Search results for: growth variables
1104 Secure Power Systems Against Malicious Cyber-Physical Data Attacks: Protection and Identification
Authors: Morteza Talebi, Jianan Wang, Zhihua Qu
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The security of power systems against malicious cyberphysical data attacks becomes an important issue. The adversary always attempts to manipulate the information structure of the power system and inject malicious data to deviate state variables while evading the existing detection techniques based on residual test. The solutions proposed in the literature are capable of immunizing the power system against false data injection but they might be too costly and physically not practical in the expansive distribution network. To this end, we define an algebraic condition for trustworthy power system to evade malicious data injection. The proposed protection scheme secures the power system by deterministically reconfiguring the information structure and corresponding residual test. More importantly, it does not require any physical effort in either microgrid or network level. The identification scheme of finding meters being attacked is proposed as well. Eventually, a well-known IEEE 30-bus system is adopted to demonstrate the effectiveness of the proposed schemes.Keywords: Algebraic Criterion, Malicious Cyber-Physical Data Injection, Protection and Identification, Trustworthy Power System.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19851103 Bioethanol: Indonesian Macro-Algae as a Renewable Feedstock for Liquid Fuel
Authors: T. Poespowati, E. Marsyahyo, R. Kartika-Dewi
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This experimental study aims at studying the conversion of macro-algae into bioethanol under several steps of procedure: preparation, pre-treatment, fermentation, and distillation. The main objective of this work was to investigate the role of buffer’s type as a stabiliser of pH level and fermentation time on the yield of ethanol. For this purpose, experiments were carried out on biomass macro-algae to de-couple the pre-treatment and fermentation processes from those associated with distillation process. β- glucosidase was used as cellulose decomposer during hydrolysis step and yeast was used during fermentation process. The species of macro-algae utilised as energy feedstock was Ulva lactuca and it was harvested from southern coast of Central of Java Island – Indonesia. Experiments were conducted in a simple fermenter over a different buffer: citrate buffer and acetic buffer, and over a range of fermentation times between 5 to 20 days. The ethanol production was found to be significantly affected by both variables. The optimum time of fermentation was 10 days with citrate buffer; result in 0.88458% of ethanol, and the ethanol content after distillation process was shown 0.985015%.
Keywords: Fermentation, ulva-lactuca, buffer, β-glucosidase, bioethanol.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24271102 Nile Red, an Alternative Fluorescence Method for Quantification of Neutral Lipids in Microalgae
Authors: P. Rattanapoltee, P. Kaewkannetra
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According to biodiesel from microalgae is an attractive fuel for several reasons such as renewable, biodegradable and environmental friendly. Thus, this study, green microalgae Scenedesmus acutus PPNK1 isolated from natural water, was selected based on high growth rates, easy cultivation and high lipid content. The Nile red fluorescence method has been successfully applied to the determination of lipids in S. acutus PPNK1. The combination of the method to the lipid composition in algal cells showed the yellow fluorescence under fluorescent microscope. Interestingly, maximum cell numbers and biomass concentration were obtained at 5.44´107 cells/mL and 1.60 g/L when it was cultivated in BG-11 medium while in case of BG-11 with nitrogen deprivation (N 0.25 g/L), accumulated lipid content in cells (44.67%) was achieved that was higher than that found in case of BG-11 medium at about 2 times (22.63%).
Keywords: Biodiesel, Lipid, Microalgae, Nile red.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 69781101 Order Optimization of a Telecommunication Distribution Center through Service Lead Time
Authors: Tamás Hartványi, Ferenc Tóth
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European telecommunication distribution center performance is measured by service lead time and quality. Operation model is CTO (customized to order) namely, a high mix customization of telecommunication network equipment and parts. CTO operation contains material receiving, warehousing, network and server assembly to order and configure based on customer specifications. Variety of the product and orders does not support mass production structure. One of the success factors to satisfy customer is to have a proper aggregated planning method for the operation in order to have optimized human resources and highly efficient asset utilization. Research will investigate several methods and find proper way to have an order book simulation where practical optimization problem may contain thousands of variables and the simulation running times of developed algorithms were taken into account with high importance. There are two operation research models that were developed, customer demand is given in orders, no change over time, customer demands are given for product types, and changeover time is constant.
