Search results for: Round Time.
6536 Hydrodynamic Processes in Bubbly Liquid Flow in Tubes and Nozzles
Authors: Raisa Kh. Bolotnova, Marat N. Galimzianov, Andrey S. Topolnikov, Valeria A. Buzina, Uliana O. Agisheva
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The hydrodynamic processes in bubbly liquid flowing in tubes and nozzles are studied theoretically and numerically. The principal regularities of non-stationary processes of boiling liquid outflow are established under conditions of experiments when the depressurization of a tube with high pressure inside occurs. The steady-state solution of bubbly liquid flow in the nozzle of round cross section with high pressure and temperature conditions inside bubbles is studied accounting for phase transition and chemical reactions.Keywords: bubbly liquid, cavitation, chemical reactions, phase transition.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20306535 Analysis of Control by Flattening of the Welded Tubes
Authors: Hannachi Med Tahar, H. Djebaili, B. Daheche
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In this approach, we have tried to describe the flattening of welded tubes, and its experimental application. The test is carried out at the (National product processing company dishes and tubes production). Usually, the final products (tubes) undergo a series of non-destructive inspection online and offline welding, and obviously destructive mechanical testing (bending, flattening, flaring, etc.). For this and for the purpose of implementing the flattening test, which applies to the processing of round tubes in other forms, it took four sections of welded tubes draft (before stretching hot) and welded tubes finished (after drawing hot and annealing), it was also noted the report 'health' flattened tubes must not show or crack or tear. The test is considered poor if it reveals a lack of ductility of the metal.
Keywords: Flattening, destructive testing, tube drafts, finished tube, Castem 2001.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12626534 Calculation of the Thermal Stresses in an Elastoplastic Plate Heated by Local Heat Source
Authors: M. Khaing, A. V. Tkacheva
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The work is devoted to solving the problem of temperature stresses, caused by the heating point of the round plate. The plate is made of elastoplastic material, so the Prandtl-Reis model is used. A piecewise-linear condition of the Ishlinsky-Ivlev flow is taken as the loading surface, in which the yield stress depends on the temperature. Piecewise-linear conditions (Treska or Ishlinsky-Ivlev), in contrast to the Mises condition, make it possible to obtain solutions of the equilibrium equation in an analytical form. In the problem under consideration, using the conditions of Tresca, it is impossible to obtain a solution. This is due to the fact that the equation of equilibrium ceases to be satisfied when the two Tresca conditions are fulfilled at once. Using the conditions of plastic flow Ishlinsky-Ivlev allows one to solve the problem. At the same time, there are also no solutions on the edge of the Ishlinsky-Ivlev hexagon in the plane-stressed state. Therefore, the authors of the article propose to jump from the edge to the edge of the mine edge, which gives an opportunity to obtain an analytical solution. At the same time, there is also no solution on the edge of the Ishlinsky-Ivlev hexagon in a plane stressed state; therefore, in this paper, the authors of the article propose to jump from the side to the side of the mine edge, which gives an opportunity to receive an analytical solution. The paper compares solutions of the problem of plate thermal deformation. One of the solutions was obtained under the condition that the elastic moduli (Young's modulus, Poisson's ratio) which depend on temperature. The yield point is assumed to be parabolically temperature dependent. The main results of the comparisons are that the region of irreversible deformation is larger in the calculations obtained for solving the problem with constant elastic moduli. There is no repeated plastic flow in the solution of the problem with elastic moduli depending on temperature. The absolute value of the irreversible deformations is higher for the solution of the problem in which the elastic moduli are constant; there are also insignificant differences in the distribution of the residual stresses.Keywords: Temperature stresses, elasticity, plasticity, Ishlinsky-Ivlev condition, plate, annular heating, elastic moduli.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7216533 Surgery Scheduling Using Simulation with Arena
Authors: J. A. López, C.I. López, J.E. Olguín, C. Camargo, J. M. López
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The institutions seek to improve their performance and quality of service, so that their patients are satisfied. This research project aims, conduct a time study program in the area of gynecological surgery, to determine the current level of capacity and optimize the programming time in order to adequately respond to demand. The system is analyzed by waiting lines and uses the simulation using ARENA to evaluate proposals for improvement and optimization programming time each of the surgeries.
