Search results for: nonlinear systems
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 10338

Search results for: nonlinear systems

9468 Capillary Wave Motion and Atomization Induced by Surface Acoustic Waves under the Navier-Slip Condition at the Wall

Authors: Jaime E. Munoz, Jose C. Arcos, Oscar E. Bautista, Ivan E. Campos

Abstract:

The influence of slippage phenomenon over the destabilization and atomization mechanisms induced via surface acoustic waves on a Newtonian, millimeter-sized, drop deposited on a hydrophilic substrate is studied theoretically. By implementing the Navier-slip model and a lubrication-type approach into the equations which govern the dynamic response of a drop exposed to acoustic stress, a highly nonlinear evolution equation for the air-liquid interface is derived in terms of the acoustic capillary number and the slip coefficient. By numerically solving such an evolution equation, the Spatio-temporal deformation of the drop's free surface is obtained; in this context, atomization of the initial drop into micron-sized droplets is predicted at our numerical model once the acoustically-driven capillary waves reach a critical value: the instability length. Our results show slippage phenomenon at systems with partial and complete wetting favors the formation of capillary waves at the free surface, which traduces in a major volume of liquid being atomized in comparison to the no-slip case for a given time interval. In consequence, slippage at the wall possesses the capability to affect and improve the atomization rate for a drop exposed to a high-frequency acoustic field.

Keywords: capillary instability, lubrication theory, navier-slip condition, SAW atomization

Procedia PDF Downloads 155
9467 Status and Proposed Models of Backhauling System in Thailand

Authors: Tarathorn Podcharathitikull, Jirarat Teeravaraprug

Abstract:

Transportation cost is the highest cost in logistics cost of Thailand, and truck transportation is counted as about 90% of the overall transportation cost. The main problem of truck transportation is backhauling. Backhauling has become an attractive cost-saving approach in logistics. To explore such opportunities, this paper investigated the current backhauling systems in Thailand. It was found that the backhauling problem is attracted to both governmental agencies and private sector. They gave attempts to build backhauling systems. This paper investigated two systems built by governmental agencies and one by private sector. Moreover, based on the interviews with the system representatives and users, pros and cons of the systems were found. The obstacles and challenges were obtained. This paper finally proposed a conceptual model of to-be backhauling system in Thailand.

Keywords: backhauling system, backhauls, interview, Thailand

Procedia PDF Downloads 283
9466 Key Parameters Analysis of the Stirring Systems in the Optmization Procedures

Authors: T. Gomes, J. Manzi

Abstract:

The inclusion of stirring systems in the calculation and optimization procedures has been undergone a significant lack of attention, what it can reflect in the results because such systems provide an additional energy to the process, besides promote a better distribution of mass and energy. This is meaningful for the reactive systems, particularly for the Continuous Stirred Tank Reactor (CSTR), for which the key variables and parameters, as well as the operating conditions of stirring systems, can play a pivotal role and it has been showed in the literature that neglect these factors can lead to sub-optimal results. It is also well known that the sole use of the First Law of Thermodynamics as an optimization tool cannot yield satisfactory results, since the joint use of the First and Second Laws condensed into a procedure so-called entropy generation minimization (EGM) has shown itself able to drive the system towards better results. Therefore, the main objective of this paper is to determine the effects of key parameters of the stirring system in the optimization procedures by means of EGM applied to the reactive systems. Such considerations have been possible by dimensional analysis according to Rayleigh and Buckingham's method, which takes into account the physical and geometric parameters and the variables of the reactive system. For the simulation purpose based on the production of propylene glycol, the results have shown a significant increase in the conversion rate from 36% (not-optimized system) to 95% (optimized system) with a consequent reduction of by-products. In addition, it has been possible to establish the influence of the work of the stirrer in the optimization procedure, in which can be described as a function of the fluid viscosity and consequently of the temperature. The conclusions to be drawn also indicate that the use of the entropic analysis as optimization tool has been proved to be simple, easy to apply and requiring low computational effort.

Keywords: stirring systems, entropy, reactive system, optimization

Procedia PDF Downloads 244
9465 Transparency Obligations under the AI Act Proposal: A Critical Legal Analysis

Authors: Michael Lognoul

Abstract:

In April 2021, the European Commission released its AI Act Proposal, which is the first policy proposal at the European Union level to target AI systems comprehensively, in a horizontal manner. This Proposal notably aims to achieve an ecosystem of trust in the European Union, based on the respect of fundamental rights, regarding AI. Among many other requirements, the AI Act Proposal aims to impose several generic transparency obligationson all AI systems to the benefit of natural persons facing those systems (e.g. information on the AI nature of systems, in case of an interaction with a human). The Proposal also provides for more stringent transparency obligations, specific to AI systems that qualify as high-risk, to the benefit of their users, notably on the characteristics, capabilities, and limitations of the AI systems they use. Against that background, this research firstly presents all such transparency requirements in turn, as well as related obligations, such asthe proposed obligations on record keeping. Secondly, it focuses on a legal analysis of their scope of application, of the content of the obligations, and on their practical implications. On the scope of transparency obligations tailored for high-risk AI systems, the research notably notes that it seems relatively narrow, given the proposed legal definition of the notion of users of AI systems. Hence, where end-users do not qualify as users, they may only receive very limited information. This element might potentially raise concern regarding the objective of the Proposal. On the content of the transparency obligations, the research highlights that the information that should benefit users of high-risk AI systems is both very broad and specific, from a technical perspective. Therefore, the information required under those obligations seems to create, prima facie, an adequate framework to ensure trust for users of high-risk AI systems. However, on the practical implications of these transparency obligations, the research notes that concern arises due to potential illiteracy of high-risk AI systems users. They might not benefit from sufficient technical expertise to fully understand the information provided to them, despite the wording of the Proposal, which requires that information should be comprehensible to its recipients (i.e. users).On this matter, the research points that there could be, more broadly, an important divergence between the level of detail of the information required by the Proposal and the level of expertise of users of high-risk AI systems. As a conclusion, the research provides policy recommendations to tackle (part of) the issues highlighted. It notably recommends to broaden the scope of transparency requirements for high-risk AI systems to encompass end-users. It also suggests that principles of explanation, as they were put forward in the Guidelines for Trustworthy AI of the High Level Expert Group, should be included in the Proposal in addition to transparency obligations.

Keywords: aI act proposal, explainability of aI, high-risk aI systems, transparency requirements

Procedia PDF Downloads 311
9464 Dynamic Modelling of Hepatitis B Patient Using Sihar Model

Authors: Alakija Temitope Olufunmilayo, Akinyemi, Yagba Joy

Abstract:

Hepatitis is the inflammation of the liver tissue that can cause whiteness of the eyes (Jaundice), lack of appetite, vomiting, tiredness, abdominal pain, diarrhea. Hepatitis is acute if it resolves within 6 months and chronic if it last longer than 6 months. Acute hepatitis can resolve on its own, lead to chronic hepatitis or rarely result in acute liver failure. Chronic hepatitis may lead to scarring of the liver (Cirrhosis), liver failure and liver cancer. Modelling Hepatitis B may become necessary in order to reduce its spread. So, dynamic SIR model can be used. This model consists of a system of three coupled non-linear ordinary differential equation which does not have an explicit formula solution. It is an epidemiological model used to predict the dynamics of infectious disease by categorizing the population into three possible compartments. In this study, a five-compartment dynamic model of Hepatitis B disease was proposed and developed by adding control measure of sensitizing the public called awareness. All the mathematical and statistical formulation of the model, especially the general equilibrium of the model, was derived, including the nonlinear least square estimators. The initial parameters of the model were derived using nonlinear least square embedded in R code. The result study shows that the proportion of Hepatitis B patient in the study population is 1.4 per 1,000,000 populations. The estimated Hepatitis B induced death rate is 0.0108, meaning that 1.08% of the infected individuals die of the disease. The reproduction number of Hepatitis B diseases in Nigeria is 6.0, meaning that one individual can infect more than 6.0 people. The effect of sensitizing the public on the basic reproduction number is significant as the reproduction number is reduced. The study therefore recommends that programme should be designed by government and non-governmental organization to sensitize the entire Nigeria population in order to reduce cases of Hepatitis B disease among the citizens.

Keywords: hepatitis B, modelling, non-linear ordinary differential equation, sihar model, sensitization

Procedia PDF Downloads 88
9463 Inverted Umbrella-type Chiral Non-coplanar Ferrimagnetic Structure in Co(NO₃)₂

Authors: O. Maximova, I. L. Danilovich, E. B. Deeva, K. Y. Bukhteev, A. A. Vorobyova, I. V. Morozov, O. S. Volkova, E. A. Zvereva, I. V. Solovyev, S. A. Nikolaev, D. Phuyal, M. Abdel-Hafiez, Y. C. Wang, J. Y. Lin, J. M. Chen, D. I. Gorbunov, K. Puzniak, B. Lake, A. N. Vasiliev

Abstract:

The low-dimensional magnetic systems tend to reveal exotic spin liquid ground states or form peculiar types of long-range order. Among systems of vivid interest are those characterized by the triangular motif in two dimensions. The realization of either ordered or disordered ground state in a triangular, honeycomb, or kagome lattices is are dictated by the competition of exchange interactions, also being sensitive to anisotropy and the spin value of magnetic ions. While the low-spin Heisenberg systems may arrive at a spin liquid long-range entangled quantum state with emergent gauge structures, the high-spin Ising systems may establish the rigid non-collinear structures. This study presents the case of chiral non-coplanar inverted umbrella-type ferrimagnet formed in cobalt nitrate Co(NO₃)₂ below T

