Search results for: generating Sudoku puzzles
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1013

Search results for: generating Sudoku puzzles

803 Application of Matrix Converter for the Power Control of a DFIG-Based Wind Turbine

Authors: E. Bounadja, M. O. Mahmoudi, A. Djahbar, Z. Boudjema

Abstract:

This paper presents a control approach of the doubly fed induction generator (DFIG) in conjunction with a direct AC-AC matrix converter used in generating mode. This device is intended to be implemented in a variable speed wind energy conversion system connected to the grid. Firstly, we developed a model of matrix converter, controlled by the Venturini modulation technique. In order to control the power exchanged between the stator of the DFIG and the grid, a control law is synthesized using a high order sliding mode controller. The use of this method provides very satisfactory performance for the DFIG control. The overall strategy has been validated on a 2-MW wind turbine driven a DFIG using the Matlab/Simulink.

Keywords: doubly fed induction generator (DFIG), matrix converter, high-order sliding mode controller, wind energy

Procedia PDF Downloads 496
802 The Implications of Person-Organisation Spirituality Fit on Employees’ Ethical and Spiritual Leadership Behaviours: Insights from Jordan

Authors: Tamer Koburtay, Radi Haloub

Abstract:

Person-Organization fit theory concerns how people flourish in a workplace that is congruence with their values and other traits. This paper seeks to highlight the theoretical relevance that workplace spirituality may add to the existing theory development of the P-O fit. In specific, it aims to empirically test the emerged framework that encompasses how workplace and self-spirituality match may enhance the perceived P-O fit, and how such a fit can enhance both employees’ ethical behaviors (i.e., humanism and honesty) and spiritual leadership behaviors. Drawing on a survey of the private and public sectors in Jordan, the results reveal that increasing the match in workplace and employees’ spirituality positively enhances the perceived P-O fit. Further, ethical and spiritual behaviors were found to be positively linked with a higher P-O fit. The importance of this paper is by generating a concept (i.e., P-O spirituality fit) beyond the already vast literature on P-O fit.

Keywords: ethical behavior, leadership, P-O fit, spirituality, leadership

Procedia PDF Downloads 120
801 Application of Statistical Linearized Models for Investigations of Digital Dynamic Pulse-Frequency Control Systems

Authors: B. H. Aitchanov, Sh. K. Aitchanova, O. A. Baimuratov

Abstract:

This paper is focused on dynamic pulse-frequency modulation (DPFM) control systems. Currently, the control law based on DPFM control signals is widely used in direct digital control subsystems introduced in the automated control systems of technological processes. Statistical analysis of automatic control systems is reduced to its construction of functional relationships between the statistical characteristics of the errors processes and input processes. Structural and dynamic Volterra models of digital pulse-frequency control systems can be used to develop methods for generating the dependencies, differing accuracy, requiring the amount of information about the statistical characteristics of input processes and computing labor intensity of their use.

Keywords: digital dynamic pulse-frequency control systems, dynamic pulse-frequency modulation, control object, discrete filter, impulse device, microcontroller

Procedia PDF Downloads 462
800 On a Single Server Queue with Arrivals in Batches of Variable Size, Generalized Coxian-2 Service and Compulsory Server Vacations

Authors: Kailash C. Madan

Abstract:

We study the steady state behaviour of a batch arrival single server queue in which the first service with general service times is compulsory and the second service with general service times is optional. We term such a two phase service as generalized Coxian-2 service. Just after completion of a service the server must take a vacation of random length of time with general vacation times. We obtain steady state probability generating functions for the queue size as well as the steady state mean queue size at a random epoch of time in explicit and closed forms. Some particular cases of interest including some known results have been derived.

Keywords: batch arrivals, compound Poisson process, generalized Coxian-2 service, steady state

Procedia PDF Downloads 427
799 Hierarchical Surface Inspired by Lotus-Leaf for Electrical Generators from Waterdrop

Authors: Jaewook Ha, Jin-beak Kim, Seongmin Kim

Abstract:

In order to solve global warming and climate change issues, increased efforts have been devoted towards clean and sustainable energy sources as well as new energy generating devices. Nanogenerator is a device that converts mechanical/thermal energy as produced by small-scale physical change into electricity. Here we propose that nature-leaf surface could be used for preparation of a triboelectric nanogenerator. The nature-leaf surface consists of polydimethylsiloxane microscale pillars and polytetrafluoroethylene nanoparticles. Interaction between the nature-leaf surface and water was studied and the electrical outputs from the motion of single water drop were measured. A 40-μL water drop can generate a peak voltage of 1 V and a peak current of 0.7 μA. This nanogenerator might be used to drive electric devices in the outdoor environments in a sustainable manner.