Keywords: Time study, waiting lines, reducing time, simulation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 27396532 Does Leisure Time Use Contribute to a Wage Increase of the Thai People?
Authors: Siriwan Saksiriruthai
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This paper develops models to analyze the relationship between leisure time and wage change. Using Thailand-s Time Use Survey and Labor Force Survey data, the estimation of wage changes in response to leisure time change indicates that media receiving, personal care and social participation and volunteer activities are the ones that significantly raise hourly wages. Thus, the finding suggests the stimulation in time use for media access to enhance knowledge and productivity, personal care for attractiveness and healthiness in order to raise productivity, and social activities to develop connections for possible future opportunities including wage increase. These activities should be promoted for productive leisure time and for welfare improvement.Keywords: Leisure, wage, time use, Thailand.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15776531 A Study on Characteristics and Geometric Parameters of the Flat Porous Aerostatic Bearing
Authors: T. Y. Huang, B. Z. Wang, S. C. Lin, S. Y. Hsu
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A CFD software was employed to analyze the characteristics of the flat round porous aerostatic bearings. The effects of gap between the bearing and the guide way and the porosity of the porous material on the load capacity of the bearing were studied. The adequacy of the simulation model and the approach was verified. From the parametric study, it is found that the depth of the flow path does not influence the load capacity of the bearing; the load capacity of the bearing will decrease if the thickness of the porous material increases or the porous material protrudes above the bearing housing; the variation of the chamfer at the edge of the bearing does not affect the bearing load capacity. For a bearing with an air gap of 5μm and a porosity of 0.1, the average load capacity and the pressure distribution of the bearing are nearly unchanged no matter the bearing moves at a constant or a varying speed.
Keywords: Aerostatic bearing, Load capacity, Porosity, Porous material.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 25816530 Finite Time Symplectic Synchronization between Two Different Chaotic Systems
Authors: Chunming Xu
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In this paper, the finite-time symplectic synchronization between two different chaotic systems is investigated. Based on the finite-time stability theory, a simple adaptive feedback scheme is proposed to realize finite-time symplectic synchronization for the Lorenz and L¨u systems. Numerical examples are provided to show the effectiveness of the proposed method.Keywords: Chaotic systems, symplectic synchronization, finite-time synchronization, adaptive controller.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9496529 Discovery of Time Series Event Patterns based on Time Constraints from Textual Data
Authors: Shigeaki Sakurai, Ken Ueno, Ryohei Orihara
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This paper proposes a method that discovers time series event patterns from textual data with time information. The patterns are composed of sequences of events and each event is extracted from the textual data, where an event is characteristic content included in the textual data such as a company name, an action, and an impression of a customer. The method introduces 7 types of time constraints based on the analysis of the textual data. The method also evaluates these constraints when the frequency of a time series event pattern is calculated. We can flexibly define the time constraints for interesting combinations of events and can discover valid time series event patterns which satisfy these conditions. The paper applies the method to daily business reports collected by a sales force automation system and verifies its effectiveness through numerical experiments.
Keywords: Text mining, sequential mining, time constraints, daily business reports.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14786528 Effects of Sowing Time on Yield and Oil Content of Different Sunflower Genotypes in Years with Different Water Supply
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We examined the effects of the sowing time on the yield production and oil content of the sunflower hybrids in 2010 and 2012. The crop year and the sowing time had both a strong impact on the yield, on the oil- content and yield. By delaying the sowing time both the yield crop result and the oil yield increased. In 2010 in terms of crop yield and oil yield results PR64H42 was the best, in 2012 NK Neoma, in all three sowing times. The oil content of the hybrids was better in 2010. The highest oil content was recorded at early sowing time. We found out that the hybrid had a stronger impact in 2010 on both crop yield result and on oil content than in 2012. The sowing time played a bigger role regarding yield results in 2012. In addition the sowing time influenced oil content development highly.