Keywords: CTO, aggregated planning, demand simulation, changeover time.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7801100 Kinetic model and Simulation Analysis for Propane Dehydrogenation in an Industrial Moving Bed Reactor
Authors: Chin S. Y., Radzi, S. N. R., Maharon, I. H., Shafawi, M. A.
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A kinetic model for propane dehydrogenation in an industrial moving bed reactor is developed based on the reported reaction scheme. The kinetic parameters and activity constant are fine tuned with several sets of balanced plant data. Plant data at different operating conditions is applied to validate the model and the results show a good agreement between the model predictions and plant observations in terms of the amount of main product, propylene produced. The simulation analysis of key variables such as inlet temperature of each reactor (Tinrx) and hydrogen to total hydrocarbon ratio (H2/THC) affecting process performance is performed to identify the operating condition to maximize the production of propylene. Within the range of operating conditions applied in the present studies, the operating condition to maximize the propylene production at the same weighted average inlet temperature (WAIT) is ΔTinrx1= -2, ΔTinrx2= +1, ΔTinrx3= +1 , ΔTinrx4= +2 and ΔH2/THC= -0.02. Under this condition, the surplus propylene produced is 7.07 tons/day as compared with base case.Keywords: kinetic model, dehydrogenation, simulation, modeling, propane
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 44071099 A Secure Proxy Signature Scheme with Fault Tolerance Based on RSA System
Authors: H. El-Kamchouchi, Heba Gaber, Fatma Ahmed, Dalia H. El-Kamchouchi
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Due to the rapid growth in modern communication systems, fault tolerance and data security are two important issues in a secure transaction. During the transmission of data between the sender and receiver, errors may occur frequently. Therefore, the sender must re-transmit the data to the receiver in order to correct these errors, which makes the system very feeble. To improve the scalability of the scheme, we present a secure proxy signature scheme with fault tolerance over an efficient and secure authenticated key agreement protocol based on RSA system. Authenticated key agreement protocols have an important role in building a secure communications network between the two parties.
Keywords: Proxy signature, fault tolerance, RSA, key agreement protocol.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14721098 Assessing the Antimicrobial Activity of Chitosan Nanoparticles by Fluorescence-Labeling
Authors: Laidson P. Gomes, Cristina T. Andrade, Eduardo M. Del Aguila, Cameron Alexander, Vânia M. F. Paschoalin
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Chitosan is a natural polysaccharide prepared by the N-deacetylation of chitin. In this study, the physicochemical and antibacterial properties of chitosan nanoparticles, produced by ultrasound irradiation, were evaluated. The physicochemical properties of the nanoparticles were determined by dynamic light scattering and zeta potential analysis. Chitosan nanoparticles inhibited the growth of E. coli. The minimum inhibitory concentration (MIC) values were lower than 0.5 mg/mL, and the minimum bactericidal concentration (MBC) values were similar or higher than MIC values. Confocal laser scanning micrographs (CLSM) were used to observe the interaction between E. coli suspensions mixed with FITC-labeled chitosan polymers and nanoparticles.
Keywords: Chitosan nanoparticles, dynamic light scattering, zeta potential, confocal microscopy, antibacterial activity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10581097 Optimal Economic Restructuring Aimed at an Increase in GDP Constrained by a Decrease in Energy Consumption and CO2 Emissions
Authors: Alexander Y. Vaninsky
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The objective of this paper is finding the way of economic restructuring - that is, change in the shares of sectoral gross outputs - resulting in the maximum possible increase in the gross domestic product (GDP) combined with decreases in energy consumption and CO2 emissions. It uses an input-output model for the GDP and factorial models for the energy consumption and CO2 emissions to determine the projection of the gradient of GDP, and the antigradients of the energy consumption and CO2 emissions, respectively, on a subspace formed by the structure-related variables. Since the gradient (antigradient) provides a direction of the steepest increase (decrease) of the objective function, and their projections retain this property for the functions' limitation to the subspace, each of the three directional vectors solves a particular problem of optimal structural change. In the next step, a type of factor analysis is applied to find a convex combination of the projected gradient and antigradients having maximal possible positive correlation with each of the three. This convex combination provides the desired direction of the structural change. The national economy of the United States is used as an example of applications.
