Search results for: Mohammad Zaid
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 974

Search results for: Mohammad Zaid

734 Effect of Zinc Oxide Nanoparticles along with Sodium Hydroxide on Self-Cleaning and Antibacterial Properties of Polyethylene Terephthalate

Authors: Mohammad Mirjalili, Maryam Mohammdi, Loghman Karimi

Abstract:

In this study, synthesis of zinc oxide nanoparticles was carried out along with the hydrolysis of Polyethylene terephthalate using sodium hydroxide to increase the surface activity and enhance the nanoparticles adsorption. The polyester fabrics were treated with zinc acetate and sodium hydroxide at ultrasound bath, resulting in the formation of ZnO nanospheres. The presence of zinc oxide on the surface of the polyethylene terephthalate was confirmed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The self-cleaning property of treated polyethylene terephthalate was evaluated through discoloring methylene blue stain under sunlight irradiation. The antibacterial activities of the samples against two common pathogenic bacteria including Escherichia coli and Staphylococcus aureus were also assessed. The results indicated that the photocatalytic and antibacterial activities of the ultrasound treated polyethylene terephthalate improved significantly.

Keywords: zinc oxide, polyethylene terephthalate, self-cleaning, antibacterial

Procedia PDF Downloads 301
733 ERP Implementation in Iran: A Successful Experience in DGC

Authors: Mohammad Reza Ostad Ali Naghi Kashani

Abstract:

Nowadays, the amounts of companies which tend to have an Enterprise Resource Planning (ERP) application are increasing. Although ERP projects are expensive, time consuming, and complex, there are some successful experiences. These days, developing countries are striving to implement ERP projects successfully; however, there are many obstacles. Therefore, these projects would be failed or partially failed. This paper concerns the implementation of a successful ERP implementation, IFS, in Iran at Dana Geophysics Company (DGC). After a short review of ERP and ERP market in Iran, we propose a three phases deployment methodology (phase 1: Preparation and Business Process Management (BPM) phase 2: implementation and phase 3: testing, golive-1 (pilot) and golive-2 (final)). Then, we present five guidelines (Project Management, Change Management, Business Process Management (BPM), Training& Knowledge Management, and Technical Management), which were chose as work streams. In this case study we present lessons learned in Project management and Business process Management.

Keywords: business process management, critical success factors, ERP, project management

Procedia PDF Downloads 460
732 Experimental Determination of Aluminum 7075-T6 Parameters Using Stabilized Cycle Tests to Predict Thermal Ratcheting

Authors: Armin Rahmatfam, Mohammad Zehsaz, Farid Vakili Tahami, Nasser Ghassembaglou

Abstract:

In this paper the thermal ratcheting, kinematic hardening parameters C, γ, isotropic hardening parameters and also k, b, Q combined isotropic/kinematic hardening parameters have been obtained experimentally from the monotonic, strain controlled cyclic tests at room and elevated temperatures of 20°C, 100°C, and 400°C. These parameters are used in nonlinear combined isotropic/kinematic hardening model to predict better description of the loading and reloading cycles in the cyclic indentation as well as thermal ratcheting. For this purpose, three groups of specimens made of Aluminum 7075-T6 have been investigated. After each test and using stable hysteretic cycles, material parameters have been obtained for using in combined nonlinear isotropic/kinematic hardening models. Also the methodology of obtaining the correct kinematic/isotropic hardening parameters is presented.

Keywords: combined hardening model, kinematic hardening, isotropic hardening, cyclic tests

Procedia PDF Downloads 449
731 Static and Dynamic Analysis of Timoshenko Microcantilever Using the Finite Element Method

Authors: Mohammad Tahmasebipour, Hosein Salarpour

Abstract:

Micro cantilevers are one of the components used in the manufacture of micro-electromechanical systems. Epoxy microcantilevers have a variety of applications in the manufacture of micro-sensors and micro-actuators. In this paper, the Timoshenko Micro cantilever was statically and dynamically analyzed using the finite element method. First, all boundary conditions and initial conditions governing micro cantilevers were considered. The effect of size on the deflection, angle of rotation, natural frequencies, and mode shapes were then analyzed and evaluated under different frequencies. It was observed that an increased micro cantilever thickness reduces the deflection, rotation, and resonant frequency. A good agreement was observed between our results and those obtained by the couple stress theory, the classical theory, and the strain gradient elasticity theory.