Keywords: hierarchical surface, lotus-leaf, electrical generator, waterdrop

Procedia PDF Downloads 255
798 Polymer in Electronic Waste: An Analysis

Authors: Anis A. Ansari, Aftab A. Ansari

Abstract:

Electronic waste is inundating the traditional solid-waste-disposal facilities, which are inadequately designed to handle and manage such type of new wastes. Since electronic waste contains mostly hazardous and even toxic materials, the seriousness of its effects on human health and the environment cannot be ignored in present scenario. Waste from the electronic industry is increasing exponentially day by day. From the last 20 years, we are continuously generating huge quantities of e-waste such as obsolete computers and other discarded electronic components, mainly due to evolution of newer technologies as a result of constant efforts in research and development in this sector. Polymers, one of the major constituents in almost every electronic waste, such as computers, printers, electronic equipment, entertainment devices, mobile phones, television sets etc., are if properly recycled can create a new business opportunity. This would not only create potential market for polymers to improve economy but also the priceless land used as dumping sites of electronic waste, can be utilized for other productive purposes.

Keywords: polymer recycling, electronic waste, hazardous materials, electronic components

Procedia PDF Downloads 442
797 The Role of the Returned Migration in the Regional Economic Growth

Authors: Jessica Ordoñez, Francisco Ochoa, Pascual García

Abstract:

The objective of this paper is to analyze the relationship between return migration in Ecuador and economic growth. The improvement of macroeconomic conditions in Latin America, starting in 2012, makes the region a new migratory destination, in both senses in north-south and south-south flows. Current studies highlight only the role of the entrepreneurial migrant in generating employment and economic growth in the region. Nevertheless, it has not been considered that not all migrants are entrepreneurs and that not all entrepreneurs contribute to economic growth. This research compares the socioeconomic and labor characteristics of migrant returnees working as freelancers in Ecuador. The principal aim is to demystify the role of migrant entrepreneurs in regional growth and to identify socioeconomic characteristics that can enhance growth. A panel econometric model was used, which is part of the information from labor and macroeconomic surveys.

Keywords: economic growth, entrepreneur, migration, returned migration

Procedia PDF Downloads 180
796 An Improved Genetic Algorithm for Traveling Salesman Problem with Precedence Constraint

Authors: M. F. F. Ab Rashid, A. N. Mohd Rose, N. M. Z. Nik Mohamed, W. S. Wan Harun, S. A. Che Ghani

Abstract:

Traveling salesman problem with precedence constraint (TSPPC) is one of the most complex problems in combinatorial optimization. The existing algorithms to solve TSPPC cost large computational time to find the optimal solution. The purpose of this paper is to present an efficient genetic algorithm that guarantees optimal solution with less number of generations and iterations time. Unlike the existing algorithm that generates priority factor as chromosome, the proposed algorithm directly generates sequence of solution as chromosome. As a result, the proposed algorithm is capable of generating optimal solution with smaller number of generations and iteration time compare to existing algorithm.

Keywords: traveling salesman problem, sequencing, genetic algorithm, precedence constraint

Procedia PDF Downloads 534
795 Development of Scale in Evaluation of Effectiveness of Motivation of Divine Leadership

Authors: Parviz Abadi

Abstract:

Leadership is a key driver in organizational achievement. The research presented herein intends on providing the tools for assessing Divine Leadership, which imperative in quantitative evaluations of a leadership. The effectiveness of this leadership has never been examined. There are various tests that can be applied to this leadership, such as evaluation of it against follower motivation, or the impact it has on organizational success, etc. One of the common means of evaluation of a phenomenon is to conduct a quantitative study on the hypothesis related to the subject. The dimensions enacted in this leadership consisted of Humility, Integrity, Empowerment, Altruism, and Visionary. However, these elements of the construct of leadership are latent subjects and cannot easily be assessed. Therefore, it is necessary to develop tangible items that can relate to the construct. The study presented herein was conducted to develop the scales that were tangible and could have been applied in a quantitative study to assess this leadership. The study led to generating a detailed questionnaire, which consisted of 40 questions, that could be presented to participants in the survey.

