Search results for: Sliding Mode Control (SMC)
1002 Thermo-Elastic Properties of Artificial Limestone Bricks with Wood Sawdust
Authors: Paki Turgut, Mehmet Gumuscu
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In this study, artificial limestone brick samples are produced by using wood sawdust wastes (WSW) having different grades of sizes and limestone powder waste (LPW). The thermo-elastic properties of produced brick samples in various WSW amounts are investigated. At 30% WSW replacement with LPW in the brick sample the thermal conductivity value is effectively reduced and the reduction in the thermal conductivity value of brick sample at 30% WSW replacement with LPW is about 38.9% as compared with control sample. The energy conservation in buildings by using LPW and WSW in masonry brick material production having low thermal conductivity reduces energy requirements. A strong relationship is also found among the thermal conductivity, unit weight and ultrasonic pulse velocity values of brick samples produced. It shows a potential to be used for walls, wooden board substitute, alternative to the concrete blocks, ceiling panels, sound barrier panels, absorption materials etc.
Keywords: Limestone dust, masonry brick, thermo-elastic properties, wood sawdust.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24951001 Optimization of Material Removal Rate in Electrical Discharge Machining Using Fuzzy Logic
Authors: Amit Kohli, Aashim Wadhwa, Tapan Virmani, Ujjwal Jain
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The objective of present work is to stimulate the machining of material by electrical discharge machining (EDM) to give effect of input parameters like discharge current (Ip), pulse on time (Ton), pulse off time (Toff) which can bring about changes in the output parameter, i.e. material removal rate. Experimental data was gathered from die sinking EDM process using copper electrode and Medium Carbon Steel (AISI 1040) as work-piece. The rules of membership function (MF) and the degree of closeness to the optimum value of the MMR are within the upper and lower range of the process parameters. It was found that proposed fuzzy model is in close agreement with the experimental results. By Intelligent, model based design and control of EDM process parameters in this study will help to enable dramatically decreased product and process development cycle times.Keywords: Electrical discharge Machining (EDM), Fuzzy Logic, Material removal rate (MRR), Membership functions (MF).
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 27541000 Trajectory-Based Modified Policy Iteration
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This paper presents a new problem solving approach that is able to generate optimal policy solution for finite-state stochastic sequential decision-making problems with high data efficiency. The proposed algorithm iteratively builds and improves an approximate Markov Decision Process (MDP) model along with cost-to-go value approximates by generating finite length trajectories through the state-space. The approach creates a synergy between an approximate evolving model and approximate cost-to-go values to produce a sequence of improving policies finally converging to the optimal policy through an intelligent and structured search of the policy space. The approach modifies the policy update step of the policy iteration so as to result in a speedy and stable convergence to the optimal policy. We apply the algorithm to a non-holonomic mobile robot control problem and compare its performance with other Reinforcement Learning (RL) approaches, e.g., a) Q-learning, b) Watkins Q(λ), c) SARSA(λ).Keywords: Markov Decision Process (MDP), Mobile robot, Policy iteration, Simulation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1447999 Using “Eckel” Model to Measure Income Smoothing Practices: The Case of French Companies
Authors: Feddaoui Amina
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Income smoothing represents an attempt on the part of the company's management to reduce variations in earnings through the manipulation of the accounting principles. In this study, we aimed to measure income smoothing practices in a sample of 30 French joint stock companies during the period (2007-2009), we used Dummy variables method and “ECKEL” model to measure income smoothing practices and Binomial test accourding to SPSS program, to confirm or refute our hypothesis. This study concluded that there are no significant statistical indicators of income smoothing practices in the sample studied of French companies during the period (2007-2009), so the income series in the same sample studied of is characterized by stability and non-volatility without any intervention of management through accounting manipulation. However, this type of accounting manipulation should be taken into account and efforts should be made by control bodies to apply Eckel model and generalize its use at the global level.
