approach

Authors: Ahmed Kamil Hasan Al-Ali, Bouchra Senadji, Ganesh Naik

Abstract:

We propose a system to real environmental noise and channel mismatch for forensic speaker verification systems. This method is based on suppressing various types of real environmental noise by using independent component analysis (ICA) algorithm. The enhanced speech signal is applied to mel frequency cepstral coefficients (MFCC) or MFCC feature warping to extract the essential characteristics of the speech signal. Channel effects are reduced using an intermediate vector (i-vector) and probabilistic linear discriminant analysis (PLDA) approach for classification. The proposed algorithm is evaluated by using an Australian forensic voice comparison database, combined with car, street and home noises from QUT-NOISE at a signal to noise ratio (SNR) ranging from -10 dB to 10 dB. Experimental results indicate that the MFCC feature warping-ICA achieves a reduction in equal error rate about (48.22%, 44.66%, and 50.07%) over using MFCC feature warping when the test speech signals are corrupted with random sessions of street, car, and home noises at -10 dB SNR.

Keywords: noisy forensic speaker verification, ICA algorithm, MFCC, MFCC feature warping

Procedia PDF Downloads 391
15657 External Sector and Its Impact on Economic Growth of Pakistan (1990-2010)

Authors: Rizwan Fazal

Abstract:

This study investigates the behavior of external sector of Pakistan economy and its impact on economic growth, using quarterly data for the period 1990:01-2010:04. External sector indices used in this study are financial integration, net foreign assets and trade integration. Augmented Ducky fuller confirms that all variables of external sector are non-stationary at level, but at first difference it becomes stationary. The co-integration test suggests one co-integrating variables in the study. The analysis is based on Vector Auto Regression model followed by Vector Error Correction Model. The empirical findings show that financial integration play important role in increasing economic growth in Pakistan economy while trade integration has negative effect on economic growth of Pakistan in the long run. However, the short run confirms that output lag accounts for error correction. The estimated CUSUM and CUSUMQ stability test provide information that the period of the study equation remains stable.

Keywords: financial integration, trade integration, net foreign assets, gross domestic product

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15656 Comparison of Parametric and Bayesian Survival Regression Models in Simulated and HIV Patient Antiretroviral Therapy Data: Case Study of Alamata Hospital, North Ethiopia

Authors: Zeytu G. Asfaw, Serkalem K. Abrha, Demisew G. Degefu

Abstract:

Background: HIV/AIDS remains a major public health problem in Ethiopia and heavily affecting people of productive and reproductive age. We aimed to compare the performance of Parametric Survival Analysis and Bayesian Survival Analysis using simulations and in a real dataset application focused on determining predictors of HIV patient survival. Methods: A Parametric Survival Models - Exponential, Weibull, Log-normal, Log-logistic, Gompertz and Generalized gamma distributions were considered. Simulation study was carried out with two different algorithms that were informative and noninformative priors. A retrospective cohort study was implemented for HIV infected patients under Highly Active Antiretroviral Therapy in Alamata General Hospital, North Ethiopia. Results: A total of 320 HIV patients were included in the study where 52.19% females and 47.81% males. According to Kaplan-Meier survival estimates for the two sex groups, females has shown better survival time in comparison with their male counterparts. The median survival time of HIV patients was 79 months. During the follow-up period 89 (27.81%) deaths and 231 (72.19%) censored individuals registered. The average baseline cluster of differentiation 4 (CD4) cells count for HIV/AIDS patients were 126.01 but after a three-year antiretroviral therapy follow-up the average cluster of differentiation 4 (CD4) cells counts were 305.74, which was quite encouraging. Age, functional status, tuberculosis screen, past opportunistic infection, baseline cluster of differentiation 4 (CD4) cells, World Health Organization clinical stage, sex, marital status, employment status, occupation type, baseline weight were found statistically significant factors for longer survival of HIV patients. The standard error of all covariate in Bayesian log-normal survival model is less than the classical one. Hence, Bayesian survival analysis showed better performance than classical parametric survival analysis, when subjective data analysis was performed by considering expert opinions and historical knowledge about the parameters. Conclusions: Thus, HIV/AIDS patient mortality rate could be reduced through timely antiretroviral therapy with special care on the potential factors. Moreover, Bayesian log-normal survival model was preferable than the classical log-normal survival model for determining predictors of HIV patients survival.

