Search results for: conceptual domain of law
990 Defining a Reference Architecture for Predictive Maintenance Systems: A Case Study Using the Microsoft Azure IoT-Cloud Components
Authors: Walter Bernhofer, Peter Haber, Tobias Mayer, Manfred Mayr, Markus Ziegler
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Current preventive maintenance measures are cost intensive and not efficient. With the available sensor data of state of the art internet of things devices new possibilities of automated data processing emerge. Current advances in data science and in machine learning enable new, so called predictive maintenance technologies, which empower data scientists to forecast possible system failures. The goal of this approach is to cut expenses in preventive maintenance by automating the detection of possible failures and to improve efficiency and quality of maintenance measures. Additionally, a centralization of the sensor data monitoring can be achieved by using this approach. This paper describes the approach of three students to define a reference architecture for a predictive maintenance solution in the internet of things domain with a connected smartphone app for service technicians. The reference architecture is validated by a case study. The case study is implemented with current Microsoft Azure cloud technologies. The results of the case study show that the reference architecture is valid and can be used to achieve a system for predictive maintenance execution with the cloud components of Microsoft Azure. The used concepts are technology platform agnostic and can be reused in many different cloud platforms. The reference architecture is valid and can be used in many use cases, like gas station maintenance, elevator maintenance and many more.Keywords: case study, internet of things, predictive maintenance, reference architecture
Procedia PDF Downloads 252989 Nondestructive Evaluation of Hidden Delamination in Glass Fiber Composite Using Terahertz Spectroscopy
Authors: Chung-Hyeon Ryu, Do-Hyoung Kim, Hak-Sung Kim
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As the use of the composites was increased, the detecting method of hidden damages which have an effect on performance of the composite was important. Terahertz (THz) spectroscopy was assessed as one of the new powerful nondestructive evaluation (NDE) techniques for fiber reinforced composite structures because it has many advantages which can overcome the limitations of conventional NDE techniques such as x-rays or ultrasound. The THz wave offers noninvasive, noncontact and nonionizing methods evaluating composite damages, also it gives a broad range of information about the material properties. In additions, it enables to detect the multiple-delaminations of various nonmetallic materials. In this study, the pulse type THz spectroscopy imaging system was devised and used for detecting and evaluating the hidden delamination in the glass fiber reinforced plastic (GFRP) composite laminates. The interaction between THz and the GFRP composite was analyzed respect to the type of delamination, including their thickness, size and numbers of overlaps among multiple-delaminations in through-thickness direction. Both of transmission and reflection configurations were used for evaluation of hidden delaminations and THz wave propagations through the delaminations were also discussed. From these results, various hidden delaminations inside of the GFRP composite were successfully detected using time-domain THz spectroscopy imaging system and also compared to the results of C-scan inspection. It is expected that THz NDE technique will be widely used to evaluate the reliability of composite structures.Keywords: terahertz, delamination, glass fiber reinforced plastic composites, terahertz spectroscopy
Procedia PDF Downloads 592988 Review on the Role of Sustainability Techniques in Development of Green Building
Authors: Ubaid Ur Rahman, Waqar Younas, Sooraj Kumar Chhabira
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Environmentally sustainable building construction has experienced significant growth during the past 10 years at international level. This paper shows that the conceptual framework adopts sustainability techniques in construction to develop environment friendly building called green building. Waste occurs during the different construction phases which causes the environmental problems like, deposition of waste on ground surface creates major problems such as bad smell. It also gives birth to different health diseases and produces toxic waste agent which is specifically responsible for making soil infertile. Old recycled building material is used in the construction of new building. Sustainable construction is economical and saves energy sources. Sustainable construction is the major responsibility of designer and project manager. The designer has to fulfil the client demands while keeping the design environment friendly. Project manager has to deliver and execute sustainable construction according to sustainable design. Steel is the most appropriate sustainable construction material. It is more durable and easily recyclable. Steel occupies less area and has more tensile and compressive strength than concrete, making it a better option for sustainable construction as compared to other building materials. New technology like green roof has made the environment pleasant, and has reduced the construction cost. It minimizes economic, social and environmental issues. This paper presents an overview of research related to the material use of green building and by using this research recommendation are made which can be followed in the construction industry. In this paper, we go through detailed analysis on construction material. By making suitable adjustments to project management practices it is shown that a green building improves the cost efficiency of the project, makes it environmental friendly and also meets future generation demands.Keywords: sustainable construction, green building, recycled waste material, environment
Procedia PDF Downloads 245987 A Study of Electric Generation Characteristics for Thin-Film Piezoelectric PbZrTiO₃ Ceramic Plate during the Static and Cyclic Loading Conditions
Authors: Tsukasa Ogawa, Mitsuhiro Okayasu