Keywords: Income, smoothing, “Eckel”, French companies.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1008998 A Critical Review on the Development of a Theoretical Framework for Managing Environmental Impacts of Construction Project
Authors: Sami Mustafa M. E. Ahmed, Noor Amila Wan Abdullah Zawawi, Zulkipli B. Ghazali
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Construction industry is considered as one of the main contributor of natural resources depletion, responsible for high level pollution and it is one of the attributes that pose climate changes and other environmental threats. A lot of efforts had and have been done to reduce and control these impacts. Project Environmental Management (PEM) includes the processes required to ensure that the impacts of the project execution to the surrounding environment will remain within the limits stated in legal permits. The main aim of most of researches conducted managing Environmental Impacts (EI) is to protect earth planet from pollution. Those researches are presenting four major environmental elements; Environmental Management Systems (EMS), Environmental Design (ED), Environmental Planning (EP) and Environmental Impacts Assessments (EIA). Although everything has been said about environmental management for construction projects, but almost everything remains to be said and therefore to be explored or rediscovered because incontestably, almost everything remains to be done. This paper aimed at reviewing some of what has been said about PEM. Also one of its objectives is to explore and rediscover the whole view of managing the EI problems by proposing a framework that based on the relation between these environmental researches.
Keywords: Environmental planning, sustainable design, EIA and EMS.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2425997 A Block Cipher for Resource-Constrained IoT Devices
Authors: Muhammad Rana, Quazi Mamun, Rafiqul Islam
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In the Internet of Things (IoT), many devices are connected and accumulate a sheer amount of data. These Internet-driven raw data need to be transferred securely to the end-users via dependable networks. Consequently, the challenges of IoT security in various IoT domains are paramount. Cryptography is being applied to secure the networks for authentication, confidentiality, data integrity and access control. However, due to the resource constraint properties of IoT devices, the conventional cipher may not be suitable in all IoT networks. This paper designs a robust and effective lightweight cipher to secure the IoT environment and meet the resource-constrained nature of IoT devices. We also propose a symmetric and block-cipher based lightweight cryptographic algorithm. The proposed algorithm increases the complexity of the block cipher, maintaining the lowest computational requirements possible. The proposed algorithm efficiently constructs the key register updating technique, reduces the number of encryption rounds, and adds a layer between the encryption and decryption processes.
Keywords: Internet of Things, IoT, cryptography block cipher, s-box, key management, IoT security.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 552996 Design of Gain Scheduled Fuzzy PID Controller
Authors: Leehter Yao, Chin-Chin Lin
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An adaptive fuzzy PID controller with gain scheduling is proposed in this paper. The structure of the proposed gain scheduled fuzzy PID (GS_FPID) controller consists of both fuzzy PI-like controller and fuzzy PD-like controller. Both of fuzzy PI-like and PD-like controllers are weighted through adaptive gain scheduling, which are also determined by fuzzy logic inference. A modified genetic algorithm called accumulated genetic algorithm is designed to learn the parameters of fuzzy inference system. In order to learn the number of fuzzy rules required for the TSK model, the fuzzy rules are learned in an accumulated way. In other words, the parameters learned in the previous rules are accumulated and updated along with the parameters in the current rule. It will be shown that the proposed GS_FPID controllers learned by the accumulated GA perform well for not only the regular linear systems but also the higher order and time-delayed systems.
Keywords: Gain scheduling, fuzzy PID controller, adaptive control, genetic algorithm.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 4075995 Parenting Styles and Their Relation to Videogame Addiction
Authors: Petr Květon, Martin Jelínek
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We try to identify the role of various aspects of parenting style in the phenomenon of videogame playing addiction. Relevant self-report questionnaires were part of a wider set of methods focused on the constructs related to videogame playing. The battery of methods was administered in school settings in paper and pencil form. The research sample consisted of 333 (166 males, 167 females) elementary and high school students at the age between 10 and 19 years (m=14.98, sd=1.77). Using stepwise regression analysis, we assessed the influence of demographic variables (gender and age) and parenting styles. Age and gender together explained 26.3% of game addiction variance (F(2,330)=58.81, p<.01). By adding four aspect of parenting styles (inconsistency, involvement, control, and warmth) another 10.2% of variance was explained (∆F(4,326)=13.09, p<.01). The significant predictor was gender of the respondent, where males scored higher on game addiction scale (B=0.70, p<.01), age (β=-0.18, p<.01), where younger children showed higher level of addiction, and parental inconsistency (β=0.30, p<.01), where the higher the inconsistency in upbringing, the more developed game playing addiction.