Keywords: chiral magnetic structures, low dimensional magnetic systems, umbrella-type ferrimagnets, chiral non-coplanar magnetic structures

Procedia PDF Downloads 124
9462 Incorporating Moving Authority Limits Into Driving Advice

Authors: Peng Zhou, Peter Pudney

Abstract:

Driver advice systems are used by many rail operators to help train drivers to improve timekeeping while minimising energy use. These systems typically operate independently of the safeworking system, because information on how far the train is allowed to travel -the “limit of authority"- is usually not available as real-time data that can be used when generating driving advice. This is not an issue when there is sufficient separation between trains. But on systems with low headways, driving advice could conflict with safeworking requirements. We describe a method for generating driving advice that takes into account a moving limit of authority that is communicated to the train in real-time. We illustrate the method with four simulated examples using data from the Zhengzhou Metro. The method will allow driver advice systems to be used more effectively on railways with low headways.

Keywords: railway transportation, energy efficient train operation, optimal train control, safe separation

Procedia PDF Downloads 6
9461 Polyurethane Membrane Mechanical Property Study for a Novel Carotid Covered Stent

Authors: Keping Zuo, Jia Yin Chia, Gideon Praveen Kumar Vijayakumar, Foad Kabinejadian, Fangsen Cui, Pei Ho, Hwa Liang Leo

Abstract:

Carotid artery is the major vessel supplying blood to the brain. Carotid artery stenosis is one of the three major causes of stroke and the stroke is the fourth leading cause of death and the first leading cause of disability in most developed countries. Although there is an increasing interest in carotid artery stenting for treatment of cervical carotid artery bifurcation therosclerotic disease, currently available bare metal stents cannot provide an adequate protection against the detachment of the plaque fragments over diseased carotid artery, which could result in the formation of micro-emboli and subsequent stroke. Our research group has recently developed a novel preferential covered-stent for carotid artery aims to prevent friable fragments of atherosclerotic plaques from flowing into the cerebral circulation, and yet retaining the ability to preserve the flow of the external carotid artery. The preliminary animal studies have demonstrated the potential of this novel covered-stent design for the treatment of carotid therosclerotic stenosis. The purpose of this study is to evaluate the biomechanical property of PU membrane of different concentration configurations in order to refine the stent coating technique and enhance the clinical performance of our novel carotid covered stent. Results from this study also provide necessary material property information crucial for accurate simulation analysis for our stents. Method: Medical grade Polyurethane (ChronoFlex AR) was used to prepare PU membrane specimens. Different PU membrane configurations were subjected to uniaxial test: 22%, 16%, and 11% PU solution were made by mixing the original solution with proper amount of the Dimethylacetamide (DMAC). The specimens were then immersed in physiological saline solution for 24 hours before test. All specimens were moistened with saline solution before mounting and subsequent uniaxial testing. The specimens were preconditioned by loading the PU membrane sample to a peak stress of 5.5 Mpa for 10 consecutive cycles at a rate of 50 mm/min. The specimens were then stretched to failure at the same loading rate. Result: The results showed that the stress-strain response curves of all PU membrane samples exhibited nonlinear characteristic. For the ultimate failure stress, 22% PU membrane was significantly higher than 16% (p<0.05). In general, our preliminary results showed that lower concentration PU membrane is stiffer than the higher concentration one. From the perspective of mechanical properties, 22% PU membrane is a better choice for the covered stent. Interestingly, the hyperelastic Ogden model is able to accurately capture the nonlinear, isotropic stress-strain behavior of PU membrane with R2 of 0.9977 ± 0.00172. This result will be useful for future biomechanical analysis of our stent designs and will play an important role for computational modeling of our covered stent fatigue study.

Keywords: carotid artery, covered stent, nonlinear, hyperelastic, stress, strain

Procedia PDF Downloads 308
9460 Reliable Consensus Problem for Multi-Agent Systems with Sampled-Data

Authors: S. H. Lee, M. J. Park, O. M. Kwon

Abstract:

In this paper, reliable consensus of multi-agent systems with sampled-data is investigated. By using a suitable Lyapunov-Krasovskii functional and some techniques such as Wirtinger Inequality, Schur Complement and Kronecker Product, the results of this systems are obtained by solving a set of Linear Matrix Inequalities(LMIs). One numerical example is included to show the effectiveness of the proposed criteria.