Keywords: microcantilever, microsensor; epoxy, dynamic behavior, static behavior, finite element method

Procedia PDF Downloads 394
730 Human Talent Management: A Research Agenda

Authors: Mehraj Udin Ganaie, Mohammad Israrul Haque

Abstract:

The purpose of this paper is to enhance the theoretical and conceptual understanding of human talent management (HTM). With the help of extensive review of existing literature, we proposed a conceptual framework and few propositions to elucidate the influential relationship of competency focus, talent pooling, talent investment, and talenting orientation with value creation of a firm. It is believed that human talent management model will enhance the understanding of talent management orientation among practitioners and academicians. Practitioners will be able to align HTM orientation with business strategy wisely to yield better value for business (Shareholders, Employees, Owners, Customers, agents, and other stakeholders). Future research directions will explain how human talent management researchers will work on the integration of relationship and contribute towards the maturity of talent management by further exploring and validating the model empirically to enhance the body of knowledge.

Keywords: talent management orientation, competency focus, talent pooling, talent investment, talenting orientation

Procedia PDF Downloads 361
729 The Examination of Organizational DNA of General Directorate of Youth and Sport Organization of Fars Province Based on Hnald Model

Authors: Mehdi Rastegari Ghiri, Mohammad Reza Baradaran, Zahra Mirsanjari

Abstract:

The aim of the present study was the investigation of DNA Corporate General Administration of Sports and Youth in Fars province. The descriptive research method is a survey that was conducted by field survey. For data collection, questionnaires were used that designed based on Hnald and Silverman model. In this model the organizational DNA model is stated in four types: objective, individualistic, field-oriented and Spiritual. The reliability of the questionnaire by the researcher obtained by using Cronbach's alpha equal to 89/0 respectively. The statistical population includes all managers and specialists of Fars Province Directorate of Youth and Sport that 48 of them were selected as the samples of the research. The results showed the organizational DNA Directorate General for Youth and Sports Organization of Fars province has a field –oriented and nearly field-oriented DNA.

Keywords: organizational, DNA, Hnald, Silverman model

Procedia PDF Downloads 419
728 Epileptic Seizure Prediction Focusing on Relative Change in Consecutive Segments of EEG Signal

Authors: Mohammad Zavid Parvez, Manoranjan Paul

Abstract:

Epilepsy is a common neurological disorders characterized by sudden recurrent seizures. Electroencephalogram (EEG) is widely used to diagnose possible epileptic seizure. Many research works have been devoted to predict epileptic seizure by analyzing EEG signal. Seizure prediction by analyzing EEG signals are challenging task due to variations of brain signals of different patients. In this paper, we propose a new approach for feature extraction based on phase correlation in EEG signals. In phase correlation, we calculate relative change between two consecutive segments of an EEG signal and then combine the changes with neighboring signals to extract features. These features are then used to classify preictal/ictal and interictal EEG signals for seizure prediction. Experiment results show that the proposed method carries good prediction rate with greater consistence for the benchmark data set in different brain locations compared to the existing state-of-the-art methods.

Keywords: EEG, epilepsy, phase correlation, seizure

Procedia PDF Downloads 287
727 Imagology: The Study of Multicultural Imagery Reflected in the Heart of Elif Shafak’s 'The Bastard of Istanbul'

Authors: Mohammad Reza Haji Babai, Sepideh Ahmadkhan Beigi

Abstract:

Internationalization and modernization of the globe have played their roles in the process of cultural interaction between globalized societies and, consequently, found their way to the world of literature under the name of ‘imagology’. Imagology has made it possible for the reader to understand the author’s thoughts and judgments of others. The present research focuses on the intercultural images portrayed in the novel of a popular Turkish-French writer, Elif Shafak, about the lifestyle, traditions, habits, and social norms of Turkish, Americans, and Armenians. The novel seeks to articulate a more intricate multicultural memory of Turkishness by grieving over the Armenian massacre. This study finds that, as a mixture of multiple lifestyles and discourses, The Bastard of Istanbul reflects not only images of oriental culture but also occidental cultures. This means that the author has attempted to maintain selfhood through historical and cultural recollection, which resulted in constructing the self and another identity.