Keywords: Gender, parenting styles, video games, addiction.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2753994 Eco-Friendly Preservative Treated Bamboo Culm: Compressive Strength Analysis
Authors: Perminder JitKaur, Santosh Satya, K. K. Pant, S. N. Naik
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Bamboo is extensively used in construction industry. Low durability of bamboo due to fungus infestation and termites attack under storage puts certain constrains for it usage as modern structural material. Looking at many chemical formulations for bamboo treatment leading to severe harmful environment effects, research on eco-friendly preservatives for bamboo treatment has been initiated world-over. In the present studies, eco-friendly preservative for bamboo treatment has been developed. To validate its application for structural purposes, investigation of effect of treatment on compressive strength has been investigated. Neemoil (25%) integrated with copper naphthenate (0.3%) on dilution with kerosene oil impregnated into bamboo culm at 2 bar pressure, has shown weight loss of only 3.15% in soil block analysis method. The results from compressive strength analysis using HEICO Automatic Compression Testing Machine reveal that preservative treatment has not altered the structural properties of bamboo culms. Compressive strength of control (11.72 N/mm2) and above treated samples (11.71 N/mm2) was found to be comparable.
Keywords: Compressive strength, D. strictus bamboo, Ecofriendly treatment, neem oil.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3449993 Is the Liberalization Policy Effective on Improving the Bivariate Cointegration of Current Accounts, Foreign Exchange, Stock Prices? Further Evidence from Asian Markets
Authors: Chen-Yin Kuo
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This paper fist examines three set of bivariate cointegrations between any two of current accounts, stock markets, and currency exchange markets in ten Asian countries. Furthermore, we examined the effect of country characters on this bivariate cointegration. Our findings suggest that for three sets of cointegration test, each sample country at least exists one cointegration. India consistently exhibited a bi-directional causal relationship between any two of three indicators. Unlike Pan et al. (2007) and Phylaktis and Ravazzolo (2005), we found that such cointegration is influenced by three characteristics: capital control; flexibility in foreign exchange rates; and the ratio of trade to GDP. These characteristics are the result of liberalization in each Asian country. This implies that liberalization policies are effective on improving the cointegration between any two of financial markets and current account for ten Asian countries.
Keywords: Current account, stock price, foreign exchange rate, country characteristics, bivariate cointegration, bi-directional causal relationships.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1473992 Case Study on Innovative Aquatic-Based Bioeconomy for Chlorella sorokiniana
Authors: Iryna Atamaniuk, Hannah Boysen, Nils Wieczorek, Natalia Politaeva, Iuliia Bazarnova, Kerstin Kuchta
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Over the last decade due to climate change and a strategy of natural resources preservation, the interest for the aquatic biomass has dramatically increased. Along with mitigation of the environmental pressure and connection of waste streams (including CO2 and heat emissions), microalgae bioeconomy can supply food, feed, as well as the pharmaceutical and power industry with number of value-added products. Furthermore, in comparison to conventional biomass, microalgae can be cultivated in wide range of conditions without compromising food and feed production, thus addressing issues associated with negative social and the environmental impacts. This paper presents the state-of-the art technology for microalgae bioeconomy from cultivation process to production of valuable components and by-streams. Microalgae Chlorella sorokiniana were cultivated in the pilot-scale innovation concept in Hamburg (Germany) using different systems such as race way pond (5000 L) and flat panel reactors (8 x 180 L). In order to achieve the optimum growth conditions along with suitable cellular composition for the further extraction of the value-added components, process parameters such as light intensity, temperature and pH are continuously being monitored. On the other hand, metabolic needs in nutrients were provided by addition of micro- and macro-nutrients into a medium to ensure autotrophic growth conditions of microalgae. The cultivation was further followed by downstream process and extraction of lipids, proteins and saccharides. Lipids extraction is conducted in repeated-batch semi-automatic mode using hot extraction method according to Randall. As solvents hexane and ethanol are used at different ratio of 9:1 and 1:9, respectively. Depending on cell disruption method along with solvents ratio, the total lipids content showed significant variations between 8.1% and 13.9 %. The highest percentage of extracted biomass was reached with a sample pretreated with microwave digestion using 90% of hexane and 10% of ethanol as solvents. Proteins content in microalgae was determined by two different methods, namely: Total Kejadahl Nitrogen (TKN), which further was converted to protein content, as well as Bradford method using Brilliant Blue G-250 dye. Obtained results, showed a good correlation between both methods with protein content being in the range of 39.8–47.1%. Characterization of neutral and acid saccharides from microalgae was conducted by phenol-sulfuric acid method at two wavelengths of 480 nm and 490 nm. The average concentration of neutral and acid saccharides under the optimal cultivation conditions was 19.5% and 26.1%, respectively. Subsequently, biomass residues are used as substrate for anaerobic digestion on the laboratory-scale. The methane concentration, which was measured on the daily bases, showed some variations for different samples after extraction steps but was in the range between 48% and 55%. CO2 which is formed during the fermentation process and after the combustion in the Combined Heat and Power unit can potentially be used within the cultivation process as a carbon source for the photoautotrophic synthesis of biomass.Keywords: Bioeconomy, lipids, microalgae, proteins, saccharides.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 906991 A Floating Gate MOSFET Based Novel Programmable Current Reference