Keywords: multi-agent, linear matrix inequalities (LMIs), kronecker product, sampled-data, Lyapunov method

Procedia PDF Downloads 526
9459 The Cloud Systems Used in Education: Properties and Overview

Authors: Agah Tuğrul Korucu, Handan Atun

Abstract:

Diversity and usefulness of information that used in education are have increased due to development of technology. Web technologies have made enormous contributions to the distance learning system especially. Mobile systems, one of the most widely used technology in distance education, made much easier to access web technologies. Not bounding by space and time, individuals have had the opportunity to access the information on web. In addition to this, the storage of educational information and resources and accessing these information and resources is crucial for both students and teachers. Because of this importance, development and dissemination of web technologies supply ease of access to information and resources are provided by web technologies. Dynamic web technologies introduced as new technologies that enable sharing and reuse of information, resource or applications via the Internet and bring websites into expandable platforms are commonly known as Web 2.0 technologies. Cloud systems are one of the dynamic web technologies that defined as a model provides approaching the demanded information independent from time and space in appropriate circumstances and developed by NIST. One of the most important advantages of cloud systems is meeting the requirements of users directly on the web regardless of hardware, software, and dealing with install. Hence, this study aims at using cloud services in education and investigating the services provided by the cloud computing. Survey method has been used as research method. In the findings of this research the fact that cloud systems are used such studies as resource sharing, collaborative work, assignment submission and feedback, developing project in the field of education, and also, it is revealed that cloud systems have plenty of significant advantages in terms of facilitating teaching activities and the interaction between teacher, student and environment.

Keywords: cloud systems, cloud systems in education, online learning environment, integration of information technologies, e-learning, distance learning

Procedia PDF Downloads 347
9458 BER Estimate of WCDMA Systems with MATLAB Simulation Model

Authors: Suyeb Ahmed Khan, Mahmood Mian

Abstract:

Simulation plays an important role during all phases of the design and engineering of communications systems, from early stages of conceptual design through the various stages of implementation, testing, and fielding of the system. In the present paper, a simulation model has been constructed for the WCDMA system in order to evaluate the performance. This model describes multiusers effects and calculation of BER (Bit Error Rate) in 3G mobile systems using Simulink MATLAB 7.1. Gaussian Approximation defines the multi-user effect on system performance. BER has been analyzed with comparison between transmitting data and receiving data.

Keywords: WCDMA, simulations, BER, MATLAB

Procedia PDF Downloads 588
9457 Computational Simulations on Stability of Model Predictive Control for Linear Discrete-Time Stochastic Systems

Authors: Tomoaki Hashimoto

Abstract:

Model predictive control is a kind of optimal feedback control in which control performance over a finite future is optimized with a performance index that has a moving initial time and a moving terminal time. This paper examines the stability of model predictive control for linear discrete-time systems with additive stochastic disturbances. A sufficient condition for the stability of the closed-loop system with model predictive control is derived by means of a linear matrix inequality. The objective of this paper is to show the results of computational simulations in order to verify the validity of the obtained stability condition.

Keywords: computational simulations, optimal control, predictive control, stochastic systems, discrete-time systems

Procedia PDF Downloads 430
9456 Recognizing an Individual, Their Topic of Conversation and Cultural Background from 3D Body Movement

Authors: Gheida J. Shahrour, Martin J. Russell

Abstract:

The 3D body movement signals captured during human-human conversation include clues not only to the content of people’s communication but also to their culture and personality. This paper is concerned with automatic extraction of this information from body movement signals. For the purpose of this research, we collected a novel corpus from 27 subjects, arranged them into groups according to their culture. We arranged each group into pairs and each pair communicated with each other about different topics. A state-of-art recognition system is applied to the problems of person, culture, and topic recognition. We borrowed modeling, classification, and normalization techniques from speech recognition. We used Gaussian Mixture Modeling (GMM) as the main technique for building our three systems, obtaining 77.78%, 55.47%, and 39.06% from the person, culture, and topic recognition systems respectively. In addition, we combined the above GMM systems with Support Vector Machines (SVM) to obtain 85.42%, 62.50%, and 40.63% accuracy for person, culture, and topic recognition respectively. Although direct comparison among these three recognition systems is difficult, it seems that our person recognition system performs best for both GMM and GMM-SVM, suggesting that inter-subject differences (i.e. subject’s personality traits) are a major source of variation. When removing these traits from culture and topic recognition systems using the Nuisance Attribute Projection (NAP) and the Intersession Variability Compensation (ISVC) techniques, we obtained 73.44% and 46.09% accuracy from culture and topic recognition systems respectively.

Keywords: person recognition, topic recognition, culture recognition, 3D body movement signals, variability compensation

Procedia PDF Downloads 539
9455 Investigation of Flexural – Torsion Instability of Struts Using Modified Newmark Method

Authors: Seyed Amin Vakili, Sahar Sadat Vakili, Seyed Ehsan Vakili, Nader Abdoli Yazdi

Abstract:

Differential equations are of fundamental importance in engineering and applied mathematics, since many physical laws and relations appear mathematically in the form of such equations. The equilibrium state of structures consisting of one-dimensional elements can be described by an ordinary differential equation. The response of these kinds of structures under the loading, namely relationship between the displacement field and loading field, can be predicted by the solution of these differential equations and on satisfying the given boundary conditions. When the effect of change of geometry under loading is taken into account in modeling of equilibrium state, then these differential equations are partially integrable in quartered. They also exhibit instability characteristics when the structures are loaded compressively. The purpose of this paper is to represent the ability of the Modified Newmark Method in analyzing flexural-torsional instability of struts for both bifurcation and non-bifurcation structural systems. The results are shown to be very accurate with only a small number of iterations. The method is easily programmed, and has the advantages of simplicity and speeds of convergence and easily is extended to treat material and geometric nonlinearity including no prismatic members and linear and nonlinear spring restraints that would be encountered in frames. In this paper, these abilities of the method will be extended to the system of linear differential equations that govern strut flexural torsional stability.