Keywords: leadership, management, scale development, organizations

Procedia PDF Downloads 24
794 Perceptions on Development of the Deaf in Higher Education Level: The Case of Special Education Students in Tiaong, Quezon, Philippines

Authors: Ashley Venerable, Rosario Tatlonghari

Abstract:

This study identified how college deaf students of Bartimaeus Center for Alternative Learning in Tiaong, Quezon, Philippines view development using visual communication techniques and generating themes from responses. Complete enumeration was employed. Guided by Constructivist Theory of Perception, past experiences and stored information influenced perception. These themes of development emerged: social development; pleasant environment; interpersonal relationships; availability of resources; employment; infrastructure development; values; and peace and security. Using the National Economic and Development Authority development indicators, findings showed the deaf students’ views on development were similar from the mainstream views. Responses also became more meaningful through visual communication techniques.

Keywords: deaf, development, perception, development indicators, visual communication

Procedia PDF Downloads 395
793 Investigation of Graphene-MoS₂ Nanocomposite as Counter Electrode in Dye-Sensitized Solar Cells

Authors: Mozhgan Hosseinnezhad, Kamaladin Gharanjig, Mehdi Ghahari

Abstract:

Dye-sensitized solar cells are sustainable tool for generating electrical energy using sunlight. To develop this technology, obstacles such as cost and the use of expensive compounds must be overcome. Herein, we employed a MoS₂/graphene composite instead of platinum in the DSSCs. Platinum is an efficient and conventional counter electrode in the preparation of DSSCs, for this purpose, the effect of the presence of platinum electrode was also studied under similar conditions. The prepared nanocomposite product was checked by analysis methods to confirm the correctness of the construction and the desired structure. Finally, the DSSCs were fabricated using MoS₂/graphene composite, and to compare the results, the DSSCs were also prepared using platinum. The results showed that the prepared composite has a similar performance compared to platinum and can replace it.

Keywords: efficiency, dye-sensitized solar cell, nano-composite MoS₂, platinum free

Procedia PDF Downloads 35
792 All-or-None Principle and Weakness of Hodgkin-Huxley Mathematical Model

Authors: S. A. Sadegh Zadeh, C. Kambhampati

Abstract:

Mathematical and computational modellings are the necessary tools for reviewing, analysing, and predicting processes and events in the wide spectrum range of scientific fields. Therefore, in a field as rapidly developing as neuroscience, the combination of these two modellings can have a significant role in helping to guide the direction the field takes. The paper combined mathematical and computational modelling to prove a weakness in a very precious model in neuroscience. This paper is intended to analyse all-or-none principle in Hodgkin-Huxley mathematical model. By implementation the computational model of Hodgkin-Huxley model and applying the concept of all-or-none principle, an investigation on this mathematical model has been performed. The results clearly showed that the mathematical model of Hodgkin-Huxley does not observe this fundamental law in neurophysiology to generating action potentials. This study shows that further mathematical studies on the Hodgkin-Huxley model are needed in order to create a model without this weakness.

Keywords: all-or-none, computational modelling, mathematical model, transmembrane voltage, action potential

Procedia PDF Downloads 582
791 Energy Management System Based on Voltage Fluctuations Minimization for Droop-Controlled Islanded Microgrid

Authors: Zahra Majd, Mohsen Kalantar

Abstract:

Power management and voltage regulation is one of the most important issues in microgrid (MG) control and scheduling. This paper proposes a multiobjective scheduling formulation that consists of active power costs, voltage fluctuations summation, and technical constraints of MG. Furthermore, load flow and reserve constraints are considered to achieve proper voltage regulation. A modified Jacobian matrix is presented for calculating voltage variations and Mont Carlo simulation is used for generating and reducing scenarios. To convert the problem to a mixed integer linear program, a linearization procedure for nonlinear equations is presented. The proposed model is applied to a typical low-voltage MG and two different cases are investigated. The results show the effectiveness of the proposed model.