Authors: V. Suresh Babu, Haseena P. S., Varun P. Gopi, M. R. Baiju
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In this paper a scheme is proposed for generating a programmable current reference which can be implemented in the CMOS technology. The current can be varied over a wide range by changing an external voltage applied to one of the control gates of FGMOS (Floating Gate MOSFET). For a range of supply voltages and temperature, CMOS current reference is found to be dependent, this dependence is compensated by subtracting two current outputs with the same dependencies on the supply voltage and temperature. The system performance is found to improve with the use of FGMOS. Mathematical analysis of the proposed circuit is done to establish supply voltage and temperature independence. Simulation and performance evaluation of the proposed current reference circuit is done using TANNER EDA Tools. The current reference shows the supply and temperature dependencies of 520 ppm/V and 312 ppm/oC, respectively. The proposed current reference can operate down to 0.9 V supply.
Keywords: Floating Gate MOSFET, current reference, self bias scheme, temperature independency, supply voltage independency.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1805990 Comparison of Conventional and “ECO“Transportation Pavements in Cyprus using Life Cycle Approach
Authors: Constantia Achilleos, Diofantos G. Hadjimitsis
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Road industry has challenged the prospect of ecoconstruction. Pavements may fit within the framework of sustainable development. Hence, research implements assessments of conventional pavements impacts on environment in use of life cycle approach. To meet global, and often national, targets on pollution control, newly introduced pavement designs are under study. This is the case of Cyprus demonstration, which occurred within EcoLanes project work. This alternative pavement differs on concrete layer reinforced with tire recycling product. Processing of post-consumer tires produces steel fibers improving strength capacity against cracking. Thus maintenance works are relevantly limited in comparison to flexible pavement. This enables to be more ecofriendly, referenced to current study outputs. More specific, proposed concrete pavement life cycle processes emits 15 % less air pollutants and consumes 28 % less embodied energy than those of the asphalt pavement. In addition there is also a reduction on costs by 0.06 %.
Keywords: Environmental impact assessment, life cycle, tirerecycling, transportation pavement.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2186989 Simulator Dynamic Positioning System with Azimuthal Thruster
Authors: Robson C. Santos, Christian N. Barreto, Gerson G. Cunha, Severino J. C. Neto
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This paper aims to project the construction of a prototype azimuthal thruster, mounted with materials of low cost and easy access, testing in a controlled environment to measure their performance, characteristics and feasibility of future projects. The construction of the simulation of dynamic positioning software, responsible for simulating a vessel and reposition it when necessary. Validation tests were performed in the form of partial or complete system. These tests validate the system manually or automatically. The system provides an interface to the user and simulates the conditions unfavorable positioning of a vessel, accurately calculates the azimuth angle, the direction of rotation of the helix and the time that this should be turned on so that the vessel back to position original. A serial communication connects the Simulation Dynamic Positioning System with Embedded System causing the usergenerated data to simulate the DP system arrives in the form of control signals to the motors of the propellant. This article addresses issues in the marine industry employees.Keywords: Azimuthal Thruster, Dynamic Positioning, Embedded System.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2780988 Determination of Some Biochemical Parameters in Women during the First Trimester of Pregnancy (Normal Pregnancy and Missed Miscarriage)
Authors: Yahia M., Chaoui N., Chaouch A., Massinissa Yahia
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Our study was designed to determine the metabolic changes of some biochemical parameters (cholesterol, triglyceride, Iron, uric acid, Urea and folic acid) and highlight their changes in 57 women of the region Batna, during the first trimester of pregnancy. This practical work was done with 27 women with missed miscarriage, compared with 30 control subjects of normal pregnant women. The assay results revealed a highly significant difference (P = 0.0006) between the two groups in serum iron (64.00 vs 93.54) and in the rate of folate (6.70 vs 9.22) (P <0.001) but no difference was found regarding the rate of Ca (9.69 vs 10.20), urea (0.19 vs 0.17), UA (33.96 vs 32.76), CH (1.283 vs 1.431), and TG (0.8852 vs 0.8290). The present study indicates that iron deficiency and folate are associated with missed miscarriage, but no direct pathophysiological link has been determined. Further in-depth studies are needed to determine the exact mechanism by which these deficits lead to a missed miscarriage.
