Search results for: flexible lamina
628 Identification and Force Control of a Two Chambers Pneumatic Soft Actuator
Authors: Najib K. Dankadai, Ahmad 'Athif Mohd Faudzi, Khairuddin Osman, Muhammad Rusydi Muhammad Razif, IIi Najaa Aimi Mohd Nordin
Abstract:
Researches in soft actuators are now growing rapidly because of their adequacy to be applied in sectors like medical, agriculture, biological and welfare. This paper presents system identification (SI) and control of the force generated by a two chambers pneumatic soft actuator (PSA). A force mathematical model for the actuator was identified experimentally using data acquisition card and MATLAB SI toolbox. Two control techniques; a predictive functional control (PFC) and conventional proportional integral and derivative (PID) schemes are proposed and compared based on the identified model for the soft actuator flexible mechanism. Results of this study showed that both of the proposed controllers ensure accurate tracking when the closed loop system was tested with the step, sinusoidal and multi step reference input through MATLAB simulation although the PFC provides a better response than the PID.Keywords: predictive functional control (PFC), proportional integral and derivative (PID), soft actuator, system identification
Procedia PDF Downloads 314627 Flexible Cities: A Multisided Spatial Application of Tracking Livability of Urban Environment
Authors: Maria Christofi, George Plastiras, Rafaella Elia, Vaggelis Tsiourtis, Theocharis Theocharides, Miltiadis Katsaros
Abstract:
The rapidly expanding urban areas of the world constitute a challenge of how we need to make the transition to "the next urbanization", which will be defined by new analytical tools and new sources of data. This paper is about the production of a spatial application, the ‘FUMapp’, where space and its initiative will be available literally, in meters, but also abstractly, at a sensed level. While existing spatial applications typically focus on illustrations of the urban infrastructure, the suggested application goes beyond the existing: It investigates how our environment's perception adapts to the alterations of the built environment through a dataset construction of biophysical measurements (eye-tracking, heart beating), and physical metrics (spatial characteristics, size of stimuli, rhythm of mobility). It explores the intersections between architecture, cognition, and computing where future design can be improved and identifies the flexibility and livability of the ‘available space’ of specific examined urban paths.Keywords: biophysical data, flexibility of urban, livability, next urbanization, spatial application
Procedia PDF Downloads 134626 Privacy-Preserving Location Sharing System with Client/Server Architecture in Mobile Online Social Network
Authors: Xi Xiao, Chunhui Chen, Xinyu Liu, Guangwu Hu, Yong Jiang
Abstract:
Location sharing is a fundamental service in mobile Online Social Networks (mOSNs), which raises significant privacy concerns in recent years. Now, most location-based service applications adopt client/server architecture. In this paper, a location sharing system, named CSLocShare, is presented to provide flexible privacy-preserving location sharing with client/server architecture in mOSNs. CSLocShare enables location sharing between both trusted social friends and untrusted strangers without the third-party server. In CSLocShare, Location-Storing Social Network Server (LSSNS) provides location-based services but do not know the users’ real locations. The thorough analysis indicates that the users’ location privacy is protected. Meanwhile, the storage and the communication cost are saved. CSLocShare is more suitable and effective in reality.Keywords: mobile online social networks, client/server architecture, location sharing, privacy-preserving
Procedia PDF Downloads 315625 Finite Element Simulation for Preliminary Study on Microorganism Detection System
Authors: Muhammad Rosli Abdullah, Noor Hasmiza Harun
Abstract:
A microorganism detection system has a potential to be used with the advancement in a biosensor development. The detection system requires an optical sensing system, microfluidic device and biological reagent. Although, the biosensors are available in the market, a label free and a lab-on-chip approach will promote a flexible solution. As a preliminary study of microorganism detection, three mechanisms such as Total Internal Reflection (TIR), Micro Fluidic Channel (MFC) and magnetic-electric field propagation were study and simulated. The objective are to identify the TIR angle, MFC parabolic flow and the wavelength for the microorganism detection. The simulation result indicates that evanescent wave is achieved when TIR angle > 42°, the corner and centre of a parabolic velocity are 0.02 m/s and 0.06 m/s respectively, and a higher energy distribution of a perfect electromagnetic scattering with dipole resonance radiation occurs at 500 nm. This simulation is beneficial to determine the components of the microorganism detection system that does not rely on classical microbiological, immunological and genetic methods which are laborious, time-consuming procedures and confined to specialized laboratories with expensive instrumentation equipment.Keywords: microorganism, microfluidic, total internal reflection, lab on chip
Procedia PDF Downloads 264624 Fluid Structure Interaction of Flow and Heat Transfer around a Microcantilever
Authors: Khalil Khanafer
Abstract:
This study emphasizes on analyzing the effect of flow conditions and the geometric variation of the microcantilever’s bluff body on the microcantilever detection capabilities within a fluidic device using a finite element fluid-structure interaction model. Such parameters include inlet velocity, flow direction, and height of the microcantilever’s supporting system within the fluidic cell. The transport equations are solved using a finite element formulation based on the Galerkin method of weighted residuals. For a flexible microcantilever, a fully coupled fluid-structure interaction (FSI) analysis is utilized and the fluid domain is described by an Arbitrary-Lagrangian–Eulerian (ALE) formulation that is fully coupled to the structure domain. The results of this study showed a profound effect on the magnitude and direction of the inlet velocity and the height of the bluff body on the deflection of the microcantilever. The vibration characteristics were also investigated in this study. This work paves the road for researchers to design efficient microcantilevers that display least errors in the measurements.Keywords: fluidic cell, FSI, microcantilever, flow direction
Procedia PDF Downloads 367623 All Solution-Processed Organic Light Emitting Diode with Low Melting Point Alloy Encapsulation
Authors: Geon Bae, Cheol Hee Moon
Abstract:
Organic Light Emitting Diodes (OLEDs) are being developed rapidly as next-generation displays due to their self-luminous and flexible characteristics. OLEDs are highly susceptible to moisture and oxygen due to their structural properties. Thus, requiring a high level of encapsulation technology. Recently, encapsulation technology such as Thin Film Encapsulation (TFE) has been developed for OLED, but it is not perfect to prevent moisture permeation on the side. In this study, we propose OLED encapsulation method using Low melting Point Alloy (LMPA). The LMPA line was designed in square box shape on the outer edge of the device and was formed by screen printing method. To determine if LMPA has an effect on OLED, we fabricated solution processed OLEDs with a square-shaped LMPA line and evaluate the I-V-L characteristics of the OLEDs. Also, the resistance characteristic of the LMPA line was observed by repeatedly bending the LMPA line. It is expected that LMPA encapsulation will have a great advantage in shortening the process time and cost reduction.Keywords: OLED, encapsulation, LMPA, solution process
Procedia PDF Downloads 237622 The Effect of Nanoclay on Long Term Performance of Asphalt Concrete Pavement
Authors: A. Khodadadi, Hasani, Salehi
Abstract:
The advantages of using modified asphalt binders are widely recognized—primarily, improved rutting resistance, reduced fatigue cracking and less cold-temperature cracking. Nanoclays are known to enhance the properties of many polymers. Nanoclays are used to improve modulus and tensile strength, flame resistance and thermal and structural properties of many materials. This paper intends to investigate the application and development of nano-technological concepts for bituminous materials and asphalt pavements. The application of nano clay on the fatigue life of asphalt pavement have not been yet thoroughly understood. In this research, two type of highway asphalt materials, dense Marshall specimens, with 2% nano clay and without nano clay, were employed for the fatigue behavior of the asphalt pavement.The effect of nano additive on the performance of flexible pavements has been investigated through the indirect tensile test for the samples prepared with 2% nano clay and without nano clay in four stress levels from 200–500 kPa. The primary results indicated samples with 2% nano clay have almost double or even more fatigue life in most of stress levels.Keywords: Nano clay, Asphalt, fatigue life, pavement
Procedia PDF Downloads 443621 Anomalous Behaviors of Visible Luminescence from Graphene Quantum Dots
Authors: Hyunho Shin, Jaekwang Jung, Jeongho Park, Sungwon Hwang
Abstract:
For the application of graphene quantum dots (GQDs) to optoelectronic nanodevices, it is of critical importance to understand the mechanisms which result in novel phenomena of their light absorption/emission. The optical transitions are known to be available up to ~6 eV in GQDs, especially useful for ultraviolet (UV) photodetectors (PDs). Here, we present size-dependent shape/edge-state variations of GQDs and visible photoluminescence (PL) showing anomalous size dependencies. With varying the average size (da) of GQDs from 5 to 35 nm, the peak energy of the absorption spectra monotonically decreases, while that of the visible PL spectra unusually shows nonmonotonic behaviors having a minimum at diameter ∼17 nm. The PL behaviors can be attributed to the novel feature of GQDs, that is, the circular-to-polygonal-shape and corresponding edge-state variations of GQDs at diameter ∼17 nm as the GQD size increases, as demonstrated by high resolution transmission electron microscopy. We believe that such a comprehensive scheme in designing device architecture and the structural formulation of GQDs provides a device for practical realization of environmentally benign, high performance flexible devices in the future.Keywords: graphene, quantum dot, size, photoluminescence
Procedia PDF Downloads 284620 Feature-Based Summarizing and Ranking from Customer Reviews
Authors: Dim En Nyaung, Thin Lai Lai Thein
Abstract:
Due to the rapid increase of Internet, web opinion sources dynamically emerge which is useful for both potential customers and product manufacturers for prediction and decision purposes. These are the user generated contents written in natural languages and are unstructured-free-texts scheme. Therefore, opinion mining techniques become popular to automatically process customer reviews for extracting product features and user opinions expressed over them. Since customer reviews may contain both opinionated and factual sentences, a supervised machine learning technique applies for subjectivity classification to improve the mining performance. In this paper, we dedicate our work is the task of opinion summarization. Therefore, product feature and opinion extraction is critical to opinion summarization, because its effectiveness significantly affects the identification of semantic relationships. The polarity and numeric score of all the features are determined by Senti-WordNet Lexicon. The problem of opinion summarization refers how to relate the opinion words with respect to a certain feature. Probabilistic based model of supervised learning will improve the result that is more flexible and effective.Keywords: opinion mining, opinion summarization, sentiment analysis, text mining
Procedia PDF Downloads 321619 An Inviscid Compressible Flow Solver Based on Unstructured OpenFOAM Mesh Format
Authors: Utkan Caliskan
Abstract:
Two types of numerical codes based on finite volume method are developed in order to solve compressible Euler equations to simulate the flow through forward facing step channel. Both algorithms have AUSM+- up (Advection Upstream Splitting Method) scheme for flux splitting and two-stage Runge-Kutta scheme for time stepping. In this study, the flux calculations differentiate between the algorithm based on OpenFOAM mesh format which is called 'face-based' algorithm and the basic algorithm which is called 'element-based' algorithm. The face-based algorithm avoids redundant flux computations and also is more flexible with hybrid grids. Moreover, some of OpenFOAM’s preprocessing utilities can be used on the mesh. Parallelization of the face based algorithm for which atomic operations are needed due to the shared memory model, is also presented. For several mesh sizes, 2.13x speed up is obtained with face-based approach over the element-based approach.Keywords: cell centered finite volume method, compressible Euler equations, OpenFOAM mesh format, OpenMP
Procedia PDF Downloads 310618 Efficient GIS Based Public Health System for Disease Prevention
Authors: K. M. G. T. R. Waidyarathna, S. M. Vidanagamachchi
Abstract:
Public Health System exists in Sri Lanka has a satisfactory complete information flow when compared to other systems in developing countries. The availability of a good health information system contributed immensely to achieve health indices that are in line with the developed countries like US and UK. The health information flow at the moment is completely paper based. In Sri Lanka, the fields like banking, accounting and engineering have incorporated information and communication technology to the same extent that can be observed in any other country. The field of medicine has behind those fields throughout the world mainly due to its complexity, issues like privacy, confidentially and lack of people with knowledge in both fields of Information Technology (IT) and Medicine. Sri Lanka’s situation is much worse and the gap is rapidly increasing with huge IT initiatives by private-public partnerships in all other countries. The major goal of the framework is to support minimizing the spreading diseases. To achieve that a web based framework should be implemented for this application domain with web mapping. The aim of this GIS based public health system is a secure, flexible, easy to maintain environment for creating and maintaining public health records and easy to interact with relevant parties.Keywords: DHIS2, GIS, public health, Sri Lanka
Procedia PDF Downloads 556617 Green Building for Positive Energy Districts in European Cities
Authors: Paola Clerici Maestosi
Abstract:
Positive Energy District (PED) is a rather recent concept whose aim is to contribute to the main objectives of the Energy Union strategy. It is based on an integrated multi-sectoral approach in response to Europe's most complex challenges. PED integrates energy efficiency, renewable energy production, and energy flexibility in an integrated, multi-sectoral approach at the city level. The core idea behind Positive Energy Districts (PEDs) is to establish an urban area that can generate more energy than it consumes. Additionally, it should be flexible enough to adapt to changes in the energy market. This is crucial because a PED's goal is not just to achieve an annual surplus of net energy but also to help reduce the impact on the interconnected centralized energy networks. It achieves this by providing options to increase on-site load matching and self-consumption, employing technologies for short- and long-term energy storage, and offering energy flexibility through smart control. Thus, it seems that PEDs can encompass all types of buildings in the city environment. Given this which is the added value of having green buildings being constitutive part of PEDS? The paper will present a systematic literature review identifying the role of green building in Positive Energy District to provide answer to following questions: (RQ1) the state of the art of PEDs implementation; (RQ2) penetration of green building in Positive Energy District selected case studies. Methodological approach is based on a broad holistic study of bibliographic sources according to Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) further data will be analysed, mapped and text mining through VOSviewer. Main contribution of research is a cognitive framework on Positive Energy District in Europe and a selection of case studies where green building supported the transition to PED. The inclusion of green buildings within Positive Energy Districts (PEDs) adds significant value for several reasons. Firstly, green buildings are designed and constructed with a focus on environmental sustainability, incorporating energy-efficient technologies, materials, and