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To examine the generation properties of electric power for piezoelectric (PbZrTiO3) ceramic plates, the electric-power generation characteristics were examined experimentally and numerically during cyclic bending under various loading fixtures with different contact condition, i.e., point and area contact. In the low applied loading condition between 10 and 50 N, increasing the load-contact area on the piezoelectric ceramic led to a nonlinear decrease in the generated voltage. Decreasing contact area, including the point contact, basically enhanced the generated voltage, although the voltage saturated during loading when the contact area is less than ϕ5 mm, which was attributed to the high strain status, resulting in the material failure, i.e., high stress concentration. In this case, severe plastic deformation and the domain switching were dominated failure modes in the ceramic. From this approach, it is clear that the applied load became more larger (50 ~100 N), larger contact area (ϕ10 ~ ϕ20 mm) became advantageous for power generation. Based upon this cyclic loading was carried out to investigate the fatigue characteristics of the piezoelectric ceramic late. For all contact conditions, electric voltage dropped in the beginning of the cyclic loading, although the higher electric generation was stable in the further cyclic loading for the contact area of ϕ10 ~ ϕ20 mm. In constant, further decrement of electric generation occurred for the point contact condition, and the low electric voltage was generated for the larger contact condition.Keywords: electric power generation, piezoelectric ceramic, lead zirconate titanate ceramic, loading conditions
Procedia PDF Downloads 168986 Numerical Simulation of Two-Dimensional Flow over a Stationary Circular Cylinder Using Feedback Forcing Scheme Based Immersed Boundary Finite Volume Method
Authors: Ranjith Maniyeri, Ahamed C. Saleel
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Two-dimensional fluid flow over a stationary circular cylinder is one of the bench mark problem in the field of fluid-structure interaction in computational fluid dynamics (CFD). Motivated by this, in the present work, a two-dimensional computational model is developed using an improved version of immersed boundary method which combines the feedback forcing scheme of the virtual boundary method with Peskin’s regularized delta function approach. Lagrangian coordinates are used to represent the cylinder and Eulerian coordinates are used to describe the fluid flow. A two-dimensional Dirac delta function is used to transfer the quantities between the sold to fluid domain. Further, continuity and momentum equations governing the fluid flow are solved using fractional step based finite volume method on a staggered Cartesian grid system. The developed code is validated by comparing the values of drag coefficient obtained for different Reynolds numbers with that of other researcher’s results. Also, through numerical simulations for different Reynolds numbers flow behavior is well captured. The stability analysis of the improved version of immersed boundary method is tested for different values of feedback forcing coefficients.Keywords: Feedback Forcing Scheme, Finite Volume Method, Immersed Boundary Method, Navier-Stokes Equations
Procedia PDF Downloads 305985 Effective Environmental Planning Management (EPM) as Panacea to Sustainable Urban Development
Authors: Jegede Kehinde Jacob, Ola Akeem Bayonle, Adewale Yemi Yekeen
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The rapid rate of urban growth in most developing countries of the world in recent times is alarming. Mass movement of people from rural areas to the urban centres, the consequence of the uncontrolled rapid urbanisation resulting to many un-conforming environmental challenges such as inadequate infrastructure, land, water and air pollution, poor environmental sanitation, poor and inadequate housing, urban degradation, sprawl and slums, urban violence, crime, robbery and prostitution as well as many other social vices that make the cities unsustainable. The resultant effects of all these are abysmal failure in the management of cities on the part of the governing authorities and other relevant stakeholders as well as unconducive and unwholesome condition of living of the people. This paper attempts to examine holistically the issue of environmental planning management (EPM) process development and management concept with a view for dynamic and interactive approach for various stakeholders as partners in achieving sustainable cities of our dream. The areas of discussion including conceptual and contextual issues, sustainable cities concept, good urban governance including literature review. The paper goes further to examine opportunities and challenges of built environment generally, the nature and context of environmental problems in particular, the role and duties of environmental planning and management (EPM) process in sustainable urban development. The paper further reviewed briefly the various levels of institutionalisation of EPM process with a typical case study of sustainable Ibadan project (SIP). The paper concludes with a list of recommendations to ensure effective and lasting solutions to cities problems through initiation of EPM process achievable in a sustainable manner.Keywords: built environment, environmental planning, sustainable cities, sustainable development, urbanization
Procedia PDF Downloads 264984 Probabilistic Approach of Dealing with Uncertainties in Distributed Constraint Optimization Problems and Situation Awareness for Multi-agent Systems
Authors: Sagir M. Yusuf, Chris Baber
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In this paper, we describe how Bayesian inferential reasoning will contributes in obtaining a well-satisfied prediction for Distributed Constraint Optimization Problems (DCOPs) with uncertainties. We also demonstrate how DCOPs could be merged to multi-agent knowledge understand and prediction (i.e. Situation Awareness). The DCOPs functions were merged with Bayesian Belief Network (BBN) in the form of situation, awareness, and utility nodes. We describe how the uncertainties can be represented to the BBN and make an effective prediction using the expectation-maximization algorithm or conjugate gradient descent algorithm. The idea of variable prediction using Bayesian inference may reduce the number of variables in agents’ sampling domain and also allow missing variables estimations. Experiment results proved that the BBN perform compelling predictions with samples containing uncertainties than the perfect samples. That is, Bayesian inference can help in handling uncertainties and dynamism of DCOPs, which is the current issue in the DCOPs community. We show how Bayesian inference could be formalized with Distributed Situation Awareness (DSA) using uncertain and missing agents’ data. The whole framework was tested on multi-UAV mission for forest fire searching. Future work focuses on augmenting existing architecture to deal with dynamic DCOPs algorithms and multi-agent information merging.Keywords: DCOP, multi-agent reasoning, Bayesian reasoning, swarm intelligence
Procedia PDF Downloads 119983 Reliability and Construct Validity of the Early Dementia Questionnaire (EDQ)
Authors: A. Zurraini, Syed Alwi Sar, H. Helmy, H. Nazeefah