Keywords: microgrid, energy management system, voltage fluctuations, modified Jacobian matrix

Procedia PDF Downloads 57
790 Automated Test Data Generation For some types of Algorithm

Authors: Hitesh Tahbildar

Abstract:

The cost of test data generation for a program is computationally very high. In general case, no algorithm to generate test data for all types of algorithms has been found. The cost of generating test data for different types of algorithm is different. Till date, people are emphasizing the need to generate test data for different types of programming constructs rather than different types of algorithms. The test data generation methods have been implemented to find heuristics for different types of algorithms. Some algorithms that includes divide and conquer, backtracking, greedy approach, dynamic programming to find the minimum cost of test data generation have been tested. Our experimental results say that some of these types of algorithm can be used as a necessary condition for selecting heuristics and programming constructs are sufficient condition for selecting our heuristics. Finally we recommend the different heuristics for test data generation to be selected for different types of algorithms.

Keywords: ongest path, saturation point, lmax, kL, kS

Procedia PDF Downloads 368
789 Artificial Intelligence Based Analysis of Magnetic Resonance Signals for the Diagnosis of Tissue Abnormalities

Authors: Kapila Warnakulasuriya, Walimuni Janaka Mendis

Abstract:

In this study, an artificial intelligence-based approach is developed to diagnose abnormal tissues in human or animal bodies by analyzing magnetic resonance signals. As opposed to the conventional method of generating an image from the magnetic resonance signals, which are then evaluated by a radiologist for the diagnosis of abnormalities, in the discussed approach, the magnetic resonance signals are analyzed by an artificial intelligence algorithm without having to generate or analyze an image. The AI-based program compares magnetic resonance signals with millions of possible magnetic resonance waveforms which can be generated from various types of normal tissues. Waveforms generated by abnormal tissues are then identified, and images of the abnormal tissues are generated with the possible location of them in the body for further diagnostic tests.

Keywords: magnetic resonance, artificial intelligence, magnetic waveform analysis, abnormal tissues

Procedia PDF Downloads 57
788 Improoving Readability for Tweet Contextualization Using Bipartite Graphs

Authors: Amira Dhokar, Lobna Hlaoua, Lotfi Ben Romdhane

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Tweet contextualization (TC) is a new issue that aims to answer questions of the form 'What is this tweet about?' The idea of this task was imagined as an extension of a previous area called multi-document summarization (MDS), which consists in generating a summary from many sources. In both TC and MDS, the summary should ideally contain the most relevant information of the topic that is being discussed in the source texts (for MDS) and related to the query (for TC). Furthermore of being informative, a summary should be coherent, i.e. well written to be readable and grammatically compact. Hence, coherence is an essential characteristic in order to produce comprehensible texts. In this paper, we propose a new approach to improve readability and coherence for tweet contextualization based on bipartite graphs. The main idea of our proposed method is to reorder sentences in a given paragraph by combining most expressive words detection and HITS (Hyperlink-Induced Topic Search) algorithm to make up a coherent context.

Keywords: bipartite graphs, readability, summarization, tweet contextualization

Procedia PDF Downloads 164
787 A Model Architecture Transformation with Approach by Modeling: From UML to Multidimensional Schemas of Data Warehouses

Authors: Ouzayr Rabhi, Ibtissam Arrassen

Abstract:

To provide a complete analysis of the organization and to help decision-making, leaders need to have relevant data; Data Warehouses (DW) are designed to meet such needs. However, designing DW is not trivial and there is no formal method to derive a multidimensional schema from heterogeneous databases. In this article, we present a Model-Driven based approach concerning the design of data warehouses. We describe a multidimensional meta-model and also specify a set of transformations starting from a Unified Modeling Language (UML) metamodel. In this approach, the UML metamodel and the multidimensional one are both considered as a platform-independent model (PIM). The first meta-model is mapped into the second one through transformation rules carried out by the Query View Transformation (QVT) language. This proposal is validated through the application of our approach to generating a multidimensional schema of a Balanced Scorecard (BSC) DW. We are interested in the BSC perspectives, which are highly linked to the vision and the strategies of an organization.

