Search results for: Phase shifted carrier based pulse width modulation (PSCPWM)
10784 Using Multimedia in Computer Based Learning (CBL) A Case Study: Teaching Science to Student
Authors: Maryam Honarmand
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Regarding to the fast growth of computer, internet, and virtual learning in our country (Iran) and need computer-based learning systems and multimedia tools as an essential part of such education, designing and implementing such systems would help teach different field such as science. This paper describes the basic principle of multimedia. At the end, with a description of learning science to the infant students, the method of this system will be explained.
Keywords: Multimedia tools, computer based learning, science, student.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 149110783 Misleading Node Detection and Response Mechanism in Mobile Ad-Hoc Network
Authors: Earleen Jane Fuentes, Regeene Melarese Lim, Franklin Benjamin Tapia, Alexis Pantola
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Mobile Ad-hoc Network (MANET) is an infrastructure-less network of mobile devices, also known as nodes. These nodes heavily rely on each other’s resources such as memory, computing power, and energy. Thus, some nodes may become selective in forwarding packets so as to conserve their resources. These nodes are called misleading nodes. Several reputation-based techniques (e.g. CORE, CONFIDANT, LARS, SORI, OCEAN) and acknowledgment-based techniques (e.g. TWOACK, S-TWOACK, EAACK) have been proposed to detect such nodes. These techniques do not appropriately punish misleading nodes. Hence, this paper addresses the limitations of these techniques using a system called MINDRA.Keywords: Mobile ad-hoc network, selfish nodes, reputation-based techniques, acknowledgment-based techniques.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 137610782 Concept Abduction in Description Logics with Cardinality Restrictions
Authors: Viet-Hoang Vu, Nhan Le-Thanh
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Recently the usefulness of Concept Abduction, a novel non-monotonic inference service for Description Logics (DLs), has been argued in the context of ontology-based applications such as semantic matchmaking and resource retrieval. Based on tableau calculus, a method has been proposed to realize this reasoning task in ALN, a description logic that supports simple cardinality restrictions as well as other basic constructors. However, in many ontology-based systems, the representation of ontology would require expressive formalisms for capturing domain-specific constraints, this language is not sufficient. In order to increase the applicability of the abductive reasoning method in such contexts, we would like to present in the scope of this paper an extension of the tableaux-based algorithm for dealing with concepts represented inALCQ, the description logic that extends ALN with full concept negation and quantified number restrictions.
Keywords: Abductive reasoning, description logics, semantic matchmaking, non-monotonic inference, tableaux-based method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 155610781 Gas-Solid Nitrocarburizing of Steels: Kinetic Modeling and Experimental Validation
Authors: L. Torchane
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The study is devoted to define the optimal conditions for the nitriding of pure iron at atmospheric pressure by using NH3- Ar-C3H8 gas mixtures. After studying the mechanisms of phase formation and mass transfer at the gas-solid interface, a mathematical model is developed in order to predict the nitrogen transfer rate in the solid, the ε-carbonitride layer growth rate and the nitrogen and carbon concentration profiles. In order to validate the model and to show its possibilities, it is compared with thermogravimetric experiments, analyses and metallurgical observations (X-ray diffraction, optical microscopy and electron microprobe analysis). Results obtained allow us to demonstrate the sound correlation between the experimental results and the theoretical predictions.
Keywords: Gaseous Nitrocarburizing, Kinetic Model, Diffusion, Layer Growth Kinetic.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 218210780 Knowledge Management and e-Learning –An Agent-Based Approach
Authors: Teodora Bakardjieva, Galya Gercheva
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In this paper an open agent-based modular framework for personalized and adaptive curriculum generation in e-learning environment is proposed. Agent-based approaches offer several potential advantages over alternative approaches. Agent-based systems exhibit high levels of flexibility and robustness in dynamic or unpredictable environments by virtue of their intrinsic autonomy. The presented framework enables integration of different types of expert agents, various kinds of learning objects and user modeling techniques. It creates possibilities for adaptive e-learning process. The KM e-learning system is in a process of implementation in Varna Free University and will be used for supporting the educational process at the University.Keywords: agents, e-Learning, knowledge management, knowledge sharing, artificial intelligence
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 216610779 Risk Assessment of Acrylamide Intake from Roasted Potatoes in Latvia
Authors: Irisa Murniece, Daina Karklina, Ruta Galoburda
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From food consumption surveys has been found that potato consumption comparing to other European countries is one of the highest. Hence acrylamide (AA) intake coming from fried potatoes in population might be high as well. The aim of the research was to determine acrylamide content and estimate intake of acrylamide from roasted potatoes bred and cultivated in Latvia. Five common Latvian potato varieties were selected: Lenora, Brasla, Imanta, Zile, and Madara. A two-year research was conducted during two periods: just after harvesting and after six months of storage. Time and temperature (210 ± 5°C) was recorded during frying. AA was extracted from potatoes by solid phase extraction and AA content was determined by LC-MS/MS. estimated intake of acrylamide ranges from 0.012 to 0.496μgkg-1 BW per day.