Keywords: imagology, Elif Shafak, The Bastard of Istanbul, self-image, other-image

Procedia PDF Downloads 117
726 Transmission Network Expansion Planning in Deregulated Power Systems to Facilitate Competition under Uncertainties

Authors: Hooshang Mohammad Alikhani, Javad Nikoukar

Abstract:

Restructuring and deregulation of power industry have changed the objectives of transmission expansion planning and increased the uncertainties. Due to these changes, new approaches and criteria are needed for transmission planning in deregulated power systems. The objective of this research work is to present a new approach for transmission expansion planning with considering new objectives and uncertainties in deregulated power systems. The approach must take into account the desires of all stakeholders in transmission expansion planning. Market based criteria must be defined to achieve the new objectives. Combination of market based criteria, technical criteria and economical criteria must be used for measuring the goodness of expansion plans to achieve market requirements, technical requirements, and economical requirements altogether.

Keywords: deregulated power systems, transmission network, stakeholder, energy systems

Procedia PDF Downloads 626
725 Evaluation of Coagulation State in Patients with End Stage Renal Disease (ESRD) by Thromboelastogram (TEG)

Authors: Mohammad Javad Esmaeili

Abstract:

Background: Coagulopathy is one of the complications with end stage renal disease with high prevalence in the world. Thromboelastogram is adynamic test for evaluation of coagulopathy and we have compared our patient's coagulation profiles with the results of TEG. Material and methods: In this study 50 patients with ESRD who were on regular hemodialysis for at least 6 months was selected with simple sampling and their coagulation profile was done with blood sampling and also TEG was done for every patient. Data were analyzed with SPSS and P<0.05 consider significant. Results: Protein s, Protein c and Antithrombin III deficiency was detected in 32%, 16% and 20% of patients and activated protein c resistance was abnormal in 2% of patients. In TEG, R time in 49% and K in 22/5% of patients was lower than normal and a-angle in 26% and maximum amplitude in 36% of patients was upper than normal (Hypercoagulable state). PS with R and ATIII with K have correlation. Conclusion: R time and K in TEG can be a suitable screening test in patients with suspicious to PS and ATIII deficiency.

Keywords: thromboelastography, chronic kidney disease, Coagulating disorder, hemodialysis

Procedia PDF Downloads 51
724 CFD Analysis of Solar Floor Radiant Heating System with ‎PCM

Authors: Mohammad Nazififard, Reihane Faghihi

Abstract:

This paper is aimed at understanding convective heat transfer of enclosed phase change material (PCM) in the solar and low-temperature hot water radiant floor heating geometry. In order to obtain the best performance of PCM, a radiant heating structure of the energy storage floor is designed which places heat pipes in the enclosed phase change material (PCM) layer, without concrete in it. The governing equations are numerically solved. The PCM thermal storage time is considered in relation to the floor surface temperature under different hot water temperatures. Moreover the PCM thermal storage time is numerically estimated under different supply water temperatures and flow rate. Results show the PCM floor heating system has a potential of making use of the daytime solar energy for heating at night efficiently.

Keywords: solar floor, heating system, phase change material, computational fluid dynamics

Procedia PDF Downloads 218
723 Anti-Language in Jordanian Spoken Arabic: A Sociolinguistic Perspective

Authors: Ahmad Mohammad Al-Harahsheh

Abstract:

Anti-language reflects anti-society; it is a restricted spoken code used among a group of interlocutors because of anti-society. This study aims to shed light on the sociolinguistic characteristics of anti-language used by prisoners in Jordan. The participants included were 15 male-Jordanian prisoners who have recently been released. The data were written, transliterated, and analyzed on the basis of sociolinguistics and discourse analysis. This study draws on sociolinguistic theory of language codes as the theoretical framework. The study concludes that anti-language is a male language and is used for secrecy, as the prisoners' tendency to protect themselves from the police; it is a verbal competition, contest and display. In addition, it is employed to express obnoxious ideas and acts by using more pleasant or blurred words and expressions. Also, the anti-language used by prisoners has six linguistic characteristics in JSA (Jordanian Spoken Arabic), such as relexicalization, neologism, rhyme formation, semantic change, derivation, and metaphorical expressions.