Keywords: data warehouse, meta-model, model-driven architecture, transformation, UML

Procedia PDF Downloads 128
786 A Generalized Framework for Adaptive Machine Learning Deployments in Algorithmic Trading

Authors: Robert Caulk

Abstract:

A generalized framework for adaptive machine learning deployments in algorithmic trading is introduced, tested, and released as open-source code. The presented software aims to test the hypothesis that recent data contains enough information to form a probabilistically favorable short-term price prediction. Further, the framework contains various adaptive machine learning techniques that are geared toward generating profit during strong trends and minimizing losses during trend changes. Results demonstrate that this adaptive machine learning approach is capable of capturing trends and generating profit. The presentation also discusses the importance of defining the parameter space associated with the dynamic training data-set and using the parameter space to identify and remove outliers from prediction data points. Meanwhile, the generalized architecture enables common users to exploit the powerful machinery while focusing on high-level feature engineering and model testing. The presentation also highlights common strengths and weaknesses associated with the presented technique and presents a broad range of well-tested starting points for feature set construction, target setting, and statistical methods for enforcing risk management and maintaining probabilistically favorable entry and exit points. The presentation also describes the end-to-end data processing tools associated with FreqAI, including automatic data fetching, data aggregation, feature engineering, safe and robust data pre-processing, outlier detection, custom machine learning and statistical tools, data post-processing, and adaptive training backtest emulation, and deployment of adaptive training in live environments. Finally, the generalized user interface is also discussed in the presentation. Feature engineering is simplified so that users can seed their feature sets with common indicator libraries (e.g. TA-lib, pandas-ta). The user also feeds data expansion parameters to fill out a large feature set for the model, which can contain as many as 10,000+ features. The presentation describes the various object-oriented programming techniques employed to make FreqAI agnostic to third-party libraries and external data sources. In other words, the back-end is constructed in such a way that users can leverage a broad range of common regression libraries (Catboost, LightGBM, Sklearn, etc) as well as common Neural Network libraries (TensorFlow, PyTorch) without worrying about the logistical complexities associated with data handling and API interactions. The presentation finishes by drawing conclusions about the most important parameters associated with a live deployment of the adaptive learning framework and provides the road map for future development in FreqAI.

Keywords: machine learning, market trend detection, open-source, adaptive learning, parameter space exploration

Procedia PDF Downloads 63
785 The Effect of Low Voltage Direct Current Applications on the Growth of Microalgae Chlorella Vulgaris

Authors: Osman Kök, İlhami̇ Tüzün, Yaşar Aluç

Abstract:

This study was conducted to explore the effect of direct current (DC) applications on the growth of microalgae Chlorella vulgaris KKU71, isolated from highly saline freshwater. Experiments were implemented based upon the cross-combinations of both the intensity and duration of electric applications, generating a full factorial design of 10V, 20V, 30V, and 5s, 30s, 60s, respectively. Growth parameters of cultures were monitored on Optical Density (OD), Cell Count (CC), Chlorophyll-a, b (Chl-a, b), and Total Carotenoids (TCar). All DC-assisted treatments stimulated the growth and thus led to higher values of growth parameters such as OD, CC, Chl-a, and TCar. Monotonically increasing with the intensity and duration of DC applications, wet and dry biomass yields of the harvested algae reached their highest level at 30V-60s in all sets of treatments. In addition, this increase between DC applications was listed as C(control)<10V<20V<30V and C<5s<30s<60s. As a result, direct current applications increased the biomass.

Keywords: Chlorella Vulgaris, direct current, growth, biomass

Procedia PDF Downloads 105
784 Testing Chat-GPT: An AI Application

Authors: Jana Ismail, Layla Fallatah, Maha Alshmaisi

Abstract:

ChatGPT, a cutting-edge language model built on the GPT-3.5 architecture, has garnered attention for its profound natural language processing capabilities, holding promise for transformative applications in customer service and content creation. This study delves into ChatGPT's architecture, aiming to comprehensively understand its strengths and potential limitations. Through systematic experiments across diverse domains, such as general knowledge and creative writing, we evaluated the model's coherence, context retention, and task-specific accuracy. While ChatGPT excels in generating human-like responses and demonstrates adaptability, occasional inaccuracies and sensitivity to input phrasing were observed. The study emphasizes the impact of prompt design on output quality, providing valuable insights for the nuanced deployment of ChatGPT in conversational AI and contributing to the ongoing discourse on the evolving landscape of natural language processing in artificial intelligence.