Keywords: potato, roasting, variety, acrylamide, Latvia, risk assessment.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 206210778 An Analytical Electron Mobility Model based on Particle Swarm Computation for Siliconbased Devices
Authors: F. Djeffal, N. Lakhdar, T. Bendib
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The study of the transport coefficients in electronic devices is currently carried out by analytical and empirical models. This study requires several simplifying assumptions, generally necessary to lead to analytical expressions in order to study the different characteristics of the electronic silicon-based devices. Further progress in the development, design and optimization of Silicon-based devices necessarily requires new theory and modeling tools. In our study, we use the PSO (Particle Swarm Optimization) technique as a computational tool to develop analytical approaches in order to study the transport phenomenon of the electron in crystalline silicon as function of temperature and doping concentration. Good agreement between our results and measured data has been found. The optimized analytical models can also be incorporated into the circuits simulators to study Si-based devices without impact on the computational time and data storage.Keywords: Particle Swarm, electron mobility, Si-based devices, Optimization.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 153810777 Complex Energy Signal Model for Digital Human Fingerprint Matching
Authors: Jason Zalev, Reza Sedaghat
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This paper describes a complex energy signal model that is isomorphic with digital human fingerprint images. By using signal models, the problem of fingerprint matching is transformed into the signal processing problem of finding a correlation between two complex signals that differ by phase-rotation and time-scaling. A technique for minutiae matching that is independent of image translation, rotation and linear-scaling, and is resistant to missing minutiae is proposed. The method was tested using random data points. The results show that for matching prints the scaling and rotation angles are closely estimated and a stronger match will have a higher correlation.Keywords: Affine Invariant, Fingerprint Recognition, Matching, Minutiae.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 131810776 Artificial Neural Network Modeling of a Closed Loop Pulsating Heat Pipe
Authors: Vipul M. Patel, Hemantkumar B. Mehta
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Technological innovations in electronic world demand novel, compact, simple in design, less costly and effective heat transfer devices. Closed Loop Pulsating Heat Pipe (CLPHP) is a passive phase change heat transfer device and has potential to transfer heat quickly and efficiently from source to sink. Thermal performance of a CLPHP is governed by various parameters such as number of U-turns, orientations, input heat, working fluids and filling ratio. The present paper is an attempt to predict the thermal performance of a CLPHP using Artificial Neural Network (ANN). Filling ratio and heat input are considered as input parameters while thermal resistance is set as target parameter. Types of neural networks considered in the present paper are radial basis, generalized regression, linear layer, cascade forward back propagation, feed forward back propagation; feed forward distributed time delay, layer recurrent and Elman back propagation. Linear, logistic sigmoid, tangent sigmoid and Radial Basis Gaussian Function are used as transfer functions. Prediction accuracy is measured based on the experimental data reported by the researchers in open literature as a function of Mean Absolute Relative Deviation (MARD). The prediction of a generalized regression ANN model with spread constant of 4.8 is found in agreement with the experimental data for MARD in the range of ±1.81%.