Keywords: anti-language, Jordanian Spoken Arabic, sociolinguistics, prisoners

Procedia PDF Downloads 341
722 How to Perform Proper Indexing?

Authors: Watheq Mansour, Waleed Bin Owais, Mohammad Basheer Kotit, Khaled Khan

Abstract:

Efficient query processing is one of the utmost requisites in any business environment to satisfy consumer needs. This paper investigates the various types of indexing models, viz. primary, secondary, and multi-level. The investigation is done under the ambit of various types of queries to which each indexing model performs with efficacy. This study also discusses the inherent advantages and disadvantages of each indexing model and how indexing models can be chosen based on a particular environment. This paper also draws parallels between various indexing models and provides recommendations that would help a Database administrator to zero-in on a particular indexing model attributed to the needs and requirements of the production environment. In addition, to satisfy industry and consumer needs attributed to the colossal data generation nowadays, this study has proposed two novel indexing techniques that can be used to index highly unstructured and structured Big Data with efficacy. The study also briefly discusses some best practices that the industry should follow in order to choose an indexing model that is apposite to their prerequisites and requirements.

Keywords: indexing, hashing, latent semantic indexing, B-tree

Procedia PDF Downloads 134
721 Imaging Based On Bi-Static SAR Using GPS L5 Signal

Authors: Tahir Saleem, Mohammad Usman, Nadeem Khan

Abstract:

GPS signals are used for navigation and positioning purposes by a diverse set of users. However, this project intends to utilize the reflected GPS L5 signals for location of target in a region of interest by generating an image that highlights the positions of targets in the area of interest. The principle of bi-static radar is used to detect the targets or any movement or changes. The idea is confirmed by the results obtained during MATLAB simulations. A matched filter based technique is employed in the signal processing to improve the system resolution. The simulation is carried out under different conditions with moving receiver and targets. Noise and attenuation is also induced and atmospheric conditions that affect the direct and reflected GPS signals have been simulated to generate a more practical scenario. A realistic GPS L5 signal has been simulated, the simulation results verify that the detection and imaging of targets is possible by employing reflected GPS using L5 signals and matched filter processing technique with acceptable spatial resolution.

Keywords: GPS, L5 Signal, SAR, spatial resolution

Procedia PDF Downloads 512
720 A Cost Effective Solar Powered Water Pump Solution for Household Application in the Rural Area of Bangladesh

Authors: Khosru M. Salim, Md. Jasim Uddin, Mohammad Rejwan Uddin

Abstract:

Developing countries like Bangladesh has huge population lives in the rural areas out of electricity. They are using manually operated tube well for collecting underground water to meet their daily demand. A human labour is required to lift water from tube well. Sometimes, it is impossible for a elementary school going child to operate a tube well in the school. Solar powered water pump could be a sustainable water pumping solution in the rural area of Bangladesh. To minimize the cost, a 0.5 horse power solar water pump is designed considering the requirement of water for a typical house hold in this research. A prototype of the 0.5 hp capacity system is implemented and tested in the rooftop of the university lab to validate the performances. Based on the experimental data, the performance of the system is analyzed and presented in this paper.

Keywords: water pump, solar photovoltaic module, performance analysis, feasibility study

Procedia PDF Downloads 282
719 A Model of Critical Consideration of Environmental Education: Concepts, Contexts, and Competencies

Authors: Mohammad Anwar, Hamid Ullah Khan, Shah Waliullah

Abstract:

Recently, environmental education is an essential element in avoiding environmental degradation around the globe that needs new articles and policymakers’ emphasis. Hence, the present article examines the impact of environmental education on environmental knowledge, environmental behavior, and environmental attitudes in Indonesia. The present research also investigated the moderating role of government support in environmental education, environmental knowledge, environmental behavior, and environmental attitude in Indonesia. A questionnaire was used as the primary data collection method. The smart PLS was utilized to test the association among variables and the hypotheses of the study. The results revealed that environmental education had a significant and positive linkage with environmental knowledge, environmental behavior, and environmental attitude in Indonesia. The findings also exposed that government support significantly moderated environmental education, environmental knowledge, and environmental behavior in Indonesia. The findings of this research would provide help to the policymakers in establishing the policies related to environmental education and reducing environmental degradation.

