Search results for: SPICE model
6720 Developing a Mathematical Model for Trade-off Analysis of New Green Products
Authors: M. R. Gholizadeh, N. Bhuiyan, M. Salari
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In the near future, companies will be increasingly forced to shift their activities along a new road in order to decrease the harmful effects of their design, production and after-life on our environment. Products must meet environmental standards to not only prevent penalties but to consider the sustainability for future generations. However, the most important factor that companies will face is selecting a reasonable strategy to maximize their profit. Thus, companies need to have precise forecast from their profit after design stage through Trade-off analysis. This paper is an attempt to introduce a mathematical model that considers effective factors that impact the total profit when products are designed for resource and energy efficiency or recyclability. The modification is according to different strategies based on a Cost-Volume-Profit model. Here, the cost structure consists of Recycling cost, Development cost, Ramp-up cost, Production cost, and Pollution cost. Also, the model shows the effect of implementation of design for recyclable on revenue structure through revenue of used parts and revenue of recycled materials. A numerical example is used to evaluate the proposed model. Results show that fulfillment of Green Product Development not only can reduce the environmental impact of products but also it will increase profit of company in long term.
Keywords: Green Product, Design for Environment, C-V-P Model, Trade-off analysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20696719 Integration GIS–SCADA Power Systems to Enclosure Air Dispersion Model
Authors: Ibrahim Shaker, Amr El Hossany, Moustafa Osman, Mohamed El Raey
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This paper will explore integration model between GIS–SCADA system and enclosure quantification model to approach the impact of failure-safe event. There are real demands to identify spatial objects and improve control system performance. Nevertheless, the employed methodology is predicting electro-mechanic operations and corresponding time to environmental incident variations. Open processing, as object systems technology, is presented for integration enclosure database with minimal memory size and computation time via connectivity drivers such as ODBC:JDBC during main stages of GIS–SCADA connection. The function of Geographic Information System is manipulating power distribution in contrast to developing issues. In other ward, GIS-SCADA systems integration will require numerical objects of process to enable system model calibration and estimation demands, determine of past events for analysis and prediction of emergency situations for response training.Keywords: Air dispersion model, integration power system, SCADA systems, GIS system, environmental management.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15416718 MPSO based Model Order Formulation Scheme for Discrete PID Controller Design
Authors: S. N. Deepa, G. Sugumaran
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This paper proposes the novel model order formulation scheme to design a discrete PID controller for higher order linear time invariant discrete systems. Modified PSO (MPSO) based model order formulation technique has used to obtain the successful formulated second order system. PID controller is tuned to meet the desired performance specification by using pole-zero cancellation and proposed design procedures. Proposed PID controller is attached with both higher order system and formulated second order system. System specifications are tabulated and closed loop response is observed for stabilization process. The proposed method is illustrated through numerical examples from literature.Keywords: Discrete PID controller, Model Order Formulation, Modified Particle Swarm Optimization, Pole-Zero Cancellation
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16126717 A New Distribution and Application on the Lifetime Data
Authors: Gamze Ozel, Selen Cakmakyapan
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We introduce a new model called the Marshall-Olkin Rayleigh distribution which extends the Rayleigh distribution using Marshall-Olkin transformation and has increasing and decreasing shapes for the hazard rate function. Various structural properties of the new distribution are derived including explicit expressions for the moments, generating and quantile function, some entropy measures, and order statistics are presented. The model parameters are estimated by the method of maximum likelihood and the observed information matrix is determined. The potentiality of the new model is illustrated by means of a simulation study.
