Search results for: Economic Order Policy
3472 Implementing Fault Tolerance with Proxy Signature on the Improvement of RSA System
Authors: H. El-Kamchouchi, Heba Gaber, Fatma Ahmed, Dalia H. El-Kamchouchi
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Fault tolerance and data security are two important issues in modern communication systems. During the transmission of data between the sender and receiver, errors may occur frequently. Therefore, the sender must re-transmit the data to the receiver in order to correct these errors, which makes the system very feeble. To improve the scalability of the scheme, we present a proxy signature scheme with fault tolerance over an efficient and secure authenticated key agreement protocol based on the improved RSA system. Authenticated key agreement protocols have an important role in building a secure communications network between the two parties.
Keywords: Proxy signature, fault tolerance, improved RSA, key agreement.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12583471 Design of AC Electronics Load Surge Protection
Authors: N. Mungkung, S. Wongcharoen, C. Sukkongwari, Somchai Arunrungrasmi
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This study examines the design and construction of AC Electronics load surge protection in order to carry electric surge load arisen from faults in low voltage electricity system (single phase/220V) by using the principle of electronics load clamping voltage during induction period so that electric voltage could go through to safe load and continue to work. The qualification of the designed device could prevent both transient over voltage and voltage swell. Both will work in cooperation, resulting in the ability to improve and modify the quality of electrical power in Thailand electricity distribution system more effective than the past and help increase the lifetime of electric appliances, electric devices, and electricity protection equipments.Keywords: Electronics Load, Transient Over Voltage, Voltage Swell.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26733470 Production of Biodiesel from Roasted Chicken Fat and Methanol: Free Catalyst
Authors: Jorge Ramírez-Ortiz, Merced Martínez Rosales, Horacio Flores Zúñiga
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Transesterification reactions free of catalyst between roasted chicken fat with methanol were carried out in a batch reactor in order to produce biodiesel to temperatures from 120°C to 140°C. Parameters related to the transesterification reactions, including temperature, time and the molar ratio of chicken fat to methanol also investigated. The maximum yield of the reaction was of 98% under conditions of 140°C, 4 h of reaction time and a molar ratio of chicken fat to methanol of 1:31. The biodiesel thus obtained exhibited a viscosity of 6.3 mm2/s and a density of 895.9 kg/m3. The results showed this process can be right choice to produce biodiesel since this process does not use any catalyst. Therefore, the steps of neutralization and washing are avoided, indispensables in the case of the alkaline catalysis.
Keywords: Biodiesel, non-catalyst, roasted chicken fat, transesterification.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 31583469 Ion-Acoustic Double Layer in a Plasma with Two- Temperature Nonisothermal Electrons and Charged Dust Grains
Authors: Basudev Ghosh, Sreyasi Banerjee
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Using the pseudopotential technique the Sagdeev potential equation has been derived in a plasma consisting of twotemperature nonisothermal electrons, negatively charged dust grains and warm positive ions. The study shows that the presence of nonisothermal two-temperature electrons and charged dust grains have significant effects on the excitation and structure of the ionacoustic double layers in the model plasma under consideration. Only compressive type double layer is obtained in the present plasma model. The double layer solution has also been obtained by including higher order nonlinearity and nonisothermality, which is shown to modify the amplitude and deform the shape of the double layer.
Keywords: Two temperature non-isothermal electrons and charged dust grains.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 32053468 Business Process Orientation: Case of Croatia
Authors: Ljubica Milanović Glavan
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Because of the increasing business pressures, companies must be adaptable and flexible in order to withstand them. Inadequate business processes and low level of business process orientation, that in its core accentuates business processes as opposed to business functions and focuses on process performance and customer satisfaction, hider the ability to adapt to changing environment. It has been shown in previous studies that the companies which have reached higher business process maturity level consistently outperform those that have not reached them. The aim of this paper is to provide a basic understanding of business process orientation concept and business process maturity model. Besides that the paper presents the state of business process orientation in Croatia that has been captured with a study conducted in 2013. Based on the results some practical implications and guidelines for managers are given.