Keywords: Economic restructuring, Input-Output analysis, Divisia index, Factorial decomposition, E3 models.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16011096 A Green Chemical Technique for the Synthesis of Magnetic Nanoparticles by Magnetotactic Bacteria
Authors: Parisa Tajer-Mohammad-Ghazvini, Rouha Kasra-Kermanshahi, Ahmad Nozad-Golikand, Majid Sadeghizadeh
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Bacterial magnetic nanoparticles have great useful potential in biotechnological and biomedical applications. In this study, a liquid growth medium was modified for cultivation a fastidious magnetotactic bacterium that has been isolated from Anzali lagoon, Iran in our previous research. These modifications include change in vitamin, mineral, carbon sources and etcetera. In our experience, the serum bottles and designed air-tight laboratory bottles were used to create microaerobic conditions in order to development of a method for scale-up experiment. This information may serve as a guide to green chemistry based biological protocols for the synthesis of magnetic nanoparticles with control over the chemical composition, morphology and size.Keywords: Green chemistry, Magnetosome, Magnetotactic bacteria, Magnetic nanoparticles, Nano-Biotechnology.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 40121095 Corporate Governance in Network Marketing Organizations: The Role of Ethics and CSR
Authors: Venugopal Kummamuru
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Corporate Governance (CG) is of utmost importance for running a company ethically. It is essential for the growth and success of the corporation. It is intended to increase the accountability of an organization to the larger context of the business environment. The general principles of CG include and are related to Shareholder recognition, Stakeholder interests, and focus on Corporate Social Responsibility (CSR), Clear Board responsibilities, Ethical behavior, and Business transparency. Network Marketing Organizations (NMOs) focus on marketing through direct-sales using people who are associated with the organization but are not their employees. This paper tries to study the importance of Ethics and CSR in an NMO and suggest a basic guideline for CG in NMO(s). This paper could be used as a basis or starting point for conducting an in-depth research to understand the difference in CG practices between NMO(s) and other organizations and define a standard set of guidelines for CG practice.
Keywords: Corporate governance, corporate responsibility, direct selling, network marketing.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20671094 Effect of Subsequent Drying and Wetting on the Small Strain Shear Modulus of Unsaturated Soils
Authors: A. Khosravi, S. Ghadirian, J. S. McCartney
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Evaluation of the seismic-induced settlement of an unsaturated soil layer depends on several variables, among which the small strain shear modulus, Gmax, and soil’s state of stress have been demonstrated to be of particular significance. Recent interpretation of trends in Gmax revealed considerable effects of the degree of saturation and hydraulic hysteresis on the shear stiffness of soils in unsaturated states. Accordingly, the soil layer is expected to experience different settlement behaviors depending on the soil saturation and seasonal weathering conditions. In this study, a semi-empirical formulation was adapted to extend an existing Gmax model to infer hysteretic effects along different paths of the SWRC including scanning curves. The suitability of the proposed approach is validated against experimental results from a suction-controlled resonant column test and from data reported in literature. The model was observed to follow the experimental data along different paths of the SWRC, and showed a slight hysteresis in shear modulus along the scanning curves.Keywords: Hydraulic hysteresis, Scanning path, Small strain shear modulus, Unsaturated soil.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15661093 Effect of Selenite and Selenate Uptake by Maize Plants on Specific Leaf Area
Authors: F. Garousi, Sz. Veres, É. Bódi, Sz. Várallyay, B. Kovács
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Specific leaf area (SLA; cm2leaf g-1leaf) the ratio of leaf area to leaf dry mass is a key ecophysiological parameter influencing leaf physiology, photosynthesis, and whole plant carbon gain and also can be used as a rapid and diagnostic tool. In this study, two species of soluble inorganic selenium forms, selenite (Se^IV) and selenate (Se^VI) at different concentrations were investigated on maize plants that were growing in nutrient solutions during 2 weeks and at the end of the experiment, amounts of SLA for first and second leaves of maize were measured. In accordance with the results we observed that our regarded Se concentrations in both forms of Se^IV and Se^VI were not effective on maize plants’ SLA significantly although high level of 3 mg.kg-1 Se^IV had negative affect on growth of the samples that had been treated by it but about Se^VI samples we did not observe this state and our different considered Se^VI concentrations were not toxic for maize plants.