Keywords: Marshall-Olkin distribution, Rayleigh distribution, estimation, maximum likelihood.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13866716 Prediction of Bath Temperature Using Neural Networks
Authors: H. Meradi, S. Bouhouche, M. Lahreche
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In this work, we consider an application of neural networks in LD converter. Application of this approach assumes a reliable prediction of steel temperature and reduces a reblow ratio in steel work. It has been applied a conventional model to charge calculation, the obtained results by this technique are not always good, this is due to the process complexity. Difficulties are mainly generated by the noisy measurement and the process non linearities. Artificial Neural Networks (ANNs) have become a powerful tool for these complex applications. It is used a backpropagation algorithm to learn the neural nets. (ANNs) is used to predict the steel bath temperature in oxygen converter process for the end condition. This model has 11 inputs process variables and one output. The model was tested in steel work, the obtained results by neural approach are better than the conventional model.
Keywords: LD converter, bath temperature, neural networks.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18366715 Inversion Layer Effective Mobility Model for Pocket Implanted Nano Scale n-MOSFET
Authors: Muhibul Haque Bhuyan, Quazi D. M. Khosru
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Carriers scattering in the inversion channel of n- MOSFET dominates the drain current. This paper presents an effective electron mobility model for the pocket implanted nano scale n-MOSFET. The model is developed by using two linear pocket profiles at the source and drain edges. The channel is divided into three regions at source, drain and central part of the channel region. The total number of inversion layer charges is found for these three regions by numerical integration from source to drain ends and the number of depletion layer charges is found by using the effective doping concentration including pocket doping effects. These two charges are then used to find the effective normal electric field, which is used to find the effective mobility model incorporating the three scattering mechanisms, such as, Coulomb, phonon and surface roughness scatterings as well as the ballistic phenomena for the pocket implanted nano-scale n-MOSFET. The simulation results show that the derived mobility model produces the same results as found in the literatures.Keywords: Linear Pocket Profile, Pocket Implanted n-MOSFET, Effective Electric Field and Effective Mobility Model.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19076714 An Advanced Exponential Model for Seismic Isolators Having Hardening or Softening Behavior at Large Displacements
Authors: Nicolò Vaiana, Giorgio Serino
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In this paper, an advanced Nonlinear Exponential Model (NEM), able to simulate the uniaxial dynamic behavior of seismic isolators having a continuously decreasing tangent stiffness with increasing displacement in the relatively large displacements range and a hardening or softening behavior at large displacements, is presented. The mathematical model is validated by comparing the experimental force-displacement hysteresis loops obtained during cyclic tests, conducted on a helical wire rope isolator and a recycled rubber-fiber reinforced bearing, with those predicted analytically. Good agreement between the experimental and simulated results shows that the proposed model can be an effective numerical tool to predict the force-displacement relationship of seismic isolation devices within the large displacements range. Compared to the widely used Bouc-Wen model, unable to simulate the response of seismic isolators at large displacements, the proposed one allows to avoid the numerical solution of a first order nonlinear ordinary differential equation for each time step of a nonlinear time history analysis, thus reducing the computation effort. Furthermore, the proposed model can simulate the smooth transition of the hysteresis loops from small to large displacements by adopting only one set of five parameters determined from the experimental hysteresis loops having the largest amplitude.Keywords: Base isolation, hardening behavior, nonlinear exponential model, seismic isolators, softening behavior.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 8856713 Experimental Model for Instruction of Pre-Service Teachers in ICT Tools and E-learning Environments
Authors: Rachel Baruch
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This article describes the implementation of an experimental model for teaching ICT tools and digital environments in teachers training college. In most educational systems in the Western world, new programs were developed in order to bridge the digital gap between teachers and students. In spite of their achievements, these programs are limited due to several factors: The teachers in the schools implement new methods incorporating technological tools into the curriculum, but meanwhile the technology changes and advances. The interface of tools changes frequently, some tools disappear and new ones are invented. These conditions require an experimental model of training the pre-service teachers. The appropriate method for instruction within the domain of ICT tools should be based on exposing the learners to innovations, helping them to gain experience, teaching them how to deal with challenges and difficulties on their own, and training them. This study suggests some principles for this approach and describes step by step the implementation of this model.Keywords: ICT tools, e-learning, pre-service teachers.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10936712 Model Free Terminal Sliding Mode with Gravity Compensation: Application to an Exoskeleton-Upper Limb System
