Research of North Pole amphibious vehicle's technologies and Powertrain simulation

The aim of this master’s thesis is to provide a useful framework for upcoming researches about amphibious vehicles designed for the North Pole. This thesis is a brief introduction to the North Pole Amphibious Vehicles, which consists in studying the main requirements of this kind of vehicle. Thus, the research about amphibious vehicle technologies is done on the state-of-art and different powertrain systems and configurations are studied. In this project, a 3D design of an amphibious vehicle and its flow simulation were created with Solidworks in order to calculate the longitudinal parameters of the vehicle. The powertrain system has been chosen following an analysis of conventional, electric and hybrid powertrains, so as to determine which system has a better performance at the North Pole. Different powertrain configurations have been modelled in Matlab Simulink following the mathematical equations that describe the components or using the Powertrain Blockset offered by Matlab. The software simulates the whole powertrain dynamics in conjunction. The results obtained by the simulation were used to compare the 4WD and 6WD powertrains in order to find out which are the most suitable.Outgoin

Diseño de un extrusor para imprimir chocolate

El presente trabajo trata sobre el diseño de un extrusor de impresora 3D capaz de imprimir chocolate que inicialmente se encuentra en estado sólido. Se ha realizado un estado del arte para estudiar este tipo de producto en el mercado actual, conocer sus carencias y saber que es necesario mejorar. También se ha estudiado las propiedades reológicas del chocolate para conocer cómo y que es necesario para tratar con este material. Conocido los requisitos para derretir chocolate, se ha realizado el diseño siguiendo diversas normativas de construcción de máquinas alimentarias, es decir, se ha realizado un diseño higiénico y se ha seleccionado los materiales de cada componente del extrusor para que pudieran entrar en contacto con material alimentario. También se han limitado las dimensiones para que fuera adaptable con las impresoras 3D actuales del mercado. Finalmente con el diseño terminado, se verifica la capacidad calefactora y la capacidad de extrusión del extrusor con los componentes elegidos

Rupture evolution of the 2006 Java tsunami earthquake and the possible role of splay faults

Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Tectonophysics 721 (2017): 143-150, doi:10.1016/j.tecto.2017.10.003.The 2006 Mw 7.8 Java earthquake was a tsunami earthquake, exhibiting frequency-dependent seismic radiation along strike. High-frequency global back-projection results suggest two distinct rupture stages. The first stage lasted ~65 s with a rupture speed of ~1.2 km/s, while the second stage lasted from ~65 to 150 s with a rupture speed of ~2.7 km/s. High-frequency radiators resolved with back-projection during the second stage spatially correlate with splay fault traces mapped from residual free-air gravity anomalies. These splay faults also colocate with a major tsunami source associated with the earthquake inferred from tsunami first-crest back-propagation simulation. These correlations suggest that the splay faults may have been reactivated during the Java earthquake, as has been proposed for other tsunamigenic earthquakes, such as the 1944 Mw 8.1 Tonankai earthquake in the Nankai Trough.W.F. is currently supported by the Postdoctoral Scholar Program at the Woods Hole Oceanographic Institution, with funding provided by the Weston Howland Jr. Postdoctoral Scholarship

Inaudible Adversarial Perturbation: Manipulating the Recognition of User Speech in Real Time

Automatic speech recognition (ASR) systems have been shown to be vulnerable to adversarial examples (AEs). Recent success all assumes that users will not notice or disrupt the attack process despite the existence of music/noise-like sounds and spontaneous responses from voice assistants. Nonetheless, in practical user-present scenarios, user awareness may nullify existing attack attempts that launch unexpected sounds or ASR usage. In this paper, we seek to bridge the gap in existing research and extend the attack to user-present scenarios. We propose VRIFLE, an inaudible adversarial perturbation (IAP) attack via ultrasound delivery that can manipulate ASRs as a user speaks. The inherent differences between audible sounds and ultrasounds make IAP delivery face unprecedented challenges such as distortion, noise, and instability. In this regard, we design a novel ultrasonic transformation model to enhance the crafted perturbation to be physically effective and even survive long-distance delivery. We further enable VRIFLE's robustness by adopting a series of augmentation on user and real-world variations during the generation process. In this way, VRIFLE features an effective real-time manipulation of the ASR output from different distances and under any speech of users, with an alter-and-mute strategy that suppresses the impact of user disruption. Our extensive experiments in both digital and physical worlds verify VRIFLE's effectiveness under various configurations, robustness against six kinds of defenses, and universality in a targeted manner. We also show that VRIFLE can be delivered with a portable attack device and even everyday-life loudspeakers.Comment: Accepted by NDSS Symposium 202