Keywords: Business process orientation, business process maturity, Croatia, maturity score.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16793467 “The Social Destination“: How Social Media Influences the Organisational Structure and Leadership of DMOs
Authors: Mihaela Jucan, Cornel Jucan, Ilie Rotariu
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The paper deals with the most important changes that have occurred in business because of social media and its impact on organisations and leadership in recent years. It seeks to synthesize existing research, theories and concepts, in order to understand "social destinations", and to provide a bridge from past research to future success. Becoming a "social destination" is a strategic and tactical leadership and management issue and the paper will present the importance of destination leadership in choosing the way towards a social destination and some organisational models. It also presents some social media tools that can be used in transforming a destination into a social one. Adapting organisations to the twentyfirst century means adopting social media as a way of life and a way of business.
Keywords: Business, destination, leadership, organization, social.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 41513466 Cooperative CDD Scheme Based on Hierarchical Modulation in OFDM System
Authors: Seung-Jun Yu, Yeong-Seop Ahn, Young-Min Ko, Hyoung-Kyu Song
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In order to achieve high data rate and increase the spectral efficiency, multiple input multiple output (MIMO) system has been proposed. However, multiple antennas are limited by size and cost. Therefore, recently developed cooperative diversity scheme, which profits the transmit diversity only with the existing hardware by constituting a virtual antenna array, can be a solution. However, most of the introduced cooperative techniques have a common fault of decreased transmission rate because the destination should receive the decodable compositions of symbols from the source and the relay. In this paper, we propose a cooperative cyclic delay diversity (CDD) scheme that use hierarchical modulation. This scheme is free from the rate loss and allows seamless cooperative communication.Keywords: MIMO, Cooperative communication, CDD, Hierarchical modulation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21973465 Underwriting Risks as Determinants of Insurance Cycles: Case of Croatia
Authors: D. Jakovčević, M. Mihelja Žaja
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The purpose of this paper is to analyze the influence and relative share of underwriting risks in explaining the variation in insurance cycles in subsequent periods. Through the insurance contracts they underwrite, insurance companies assume risks. Underwriting risks include pricing risk, reserve risk, reinsurance risk and occurrence risk. These risks pose major risks for property and liability insurers, and therefore their impact on the insurance cycle is important. The main goal of this paper is to determine the relative proportion of underwriting risks in explaining the variation of insurance cycle. In order to fulfill the main goal of the paper vector autoregressive model, VAR, will be applied.
Keywords: Insurance cycle, insurance risks, combined ratio, Republic of Croatia.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 38393464 A Comparative Study on Eastern and Western Wedding Ceremonies in Korean Films and Hollywood Films
Authors: Timothy Yoonsuk Lee, Joonhyoup Lee, Yoojin Chung
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As an adult man and woman love each other and come to have faith in each other as their spouse, they marry each other. Recently people-s economic life has become individualized and women are enjoying a high education level and increased participation in social activities, and these changes are creating environment favorable for single life. Thus, an increasing number of people are choosing celibacy, and many people prefer cohabitation to marriage. Nevertheless, marriage is still regarded as a must-to-do in our thought. Most of people throughout the world admit marriage as one of natural processes of life, and is an important passage rite in life that all people experience as we can see everywhere in the world despite the diversity of lifestyles. With regard to wedding ceremony, however, each country and culture has its own unique tradition and style of festival. It is not just a congratulatory ceremony but contains multiple concepts representing the age, country or culture. Moreover, the form and contents of wedding ceremony changes over time, and such features of wedding ceremony are well represented in films. This study took note of the fact that films reflect and reproduce each country-s historicity, culturality and analyzed four films, which are believed to show differences between Eastern and Western wedding ceremonies. The selected films are: A Perfect Match (2002), Marriage Is a Crazy Thing (2001), Bride Wars (2009) and 27 Dresses (2008). The author attempted to examine wedding ceremonies described in the four films, differences between the East and the West suggested by the films, and changes in their societies.
