DolphinAtack: Inaudible Voice Commands

Speech recognition (SR) systems such as Siri or Google Now have become an increasingly popular human-computer interaction method, and have turned various systems into voice controllable systems(VCS). Prior work on attacking VCS shows that the hidden voice commands that are incomprehensible to people can control the systems. Hidden voice commands, though hidden, are nonetheless audible. In this work, we design a completely inaudible attack, DolphinAttack, that modulates voice commands on ultrasonic carriers (e.g., f > 20 kHz) to achieve inaudibility. By leveraging the nonlinearity of the microphone circuits, the modulated low frequency audio commands can be successfully demodulated, recovered, and more importantly interpreted by the speech recognition systems. We validate DolphinAttack on popular speech recognition systems, including Siri, Google Now, Samsung S Voice, Huawei HiVoice, Cortana and Alexa. By injecting a sequence of inaudible voice commands, we show a few proof-of-concept attacks, which include activating Siri to initiate a FaceTime call on iPhone, activating Google Now to switch the phone to the airplane mode, and even manipulating the navigation system in an Audi automobile. We propose hardware and software defense solutions. We validate that it is feasible to detect DolphinAttack by classifying the audios using supported vector machine (SVM), and suggest to re-design voice controllable systems to be resilient to inaudible voice command attacks.Comment: 15 pages, 17 figure

Cost-Effective and Energy-Efficient Techniques for Underwater Acoustic Communication Modems

Finally, the modem developed has been tested experimentally in laboratory (aquatic environment) showing that can communicates at different data rates (100..1200 bps) compared to state-of-the-art research modems. The software used include LabVIEW, MATLAB, Simulink, and Multisim (to test the electronic circuit built) has been employed.Underwater wireless sensor networks (UWSNs) are widely used in many applications related to ecosystem monitoring, and many more fields. Due to the absorption of electromagnetic waves in water and line-of-sight communication of optical waves, acoustic waves are the most suitable medium of communication in underwater environments. Underwater acoustic modem (UAM) is responsible for the transmission and reception of acoustic signals in an aquatic channel. Commercial modems may communicate at longer distances with reliability, but they are expensive and less power efficient. Research modems are designed by using a digital-signal-processor (DSP is expensive) and field-programmable-gate-array (FPGA is high power consuming device). In addition to, the use of a microcontroller is also a common practice (which is less expensive) but provides limited computational power. Hence, there is a need for a cost-effective and energy-efficient UAM to be used in budget limited applications. In this thesis different objectives are proposed. First, to identify the limitations of state-of-the-art commercial and research UAMs through a comprehensive survey. The second contribution has been the design of a low-cost acoustic modem for short-range underwater communications by using a single board computer (Raspberry-Pi), and a microcontroller (Atmega328P). The modulator, demodulator and amplifiers are designed with discrete components to reduce the overall cost. The third contribution is to design a web based underwater acoustic communication testbed along with a simulation platform (with underwater channel and sound propagation models), for testing modems. The fourth contribution is to integrate in a single module two important modules present in UAMs: the PSK modulator and the power amplifier

A survey of new technology for cockpit application to 1990's transport aircraft simulators

Two problems were investigated: inter-equipment data transfer, both on board the aircraft and between air and ground; and crew equipment communication via the cockpit displays and controls. Inter-equipment data transfer is discussed in terms of data bus and data link requirements. Crew equipment communication is discussed regarding the availability of CRT display systems for use in research simulators to represent flat panel displays of the future, and of software controllable touch panels

The design of micro-processors for digital protection of power systems

Imperial Users onl

Data systems elements technology assessment and system specifications, issue no. 2

The ability to satisfy the objectives of future NASA Office of Applications programs is dependent on technology advances in a number of areas of data systems. The hardware and software technology of end-to-end systems (data processing elements through ground processing, dissemination, and presentation) are examined in terms of state of the art, trends, and projected developments in the 1980 to 1985 timeframe. Capability is considered in terms of elements that are either commercially available or that can be implemented from commercially available components with minimal development

Development of a low-cost robotic squirrel for the study of small animal behavior

