Search results for: bidirectional encoder representations from transformers
469 Pilot Directional Protection Scheme Using Wireless Communication
Authors: Nitish Sharma, G. G. Karady
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This paper presents a scheme for the protection of loop system from all type of faults using the direction of fault current. The presence of distributed generation in today’s system increases the complexity of fault detection as the power flow is bidirectional. Hence, protection scheme specific to this purpose needs to be developed. This paper shows a fast protection scheme using communication which can be fiber optic or wireless. In this paper, the possibility of wireless communication for protection is studied to exchange the information between the relays. The negative sequence and positive sequence directional elements are used to determine the direction of fault current. A PSCAD simulation is presented and validated using commercial SEL relays.Keywords: smart grid protection, pilot protection, power system simulation, wireless communication
Procedia PDF Downloads 636468 A Systemic Review and Comparison of Non-Isolated Bi-Directional Converters
Authors: Rahil Bahrami, Kaveh Ashenayi
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This paper presents a systematic classification and comparative analysis of non-isolated bi-directional DC-DC converters. The increasing demand for efficient energy conversion in diverse applications has spurred the development of various converter topologies. In this study, we categorize bi-directional converters into three distinct classes: Inverting, Non-Inverting, and Interleaved. Each category is characterized by its unique operational characteristics and benefits. Furthermore, a practical comparison is conducted by evaluating the results of simulation of each bi-directional converter. BDCs can be classified into isolated and non-isolated topologies. Non-isolated converters share a common ground between input and output, making them suitable for applications with minimal voltage change. They are easy to integrate, lightweight, and cost-effective but have limitations like limited voltage gain, switching losses, and no protection against high voltages. Isolated converters use transformers to separate input and output, offering safety benefits, high voltage gain, and noise reduction. They are larger and more costly but are essential for automotive designs where safety is crucial. The paper focuses on non-isolated systems.The paper discusses the classification of non-isolated bidirectional converters based on several criteria. Common factors used for classification include topology, voltage conversion, control strategy, power capacity, voltage range, and application. These factors serve as a foundation for categorizing converters, although the specific scheme might vary depending on contextual, application, or system-specific requirements. The paper presents a three-category classification for non-isolated bi-directional DC-DC converters: inverting, non-inverting, and interleaved. In the inverting category, converters produce an output voltage with reversed polarity compared to the input voltage, achieved through specific circuit configurations and control strategies. This is valuable in applications such as motor control and grid-tied solar systems. The non-inverting category consists of converters maintaining the same voltage polarity, useful in scenarios like battery equalization. Lastly, the interleaved category employs parallel converter stages to enhance power delivery and reduce current ripple. This classification framework enhances comprehension and analysis of non-isolated bi-directional DC-DC converters. The findings contribute to a deeper understanding of the trade-offs and merits associated with different converter types. As a result, this work aids researchers, practitioners, and engineers in selecting appropriate bi-directional converter solutions for specific energy conversion requirements. The proposed classification framework and experimental assessment collectively enhance the comprehension of non-isolated bi-directional DC-DC converters, fostering advancements in efficient power management and utilization.The simulation process involves the utilization of PSIM to model and simulate non-isolated bi-directional converter from both inverted and non-inverted category. The aim is to conduct a comprehensive comparative analysis of these converters, considering key performance indicators such as rise time, efficiency, ripple factor, and maximum error. This systematic evaluation provides valuable insights into the dynamic response, energy efficiency, output stability, and overall precision of the converters. The results of this comparison facilitate informed decision-making and potential optimizations, ensuring that the chosen converter configuration aligns effectively with the designated operational criteria and performance goals.Keywords: bi-directional, DC-DC converter, non-isolated, energy conversion
Procedia PDF Downloads 100467 Influence of Harmonics on Medium Voltage Distribution System: A Case Study for Residential Area
Authors: O. Arikan, C. Kocatepe, G. Ucar, Y. Hacialiefendioglu
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In this paper, influence of harmonics on medium voltage distribution system of Bogazici Electricity Distribution Inc. (BEDAS) which takes place at Istanbul/Turkey is investigated. A ring network consisting of residential loads is taken into account for this study. Real system parameters and measurement results are used for simulations. Also, probable working conditions of the system are analyzed for %50, %75 and %100 loading of transformers with similar harmonic contents. Results of the study are exhibited the influence of nonlinear loads on %THDV, P.F. and technical losses of the medium voltage distribution system.Keywords: distribution system, harmonic, technical losses, power factor, total harmonic distortion, residential load, medium voltage
Procedia PDF Downloads 573466 Design and Control Algorithms for Power Electronic Converters for EV Applications
Authors: Ilya Kavalchuk, Mehdi Seyedmahmoudian, Ben Horan, Aman Than Oo, Alex Stojcevski
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The power electronic components within Electric Vehicles (EV) need to operate in several important modes. Some modes directly influence safety, while others influence vehicle performance. Given the variety of functions and operational modes required of the power electronics, it needs to meet efficiency requirements to minimize power losses. Another challenge in the control and construction of such systems is the ability to support bidirectional power flow. This paper considers the construction, operation, and feasibility of available converters for electric vehicles with feasible configurations of electrical buses and loads. This paper describes logic and control signals for the converters for different operations conditions based on the efficiency and energy usage bases.Keywords: electric vehicles, electrical machines control, power electronics, powerflow regulations