Keywords: Biochemical parameters, pregnant women, missed miscarriage.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2155987 Genetic Algorithms for Feature Generation in the Context of Audio Classification
Authors: José A. Menezes, Giordano Cabral, Bruno T. Gomes
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Choosing good features is an essential part of machine learning. Recent techniques aim to automate this process. For instance, feature learning intends to learn the transformation of raw data into a useful representation to machine learning tasks. In automatic audio classification tasks, this is interesting since the audio, usually complex information, needs to be transformed into a computationally convenient input to process. Another technique tries to generate features by searching a feature space. Genetic algorithms, for instance, have being used to generate audio features by combining or modifying them. We find this approach particularly interesting and, despite the undeniable advances of feature learning approaches, we wanted to take a step forward in the use of genetic algorithms to find audio features, combining them with more conventional methods, like PCA, and inserting search control mechanisms, such as constraints over a confusion matrix. This work presents the results obtained on particular audio classification problems.
Keywords: Feature generation, feature learning, genetic algorithm, music information retrieval.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1084986 Blinking Characteristics and Corneal Staining in Different Soft Lens Materials
Authors: Bashirah Ishak, Jacyln JiaYing Thye, Bariah Mohd Ali, Norhani Mohidin
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Background Contact lens (CL) wear can cause changes in blinking and corneal staining. Aims and Objectives To determine the effects of CL materials (HEMA and SiHy) on spontaneous blink rate, blinking patterns and corneal staining after 2 months of wear. Methods Ninety subjects in 3 groups (control, HEMA and SiHy) were assessed at baseline and 2-months. Blink rate was recorded using a video camera. Blinking patterns were assessed with digital camera and slit lamp biomicroscope. Corneal staining was graded using IER grading scale Results There were no significant differences in all parameters at baseline. At 2 months, CL wearers showed significant increment in average blink rate (F1.626, 47.141 = 7.250, p = 0.003; F2,58 = 6.240, p = 0.004) and corneal staining (χ2 2, n=30 = 31.921, p < 0.001; χ2 2, n=30 = 26.909, p < 0.001). Conclusion Blinking characteristics and corneal staining were not influence by soft CL materials.Keywords: Spontaneous blinking, cornea staining, grading, soft contact lenses.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2400985 Theoretical Investigation on the Dynamic Characteristics of One Degree of Freedom Vibration System Equipped with Inerter of Variable Inertance
Authors: Barenten Suciu, Yoshiki Tsuji
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In this paper, a theoretical investigation on the dynamic characteristics of one degree of freedom vibration system equipped with inerter of variable inertance, is presented. Differential equation of movement was solved under proper initial conditions in the case of free undamped/damped vibration, considered in the absence/presence of the inerter in the mechanical system. Influence of inertance on the amplitude of vibration, phase angle, natural frequency, damping ratio, and logarithmic decrement was clarified. It was mainly found that the inerter decreases the natural frequency of the undamped system and also of the damped system if the damping ratio is below 0.707. On the other hand, the inerter increases the natural frequency of the damped system if the damping ratio exceeds 0.707. Results obtained in this work are useful for the adequate design of inerters.