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Early Dementia Questionnaire (EDQ) was developed as a screening tool to detect patients with early dementia in primary care. It was developed based on 20 symptoms of dementia. From a preliminary study, EDQ had been shown to be a promising alternative for screening of early dementia. This study was done to further test on EDQ’s reliability and validity. Using a systematic random sampling, 200 elderly patients attending primary health care centers in Kuching, Sarawak had consented to participate in the study and were administered the EDQ. Geriatric Depression Scale (GDS) was used to exclude patients with depression. Those who scored >21 MMSE, were retested using the EDQ. Reliability was determined by Cronbach’s alpha for internal consistency and construct validity was assessed using confirmatory factor analysis (principle component with varimax rotation). The result showed that the overall Cronbach’s alpha coefficient was good which was 0.874. Confirmatory factor analysis on 4 factors indicated that the Cronbach’s alpha for each domain were acceptable with memory (0.741), concentration (0.764), emotional and physical symptoms (0.754) and lastly sleep and environment (0.720). Pearson correlation coefficient between the first EDQ score and the retest EDQ score among those with MMSE of >21 showed a very strong, positive correlation between the two variables, r = 0.992, N=160, P <0.001. The results of the validation study showed that Early Dementia Questionnaire (EDQ) is a valid and reliable tool to be used as a screening tool to detect early dementia in primary care.Keywords: Early Dementia Questionnaire (EDQ), screening, primary care, construct validity
Procedia PDF Downloads 436982 A Survey of Feature-Based Steganalysis for JPEG Images
Authors: Syeda Mainaaz Unnisa, Deepa Suresh
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Due to the increase in usage of public domain channels, such as the internet, and communication technology, there is a concern about the protection of intellectual property and security threats. This interest has led to growth in researching and implementing techniques for information hiding. Steganography is the art and science of hiding information in a private manner such that its existence cannot be recognized. Communication using steganographic techniques makes not only the secret message but also the presence of hidden communication, invisible. Steganalysis is the art of detecting the presence of this hidden communication. Parallel to steganography, steganalysis is also gaining prominence, since the detection of hidden messages can prevent catastrophic security incidents from occurring. Steganalysis can also be incredibly helpful in identifying and revealing holes with the current steganographic techniques, which makes them vulnerable to attacks. Through the formulation of new effective steganalysis methods, further research to improve the resistance of tested steganography techniques can be developed. Feature-based steganalysis method for JPEG images calculates the features of an image using the L1 norm of the difference between a stego image and the calibrated version of the image. This calibration can help retrieve some of the parameters of the cover image, revealing the variations between the cover and stego image and enabling a more accurate detection. Applying this method to various steganographic schemes, experimental results were compared and evaluated to derive conclusions and principles for more protected JPEG steganography.Keywords: cover image, feature-based steganalysis, information hiding, steganalysis, steganography
Procedia PDF Downloads 216981 Physics-Informed Machine Learning for Displacement Estimation in Solid Mechanics Problem
Authors: Feng Yang
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Machine learning (ML), especially deep learning (DL), has been extensively applied to many applications in recently years and gained great success in solving different problems, including scientific problems. However, conventional ML/DL methodologies are purely data-driven which have the limitations, such as need of ample amount of labelled training data, lack of consistency to physical principles, and lack of generalizability to new problems/domains. Recently, there is a growing consensus that ML models need to further take advantage of prior knowledge to deal with these limitations. Physics-informed machine learning, aiming at integration of physics/domain knowledge into ML, has been recognized as an emerging area of research, especially in the recent 2 to 3 years. In this work, physics-informed ML, specifically physics-informed neural network (NN), is employed and implemented to estimate the displacements at x, y, z directions in a solid mechanics problem that is controlled by equilibrium equations with boundary conditions. By incorporating the physics (i.e. the equilibrium equations) into the learning process of NN, it is showed that the NN can be trained very efficiently with a small set of labelled training data. Experiments with different settings of the NN model and the amount of labelled training data were conducted, and the results show that very high accuracy can be achieved in fulfilling the equilibrium equations as well as in predicting the displacements, e.g. in setting the overall displacement of 0.1, a root mean square error (RMSE) of 2.09 × 10−4 was achieved.Keywords: deep learning, neural network, physics-informed machine learning, solid mechanics
Procedia PDF Downloads 150980 Performing Diagnosis in Building with Partially Valid Heterogeneous Tests
Authors: Houda Najeh, Mahendra Pratap Singh, Stéphane Ploix, Antoine Caucheteux, Karim Chabir, Mohamed Naceur Abdelkrim
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Building system is highly vulnerable to different kinds of faults and human misbehaviors. Energy efficiency and user comfort are directly targeted due to abnormalities in building operation. The available fault diagnosis tools and methodologies particularly rely on rules or pure model-based approaches. It is assumed that model or rule-based test could be applied to any situation without taking into account actual testing contexts. Contextual tests with validity domain could reduce a lot of the design of detection tests. The main objective of this paper is to consider fault validity when validate the test model considering the non-modeled events such as occupancy, weather conditions, door and window openings and the integration of the knowledge of the expert on the state of the system. The concept of heterogeneous tests is combined with test validity to generate fault diagnoses. A combination of rules, range and model-based tests known as heterogeneous tests are proposed to reduce the modeling complexity. Calculation of logical diagnoses coming from artificial intelligence provides a global explanation consistent with the test result. An application example shows the efficiency of the proposed technique: an office setting at Grenoble Institute of Technology.Keywords: heterogeneous tests, validity, building system, sensor grids, sensor fault, diagnosis, fault detection and isolation
Procedia PDF Downloads 294979 Artificial Intelligence-Based Thermal Management of Battery System for Electric Vehicles
Authors: Raghunandan Gurumurthy, Aricson Pereira, Sandeep Patil