Keywords: Wedding ceremony, Korean films, Hollywood films, semiotics
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 42213463 Iterative Way to Acquire Information Technology for Defense and Aerospace
Authors: Ahmet Denker, Hakan Gürkan
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Defense and Aerospace environment is continuously striving to keep up with increasingly sophisticated Information Technology (IT) in order to remain effective in today-s dynamic and unpredictable threat environment. This makes IT one of the largest and fastest growing expenses of Defense. Hundreds of millions of dollars spent a year on IT projects. But, too many of those millions are wasted on costly mistakes. Systems that do not work properly, new components that are not compatible with old ones, trendy new applications that do not really satisfy defense needs or lost through poorly managed contracts. This paper investigates and compiles the effective strategies that aim to end exasperation with low returns and high cost of Information Technology acquisition for defense; it tries to show how to maximize value while reducing time and expenditure.Keywords: Iterative process, acquisition management, project management, software economics, requirement analysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14003462 Septic B-spline Collocation Method for Solving One-dimensional Hyperbolic Telegraph Equation
Authors: Marzieh Dosti, Alireza Nazemi
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Recently, it is found that telegraph equation is more suitable than ordinary diffusion equation in modelling reaction diffusion for such branches of sciences. In this paper, a numerical solution for the one-dimensional hyperbolic telegraph equation by using the collocation method using the septic splines is proposed. The scheme works in a similar fashion as finite difference methods. Test problems are used to validate our scheme by calculate L2-norm and L∞-norm. The accuracy of the presented method is demonstrated by two test problems. The numerical results are found to be in good agreement with the exact solutions.
Keywords: B-spline, collocation method, second-order hyperbolic telegraph equation, difference schemes.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17973461 The Effect of the Direct Contact Heat Exchanger on Steam Power Plant
Authors: Mohamed A. Elhaj, Salahedin A. Aljahime
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An actual power plant, which is the power plant of Iron and Steel Factory at Misurata city in Libya , has been modeled using Matlab in order to compare its results to the actual results of the actual cycle. This paper concentrates on two factors: a- The comparison between exergy losses in the actual cycle and the modeled cycle. b- The effect of extracting pressure on temperature water at boiler inlet. Closed heat exchangers used in this plant have been substituted by open heat exchangers in the current study of the modeled power plant and the required changes in the pressure have been considered. In the following investigation the two points mentioned above are taken in consideration.Keywords: Steam Power Plant, Contact Heat exchanger, Exergy, Cycle Efficiency.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13663460 New Approaches on Exponential Stability Analysis for Neural Networks with Time-Varying Delays
Authors: Qingqing Wang, Baocheng Chen, Shouming Zhong
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In this paper, utilizing the Lyapunov functional method and combining linear matrix inequality (LMI) techniques and integral inequality approach (IIA) to study the exponential stability problem for neural networks with discrete and distributed time-varying delays.By constructing new Lyapunov-Krasovskii functional and dividing the discrete delay interval into multiple segments,some new delay-dependent exponential stability criteria are established in terms of LMIs and can be easily checked.In order to show the stability condition in this paper gives much less conservative results than those in the literature,numerical examples are considered.
Keywords: Neural networks, Exponential stability, LMI approach, Time-varying delays.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20653459 IT/IS Outsourcing Relationship Factors in Higher Education Institution: Behavioral Dimensions from Client Perspectives
Authors: Nor Aziati Abdul Hamid, Rajeev SuberamanyNor Aziati Abdul Hamid, Rajeev Suberamany
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Higher education institutions are increasingly opting to outsourcing methods in order to sustain themselves and this creates a gap of literature in terms of how they perceive the relationship. This research paper attempts to identify the behavioral and psychological factors that exist in the engagement thus providing valuable information to practicing and potential clients, and vendors. The determinants were gathered from previous literatures and analyzed to formulate the factors. This study adopts the case study and survey approaches in which interviews and questionnaires are deployed on employees of IT-related department in a Malaysian higher education institution.
Keywords: Higher education institution, information technology, outsourcing, relationship
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20863458 Analysis of Causality between Defect Causes Using Association Rule Mining
Authors: Sangdeok Lee, Sangwon Han, Changtaek Hyun
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Construction defects are major components that result in negative impacts on project performance including schedule delays and cost overruns. Since construction defects generally occur when a few associated causes combine, a thorough understanding of defect causality is required in order to more systematically prevent construction defects. To address this issue, this paper uses association rule mining (ARM) to quantify the causality between defect causes, and social network analysis (SNA) to find indirect causality among them. The suggested approach is validated with 350 defect instances from concrete works in 32 projects in Korea. The results show that the interrelationships revealed by the approach reflect the characteristics of the concrete task and the important causes that should be prevented.Keywords: Causality, defect causes, social network analysis, association rule mining.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13373457 Thermomechanical Damage Modeling of F114 Carbon Steel
Authors: A. El Amri, M. El Yakhloufi Haddou, A. Khamlichi
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The numerical simulation based on the Finite Element Method (FEM) is widely used in academic institutes and in the industry. It is a useful tool to predict many phenomena present in the classical manufacturing forming processes such as fracture. But, the results of such numerical model depend strongly on the parameters of the constitutive behavior model. The influences of thermal and mechanical loads cause damage. The temperature and strain rate dependent materials’ properties and their modelling are discussed. A Johnson-Cook Model of damage has been selected for the numerical simulations. Virtual software called the ABAQUS 6.11 is used for finite element analysis. This model was introduced in order to give information concerning crack initiation during thermal and mechanical loads.