Keywords: One degree of freedom vibration system, inerter, parallel connection, variable inertance, frequency control, damping.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1645984 Intelligent Maximum Power Point Tracking Using Fuzzy Logic for Solar Photovoltaic Systems Under Non-Uniform Irradiation Conditions
Authors: P. Selvam, S. Senthil Kumar
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Maximum Power Point Tracking (MPPT) has played a vital role to enhance the efficiency of solar photovoltaic (PV) power generation under varying atmospheric temperature and solar irradiation. However, it is hard to track the maximum power point using conventional linear controllers due to the natural inheritance of nonlinear I-V and P-V characteristics of solar PV systems. Fuzzy Logic Controller (FLC) is suitable for nonlinear system control applications and eliminating oscillations, circuit complexities present in the conventional perturb and observation and incremental conductance methods respectively. Hence, in this paper, FLC is proposed for tracking exact MPPT of solar PV power generation system under varying solar irradiation conditions. The effectiveness of the proposed FLC-based MPPT controller is validated through simulation and analysis using MATLAB/Simulink.
Keywords: Fuzzy logic controller, maximum power point tracking, photovoltaic.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1591983 A New Approach for Network Reconfiguration Problem in Order to Deviation Bus Voltage Minimization with Regard to Probabilistic Load Model and DGs
Authors: Mahmood Reza Shakarami, Reza Sedaghati
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Recently, distributed generation technologies have received much attention for the potential energy savings and reliability assurances that might be achieved as a result of their widespread adoption. The distribution feeder reconfiguration (DFR) is one of the most important control schemes in the distribution networks, which can be affected by DGs. This paper presents a new approach to DFR at the distribution networks considering wind turbines. The main objective of the DFR is to minimize the deviation of the bus voltage. Since the DFR is a nonlinear optimization problem, we apply the Adaptive Modified Firefly Optimization (AMFO) approach to solve it. As a result of the conflicting behavior of the single- objective function, a fuzzy based clustering technique is employed to reach the set of optimal solutions called Pareto solutions. The approach is tested on the IEEE 32-bus standard test system.
Keywords: Adaptive Modified Firefly Optimization (AMFO), Pareto solutions, feeder reconfiguration, wind turbines, bus voltage.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2020982 A Single Phase ZVT-ZCT Power Factor Correction Boost Converter
Authors: Yakup Sahin, Naim Suleyman Ting, Ismail Aksoy
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In this paper, a single phase soft switched Zero Voltage Transition and Zero Current Transition (ZVT-ZCT) Power Factor Correction (PFC) boost converter is proposed. In the proposed PFC converter, the main switch turns on with ZVT and turns off with ZCT without any additional voltage or current stresses. Auxiliary switch turns on and off with zero current switching (ZCS). Also, the main diode turns on with zero voltage switching (ZVS) and turns off with ZCS. The proposed converter has features like low cost, simple control and structure. The output current and voltage are controlled by the proposed PFC converter in wide line and load range. The theoretical analysis of converter is clarified and the operating steps are given in detail. The simulation results of converter are obtained for 500 W and 100 kHz. It is observed that the semiconductor devices operate with soft switching (SS) perfectly. So, the switching power losses are minimum. Also, the proposed converter has 0.99 power factor with sinusoidal current shape.Keywords: Power factor correction, zero-voltage transition, zero-current transition, soft switching.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2011981 Entropy Generation Analyze Due to the Steady Natural Convection of Newtonian Fluid in a Square Enclosure
Authors: T. T. Naas, Y. Lasbet, C. Kezrane
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The thermal control in many systems is widely accomplished applying mixed convection process due to its low cost, reliability and easy maintenance. Typical applications include the aircraft electronic equipment, rotating-disc heat exchangers, turbo machinery, and nuclear reactors, etc. Natural convection in an inclined square enclosure heated via wall heater has been studied numerically. Finite volume method is used for solving momentum and energy equations in the form of stream function–vorticity. The right and left walls are kept at a constant temperature, while the other parts are adiabatic. The range of the inclination angle covers a whole revolution. The method is validated for a vertical cavity. A general power law dependence of the Nusselt number with respect to the Rayleigh number with the coefficient and exponent as functions of the inclination angle is presented. For a fixed Rayleigh number, the inclination angle increases or decreases is found.