Authors: Sana Bembli, Nahla Khraief Haddad, Safya Belghith
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This paper deals with a robust model free terminal sliding mode with gravity compensation approach used to control an exoskeleton-upper limb system. The considered system is a 2-DoF robot in interaction with an upper limb used for rehabilitation. The aim of this paper is to control the flexion/extension movement of the shoulder and the elbow joints in presence of matched disturbances. In the first part, we present the exoskeleton-upper limb system modeling. Then, we controlled the considered system by the model free terminal sliding mode with gravity compensation. A stability study is realized. To prove the controller performance, a robustness analysis was needed. Simulation results are provided to confirm the robustness of the gravity compensation combined with to the Model free terminal sliding mode in presence of uncertainties.Keywords: Exoskeleton-upper limb system, gravity compensation, model free terminal sliding mode, robustness analysis, Monte Carlo, H∞ methods.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7366711 Building a Trend Based Segmentation Method with SVR Model for Stock Turning Detection
Authors: Jheng-Long Wu, Pei-Chann Chang, Yi-Fang Pan
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This research focus on developing a new segmentation method for improving forecasting model which is call trend based segmentation method (TBSM). Generally, the piece-wise linear representation (PLR) can finds some of pair of trading points is well for time series data, but in the complicated stock environment it is not well for stock forecasting because of the stock has more trends of trading. If we consider the trends of trading in stock price for the trading signal which it will improve the precision of forecasting model. Therefore, a TBSM with SVR model used to detect the trading points for various stocks of Taiwanese and America under different trend tendencies. The experimental results show our trading system is more profitable and can be implemented in real time of stock market
Keywords: Trend based segmentation method, support vector machine, turning detection, stock forecasting.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 31666710 State Feedback Speed Controller for Turbocharged Diesel Engine and Its Robustness
Authors: Dileep Malkhede, Bhartendu Seth
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In this paper, the full state feedback controllers capable of regulating and tracking the speed trajectory are presented. A fourth order nonlinear mean value model of a 448 kW turbocharged diesel engine published earlier is used for the purpose. For designing controllers, the nonlinear model is linearized and represented in state-space form. Full state feedback controllers capable of meeting varying speed demands of drivers are presented. Main focus here is to investigate sensitivity of the controller to the perturbations in the parameters of the original nonlinear model. Suggested controller is shown to be highly insensitive to the parameter variations. This indicates that the controller is likely perform with same accuracy even after significant wear and tear of engine due to its use for years.Keywords: Diesel engine model, Engine speed control, State feedback controller, Controller robustness.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22216709 Parametric Optimization of Hospital Design
Authors: M. K. Holst, P. H. Kirkegaard, L. D. Christoffersen
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Present paper presents a parametric performancebased design model for optimizing hospital design. The design model operates with geometric input parameters defining the functional requirements of the hospital and input parameters in terms of performance objectives defining the design requirements and preferences of the hospital with respect to performances. The design model takes point of departure in the hospital functionalities as a set of defined parameters and rules describing the design requirements and preferences.Keywords: Architectural Layout Design, Hospital Design, Parametric design, Performance-based models.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 27176708 Modified Hankel Matrix Approach for Model Order Reduction in Time Domain
Authors: C. B. Vishwakarma
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The author presented a method for model order reduction of large-scale time-invariant systems in time domain. In this approach, two modified Hankel matrices are suggested for getting reduced order models. The proposed method is simple, efficient and retains stability feature of the original high order system. The viability of the method is illustrated through the examples taken from literature.