Procedia PDF Downloads 560465 Stock Price Prediction with 'Earnings' Conference Call Sentiment
Authors: Sungzoon Cho, Hye Jin Lee, Sungwhan Jeon, Dongyoung Min, Sungwon Lyu
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Major public corporations worldwide use conference calls to report their quarterly earnings. These 'earnings' conference calls allow for questions from stock analysts. We investigated if it is possible to identify sentiment from the call script and use it to predict stock price movement. We analyzed call scripts from six companies, two each from Korea, China and Indonesia during six years 2011Q1 – 2017Q2. Random forest with Frequency-based sentiment scores using Loughran MacDonald Dictionary did better than control model with only financial indicators. When the stock prices went up 20 days from earnings release, our model predicted correctly 77% of time. When the model predicted 'up,' actual stock prices went up 65% of time. This preliminary result encourages us to investigate advanced sentiment scoring methodologies such as topic modeling, auto-encoder, and word2vec variants.Keywords: earnings call script, random forest, sentiment analysis, stock price prediction
Procedia PDF Downloads 292464 The Relationship between Representational Conflicts, Generalization, and Encoding Requirements in an Instance Memory Network
Authors: Mathew Wakefield, Matthew Mitchell, Lisa Wise, Christopher McCarthy
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The properties of memory representations in artificial neural networks have cognitive implications. Distributed representations that encode instances as a pattern of activity across layers of nodes afford memory compression and enforce the selection of a single point in instance space. These encoding schemes also appear to distort the representational space, as well as trading off the ability to validate that input information is within the bounds of past experience. In contrast, a localist representation which encodes some meaningful information into individual nodes in a network layer affords less memory compression while retaining the integrity of the representational space. This allows the validity of an input to be determined. The validity (or familiarity) of input along with the capacity of localist representation for multiple instance selections affords a memory sampling approach that dynamically balances the bias-variance trade-off. When the input is familiar, bias may be high by referring only to the most similar instances in memory. When the input is less familiar, variance can be increased by referring to more instances that capture a broader range of features. Using this approach in a localist instance memory network, an experiment demonstrates a relationship between representational conflict, generalization performance, and memorization demand. Relatively small sampling ranges produce the best performance on a classic machine learning dataset of visual objects. Combining memory validity with conflict detection produces a reliable confidence judgement that can separate responses with high and low error rates. Confidence can also be used to signal the need for supervisory input. Using this judgement, the need for supervised learning as well as memory encoding can be substantially reduced with only a trivial detriment to classification performance.Keywords: artificial neural networks, representation, memory, conflict monitoring, confidence
Procedia PDF Downloads 127463 A Collaborative Problem Driven Approach to Design an HR Analytics Application
Authors: L. Atif, C. Rosenthal-Sabroux, M. Grundstein
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The requirements engineering process is a crucial phase in the design of complex systems. The purpose of our research is to present a collaborative problem-driven requirements engineering approach that aims at improving the design of a Decision Support System as an Analytics application. This approach has been adopted to design a Human Resource management DSS. The Requirements Engineering process is presented as a series of guidelines for activities that must be implemented to assure that the final product satisfies end-users requirements and takes into account the limitations identified. For this, we know that a well-posed statement of the problem is “a problem whose crucial character arises from collectively produced estimation and a formulation found to be acceptable by all the parties”. Moreover, we know that DSSs were developed to help decision-makers solve their unstructured problems. So, we thus base our research off of the assumption that developing DSS, particularly for helping poorly structured or unstructured decisions, cannot be done without considering end-user decision problems, how to represent them collectively, decisions content, their meaning, and the decision-making process; thus, arise the field issues in a multidisciplinary perspective. Our approach addresses a problem-driven and collaborative approach to designing DSS technologies: It will reflect common end-user problems in the upstream design phase and in the downstream phase these problems will determine the design choices and potential technical solution. We will thus rely on a categorization of HR’s problems for a development mirroring the Analytics solution. This brings out a new data-driven DSS typology: Descriptive Analytics, Explicative or Diagnostic Analytics, Predictive Analytics, Prescriptive Analytics. In our research, identifying the problem takes place with design of the solution, so, we would have to resort a significant transformations of representations associated with the HR Analytics application to build an increasingly detailed representation of the goal to be achieved. Here, the collective cognition is reflected in the establishment of transfer functions of representations during the whole of the design process.Keywords: DSS, collaborative design, problem-driven requirements, analytics application, HR decision making
Procedia PDF Downloads 295462 Measurement of Magnetic Properties of Grainoriented Electrical Steels at Low and High Fields Using a Novel Single
Authors: Nkwachukwu Chukwuchekwa, Joy Ulumma Chukwuchekwa