Keywords: Inclined enclosure, natural convection in enclosure, Nusselt number.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2231980 Effect of Capsule Storage on Viability of Lactobacillus bulgaricus and Streptococcus thermophilus in Yogurt Powder
Authors: Kanchana Sitlaothaworn
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Yogurt capsule was made by mixing 14% w/v of reconstitution of skim milk with 2% FOS. The mixture was fermented by commercial yogurt starter comprising Lactobacillus bulgaricus and Streptococcus thermophilus. These yogurts were made as yogurt powder by freeze-dried. Yogurt powder was put into capsule then stored for 28 days at 4oc. 8ml of commercial yogurt was found to be the most suitable inoculum size in yogurt production. After freeze-dried, the viability of L. bulgaricus and S. thermophilus reduced from 109 to 107 cfu/g. The precence of sucrose cannot help to protect cell from ice crystal formation in freeze-dried process, high (20%) sucrose reduced L. bulgaricus and S. thermophilus growth during fermentation of yogurt. The addition of FOS had reduced slowly the viability of both L. bulgaricus and S. thermophilus similar to control (without FOS) during 28 days of capsule storage. The viable cell exhibited satisfactory viability level in capsule storage (6.7x106cfu/g) during 21 days at 4oC.Keywords: Yogurt capsule, Lactobacillus bulgaricus, Streptococcus thermophilus, freeze-drying, sucrose.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1394979 Sensitivity Analysis for Determining Priority of Factors Controlling SOC Content in Semiarid Condition of West of Iran
Authors: Y. Parvizi, M. Gorji, M.H. Mahdian, M. Omid
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Soil organic carbon (SOC) plays a key role in soil fertility, hydrology, contaminants control and acts as a sink or source of terrestrial carbon content that can affect the concentration of atmospheric CO2. SOC supports the sustainability and quality of ecosystems, especially in semi-arid region. This study was conducted to determine relative importance of 13 different exploratory climatic, soil and geometric factors on the SOC contents in one of the semiarid watershed zones in Iran. Two methods canonical discriminate analysis (CDA) and feed-forward back propagation neural networks were used to predict SOC. Stepwise regression and sensitivity analysis were performed to identify relative importance of exploratory variables. Results from sensitivity analysis showed that 7-2-1 neural networks and 5 inputs in CDA models output have highest predictive ability that explains %70 and %65 of SOC variability. Since neural network models outperformed CDA model, it should be preferred for estimating SOC.Keywords: Soil organic carbon, modeling, neural networks, CDA.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1439978 Weigh-in-Motion Data Analysis Software for Developing Traffic Data for Mechanistic Empirical Pavement Design
Authors: M. A. Hasan, M. R. Islam, R. A. Tarefder
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Currently, there are few user friendly Weigh-in- Motion (WIM) data analysis softwares available which can produce traffic input data for the recently developed AASHTOWare pavement Mechanistic-Empirical (ME) design software. However, these softwares have only rudimentary Quality Control (QC) processes. Therefore, they cannot properly deal with erroneous WIM data. As the pavement performance is highly sensible to the quality of WIM data, it is highly recommended to use more refined QC process on raw WIM data to get a good result. This study develops a userfriendly software, which can produce traffic input for the ME design software. This software takes the raw data (Class and Weight data) collected from the WIM station and processes it with a sophisticated QC procedure. Traffic data such as traffic volume, traffic distribution, axle load spectra, etc. can be obtained from this software; which can directly be used in the ME design software.Keywords: Weigh-in-motion, software, axle load spectra, traffic distribution, AASHTOWare.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1899977 The Effect of Goat Milk Fractions Supplementation on Serum IgE Response and Leukocytes Count in Dinitrochlorobenzene Sensitized Rat
Authors: Nurliyani, E. Harmayani, MHNE. Soesatyo
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In Indonesia, goat milk is often consumed and believed as anti-allergy. The objective of this research was to study the effect of goat milk and their fractions (casein and whey) supplementation on total serum IgE concentrations and leukocytes count in rat sensitized with contact allergen dinitrochlorobenzene (DNCB). Female Wistar rats 6-8 weeks old were divided into four groups: 1) whey, 2) casein, 3) whole milk supplementation and 4) phosphate-buffered saline/PBS (control). The results showed that supplementation of goat milk on rats did not affects on total serum IgE concentrations and number of leukocytes. After sensitized with DNCB, the monocyte percentage in rats was higher (P<0.01) than before. In conclusion, goat milk or their fractions supplementation unable to decrease the total serum IgE concentrations and also had no effect on leukocytes count. However, 1% DNCB could increase the number of monocytes, but could not induce the IgE response.Keywords: Dinitrochlorobenzene, Goat Milk Fractions, IgE, Leukocytes.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1589976 Laser Doppler Flowmetry in Diagnostics of Vascular Lesions in Lower Extremities