Keywords: ANN models, CLPHP, filling ratio, generalized regression, spread constant.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 118410775 An Interactive Web-based Simulation Tool for Surgical Thread
Authors: A. Ruimi, S. Goyal, B. M. Nour
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Interactive web-based computer simulations are needed by the medical community to replicate the experience of surgical procedures as closely and realistically as possible without the need to practice on corpses, animals and/or plastic models. In this paper, we offer a review on current state of the research on simulations of surgical threads, identify future needs and present our proposed plans to meet them. Our goal is to create a physics-based simulator, which will predict the behavior of surgical thread when subjected to conditions commonly encountered during surgery. To that end, we will i) develop three dimensional finite element models based on the Cosserat theory of elasticity ii) test and feedback results with the medical community and iii) develop a web-based user interface to run/command our simulator and visualize the results. The impacts of our research are that i) it will contribute to the development of a new generation of training for medical school students and ii) the simulator will be useful to expert surgeons in developing new, better and less risky procedures.Keywords: Cosserat rod-theory, FEM simulations, Modeling, Surgical thread.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 165410774 Performance Analysis of the Time-Based and Periodogram-Based Energy Detector for Spectrum Sensing
Authors: Sadaf Nawaz, Adnan Ahmed Khan, Asad Mahmood, Chaudhary Farrukh Javed
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Classically, an energy detector is implemented in time domain (TD). However, frequency domain (FD) based energy detector has demonstrated an improved performance. This paper presents a comparison between the two approaches as to analyze their pros and cons. A detailed performance analysis of the classical TD energy-detector and the periodogram based detector is performed. Exact and approximate mathematical expressions for probability of false alarm (Pf) and probability of detection (Pd) are derived for both approaches. The derived expressions naturally lead to an analytical as well as intuitive reasoning for the improved performance of (Pf) and (Pd) in different scenarios. Our analysis suggests the dependence improvement on buffer sizes. Pf is improved in FD, whereas Pd is enhanced in TD based energy detectors. Finally, Monte Carlo simulations results demonstrate the analysis reached by the derived expressions.
Keywords: Cognitive radio, energy detector, periodogram, spectrum sensing.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 103010773 Non Destructive Characterisation of Cement Mortar during Carbonation
Authors: Son Tung Pham, William Prince
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The objective of this work was to examine the changes in non destructive properties caused by carbonation of CEM II mortar. Samples of CEM II mortar were prepared and subjected to accelerated carbonation at 20°C, 65% relative humidity and 20% CO2 concentration. We examined the evolutions of the gas permeability, the thermal conductivity, the thermal diffusivity, the volume of the solid phase by helium pycnometry, the longitudinal and transverse ultrasonic velocities. The principal contribution of this work is that, apart of the gas permeability, changes in other non destructive properties have never been studied during the carbonation of cement materials. These properties are important in predicting/measuring the durability of reinforced concrete in CO2 environment. The carbonation depth and the porosity accessible to water were also reported in order to explain comprehensively the changes in non destructive parameters.Keywords: Carbonation, cement mortar, longitudinal and transverse ultrasonic velocities, non destructive tests.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 175110772 The Overload Behaviour of Reinforced Concrete Flexural Members
Authors: Angelo Thurairajah
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Sufficient ultimate deformation is necessary to demonstrate the member ductility, which is dependent on the section and the material ductility. The concrete cracking phase of softening prior to the plastic hinge formation is an essential feature as well. The nature of the overload behaviour is studied using the order of the ultimate deflection. The ultimate deflection is primarily dependent on the slenderness (span to depth ratio), the ductility of the reinforcing steel, the degree of moment redistribution, the type of loading, and the support conditions. The ultimate deflection and the degree of moment redistribution from the analytical study are in good agreement with the experimental results and the moment redistribution provisions of the Australian Standards AS3600 Concrete Structures Code.
Keywords: Ductility, softening, ultimate deflection, overload behaviour, moment redistribution.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 39610771 Finite Element Method Analysis of Occluded-Ear Simulator and Natural Human Ear Canal
Authors: M. Sasajima, T. Yamaguchi, Y. Hu, Y. Koike
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In this paper, we discuss the propagation of sound in the narrow pathways of an occluded-ear simulator typically used for the measurement of insert-type earphones. The simulator has a standardized frequency response conforming to the international standard (IEC60318-4). In narrow pathways, the speed and phase of sound waves are modified by viscous air damping. In our previous paper, we proposed a new finite element method (FEM) to consider the effects of air viscosity in this type of audio equipment. In this study, we will compare the results from the ear simulator FEM model, and those from a three dimensional human ear canal FEM model made from computed tomography images, with the measured frequency response data from the ear canals of 18 people.