Keywords: Maize, Sodium selenate, sodium selenite, specific leaf area.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18801092 A Quantitative Assessment of the Social Marginalization in Romania
Authors: Andra Costache, Rădiţa Alexe
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The analysis of the spatial disparities of social marginalization is a requirement in the present-day socio-economic and political context of Romania, an East-European state, member of the European Union since 2007, at present faced with the imperatives of the growth of its territorial cohesion. The main objective of this article is to develop a methodology for the assessment of social marginalization, in order to understand the intensity of the marginalization phenomenon at different spatial scales. The article proposes a social marginalization index (SMI), calculated through the integration of ten indicators relevant for the two components of social marginalization: the material component and the symbolical component. The results highlighted a strong connection between the total degree of social marginalization and the dependence on social benefits, unemployment rate, non-inclusion in the compulsory education, criminality rate, and the type of pension insurance.
Keywords: Romania, social marginalization index, territorial disparities.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19481091 A Sociological Study of Rural Women Attitudes toward Education, Health and Work outside Home in Beheira Governorate, Egypt
Authors: A. A. Betah
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This research was performed to evaluate the attitudes of rural women towards education, health and work outside the home. The study was based on a random sample of 147 rural women, Kafr-Rahmaniyah village was chosen for the study because its life expectancy at birth for females, education and percentage of females in the labor force, were the highest in the district. The study data were collected from rural female respondents, using a face-to-face questionnaire. In addition, the study estimated several factors like age, main occupation, family size, monthly household income, geographic cosmopolites, and degree of social participation for rural women respondents. Using Statistical Package for the Social Sciences (SPSS), data were analyzed by non-parametric statistical methods. The main finding in this study was a significant relationship between each of the previous variables and each of rural women’s attitudes toward education, health, and work outside home. The study concluded with some recommendations. The most important element is ensuring attention to rural women’s needs, requirements and rights via raising their health awareness, education and their contributions in their society.Keywords: Attitudes, education, health, rural women, work outside the home.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10491090 Gender and Advertisements: A Content Analysis of Pakistani Prime Time Advertisements
Authors: Aaminah Hassan
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Advertisements carry a great potential to influence our lives because they are crafted to meet particular ends. Stereotypical representation in advertisements is capable of forming unconscious attitudes among people towards any gender and their abilities. This study focuses on gender representation in Pakistani prime time advertisements. For this purpose, 13 advertisements were selected from three different categories of foods and beverages, cosmetics, cell phones and cellular networks from the prime time slots of one of the leading Pakistani entertainment channel, ‘Urdu 1’. Both quantitative and qualitative analyses are carried out for range of variables like gender, age, roles, activities, setting, appearance and voice overs. The results revealed that gender representation in advertisements is stereotypical. Moreover, in few instances, the portrayal of women is not only culturally inappropriate but is demeaning to the image of women as well. Their bodily charm is used to promote products. Comparing different entertainment channels for their prime time advertisements and broadening the scope of this research will yield greater implications for the researchers who want to carry out the similar research. It is hoped that the current study would help in the promotion of media literacy among the viewers and media authorities in Pakistan.