Keywords: instability, torsion, flexural, buckling, modified newmark method stability

Procedia PDF Downloads 357
9454 Seismic Assessment of an Existing Dual System RC Buildings in Madinah City

Authors: Tarek M. Alguhane, Ayman H. Khalil, M. N. Fayed, Ayman M. Ismail

Abstract:

A 15-storey RC building, studied in this paper, is representative of modern building type constructed in Madina City in Saudi Arabia before 10 years ago. These buildings are almost consisting of reinforced concrete skeleton, i. e. columns, beams and flat slab as well as shear walls in the stairs and elevator areas arranged in the way to have a resistance system for lateral loads (wind–earthquake loads). In this study, the dynamic properties of the 15-storey RC building were identified using ambient motions recorded at several spatially-distributed locations within each building. After updating the mathematical models for this building with the experimental results, three dimensional pushover analysis (nonlinear static analysis) was carried out using SAP2000 software incorporating inelastic material properties for concrete, infill and steel. The effect of modeling the building with and without infill walls on the performance point as well as capacity and demand spectra due to EQ design spectrum function in Madina area has been investigated. The response modification factor (R) for the 15 storey RC building is evaluated from capacity and demand spectra (ATC-40). The purpose of this analysis is to evaluate the expected performance of structural systems by estimating, strength and deformation demands in design, and comparing these demands to available capacities at the performance levels of interest. The results are summarized and discussed.

Keywords: seismic assessment, pushover analysis, ambient vibration, modal update

Procedia PDF Downloads 389
9453 Software Engineering Revolution Driven by Complexity Science

Authors: Jay Xiong, Li Lin

Abstract:

This paper introduces a new software engineering paradigm based on complexity science, called NSE (Nonlinear Software Engineering paradigm). The purpose of establishing NSE is to help software development organizations double their productivity, half their cost, and increase the quality of their products in several orders of magnitude simultaneously. NSE complies with the essential principles of complexity science. NSE brings revolutionary changes to almost all aspects in software engineering. NSE has been fully implemented with its support platform Panorama++.

Keywords: complexity science, software development, software engineering, software maintenance

Procedia PDF Downloads 263
9452 Quantum Entanglement and Thermalization in Superconducting Two-Qubit Systems

Authors: E. Karami, M. Bohloul, P. Najmadi

Abstract:

The superconducting system is a suitable system for quantum computers. Quantum entanglement is a fundamental phenomenon that is key to the power of quantum computers. Quantum entanglement has been studied in different superconducting systems. In this paper, we are investigating a superconducting two-qubit system as a macroscopic system. These systems include two coupled Quantronium circuits. We calculate quantum entanglement and thermalization for system evolution and compare them. We observe, thermalization and entanglement have different behavior, and equilibrium thermal state has maximum entanglement.

Keywords: macroscopic system, quantum entanglement, thermalization, superconducting system

Procedia PDF Downloads 152
9451 Defining a Holistic Approach for Model-Based System Engineering: Paradigm and Modeling Requirements

Authors: Hycham Aboutaleb, Bruno Monsuez

Abstract:

Current systems complexity has reached a degree that requires addressing conception and design issues while taking into account all the necessary aspects. Therefore, one of the main challenges is the way complex systems are specified and designed. The exponential growing effort, cost and time investment of complex systems in modeling phase emphasize the need for a paradigm, a framework and a environment to handle the system model complexity. For that, it is necessary to understand the expectations of the human user of the model and his limits. This paper presents a generic framework for designing complex systems, highlights the requirements a system model needs to fulfill to meet human user expectations, and defines the refined functional as well as non functional requirements modeling tools needs to meet to be useful in model-based system engineering.

Keywords: system modeling, modeling language, modeling requirements, framework

Procedia PDF Downloads 529
9450 Practical Application of Business Processes Simulation

Authors: M. Gregušová, V. Schindlerová, I. Šajdlerová, P. Mohyla, J. Kedroň

Abstract:

Company managers are always looking for more and more opportunities to succeed in today's fiercely competitive market. Maintain your place among the successful companies on the market today or come up with a revolutionary business idea; it is much more difficult than before. Each new or improved method, tools, or the approach that can improve the functioning of business processes or even the entire system is worth checking and verification. The use of simulation in the design of manufacturing systems and their management in practice is one of the ways without increased risk to find the optimal parameters of manufacturing processes and systems. The paper presents an example of using simulation to solve the bottleneck problem in concrete company.