Keywords: Ear simulator, FEM, viscosity, human ear canal.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 112810770 The Performance of the Character-Access on the Checking Phase in String Searching Algorithms
Authors: Mahmoud M. Mhashi
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A new algorithm called Character-Comparison to Character-Access (CCCA) is developed to test the effect of both: 1) converting character-comparison and number-comparison into character-access and 2) the starting point of checking on the performance of the checking operation in string searching. An experiment is performed; the results are compared with five algorithms, namely, Naive, BM, Inf_Suf_Pref, Raita, and Circle. With the CCCA algorithm, the results suggest that the evaluation criteria of the average number of comparisons are improved up to 74.0%. Furthermore, the results suggest that the clock time required by the other algorithms is improved in range from 28% to 68% by the new CCCA algorithmKeywords: Pattern matching, string searching, charactercomparison, character-access, and checking.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 130810769 A Robust Controller for Output Variance Reduction and Minimum Variance with Application on a Permanent Field DC-Motor
Authors: Mahmood M. Al-Imam, M. Mustafa
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In this paper, we present an experimental testing for a new algorithm that determines an optimal controller-s coefficients for output variance reduction related to Linear Time Invariant (LTI) Systems. The algorithm features simplicity in calculation, generalization to minimal and non-minimal phase systems, and could be configured to achieve reference tracking as well as variance reduction after compromising with the output variance. An experiment of DCmotor velocity control demonstrates the application of this new algorithm in designing the controller. The results show that the controller achieves minimum variance and reference tracking for a preset velocity reference relying on an identified model of the motor.Keywords: Output variance, minimum variance, overparameterization, DC-Motor.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 135910768 Towards Sustainable Urban Planning In Times of Climate Change
Authors: Rosalba D'onofrio
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It is not easy to imagine how the existing city can be converted to the principles of sustainability, however, the need for innovation, requires a pioneering phase which must address the main problems of rehabilitation of the operating models of the city. Today, however, there is a growing awareness that the identification and implementation of policies and measures to promote the adaptation, resilience and reversibility of the city, require the contribution of our discipline. This breakthrough is present in some recent international experiences of Climate Plans, in which the envisaged measures are closely interwoven with those of urban planning. These experiences, provide some answers principle questions, such as: how the strategies to combat climate can be integrated in the instruments of the local government; what new and specific analysis must be introduced in urban planning in order to understand the issues of urban sustainability, and how the project compares with different spatial scales.Keywords: Climate change, urban sustainability, urban planning
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 155810767 Effect of Aging Condition on Semisolid Cast 2024 Aluminum Alloy
Authors: Wisutmethangoon S., Pannaray S., Plookphol T., Wannasin J.
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2024 Aluminum alloy was squeezed cast by the Gas Induced Semi Solid (GISS) process. Effect of artificial aging on microstructure and mechanical properties of this alloy was studied in the present work. The solutionized specimens were aged hardened at temperatures of 175°C, 200°C, and 225°C under various time durations. The highest hardness of about 77.7 HRE was attained from specimen aged at the temperature of 175°C for 36h. Upon investigation the microstructure by using transmission electron microscopy (TEM), the S’ phase was mainly attributed to the strengthening effect in the aged alloy. The apparent activation energy for precipitation hardening of the alloy was calculated as 133,805 J/mol.
Keywords: 2024 aluminum alloy, Gas induced semi solid, T6 heat treatment, Aged hardening, Transmission electron microscopy.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 301310766 Decision Support System Based on Data Warehouse
Authors: Yang Bao, LuJing Zhang
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Typical Intelligent Decision Support System is 4-based, its design composes of Data Warehouse, Online Analytical Processing, Data Mining and Decision Supporting based on models, which is called Decision Support System Based on Data Warehouse (DSSBDW). This way takes ETL,OLAP and DM as its implementing means, and integrates traditional model-driving DSS and data-driving DSS into a whole. For this kind of problem, this paper analyzes the DSSBDW architecture and DW model, and discusses the following key issues: ETL designing and Realization; metadata managing technology using XML; SQL implementing, optimizing performance, data mapping in OLAP; lastly, it illustrates the designing principle and method of DW in DSSBDW.