Keywords: Advertisements, content analysis, gender, prime time.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10891089 Influence of Ammonium Concentration on the Performance of an Inorganic Biofilter Treating Methane
Authors: Marc Veillette, Antonio Avalos Ramirez, Michèle Heitz
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Among the technologies available to reduce methane emitted from the pig industry, biofiltration seems to be an effective and inexpensive solution. In methane (CH4) biofiltration, nitrogen is an important macronutrient for the microorganisms growth. The objective of this research project was to study the effect of ammonium (NH4 +) on the performance, the biomass production and the nitrogen conversion of a biofilter treating methane. For NH4 + concentrations ranging from 0.05 to 0.5 gN-NH4 +/L, the CH4 removal efficiency and the dioxide carbon production rate decreased linearly from 68 to 11.8 % and from 7.1 to 0.5 g/(m3-h), respectively. The dry biomass content varied from 4.1 to 5.8 kg/(m3 filter bed). For the same range of concentrations, the ammonium conversion decreased while the specific nitrate production rate increased. The specific nitrate production rate presented negative values indicating denitrification in the biofilter.Keywords: Methane, biofiltration, pig, ammonium, nitrification, denitrification.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16851088 Aerodynamics and Optimization of Airfoil Under Ground Effect
Authors: Kyoungwoo Park, Byeong Sam Kim, Juhee Lee, Kwang Soo Kim
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The Prediction of aerodynamic characteristics and shape optimization of airfoil under the ground effect have been carried out by integration of computational fluid dynamics and the multiobjective Pareto-based genetic algorithm. The main flow characteristics around an airfoil of WIG craft are lift force, lift-to-drag ratio and static height stability (H.S). However, they show a strong trade-off phenomenon so that it is not easy to satisfy the design requirements simultaneously. This difficulty can be resolved by the optimal design. The above mentioned three characteristics are chosen as the objective functions and NACA0015 airfoil is considered as a baseline model in the present study. The profile of airfoil is constructed by Bezier curves with fourteen control points and these control points are adopted as the design variables. For multi-objective optimization problems, the optimal solutions are not unique but a set of non-dominated optima and they are called Pareto frontiers or Pareto sets. As the results of optimization, forty numbers of non- dominated Pareto optima can be obtained at thirty evolutions.Keywords: Aerodynamics, Shape optimization, Airfoil on WIGcraft, Genetic algorithm, Computational fluid dynamics (CFD).
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 32171087 The Effectiveness of Bismuth Addition to Retard the Intermetallic Compound Formation
Authors: I. Siti Rabiatull Aisha, A. Ourdjini, O. Saliza Azlina
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The aim of this paper is to study the effectiveness of bismuth addition in the solder alloy to retard the intermetallic compound formation and growth. In this study, three categories of solders such as Sn-4Ag-xCu (x = 0.5, 0.7, 1.0) and Sn-4Ag-0.5Cu-xBi (x = 0.1, 0.2, 0.4) were used. Ni/Au surface finish substrates were dipped into the molten solder at a temperature of 180-190 oC and allowed to cool at room temperature. The intermetallic compound (IMCs) were subjected to the characterization in terms of composition and morphology. The IMC phases were identified by energy dispersive x-ray (EDX), whereas the optical microscope and scanning electron microscopy (SEM) were used to observe microstructure evolution of the solder joint. The results clearly showed that copper concentration dependency was high during the reflow stage. Besides, only Ni3Sn4 and Ni3Sn2 were detected for all copper concentrations. The addition of Bi was found to have no significant effect on the type of IMCs formed, but yet the grain became further refined.
Keywords: Bismuth addition, intermetallic compound, composition, morphology.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12991086 Kinetic Study of Gluconic Acid Batch Fermentation by Aspergillus niger
Authors: Akbarningrum Fatmawati, Rudy Agustriyanto, Lindawati
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Gluconic acid is one of interesting chemical products in industries such as detergents, leather, photographic, textile, and especially in food and pharmaceutical industries. Fermentation is an advantageous process to produce gluconic acid. Mathematical modeling is important in the design and operation of fermentation process. In fact, kinetic data must be available for modeling. The kinetic parameters of gluconic acid production by Aspergillus niger in batch culture was studied in this research at initial substrate concentration of 150, 200 and 250 g/l. The kinetic models used were logistic equation for growth, Luedeking-Piret equation for gluconic acid formation, and Luedeking-Piret-like equation for glucose consumption. The Kinetic parameters in the model were obtained by minimizing non linear least squares curve fitting.Keywords: Aspergillus niger, fermentation, gluconic acid, kinetic.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26851085 Production Throughput Modeling under Five Uncertain Variables Using Bayesian Inference
Authors: Amir Azizi, Amir Yazid B. Ali, Loh Wei Ping
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Throughput is an important measure of performance of production system. Analyzing and modeling of production throughput is complex in today-s dynamic production systems due to uncertainties of production system. The main reasons are that uncertainties are materialized when the production line faces changes in setup time, machinery break down, lead time of manufacturing, and scraps. Besides, demand changes are fluctuating from time to time for each product type. These uncertainties affect the production performance. This paper proposes Bayesian inference for throughput modeling under five production uncertainties. Bayesian model utilized prior distributions related to previous information about the uncertainties where likelihood distributions are associated to the observed data. Gibbs sampling algorithm as the robust procedure of Monte Carlo Markov chain was employed for sampling unknown parameters and estimating the posterior mean of uncertainties. The Bayesian model was validated with respect to convergence and efficiency of its outputs. The results presented that the proposed Bayesian models were capable to predict the production throughput with accuracy of 98.3%.