Keywords: practical applications, business processes, systems, simulation

Procedia PDF Downloads 636
9449 Stability of Hybrid Stochastic Systems

Authors: Manlika Ratchagit

Abstract:

This paper is concerned with robust mean square stability of uncertain stochastic switched discrete time-delay systems. The system to be considered is subject to interval time-varying delays, which allows the delay to be a fast time-varying function and the lower bound is not restricted to zero. Based on the discrete Lyapunov functional, a switching rule for the robust mean square stability for the uncertain stochastic discrete time-delay system is designed via linear matrix inequalities. Finally, some examples are exploited to illustrate the effectiveness of the proposed schemes.

Keywords: robust mean square stability, discrete-time stochastic systems, hybrid systems, interval time-varying delays, Lyapunov functional, linear matrix inequalities

Procedia PDF Downloads 483
9448 A Platform to Analyze Controllers for Solar Hot Water Systems

Authors: Aziz Ahmad, Guillermo Ramirez-Prado

Abstract:

Governments around the world encourage the use of solar water heating in residential houses due to the low maintenance requirements and efficiency of the solar collector water heating systems. The aim of this work is to study a domestic solar water heating system in a residential building to develop a model of the entire solar water heating system including flat-plate solar collector and storage tank. The proposed model is adaptable to any households and location. The model can be used to test different types of controllers and can provide efficiency as well as economic analysis. The proposed model is based on the heat and mass transfer equations along with assumptions applied in the model which can be modified for a variety of different solar water heating systems and sizes. Simulation results of the model were compared with the actual system which shows similar trends.

Keywords: solar thermal systems, solar water heating, solar collector model, hot water tank model, solar controllers

Procedia PDF Downloads 268
9447 New Results on Stability of Hybrid Stochastic Systems

Authors: Manlika Rajchakit

Abstract:

This paper is concerned with robust mean square stability of uncertain stochastic switched discrete time-delay systems. The system to be considered is subject to interval time-varying delays, which allows the delay to be a fast time-varying function and the lower bound is not restricted to zero. Based on the discrete Lyapunov functional, a switching rule for the robust mean square stability for the uncertain stochastic discrete time-delay system is designed via linear matrix inequalities. Finally, some examples are exploited to illustrate the effectiveness of the proposed schemes.

Keywords: robust mean square stability, discrete-time stochastic systems, hybrid systems, interval time-varying delays, lyapunov functional, linear matrix inequalities

Procedia PDF Downloads 428
9446 Augmentation of Automatic Selective Door Operation systems with UWB positioning

Authors: John Chan, Jake Linnenbank, Gavin Caird

Abstract:

Automatic Selective Door Operation (ASDO) systems are increasingly used in railways to provide Correct Side Door Enable (CSDE) protection as well as to protect passenger doors opening off the platform where the train is longer than the platform, or in overshoot or undershoot scenarios. Such ASDO systems typically utilise trackside-installed RFID beacons, such as Eurobalises for odometry positioning purposes. Installing such trackside infrastructure may not be desirable or possible due to various factors such as conflict with existing infrastructure, potential damage from track tamping and jurisdiction constraints. Ultra-wideband (UWB) positioning technology could enable ASDO positioning requirements to be met without requiring installation of equipment directly on track since UWB technology can be installed on adjacent infrastructure such as on platforms. This paper will explore the feasibility of upgrading existing ASDO systems with UWB positioning technology, the feasibility of retrofitting UWB-enabled ASDO systems onto unfitted trains, and any other considerations relating to the use of UWB positioning for ASDO applications.

Keywords: UWB, ASDO, automatic selective door operations, CSDE, correct side door enable

Procedia PDF Downloads 73
9445 HIS Integration Systems Using Modality Worklist and DICOM

Authors: Kulvinder Singh Mann

Abstract:

The usability and simulation of information systems, known as Hospital Information System (HIS), Radiology Information System (RIS), and Picture Archiving, Communication System, for electronic medical records has shown a good impact for actors in the hospital. The objective is to help and make their work easier; such as for a nurse or administration staff to record the medical records of the patient, and for a patient to check their bill transparently. However, several limitations still exists on such area regarding the type of data being stored in the system, ability for data transfer, storage and protocols to support communication between medical devices and digital images. This paper reports the simulation result of integrating several systems to cope with those limitations by using the Modality Worklist and DICOM standard. It succeeds in documenting the reason of that failure so future research will gain better understanding and be able to integrate those systems.