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Magnetic characteristics of grain-oriented electrical steel (GOES) are usually measured at high flux densities suitable for its typical applications in power transformers. There are limited magnetic data at low flux densities which are relevant for the characterization of GOES for applications in metering instrument transformers and low frequency magnetic shielding in magnetic resonance imaging medical scanners. Magnetic properties such as coercivity, B-H loop, AC relative permeability and specific power loss of conventional grain oriented (CGO) and high permeability grain oriented (HGO) electrical steels were measured and compared at high and low flux densities at power magnetising frequency. 40 strips comprising 20 CGO and 20 HGO, 305 mm x 30 mm x 0.27 mm from a supplier were tested. The HGO and CGO strips had average grain sizes of 9 mm and 4 mm respectively. Each strip was singly magnetised under sinusoidal peak flux density from 8.0 mT to 1.5 T at a magnetising frequency of 50 Hz. The novel single sheet tester comprises a personal computer in which LabVIEW version 8.5 from National Instruments (NI) was installed, a NI 4461 data acquisition (DAQ) card, an impedance matching transformer, to match the 600 minimum load impedance of the DAQ card with the 5 to 20 low impedance of the magnetising circuit, and a 4.7 Ω shunt resistor. A double vertical yoke made of GOES which is 290 mm long and 32 mm wide is used. A 500-turn secondary winding, about 80 mm in length, was wound around a plastic former, 270 mm x 40 mm, housing the sample, while a 100-turn primary winding, covering the entire length of the plastic former was wound over the secondary winding. A standard Epstein strip to be tested is placed between the yokes. The magnetising voltage was generated by the LabVIEW program through a voltage output from the DAQ card. The voltage drop across the shunt resistor and the secondary voltage were acquired by the card for calculation of magnetic field strength and flux density respectively. A feedback control system implemented in LabVIEW was used to control the flux density and to make the induced secondary voltage waveforms sinusoidal to have repeatable and comparable measurements. The low noise NI4461 card with 24 bit resolution and a sampling rate of 204.8 KHz and 92 KHz bandwidth were chosen to take the measurements to minimize the influence of thermal noise. In order to reduce environmental noise, the yokes, sample and search coil carrier were placed in a noise shielding chamber. HGO was found to have better magnetic properties at both high and low magnetisation regimes. This is because of the higher grain size of HGO and higher grain-grain misorientation of CGO. HGO is better CGO in both low and high magnetic field applications.Keywords: flux density, electrical steel, LabVIEW, magnetization
Procedia PDF Downloads 291461 Consumers Perception of Slogans/ Taglines: A Study of Higher Education Sector in India
Authors: Puja Mahesh
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Purpose: A good slogan captures the essence of your brand's promised consumer benefit in one short phrase. A good slogan conjures up positive imagery about your business or your product. A good slogan has the element of immediacy. Immediacy does not necessarily mean that the slogan will inspire consumers to run right out and buy your product. It does mean, however, that your slogan has an immediate cognitive impact. It forces your audience to "stop-and-think" after exposure as a necessary first step toward remembering your slogan promise. A good slogan is memorable and durability. When your slogan promise is occupying prime real estate in the consumer's subconscious, it aids in recall and activates preference for your brand when you want it -when consumers are ready to buy. The objective of current study is to understand the consumer perception of slogans/taglines of higher education sector in India. Design/Methodology/Approach: Survey of 500 consumers (largely comprising of youth) will be done using questionnaire. Universities and institutes will be chosen on the basis of various streams and Credible Rankings. The perception will be taken from the respondents on the basis of scale. Findings: Catchy phrases, rhymes, music, jingles, avatars (visual representations) and unique imagery are just a few of the mnemonic clutter-busting tactics commonly used in slogans to stand apart from the competition and to aid in memory recall. The study will reveal whether it is true that catchy phrases, rhymes, music, jingles, avatars (visual representations) and unique imagery across disciplines and universities help in building stronger brands. It will also be found whether consumers pay more attention to reputation of University/ College or brand identity. Originality/Value: Researcher has not come across any study of Consumer Perception of Slogans/Taglines of Higher Education Brands in India. Also, it would be interesting to understand Consumer Perception of various colleges/streams particularly Management colleges who invest a lot of time in branding exercise.Keywords: consumer perception, higher education, slogans, taglines
Procedia PDF Downloads 424460 Unsupervised Domain Adaptive Text Retrieval with Query Generation
Authors: Rui Yin, Haojie Wang, Xun Li
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Recently, mainstream dense retrieval methods have obtained state-of-the-art results on some datasets and tasks. However, they require large amounts of training data, which is not available in most domains. The severe performance degradation of dense retrievers on new data domains has limited the use of dense retrieval methods to only a few domains with large training datasets. In this paper, we propose an unsupervised domain-adaptive approach based on query generation. First, a generative model is used to generate relevant queries for each passage in the target corpus, and then the generated queries are used for mining negative passages. Finally, the query-passage pairs are labeled with a cross-encoder and used to train a domain-adapted dense retriever. Experiments show that our approach is more robust than previous methods in target domains that require less unlabeled data.Keywords: dense retrieval, query generation, unsupervised training, text retrieval
Procedia PDF Downloads 73459 An Analysis of the Representation of the Translator and Translation Process into Brazilian Social Networking Groups
Authors: Érica Lima