Keywords: artificial Inelegance, chatGPT, open AI, NLP

Procedia PDF Downloads 34
783 Generating 3D Anisotropic Centroidal Voronoi Tessellations

Authors: Alexandre Marin, Alexandra Bac, Laurent Astart

Abstract:

New numerical methods for PDE resolution (such as Finite Volumes (FV) or Virtual Elements Method (VEM)) open new needs in terms of meshing of domains of interest, and in particular, polyhedral meshes have many advantages. One way to build such meshes consists of constructing Restricted Voronoi Diagrams (RVDs) whose boundaries respect the domain of interest. By minimizing a function defined for RVDs, the shapes of cells can be controlled, e.g., elongated according to user-defined directions or adjusted to comply with given aspect ratios (anisotropy) and density variations. In this paper, our contribution is threefold: First, we introduce a new gradient formula for the Voronoi tessellation energy under a continuous anisotropy field. Second, we describe a meshing algorithm based on the optimisation of this function that we validate against state-of-the-art approaches. Finally, we propose a hierarchical approach to speed up our meshing algorithm.

Keywords: anisotropic Voronoi diagrams, meshes for numerical simulations, optimisation, volumic polyhedral meshing

Procedia PDF Downloads 58
782 The Conduct of Laundering Money through Transport of Cash in the Middle East and North Africa Region

Authors: Haytham Yassine

Abstract:

This article mainly aims to detect and understand how money laundering activities are executed by transport of cash, identifying the underlying factors and separating legitimate from illegitimate usage of cash and how it is being used. This research provides academics with additional literature and provides bank supervisors and practitioners with a better understanding of sources and uses of cash in criminal activities and how cash is used in the laundering mechanism. Data are gathered through survey in the Middle East and North Africa region and review of the available research. The results of the analysis will help distinguish the factors affecting preference for cash rather other payment instruments in the region, identify what causes the tendency to launder illegal proceeds through cash transportation and how illegal cash is being laundered and moved. On the other hand, this paper sheds the light on major cash generating criminal activities, its sources and main destinations.

Keywords: illegitimate activities, cash, money laundering, terrorism financing

Procedia PDF Downloads 116
781 Batman Forever: The Economics of Overlapping Rights

Authors: Franziska Kaiser, Alexander Cuntz

Abstract:

When copyrighted comic characters are also protected under trademark laws, intellectual property (IP) rights can overlap. Arguably, registering a trademark can increase transaction costs for cross-media uses of characters, or it can favor advertise across a number of sales channels. In an application to book, movie, and video game publishing industries, we thus ask how creative reuse is affected in situations of overlapping rights and whether ‘fuzzy boundaries’ of right frameworks are, in fact, enhancing or decreasing content sales. We use a major U.S. Supreme Court decision as a quasi-natural experiment to apply an IV estimation in our analysis. We find that overlapping rights frameworks negatively affect creative reuses. At large, when copyright-protected comic characters are additionally registered as U.S. trademarks, they are less often reprinted and enter fewer video game productions while generating less revenue from game sales.

Keywords: copyright, fictional characters, trademark, reuse

Procedia PDF Downloads 184
780 A Formal Approach for Instructional Design Integrated with Data Visualization for Learning Analytics

Authors: Douglas A. Menezes, Isabel D. Nunes, Ulrich Schiel

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Most Virtual Learning Environments do not provide support mechanisms for the integrated planning, construction and follow-up of Instructional Design supported by Learning Analytic results. The present work aims to present an authoring tool that will be responsible for constructing the structure of an Instructional Design (ID), without the data being altered during the execution of the course. The visual interface aims to present the critical situations present in this ID, serving as a support tool for the course follow-up and possible improvements, which can be made during its execution or in the planning of a new edition of this course. The model for the ID is based on High-Level Petri Nets and the visualization forms are determined by the specific kind of the data generated by an e-course, a population of students generating sequentially dependent data.