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The escalating adoption of electric vehicles (EVs) across the globe has underscored the critical importance of advancing battery system technologies. This has catalyzed a shift towards the design and development of battery systems that not only exhibit higher energy efficiency but also boast enhanced thermal performance and sophisticated multi-material enclosures. A significant leap in this domain has been the incorporation of simulation-based design optimization for battery packs and Battery Management Systems (BMS), a move further enriched by integrating artificial intelligence/machine learning (AI/ML) approaches. These strategies are pivotal in refining the design, manufacturing, and operational processes for electric vehicles and energy storage systems. By leveraging AI/ML, stakeholders can now predict battery performance metrics—such as State of Health, State of Charge, and State of Power—with unprecedented accuracy. Furthermore, as Li-ion batteries (LIBs) become more prevalent in urban settings, the imperative for bolstering thermal and fire resilience has intensified. This has propelled Battery Thermal Management Systems (BTMs) to the forefront of energy storage research, highlighting the role of machine learning and AI not just as tools for enhanced safety management through accurate temperature forecasts and diagnostics but also as indispensable allies in the early detection and warning of potential battery fires.Keywords: electric vehicles, battery thermal management, industrial engineering, machine learning, artificial intelligence, manufacturing
Procedia PDF Downloads 97978 Spatial Indeterminacy: Destabilization of Dichotomies in Modern and Contemporary Architecture
Authors: Adrian Lo
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Since the beginning of modern architecture, ideas of free plan and transparency have proliferated well into current trends of building design, from houses to highrise office buildings. The movement’s notion of a spatially homogeneous, open, and limitless ‘free plan’ stands opposite to the spatially heterogeneous ‘separation of rooms’ defined by load-bearing walls, which in turn triggered new notions of transparency achieved by vast expanses of glazed walls. Similarly, transparency was also dichotomized as something that was physical or optical, as well as something conceptual, akin to spatial organization. As opposed to merely accepting the duality and possible incompatibility of these dichotomies, this paper seeks to ask how can space be both literally and phenomenally transparent, as well as display both homogeneous and heterogeneous qualities? This paper explores this potential destabilization or blurring of spatial phenomena by dissecting the transparent layers and volumes of a series of selected case studies to investigate how different architects have devised strategies of spatial ambivalence, ambiguity, and interpenetration. Projects by Peter Eisenman, Sou Fujimoto, and SANAA will be discussed and analyzed to show how the superimposition of geometries and spaces achieve different conditions of layering, transparency, and interstitiality. Their particular buildings will be explored to reveal various innovative kinds of spatial interpenetration produced through the articulate relations of the elements of architecture, which challenge conventional perceptions of interior and exterior whereby visual homogeneity blurs with spatial heterogeneity. The results show how spatial conceptions such as interpenetration and transparency have the ability to subvert not only inside-outside dialectics but could also produce multiple degrees of interiority within complex and indeterminate spatial dimensions in constant flux as well as present alternative forms of social interaction.Keywords: interpenetration, literal and phenomenal transparency, spatial heterogeneity, visual homogeneity
Procedia PDF Downloads 177977 A Uniformly Convergent Numerical Scheme for a Singularly Perturbed Volterra Integrodifferential Equation
Authors: Nana Adjoah Mbroh, Suares Clovis Oukouomi Noutchie
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Singularly perturbed problems are parameter dependent problems, and they play major roles in the modelling of real-life situational problems in applied sciences. Thus, designing efficient numerical schemes to solve these problems is of much interest since the exact solutions of such problems may not even exist. Generally, singularly perturbed problems are identified by a small parameter multiplying at least the highest derivative in the equation. The presence of this parameter causes the solution of these problems to be characterized by rapid oscillations. This unique feature renders classical numerical schemes inefficient since they are unable to capture the behaviour of the exact solution in the part of the domain where the rapid oscillations are present. In this paper, a numerical scheme is proposed to solve a singularly perturbed Volterra Integro-differential equation. The scheme is based on the midpoint rule and employs the non-standard finite difference scheme to solve the differential part whilst the composite trapezoidal rule is used for the integral part. A fully fledged error estimate is performed, and Richardson extrapolation is applied to accelerate the convergence of the scheme. Numerical simulations are conducted to confirm the theoretical findings before and after extrapolation.Keywords: midpoint rule, non-standard finite difference schemes, Richardson extrapolation, singularly perturbed problems, trapezoidal rule, uniform convergence
Procedia PDF Downloads 125976 Future Design and Innovative Economic Models for Futuristic Markets in Developing Countries
Authors: Nessreen Y. Ibrahim
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Designing the future according to realistic analytical study for the futuristic market needs can be a milestone strategy to make a huge improvement in developing countries economics. In developing countries, access to high technology and latest science approaches is very limited. The financial problems in low and medium income countries have negative effects on the kind and quality of imported new technologies and application for their markets. Thus, there is a strong need for shifting paradigm thinking in the design process to improve and evolve their development strategy. This paper discusses future possibilities in developing countries, and how they can design their own future according to specific future models FDM (Future Design Models), which established to solve certain economical problems, as well as political and cultural conflicts. FDM is strategic thinking framework provides an improvement in both content and process. The content includes; beliefs, values, mission, purpose, conceptual frameworks, research, and practice, while the process includes; design methodology, design systems, and design managements tools. In this paper the main objective was building an innovative economic model to design a chosen possible futuristic scenario; by understanding the market future needs, analyze real world setting, solve the model questions by future driven design, and finally interpret the results, to discuss to what extent the results can be transferred to the real world. The paper discusses Egypt as a potential case study. Since, Egypt has highly complex economical problems, extra-dynamic political factors, and very rich cultural aspects; we considered Egypt is a very challenging example for applying FDM. The paper results recommended using FDM numerical modeling as a starting point to design the future.Keywords: developing countries, economic models, future design, possible futures