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In the digital era, in which we have an avalanche of information, it is not new that the Internet has brought new modes of communication and knowledge access. Characterized by the multiplicity of discourses, opinions, beliefs and cultures, the web is a space of political-ideological dimensions where people (who often do not know each other) interact and create representations, deconstruct stereotypes, and redefine identities. Currently, the translator needs to be able to deal with digital spaces ranging from specific software to social media, which inevitably impact on his professional life. One of the most impactful ways of being seen in cyberspace is the participation in social networking groups. In addition to its ability to disseminate information among participants, social networking groups allow a significant personal and social exposure. Such exposure is due to the visibility of each participant achieved not only on its personal profile page, but also in each comment or post the person makes in the groups. The objective of this paper is to study the representations of translators and translation process on the Internet, more specifically in publications in two Brazilian groups of great influence on the Facebook: "Translators/Interpreters" and "Translators, Interpreters and Curious". These chosen groups represent the changes the network has brought to the profession, including the way translators are seen and see themselves. The analyzed posts allowed a reading of what common sense seems to think about the translator as opposed to what the translators seem to think about themselves as a professional class. The results of the analysis lead to the conclusion that these two positions are antagonistic and sometimes represent conflict of interests: on the one hand, the society in general consider the translator’s work something easy, therefore it is not necessary to be well remunerated; on the other hand, the translators who know how complex a translation process is and how much it takes to be a good professional. The results also reveal that social networking sites such as Facebook provide more visibility, but it takes a more active role from the translator to achieve a greater appreciation of the profession and more recognition of the role of the translator, especially in face of increasingly development of automatic translation programs.Keywords: Facebook, social representation, translation, translator
Procedia PDF Downloads 148458 Field Experience with Sweep Frequency Response Analysis for Power Transformer Diagnosis
Authors: Ambuj Kumar, Sunil Kumar Singh, Shrikant Singh, Zakir Husain, R. K. Jarial
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Sweep frequency response analysis has been turning out a powerful tool for investigation of mechanical as well as electrical integration of transformers. In this paper various aspect of practical application of SFRA has been studied. Open circuit and short circuit measurement were done on different phases of high voltage and low voltage winding. A case study was presented for the transformer of rating 31.5 MVA for various frequency ranges. A clear picture was presented for sub- frequency ranges for HV as well as LV winding. The main motive of work is to investigate high voltage short circuit response. The theoretical concept about SFRA responses is validated with expert system software results.Keywords: transformer winding, SFRA, OCT & SCT, frequency deviation
Procedia PDF Downloads 957457 Performance Comparison of Space-Time Block and Trellis Codes under Rayleigh Channels
Authors: Jing Qingfeng, Wu Jiajia
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Due to the crowded orbits and shortage of frequency resources, utilizing of MIMO technology to improve spectrum efficiency and increase the capacity has become a necessary trend of broadband satellite communication. We analyze the main influenced factors and compare the BER performance of space-time block code (STBC) scheme and space-time trellis code (STTC) scheme. This paper emphatically studies the bit error rate (BER) performance of STTC and STBC under Rayleigh channel. The main emphasis is placed on the effects of the factors, such as terminal environment and elevation angles, on the BER performance of STBC and STTC schemes. Simulation results indicate that performance of STTC under Rayleigh channel is obviously improved with the increasing of transmitting and receiving antennas numbers, but the encoder state has little impact on the performance. Under Rayleigh channel, performance of Alamouti code is better than that of STTC.Keywords: MIMO, space time block code (STBC), space time trellis code (STTC), Rayleigh channel
Procedia PDF Downloads 349456 Contemporary Anti-Gypsyism in European Mass Media
Authors: Elisabetta Di Giovanni
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This paper focuses on the contemporary phenomenon of Anti-Gypsyism which is widely diffused on social representations of the so called 'Gypsies'. In Europe and especially in Italy, media tend to reproduce racist stereotypes and prejudices through a xenophobic depiction of this ethnic group, often offering an ethnocentric point of view. From an anthropological perspective, Roma people are a minority group actually facing diasporic phenomena in all Europe, produced by the host society.Keywords: Roma people, anti-gypsyism, ethnocentrism, mass media
Procedia PDF Downloads 405455 A Systematic Review on Challenges in Big Data Environment
Authors: Rimmy Yadav, Anmol Preet Kaur
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Big Data has demonstrated the vast potential in streamlining, deciding, spotting business drifts in different fields, for example, producing, fund, Information Technology. This paper gives a multi-disciplinary diagram of the research issues in enormous information and its procedures, instruments, and system identified with the privacy, data storage management, network and energy utilization, adaptation to non-critical failure and information representations. Other than this, result difficulties and openings accessible in this Big Data platform have made.Keywords: big data, privacy, data management, network and energy consumption
Procedia PDF Downloads 312454 Capacitive Coupling Wireless Power Transfer System with 6.78 MHz Class D Inverter
Authors: Kang Hyun Yi
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Wireless power transfer technologies are inductive coupling, magnetic resonance, and capacitive coupling methods, typically. Among them, the capacitive coupling wireless power transfer, also named Capacitive Coupling Wireless Power Transfer (CCWPT), has been researched to overcome the drawbacks of other approaches. The CCWPT has many advantages such as a simple structure, low standing power loss, reduced Electromagnetic Interference (EMI) and the ability to transfer power through metal barriers. In this paper, the CCWPT system with 6.78MHz class D inverter is proposed and analyzed. The proposed system is consisted of the 6.78MHz class D inverter with the LC low pass filter, the capacitor between a transmitter and a receiver and impedance transformers. The system is verified with a prototype for charging mobile devices.Keywords: wireless power transfer, capacitive coupling power transfer, class D inverter, 6.78MHz