Keywords: Genotypes, oil content, sowing time, sunflower, yield.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19726527 Development of Autonomous Line-Following Soccer Robots
Authors: A. A. Shafie, M. F. Alias, M. H. Ali
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The main objective of this project is to build an autonomous microcontroller-based mobile robot for a local robot soccer competition. The black competition field is equipped with white lines to serve as the guidance path for competing robots. Two prototypes of soccer robot embedded with the Basic Stamp II microcontroller have been developed. Two servo motors are used as the drive train for the first prototype whereas the second prototype uses two DC motors as its drive train. To sense the lines, lightdependent resistors (LDRs) supply the analog inputs for the microcontroller. The performances of both prototypes are evaluated. The DC motor-driven robot has produced better trajectory control over the one using servo motors and has brought the team into the final round.Keywords: Soccer robot, Obstacle detection, Differential drive, Line following.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16396526 Study and Enhancement of Flash Evaporation Desalination Utilizing the Ocean Thermocline and Discharged heat
Authors: Sami Mutair, Yasuyuki Ikegami
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This paper reports on the results of experimental investigations of flash evaporation from superheated jet issues vertically upward from a round straight nozzle of 81.3 mm diameter. For the investigated range of jet superheat degree and velocity, it was shown that flash evaporation enhances with initial temperature increase. Due to the increase of jet inertia and subsequently the delay of jet shattering, increase of jet velocity was found to result in increase of evaporation "delay period". An empirical equation predicts the jet evaporation completion height was developed, this equation is thought to be useful in designing the flash evaporation chamber. In attempts for enhancement of flash evaporation, use of steel wire mesh located at short distance downstream was found effective with no consequent pressure drop.Keywords: Enhancement; Flash Evaporation; OTEC; superheated jet
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 30256525 Principal Component Analysis using Singular Value Decomposition of Microarray Data
Authors: Dong Hoon Lim
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A series of microarray experiments produces observations of differential expression for thousands of genes across multiple conditions. Principal component analysis(PCA) has been widely used in multivariate data analysis to reduce the dimensionality of the data in order to simplify subsequent analysis and allow for summarization of the data in a parsimonious manner. PCA, which can be implemented via a singular value decomposition(SVD), is useful for analysis of microarray data. For application of PCA using SVD we use the DNA microarray data for the small round blue cell tumors(SRBCT) of childhood by Khan et al.(2001). To decide the number of components which account for sufficient amount of information we draw scree plot. Biplot, a graphic display associated with PCA, reveals important features that exhibit relationship between variables and also the relationship of variables with observations.
Keywords: Principal component analysis, singular value decomposition, microarray data, SRBCT
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 32396524 Universal Qibla and Prayer Time Finder
Authors: M. Z. Ibrahim, M. Z. Norashikin
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People nowadays love to travel around the world. Regardless of their location and time, they especially Muslims still need to perform their five times prayer. Normally for travelers, they need to bring maps, compass and for Muslim, they even have to bring Qibla pointer when they travel. It is slightly difficult to determine the Qibla direction and to know the time for each prayer. In this paper we present a new electronic device called Universal Qibla and Prayer Time Finder to locate the Qibla direction and to determine each prayer time based on the current user-s location. This device use PIC microcontroller equipped with digital compass and Global Positioning System (GPS) where it will display the exact Qibla direction and prayer time automatically at any place in the world. This device is reliable, user friendly and accurate in determining the Qibla direction and prayer time.Keywords: Digital compass, embedded system, global position system, prayer time, qibla
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 39536523 Sub-Impact Phenomenon of Elasto-Plastic Free-Free Beam during a Strike
Authors: H. Rong, X. C. Yin, J. Yang, Y. N. Shen
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Based on Rayleigh beam theory, the sub-impacts of a free-free beam struck horizontally by a round-nosed rigid mass is simulated by the finite difference method and the impact-separation conditions. In order to obtain the sub-impact force, a uniaxial compression elastic-plastic contact model is employed to analyze the local deformation field on contact zone. It is found that the horizontal impact is a complicated process including the elastic plastic sub-impacts in sequence. There are two sub-zones of sub-impact. In addition, it found that the elastic energy of the free-free beam is more suitable for the Poisson collision hypothesis to explain compression and recovery processes.Keywords: beam, sub-impact, elastic-plastic deformation, finite difference method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18386522 FPGA Hardware Implementation and Evaluation of a Micro-Network Architecture for Multi-Core Systems
Authors: Yahia Salah, Med Lassaad Kaddachi, Rached Tourki
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This paper presents the design, implementation and evaluation of a micro-network, or Network-on-Chip (NoC), based on a generic pipeline router architecture. The router is designed to efficiently support traffic generated by multimedia applications on embedded multi-core systems. It employs a simplest routing mechanism and implements the round-robin scheduling strategy to resolve output port contentions and minimize latency. A virtual channel flow control is applied to avoid the head-of-line blocking problem and enhance performance in the NoC. The hardware design of the router architecture has been implemented at the register transfer level; its functionality is evaluated in the case of the two dimensional Mesh/Torus topology, and performance results are derived from ModelSim simulator and Xilinx ISE 9.2i synthesis tool. An example of a multi-core image processing system utilizing the NoC structure has been implemented and validated to demonstrate the capability of the proposed micro-network architecture. To reduce complexity of the image compression and decompression architecture, the system use image processing algorithm based on classical discrete cosine transform with an efficient zonal processing approach. The experimental results have confirmed that both the proposed image compression scheme and NoC architecture can achieve a reasonable image quality with lower processing time.