Procedia PDF Downloads 267975 Gamipulation: Exploring Covert Manipulation through Gamification in the Context of Education
Authors: Aguiar-Castillo Lidia, Perez-Jimenez Rafael
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The integration of gamification in educational settings aims to enhance student engagement and motivation through game design elements in learning activities. This paper introduces "Gamipulation," the subtle manipulation of students via gamification techniques serving hidden agendas without explicit consent. It highlights the need to distinguish between beneficial and exploitative uses of gamification in education, focusing on its potential to psychologically manipulate students for purposes misaligned with their best interests. Through a literature review and expert interviews, this study presents a conceptual framework outlining gamipulation's features. It examines ethical concerns like gradually introducing desired behaviors, using distraction to divert attention from significant learning objectives, immediacy of rewards fostering short-term engagement over long-term learning, infantilization of students, and exploitation of emotional responses over reflective thinking. Additionally, it discusses ethical issues in collecting and utilizing student data within gamified environments. Key findings suggest that while gamification can enhance motivation and engagement, there's a fine line between ethical motivation and unethical manipulation. The study emphasizes the importance of transparency, respect for student autonomy, and alignment with educational values in gamified systems. It calls for educators and designers to be aware of gamification's manipulative potential and strive for ethical implementation that benefits students. In conclusion, this paper provides a framework for educators and researchers to understand and address gamipulation's ethical challenges. It encourages developing ethical guidelines and practices to ensure gamification in education remains a tool for positive engagement and learning rather than covert manipulation.Keywords: gradualness, distraction, immediacy, infantilization, emotion
Procedia PDF Downloads 27974 Macular Ganglion Cell Inner Plexiform Layer Thinning
Authors: Hye-Young Shin, Chan Kee Park
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Background: To compare the thinning patterns of the ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (pRNFL) as measured using Cirrus high-definition optical coherence tomography (HD-OCT) in patients with visual field (VF) defects that respect the vertical meridian. Methods: Twenty eyes of eleven patients with VF defects that respect the vertical meridian were enrolled retrospectively. The thicknesses of the macular GCIPL and pRNFL were measured using Cirrus HD-OCT. The 5% and 1% thinning area index (TAI) was calculated as the proportion of abnormally thin sectors at the 5% and 1% probability level within the area corresponding to the affected VF. The 5% and 1% TAI were compared between the GCIPL and pRNFL measurements. Results: The color-coded GCIPL deviation map showed a characteristic vertical thinning pattern of the GCIPL, which is also seen in the VF of patients with brain lesions. The 5% and 1% TAI were significantly higher in the GCIPL measurements than in the pRNFL measurements (all P < 0.01). Conclusions: Macular GCIPL analysis clearly visualized a characteristic topographic pattern of retinal ganglion cell (RGC) loss in patients with VF defects that respect the vertical meridian, unlike pRNFL measurements. Macular GCIPL measurements provide more valuable information than pRNFL measurements for detecting the loss of RGCs in patients with retrograde degeneration of the optic nerve fibers.Keywords: brain lesion, macular ganglion cell, inner plexiform layer, spectral-domain optical coherence tomography
Procedia PDF Downloads 337973 Continuous-Time Analysis And Performance Assessment For Digital Control Of High-Frequency Switching Synchronous Dc-Dc Converter
Authors: Rihab Hamdi, Amel Hadri Hamida, Ouafae Bennis, Sakina Zerouali
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This paper features a performance analysis and robustness assessment of a digitally controlled DC-DC three-cell buck converter associated in parallel, operating in continuous conduction mode (CCM), facing feeding parameters variation and loads disturbance. The control strategy relies on the continuous-time with an averaged modeling technique for high-frequency switching converter. The methodology is to modulate the complete design procedure, in regard to the existence of an instantaneous current operating point for designing the digital closed-loop, to the same continuous-time domain. Moreover, the adopted approach is to include a digital voltage control (DVC) technique, taking an account for digital control delays and sampling effects, which aims at improving efficiency and dynamic response and preventing generally undesired phenomena. The results obtained under load change, input change, and reference change clearly demonstrates an excellent dynamic response of the proposed technique, also as provide stability in any operating conditions, the effectiveness is fast with a smooth tracking of the specified output voltage. Simulations studies in MATLAB/Simulink environment are performed to verify the concept.Keywords: continuous conduction mode, digital control, parallel multi-cells converter, performance analysis, power electronics
Procedia PDF Downloads 150972 Bacterial Cellulose/Silver-Doped Hydroxyapatite Composites for Tissue Engineering Application
Authors: Adrian Ionut Nicoara, Denisa Ionela Ene, Alina Maria Holban, Cristina Busuioc
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At present, the development of materials with biomedical applications is a domain of interest that will produce a full series of benefits in engineering and medicine. In this sense, it is required to use a natural material, and this paper is focused on the development of a composite material based on bacterial cellulose – hydroxyapatite and silver nanoparticles with applications in hard tissue. Bacterial cellulose own features like biocompatibility, non-toxicity character and flexibility. Moreover, the bacterial cellulose can be conjugated with different forms of active silver to possess antimicrobial activity. Hydroxyapatite is well known that can mimic at a significant level the activity of the initial bone. The material was synthesized by using an ultrasound probe and finally characterized by several methods. Thereby, the morphological properties were analyzed by using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Because the synthesized material has medical application in restore the tissue and to fight against microbial invasion, the samples were tested from the biological point of view by evaluating the biodegradability in phosphate-buffered saline (PBS) and simulated body fluid (SBF) and moreover the antimicrobial effect was performed on Gram-positive bacterium Staphylococcus aureus, Gram-negative bacterium Escherichia coli, and fungi Candida albicans. The results reveal that the obtained material has specific characteristics for bone regeneration.Keywords: bacterial cellulose, biomaterials, hydroxyapatite, scaffolds materials