Procedia PDF Downloads 651453 Resisting Adversarial Assaults: A Model-Agnostic Autoencoder Solution
Authors: Massimo Miccoli, Luca Marangoni, Alberto Aniello Scaringi, Alessandro Marceddu, Alessandro Amicone
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The susceptibility of deep neural networks (DNNs) to adversarial manipulations is a recognized challenge within the computer vision domain. Adversarial examples, crafted by adding subtle yet malicious alterations to benign images, exploit this vulnerability. Various defense strategies have been proposed to safeguard DNNs against such attacks, stemming from diverse research hypotheses. Building upon prior work, our approach involves the utilization of autoencoder models. Autoencoders, a type of neural network, are trained to learn representations of training data and reconstruct inputs from these representations, typically minimizing reconstruction errors like mean squared error (MSE). Our autoencoder was trained on a dataset of benign examples; learning features specific to them. Consequently, when presented with significantly perturbed adversarial examples, the autoencoder exhibited high reconstruction errors. The architecture of the autoencoder was tailored to the dimensions of the images under evaluation. We considered various image sizes, constructing models differently for 256x256 and 512x512 images. Moreover, the choice of the computer vision model is crucial, as most adversarial attacks are designed with specific AI structures in mind. To mitigate this, we proposed a method to replace image-specific dimensions with a structure independent of both dimensions and neural network models, thereby enhancing robustness. Our multi-modal autoencoder reconstructs the spectral representation of images across the red-green-blue (RGB) color channels. To validate our approach, we conducted experiments using diverse datasets and subjected them to adversarial attacks using models such as ResNet50 and ViT_L_16 from the torch vision library. The autoencoder extracted features used in a classification model, resulting in an MSE (RGB) of 0.014, a classification accuracy of 97.33%, and a precision of 99%.Keywords: adversarial attacks, malicious images detector, binary classifier, multimodal transformer autoencoder
Procedia PDF Downloads 113452 A Bathtub Curve from Nonparametric Model
Authors: Eduardo C. Guardia, Jose W. M. Lima, Afonso H. M. Santos
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This paper presents a nonparametric method to obtain the hazard rate “Bathtub curve” for power system components. The model is a mixture of the three known phases of a component life, the decreasing failure rate (DFR), the constant failure rate (CFR) and the increasing failure rate (IFR) represented by three parametric Weibull models. The parameters are obtained from a simultaneous fitting process of the model to the Kernel nonparametric hazard rate curve. From the Weibull parameters and failure rate curves the useful lifetime and the characteristic lifetime were defined. To demonstrate the model the historic time-to-failure of distribution transformers were used as an example. The resulted “Bathtub curve” shows the failure rate for the equipment lifetime which can be applied in economic and replacement decision models.Keywords: bathtub curve, failure analysis, lifetime estimation, parameter estimation, Weibull distribution
Procedia PDF Downloads 446451 Searching for the ‘Why’ of Gendered News: Journalism Practices and Societal Contexts
Authors: R. Simões, M. Silveirinha
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Driven by the need to understand the results of previous research that clearly shows deep unbalances of the media discourses about women and men in spite of the growing numbers of female journalists, our paper aims to progress from the 'what' to the 'why' of these unbalanced representations. Furthermore, it does so at a time when journalism is undergoing a dramatic change in terms of professional practices and in how media organizations are organized and run, affecting women in particular. While some feminist research points to the fact that female and male journalists evaluate the role of the news and production methods in similar ways feminist theorizing also suggests that thought and knowledge are highly influenced by social identity, which is also inherently affected by the experiences of gender. This is particularly important at a time of deep societal and professional changes. While there are persuasive discussions of gender identities at work in newsrooms in various countries studies on the issue will benefit from cases that focus on the particularities of local contexts. In our paper, we present one such case: the case of Portugal, a country hit hard by austerity measures that have affected all cultural industries including journalism organizations, already feeling the broader impacts of the larger societal changes of the media landscape. Can we gender these changes? How are they felt and understood by female and male journalists? And how are these discourses framed by androcentric, feminist and post-feminist sensibilities? Foregrounding questions of gender, our paper seeks to explore some of the interactions of societal and professional forces, identifying their gendered character and outlining how they shape journalism work in general and the production of unbalanced gender representations in particular. We do so grounded in feminist studies of journalism as well as feminist organizational and work studies, looking at a corpus of 20 in-depth interviews of female and male Portuguese journalists. The research findings illustrate how gender in journalism practices interacts with broader experiences of the cultural and economic contexts and show the ambivalences of these interactions in news organizations.Keywords: gender, journalism, newsroom culture, Portuguese journalists
Procedia PDF Downloads 399450 Large-Scale Electroencephalogram Biometrics through Contrastive Learning
Authors: Mostafa ‘Neo’ Mohsenvand, Mohammad Rasool Izadi, Pattie Maes