Keywords: Decision Support System, Data Warehouse, Data Mining.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 386210765 Design of Collaborative Web System: Based on Case Study of PBL Support Systems
Authors: Kawai Nobuaki
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This paper describes the design and implementation of web system for continuable and viable collaboration. This study proposes the improvement of the system based on a result of a certain practice. As contemporary higher education information environments transform, this study highlights the significance of university identity and college identity that are formed continuously through independent activities of the students. Based on these discussions, the present study proposes a practical media environment design which facilitates the processes of organizational identity formation based on a continuous and cyclical model. Even if users change by this system, the communication system continues operation and cooperation. The activity becomes the archive and produces new activity. Based on the result, this study elaborates a plan with a re-design by a system from the viewpoint of second-order cybernetics. Systems theory is a theoretical foundation for our study.Keywords: Collaborative work, learning management system, second-order cybernetics, systems theory, user generated contents, viable system model.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 90410764 A Weighted Least Square Algorithm for Low-Delay FIR Filters with Piecewise Variable Stopbands
Authors: Yasunori Sugita, Toshinori Yoshikawa, Naoyuki Aikawa
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Variable digital filters are useful for various signal processing and communication applications where the frequency characteristics, such as fractional delays and cutoff frequencies, can be varied. In this paper, we propose a design method of variable FIR digital filters with an approximate linear phase characteristic in the passband. The proposed variable FIR filters have some large attenuation in stopband and their large attenuation can be varied by spectrum parameters. In the proposed design method, a quasi-equiripple characteristic can be obtained by using an iterative weighted least square method. The usefulness of the proposed design method is verified through some examples.
Keywords: Weighted Least Squares Approximation, Variable FIR Filters, Low-Delay, Quasi-Equiripple
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 165810763 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 267210762 Computational Fluid Dynamics Modeling of Downward Bubbly Flows
Authors: Mahmood Reza Rahimi, Hajir Karimi
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Downward turbulent bubbly flows in pipes were modeled using computational fluid dynamics tools. The Hydrodynamics, phase distribution and turbulent structure of twophase air-water flow in a 57.15 mm diameter and 3.06 m length vertical pipe was modeled by using the 3-D Eulerian-Eulerian multiphase flow approach. Void fraction, liquid velocity and turbulent fluctuations profiles were calculated and compared against experimental data. CFD results are in good agreement with experimental data.Keywords: CFD, Bubbly flow, Vertical pipe, Population balance modeling, Gas void fraction, Liquid velocity, Normal turbulent stresses.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 248510761 An Ontology Based Question Answering System on Software Test Document Domain
Authors: Meltem Serhatli, Ferda N. Alpaslan
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Processing the data by computers and performing reasoning tasks is an important aim in Computer Science. Semantic Web is one step towards it. The use of ontologies to enhance the information by semantically is the current trend. Huge amount of domain specific, unstructured on-line data needs to be expressed in machine understandable and semantically searchable format. Currently users are often forced to search manually in the results returned by the keyword-based search services. They also want to use their native languages to express what they search. In this paper, an ontology-based automated question answering system on software test documents domain is presented. The system allows users to enter a question about the domain by means of natural language and returns exact answer of the questions. Conversion of the natural language question into the ontology based query is the challenging part of the system. To be able to achieve this, a new algorithm regarding free text to ontology based search engine query conversion is proposed. The algorithm is based on investigation of suitable question type and parsing the words of the question sentence.Keywords: Description Logics, ontology, question answering, reasoning.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 214910760 Functionality of Negotiation Agent on Value-based Design Decision
Authors: Arazi Idrus, Christiono Utomo
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This paper presents functionality of negotiation agent on value-based design decision. The functionality is based on the characteristics of the system and goal specification. A Prometheus Design Tool model was used for developing the system. Group functionality will be the attribute for negotiation agents, which comprises a coordinator agent and decision- maker agent. The results of the testing of the system to a building system selection on valuebased decision environment are also presented.Keywords: Functionality, negotiation agent, value-baseddecision
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 142010759 Lime-Pozzolan Plasters with Enhanced Thermal Capacity
Authors: Z. Pavlík, A. Trník, M. Pavlíková, M. Keppert, R. Černý
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A new type of lightweight plaster with the thermal capacity enhanced by PCM (Phase Change Material) addition is analyzed. The basic physical characteristics, namely the bulk density, matrix density, total open porosity, and pore size distribution are measured at first. For description of mechanical properties, compressive strength measurements are done. The thermal properties are characterized by transient impulse techniques as well as by DSC analysis that enables determination of the specific heat capacity as a function of temperature. The resistivity against the liquid water ingress is described by water absorption coefficient measurement. The experimental results indicate a good capability of the designed plaster to moderate effectively the interior climate of buildings.
