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Modern embedded systems---autonomous vehicle-to-vehicle communication, smart cities, and military Joint All-Domain Operations---feature increasingly heterogeneous distributed components. As a result, existing communication methods, tightly coupled with specific networking layers and individual applications, can no longer balance the flexibility of modern data distribution with the traditional constraints of embedded systems. To address this problem, the investigation herein presents a domain-specific language, designed around the Representational State Transfer (REST) architecture, most famously used on the web. Our language, called the Communication Language for Embedded Systems (CLES), supports both traditional point-to-point data communication and management and allocation of decentralized distributed processing tasks. To meet the traditional constraints of embedded execution, CLES' novel runtime allocates processing tasks across a heterogeneous network of embedded devices, overcoming limitations from other modern distribution methods: centralized task management and limited operating system integration. CLES was evaluated with performance micro-benchmarks, implementation of distributed stochastic gradient descent, and application to the design of versatile stateless services for vehicle-to-vehicle communication and military Joint All-Domain Command and Control (JDAC). From this evaluation, it was determined that CLES meets the data distribution needs of realistic cyber-physical embedded systems. / Master of Science / As computers become smaller, cheaper, more powerful, and energy efficient, they are increasingly used in cyber-physical systems such as planes, trains, and automobiles, as well as large-scale networks such as power plants and smart cities. The field of embedded computing is facing new challenges involving the communication and coordination of large numbers of different devices. Some of the software challenges within embedded device communications are: flexibility both in ability to run on different devices and use different communication links such as cellular, Wi-Fi, or Bluetooth, performance constraints of low-power embedded devices, latency and reliability to ensure safe operations, and the schedule and cost of development. To address these challenges, this thesis presents a new programming language, designed around the Representational State Transfer (REST) architecture, most famously used in HTTP to drive the web. Our language, called the Communication Language for Embedded Systems (CLES), supports both traditional point-to-point data communication designed to prioritize latency and reliability, as well as a standalone application or runtime that can be run on an embedded device to accept requests for processing tasks. CLES and its supporting Software Development Kit (SDK) is designed to allow for quick and cost effective development of flexible low-latency device to device communications and large scale distributed processing on embedded devices.

Gas Chromatography (GC) is one of the most important and widely used tools in analytical chemistry. However, they are bulky, have a longer measurement cycle, and consume a high amount of power. Micro-Gas Chromatography (µGC) is portable and energy-efficient, which allows onsite, real-time biological, forensic, and environmental analyses. This thesis presents a ready-to-deploy implementation of microfabricated gas chromatography (µGC) system capable of separating complex samples. We describe robust, modular, and scalable hardware and software architecture based on Real-Time Operating System (RTOS) and Python Graphical User Interface (GUI) integrated with various microfabricated devices to realize a fully functional µGC system. A sample heater for headspace injection, microfabricated separation column (µSC), a Photoionization Detector (PI-D), and a flow controller unit are integrated with the modular hardware and software to realize a fully functional Vacuum Outlet µGC system. We have designed a novel auto-calibration method for temperature calibration of the microfabricated devices which does not require changing the electronic circuitry or reprogramming the device. The vacuum outlet µGC setup is tested with various mixture of analytes. For these experiments, an average relative standard deviation (RSD) for retention time repeatability of 2.5% is achieved. Data processing techniques for raw chromatograms, including baseline correction and peak detection, are implemented on a microcontroller board and tested extensively as a part of this work. A novel algorithm for multidimensional analysis for the identification of co-eluting compounds in complex samples is implemented with a prediction accuracy of 94%. / Master of Science / Toxic volatile organic compounds (VOCs) such as benzene and toluene found in gasoline and xylene used in ink, rubber, and leather industries are of concern as they are present at elevated concentrations due to their higher vapor pressure. Sufficient exposure to these toxicants, even at lower concentrations like 100 parts-per-billion-volume (ppbv), may cause adverse health effects. Gas Chromatography (GC) has been the established method for assessing the presence and concentration of VOCs in the environment. Traditional GC systems are bulky, power-hungry, expensive, and require expert supervision for analysis. Recent research in microelectromechanical systems (MEMS) has reduced the size of the GC components, also called micro-GC (µGC), while improving the performance. The majority of the research and development of µGC is aimed at advancing microfabricated components such as preconcentrators, separation columns, and gas detectors. However, the integration of these different components is an important topic that requires more investigation. In this thesis, we present a robust and scalable software and hardware architecture that can be used to develop a portable and modular µGC system. The thesis discusses different experiments to calibrate various microfabricated devices, which are then used to build a fully modular µGC system. We show the separation capacity of the modular µGC system by passing complex compounds like kerosene and diesel. As the chromatogram from the µGC system has noise, the second part of the thesis explores data analysis techniques such as baseline correction, peak detection. These data analysis tools are used to filter the noise, detect relevant peaks in the chromatograms, and identify the compounds in a complex sample.