Keywords: Thermomechanical fatigue, failure, numerical simulation, fracture, damages.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14953456 Decision Framework for Cross-Border Railway Infrastructure Projects
Authors: Dimitrios J. Dimitriou, Maria F. Sartzetaki
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Transport infrastructure assets are key components of the national asset portfolio. The decision to invest in a new infrastructure in transports could take from a few years to some decades. This is mainly because of the need to reserve and spent many capitals, the long payback period, the number of the stakeholders involved in decision process and –many times- the investment and business risks are high. Therefore, the decision assessment framework is an essential challenge linked with the key decision factors meet the stakeholder expectations highlighting project trade-offs, financial risks, business uncertainties and market limitations. This paper examines the decision process for new transport infrastructure projects in cross border regions, where a wide range of stakeholders with different expectation is involved. According to a consequences analysis systemic approach, the relationship of transport infrastructure development, economic system development and stakeholder expectation is analyzed. Adopting the on system of system methodological approach, the decision making framework, variables, inputs and outputs are defined, highlighting the key shareholder’s role and expectations. The application provides the methodology outputs presenting the proposed decision framework for a strategic railway project in north Greece deals with the upgrade of the existing railway corridor connecting Greece, Turkey and Bulgaria.
Keywords: System of system approach, decision making, cross-border, infrastructure project.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18023455 Classification of Defects by the SVM Method and the Principal Component Analysis (PCA)
Authors: M. Khelil, M. Boudraa, A. Kechida, R. Drai
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Analyses carried out on examples of detected defects echoes showed clearly that one can describe these detected forms according to a whole of characteristic parameters in order to be able to make discrimination between a planar defect and a volumic defect. This work answers to a problem of ultrasonics NDT like Identification of the defects. The problems as well as the objective of this realized work, are divided in three parts: Extractions of the parameters of wavelets from the ultrasonic echo of the detected defect - the second part is devoted to principal components analysis (PCA) for optimization of the attributes vector. And finally to establish the algorithm of classification (SVM, Support Vector Machine) which allows discrimination between a plane defect and a volumic defect. We have completed this work by a conclusion where we draw up a summary of the completed works, as well as the robustness of the various algorithms proposed in this study.Keywords: NDT, PCA, SVM, ultrasonics, wavelet
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20033454 Feasibility Study of the Quadcopter Propeller Vibrations for the Energy Production
Authors: Nneka Osuchukwu, Leonid Shpanin
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The concept of converting the kinetic energy of quadcopter propellers into electrical energy is considered in this contribution following the feasibility study of the propeller vibrations, theoretical energy conversion, and simulation techniques. Analysis of the propeller vibration performance is presented via graphical representation of calculated and simulated parameters, in order to demonstrate the possibility of recovering the harvested energy from the propeller vibrations of the quadcopter while the quadcopter is in operation. Consideration of using piezoelectric materials in such concept, converting the mechanical energy of the propeller into the electrical energy, is given. Photographic evidence of the propeller in operation is presented and discussed together with experimental results to validate the theoretical concept.Keywords: Unmanned aerial vehicle, energy harvesting, piezoelectric material, propeller vibration.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16893453 Design of Nonlinear Observer by Using Chebyshev Interpolation based on Formal Linearization
Authors: Kazuo Komatsu, Hitoshi Takata
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This paper discusses a design of nonlinear observer by a formal linearization method using an application of Chebyshev Interpolation in order to facilitate processes for synthesizing a nonlinear observer and to improve the precision of linearization. A dynamic nonlinear system is linearized with respect to a linearization function, and a measurement equation is transformed into an augmented linear one by the formal linearization method which is based on Chebyshev interpolation. To the linearized system, a linear estimation theory is applied and a nonlinear observer is derived. To show effectiveness of the observer design, numerical experiments are illustrated and they indicate that the design shows remarkable performances for nonlinear systems.Keywords: nonlinear system, nonlinear observer, formal linearization, Chebyshev interpolation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15943452 Reliability Analysis of k-out-of-n : G System Using Triangular Intuitionistic Fuzzy Numbers
Authors: Tanuj Kumar, Rakesh Kumar Bajaj
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In the present paper, we analyze the vague reliability of k-out-of-n : G system (particularly, series and parallel system) with independent and non-identically distributed components, where the reliability of the components are unknown. The reliability of each component has been estimated using statistical confidence interval approach. Then we converted these statistical confidence interval into triangular intuitionistic fuzzy numbers. Based on these triangular intuitionistic fuzzy numbers, the reliability of the k-out-of-n : G system has been calculated. Further, in order to implement the proposed methodology and to analyze the results of k-out-of-n : G system, a numerical example has been provided.