Keywords: Lime-pozzolan plaster, PCM addition, enhanced thermal capacity, DSC analysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 243710758 Batteryless DCM Boost Converter for Kinetic Energy Harvesting Applications
Authors: Andrés Gomez-Casseres, Rubén Contreras
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In this paper, a bidirectional boost converter operated in Discontinuous Conduction Mode (DCM) is presented as a suitable power conditioning circuit for tuning of kinetic energy harvesters without the need of a battery. A nonlinear control scheme, composed by two linear controllers, is used to control the average value of the input current, enabling the synthesization of complex loads. The converter, along with the control system, is validated through SPICE simulations using the LTspice tool. The converter model and the controller transfer functions are derived. From the simulation results, it was found that the input current distortion increases with the introduced phase shift and that, such distortion, is almost entirely present at the zero-crossing point of the input voltage.Keywords: Average current control, boost converter, electrical tuning, energy harvesting.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 110810757 Micro Environmental Concrete
Authors: M.Lanez, M.N.Oudjit, A.Bali
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Reactive powder concretes (RPC) are characterized by particle diameter not exceeding 600 μm and having very high compressive and tensile strengths. This paper describes a new generation of micro concrete, which has an initial, as well as a final, high physicomechanical performance. To achieve this, we replaced the Portland cement (15% by weight) by materials rich in Silica (Slag and Dune Sand). The results obtained from tests carried out on RPC show that compressive and tensile strengths increase when adding the additions, thus improving the compactness of mixtures via filler and pozzolanic effect. With a reduction of the aggregate phase in the RPC and the abundance of dune sand (south Algeria) and slag (industrial byproduct of blast furnace), the use of the RPC will allow Algeria to fulfil economical as well as ecological requirements.Keywords: High mechanical strength, Reactive Powder Concrete, rheology, superplasticizer, workability
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 152510756 Relationships among Tourists’ Needs for Uniqueness, Perceived Authenticity and Behavioral Intentions
Authors: Deniz Karagöz Yüncü
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This study tested a structural model which investigates the relationships among tourists’ need for uniqueness, perceived authenticity (object-based authenticity and existential authenticity) and behavioral intentions to consume cultural and heritage destinations. The sample of the study comprised of 281 participants in a cultural heritage site, in Cappadocia, Turkey. The data were provided via face to face interviews in two months (September and October) which considered the high season. Structural equation modeling was employed to test the causal relationships among the hypotheses. Findings revealed tourists’ creative choice had an influence on object-based authenticity and existential authenticity. Tourists’ avoidance had an influence on object-based authenticity. The study concluded that two dimensions, namely, the object based authenticity and existential authenticity had significant impact on behavioral intentions.
Keywords: Needs for uniqueness, object-based authenticity, existential authenticity, behavioral intentions.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 165110755 The Establishment of Probabilistic Risk Assessment Analysis Methodology for Dry Storage Concrete Casks Using SAPHIRE 8
Authors: J. R. Wang, W. Y. Cheng, J. S. Yeh, S. W. Chen, Y. M. Ferng, J. H. Yang, W. S. Hsu, C. Shih
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To understand the risk for dry storage concrete casks in the cask loading, transfer, and storage phase, the purpose of this research is to establish the probabilistic risk assessment (PRA) analysis methodology for dry storage concrete casks by using SAPHIRE 8 code. This analysis methodology is used to perform the study of Taiwan nuclear power plants (NPPs) dry storage system. The process of research has three steps. First, the data of the concrete casks and Taiwan NPPs are collected. Second, the PRA analysis methodology is developed by using SAPHIRE 8. Third, the PRA analysis is performed by using this methodology. According to the analysis results, the maximum risk is the multipurpose canister (MPC) drop case.
Keywords: PRA, Dry storage, concrete cask, SAPHIRE.
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