Keywords: Bayesian inference, Uncertainty modeling, Monte Carlo Markov chain, Gibbs sampling, Production throughput
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21361084 Efficient Tuning Parameter Selection by Cross-Validated Score in High Dimensional Models
Authors: Yoonsuh Jung
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As DNA microarray data contain relatively small sample size compared to the number of genes, high dimensional models are often employed. In high dimensional models, the selection of tuning parameter (or, penalty parameter) is often one of the crucial parts of the modeling. Cross-validation is one of the most common methods for the tuning parameter selection, which selects a parameter value with the smallest cross-validated score. However, selecting a single value as an ‘optimal’ value for the parameter can be very unstable due to the sampling variation since the sample sizes of microarray data are often small. Our approach is to choose multiple candidates of tuning parameter first, then average the candidates with different weights depending on their performance. The additional step of estimating the weights and averaging the candidates rarely increase the computational cost, while it can considerably improve the traditional cross-validation. We show that the selected value from the suggested methods often lead to stable parameter selection as well as improved detection of significant genetic variables compared to the tradition cross-validation via real data and simulated data sets.Keywords: Cross Validation, Parameter Averaging, Parameter Selection, Regularization Parameter Search.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15671083 Analyzing Preservice Teachers’ Attitudes towards Technology
Authors: Ahmet Oguz Akturk, Kemal Izci, Gurbuz Caliskan, Ismail Sahin
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Rapid developments in technology in the present age have made it necessary for communities to follow technological developments and adapt themselves to these developments. One of the fields that are most rapidly affected by these developments is undoubtedly education. Determination of the attitudes of preservice teachers, who live in an age of technology and get ready to raise future individuals, is of paramount importance both educationally and professionally. The purpose of this study was to analyze attitudes of preservice teachers towards technology and some variables that predict these attitudes (gender, daily duration of internet use, and the number of technical devices owned). 329 preservice teachers attending the education faculty of a large university in central Turkey participated, on a volunteer basis, in this study, where relational survey model was used as the research method. Research findings reveal that preservice teachers’ attitudes towards technology are positive and at the same time, the attitudes of male preservice teachers towards technology are more positive than their female counterparts. As a result of the stepwise multiple regression analysis where factors predicting preservice teachers’ attitudes towards technology, it was found that duration of daily internet use was the strongest predictor of attitudes towards technology.Keywords: Attitudes towards technology, preservice teachers, gender, stepwise multiple regression analysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17411082 A Study of Panel Logit Model and Adaptive Neuro-Fuzzy Inference System in the Prediction of Financial Distress Periods
Authors: Ε. Giovanis
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The purpose of this paper is to present two different approaches of financial distress pre-warning models appropriate for risk supervisors, investors and policy makers. We examine a sample of the financial institutions and electronic companies of Taiwan Security Exchange (TSE) market from 2002 through 2008. We present a binary logistic regression with paned data analysis. With the pooled binary logistic regression we build a model including more variables in the regression than with random effects, while the in-sample and out-sample forecasting performance is higher in random effects estimation than in pooled regression. On the other hand we estimate an Adaptive Neuro-Fuzzy Inference System (ANFIS) with Gaussian and Generalized Bell (Gbell) functions and we find that ANFIS outperforms significant Logit regressions in both in-sample and out-of-sample periods, indicating that ANFIS is a more appropriate tool for financial risk managers and for the economic policy makers in central banks and national statistical services.Keywords: ANFIS, Binary logistic regression, Financialdistress, Panel data