Keywords: antiretroviral therapy (ART), Bayesian analysis, HIV, log-normal, parametric survival models

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15655 Estimates of Freshwater Content from ICESat-2 Derived Dynamic Ocean Topography

Authors: Adan Valdez, Shawn Gallaher, James Morison, Jordan Aragon

Abstract:

Global climate change has impacted atmospheric temperatures contributing to rising sea levels, decreasing sea ice, and increased freshening of high latitude oceans. This freshening has contributed to increased stratification inhibiting local mixing and nutrient transport and modifying regional circulations in polar oceans. In recent years, the Western Arctic has seen an increase in freshwater volume at an average rate of 397+-116 km3/year. The majority of the freshwater volume resides in the Beaufort Gyre surface lens driven by anticyclonic wind forcing, sea ice melt, and Arctic river runoff. The total climatological freshwater content is typically defined as water fresher than 34.8. The near-isothermal nature of Arctic seawater and non-linearities in the equation of state for near-freezing waters result in a salinity driven pycnocline as opposed to the temperature driven density structure seen in the lower latitudes. In this study, we investigate the relationship between freshwater content and remotely sensed dynamic ocean topography (DOT). In-situ measurements of freshwater content are useful in providing information on the freshening rate of the Beaufort Gyre; however, their collection is costly and time consuming. NASA’s Advanced Topographic Laser Altimeter System (ATLAS) derived dynamic ocean topography (DOT), and Air Expendable CTD (AXCTD) derived Freshwater Content are used to develop a linear regression model. In-situ data for the regression model is collected across the 150° West meridian, which typically defines the centerline of the Beaufort Gyre. Two freshwater content models are determined by integrating the freshwater volume between the surface and an isopycnal corresponding to reference salinities of 28.7 and 34.8. These salinities correspond to those of the winter pycnocline and total climatological freshwater content, respectively. Using each model, we determine the strength of the linear relationship between freshwater content and satellite derived DOT. The result of this modeling study could provide a future predictive capability of freshwater volume changes in the Beaufort-Chukchi Sea using non in-situ methods. Successful employment of the ICESat-2’s DOT approximation of freshwater content could potentially reduce reliance on field deployment platforms to characterize physical ocean properties.

Keywords: ICESat-2, dynamic ocean topography, freshwater content, beaufort gyre

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15654 Machine Learning Assisted Prediction of Sintered Density of Binary W(MO) Alloys

Authors: Hexiong Liu

Abstract:

Powder metallurgy is the optimal method for the consolidation and preparation of W(Mo) alloys, which exhibit excellent application prospects at high temperatures. The properties of W(Mo) alloys are closely related to the sintered density. However, controlling the sintered density and porosity of these alloys is still challenging. In the past, the regulation methods mainly focused on time-consuming and costly trial-and-error experiments. In this study, the sintering data for more than a dozen W(Mo) alloys constituted a small-scale dataset, including both solid and liquid phases of sintering. Furthermore, simple descriptors were used to predict the sintered density of W(Mo) alloys based on the descriptor selection strategy and machine learning method (ML), where the ML algorithm included the least absolute shrinkage and selection operator (Lasso) regression, k-nearest neighbor (k-NN), random forest (RF), and multi-layer perceptron (MLP). The results showed that the interpretable descriptors extracted by our proposed selection strategy and the MLP neural network achieved a high prediction accuracy (R>0.950). By further predicting the sintered density of W(Mo) alloys using different sintering processes, the error between the predicted and experimental values was less than 0.063, confirming the application potential of the model.

Keywords: sintered density, machine learning, interpretable descriptors, W(Mo) alloy

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15653 Assessing Artificial Neural Network Models on Forecasting the Return of Stock Market Index

Authors: Hamid Rostami Jaz, Kamran Ameri Siahooei

Abstract:

Up to now different methods have been used to forecast the index returns and the index rate. Artificial intelligence and artificial neural networks have been one of the methods of index returns forecasting. This study attempts to carry out a comparative study on the performance of different Radial Base Neural Network and Feed-Forward Perceptron Neural Network to forecast investment returns on the index. To achieve this goal, the return on investment in Tehran Stock Exchange index is evaluated and the performance of Radial Base Neural Network and Feed-Forward Perceptron Neural Network are compared. Neural networks performance test is applied based on the least square error in two approaches of in-sample and out-of-sample. The research results show the superiority of the radial base neural network in the in-sample approach and the superiority of perceptron neural network in the out-of-sample approach.