Keywords: Generic Pipeline Network-on-Chip Router Architecture, JPEG Image Compression, FPGA Hardware Implementation, Performance Evaluation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 30896521 Energy Efficient Data Aggregation in Sensor Networks with Optimized Cluster Head Selection
Authors: D. Naga Ravi Kiran, C. G. Dethe
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Wireless Sensor Network (WSN) routing is complex due to its dynamic nature, computational overhead, limited battery life, non-conventional addressing scheme, self-organization, and sensor nodes limited transmission range. An energy efficient routing protocol is a major concern in WSN. LEACH is a hierarchical WSN routing protocol to increase network life. It performs self-organizing and re-clustering functions for each round. This study proposes a better sensor networks cluster head selection for efficient data aggregation. The algorithm is based on Tabu search.Keywords: Wireless Sensor Network (WSN), LEACH, Clustering, Tabu Search.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20206520 Sensitivity Analysis of Real-Time Systems
Authors: Benjamin Gorry, Andrew Ireland, Peter King
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Verification of real-time software systems can be expensive in terms of time and resources. Testing is the main method of proving correctness but has been shown to be a long and time consuming process. Everyday engineers are usually unwilling to adopt formal approaches to correctness because of the overhead associated with developing their knowledge of such techniques. Performance modelling techniques allow systems to be evaluated with respect to timing constraints. This paper describes PARTES, a framework which guides the extraction of performance models from programs written in an annotated subset of C.Keywords: Performance Modelling, Real-time, SensitivityAnalysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15006519 Circadian Clock and Subjective Time Perception: A Simple Open Source Application for the Analysis of Induced Time Perception in Humans
Authors: Agata M. Kołodziejczyk, Mateusz Harasymczuk, Pierre-Yves Girardin, Lucie Davidová
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Subjective time perception implies connection to cognitive functions, attention, memory and awareness, but a little is known about connections with homeostatic states of the body coordinated by circadian clock. In this paper, we present results from experimental study of subjective time perception in volunteers performing physical activity on treadmill in various phases of their circadian rhythms. Subjects were exposed to several time illusions simulated by programmed timing systems. This study brings better understanding for further improvement of of work quality in isolated areas.
Keywords: Biological clock, light, time illusions, treadmill.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15136518 A Simple Qos Scheduler for Mobile Wimax
Authors: Komala Kalyanam, Pushpam Indumathi
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WiMAX is defined as Worldwide Interoperability for Microwave Access by the WiMAX Forum, formed in June 2001 to promote conformance and interoperability of the IEEE 802.16 standard, officially known as WirelessMAN. The attractive features of WiMAX technology are very high throughput and Broadband Wireless Access over a long distance. A detailed simulation environment is demonstrated with the UGS, nrtPS and ertPS service classes for throughput, delay and packet delivery ratio for a mixed environment of fixed and mobile WiMAX. A simple mobility aspect is considered for the mobile WiMAX and the PMP mode of transmission is considered in TDD mode. The Network Simulator 2 (NS-2) is the tool which is used to simulate the WiMAX network scenario. A simple Priority Scheduler and Weighted Round Robin Schedulers are the WiMAX schedulers used in the research workKeywords: ertPS, Mobile WiMAX, scheduler.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18946517 A Dual Model for Efficiency Evaluation Considering Time Lag Effect
Authors: Yan Shuang Zhang, Taehan Lee, Byung Ho Jeong
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A DEA model can generally evaluate the performance using multiple inputs and outputs for the same period. However, it is hard to avoid the production lead time phenomenon some times, such as long-term project or marketing activity. A couple of models have been suggested to capture this time lag issue in the context of DEA. This paper develops a dual-MPO model to deal with time lag effect in evaluating efficiency. A numerical example is also given to show that the proposed model can be used to get efficiency and reference set of inefficient DMUs and to obtain projected target value of input attributes for inefficient DMUs to be efficient.