Enrollment-stage Backdoor Attacks on Speaker Recognition Systems via Adversarial Ultrasound

Automatic Speaker Recognition Systems (SRSs) have been widely used in voice applications for personal identification and access control. A typical SRS consists of three stages, i.e., training, enrollment, and recognition. Previous work has revealed that SRSs can be bypassed by backdoor attacks at the training stage or by adversarial example attacks at the recognition stage. In this paper, we propose TUNER, a new type of backdoor attack against the enrollment stage of SRS via adversarial ultrasound modulation, which is inaudible, synchronization-free, content-independent, and black-box. Our key idea is to first inject the backdoor into the SRS with modulated ultrasound when a legitimate user initiates the enrollment, and afterward, the polluted SRS will grant access to both the legitimate user and the adversary with high confidence. Our attack faces a major challenge of unpredictable user articulation at the enrollment stage. To overcome this challenge, we generate the ultrasonic backdoor by augmenting the optimization process with random speech content, vocalizing time, and volume of the user. Furthermore, to achieve real-world robustness, we improve the ultrasonic signal over traditional methods using sparse frequency points, pre-compensation, and single-sideband (SSB) modulation. We extensively evaluate TUNER on two common datasets and seven representative SRS models. Results show that our attack can successfully bypass speaker recognition systems while remaining robust to various speakers, speech content, e

Diseño de un extrusor para imprimir chocolate

El presente trabajo trata sobre el diseño de un extrusor de impresora 3D capaz de imprimir chocolate que inicialmente se encuentra en estado sólido. Se ha realizado un estado del arte para estudiar este tipo de producto en el mercado actual, conocer sus carencias y saber que es necesario mejorar. También se ha estudiado las propiedades reológicas del chocolate para conocer cómo y que es necesario para tratar con este material. Conocido los requisitos para derretir chocolate, se ha realizado el diseño siguiendo diversas normativas de construcción de máquinas alimentarias, es decir, se ha realizado un diseño higiénico y se ha seleccionado los materiales de cada componente del extrusor para que pudieran entrar en contacto con material alimentario. También se han limitado las dimensiones para que fuera adaptable con las impresoras 3D actuales del mercado. Finalmente con el diseño terminado, se verifica la capacidad calefactora y la capacidad de extrusión del extrusor con los componentes elegidos

Research of North Pole amphibious vehicle's technologies and Powertrain simulation

The aim of this master’s thesis is to provide a useful framework for upcoming researches about amphibious vehicles designed for the North Pole. This thesis is a brief introduction to the North Pole Amphibious Vehicles, which consists in studying the main requirements of this kind of vehicle. Thus, the research about amphibious vehicle technologies is done on the state-of-art and different powertrain systems and configurations are studied. In this project, a 3D design of an amphibious vehicle and its flow simulation were created with Solidworks in order to calculate the longitudinal parameters of the vehicle. The powertrain system has been chosen following an analysis of conventional, electric and hybrid powertrains, so as to determine which system has a better performance at the North Pole. Different powertrain configurations have been modelled in Matlab Simulink following the mathematical equations that describe the components or using the Powertrain Blockset offered by Matlab. The software simulates the whole powertrain dynamics in conjunction. The results obtained by the simulation were used to compare the 4WD and 6WD powertrains in order to find out which are the most suitable.Outgoin

Diseño de un extrusor para imprimir chocolate

El presente trabajo trata sobre el diseño de un extrusor de impresora 3D capaz de imprimir chocolate que inicialmente se encuentra en estado sólido. Se ha realizado un estado del arte para estudiar este tipo de producto en el mercado actual, conocer sus carencias y saber que es necesario mejorar. También se ha estudiado las propiedades reológicas del chocolate para conocer cómo y que es necesario para tratar con este material. Conocido los requisitos para derretir chocolate, se ha realizado el diseño siguiendo diversas normativas de construcción de máquinas alimentarias, es decir, se ha realizado un diseño higiénico y se ha seleccionado los materiales de cada componente del extrusor para que pudieran entrar en contacto con material alimentario. También se han limitado las dimensiones para que fuera adaptable con las impresoras 3D actuales del mercado. Finalmente con el diseño terminado, se verifica la capacidad calefactora y la capacidad de extrusión del extrusor con los componentes elegidos