Keywords: environmental education, environmental knowledge, environmental behavior, environmental attitude, government support

Procedia PDF Downloads 68
718 Secure Intelligent Information Management by Using a Framework of Virtual Phones-On Cloud Computation

Authors: Mohammad Hadi Khorashadi Zadeh

Abstract:

Many new applications and internet services have been emerged since the innovation of mobile networks and devices. However, these applications have problems of security, management, and performance in business environments. Cloud systems provide information transfer, management facilities, and security for virtual environments. Therefore, an innovative internet service and a business model are proposed in the present study for creating a secure and consolidated environment for managing the mobile information of organizations based on cloud virtual phones (CVP) infrastructures. Using this method, users can run Android and web applications in the cloud which enhance performance by connecting to other CVP users and increases privacy. It is possible to combine the CVP with distributed protocols and central control which mimics the behavior of human societies. This mix helps in dealing with sensitive data in mobile devices and facilitates data management with less application overhead.

Keywords: BYOD, mobile cloud computing, mobile security, information management

Procedia PDF Downloads 285
717 The Effect of Conservative Tillage on Physical Properties of Soil and Yield of Rainfed Wheat

Authors: Abolfazl Hedayatipoor, Mohammad Younesi Alamooti

Abstract:

In order to study the effect of conservative tillage on a number of physical properties of soil and the yield of rainfed wheat, an experiment in the form of a randomized complete block design (RCBD) with three replications was conducted in a field in Aliabad County, Iran. The study treatments included: T1) Conventional method, T2) Combined moldboard plow method, T3) Chisel-packer method, and T4) Direct planting method. During early October, the study soil was prepared based on these treatments in a field which was used for rainfed wheat farming in the previous year. The apparent specific gravity of soil, weighted mean diameter (WMD) of soil aggregates, soil mechanical resistance, and soil permeability were measured. Data were analyzed in MSTAT-C. Results showed that the tillage practice had no significant effect on grain yield (p < 0.05). Soil permeability was 10.9, 16.3, 15.7 and 17.9 mm/h for T1, T2, T3 and T4, respectively.

Keywords: rainfed agriculture, conservative tillage, energy consumption, wheat

Procedia PDF Downloads 184
716 The Effect of Nitrogen Fertilizer Use Efficiency in Corn Yield and Yield Components in Cultivars KSC 704

Authors: Elham Bagherzadeh, Mohammad Fadaee, Rouhollah Keykhosravi

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In order to survey the nitrogen use efficiency in corn, the experimental plot in a randomized complete block design 2014 agricultural farm was Islamic Azad University of Karaj. The main factor was four levels of nitrogen fertilizer (respectively control, 150, 200 and 250 kg nitrogen fertilizer) and subplots consisted two levels of superabsorbent polymer Stockosorb (use, do not use). Analysis of variance is showed that different nitrogen levels and different superabsorbent of levels statistically significant. Comparisons average also showed there is a significant difference between use and non-use of superabsorbent. The results showed the interactions nitrogen and SAP by one percent level has a significant and effect on Fresh weight per plant, plant dry weight, biological yield, harvest index, cob diameter, cob dry weight, leaf width, leaf area were at the level of five percent statistical significant effect on Ear weight and grain yield.

Keywords: corn, nitrogen, comparison, biological yield

Procedia PDF Downloads 327
715 Factors Affecting the Critical Understanding of the Strategies Which Children Use to Motivate Parents in the Family Buying Process: Case of British Bangladeshi Children in the UK

Authors: Salma Akter, Mohammad M. Haque, Lawrence Akwetey

Abstract:

An empirical research design will analyze different factors/predictors children use to influence their parents in the family buying decision process in the unexplored area of British Bangladeshi children in the United Kingdom. The proposed conceptual model of factors- buying decision making process will be tested by the Structure Equation Model. A structured Questionnaire and secondary sources will employ to collect data and analyse and measure the validity by Statistical tools (SPSS) and Microsoft Excel. The Contemporary research aims to use the deductive approach developing the research questions and testing the hypothesis to identify the impact of different strategies British Bangladeshi children used to influence their parents in the family buying decision which was overlooked in the previous research.