Authors: Petr V. Vasilev, Eduard V. Volkov, Alexej N. Godok, Alexej A, Grischschuk, Vitalij A. Rybalchenko
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Laser Doppler flowmetry is a modern method of noninvasive microcirculation investigation. The aim of our study was to use this method in the examination of patients with secondary lymphedema of the lower extremities and obliterating atherosclerosis of lower extremities. In the analysis of the amplitude-frequency spectrum of secondary lymphedema patients we have identified remarkable changes. To describe the changes we used a special amplitude rate. In both of patients groups this rate was significally (p<0.05) different with the control group. So the marker phenomena of the amplitude-frequency spectrum of the LDF signal were identified. It is suggested that there is a limfodynamics contribution to the formation of the output signal of laser Doppler flowmetry. These data have fundamental meaning and are interesting for practical medicine, as they give an opportunity to further developments for the use of laser Doppler flowmetry in the diagnostics and monitoring the effectiveness of the treatment.Keywords: laser Doppler flowmetry, secondary lymphedema of the lower extremities, obliterating atherosclerosis, non-invasive diagnostics.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1736975 The Effectiveness of ICT-Assisted PBL on College-Level Nano Knowledge and Learning Skills
Authors: Ya-Ting Carolyn Yang, Ping-Han Cheng, Shi-Hui Gilbert Chang, Terry Yuan-Fang Chen, Chih-Chieh Li
Abstract:
Nanotechnology is widely applied in various areas so professionals in the related fields have to know more than nano knowledge. In the study, we focus on adopting ICT-assisted PBL in college general education to foster professionals who possess multiple abilities. The research adopted a pretest and posttest quasi-experimental design. The control group received traditional instruction, and the experimental group received ICT-assisted PBL instruction. Descriptive statistics will be used to describe the means, standard deviations, and adjusted means for the tests between the two groups. Next, analysis of covariance (ANCOVA) will be used to compare the final results of the two research groups after 6 weeks of instruction. Statistics gathered in the end of the research can be used to make contrasts. Therefore, we will see how different teaching strategies can improve students’ understanding about nanotechnology and learning skills.
Keywords: Nanotechnology, science education, project-based learning, information and communication technology.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2081974 Evaluation of South African Plants with Acaricide Activity against Ticks
Authors: G. Fouché, J. N. Eloff, K. Wellington
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Acaricides are commonly used to control ticks but are toxic, harmful to the environment and too expensive to resource-limited farmers. Traditionally, many communities in South Africa rely on a wide range of indigenous practices to keep their livestock healthy. One of these health care practices includes the use of medicinal plants and this offers an alternative to conventional medicine. An investigation was conducted at the CSIR in South Africa, and selected indigenous plants used in communities were scientifically evaluated for the management of ticks in animals. 17 plants were selected from 239 plants used traditionally in South Africa. Two different organic extracts were prepared from the 17 samples, resulting in 34 plant samples. These were tested for efficacy against two tick species, namely Rhipicephalus microplus and Rhipicephalus turanicus. The plant extracts were also screened against Vero cells and most were found to have low cytotoxicity. This study has shown that there is potential for the development of botanicals as natural acaricides against ticks that are non-toxic and environmentally benign.
Keywords: Rhipicephalus microplus, Rhipicephalus turanicus, ticks, plant extracts, South Africa.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1227973 Separation Characteristics of Dissolved Gases from Water Concurrently Variable Mixed with Exhalations for the Hollow Fiber Membrane
Authors: Pil Woo Heo
Abstract:
Water contains dissolved oxygen that a fish needs to breathe. It is important to increase the amounts of separation of dissolved oxygen from water for diverse applications using the separation system. In this paper, a separation system of dissolved gases from water concurrently variable mixed with the exhalations using a compressor is proposed. This system takes use of exhalations to increase the amounts of separation of dissolved oxygen from water. A compressor with variable off-time and on-time is used to control the exhalations mixed with inlet water. Exhalations contain some portion of carbon dioxide, oxygen, and nitrogen. Separation of dissolved gases containing dissolved oxygen is enhanced by using exhalations. The amounts of separation and the compositions of carbon dioxide and oxygen are measured. Higher amounts of separation can make the size of the separation device smaller, and then, application areas are diversified.
Keywords: Concurrently, variable mixed, exhalations, separation, hollow fiber.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1112