Keywords: HIS, RIS, PACS, modality worklist, DICOM, digital images

Procedia PDF Downloads 315
9444 A Study on Green Building Certification Systems within the Context of Anticipatory Systems

Authors: Taner Izzet Acarer, Ece Ceylan Baba

Abstract:

This paper examines green building certification systems and their current processes in comparison with anticipatory systems. Rapid growth of human population and depletion of natural resources are causing irreparable damage to urban and natural environment. In this context, the concept of ‘sustainable architecture’ has emerged in the 20th century so as to establish and maintain standards for livable urban spaces, to improve quality of urban life, and to preserve natural resources for future generations. The construction industry is responsible for a large part of the resource consumption and it is believed that the ‘green building’ designs that emerge in construction industry can reduce environmental problems and contribute to sustainable development around the world. A building must meet a specific set of criteria, set forth through various certification systems, in order to be eligible for designation as a green building. It is disputable whether methods used by green building certification systems today truly serve the purposes of creating a sustainable world. Accordingly, this study will investigate the sets of rating systems used by the most popular green building certification programs, including LEED (Leadership in Energy and Environmental Design), BREEAM (Building Research Establishment's Environmental Assessment Methods), DGNB (Deutsche Gesellschaft für Nachhaltiges Bauen System), in terms of ‘Anticipatory Systems’ in accordance with the certification processes and their goals, while discussing their contribution to architecture. The basic methodology of the study is as follows. Firstly analyzes of brief historical and literature review of green buildings and certificate systems will be stated. Secondly, processes of green building certificate systems will be disputed by the help of anticipatory systems. Anticipatory Systems is a set of systems designed to generate action-oriented projections and to forecast potential side effects using the most current data. Anticipatory Systems pull the future into the present and take action based on future predictions. Although they do not have a claim to see into the future, they can provide foresight data. When shaping the foresight data, Anticipatory Systems use feedforward instead of feedback, enabling them to forecast the system’s behavior and potential side effects by establishing a correlation between the system’s present/past behavior and projected results. This study indicates the goals and current status of LEED, BREEAM and DGNB rating systems that created by using the feedback technique will be examined and presented in a chart. In addition, by examining these rating systems with the anticipatory system that using the feedforward method, the negative influences of the potential side effects on the purpose and current status of the rating systems will be shown in another chart. By comparing the two obtained data, the findings will be shown that rating systems are used for different goals than the purposes they are aiming for. In conclusion, the side effects of green building certification systems will be stated by using anticipatory system models.

Keywords: anticipatory systems, BREEAM, certificate systems, DGNB, green buildings, LEED

Procedia PDF Downloads 219
9443 Modeling and System Identification of a Variable Excited Linear Direct Drive

Authors: Heiko Weiß, Andreas Meister, Christoph Ament, Nils Dreifke

Abstract:

Linear actuators are deployed in a wide range of applications. This paper presents the modeling and system identification of a variable excited linear direct drive (LDD). The LDD is designed based on linear hybrid stepper technology exhibiting the characteristic tooth structure of mover and stator. A three-phase topology provides the thrust force caused by alternating strengthening and weakening of the flux of the legs. To achieve best possible synchronous operation, the phases are commutated sinusoidal. Despite the fact that these LDDs provide high dynamics and drive forces, noise emission limits their operation in calm workspaces. To overcome this drawback an additional excitation of the magnetic circuit is introduced to LDD using additional enabling coils instead of permanent magnets. The new degree of freedom can be used to reduce force variations and related noise by varying the excitation flux that is usually generated by permanent magnets. Hence, an identified simulation model is necessary to analyze the effects of this modification. Especially the force variations must be modeled well in order to reduce them sufficiently. The model can be divided into three parts: the current dynamics, the mechanics and the force functions. These subsystems are described with differential equations or nonlinear analytic functions, respectively. Ordinary nonlinear differential equations are derived and transformed into state space representation. Experiments have been carried out on a test rig to identify the system parameters of the complete model. Static and dynamic simulation based optimizations are utilized for identification. The results are verified in time and frequency domain. Finally, the identified model provides a basis for later design of control strategies to reduce existing force variations.

Keywords: force variations, linear direct drive, modeling and system identification, variable excitation flux

Procedia PDF Downloads 368
9442 Basics of SCADA Security: A Technical Approach

Authors: Michał Witas

Abstract:

This paper presents a technical approach to analysis of security of SCADA systems. Main goal of the paper is to make SCADA administrators aware of risks resulting from SCADA systems usage and to familiarize with methods that can be adopt to existing or planned system, to increase overall system security level. Because SCADA based systems become a industrial standard, more attention should be paid to the security of that systems. Industrial Control Systems (ICS) like SCADA are responsible for controlling crucial aspects of wide range of industrial processes. In pair with that responsibility, goes a lot of money that can be earned or lost – this fact is main reason of increased interest of attackers. Additionally ICS are often responsible for maintaining resources strategic from the point of view of national economy, like electricity (including nuclear power plants), heating, water resources or military facilities, so they can be targets of terrorist cybernetic attacks. Without proper risk analysis and management, vulnerabilities resulting from the usage of SCADA can be easily exploited by potential attacker. Paper is based mostly on own experience in systems security, gathered during academic studies and professional work in international company. As title suggests, it will cover only basics of topic, because every of points mentioned in the document can be base for additional research and papers.