Keywords: British Bangladeshi children, buying decision process, children influence, influential factors

Procedia PDF Downloads 242
714 Blockchain Technology in Supply Chain Management: A Systematic Review And Meta-Analysis

Authors: Mohammad Yousuf Khan, Bhavya Alankar

Abstract:

Blockchain is a promising technology with its features such as immutability and decentralized database. It has applications in various fields such as pharmaceutical, finance, & the food industry. At the core of its heart lies its feature, traceability which is the most desired key in supply chains. However, supply chains have always been hit rock bottom by scandals and controversies. In this review paper, we have explored the advancement and research gaps of blockchain technology (BT) in supply chain management (SCM). We have used the Prisma framework for systematic literature review (SLR) and included a minuscule amount of grey literature to reduce publication bias. We found that supply chain traceability and transparency is the most researched objective in SCM. There was hardly any research in supply chain resilience. Further, we found that 40 % of the papers were application based. Most articles have focused on the advantages of BT, rather than analyzing it critically. This study will help identify gaps and suitable actions to be followed for an efficient implementation of BT in SCM.

Keywords: blockchain technology, supply chain management, supply chain transparency, supply chain resilience

Procedia PDF Downloads 137
713 Formulating the Stochastic Finite Elements for Free Vibration Analysis of Plates with Variable Elastic Modulus

Authors: Mojtaba Aghamiri Esfahani, Mohammad Karkon, Seyed Majid Hosseini Nezhad, Reza Hosseini-Ara

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In this study, the effect of uncertainty in elastic modulus of a plate on free vibration response is investigated. For this purpose, the elastic modulus of the plate is modeled as stochastic variable with normal distribution. Moreover, the distance autocorrelation function is used for stochastic field. Then, by applying the finite element method and Monte Carlo simulation, stochastic finite element relations are extracted. Finally, with a numerical test, the effect of uncertainty in the elastic modulus on free vibration response of a plate is studied. The results show that the effect of uncertainty in elastic modulus of the plate cannot play an important role on the free vibration response.

Keywords: stochastic finite elements, plate bending, free vibration, Monte Carlo, Neumann expansion method.

Procedia PDF Downloads 365
712 The Effects of Different Doses of Caffeine on Young Futsal Players

Authors: Saead Rostami, Seyyed Hadi Hosseini Alavije, Aliakbar Torabi, Mohammad Bekhradi

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This study is about The effects of different doses of caffeine on young Futsal players. Young futsal players of selected ShahinShahr(a city in Esfahan province, Iran) team are sampled (24 people of 18.3±1.9 year- old). All players are members of youth team playing in Esfahan counties league. Having at least 5 years of experience, 2 practices and 1 match per week and lacking any limitation in the past 6 months are the most important requirements for sampling the players. Next, the study topic, its method, its uses, as ell possible risks are explained to the players. They signed a consent letter to take part in the study. Interest in the use of caffeine as an ergogenic aid has increased since the International Olympic Committee lifted the partial ban on its use. Caffeine has beneficial effects on various aspects of athletic performance, but its effects on training have been neglected. The purpose of this study was to investigate the acute effect of caffeine on testosterone and cortisole in young futsal players.

Keywords: anabolic, catabolic, performance, testosterone cortisol ratio, RAST test

Procedia PDF Downloads 320
711 The Potential of Dinar (Gold) Currency as the Main Object Transaction in Indonesia

Authors: Muhammad Ilham Agus Salim, Mohammad Ali

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In this article, we have elaborated a study over the nature of Islamic financial transaction by comparing between Dinar and IDR currency in Indonesia. We have found the interesting issue among scholars and practitioners in which Dinar would be a single currency ASEAN Economic Community (AEC), then becoming motivation and added value research. The assessment among dinar volatility analysis for three years ago and IDR fluctuation as well as outlook qualitative test regarding dinar are components of analysis that weak Indonesian currency should be altered to be better coinage. The value of dinar more stable than IDR and also eligible as a currency e.g. limited quantities, easy to carry, durable, easy to saved, and has the same quality. On the other hand, the existing of IDR has defeated by inflation. The EViews program explained that Dinar at current level still fluctuate, but in the first different have fixed variant. The result of analysis describing that dinar has potential as the medium exchange, because the material of dinar is relevant and feasible since 14 century until present. Therefore, dinar should be considered to solve Indonesia crisis today.