Keywords: DEA, efficiency, time lag, dual problem.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17986516 Hybrid System Configurations and Charging Strategies for Isolated Electric Tuk-Tuk Charging Station in South Africa
Authors: L. Bokopane, K. Kusakana, H. J. Vermaark
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The success of renewable powered electric vehicle charging station in isolated areas depends highly on the availability and sustainability of renewable resources all year round at a selected location. The main focus of this paper is to discuss the possible charging strategies that could be implemented to find the best possible configuration of an electric Tuk-Tuk charging station at a given location within South Africa. The charging station is designed, modeled and simulated to evaluate its performances. The technoeconomic analysis of different feasible supply configurations of the charging station using renewable energies is simulated using HOMER software and the results compared in order to select the best possible charging strategies in terms of cost of energy consumed.
Keywords: Electric Tuk-Tuk, Renewable energy, Energy Storage, Hybrid systems, HOMER.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 25016515 Predicting Residence Time of Pollutants in Transient Storage Zones of Rivers by Genetic Programming
Authors: Rajeev R. Sahay
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Rivers have transient storage or dead zones where injected pollutants or solutes are entrapped for considerable period of time, known as residence time, before being released into the main flowing zones of rivers. In this study, a new empirical expression for residence time, implementing genetic programming on published dispersion data, has been derived. The proposed expression uses few hydraulic and geometric characteristics of rivers which are normally known to the authorities. When compared with some reported expressions, based on various statistical indices, it can be concluded that the proposed expression predicts the residence time of pollutants in natural rivers more accurately.Keywords: Parameter estimation, pollutant transport, residence time, rivers, transient storage.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12526514 Effect of Magnetic Field on Seed Germination of Two Wheat Cultivars
Authors: Ahmad Gholami , Saeed Sharafi, Hamid Abbasdokht
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The effect of magnetic field on germination characteristics of two wheat Seeds has been studied under laboratory conditions. Seeds were magnetically exposed to magnetic field strengths, 125 or 250mT for different periods of time. Mean germination time and the time required to obtain 10, 25, 50, 75 and 90%of seeds to germinate were calculated. The germination time for each treatment were in general, higher than corresponding control values, in the other word in treated seeds time required for mean seed germination time increased nearly 3 hours in compared non treated control seeds. T10 for doses D5, D6, D11 and D12 significantly higher than the control values for both cultivars. Mean germination time (MGT) in both cultivars significantly increased when the time of seed exposed at magnetic field treatments increased , about 3 and 2 hour respectively for Omid and BCR cultivars.Keywords: wheat, cultivar, germination test, magnetic field
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 40406513 Gravitational and Centrifugal Forces in the Nut-Kerr-Newman Space-Time
Authors: Atikur Rahman Baizid, Md. Elias Uddin Biswas, Ahsan Habib
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Nayak et al have discussed in detail the inertial forces such as Gravitational, Coriolis-Lense-Thirring and Centrifugal forces in the Kerr-Newman Space-time in the Kerr-Newman Space-time. The main theme of this paper is to study the Gravitational and Centrifugal forces in the NUT-Kerr-Newman Space-time.Keywords: Gravitational Forces, Centrifugal Forces, Nut-Kerr-Newman, Space time.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12776512 Mobile Qibla and Prayer Time Finder using PDA and External Digital Compass
Authors: M.Z. Ibrahim, M.Z. Norashikin
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These days people love to travel around the world. Regardless of their location and time, they especially Muslims still need to perform their prayers. Normally for travelers, they need to bring maps, compass and for Muslim, they even have to bring Qibla pointer when they travel. It is slightly difficult to determine the Qibla direction and to know the time for each prayer. As the technology grows, many PDA equip with maps and GPS to locate their location. In this paper we present a new electronic device called Mobile Qibla and Prayer Time Finder to locate the Qibla direction and to determine each prayer time based on the current user-s location using PDA. This device use PIC microcontroller equipped with digital compass where it will communicate with PDA using Bluetooth technology and display the exact Qibla direction and prayer time automatically at any place in the world. This device is reliable and accurate in determining the Qibla direction and prayer time.Keywords: Bluetooth, digital compass, PDA, prayer time, Qibla.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20476511 Comparative Dielectric Properties of 1,2-Dichloroethane with n-Methylformamide and n,n-Dimethylformamide Using Time Domain Reflectometry Technique in Microwave Frequency
Authors: Shagufta Tabassum, V. P. Pawar, jr., G. N. Shinde
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The study of dielectric relaxation properties of polar liquids in the binary mixture has been carried out at 10, 15, 20 and 25 ºC temperatures for 11 different concentrations using time domain reflectometry technique. The dielectric properties of a solute-solvent mixture of polar liquids in the frequency range of 10 MHz to 30 GHz gives the information regarding formation of monomers and multimers and also an interaction between the molecules of the liquid mixture under study. The dielectric parameters have been obtained by the least squares fit method using the Debye equation characterized by a single relaxation time without relaxation time distribution.