Keywords: educational data visualization, high-level petri nets, instructional design, learning analytics

Procedia PDF Downloads 218
779 Geometric Optimisation of Piezoelectric Fan Arrays for Low Energy Cooling

Authors: Alastair Hales, Xi Jiang

Abstract:

Numerical methods are used to evaluate the operation of confined face-to-face piezoelectric fan arrays as pitch, P, between the blades is varied. Both in-phase and counter-phase oscillation are considered. A piezoelectric fan consists of a fan blade, which is clamped at one end, and an extremely low powered actuator. This drives the blade tip’s oscillation at its first natural frequency. Sufficient blade tip speed, created by the high oscillation frequency and amplitude, is required to induce vortices and downstream volume flow in the surrounding air. A single piezoelectric fan may provide the ideal solution for low powered hot spot cooling in an electronic device, but is unable to induce sufficient downstream airflow to replace a conventional air mover, such as a convection fan, in power electronics. Piezoelectric fan arrays, which are assemblies including multiple fan blades usually in face-to-face orientation, must be developed to widen the field of feasible applications for the technology. The potential energy saving is significant, with a 50% power demand reduction compared to convection fans even in an unoptimised state. A numerical model of a typical piezoelectric fan blade is derived and validated against experimental data. Numerical error is found to be 5.4% and 9.8% using two data comparison methods. The model is used to explore the variation of pitch as a function of amplitude, A, for a confined two-blade piezoelectric fan array in face-to-face orientation, with the blades oscillating both in-phase and counter-phase. It has been reported that in-phase oscillation is optimal for generating maximum downstream velocity and flow rate in unconfined conditions, due at least in part to the beneficial coupling between the adjacent blades that leads to an increased oscillation amplitude. The present model demonstrates that confinement has a significant detrimental effect on in-phase oscillation. Even at low pitch, counter-phase oscillation produces enhanced downstream air velocities and flow rates. Downstream air velocity from counter-phase oscillation can be maximally enhanced, relative to that generated from a single blade, by 17.7% at P = 8A. Flow rate enhancement at the same pitch is found to be 18.6%. By comparison, in-phase oscillation at the same pitch outputs 23.9% and 24.8% reductions in peak downstream air velocity and flow rate, relative to that generated from a single blade. This optimal pitch, equivalent to those reported in the literature, suggests that counter-phase oscillation is less affected by confinement. The optimal pitch for generating bulk airflow from counter-phase oscillation is large, P > 16A, due to the small but significant downstream velocity across the span between adjacent blades. However, by considering design in a confined space, counterphase pitch should be minimised to maximise the bulk airflow generated from a certain cross-sectional area within a channel flow application. Quantitative values are found to deviate to a small degree as other geometric and operational parameters are varied, but the established relationships are maintained.

Keywords: piezoelectric fans, low energy cooling, power electronics, computational fluid dynamics

Procedia PDF Downloads 194
778 Sustainability Assessment of Municipal Wastewater Treatment

Authors: Yousra Zakaria Ahmed, Ahmed El Gendy, Salah El Haggar

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In this paper, our methodology to assess sustainability of wastewater treatment technologies in Egypt is presented. The preliminary list of factors to be considered, as well as their ranking listed. The factors include, but are not limited to pollutants removal efficiency and energy consumption under the environmental dimension, construction cost, operation and maintenance costs and required land area cost under the economic dimension and public acceptance, noise and generating job opportunities for local residents. This methodology is intended to be a user-friendly screening tool to support the decision making process when investigating different wastewater treatment technologies in Egypt. Based on the research work results presented in this paper, it can be generally concluded that the categorization of some of the social and environmental aspects of sustainability is subjective and highly dependent on the local conditions and researchers’ background.