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EEG-based biometrics (user identification) has been explored on small datasets of no more than 157 subjects. Here we show that the accuracy of modern supervised methods falls rapidly as the number of users increases to a few thousand. Moreover, supervised methods require a large amount of labeled data for training which limits their applications in real-world scenarios where acquiring data for training should not take more than a few minutes. We show that using contrastive learning for pre-training, it is possible to maintain high accuracy on a dataset of 2130 subjects while only using a fraction of labels. We compare 5 different self-supervised tasks for pre-training of the encoder where our proposed method achieves the accuracy of 96.4%, improving the baseline supervised models by 22.75% and the competing self-supervised model by 3.93%. We also study the effects of the length of the signal and the number of channels on the accuracy of the user-identification models. Our results reveal that signals from temporal and frontal channels contain more identifying features compared to other channels.Keywords: brainprint, contrastive learning, electroencephalo-gram, self-supervised learning, user identification
Procedia PDF Downloads 157449 Simulation and Analytical Investigation of Different Combination of Single Phase Power Transformers
Authors: M. Salih Taci, N. Tayebi, I. Bozkır
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In this paper, the equivalent circuit of the ideal single-phase power transformer with its appropriate voltage current measurement was presented. The calculated values of the voltages and currents of the different connections single phase normal transformer and the results of the simulation process are compared. As it can be seen, the calculated results are the same as the simulated results. This paper includes eight possible different transformer connections. Depending on the desired voltage level, step-down and step-up application transformer is considered. Modelling and analysis of a system consisting of an equivalent source, transformer (primary and secondary), and loads are performed to investigate the combinations. The obtained values are simulated in PSpice environment and then how the currents, voltages and phase angle are distributed between them is explained based on calculation.Keywords: transformer, simulation, equivalent model, parallel series combinations
Procedia PDF Downloads 361448 Innocent Victims and Immoral Women: Sex Workers in the Philippines through the Lens of Mainstream Media
Authors: Sharmila Parmanand
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This paper examines dominant media representations of prostitution in the Philippines and interrogates sex workers’ interactions with the media establishment. This analysis of how sex workers are constituted in media, often as both innocent victims and immoral actors, contributes to an understanding of public discourse on sex work in the Philippines, where decriminalisation has recently been proposed and sex workers are currently classified as potential victims under anti-trafficking laws but also as criminals under the penal code. The first part is an analysis of media coverage of two prominent themes on prostitution: first, raid and rescue operations conducted by law enforcement; and second, prostitution on military bases and tourism hotspots. As a result of pressure from activists and international donors, these two themes often define the policy conversations on sex work in the Philippines. The discourses in written and televised news reports and documentaries from established local and international media sources that address these themes are explored through content analysis. Conclusions are drawn based on specific terms commonly used to refer to sex workers, how sex workers are seen as performing their cultural roles as mothers and wives, how sex work is depicted, associations made between sex work and public health, representations of clients and managers and ‘rescuers’ such as the police, anti-trafficking organisations, and faith-based groups, and which actors are presumed to be issue experts. Images of how prostitution is used as a metaphor for relations between the Philippines and foreign nations are also deconstructed, along with common tropes about developing world female subjects. In general, sex workers are simultaneously portrayed as bad mothers who endanger their family’s morality but also as long-suffering victims who endure exploitation for the sake of their children. They are also depicted as unclean, drug-addicted threats to public health. Their managers and clients are portrayed as cold, abusive, and sometimes violent, and their rescuers as moral and altruistic agents who are essential for sex workers’ rehabilitation and restoration as virtuous citizens. The second part explores sex workers’ own perceptions of their interactions with media, through interviews with members of the Philippine Sex Workers Collective, a loose organisation of sex workers around the Philippines. They reveal that they are often excluded by media practitioners and that they do not feel that they have space for meaningful self-revelation about their work when they do engage with journalists, who seem to have an overt agenda of depicting them as either victims or women of loose morals. In their assessment, media narratives do not necessarily reflect their lived experiences, and in some cases, coverage of rescues and raid operations endangers their privacy and instrumentalises their suffering. Media representations of sex workers may produce subject positions such as ‘victims’ or ‘criminals’ and legitimize specific interventions while foreclosing other ways of thinking. Further, in light of media’s power to reflect and shape public consciousness, it is a valuable academic and political project to examine whether sex workers are able to assert agency in determining how they are represented.Keywords: discourse analysis, news media, sex work, trafficking
Procedia PDF Downloads 393447 Heterogenous Dimensional Super Resolution of 3D CT Scans Using Transformers
Authors: Helen Zhang
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Accurate segmentation of the airways from CT scans is crucial for early diagnosis of lung cancer. However, the existing airway segmentation algorithms often rely on thin-slice CT scans, which can be inconvenient and costly. This paper presents a set of machine learning-based 3D super-resolution algorithms along heterogeneous dimensions to improve the resolution of thicker CT scans to reduce the reliance on thin-slice scans. To evaluate the efficacy of the super-resolution algorithms, quantitative assessments using PSNR (Peak Signal to Noise Ratio) and SSIM (Structural SIMilarity index) were performed. The impact of super-resolution on airway segmentation accuracy is also studied. The proposed approach has the potential to make airway segmentation more accessible and affordable, thereby facilitating early diagnosis and treatment of lung cancer.Keywords: 3D super-resolution, airway segmentation, thin-slice CT scans, machine learning