Keywords: medium of exchange, dinar & IDR currency, volatility analysis, EViews program

Procedia PDF Downloads 333
710 Analysis of Flow Dynamics of Heated and Cooled Pylon Upstream to the Cavity past Supersonic Flow with Wall Heating and Cooling

Authors: Vishnu Asokan, Zaid M. Paloba

Abstract:

Flow over cavities is an important area of research due to the significant change in flow physics caused by cavity aspect ratio, free stream Mach number and the nature of upstream boundary layer approaching the cavity leading edge. Cavity flow finds application in aircraft wheel well, weapons bay, combustion chamber of scramjet engines, etc. These flows are highly unsteady, compressible and turbulent and it involves mass entrainment coupled with acoustics phenomenon. Variation of flow dynamics in an angled cavity with a heated and cooled pylon upstream to the cavity with spatial combinations of heat flux addition and removal to the wall studied numerically. The goal of study is to investigate the effect of energy addition, removal to the cavity walls and pylon cavity flow dynamics. Preliminary steady state numerical simulations on inclined cavities with heat addition have shown that wall pressure profiles, as well as the recirculation, are influenced by heat transfer to the compressible fluid medium. Such a hybrid control of cavity flow dynamics in the form of heat transfer and pylon geometry can open out greater opportunities in enhancement of mixing and flame holding requirements of supersonic combustors. Addition of pylon upstream to the cavity reduces the acoustic oscillations emanating from the geometry. A numerical unsteady analysis of supersonic flow past cavities exposed to cavity wall heating and cooling with heated and cooled pylon helps to get a clear idea about the oscillation suppression in the cavity. A Cavity of L/D 4 and aft wall angle 22 degree with an upstream pylon of h/D=1.5 mm with a wall angle 29 degree exposed to supersonic flow of Mach number 2 and heat flux of 40 W/cm² and -40 W/cm² modeled for the above study. In the preliminary study, the domain is modeled and validated numerically with a turbulence model of SST k-ω using an HLLC implicit scheme. Both qualitative and quantitative flow data extracted and analyzed using advanced CFD tools. Flow visualization is done using numerical Schlieren method as the fluid medium gives the density variation. The heat flux addition to the wall increases the secondary vortex size of the cavity and removal of energy leads to the reduction in vortex size. The flow field turbulence seems to be increasing at higher heat flux. The shear layer thickness increases as heat flux increases. The steady state analysis of wall pressure shows that there is variation on wall pressure as heat flux increases. Shift in frequency of unsteady wall pressure analysis is an interesting observation for the above study. The time averaged skin friction seems to be reducing at higher heat flux due to the variation in viscosity of fluid inside the cavity.

Keywords: energy addition, frequency shift, Numerical Schlieren, shear layer, vortex evolution

Procedia PDF Downloads 120
709 Vibration Control of a Functionally Graded Carbon Nanotube-Reinforced Composites Beam Resting on Elastic Foundation

Authors: Gholamhosein Khosravi, Mohammad Azadi, Hamidreza Ghezavati

Abstract:

In this paper, vibration of a nonlinear composite beam is analyzed and then an active controller is used to control the vibrations of the system. The beam is resting on a Winkler-Pasternak elastic foundation. The composite beam is reinforced by single walled carbon nanotubes. Using the rule of mixture, the material properties of functionally graded carbon nanotube-reinforced composites (FG-CNTRCs) are determined. The beam is cantilever and the free end of the beam is under follower force. Piezoelectric layers are attached to the both sides of the beam to control vibrations as sensors and actuators. The governing equations of the FG-CNTRC beam are derived based on Euler-Bernoulli beam theory Lagrange- Rayleigh-Ritz method. The simulation results are presented and the effects of some parameters on stability of the beam are analyzed.