Keywords: exchange index, forecasting, perceptron neural network, Tehran stock exchange

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15652 Effect of Time and Rate of Nitrogen Application on the Malting Quality of Barley Yield in Sandy Soil

Authors: A. S. Talaab, Safaa, A. Mahmoud, Hanan S. Siam

Abstract:

A field experiment was conducted during the winter season of 2013/2014 in the barley production area of Dakhala – New Valley Governorate, Egypt to assess the effect of nitrogen rate and time of N fertilizer application on barley grain yield, yield components and N use efficiency of barley and their association with grain yield. The treatments consisted of three levels of nitrogen (0, 70 and 100 kg N/acre) and five application times. The experiment was laid out as a randomized complete block design with three replication. Results revealed that barley grain yield and yield components increased significantly in response to N rate. Splitting N fertilizer amount at several times result in significant effect on grain yield, yield components, protein content and N uptake efficiency when compared with the entire N was applied at once. Application of N at rate of 100 kg N/acre resulted in accumulation of nitrate in the subsurface soil > 30cm. When N application timing considered, less NO3 was found in the soil profile with splitting N application compared with all preplans application.

Keywords: nitrogen use efficiency, splitting N fertilizer, barley, NO3

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15651 Artificial Neural Network and Satellite Derived Chlorophyll Indices for Estimation of Wheat Chlorophyll Content under Rainfed Condition

Authors: Muhammad Naveed Tahir, Wang Yingkuan, Huang Wenjiang, Raheel Osman

Abstract:

Numerous models used in prediction and decision-making process but most of them are linear in natural environment, and linear models reach their limitations with non-linearity in data. Therefore accurate estimation is difficult. Artificial Neural Networks (ANN) found extensive acceptance to address the modeling of the complex real world for the non-linear environment. ANN’s have more general and flexible functional forms than traditional statistical methods can effectively deal with. The link between information technology and agriculture will become more firm in the near future. Monitoring crop biophysical properties non-destructively can provide a rapid and accurate understanding of its response to various environmental influences. Crop chlorophyll content is an important indicator of crop health and therefore the estimation of crop yield. In recent years, remote sensing has been accepted as a robust tool for site-specific management by detecting crop parameters at both local and large scales. The present research combined the ANN model with satellite-derived chlorophyll indices from LANDSAT 8 imagery for predicting real-time wheat chlorophyll estimation. The cloud-free scenes of LANDSAT 8 were acquired (Feb-March 2016-17) at the same time when ground-truthing campaign was performed for chlorophyll estimation by using SPAD-502. Different vegetation indices were derived from LANDSAT 8 imagery using ERADAS Imagine (v.2014) software for chlorophyll determination. The vegetation indices were including Normalized Difference Vegetation Index (NDVI), Green Normalized Difference Vegetation Index (GNDVI), Chlorophyll Absorbed Ratio Index (CARI), Modified Chlorophyll Absorbed Ratio Index (MCARI) and Transformed Chlorophyll Absorbed Ratio index (TCARI). For ANN modeling, MATLAB and SPSS (ANN) tools were used. Multilayer Perceptron (MLP) in MATLAB provided very satisfactory results. For training purpose of MLP 61.7% of the data, for validation purpose 28.3% of data and rest 10% of data were used to evaluate and validate the ANN model results. For error evaluation, sum of squares error and relative error were used. ANN model summery showed that sum of squares error of 10.786, the average overall relative error was .099. The MCARI and NDVI were revealed to be more sensitive indices for assessing wheat chlorophyll content with the highest coefficient of determination R²=0.93 and 0.90 respectively. The results suggested that use of high spatial resolution satellite imagery for the retrieval of crop chlorophyll content by using ANN model provides accurate, reliable assessment of crop health status at a larger scale which can help in managing crop nutrition requirement in real time.