Procedia PDF Downloads 117446 Media, Politics and Power in the Representation of the Refugee and Migration Crisis in Europe
Authors: Evangelia-Matroni Tomara
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This thesis answers the question whether the media representations and reporting in 2015-2016 - especially, after the image of the drowned three-year-old Syrian boy in the Mediterranean Sea which made global headlines in the beginning of September 2015 -, the European Commission regulatory sources material and related reporting, have the power to challenge the conceptualization of humanitarianism or even redefine it. The theoretical foundations of the thesis are based on humanitarianism and its core definitions, the power of media representations and the relative portrayal of migrants, refugees and/or asylum seekers, as well as the dominant migration discourse and EU migration governance. Using content analysis for the media portrayal of migrants (436 newspaper articles) and qualitative content analysis for the European Commission Communication documents from May 2015 until June 2016 that required various depths of interpretation, this thesis allowed us to revise the concept of humanitarianism, realizing that the current crisis may seem to be a turning point for Europe but is not enough to overcome the past hostile media discourses and suppress the historical perspective of security and control-oriented EU migration policies. In particular, the crisis helped to shift the intensity of hostility and the persistence in the state-centric, border-oriented securitization in Europe into a narration of victimization rather than threat where mercy and charity dynamics are dominated and into operational mechanisms, noting the emergency of immediate management of the massive migrations flows, respectively. Although, the understanding of a rights-based response to the ongoing migration crisis, is being followed discursively in both political and media stage, the nexus described, points out that the binary between ‘us’ and ‘them’ still exists, with only difference that the ‘invaders’ are now ‘pathetic’ but still ‘invaders’. In this context, the migration crisis challenges the concept of humanitarianism because rights dignify migrants as individuals only in a discursive or secondary level while the humanitarian work is mostly related with the geopolitical and economic interests of the ‘savior’ states.Keywords: European Union politics, humanitarianism, immigration, media representation, policy-making, refugees, security studies
Procedia PDF Downloads 293445 Integrable Heisenberg Ferromagnet Equations with Self-Consistent Potentials
Authors: Gulgassyl Nugmanova, Zhanat Zhunussova, Kuralay Yesmakhanova, Galya Mamyrbekova, Ratbay Myrzakulov
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In this paper, we consider some integrable Heisenberg Ferromagnet Equations with self-consistent potentials. We study their Lax representations. In particular we derive their equivalent counterparts in the form of nonlinear Schr\"odinger type equations. We present the integrable reductions of the Heisenberg Ferromagnet Equations with self-consistent potentials. These integrable Heisenberg Ferromagnet Equations with self-consistent potentials describe nonlinear waves in ferromagnets with some additional physical fields.Keywords: Heisenberg Ferromagnet equations, soliton equations, equivalence, Lax representation
Procedia PDF Downloads 457444 Mathematical Competence as It Is Defined through Learners' Errors in Arithmetic and Algebra
Authors: Michael Lousis
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Mathematical competence is the great aim of every mathematical teaching and learning endeavour. This can be defined as an idealised conceptualisation of the quality of cognition and the ability of implementation in practice of the mathematical subject matter, which is included in the curriculum, and is displayed only through performance of doing mathematics. The present study gives a clear definition of mathematical competence in the domains of Arithmetic and Algebra that stems from the explanation of the learners’ errors in these domains. The learners, whose errors are explained, were Greek and English participants of a large, international, longitudinal, comparative research program entitled the Kassel Project. The participants’ errors emerged as results of their work in dealing with mathematical questions and problems of the tests, which were presented to them. The construction of the tests was such as only the outcomes of the participants’ work was to be encompassed and not their course of thinking, which resulted in these outcomes. The intention was that the tests had to provide undeviating comparable results and simultaneously avoid any probable bias. Any bias could stem from obtaining results by involving so many markers from different countries and cultures, with so many different belief systems concerning the assessment of learners’ course of thinking. In this way the validity of the research was protected. This fact forced the implementation of specific research methods and theoretical prospects to take place in order the participants’ erroneous way of thinking to be disclosed. These were Methodological Pragmatism, Symbolic Interactionism, Philosophy of Mind and the ideas of Computationalism, which were used for deciding and establishing the grounds of the adequacy and legitimacy of the obtained kinds of knowledge through the explanations given by the error analysis. The employment of this methodology and of these theoretical prospects resulted in the definition of the learners’ mathematical competence, which is the thesis of the present study. Thus, learners’ mathematical competence is depending upon three key elements that should be developed in their minds: appropriate representations, appropriate meaning, and appropriate developed schemata. This definition then determined the development of appropriate teaching practices and interventions conducive to the achievement and finally the entailment of mathematical competence.Keywords: representations, meaning, appropriate developed schemata, computationalism, error analysis, explanations for the probable causes of the errors, Kassel Project, mathematical competence
Procedia PDF Downloads 268443 Efficient Fake News Detection Using Machine Learning and Deep Learning Approaches
Authors: Chaima Babi, Said Gadri