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23321081 Simulation of Natural Convection Flow in an Inclined open Cavity using Lattice Boltzmann Method
Authors: H. Sajjadi, M. Gorji, GH.R. Kefayati, D. D. Ganji, M. Shayan nia
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In this paper effects of inclination angle on natural convection flow in an open cavity has been analyzed with Lattice Boltzmann Method (LBM).The angle of inclination varied from θ= - 45° to 45° with 15° intervals. Study has been conducted for Rayleigh numbers (Ra) 104 to 106. The comparisons show that the average Nusselt number increases with growth of Rayleigh number and the average Nusselt number increase as inclination angles increases at Ra=104.At Ra=105 and Ra=106 the average Nusselt number enhance as inclination angels varied from θ= -45° to θ= 0° and decrease as inclination angels increase in θ= 0° to θ= 45°.Keywords: Lattice Boltzmann Method, Inclination angle, Opencavity, Natural convection
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19961080 Text Summarization for Oil and Gas Drilling Topic
Authors: Y. Y. Chen, O. M. Foong, S. P. Yong, Kurniawan Iwan
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Information sharing and gathering are important in the rapid advancement era of technology. The existence of WWW has caused rapid growth of information explosion. Readers are overloaded with too many lengthy text documents in which they are more interested in shorter versions. Oil and gas industry could not escape from this predicament. In this paper, we develop an Automated Text Summarization System known as AutoTextSumm to extract the salient points of oil and gas drilling articles by incorporating statistical approach, keywords identification, synonym words and sentence-s position. In this study, we have conducted interviews with Petroleum Engineering experts and English Language experts to identify the list of most commonly used keywords in the oil and gas drilling domain. The system performance of AutoTextSumm is evaluated using the formulae of precision, recall and F-score. Based on the experimental results, AutoTextSumm has produced satisfactory performance with F-score of 0.81.
Keywords: Keyword's probability, synonym sets.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17221079 Experimental and Numerical Investigations on Flexural Behavior of Macro-Synthetic FRC
Authors: Ashkan Shafee, Ahamd Fahimifar, Sajjad V. Maghvan
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Promotion of the Fiber Reinforced Concrete (FRC) as a construction material for civil engineering projects has invoked numerous researchers to investigate their mechanical behavior. Even though there is satisfactory information about the effects of fiber type and length, concrete mixture, casting type and other variables on the strength and deformability parameters of FRC, the numerical modeling of such materials still needs research attention. The focus of this study is to investigate the feasibility of Concrete Damaged Plasticity (CDP) model in prediction of Macro-synthetic FRC structures behavior. CDP model requires the tensile behavior of concrete to be well characterized. For this purpose, a series of uniaxial direct tension and four point bending tests were conducted on the notched specimens to define bilinear tension softening (post-peak tension stress-strain) behavior. With these parameters obtained, the flexural behavior of macro-synthetic FRC beams were modeled and the results showed a good agreement with the experimental measurements.
Keywords: Concrete damaged plasticity, fiber reinforced concrete, finite element modeling, macro-synthetic fibers, direct tensile test.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20671078 Effect of Herbicides on Narrow Leaved Weeds and Yield of Wheat (Triticum aestivum L.)