Keywords: Model Order Reduction, Stability, Hankel Matrix, Time-Domain, Integral Square Error.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20776707 Effect of Chloroform on Aerobic Biodegradation of Organic Solvents in Pharmaceutical Wastewater
Authors: Balasubramanian P, Ligy Philip, S. Murty Bhallamudi
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In this study, cometabolic biodegradation of chloroform was experimented with mixed cultures in the presence of various organic solvents like methanol, ethanol, isopropanol, acetone, acetonitrile and toluene as these are predominant discharges in pharmaceutical industries. Toluene and acetone showed higher specific chloroform degradation rate when compared to other compounds. Cometabolic degradation of chloroform was further confirmed by observation of free chloride ions in the medium. An extended Haldane model, incorporating the inhibition due to chloroform and the competitive inhibition between primary substrates, was developed to predict the biodegradation of primary substrates, cometabolic degradation of chloroform and the biomass growth. The proposed model is based on the use of biokinetic parameters obtained from single substrate degradation studies. The model was able to satisfactorily predict the experimental results of ternary and quaternary mixtures. The proposed model can be used for predicting the performance of bioreactors treating discharges from pharmaceutical industries.Keywords: Chloroform, Cometabolic biodegradation, Competitive inhibition, Extended Haldane model, Pharmaceuticalindustry.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 27896706 A Hybrid DEA Model for the Measurement of the Enviromental Performance
Authors: A. Hadi-Vencheh, N. Shayesteh Moghadam
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Data envelopment analysis (DEA) has gained great popularity in environmental performance measurement because it can provide a synthetic standardized environmental performance index when pollutants are suitably incorporated into the traditional DEA framework. Since some of the environmental performance indicators cannot be controlled by companies managers, it is necessary to develop the model in a way that it could be applied when discretionary and/or non-discretionary factors were involved. In this paper, we present a semi-radial DEA approach to measuring environmental performance, which consists of non-discretionary factors. The model, then, has been applied on a real case.
Keywords: Environmental performance, efficiency, non-discretionary variables, data envelopment analysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13766705 Review of Trust Models in Wireless Sensor Networks
Authors: V. Uma Rani, K. Soma Sundaram
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The major challenge faced by wireless sensor networks is security. Because of dynamic and collaborative nature of sensor networks the connected sensor devices makes the network unusable. To solve this issue, a trust model is required to find malicious, selfish and compromised insiders by evaluating trust worthiness sensors from the network. It supports the decision making processes in wireless sensor networks such as pre key-distribution, cluster head selection, data aggregation, routing and self reconfiguration of sensor nodes. This paper discussed the kinds of trust model, trust metrics used to address attacks by monitoring certain behavior of network. It describes the major design issues and their countermeasures of building trust model. It also discusses existing trust models used in various decision making process of wireless sensor networks.
Keywords: Attacks, Security, Trust, Trust model, Wireless sensor network.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 45656704 Basic Tendency Model in Complete Factor Synergetics of Complex Systems
Authors: Li Zong-Cheng
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The deviation between the target state variable and the practical state variable should be used to form the state tending factor of complex systems, which can reflect the process for the complex system to tend rationalization. Relating to the system of basic equations of complete factor synergetics consisting of twenty nonlinear stochastic differential equations, the two new models are considered to set, which should be called respectively the rationalizing tendency model and the non- rationalizing tendency model. Therefore we can extend the theory of programming with the objective function & constraint condition suitable only for the realm of man-s activities into the new analysis with the tendency function & constraint condition suitable for all the field of complex system.Keywords: complex system, complete factor synergetics, basicequation, rationalizing tendency model, non-rationalizing tendencymodel.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13356703 Simulation of Snow Covers Area by a Physical based Model
Authors: Hossein Zeinivand, Florimond De Smedt