Keywords: carbon nanotubes, vibration control, piezoelectric layers, elastic foundation

Procedia PDF Downloads 244
708 Automatic Facial Skin Segmentation Using Possibilistic C-Means Algorithm for Evaluation of Facial Surgeries

Authors: Elham Alaee, Mousa Shamsi, Hossein Ahmadi, Soroosh Nazem, Mohammad Hossein Sedaaghi

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Human face has a fundamental role in the appearance of individuals. So the importance of facial surgeries is undeniable. Thus, there is a need for the appropriate and accurate facial skin segmentation in order to extract different features. Since Fuzzy C-Means (FCM) clustering algorithm doesn’t work appropriately for noisy images and outliers, in this paper we exploit Possibilistic C-Means (PCM) algorithm in order to segment the facial skin. For this purpose, first, we convert facial images from RGB to YCbCr color space. To evaluate performance of the proposed algorithm, the database of Sahand University of Technology, Tabriz, Iran was used. In order to have a better understanding from the proposed algorithm; FCM and Expectation-Maximization (EM) algorithms are also used for facial skin segmentation. The proposed method shows better results than the other segmentation methods. Results include misclassification error (0.032) and the region’s area error (0.045) for the proposed algorithm.

Keywords: facial image, segmentation, PCM, FCM, skin error, facial surgery

Procedia PDF Downloads 558
707 Development Planning in the System of the Islamic Republic of Iran in the Light of Development Laws: From Rationally Planning to Wisely Decision Making

Authors: Mohammad Sadeghi, Mahdieh Saniee

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Nowadays, development laws have become a major branch of engineering science, laws help humankind achieve his/her basic needs, and it is attracted to the attention of the nations. Therefore, lawyers have been invited to contemplate legislator's approaches respecting legislating countries' economic, social and cultural development plans and to observe the reliance of approaches on two elements of distributive justice and transitional justice in light of legal rationality. Legal rationality in development planning has encountered us with this question that whether a rational approach and existing models in the Iran development planning system approximate us to the goal of development laws respecting the rationalist approach and also regarding wisely decision-making model. The present study will investigate processes, approaches, and damages of development planning in the legislation of country development plans to answer this question.

Keywords: rationality, decision-making process, policymaking, development

Procedia PDF Downloads 89
706 Chaos Cryptography in Cloud Architectures with Lower Latency

Authors: Mohammad A. Alia

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With the rapid evolution of the internet applications, cloud computing becomes one of today’s hottest research areas due to its ability to reduce costs associated with computing. Cloud is, therefore, increasing flexibility and scalability for computing services in the internet. Cloud computing is Internet based computing due to shared resources and information which are dynamically delivered to consumers. As cloud computing share resources via the open network, hence cloud outsourcing is vulnerable to attack. Therefore, this paper will explore data security of cloud computing by implementing chaotic cryptography. The proposal scenario develops a problem transformation technique that enables customers to secretly transform their information. This work proposes the chaotic cryptographic algorithms have been applied to enhance the security of the cloud computing accessibility. However, the proposed scenario is secure, easy and straightforward process. The chaotic encryption and digital signature systems ensure the security of the proposed scenario. Though, the choice of the key size becomes crucial to prevent a brute force attack.

Keywords: chaos, cloud computing, security, cryptography

Procedia PDF Downloads 317
705 Human Intraocular Thermal Field in Action with Different Boundary Conditions Considering Aqueous Humor and Vitreous Humor Fluid Flow

Authors: Dara Singh, Keikhosrow Firouzbakhsh, Mohammad Taghi Ahmadian

Abstract:

In this study, a validated 3D finite volume model of human eye is developed to study the fluid flow and heat transfer in the human eye at steady state conditions. For this purpose, discretized bio-heat transfer equation coupled with Boussinesq equation is analyzed with different anatomical, environmental, and physiological conditions. It is demonstrated that the fluid circulation is formed as a result of thermal gradients in various regions of eye. It is also shown that posterior region of the human eye is less affected by the ambient conditions compared to the anterior segment which is sensitive to the ambient conditions and also to the way the gravitational field is defined compared to the geometry of the eye making the circulations and the thermal field complicated in transient states. The effect of variation in material and boundary conditions guides us to the conclusion that thermal field of a healthy and non-healthy eye can be distinguished via computer simulations.

Keywords: bio-heat, boussinesq, conduction, convection, eye

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