Keywords: sustainability, wastewater treatment, sustainability assessment, Egypt

Procedia PDF Downloads 465
777 Learning the History of a Tuscan Village: A Serious Game Using Geolocation Augmented Reality

Authors: Irene Capecchi, Tommaso Borghini, Iacopo Bernetti

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An important tool for the enhancement of cultural sites is serious games (SG), i.e., games designed for educational purposes; SG is applied in cultural sites through trivia, puzzles, and mini-games for participation in interactive exhibitions, mobile applications, and simulations of past events. The combination of Augmented Reality (AR) and digital cultural content has also produced examples of cultural heritage recovery and revitalization around the world. Through AR, the user perceives the information of the visited place in a more real and interactive way. Another interesting technological development for the revitalization of cultural sites is the combination of AR and Global Positioning System (GPS), which integrated have the ability to enhance the user's perception of reality by providing historical and architectural information linked to specific locations organized on a route. To the author’s best knowledge, there are currently no applications that combine GPS AR and SG for cultural heritage revitalization. The present research focused on the development of an SG based on GPS and AR. The study area is the village of Caldana in Tuscany, Italy. Caldana is a fortified Renaissance village; the most important architectures are the walls, the church of San Biagio, the rectory, and the marquis' palace. The historical information is derived from extensive research by the Department of Architecture at the University of Florence. The storyboard of the SG is based on the history of the three characters who built the village: marquis Marcello Agostini, who was commissioned by Cosimo I de Medici, Grand Duke of Tuscany, to build the village, his son Ippolito and his architect Lorenzo Pomarelli. The three historical characters were modeled in 3D using the freeware MakeHuman and imported into Blender and Mixamo to associate a skeleton and blend shapes to have gestural animations and reproduce lip movement during speech. The Unity Rhubarb Lip Syncer plugin was used for the lip sync animation. The historical costumes were created by Marvelous Designer. The application was developed using the Unity 3D graphics and game engine. The AR+GPS Location plugin was used to position the 3D historical characters based on GPS coordinates. The ARFoundation library was used to display AR content. The SG is available in two versions: for children and adults. the children's version consists of finding a digital treasure consisting of valuable items and historical rarities. Players must find 9 village locations where 3D AR models of historical figures explaining the history of the village provide clues. To stimulate players, there are 3 levels of rewards for every 3 clues discovered. The rewards consist of AR masks for archaeologist, professor, and explorer. At the adult level, the SG consists of finding the 16 historical landmarks in the village, and learning historical and architectural information interactively and engagingly. The application is being tested on a sample of adults and children. Test subjects will be surveyed on a Likert scale to find out their perceptions of using the app and the learning experience between the guided tour and interaction with the app.

Keywords: augmented reality, cultural heritage, GPS, serious game

Procedia PDF Downloads 62
776 Parameters Influencing the Output Precision of a Lens-Lens Beam Generator Solar Concentrator

Authors: M. Tawfik, X. Tonnellier, C. Sansom

Abstract:

The Lens-Lens Beam Generator (LLBG) is a Fresnel-based optical concentrating technique which provides flexibility in selecting the solar receiver location compared to conventional techniques through generating a powerful concentrated collimated solar beam. In order to achieve that, two successive lenses are used and followed by a flat mirror. Hence the generated beam emerging from the LLBG has a high power flux which impinges on the target receiver, it is important to determine the precision of the system output. In this present work, mathematical investigation of different parameters affecting the precision of the output beam is carried out. These parameters include: Deflection in sun-facing lens and its holding arm, delay in updating the solar tracking system, and the flat mirror surface flatness. Moreover, relationships that describe the power lost due to the effect of each parameter are derived in this study.

Keywords: Fresnel lens, LLBG, solar concentrator, solar tracking

Procedia PDF Downloads 186
775 Offshore Power Transition Project

Authors: Kashmir Johal

Abstract:

Within a wider context of improving whole-life effectiveness of gas and oil fields, we have been researching how to generate power local to the wellhead. (Provision of external power to a subsea wellhead can be prohibitively expensive and results in uneconomic fields. This has been an oil/gas industry challenge for many years.) We have been developing a possible approach to “local” power generation and have been conducting technical, environmental, (and economic) research to develop a viable approach. We sought to create a workable design for a new type of power generation system that makes use of differential pressure that can exist between the sea surface and a gas (or oil reservoir). The challenge has not just been to design a system capable of generating power from potential energy but also to design it in such a way that it anticipates and deals with the wide range of technological, environmental, and chemical constraints faced in such environments. We believe this project shows the enormous opportunity in deriving clean, economic, and zero emissions renewable energy from offshore sources. Since this technology is not currently available, a patent has been filed to protect the advancement of this technology.

Keywords: renewable, energy, power, offshore

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774 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 507