Keywords: ANN, chlorophyll content, chlorophyll indices, satellite images, wheat

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15650 The School-to-Work Transition: The Case of NEET Youths from Rural Areas

Authors: Anđelka Stojanović, Ivan Mihajlović, Ivica Nikolić

Abstract:

In the past years, due to the financial crisis and the tightening of conditions on the labor market, young people are facing great challenges in achieving financial independence and finding their place in society. Higher unemployment rates, poorer living conditions, separation from the labor market, and longer school-to-work transitions particularly affect rural youth and make significant differences between youth groups in rural and urban areas. Improving employability skills and development of instruments for further learning among young people “Not in Education, Employment, or Training” (NEET) should not be only the concerns of these people, already adequately be directed and supported by the institutions. According to the World Bank data, the share of youth not in education, employment or training (NEET), in the European Union in the past few years decreases but still shows a significant share in the total percentage of the youth population. In 2017 rate was 10.96% while in 2018 that value was 10.38%. When observing individual countries in Europe, especially those with lower incomes, this rate is much higher. It was concluded that this topic was not sufficiently elaborated and presented in the social and scientific environment. Therefore, the aim of this paper is to identify and systematize the problems of school-to-work transition among young NEETs living in rural areas as well as the initiatives for addressing their problems.

Keywords: NEET youth, risks and initiatives, rural youth, school-to-work transition

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15649 Does Inflation Affect Private Investment in Nigeria?

Authors: Amassoma Ditimi, Nwosa Philip Ifeakachukwu

Abstract:

This study examined the impact of inflation on private investment in Nigeria for the period 1980 to 2012. Private investment was measured by foreign direct investment and private domestic investment. The study employed the Ordinary Least Square (OLS) technique. The empirical regression estimate showed that inflation had a positive but insignificant effect on private investment in Nigeria; implying that although an increase in inflation rate leads to a corresponding increase in private investment but however the effect was found to be insignificant. Thus, the study recommended that government should prevent high inflation rate that can negatively affect private investment in Nigeria and government should also put in place appropriate facilities that are investment enhancing in order to increase the level of both domestic and foreign private investment in Nigeria.

Keywords: inflation rate, private investment, OLS, Nigeria

Procedia PDF Downloads 356
15648 Pentax Airway Scope Video Laryngoscope for Orotracheal Intubation in Children: A Randomized Controlled Trial

Authors: In Kyong Yi, Yun Jeong Chae, Jihoon Hwang, Sook-Young Lee, Jong-Yeop Kim

Abstract:

Background: Pentax airway scope (AWS) is a recently developed video laryngoscope for use in both normal and difficult airways, providing a good laryngeal view. The purpose of this randomized noninferior study was to evaluate the efficacy of the Pentax-AWS regarding intubation time, laryngeal view and ease of intubation in pediatric patients with normal airway, compared to Macintosh laryngoscope. Method: A total of 136 pediatric patients aged 1 to 10 with American Society of Anesthesiologists physical status I or II undergoing general anesthesia required orotracheal intubation were randomly allocated into two groups: Macintosh laryngoscope (n =68) and Pentax AWS (n=68). Anesthesia was induced with propofol, rocuronium, and sevoflurane. The primary outcome was intubation time. Cormack-Lehane laryngeal view grade, application of optimal laryngeal external manipulation (OELM), intubation difficulty scale (IDS), intubation failure rate and adverse events were also measured. Result: No significant difference was observed between the two groups regarding intubation time (Macintosh; 23[22-26] sec vs. Pentax; 23.5[22-27.75] sec, p=0.713). As for the laryngeal view grade, the Pentax group showed less number of grade 2a or higher grade cases compared to the Macintosh group (1/2a/2b/3; 52.9%/41.2%/4.4%/1.5% vs. 98.5%/1.5%/0%/0%, p=0.000). No optimal laryngeal external manipulation application was required in the Pentax group (38.2% vs. 0%, p=0.000). Intubation difficulty scale resulted in lower values for Pentax group (0 [0-2] vs. 0 [0-0.55], p=0.001). Failure rate was not different between the two groups (1.5% vs. 4.4%, p=0.619). Adverse event-wise, slightly higher incidence of bleeding (1.5% vs. 5.9%, p=0.172) and teeth injury (0% vs. 5.9%, p=0.042) occurred in the Pentax group. Conclusion: In conclusion, Pentax-AWS provided better laryngeal view, similar intubation time and similar success rate compared with Macintosh laryngoscope in children with normal airway. However, the risk of teeth injury might increase and warrant special attention.