design principles. As integral components of PEDs, these structures contribute directly to the district's overall ability to generate more energy than it consumes. Secondly, green buildings typically incorporate renewable energy sources, such as solar panels or wind turbines, further boosting the district's capacity for energy generation. This aligns with the PED objective of achieving a surplus of net energy. Moreover, green buildings often feature advanced systems for on-site energy management, load-matching, and self-consumption. This enhances the PED's capability to respond to variations in the energy market, making the district more agile and flexible in optimizing energy use. Additionally, the environmental considerations embedded in green buildings align with the broader sustainability goals of PEDs. By reducing the ecological footprint of individual structures, PEDs with green buildings contribute to minimizing the overall impact on centralized energy networks and promote a more sustainable urban environment. In summary, the incorporation of green buildings within PEDs not only aligns with the district's energy objectives but also enhances environmental sustainability, energy efficiency, and the overall resilience of the urban environment.Keywords: positive energy district, renewables energy production, energy flexibility, energy efficiency
Procedia PDF Downloads 34616 Rotor Dynamic Analysis for a Shaft Train by Using Finite Element Method
Authors: M. Najafi
Abstract:
In the present paper, a large turbo-generator shaft train including a heavy-duty gas turbine engine, a coupling, and a generator is established. The method of analysis is based on finite element simplified model for lateral and torsional vibration calculation. The basic elements of rotor are the shafts and the disks which are represented as circular cross section flexible beams and rigid body elements, respectively. For more accurate results, the gyroscopic effect and bearing dynamics coefficients and function of rotation are taken into account, and for the influence of shear effect, rotor has been modeled in the form of Timoshenko beam. Lateral critical speeds, critical speed map, damped mode shapes, Campbell diagram, zones of instability, amplitudes, phase angles response due to synchronous forces of excitation and amplification factor are calculated. Also, in the present paper, the effect of imbalanced rotor and effects of changing in internal force and temperature are studied.Keywords: rotor dynamic analysis, finite element method, shaft train, Campbell diagram
Procedia PDF Downloads 132615 Planning Method Study on the Ecological Restrained Construction Area from the Perspective of Governance: A Case from Yangzijin, Yangzhou, China
Authors: Rushi Tan, Yilun Xu, Xiaohui Wang
Abstract:
The restrained construction zoning, an important part in the urban master plan, is a necessary planning tool to control the city sprawl, to guarantee the reservation implementation of the various types of protective elements, and to realize the storage of the essential urban spatial resources. Simultaneously, owing to the diverse constitutes of restrained construction area and the various stakeholders involved in, its planning requires an overall consideration of all elements from the perspective of coordination, balance and practicability to deal with the problems and conflicts in this process. Taking Yangzijin Ecological Restrained Construction Area in Yangzhou as an example, this study analyzes all the potential actors, agencies and stakeholders in this restrained construction area, as well as the relevant conflicts between each other. Besides, this study tries to build up a planning procedure based on the framework of governance theory, and proposes a possible planning method that combines "rigidity" and "flexibility" to protect the ecological limitation boundary, to take every interest into account, and to promote economic development in a harmonious society.Keywords: restrained construction area, governance, stakeholder, flexible stratagem, China
Procedia PDF Downloads 403614 An Adaptive Virtual Desktop Service in Cloud Computing Platform
Authors: Shuen-Tai Wang, Hsi-Ya Chang
Abstract:
Cloud computing is becoming more and more matured over the last few years and consequently the demands for better cloud services is increasing rapidly. One of the research topics to improve cloud services is the desktop computing in virtualized environment. This paper aims at the development of an adaptive virtual desktop service in cloud computing platform based on our previous research on the virtualization technology. We implement cloud virtual desktop and application software streaming technology that make it possible for providing Virtual Desktop as a Service (VDaaS). Given the development of remote desktop virtualization, it allows shifting the user’s desktop from the traditional PC environment to the cloud-enabled environment, which is stored on a remote virtual machine rather than locally. This proposed effort has the potential to positively provide an efficient, resilience and elastic environment for online cloud service. Users no longer need to burden the platform maintenances and drastically reduces the overall cost of hardware and software licenses. Moreover, this flexible remote desktop service represents the next significant step to the mobile workplace, and it lets users access their desktop environments from virtually anywhere.Keywords: cloud computing, virtualization, virtual desktop, VDaaS
Procedia PDF Downloads 277613 Impact of Flexibility on Residential Buildings in Egypt
Authors: Aly Mohamed El Husseiny, Azza Ezz Abdelkader
Abstract:
There is a critical thin line between freedom of choice and randomness. The distance between imagination and perception and between perception and execution varies depending on numerous factors. While in developed areas residents have the opportunity and abilities to build flexible homes, residents in developing areas create their own dwellings in informal settlements, even though none of them is comfortable at home in the long run. This paper explores three factors: What residents really need, what they do with limited flexibility, and what they do when there are no limits, as in the case of informal settlements. This paper studies alteration to residential buildings and how they connect to the changes in people’s lifecycle in all past cases. This study also examines all approaches to flexibility, focusing on a social approach. The results of this study are based on three practical studies: Interviews with residents in an informal settlement (Eshash Mahfouz in Minya in Egypt), a civil study of buildings in a middle-class district, and a survey of residents from many countries, including Egypt, and interviews with a number of them to determine residents’ needs and the extent of renovations they made or would like to make to their homes.Keywords: flexibility, housing, freedom of choice, social, changes, residents
Procedia PDF Downloads 289612 Through Integrated Project Management and Systems Engineering to Support System Design Development: A Project Management-based Systems Engineering Approach
Authors: Xiaojing Gao, James Njuguna
Abstract:
This paper emphasizes the importance of integrating project management and systems engineering for innovative system design and production development. The research highlights the need for a flexible approach that unifies these disciplines, as their isolation often leads to communication challenges and complexity within multidisciplinary teams. The paper aims to elucidate the intricate relationship between project management and systems engineering, recommending the consolidation of engineering disciplines into a single lifecycle for improved support of the design and development process. The research identifies a synergy between these disciplines, focusing on streamlining information communication during product design and development. The insights gained from this process can lead to product design optimization. Additionally, the paper introduces a proposed Project Management-Based Systems Engineering (PMBSE) framework, emphasizing effective communication, efficient processes, and advanced tools to enhance product development outcomes within the product lifecycle.Keywords: system engineering, product design and development, project management, cross-disciplinary
Procedia PDF Downloads 60611 A Nonlinear Dynamical System with Application
Authors: Abdullah Eqal Al Mazrooei
Abstract:
In this paper, a nonlinear dynamical system is presented. This system is a bilinear class. The bilinear systems are very important kind of nonlinear systems because they have many applications in real life. They are used in biology, chemistry, manufacturing, engineering, and economics where linear models are ineffective or inadequate. They have also been recently used to analyze and forecast weather conditions. Bilinear systems have three advantages: First, they define many problems which have a great applied importance. Second, they give us approximations to nonlinear systems. Thirdly, they have a rich geometric and algebraic structures, which promises to be a fruitful field of research for scientists and applications. The type of nonlinearity that is treated and analyzed consists of bilinear interaction between the states vectors and the system input. By using some properties of the tensor product, these systems can be transformed to linear systems. But, here we discuss the nonlinearity when the state vector is multiplied by itself. So, this model will be able to handle evolutions according to the Lotka-Volterra models or the Lorenz weather models, thus enabling a wider and more flexible application of such models. Here we apply by using an estimator to estimate temperatures. The results prove the efficiency of the proposed system.Keywords: Lorenz models, nonlinear systems, nonlinear estimator, state-space model
Procedia PDF Downloads 247610 Vibrotactility: Exploring and Prototyping the Aesthetics and Technology of Vibrotactility
Authors: Elsa Kosmack Vaara, Cheryl Akner Koler, Yusuf Mulla, Parivash Ranjbar, Anneli Nöu
Abstract:
This transdisciplinary research weaves together an aesthetic perspective with a technical one to develop human sensitivity for vibration and construct flexible, wearable devices that are miniature, lightweight, and energy efficient. By applying methods from artistic research, performative arts, audio science, nanotechnology, and interaction design, we created working prototypes with actuators that were specifically positioned in various places on the body. The vibrotactile prototypes were tested by our research team, design students, and people with deafblindness and blindness, each with different intentions. Some tests supported connoisseurship for vibrotactile musical expression. Others aimed for precise navigational instructions. Our results and discussion concern problems in establishing standards for vibrotactility because standards minimize diversity and narrow possible ways vibration can be experienced. Human bodies vary significantly in ‘where’ vibrotactile signals can be sensed and ‘how’ they awaken emotions. We encourage others to embrace the dynamic exchange between new haptic technology and aesthetic complexity.Keywords: aesthetics, vibration, music, interaction design, deafblindness
Procedia PDF Downloads 79609 A New Distributed Computing Environment Based On Mobile Agents for Massively Parallel Applications
