Center of Mass Energy of the Collision for Two General Geodesic Particles Around a Kerr-Newman-Taub-NUT Black Hole

In this paper, we investigate the center of mass energy of the collision for two neutral particles with different rest masses falling freely from rest at infinity in the background of a Kerr-Newman-Taub-NUT black hole. Further, we discuss the center of mass energy near the horizon(s) of an extremal and non-extremal Kerr-Newman-Taub-NUT black hole and show that an arbitrarily high center of mass energy is achievable under some restrictions. We will study the special case of the center of mass energy when the specific energy, specific angular momentum and Carter constant of both the particles are same.Comment: 23 pages, 7 figures, 2 tables, Accepted in JHE

Brand democratization and customer brand engagement: understanding the customer-brand power distance

Tese de doutoramento em Marketing and StrategyMarcas de luxo, anteriormente acessíveis à elite da sociedade estão agora a ser comercializadas para um segmento maior do mercado, isto pode ser atribuído principalmente ao processo de democratização da marca (DB). No entanto, no context académico há uma falta de escrutínio sobre a influência da democratização da marca de luxo e o seu impacto no envolvimento do cliente em relação à marca. Para explorar os pressupostos sublinhados da democratização da marca e do envolvimento do cliente-marca, desenvolveu-se um modelo conceptual baseado na literatura proporcionando um entendimento mais profundo da democratização da marca. Utilizando uma metodologia predominantemente quantitativa de recolha de dados, esta pesquisa explora os pressupostos subjacentes a uma marca de luxo mais democrática, conduzindo três estudos. O estudo 1 explora o construto da democratização da marca através de uma revisão sistemática da literatura e identificando várias dimensões que apoiam uma melhor compreensão do conceito. O estudo 2 desenvolve uma escala de democratização da marca baseada na acessibilidade e comunicação, enquanto o estudo 3 testa a relação entre a democratização da marca e o envolvimento do cliente com a marca (ECM). Os resultados revelam o impacto positivo da democratização da marca no envolvimento do cliente com a marca, apelando assim a mais investigação sobre o impacto mediador das interacções cliente-marca. O controlo e o empowerment que os consumidores/clientes de marcas de luxo desejam exercer sobre as marcas foram considerados como moderadores sobre a relação entre DB e ECM. Globalmente, os resultados confirmam as hipóteses, revelando que variáveis como o "eu ideal", a auto-congruência com a marca e o prestígio em massa, têm um impacto positivo na democratização da marca. Este estudo empírico sobre a democratização da marca apresenta vários avanços teóricos e visa ajudar as marcas de luxo a desenvolver uma estratégia coerente a longo prazo para gerir desafios únicos.Luxury brands which were once accessible to the elite of the society are now being marketed to a larger segment of the market, this can be mainly attributed to the process of brand democratization (BD). However much academic scrutiny on the influence of democratization and its consequent impact on customer brand engagement is lacking. To explore the underlined assumptions of brand democratization and customer-brand engagement preliminary conceptual model and the existing literature, advocates for a deeper understanding into brand democratization. Using pre-dominantly quantitative methods of data collection, this research explores the underlying assumptions of a more democratic brand by simultaneously conducting three studies, study one primarily explored brand democratization through a systematic review of the literature and identified several dimensions which support a better understanding of the construct. Study 2 helped develop brand democratization scale based on accessibility and communication while study 3 tested and confirmed the relationship between brand democratization and customer brand engagement (CBE). The results revealed positive impact of brand democratization on customer brand engagement thus calling for further investigations on the mediating impact of customer-brand interactions. The control and empowerment that luxury brand consumers/customers wish to exert on brands were taken into consideration while study for the moderating impact on the relationship between BD and CBE. Overall, the results were favourable to the hypothesized statements, revealing that predictors such as ideal-self, self-congruity with the brand and mass-prestige to have positive impact on brand democratization This academic empirical exploration on brand democratization therefore provides several theoretical advancements and aims to assist luxury brands in developing a coherent long-term strategy to manage unique challenges

Learning relevant eye movement feature spaces across users

In this paper we predict the relevance of images based on a lowdimensional feature space found using several users’ eye movements. Each user is given an image-based search task, during which their eye movements are extracted using a Tobii eye tracker. The users also provide us with explicit feedback regarding the relevance of images. We demonstrate that by using a greedy Nystrom algorithm on the eye movement features of different users, we can find a suitable low-dimensional feature space for learning. We validate the suitability of this feature space by projecting the eye movement features of a new user into this space, training an online learning algorithm using these features, and showing that the number of mistakes (regret over time) made in predicting relevant images is lower than when using the original eye movement features. We also plot Recall-Precision and ROC curves, and use a sign test to verify the statistical significance of our results

Embedded Speech Technology

openEnd-to-End models in Automatic Speech Recognition simplify the speech recognition process. They convert audio data directly into text representation without exploiting multiple stages and systems. This direct approach is efficient and reduces potential points of error. On the contrary, Sequence-to-Sequence models adopt a more integrative approach where they use distinct models for retrieving the acoustic and language-specific features, which are respectively known as acoustic and language models. This integration allows for better coordination between different speech aspects, potentially leading to more accurate transcriptions. In this thesis, we explore various Speech-to-Text (STT) models, mainly focusing on End-to-End and Sequence-to-Sequence techniques. We also look into using offline STT tools such as Wav2Vec2.0, Kaldi and Vosk. These tools face challenges when handling new voice data or various accents of the same language. To address this challenge, we fine-tune the models to make them better at handling new, unseen data. Through our comparison, Wav2Vec2.0 emerged as the top performer, though with a larger model size. Our approach also proves that using Kaldi and Vosk together creates a robust STT system that can identify new words using phonemes

Development of synchronverter control for induction motor connection

More and more attention has been paid to the energy crisis due to the increasing energy demand from industrial and commercial applications. The utilization of renewable energy considered as one of the most promising electrical energy sources, which has grown rapidly in the last three decades. In this day and age, many power converter techniques have been developed to integrate renewable energy with the electrical grid. In this work, there is a new technical control is known as synchronverter control which is using the synchronous generator mathematical equations as a reference. This synchronverter control is connected with DC-AC three phase inverter to work as controller of output power to feed the load. In this control strategy, the output current of the controllable inverter is controlled by a feedback load current according to the current reference. The synchronverter technology has been applied to control the inverter for the induction motor connection. An experimental setup based on DSP (Digital Signal Processing) and dc drive board have been designed to implement the open and closed loop experiments. All experiments have been implemented on a test rig based on Matlab 20013a/simulink software and Code Composer Studio V6.0 to demonstrate the excellent performance of the proposed control strategies with stability of the system, sinusoidal currents and good dynamics. Finally, an improve control strategy based on the synchronverter control technology has been tested for three phase inverter for renewable energy applications to make the whole system behave as a synchronous generator