Keywords: Excess properties, relaxation time, static dielectric constant, time domain refelectometry technique.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 5626510 Sensitivity Computations of Time Relaxation Model with an Application in Cavity Computation
Authors: Monika Neda, Elena Nikonova
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We present a numerical study of the sensitivity of the so called time relaxation family of models of fluid motion with respect to the time relaxation parameter χ on the two dimensional cavity problem. The goal of the study is to compute and compare the sensitivity of the model using finite difference method (FFD) and sensitivity equation method (SEM).
Keywords: Sensitivity, time relaxation, deconvolution, Navier- Stokes equations.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13216509 Robust BIBO Stabilization Analysis for Discrete-time Uncertain System
Authors: Zixin Liu, Shu Lü, Shouming Zhong, Mao Ye
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The discrete-time uncertain system with time delay is investigated for bounded input bounded output (BIBO). By constructing an augmented Lyapunov function, three different sufficient conditions are established for BIBO stabilization. These conditions are expressed in the form of linear matrix inequalities (LMIs), whose feasibility can be easily checked by using Matlab LMI Toolbox. Two numerical examples are provided to demonstrate the effectiveness of the derived results.
Keywords: Robust BIBO stabilization, delay-dependent stabilization, discrete-time system, time delay.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15806508 A Hyperexponential Approximation to Finite-Time and Infinite-Time Ruin Probabilities of Compound Poisson Processes
Authors: Amir T. Payandeh Najafabadi
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This article considers the problem of evaluating infinite-time (or finite-time) ruin probability under a given compound Poisson surplus process by approximating the claim size distribution by a finite mixture exponential, say Hyperexponential, distribution. It restates the infinite-time (or finite-time) ruin probability as a solvable ordinary differential equation (or a partial differential equation). Application of our findings has been given through a simulation study.Keywords: Ruin probability, compound Poisson processes, mixture exponential (hyperexponential) distribution, heavy-tailed distributions.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12726507 Diffusion Analysis of a Scalable Feistel Network
Authors: Subariah Ibrahim, Mohd Aizaini Maarof
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A generalization of the concepts of Feistel Networks (FN), known as Extended Feistel Network (EFN) is examined. EFN splits the input blocks into n > 2 sub-blocks. Like conventional FN, EFN consists of a series of rounds whereby at least one sub-block is subjected to an F function. The function plays a key role in the diffusion process due to its completeness property. It is also important to note that in EFN the F-function is the most computationally expensive operation in a round. The aim of this paper is to determine a suitable type of EFN for a scalable cipher. This is done by analyzing the threshold number of rounds for different types of EFN to achieve the completeness property as well as the number of F-function required in the network. The work focuses on EFN-Type I, Type II and Type III only. In the analysis it is found that EFN-Type II and Type III diffuses at the same rate and both are faster than Type-I EFN. Since EFN-Type-II uses less F functions as compared to EFN-Type III, therefore Type II is the most suitable EFN for use in a scalable cipher.
Keywords: Cryptography, Extended Feistel Network, Diffusion Analysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1703