This project focuses on building a low-cost remote controlled Robot Squirrel to support the study of small animal behavior. It can also be implemented as an educational tool for all the stages of the educational systems, from elementary to university level. It is a ground-based motion robot, which is driven at variable speeds utilizing slip steering (a method similar to the motion of a tank) which can be moved in any desired direction. It supports an on-board video system to record, and monitor various behavioral patterns of animals, primarily squirrels in this project even from a distance. It also comprises of an audio system which can record and playback sounds to the animals and a simple robot arm-like structure with two degree of freedom controlled by servos, which acts as a nut delivery system to the animals. An Android smart phone application was developed to control the motion and speed of the robot and other operational controls in the system, like record and playback control and also the movement of the robot arm. Arduino Uno, an ATmega328 based microcontroller board acts as the major control unit of the entire system. A Bluetooth module acts as an interface between the Arduino and the smart phone supporting the control and operation of the Robotic Squirrel

Earth Observatory Satellite system definition study. Report 3: Design cost trade-off studies and recommendations

An analysis of the design and cost tradeoff aspects of the Earth Observatory Satellite (EOS) development is presented. The design/cost factors that affect a series of mission/system level concepts are discussed. The subjects considered are as follows: (1) spacecraft subsystem cost tradeoffs, (2) ground system cost tradeoffs, and (3) program cost summary. Tables of data are provided to summarize the results of the analyses. Illustrations of the various spacecraft configurations are included

Reefer container monitoring system based on WSN and cloud technology

Reefer containers are the main transportation method for the import and export of food and medicine. For high-quality products is necessary to monitor the condition of the reefer containers in order to avoid affecting goods quality due to environmental variations. Monitoring the reefer containers which are used to transport fruits, vegetables, and dairy products is one of the examples. In this context appears the necessity to develop this work expressed by a distributed sensor system for monitoring reefer containers. With the support of the WSN (wireless sensor network) including a set of sensors, it is possible to obtain the information about the temperature, humidity and location data of the reefer container and upload those data to a cloud platform expressed in the case of the purposed system by The Things Network platform. Based on LEACH (Low Energy Adaptive Clustering Hierarchy) routing algorithm, the embedded software was developed to guarantee a well-balanced distribution of the energy load among WSN end-nodes. A web application and a mobile application has been developed to display the data coming from the WSN node. To check if the reefer container working in a good condition, an alarm software module has been developed to highlight abnormal data coming for the system. The routing algorithm has been simulated and the effectiveness of the algorithm is verified by simulation results. The effectiveness of the proposed system was experimentally tested, and several results are included in this dissertation.Os contentores frigoríficos são o principal método de transporte para a importação e exportação de alimentos e medicamentos. Em produtos de alta qualidade, é necessário monitorizar as condições dos contentores frigoríficos, a fim de evitar a perda da qualidade das merca dorias devido a variações térmicas. Por exemplo, monitorarizando os contentores frigoríficos usados para transportar frutas, vegetais e laticínios. Neste contexto, aparece a necessidade do desenvolvimento deste projeto descrito por um sistema de sensores distribuídos para monitorizar contentores frigoríficos. Com o suporte da rede de sensores sem fios, incluindo um conjunto de sensores, é possível obter informações sobre os dados da temperatura, humidade e localização do contentor refrigerado e fazer uplo ad desses dados numa plataforma em cloud expressa no caso do sistema proposto por plataforma de rede de coisas. Com base no algoritmo de roteamento LEACH, o software incorporado foi desenvolvido para garantir uma distribuição equilibrada da carga de energi a entre os nós de WSN. Uma aplicação Web e uma aplicação móvel foram desenvolvidas para mostrar os dados provenientes do nó WSN. Para verificar a qualidade dos dados, um módulo de software de alarme foi também desenvolvido para destacar dados anormais que chegam ao sistema. O algoritmo de roteamento foi simulado e a eficiência do algoritmo é verificada pelos resultados da simulação. A eficiência do sistema proposto foi testada experimentalmente e os vários resultados estão incluídos nesta dissertação