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Snow cover is an important phenomenon in hydrology, hence modeling the snow accumulation and melting is an important issue in places where snowmelt significantly contributes to runoff and has significant effect on water balance. The physics-based models are invariably distributed, with the basin disaggregated into zones or grid cells. Satellites images provide valuable data to verify the accuracy of spatially distributed model outputs. In this study a spatially distributed physically based model (WetSpa) was applied to predict snow cover and melting in the Latyan dam watershed in Iran. Snowmelt is simulated based on an energy balance approach. The model is applied and calibrated with one year of observed daily precipitation, air temperature, windspeed, and daily potential evaporation. The predicted snow-covered area is compared with remotely sensed images (MODIS). The results show that simulated snow cover area SCA has a good agreement with satellite image snow cover area SCA from MODIS images. The model performance is also tested by statistical and graphical comparison of simulated and measured discharges entering the Latyan dam reservoir.Keywords: Physical based model, Satellite image, Snow covers.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18646702 Dynamic Economic Dispatch Constrained by Wind Power Weibull Distribution: A Here-and-Now Strategy
Authors: Mostafa A. Elshahed, Magdy M. Elmarsfawy, Hussain M. Zain Eldain
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In this paper, a Dynamic Economic Dispatch (DED) model is developed for the system consisting of both thermal generators and wind turbines. The inclusion of a significant amount of wind energy into power systems has resulted in additional constraints on DED to accommodate the intermittent nature of the output. The probability of stochastic wind power based on the Weibull probability density function is included in the model as a constraint; A Here-and-Now Approach. The Environmental Protection Agency-s hourly emission target, which gives the maximum emission during the day, is used as a constraint to reduce the atmospheric pollution. A 69-bus test system with non-smooth cost function is used to illustrate the effectiveness of the proposed model compared with static economic dispatch model with including the wind power.
Keywords: Dynamic Economic Dispatch, StochasticOptimization, Weibull Distribution, Wind Power
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 29596701 Seismic Assessment of Old Existing RC Buildings with Masonry Infill in Madinah as per ASCE
Authors: Tarek M. Alguhane, Ayman H. Khalil, M. N. Fayed, Ayman M. Ismail
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An existing RC building in Madinah is seismically evaluated with and without infill wall. Four model systems have been considered i.e. model I (no infill), model IIA (strut infill-update from field test), model IIB (strut infill- ASCE/SEI 41) and model IIC (strut infill-Soft storey- ASCE/SEI 41). Three dimensional pushover analyses have been carried out using SAP2000 software incorporating inelastic material behavior for concrete, steel and infill walls. Infill wall has been modeled as equivalent strut according to suggested equation matching field test measurements and to the ASCE/SEI 41 equation. The effect of building modeling on the performance point as well as capacity and demand spectra due to EQ design spectrum function in Madinah area has been investigated. The response modification factor (R) for the 5 story RC building is evaluated from capacity and demand spectra (ATC-40) for the studied models. The results are summarized and discussed.
Keywords: Infill wall, Pushover Analysis, Response Modification Factor, Seismic Assessment.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 32586700 Application of a Generalized Additive Model to Reveal the Relations between the Density of Zooplankton with Other Variables in the West Daya Bay, China
Authors: Weiwen Li, Hao Huang, Chengmao You, Jianji Liao, Lei Wang, Lina An
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Zooplankton are a central issue in the ecology which makes a great contribution to maintaining the balance of an ecosystem. It is critical in promoting the material cycle and energy flow within the ecosystems. A generalized additive model (GAM) was applied to analyze the relationships between the density (individuals per m³) of zooplankton and other variables in West Daya Bay. All data used in this analysis (the survey month, survey station (longitude and latitude), the depth of the water column, the superficial concentration of chlorophyll a, the benthonic concentration of chlorophyll a, the number of zooplankton species and the number of zooplankton species) were collected through monthly scientific surveys during January to December 2016. GLM model (generalized linear model) was used to choose the significant variables’ impact on the density of zooplankton, and the GAM was employed to analyze the relationship between the density of zooplankton and the significant variables. The results showed that the density of zooplankton increased with an increase of the benthonic concentration of chlorophyll a, but decreased with a decrease in the depth of the water column. Both high numbers of zooplankton species and the overall total number of zooplankton individuals led to a higher density of zooplankton.