Keywords: Vague set, vague reliability, triangular intuitionistic fuzzy number, k-out-of-n : G system, series and parallel system.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 29823451 The Role of Identifications in Women Psychopathology
Authors: Mary Gouva, Elena Dragioti, Evangelia Kotrsotsiou
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Family identification has the potential to play a very decisive role in psychopathology. In this study we aimed to investigate the impact of family identifications on female psychopathology. A community sample of 101 women (mean age 20.81 years, SD = 0.91 ranged 20-25) participated to the present study. The girls completed a) the Symptom Check-List Revised (SCL-90) and b) questionnaire concerning socio-demographic information and questions for family identifications. The majority of women reported that they matched to the father in terms of identifications (47.1%). Age and birth order were not contributed on family identifications (F(5) =2.188, p=.062 and F(3)=1.244, p=.299 respectively). Multivariate analysis by using MANCOVA found statistical significant associations between family identifications and domains of psychopathology as provided by SCL-90 (P<05). Our results highlight the role of identifications especially on father and female psychopathology as well as replicate the Freudian perception about the female Oedipus complex.
Keywords: Family Identification, Psychoanalysis, Psychopathology, Women.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17723450 Measurements of Radial Velocity in Fixed Fluidized Bed for Fischer-Tropsch Synthesis Using LDV
Authors: Xiaolai Zhang, Haitao Zhang, Qiwen Sun, Weixin Qian, Weiyong Ying
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High temperature Fischer-Tropsch synthesis process use fixed fluidized bed as a reactor. In order to understand the flow behavior in the fluidized bed better, the research of how the radial velocity affects the entire flow field is necessary. Laser Doppler Velocimetry (LDV) was used to study the radial velocity distribution along the diameter direction of the cross-section of the particle in a fixed fluidized bed. The velocity in the cross-section is fluctuating within a small range. The direction of the speed is a random phenomenon. In addition to r/R is 1, the axial velocity are more than 6 times of the radial velocity, the radial velocity has little impact on the axial velocity in a fixed fluidized bed.Keywords: LDV, fixed fluidized bed, velocity, Fischer-Tropsch synthesis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16283449 Towards Cloud Computing Anatomy
Authors: Maria Salama, Mohamed Kouta
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Cloud Computing has recently emerged as a compelling paradigm for managing and delivering services over the internet. The rise of Cloud Computing is rapidly changing the landscape of information technology, and ultimately turning the longheld promise of utility computing into a reality. As the development of Cloud Computing paradigm is speedily progressing, concepts, and terminologies are becoming imprecise and ambiguous, as well as different technologies are interfering. Thus, it becomes crucial to clarify the key concepts and definitions. In this paper, we present the anatomy of Cloud Computing, covering its essential concepts, prominent characteristics, its affects, architectural design and key technologies. We differentiate various service and deployment models. Also, significant challenges and risks need are tackled in order to guarantee the long-term success of Cloud Computing. The aim of this paper is to provide a better understanding of the anatomy of Cloud Computing and pave the way for further research in this area.Keywords: Anatomy, Aspects, Cloud Computing, Challenges.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19843448 Account Management Method with Blind Signature Scheme
Authors: Ryu Watanabe, Yutaka Miyake
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Reducing the risk of information leaks is one of the most important functions of identity management systems. To achieve this purpose, Dey et al. have already proposed an account management method for a federated login system using a blind signature scheme. In order to ensure account anonymity for the authentication provider, referred to as an IDP (identity provider), a blind signature scheme is utilized to generate an authentication token on an authentication service and the token is sent to an IDP. However, there is a problem with the proposed system. Malicious users can establish multiple accounts on an IDP by requesting such accounts. As a measure to solve this problem, in this paper, the authors propose an account checking method that is performed before account generation.Keywords: identity management, blind signature, privacy protection
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15443447 Image Thresholding for Weld Defect Extraction in Industrial Radiographic Testing
Authors: Nafaâ Nacereddine, Latifa Hamami, Djemel Ziou
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In non destructive testing by radiography, a perfect knowledge of the weld defect shape is an essential step to appreciate the quality of the weld and make decision on its acceptability or rejection. Because of the complex nature of the considered images, and in order that the detected defect region represents the most accurately possible the real defect, the choice of thresholding methods must be done judiciously. In this paper, performance criteria are used to conduct a comparative study of thresholding methods based on gray level histogram, 2-D histogram and locally adaptive approach for weld defect extraction in radiographic images.