Keywords: Pentax-AWS, pediatric, video laryngoscope, intubation

Procedia PDF Downloads 190
15647 An Analytical Method for Maintenance Cost Estimating Relationships of Helicopters Using Linear Programming

Authors: Meesun Sun, Yongmin Kim

Abstract:

Estimating maintenance cost is crucial in defense management because it affects military budgets and availability of equipment. When it comes to estimating maintenance cost of the deployed equipment, time series forecasting can be applied with the actual historical cost data. It is more difficult issue to estimate maintenance cost of new equipment for which the actual costs are not provided. In this underlying context, this study proposes an analytical method for maintenance cost estimating relationships (CERs) development of helicopters using linear programming. The CERs can be applied to a new helicopter because they use non-cost independent variables such as the number of engines, the empty weight and so on. In the Republic of Korea, the maintenance cost of new equipment has been usually estimated by reflecting maintenance cost to unit price ratio of the legacy equipment. This study confirms that the CERs perform well for the 10 types of airmobile helicopters in terms of mean absolute percentage error by applying leave-one-out cross-validation. The suggested method is very useful to estimate the maintenance cost of new equipment and can help in the affordability assessment of acquisition program portfolios for total life cycle systems management.

Keywords: affordability analysis, cost estimating relationship, helicopter, linear programming, maintenance cost

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15646 Traumatic Spinal Cord Injury in King Fahd Medical City: An Epidemiological Study

Authors: Saeed Alshahri

Abstract:

Introduction: Our study aims to estimate the characteristics & causes of TSCI at King Fahad Medical City (KFMC) in Riyadh city in order to hypothesize strategy for primary prevention of traumatic spinal cord injury. Method: Cross-sectional, retrospective study was conducted on all TSCI patients who aged 14 and above and who were admitted to rehabilitation center of King Fahad Medical City from January 2012 to December 2015. Furthermore, a descriptive analysis was conducted while considering factors including age, gender, marital status, educational level and causes of injury and characteristics of injury. Results: Total of 216 patients were admitted during this period, mean age was 28.94, majority of patients were male (86.5%), 71.7% of total patients were high school level of education or less, 68% were single, RTA was the main cause with 90.7% and the main result of TSCI was complete paraplegia 37%. Furthermore, statistically, we found that males are at a low risk of having incomplete paraplegia compared to female (p = 0.035, RRR=0.35). Conclusion: The rate of TSCI related to RTA has increased in Saudi Arabia in previous years despite the government’s efforts to decrease RTA. It’s clear that we need TSCI registry data developed on the basis of international data standards to have a clear idea about the exact etiology of TSCI in Saudi Arabia. This will assist in planning for primary prevention.

Keywords: traumatic spinal cord injury, road traffic accident, Saudi Arabia, spinal cord injury

Procedia PDF Downloads 334
15645 UV Functionalised Short Implants as an Alternative to Avoid Crestal Sinus Lift Procedure: Controlled Case Series

Authors: Naira Ghambaryan, Gagik Hakobyan

Abstract:

Purpose:The study was to evaluate the survival rate of short implants (5-6 mm) functionalized with UV radiation placed in the posterior segments of the atrophied maxilla. Materials and Methods:The study included 47 patients with unilateral/bilateral missing teeth and vertical atrophy of the posterior maxillary area. A total of 64 short UV-functionalized implants and 62 standard implants over 10 mm in length were placed in patients. The clinical indices included the following parameters: ISQБ MBL, OHIP-G scale. Results: For short implants, the median ISQ at placement was 62.2 for primary stability, and the median ISQ at 5 months was 69.6 ISQ. For standart implant, the mean ISQ at placement was 64.3 ISQ, and ISQ after 5 months was 71.6 ISQ. Аfter 6 months mean MBL short implants 0.87 mm, after 1 year, 1.13 mm, after 5 year was 1.48 mm. Аfter 6 months, mean MBL standard implants 0.84 mm, after 1 year, 1.24 mm, after 5 year was 1.58 mm. Mean OHIP-G scores -patients satisfaction with the implant at 4.8 ± 0.3, satisfaction with the operation 4.6 ± 0.4; satisfaction with prosthetics 4.7 ± 0.5. Cumulative 5-year short implants rates was 96.7%, standard implants was 97.4%, and prosthesis cumulative survival rate was 97.2%. Conclusions: Short implants with ultraviolet functionalization for prosthetic rehabilitation of the posterior resorbed maxilla region is a reliable, reasonable alternative to sinus lift, demonstrating fewer complications, satisfactory survival of a 5-year follow-up period, and reducing the number of additional surgical interventions and postoperative complications.

Keywords: short implant, ultraviolet functionalization, atrophic posterior maxilla, prosthodontic rehabilitation

Procedia PDF Downloads 66