Authors: M. Yasin, A. Tanveer, Z. Iqbal, A. Ali
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This study was conducted to investigate the efficacy of five herbicides on narrow leaved weeds and growth and yield of wheat. An experiment was conducted at Agronomic Research Farm, University of Agriculture Faisalabad. The experiment was laid out in randomized complete block designee (RCBD) with three replications. Treatments studied were clodinafop (Topic-15 WG) at 37 g a.i. ha-1, clodinafop (Topaz-15 WG) at 45 g a.i. ha-1, fenoxaprop-p-ethyl (Puma Super-75 EW) at 45 g a.i. ha-1, fenoxaprop-p-ethyl (Gramicide-6.9 EW) at 85 g a.i. ha-1, fenoxaprop-p-ethyl (Chinlima-6.9 EW) at 85 g a.i. ha-1 and weedy check. Plots treated with fenoxaprop-p-ethyl (Puma Super-75 EW) at 45 g a.i. ha-1 produced relatively less weed biomass, more plant height, number of spike bearing tillers, number of grains per spike, 1000-grain weight and grain yield (4.20 t ha-1).Keywords: clodinafop, fenoxaprop-p-ethyl, weeds, wheat
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22631077 An Improved Performance of the SRM Drives Using Z-Source Inverter with the Simplified Fuzzy Logic Rule Base
Authors: M. Hari Prabhu
Abstract:
This paper is based on the performance of the Switched Reluctance Motor (SRM) drives using Z-Source Inverter with the simplified rule base of Fuzzy Logic Controller (FLC) with the output scaling factor (SF) self-tuning mechanism are proposed. The aim of this paper is to simplify the program complexity of the controller by reducing the number of fuzzy sets of the membership functions (MFs) without losing the system performance and stability via the adjustable controller gain. ZSI exhibits both voltage-buck and voltage-boost capability. It reduces line harmonics, improves reliability, and extends output voltage range. The output SF of the controller can be tuned continuously by a gain updating factor, whose value is derived from fuzzy logic, with the plant error and error change ratio as input variables. Then the results, carried out on a four-phase 6/8 pole SRM based on the dSPACEDS1104 platform, to show the feasibility and effectiveness of the devised methods and also performance of the proposed controllers will be compared with conventional counterpart.
Keywords: Fuzzy logic controller, scaling factor (SF), switched reluctance motor (SRM), variable-speed drives.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24151076 Characterization of Novel Atrazine-Degrading Klebsiella sp. isolated from Thai Agricultural Soil
Authors: Sawangjit Sopid
Abstract:
Atrazine, a herbicide widely used in sugarcane and corn production, is a frequently detected groundwater contaminant. An atrazine-degrading bacterium, strain KB02, was obtained from long-term atrazine-treated sugarcane field soils in Kanchanaburi province of Thailand. Strain KB02 had a rod-to-coccus morphological cycle during growth. Sequence analysis of the PCR product indicated that the 16S rRNA gene in strain KB02 was ranging from 97-98% identical to the same region in Klebsiella sp. Based on biochemical, physiological analysis and 16S rDNA sequence analysis of one representative isolate, strain KB02, the isolates belong to the genus Klebsiella in the family Enterobacteriaceae. Interestingly that the various primers for atzA, B and C failed to amplify genomic DNA of strain KB02. Whereas the expected PCR product of atzA, B and C were obtained from the reference strain, Arthrobacter sp. strain KU001.
Keywords: Atrazine, atz gene, Biodegradation, bioremediation, Klebsiella
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19411075 Effects of Oilfield Water Treated by Electroflocculation and Reverse Osmosis in a Typical Brazilian Semiarid Soil
Authors: P. S. A. Souza, M. R. C. Marques, M. M. Rigo, A. A. Cerqueira, J. L. Paiva, F. Merçon, D. V. Perez
Abstract:
Produced water (PW), which is water extracted along with oil, is the largest waste stream in the oil and gas industry. With the proper treatment, this wastewater can be used in agricultural irrigation. This study evaluated the effects the application of PW treated by electroflocculation (EF) and combined electroflocculation-reverse osmosis (EF-RO) on soil salinity and sodification parameters. Excessive sodium levels in PW treated by EF may affect soil structural stability and plant growth, and tends to accumulate in upper layers, displacing the nutrient K to deeper layers of the soil profile. PW treated by EF-RO did not promote salinization and soil sodification, indicating that this combined technique may be a viable alternative for oily water treatment aiming at irrigation use in semiarid regions.
Keywords: Electroflocculation, irrigation, produced water, reverse osmosis, soil.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 576