Keywords: Density, generalized linear model, generalized additive model, the West Daya Bay, zooplankton.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10366699 Numerical Simulation and Experimental Validation of the Tire-Road Separation in Quarter-Car Model
Authors: Quy Dang Nguyen, Reza Nakhaie Jazar
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The paper investigates vibration dynamics of tire-road separation for a quarter-car model; this separation model is developed to be close to the real situation considering the tire is able to separate from the ground plane. A set of piecewise linear mathematical models is developed and matches the in-contact and no-contact states to be considered as mother models for further investigations. The bound dynamics are numerically simulated in the time response and phase portraits. The separation analysis may determine which values of suspension parameters can delay and avoid the no-contact phenomenon, which results in improving ride comfort and eliminating the potentially dangerous oscillation. Finally, model verification is carried out in the MSC-ADAMS environment.
Keywords: Quarter-car vibrations, tire-road separation, separation analysis, separation dynamics, ride comfort, ADAMS validation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2026698 Automata-Based String Analysis for Detecting Malware in Android Programs
Authors: Assad Maalouf, Lunjin Lu, James Lynott
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We design and implement a precise model of string operations using finite state machine transformers and state transformers to approximate the values string variables can take throughout the execution of the program.We use our model to analyze Android program string variables. Our experimental results show that our string analysis is very efficient at detecting the contextual effect of string operations on the string variables. Our model proved to be very useful when it came to verifying statements about the string variables of the program.Keywords: Abstract interpretation, android, static analysis, string analysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7246697 A New Model of English-Vietnamese Bilingual Information Retrieval System
Authors: Chinh Trong Nguyen, Dang Tuan Nguyen
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In this paper, we propose a new model of English- Vietnamese bilingual Information Retrieval system. Although there are so many CLIR systems had been researched and built, the accuracy of searching results in different languages that the CLIR system supports still need to improve, especially in finding bilingual documents. The problems identified in this paper are the limitation of machine translation-s result and the extra large collections of document to be found. So we try to establish a different model to overcome these problems.Keywords: Bilingual Information Retrieval, Cross-lingual Information Retrieval, Bilingual Web sites.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16276696 Random Oracle Model of Information Hiding System
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Random Oracle Model (ROM) is an effective method for measuring the practical security of cryptograph. In this paper, we try to use it into information hiding system (IHS). Because IHS has its own properties, the ROM must be modified if it is used into IHS. Firstly, we fully discuss why and how to modify each part of ROM respectively. The main changes include: 1) Divide the attacks that IHS may be suffered into two phases and divide the attacks of each phase into several kinds. 2) Distinguish Oracles and Black-boxes clearly. 3) Define Oracle and four Black-boxes that IHS used. 4) Propose the formalized adversary model. And 5) Give the definition of judge. Secondly, based on ROM of IHS, the security against known original cover attack (KOCA-KOCA-security) is defined. Then, we give an actual information hiding scheme and prove that it is KOCA-KOCA-secure. Finally, we conclude the paper and propose the open problems of further research.Keywords: Attack, Information Hiding, Provable Security, Random Oracle Model.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13476695 Hemodynamic Characteristics in the Human Carotid Artery Model Induced by Blood-Arterial Wall Interactions
Authors: Taewon Seo
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The characteristics of physiological blood flow in human carotid arterial bifurcation model have been numerically studied using a fully coupled fluid-structure interaction (FSI) analysis. This computational model with the fluid-structure interaction is constructed to investigate the flow characteristics and wall shear stress in the carotid artery. As the flow begins to decelerate after the peak flow, a large recirculation zone develops at the non-divider wall of both internal carotid artery (ICA) and external carotid artery (ECA) in FSI model due to the elastic energy stored in the expanding compliant wall. The calculated difference in wall shear stress (WSS) in both Non-FSI and FSI models is a range of between 5 and 11% at the mean WSS. The low WSS corresponds to regions of carotid artery that are more susceptible to atherosclerosis.