Authors: Fatéma Zahra Benchara, Mohamed Youssfi, Omar Bouattane, Hassan Ouajji, Mohamed Ouadi Bensalah
Abstract:
In this paper, we propose a new distributed environment for High Performance Computing (HPC) based on mobile agents. It allows us to perform parallel programs execution as distributed one over a flexible grid constituted by a cooperative mobile agent team works. The distributed program to be performed is encapsulated on team leader agent which deploys its team workers as Agent Virtual Processing Unit (AVPU). Each AVPU is asked to perform its assigned tasks and provides the computational results which make the data and team works tasks management difficult for the team leader agent and that influence the performance computing. In this work we focused on the implementation of the Mobile Provider Agent (MPA) in order to manage the distribution of data and instructions and to ensure a load balancing model. It grants also some interesting mechanisms to manage the others computing challenges thanks to the mobile agents several skills.Keywords: image processing, distributed environment, mobile agents, parallel and distributed computing
Procedia PDF Downloads 395608 Project Paulina: A Human-Machine Interface for Individuals with Limited Mobility and Conclusions from Research and Development
Authors: Radoslaw Nagay
Abstract:
The Paulina Project aims to address the challenges faced by immobilized individuals, such as those with multiple sclerosis, muscle dystrophy, or spinal cord injuries, by developing a flexible hardware and software solution. This paper presents the research and development efforts of our team, which commenced in 2019 and is now in its final stage. Recognizing the diverse needs and limitations of individuals with limited mobility, we conducted in-depth testing with a group of 30 participants. The insights gained from these tests led to the complete redesign of the system. Our presentation covers the initial project ideas, observations from in-situ tests, and the newly developed system that is currently under construction. Moreover, in response to the financial constraints faced by many disabled individuals, we propose an affordable business model for the future commercialization of our invention. Through the Paulina Project, we strive to empower immobilized individuals, providing them with greater independence and improved quality of life.Keywords: UI, human-machine interface, social inclusion, multiple sclerosis, muscular dystrophy, spinal cord injury, quadriplegic
Procedia PDF Downloads 63607 Wave Propagation In Functionally Graded Lattice Structures Under Impact Loads
Authors: Mahmood Heshmati, Farhang Daneshmand
Abstract:
Material scientists and engineers have introduced novel materials with complex geometries due to the recent technological advances and promotion of manufacturing methods. Among them, lattice structures with graded architectures denoted by functionally graded porous materials (FGPMs) have been developed to optimize the structural response. FGPMs are achieved by tailoring the size and density of the internal pores in one or more directions that lead to the desired mechanical properties and structural responses. Also, FGPMs provide more flexible transition and the possibility of designing and fabricating structural elements with complex and variable properties. In this paper, wave propagation in lattice structures with functionally graded (FG) porosity is investigated in order to examine the ability of shock absorbing effect. The behavior of FG porous beams with different porosity distributions under impact load and the effects of porosity distribution and porosity content on the wave speed are studied. Important conclusions are made, along with a discussion of the future scope of studies on FGPMs structures.Keywords: functionally graded, porous materials, wave propagation, impact load, finite element
Procedia PDF Downloads 76606 Study on Multi-Point Stretch Forming Process for Double Curved Surface
Authors: Jiwoo Park, Junseok Yoon, Jeong Kim, Beomsoo Kang
Abstract:
Multi-Point Stretch Forming (MPSF) process is suitable for flexible manufacturing, and it has several advantages including that it could be applied to various forming such as sheet metal forming, single curved surface forming and double curved one. In this study, a systematic numerical simulation was carried out for atypical double curved surface forming using the multiple die stretch forming process. In this simulation, urethane pads were defined based on hyper-elastic material model as a cushion for the smooth forming surface. The deformation behaviour on elastic recovery was also investigated to consider the exact result after the last forming process, and then the experiment was also carried out to confirm the formability of this forming process. By comparing the simulation and experiment results, the suitability of the multiple die stretch forming process for the atypical double curved surface was verified. Consequently, it is confirmed that the multi-point stretch forming process has the capability and feasibility of being used to manufacture the double curved surfaces of sheet metal.Keywords: multi-point stretch forming, double curved surface, numerical simulation, manufacturing
Procedia PDF Downloads 472605 Learning to Teach on the Cloud: Preservice EFL Teachers’ Online Project-Based Practicum Experience
Authors: Mei-Hui Liu
Abstract:
This paper reports 20 preservice EFL teachers’ learning-to-teach experience when they were engaged in an online project-based practicum implemented on a Cloud Platform. This 10-month study filled in the literature gap by documenting the impact of online project-based instruction on preservice EFL teachers’ professional development. Data analysis showed that the online practicum was regarded as a flexible mechanism offering chances of teaching practices without geographical barriers. Additionally, this project-based practice helped the participants integrate the theories they had learned and further foster them how to create a self-directed online learning environment. Furthermore, these preservice teachers with experiences of technology-enabled practicum showed their motivation to apply technology and online platforms into future instructional practices. Yet, this study uncovered several concerns encountered by these participants during this online field experience. The findings of this study rendered meaning and lessons for teacher educators intending to integrate online practicum into preservice training courses.Keywords: online teaching practicum, project-based learning, teacher preparation, English language education
Procedia PDF Downloads 363604 Development and Characterisation of a Microbioreactor 'Cassette' for Cell Culture Applications
Authors: Nelson Barrientos, Matthew J. Davies, Marco C. Marques, Darren N. Nesbeth, Gary J. Lye, Nicolas Szita
Abstract:
Microbioreactor technology is making important advances towards its application in cell culture and bioprocess development. In particular, the technology promises flexible and controllable devices capable to perform parallelised experimentation at low cost. Currently, state of the art methods (e.g. optical sensors) allow the accurate monitoring of the microbioreactor operation. In addition, the laminar flow regime encountered in these devices allows more predictive fluid dynamics modelling, improving the control over the soluble, physical and mechanical environment of the cells. This work describes the development and characterisation of a novel microbioreactor cassette system (microbioreactor volume is 150 μL. The volumetric oxygen transfer coefficient (KLa) and mixing time have been characterised to be between 25 to 113 h-1 and 0.5 and 0.1 s, respectively. In addition, the Residence time distribution (RTD) analysis confirms that the reactor operates at well mixed conditions. Finally, Staphylococcus carnosus TM300 growth is demonstrated via batch culture experiments. Future work consists in expanding the optics of the microbioreactor design to include the monitoring of variables such as fluorescent protein expression, among others.Keywords: microbioreactor, cell-culture, fermentation, microfluidics
Procedia PDF Downloads 399603 Wireless Transmission of Big Data Using Novel Secure Algorithm
Authors: K. Thiagarajan, K. Saranya, A. Veeraiah, B. Sudha
Abstract:
This paper presents a novel algorithm for secure, reliable and flexible transmission of big data in two hop wireless networks using cooperative jamming scheme. Two hop wireless networks consist of source, relay and destination nodes. Big data has to transmit from source to relay and from relay to destination by deploying security in physical layer. Cooperative jamming scheme determines transmission of big data in more secure manner by protecting it from eavesdroppers and malicious nodes of unknown location. The novel algorithm that ensures secure and energy balance transmission of big data, includes selection of data transmitting region, segmenting the selected region, determining probability ratio for each node (capture node, non-capture and eavesdropper node) in every segment, evaluating the probability using binary based evaluation. If it is secure transmission resume with the two- hop transmission of big data, otherwise prevent the attackers by cooperative jamming scheme and transmit the data in two-hop transmission.Keywords: big data, two-hop transmission, physical layer wireless security, cooperative jamming, energy balance
Procedia PDF Downloads 480602 Integrated Vegetable Production Planning Considering Crop Rotation Rules Using a Mathematical Mixed Integer Programming Model
Authors: Mohammadali Abedini Sanigy, Jiangang Fei
Abstract:
In this paper, a mathematical optimization model was developed to maximize the profit in a vegetable production planning problem. It serves as a decision support system that assists farmers in land allocation to crops and harvest scheduling decisions. The developed model can handle different rotation rules in two consecutive cycles of production, which is a common practice in organic production system. Moreover, different production methods of the same crop were considered in the model formulation. The main strength of the model is that it is not restricted to predetermined production periods, which makes the planning more flexible. The model is classified as a mixed integer programming (MIP) model and formulated in PYOMO -a Python package to formulate optimization models- and solved via Gurobi and CPLEX optimizer packages. The model was tested with secondary data from 'Australian vegetable growing farms', and the results were obtained and discussed with the computational test runs. The results show that the model can successfully provide reliable solutions for real size problems.Keywords: crop rotation, harvesting, mathematical model formulation, vegetable production
Procedia PDF Downloads 179601 A Novel Software Model for Enhancement of System Performance and Security through an Optimal Placement of PMU and FACTS
Authors: R. Kiran, B. R. Lakshmikantha, R. V. Parimala
Abstract:
Secure operation of power systems requires monitoring of the system operating conditions. Phasor measurement units (PMU) are the device, which uses synchronized signals from the GPS satellites, and provide the phasors information of voltage and currents at a given substation. The optimal locations for the PMUs must be determined, in order to avoid redundant use of PMUs. The objective of this paper is to make system observable by using minimum number of PMUs & the implementation of stability software at 22OkV grid for on-line estimation of the power system transfer capability based on voltage and thermal limitations and for security monitoring. This software utilizes State Estimator (SE) and synchrophasor PMU data sets for determining the power system operational margin under normal and contingency conditions. This software improves security of transmission system by continuously monitoring operational margin expressed in MW or in bus voltage angles, and alarms the operator if the margin violates a pre-defined threshold.Keywords: state estimator (SE), flexible ac transmission systems (FACTS), optimal location, phasor measurement units (PMU)
Procedia PDF Downloads 402600 Investigation of a Hybrid Process: Multipoint Incremental Forming
Authors: Safa Boudhaouia, Mohamed Amen Gahbiche, Eliane Giraud, Wacef Ben Salem, Philippe Dal Santo
Abstract:
Multi-point forming (MPF) and asymmetric incremental forming (ISF) are two flexible processes for sheet metal manufacturing. To take advantages of these two techniques, a hybrid process has been developed: The Multipoint Incremental Forming (MPIF). This process accumulates at once the advantages of each of these last mentioned forming techniques, which makes it a very interesting and particularly an efficient process for single, small, and medium series production. In this paper, an experimental and a numerical investigation of this technique are presented. To highlight the flexibility of this process and its capacity to manufacture standard and complex shapes, several pieces were produced by using MPIF. The forming experiments are performed on a 3-axis CNC machine. Moreover, a numerical model of the MPIF process has been implemented in ABAQUS and the analysis showed a good agreement with experimental results in terms of deformed shape. Furthermore, the use of an elastomeric interpolator allows avoiding classical local defaults like dimples, which are generally caused by the asymmetric contact and also improves the distribution of residual strain. Future works will apply this approach to other alloys used in aeronautic or automotive applications.Keywords: incremental forming, numerical simulation, MPIF, multipoint forming
Procedia PDF Downloads 349599 The Role of Community Activism in Promoting Social Justice around Housing Issues: A Case Study of the Western Cape
Authors: Mapule Maema
Abstract:
The paper aims to highlight the role that community activism has played in promoting social justice around housing issues in the Western Cape. The Western Cape is one of the largest spatially segregated provinces in South Africa which continues to exhibit grave inequalities between cities, townships and farms. These inequalities cut across intersectional issues such as, race, class, gender, and politics. The main challenges facing marginalized communities in the Western Cape include access to housing, land and basic services. This is not peculiar to only the Western Cape, the entire country is facing similar challenges however the Western Cape is seen as a fasted urbanizing province in the country due to tourism. Various social movements have been formed across the country to counter these challenges, however, this paper focuses on the resilience communities have fostered despite the myriad housing and spatial crisis they are faced with. The paper focuses on the Legal Resource’s Centre’s clients from an informal settlement called Imizamo Yethu based in Hout Bay Valley area. The 18 hectare settlement houses approximately 33600 people. On the 21st July 2017, Hout Bay experienced violent protests following an eviction order passed by the City of Cape Town. The protest was characterized by tensions within the community regarding the super-blocking initiative which aims to establish roads in informal settlements to ensure basic services. Residents against the process argued that there were no proper consultations done to educate them on what this process entailed. Public participation is one of the objectives the municipalities aim to promote however it remains a great challenge. In order to highlight the experiences of the LRC clients in relation to what motivated their involvement in the movement, how it felt their participation, and aspirations, the paper will employ qualitative research methods. Qualitative research methods enable the researcher to get a deeper and nuanced understanding of the social world in the eyes of those who experienced it. It is a flexible methodology that enables one to also understand social processes and the significance they generate. Data will be collected through the use of the World Cafe as a focus group method. The World Café is a simple, effective and flexible format for hosting group dialogue. The steps taken when setting up a World Café includes the following: setting the context (why you are bringing people together and what you want to achieve), create hospitality space (make participants feel at home and free to discuss issues), explore questions that matter, connect diverse perspectives (the opportunity to actively contribute your thinking), listen together for patterns and insights, share collective discoveries and learnings. Secondary data will be used to augment the data collected. Stories of impact will be drawn from the exercises. This paper will contribute to the discourse of sustainable housing and urban development and the research outputs will be disseminated to the public for learning.Keywords: community activism, influence, social justice, development
Procedia PDF Downloads 126