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The rapid increase in fake news continues to grow at a very fast rate; this requires implementing efficient techniques that allow testing the re-liability of online content. For that, the current research strives to illuminate the fake news problem using deep learning DL and machine learning ML ap-proaches. We have developed the traditional LSTM (Long short-term memory), and the bidirectional BiLSTM model. A such process is to perform a training task on almost of samples of the dataset, validate the model on a subset called the test set to provide an unbiased evaluation of the final model fit on the training dataset, then compute the accuracy of detecting classifica-tion and comparing the results. For the programming stage, we used Tensor-Flow and Keras libraries on Python to support Graphical Processing Units (GPUs) that are being used for developing deep learning applications.Keywords: machine learning, deep learning, natural language, fake news, Bi-LSTM, LSTM, multiclass classification
Procedia PDF Downloads 95442 Expressing Locality in Learning English: A Study of English Textbooks for Junior High School Year VII-IX in Indonesia Context
Authors: Agnes Siwi Purwaning Tyas, Dewi Cahya Ambarwati
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This paper concerns the language learning that develops as a habit formation and a constructive process while exercising an oppressive power to construct the learners. As a locus of discussion, the investigation problematizes the transfer of English language to Indonesian students of junior high school through the use of English textbooks ‘Real Time: An Interactive English Course for Junior High School Students Year VII-IX’. English language has long performed as a global language and it is a demand upon the non-English native speakers to master the language if they desire to become internationally recognized individuals. Generally, English teachers teach the language in accordance with the nature of language learning in which they are trained and expected to teach the language within the culture of the target language. This provides a potential soft cultural penetration of a foreign ideology through language transmission. In the context of Indonesia, learning English as international language is considered dilemmatic. Most English textbooks in Indonesia incorporate cultural elements of the target language which in some extent may challenge the sensitivity towards local cultural values. On the other hand, local teachers demand more English textbooks for junior high school students which can facilitate cultural dissemination of both local and global values and promote learners’ cultural traits of both cultures to avoid misunderstanding and confusion. It also aims to support language learning as bidirectional process instead of instrument of oppression. However, sensitizing and localizing this foreign language is not sufficient to restrain its soft infiltration. In due course, domination persists making the English language as an authoritative language and positioning the locality as ‘the other’. Such critical premise has led to a discursive analysis referring to how the cultural elements of the target language are presented in the textbooks and whether the local characteristics of Indonesia are able to gradually reduce the degree of the foreign oppressive ideology. The three textbooks researched were written by non-Indonesian author edited by two Indonesia editors published by a local commercial publishing company, PT Erlangga. The analytical elaboration examines the cultural characteristics in the forms of names, terminologies, places, objects and imageries –not the linguistic aspect– of both cultural domains; English and Indonesia. Comparisons as well as categorizations were made to identify the cultural traits of each language and scrutinize the contextual analysis. In the analysis, 128 foreign elements and 27 local elements were found in textbook for grade VII, 132 foreign elements and 23 local elements were found in textbook for grade VIII, while 144 foreign elements and 35 local elements were found in grade IX textbook, demonstrating the unequal distribution of both cultures. Even though the ideal pedagogical approach of English learning moves to a different direction by the means of inserting local elements, the learners are continuously imposed to the culture of the target language and forced to internalize the concept of values under the influence of the target language which tend to marginalize their native culture.Keywords: bidirectional process, English, local culture, oppression
Procedia PDF Downloads 267441 Bit Error Rate Performance of MIMO Systems for Wireless Communications
Authors: E. Ghayoula, M. Haj Taieb, A. Bouallegue, J. Y. Chouinard, R. Ghayoula
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This paper evaluates the bit error rate (BER) performance of MIMO systems for wireless communication. MIMO uses multiple transmitting antennas, multiple receiving antennas and the space-time block codes to provide diversity. MIMO transmits signal encoded by space-time block (STBC) encoder through different transmitting antennas. These signals arrive at the receiver at slightly different times. Spatially separated multiple receiving antennas are employed to provide diversity reception to combat the effect of fading in the channel. This paper presents a detailed study of diversity coding for MIMO systems. STBC techniques are implemented and simulation results in terms of the BER performance with varying number of MIMO transmitting and receiving antennas are presented. Our results show how increasing the number of both transmit and receive antenna improves system performance and reduces the bit error rate.Keywords: MIMO systems, diversity, BER, MRRC, SIMO, MISO, STBC, alamouti, SNR
Procedia PDF Downloads 490440 Some Results on Generalized Janowski Type Functions
Authors: Fuad Al Sarari
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The purpose of the present paper is to study subclasses of analytic functions which generalize the classes of Janowski functions introduced by Polatoglu. We study certain convolution conditions. This leads to a study of the sufficient condition and the neighborhood results related to the functions in the class S (T; H; F ): and a study of new subclasses of analytic functions that are defined using notions of the generalized Janowski classes and -symmetrical functions. In the quotient of analytical representations of starlikeness and convexity with respect to symmetric points, certain inherent properties are pointed out.Keywords: convolution conditions, subordination, Janowski functions, starlike functions, convex functions
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