Procedia PDF Downloads 133971 Stochastic Edge Based Anomaly Detection for Supervisory Control and Data Acquisitions Systems: Considering the Zambian Power Grid
Authors: Lukumba Phiri, Simon Tembo, Kumbuso Joshua Nyoni
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In Zambia recent initiatives by various power operators like ZESCO, CEC, and consumers like the mines to upgrade power systems into smart grids target an even tighter integration with information technologies to enable the integration of renewable energy sources, local and bulk generation, and demand response. Thus, for the reliable operation of smart grids, its information infrastructure must be secure and reliable in the face of both failures and cyberattacks. Due to the nature of the systems, ICS/SCADA cybersecurity and governance face additional challenges compared to the corporate networks, and critical systems may be left exposed. There exist control frameworks internationally such as the NIST framework, however, there are generic and do not meet the domain-specific needs of the SCADA systems. Zambia is also lagging in cybersecurity awareness and adoption, therefore there is a concern about securing ICS controlling key infrastructure critical to the Zambian economy as there are few known facts about the true posture. In this paper, we introduce a stochastic Edged-based Anomaly Detection for SCADA systems (SEADS) framework for threat modeling and risk assessment. SEADS enables the calculation of steady-steady probabilities that are further applied to establish metrics like system availability, maintainability, and reliability.Keywords: anomaly, availability, detection, edge, maintainability, reliability, stochastic
Procedia PDF Downloads 110970 Teaching, Learning and Evaluation Enhancement of Information Communication Technology Education in Schools through Pedagogical and E-Learning Techniques in the Sri Lankan Context
Authors: M. G. N. A. S. Fernando
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This study uses a researchable framework to improve the quality of ICT education and the Teaching Learning Assessment/ Evaluation (TLA/TLE) process. It utilizes existing resources while improving the methodologies along with pedagogical techniques and e-Learning approaches used in the secondary schools of Sri Lanka. The study was carried out in two phases. Phase I focused on investigating the factors which affect the quality of ICT education. Based on the key factors of phase I, the Phase II focused on the design of an Experimental Application Model with 6 activity levels. Each Level in the Activity Model covers one or more levels in the Revised Bloom’s Taxonomy. Towards further enhancement of activity levels, other pedagogical techniques (activity based learning, e-learning techniques, problem solving activities and peer discussions etc.) were incorporated to each level in the activity model as appropriate. The application model was validated by a panel of teachers including a domain expert and was tested in the school environment too. The validity of performance was proved using 6 hypotheses testing and other methodologies. The analysis shows that student performance with problem solving activities increased by 19.5% due to the different treatment levels used. Compared to existing process it was also proved that the embedded techniques (mixture of traditional and modern pedagogical methods and their applications) are more effective with skills development of teachers and students.Keywords: activity models, Bloom’s taxonomy, ICT education, pedagogies
Procedia PDF Downloads 163969 Intuition in Negotiation within Ghanaian Social Contexts: Exploring Female Leadership Strategies for Conflict Transformation
Authors: Nadia Naadu Nartey, Esther A.O.G. Tetteh
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Male negotiator representations and the appreciation of masculine traits in negotiation contexts dominate negotiation research in the field of conflict management and resolution. This study switched focus to pay attention to rarely examined gendered criteria and social contexts in negotiation research by investigating how intuition has been used in negotiations by female leaders toward conflict transformation in Ghanaian social contexts. Using the theoretical lenses of Klein’s Recognition-Primed Decisions (RPD) and Unconscious Information Processing (UIP) models, this study employs narrative inquiry in qualitative research. Semi-structured interviews of five (5) female leaders of Ghanaian social contexts in the United States (US) revealed that the use of intuition is necessary for effective negotiation outcomes due to its primal focus on relationship-building toward transforming conflicts. The knowledge added to the body of research by this study is summed up in the study’s conceptual framework. Female leaders, in negotiation situations where there are conflicting parties, prioritize the greater need for stronger relationships and win-win outcomes. The participant female leaders in negotiation contexts utilize their intuition as a bonding mechanism by effectively timing their actions, using an appropriate communication tone, emphasizing relationship building, and drawing from experience to make sound situational judgments (as in assessing a situation in the RPD model). Female leaders’ use of intuition in negotiations then translates to creating a force that bridges the gap between the conflicting parties. That force is noticed as conflict transformation that manifests as a reduction in anger and a promotion of trust and mutual understanding toward strengthening relationships. Future studies can expand the scope of the findings of this research by conducting a comparative analysis between male and female leaders on their use of intuition in negotiations in Ghanaian contexts.Keywords: intuition, negotiation, conflict transformation, female leaders, ghanaian social contexts
Procedia PDF Downloads 12968 Zimbabwe's Foreign Policy in Southern Africa, 1980-2013
Authors: Dylan Yanano Mangani, Theodore Nkadimeng Mahosi