Keywords: denial of service, SCADA, security policy, distributed network

Procedia PDF Downloads 370
9441 Pros and Cons of Different Types of Irrigation Systems for Date Palm Production in Sebha, Libya

Authors: Ahmad Aridah, Maria Fay Rola-Rubzen, Zora Singh

Abstract:

This study investigated the effectiveness of various types of irrigation systems in regards to the impact that these have on the productivity of date palms in the semi-arid and arid region of Sebha, Southwest Libya. The date palm is an economically important crop in Libya and contributes to the agriculture industry, foreign exchange earnings, farmers’ income, and employment in the country. The date palm industry relies on large amounts of water for growing the crop. Farmers in Southwest Libya use a variety of irrigation systems, but the quality and quantity of water varies between systems and this affects the productivity and income of farmers. Using survey data from 210 farmers, this study estimated and assessed the pros and cons of different types of irrigation systems for date palm production under various irrigation systems currently used in Sebha, Libya. The number of years farmers have used irrigation, the area, irrigation water consumption, time of irrigation, number of farm workers (including family labour) and inputs used were measured for surface, sprinkler and drip irrigation methods. Findings from this research provide new insights into the advantages and disadvantages of the various irrigation systems, problems encountered by farmers and the factors that affect the quality and quantity of the irrigation system. The paper discussed proposed solutions to deal with the problems including timing of irrigation, canal maintenance, repair of wells and water control.

Keywords: Libya, factors, irrigation method, date palm

Procedia PDF Downloads 348
9440 Development of Fuzzy Logic and Neuro-Fuzzy Surface Roughness Prediction Systems Coupled with Cutting Current in Milling Operation

Authors: Joseph C. Chen, Venkata Mohan Kudapa

Abstract:

Development of two real-time surface roughness (Ra) prediction systems for milling operations was attempted. The systems used not only cutting parameters, such as feed rate and spindle speed, but also the cutting current generated and corrected by a clamp type energy sensor. Two different approaches were developed. First, a fuzzy inference system (FIS), in which the fuzzy logic rules are generated by experts in the milling processes, was used to conduct prediction modeling using current cutting data. Second, a neuro-fuzzy system (ANFIS) was explored. Neuro-fuzzy systems are adaptive techniques in which data are collected on the network, processed, and rules are generated by the system. The inference system then uses these rules to predict Ra as the output. Experimental results showed that the parameters of spindle speed, feed rate, depth of cut, and input current variation could predict Ra. These two systems enable the prediction of Ra during the milling operation with an average of 91.83% and 94.48% accuracy by FIS and ANFIS systems, respectively. Statistically, the ANFIS system provided better prediction accuracy than that of the FIS system.

Keywords: surface roughness, input current, fuzzy logic, neuro-fuzzy, milling operations

Procedia PDF Downloads 145
9439 Enhancing Vehicle Efficiency Through Vapor Absorption Refrigeration Systems

Authors: Yoftahe Nigussie Worku

Abstract:

This paper explores the utilization of vapor absorption refrigeration systems (VARS) as an alternative to the conventional vapor compression refrigerant systems (VCRS) in vehicle air conditioning (AC) systems. Currently, most vehicles employ VCRS, which relies on engine power to drive the compressor, leading to additional fuel consumption. In contrast, VARS harnesses low-grade heat, specifically from the exhaust of high-power internal combustion engines, reducing the burden on the vehicle's engine. The historical development of vapor absorption technology is outlined, dating back to Michael Faraday's discovery in 1824 and the subsequent creation of the first vapor absorption refrigeration machine by Ferdinand Carre in 1860. The paper delves into the fundamental principles of VARS, emphasizing the replacement of mechanical processes with physicochemical interactions, utilizing heat rather than mechanical work. The study compares the basic concepts of the current vapor compression systems with the proposed vapor absorption systems, highlighting the efficiency gains achieved by eliminating the need for engine-driven compressors. The vapor absorption refrigeration cycle (VARC) is detailed, focusing on the generator's role in separating and vaporizing ammonia, chosen for its low-temperature evaporation characteristics. The project's statement underscores the need for increased efficiency in vehicle AC systems beyond the limitations of VCRS. By introducing VARS, driven by low-grade heat, the paper advocates for a reduction in engine power consumption and, consequently, a decrease in fuel usage. This research contributes to the ongoing efforts to enhance sustainability and efficiency in automotive climate control systems.

Keywords: VCRS, VARS, efficiency, sustainability

Procedia PDF Downloads 72