Keywords: 1D and 2D histogram, locally adaptive approach, performance criteria, radiographic image, thresholding, weld defect.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23433446 Finite Element and Subspace Identification Approaches to Model Development of a Smart Acoustic Box with Experimental Verification
Authors: Tamara Nestorović, Jean Lefèvre, Stefan Ringwelski, Ulrich Gabbert
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Two approaches for model development of a smart acoustic box are suggested in this paper: the finite element (FE) approach and the subspace identification. Both approaches result in a state-space model, which can be used for obtaining the frequency responses and for the controller design. In order to validate the developed FE model and to perform the subspace identification, an experimental set-up with the acoustic box and dSPACE system was used. Experimentally obtained frequency responses show good agreement with the frequency responses obtained from the FE model and from the identified model.
Keywords: Acoustic box, experimental verification, finite element model, subspace identification.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15623445 Energy Separation Mechanism in Uni-Flow Vortex Tube Using Compressible Vortex Flow
Authors: Hiroshi Katanoda, Mohd Hazwan bin Yusof
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A theoretical investigation from the view point of gas-dynamics and thermodynamics was carried out, in order to clarify the energy separation mechanism in a viscous compressible vortex, as a primary flow element in a uni-flow vortex tube. The mathematical solutions of tangential velocity, density and temperature in a viscous compressible vortical flow were used in this study.It is clear that a total temperature in the vortex core falls well below that distant from the vortex core in the radial direction, causing aregion with higher total temperature,compared to the distant region,peripheral to the vortex core.
Keywords: Energy separation mechanism, theoretical analysis, vortex tube, vortical flow.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19043444 Study on Specific Energy in Grinding of DRACs: A Response Surface Methodology Approach
Authors: Dayananda Pai, Shrikantha S. Rao, Savitha G.Kini
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In this study, the effects of machining parameters on specific energy during surface grinding of 6061Al-SiC35P composites are investigated. Vol% of SiC, feed and depth of cut were chosen as process variables. The power needed for the calculation of the specific energy is measured from the two watt meter method. Experiments are conducted using standard RSM design called Central composite design (CCD). A second order response surface model was developed for specific energy. The results identify the significant influence factors to minimize the specific energy. The confirmation results demonstrate the practicability and effectiveness of the proposed approach.Keywords: ANOVA, Metal matrix composites, Response surface methodology, Specific energy, Two watt meter method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22663443 Exact Analysis of Resonance Frequencies of Simply Supported Cylindrical Shells
Authors: A. Farshidianfar, P. Oliazadeh, M. H. Farshidianfar
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In order to study the free vibration of simply supported circular cylindrical shells; an analytical procedure is developed and discussed in detail. To identify its’ validity, the exact technique was applied to four different shell theories 1) Soedel, 2) Flugge, 3) Morley-Koiter, and 4) Donnell. The exact procedure was compared favorably with experimental results and those obtained using the numerical finite element method. A literature review reveals that beam functions are used extensively as an approximation for simply supported boundary conditions. The effects of this approximate method were also investigated on the natural frequencies by comparing results with those of the exact analysis.
Keywords: Circular Cylindrical Shell, Free Vibration, Natural Frequency.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3582