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Soon after independence on 18th April 1980, Zimbabwe’s foreign policy was shaped by the realities on the ground, which saw the country managing a sound relationship with both the Capitalist West and the Communist Eastern blocs. The post-independence foreign policy was therefore premised on security concerns illuminated by the Cold War era. This was one the reasons President Robert Mugabe adopted a policy of reconciliation and this earned his government recognition on the international platform. However, in Southern Africa apartheid South Africa was still the vanguard of capitalism and oppression such that she posed a serious threat to the newly born Zimbabwean nation which necessitated that Zimbabwe position herself both in the region and the continent to counter potential internal stability from within. Irrespective of how the international community viewed the country’s foreign policy Zimbabwe has continued to influence regional, continental and world geo-politics, especially on behalf of the developing nations. This raises a question why as a result of its foreign policy the country is now regarded a pariah state, especially some Western countries which used to applaud its political economic policies immediately after independence. Therefore, this study argues that the political economy of Zimbabwe had a far-reaching bearing on its foreign policy. For this reason, the problem necessitates the investigation of Zimbabwe’s foreign policy perspectives in Southern Africa since the turn of the 1990s. Two main theories which are Realism, Afro-centrism inform the study as an attempt to understand Zimbabwe’s foreign policy paradigm shift and perhaps provide answers to the objectives raised. The research therefore employs a qualitative approach where the conceptual nature of the study into the foreign policy of Zimbabwe is largely desktop research. However, the nature of the study will also require that oral interviews are conducted to substantiate some of the arguments advanced.Keywords: cold war set up, foreign policy, look east policy, pan-africanism, post 2000 period, Southern Africa, Zimbabwe
Procedia PDF Downloads 329967 Soret and Dufour's Effects on Mixed Convection Unsteady MHD Boundary Layer Flow over a Stretching Sheet Embedded in a Porous Medium with Chemically Reactive Spices
Authors: Deva Kanta Phukan
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An investigation is made to carry out to study the thermal-diffusion and diffusion thermo-effects in hydro-magnetic unsteady flow by a mixed convection boundary layer past an impermeable vertical stretching sheet embedded in a conducting fluid-saturated porous medium in the presence of a chemical reaction effect. The velocity of stretching surface, the surface temperature and the concentration are assumed to vary linearly with the distance along the surface. The governing partial differential equations are transformed in to self similar unsteady equations using similarity transformations and solved numerically by the Runge kutta fourth order scheme in association with the shooting method for the whole transient domain from the initial state to the final steady state flow. Numerical results for the velocity, temperature, the concentration, the skin friction , and the Nusselt and Sherwood numbers are shown graphically for various flow parameters. The results reveal that there is a smooth transition of flow from unsteady state to the final steady state. A special case of our results is in good agreement with an earlier published work.Keywords: heat and mass transfer, boundary layer flow, porous media, magnetic field, Soret number, Dufour’s number
Procedia PDF Downloads 445966 Optical Design and Modeling of Micro Light-Emitting Diodes for Display Applications
Authors: Chaya B. M., C. Dhanush, Inti Sai Srikar, Akula Pavan Parvatalu, Chirag Gowda R
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Recently, there has been a lot of interest in µ-LED technology because of its exceptional qualities, including auto emission, high visibility, low consumption of power, rapid response and longevity. Light-emitting diodes (LED) using III-nitride, such as lighting sources, visible light communication (VLC) devices, and high-power devices, are finding increasing use as miniaturization technology advances. The use of micro-LED displays in place of traditional display technologies like liquid crystal displays (LCDs) and organic light-emitting diodes (OLEDs) is one of the most prominent recent advances, which may even represent the next generation of displays. The development of fully integrated, multifunctional devices and the incorporation of extra capabilities into micro-LED displays, such as sensing, light detection, and solar cells, are the pillars of advanced technology. Due to the wide range of applications for micro-LED technology, the effectiveness and dependability of these devices in numerous harsh conditions are becoming increasingly important. Enough research has been conducted to overcome the under-effectiveness of micro-LED devices. In this paper, different Micro LED design structures are proposed in order to achieve optimized optical properties. In order to attain improved external quantum efficiency (EQE), devices' light extraction efficiency (LEE) has also been boosted.Keywords: finite difference time domain, light out coupling efficiency, far field intensity, power density, quantum efficiency, flat panel displays
Procedia PDF Downloads 79965 Study of Superconducting Patch Printed on Electric-Magnetic Substrates Materials
Authors: Fortaki Tarek, S. Bedra
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In this paper, the effects of both uniaxial anisotropy in the substrate and high Tc superconducting patch on the resonant frequency, half-power bandwidth, and radiation patterns are investigated using an electric field integral equation and the spectral domain Green’s function. The analysis has been based on a full electromagnetic wave model with London’s equations and the Gorter-Casimir two-fluid model has been improved to investigate the resonant and radiation characteristics of high Tc superconducting rectangular microstrip patch in the case where the patch is printed on electric-magnetic uniaxially anisotropic substrate materials. The stationary phase technique has been used for computing the radiation electric field. The obtained results demonstrate a considerable improvement in the half-power bandwidth, of the rectangular microstrip patch, by using a superconductor patch instead of a perfect conductor one. Further results show that high Tc superconducting rectangular microstrip patch on the uniaxial substrate with properly selected electric and magnetic anisotropy ratios is more advantageous than the one on the isotropic substrate by exhibiting wider bandwidth and radiation characteristic. This behavior agrees with that discovered experimentally for superconducting patches on isotropic substrates. The calculated results have been compared with measured one available in the literature and excellent agreement has been found.Keywords: high Tc superconducting microstrip patch, electric-magnetic anisotropic substrate, Galerkin method, surface complex impedance with boundary conditions, radiation patterns
Procedia PDF Downloads 444964 The Limits to Self-Defense Claims in Case of Domestic Violence Homicides
Authors: Maria Elisabete Costa Ferreira
