Optical Microresonator-Based Flow-Speed Sensor

Optical sensors have become more prominent in atmospheric measurement systems, with LiDAR instruments deployed on a variety of earth-bound, air-borne, and space-based platforms. In recent years, the interest in the human exploration of Mars has created a substantial push towards reliable and compact sensing elements for Mars exploration missions, particularly during a spacecraft’s entry, descent, and landing stages. Real-time sensors able to reliably measure the craft’s speed relative to the surrounding atmosphere during these stages are thus of great interest. In this dissertation, a proof-of-concept for an optical microfabricated sensor, which leverages the whispering-gallery-mode (WGM) and Doppler shift principles, is developed to measure wind speed from atmospheric particles through light scattering. WGM micro-resonators could replace Fabry–Perot interferometers and other optical frequency discriminators often employed in remote sensing applications, thereby significantly reducing the size and weight of the measurement system. The capabilities of the presented sensor concept are first studied under the aerosol scattering regime, and the measurement resolution of the WGM resonators is assessed. An optical system is developed, and velocity measurements near the exit of a seeded air jet nozzle are carried out to validate the velocity measurement capabilities from aerosol streams. The feasibility of employing WGM resonators for molecular scattering-based measurements of atmospheric properties is also investigated. A modified mathematical model for coherent and spontaneous scattering is implemented in the performance analyses of the resonators for different altitudes of Earth and Mars atmospheres. Spectral profiles generated from the model are compared to those in the literature under similar conditions. An analysis for photon count under various atmospheric conditions and altitudes is also carried out. The analyses indicate that WGM resonator-based spectral instruments may be viable as part of future compact and lightweight atmospheric sensors

C-FLAT: Control-FLow ATtestation for Embedded Systems Software

Remote attestation is a crucial security service particularly relevant to increasingly popular IoT (and other embedded) devices. It allows a trusted party (verifier) to learn the state of a remote, and potentially malware-infected, device (prover). Most existing approaches are static in nature and only check whether benign software is initially loaded on the prover. However, they are vulnerable to run-time attacks that hijack the application's control or data flow, e.g., via return-oriented programming or data-oriented exploits. As a concrete step towards more comprehensive run-time remote attestation, we present the design and implementation of Control- FLow ATtestation (C-FLAT) that enables remote attestation of an application's control-flow path, without requiring the source code. We describe a full prototype implementation of C-FLAT on Raspberry Pi using its ARM TrustZone hardware security extensions. We evaluate C-FLAT's performance using a real-world embedded (cyber-physical) application, and demonstrate its efficacy against control-flow hijacking attacks.Comment: Extended version of article to appear in CCS '16 Proceedings of the 23rd ACM Conference on Computer and Communications Securit

Resource-aware IoT Control: Saving Communication through Predictive Triggering

The Internet of Things (IoT) interconnects multiple physical devices in large-scale networks. When the 'things' coordinate decisions and act collectively on shared information, feedback is introduced between them. Multiple feedback loops are thus closed over a shared, general-purpose network. Traditional feedback control is unsuitable for design of IoT control because it relies on high-rate periodic communication and is ignorant of the shared network resource. Therefore, recent event-based estimation methods are applied herein for resource-aware IoT control allowing agents to decide online whether communication with other agents is needed, or not. While this can reduce network traffic significantly, a severe limitation of typical event-based approaches is the need for instantaneous triggering decisions that leave no time to reallocate freed resources (e.g., communication slots), which hence remain unused. To address this problem, novel predictive and self triggering protocols are proposed herein. From a unified Bayesian decision framework, two schemes are developed: self triggers that predict, at the current triggering instant, the next one; and predictive triggers that check at every time step, whether communication will be needed at a given prediction horizon. The suitability of these triggers for feedback control is demonstrated in hardware experiments on a cart-pole, and scalability is discussed with a multi-vehicle simulation.Comment: 16 pages, 15 figures, accepted article to appear in IEEE Internet of Things Journal. arXiv admin note: text overlap with arXiv:1609.0753

Applications notice

The discipline programs of the Space and Terrestrial (S&T) Applications Program are described and examples of research areas of current interest are given. Application of space techniques to improve conditions on earth are summarized. Discipline programs discussed include: resource observations; environmental observations; communications; materials processing in space; and applications systems/information systems. Format information on submission of unsolicited proposals for research related to the S&T Applications Program are given

Introducing a new technology to enhance community sustainability: An investigation of the possibilities of sun spots

The introduction of the Sun SPOT, Small Programmable Object Technology, developed by Sun Microsystems has been depicted as providing a revolutionary change in cyber physical interaction. Based on Sun Java Micro Edition (ME), this sensor technology has the potential to be used across a number of discipline areas to interface with systems, the environment and biological domains. This paper will outline the potential of Sun SPOTs to enhance community sustainability. An action based research project was carried out to investigate the potential uses of these technologies and develop a prototype system as a proof of concept. The research will compare Sun SPOTs with similar technologies, provide an assessment of the technology, and propose a number of possible implementations of the technology to enhance community sustainability

Data Requirements for Oceanic Processes in the Open Ocean, Coastal Zone, and Cryosphere

The type of information system that is needed to meet the requirements of ocean, coastal, and polar region users was examined. The requisite qualities of the system are: (1) availability, (2) accessibility, (3) responsiveness, (4) utility, (5) continuity, and (6) NASA participation. The system would not displace existing capabilities, but would have to integrate and expand the capabilities of existing systems and resolve the deficiencies that currently exist in producer-to-user information delivery options

Intelligent distributed multimedia collection: content aggregation and integration

People's multimedia content is spread around their home network and content services on the Internet, such as YouTube, Flickr, Facebook. In this paper we present a system that aggregates all the multimedia content of the end user and integrates it into a unified collection for the user's convenience. The system provides location transparency of multimedia content, content filtering on player compatibility and metadata completion to aid in improved usability. This effectively enables the user to rediscover his multimedia collection without any technical knowledge. A proof-of-concept implementation known as Intelligent Distributed Multimedia Collection (IDMC) has been made that is able to detect and browse UPnP MediaServer devices as well as collect information from YouTube. This implementation also contains a media player and is able to control UPnP MediaRenderer devices remotely. Furthermore, performance has been measured to assess different ways of iterating through a multimedia collection