Keywords: Carotid artery, Fluid-structure interaction, Hemodynamics, Wall shear stress.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28666694 Reconstruction of a Genome-Scale Metabolic Model to Simulate Uncoupled Growth of Zymomonas mobilis
Authors: Maryam Saeidi, Ehsan Motamedian, Seyed Abbas Shojaosadati
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Zymomonas mobilis is known as an example of the uncoupled growth phenomenon. This microorganism also has a unique metabolism that degrades glucose by the Entner–Doudoroff (ED) pathway. In this paper, a genome-scale metabolic model including 434 genes, 757 reactions and 691 metabolites was reconstructed to simulate uncoupled growth and study its effect on flux distribution in the central metabolism. The model properly predicted that ATPase was activated in experimental growth yields of Z. mobilis. Flux distribution obtained from model indicates that the major carbon flux passed through ED pathway that resulted in the production of ethanol. Small amounts of carbon source were entered into pentose phosphate pathway and TCA cycle to produce biomass precursors. Predicted flux distribution was in good agreement with experimental data. The model results also indicated that Z. mobilis metabolism is able to produce biomass with maximum growth yield of 123.7 g (mol glucose)-1 if ATP synthase is coupled with growth and produces 82 mmol ATP gDCW-1h-1. Coupling the growth and energy reduced ethanol secretion and changed the flux distribution to produce biomass precursors.Keywords: Genome-scale metabolic model, Zymomonas mobilis, uncoupled growth, flux distribution, ATP dissipation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11396693 Towards a Simulation Model to Ensure the Availability of Machines in Maintenance Activities
Authors: Maryam Gallab, Hafida Bouloiz, Youness Chater, Mohamed Tkiouat
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The aim of this paper is to present a model based on multi-agent systems in order to manage the maintenance activities and to ensure the reliability and availability of machines just with the required resources (operators, tools). The interest of the simulation is to solve the complexity of the system and to find results without cost or wasting time. An implementation of the model is carried out on the AnyLogic platform to display the defined performance indicators.Keywords: Maintenance, complexity, simulation, multi-agent systems, AnyLogic platform.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15066692 A Study on a Discrete Event Simulation Model for Availability Analysis of Weapon Systems
Authors: Hye Lyeong Kim, Sang Yeong Choi
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This paper discusses a discrete event simulation model for the availability analysis of weapon systems. This model incorporates missions, operational tasks and system reliability structures to analyze the availability of a weapon system. The proposed simulation model consists of 5 modules: Simulation Engine, Maintenance Organizations, System, its Mission Profile and RBD which are based on missions and operational tasks. Simulation Engine executes three kinds of discrete events in chronological order. The events are mission events generated by Mission Profile, failure events generated by System, and maintenance events executed by Maintenance Organization. Finally, this paper shows the case study of a system's availability analysis and mission reliability using the simulation model.Keywords: MTBF (Mean Time Between Failure), MTTR (Mean Time To Repair), Availability, Reliability, RBD (Reliability Block Diagram)
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26486691 Numerical Analysis of Concrete Crash Barriers
Authors: J. Kala, P. Hradil, V. Salajka
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Reinforced concrete crash barriers used in road traffic must meet a number of criteria. Crash barriers are laid lengthwise, one behind another, and joined using specially designed steel locks. While developing BSV reinforced concrete crash barriers (type ŽPSV), experiments and calculations aimed to optimize the shape of a newly designed lock and the reinforcement quantity and distribution in a crash barrier were carried out. The tension carrying capacity of two parallelly joined locks was solved experimentally. Based on the performed experiments, adjustments of nonlinear properties of steel were performed in the calculations. The obtained results served as a basis to optimize the lock design using a computational model that takes into account the plastic behaviour of steel and the influence of the surrounding concrete [6]. The response to the vehicle impact has been analyzed using a specially elaborated complex computational model, comprising both the nonlinear model of the damping wall or crash barrier and the detailed model of the vehicle [7].Keywords: Crash Barrier, impact, static analysis, concrete nonlinear model.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3242