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Domestic violence is a serious social issue in which victims are mostly women. Domestic violence develops in cycles, starting with the building of tension, passing through the incident of abuse and ending with reconciliation, also known as honeymoon. As time goes by, the shorter these phases become, and the greater and more severe the attacks, rarely leading to the death of the victim of abuse. Sometimes, the victim stops the abuse by killing the aggressor, usually after the immediate aggression has taken place. This poses an important obstacle to the claim of self-defense by the victim of domestic violence pending trial for the homicide of her long-time abuser. The main problem with self-defense claims in such cases is that the law requires the act of aggression to be present or imminent (imminent threat or immediate danger) so that it permits the victim to take her defense into her own hands. If the episode of aggression has already taken place, this general requirement for the admissibility of self-defense is not satisfied. This paper sheds new light on the concept of the actuality of the aggression, understanding that, since domestic violence is a permanent offense, for as long as the victim stays under the domain of the aggressor, imminent threat will be present, allowing the self-defense claim of a woman who kills her abuser in such circumstances to be admissible. An actualist interpretation of the requirement of the necessity of the means used in self-defense will be satisfied when evaluated from the subjective perspective of the intimate partner victim. Necessity will be satisfied if it is reasonable for the victim to perceive the use of lethal force as the only means to release herself from the abuser.Keywords: domestic violence, homicide, self-defense, imminent threat, necessity of lethal force
Procedia PDF Downloads 65963 Interior Design: Changing Values
Authors: Kika Ioannou Kazamia
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This paper examines the action research cycle of the second phase of longitudinal research on sustainable interior design practices, between two groups of stakeholders, designers and clients. During this phase of the action research, the second step - the change stage - of Lewin’s change management model has been utilized to change values, approaches, and attitudes toward sustainable design practices among the participants. Affective domain learning theory is utilized to attach new values. Learning with the use of information technology, collaborative learning, and problem-based learning are the learning methods implemented toward the acquisition of the objectives. Learning methods, and aims, require the design of interventions with participants' involvement in activities that would lead to the acknowledgment of the benefits of sustainable practices. Interventions are steered to measure participants’ decisions for the worth and relevance of ideas, and experiences; accept or commit to a particular stance or action. The data collection methods used in this action research are observers’ reports, participants' questionnaires, and interviews. The data analyses use both quantitative and qualitative methods. The main beneficial aspect of the quantitative method was to provide the means to separate many factors that obscured the main qualitative findings. The qualitative method allowed data to be categorized, to adapt the deductive approach, and then examine for commonalities that could reflect relevant categories or themes. The results from the data indicate that during the second phase, designers and clients' participants altered their behaviours.Keywords: design, change, sustainability, learning, practices
Procedia PDF Downloads 77962 Numerical Simulation of a Point Absorber Wave Energy Converter Using OpenFOAM in Indian Scenario
Authors: Pooja Verma, Sumana Ghosh
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There is a growing need for alternative way of power generation worldwide. The reason can be attributed to limited resources of fossil fuels, environmental pollution, increasing cost of conventional fuels, and lower efficiency of conversion of energy in existing systems. In this context, one of the potential alternatives for power generation is wave energy. However, it is difficult to estimate the amount of electrical energy generation in an irregular sea condition by experiment and or analytical methods. Therefore in this work, a numerical wave tank is developed using the computational fluid dynamics software Open FOAM. In this software a specific utility known as waves2Foam utility is being used to carry out the simulation work. The computational domain is a tank of dimension: 5m*1.5m*1m with a floating object of dimension: 0.5m*0.2m*0.2m. Regular waves are generated at the inlet of the wave tank according to Stokes second order theory. The main objective of the present study is to validate the numerical model against existing experimental data. It shows a good matching with the existing experimental data of floater displacement. Later the model is exploited to estimate energy extraction due to the movement of such a point absorber in real sea conditions. Scale down the wave properties like wave height, wave length, etc. are used as input parameters. Seasonal variations are also considered.Keywords: OpenFOAM, numerical wave tank, regular waves, floating object, point absorber
Procedia PDF Downloads 352961 PaSA: A Dataset for Patent Sentiment Analysis to Highlight Patent Paragraphs
Authors: Renukswamy Chikkamath, Vishvapalsinhji Ramsinh Parmar, Christoph Hewel, Markus Endres
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Given a patent document, identifying distinct semantic annotations is an interesting research aspect. Text annotation helps the patent practitioners such as examiners and patent attorneys to quickly identify the key arguments of any invention, successively providing a timely marking of a patent text. In the process of manual patent analysis, to attain better readability, recognising the semantic information by marking paragraphs is in practice. This semantic annotation process is laborious and time-consuming. To alleviate such a problem, we proposed a dataset to train machine learning algorithms to automate the highlighting process. The contributions of this work are: i) we developed a multi-class dataset of size 150k samples by traversing USPTO patents over a decade, ii) articulated statistics and distributions of data using imperative exploratory data analysis, iii) baseline Machine Learning models are developed to utilize the dataset to address patent paragraph highlighting task, and iv) future path to extend this work using Deep Learning and domain-specific pre-trained language models to develop a tool to highlight is provided. This work assists patent practitioners in highlighting semantic information automatically and aids in creating a sustainable and efficient patent analysis using the aptitude of machine learning.Keywords: machine learning, patents, patent sentiment analysis, patent information retrieval
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