Technological advances are providing us with the capability to integrate more and more functionality into a single chip. This is leading to a new design paradigm, System On a Chip (SOC). In SOC designs all the functionality of a system is put inside a single chip, leading to increased performance, reduced power consumption, lower costs, and reduced size. SOC design brings with it new challenges and difficulties, however. The designs are now large, complicated and involve both software and hardware components. The designs have to be modeled at a high level of abstraction before partitioning into hardware and software components for final implementation. SystemC is a system level modeling language useful for System On a Chip design. It provides various features to perform system level modeling and simulation, which are missing in the generic HDL's such as VHDL and Verilog. The hardware portion of the SystemC models can be synthesized into hardware using commercial tools . The software portion can be rewritten as embedded software for the target processor. The aim of this thesis is to explore the SOC design process and to define methods for software synthesis of SystemC models. Software synthesis involves translation of SystemC models into code that is suitable for execution on an embedded processor. A simple scheduler that replaces the SystemC simulation kernel is proposed. This scheduler allows SystemC models to be executed directly as embedded software without the need for extensive modification or translation. Application of this process to the development of a GSM speech processing system, including the translation of part of the SystemC model into software that will execute on an embedded processor, is shown and the results are presented. / Master of Science

As Cyber Physical Systems (CPS) are getting more complex and safety critical, Model Based Design (MBD), which consists of building formal models of a system in order to be used in verification and correct-by-construction code generation, is becoming a promising methodology for the development of the embedded software of such systems. This design paradigm significantly reduces the development cost and time while guaranteeing better robustness, capability and correctness with respect to the original specifications, when compared with the traditional ad-hoc design methods. SIMULINK has been the most popular tool for embedded control design in research as well as in industry, for the last decades. As SIMULINK does not have formal semantics, the application of the model based design methodology and tools to its models is very limited. In this thesis, we present a semantic translator that transform discrete time SIMULINK models into SIGNAL programs. The choice of SIGNAL is motivated by its polychronous formalism that enhances synchronous programming with asynchronous concurrency, as well as, by the ability of its compiler of generating deterministic multi thread code. Our translation involves three major steps: clock inference, type inference and hierarchical top-down translation. We validate the semantic preservation of our prototype tool by testing it on different SIMULINK models. / Master of Science

A ready-to-deploy implementation of microfabricated gas chromatography (microGC) system characterized for detecting hazardous air pollutants (HAPs) at parts-per-billion (ppb) concentrations in complex mixtures has been described. A microfabricated preconcentrator (microPC), a MEMS separation column with on-chip thermal conductivity detector (microSC-TCD), the flow controller unit, and all the necessary flow and thermal management as well as user interface circuitry are integrated to realize the fully functional microGC system. The work reports extensive characterization of microPC, microSC and micro]TCD for target analytes: benzene, toluene, tetrachloroethylene, chlorobenzene, ethylbenzene, and p-xylene. Limit of Detection (LOD) of ~1 ng was achieved, which corresponds to 10 min sampling time at a flow rate of 1 mL/min for analyte present at ~25 ppbv concentration. An innovative method for generating very sharp injection plugs from the microPC even in the presence of flow sensitive detectors like micro]TCD is described. A one-to-one comparison between microGC system and conventional Automated Thermal Desorption-Gas Chromatograph-Flame Ionization Detector (ATD GC-FID) system for real gasoline samples in simulated car refueling scenario is reported. / Master of Science

This thesis presents the design and implementation of a transparent messaging protocol for distributed communication between processors. The processors are designed using dataflow architecture. The protocol ensures transparent asynchronous communication between distributed processes. The protocol is designed such that an application can run without change in virtually any kind of distributed configuration, where configuration is the number of controllers used in the system plus the processor allocation strategy used. It also enables an automated processor allocation strategy to transparently configure an application for any number of processor nodes without requiring any changes or recompilation. The protocol works well even for single-controller applications and for a pre-defined allocation of processors to controllers. The thesis further includes an analysis of the time required for one complete cycle of inter-processor communication. / Master of Science

Embedded sensors are a fixture of most devices in the current computer industry. These small devices are used for a variety of purposes throughout many fields to collect whatever kind of information is needed by the user. From data on device acceleration to data on position relative to the Earth's magnetic field, embedded sensors can provide it for any number of tasks. The advent of these devices has made work and research in the computer industry significantly easier but they are not without their drawbacks. Most of these sensors operate by drawing external data from the environment through send and receive signals. This mode of operation leaves them vulnerable to external malicious users who seek access to the data being stored and handled by the sensors. Concerns over security and privacy of embedded sensor data has become a topic of great concern with the continued digitization of sensitive personal data. Within the last five years, studies have shown the ability to manipulate embedded magnetic sensors in order to gain access to various forms of sensitive personal data. This is of great concern to the developers of mobile devices as most mobile devices possess embedded magnetic sensors. The vulnerability of sensors to external influence leads to concerns for both data privacy and degradation of public trust in the ability of their devices to keep their personal information safe and out of the wrong hands. Degradation of public trust in security methodologies is a major concern to many in the research and tech industry as much of the work conducted to advance both security and technology depends on large amounts of public data. If the public loses trust in the ability of the devices used by researchers to protect and ensure the safety of the data provided to them, then they may stop providing data which would then make the work of researchers and other tech workers considerably more difficult. To address these concerns, this thesis will present an introduction to Magnetic sensor devices (a prominent tool for data collection), how these sensors work and the ways they handle data. We shall then examine the techniques used to interfere with the functioning and output of magnetic sensors employed by mobile devices. Finally, we shall examine existing techniques for defending against these kinds of attacks as well as propose potential new techniques. The end goal of this work is to provide a broader perspective on the nature of environmental/natural interference and its relationship to scientific study and technological advancement. Literature around this topic does exist, however, all existing works currently in the literature focus exclusively on one form of interference i.e., light which leads to a smaller/narrower perspective which this work seeks to remedy. The end result is meant to give a broader perspective of multiple forms of interference and their interrelations between each other than is possible by current perspectives due to their narrow lens. / Master of Science / Embedded sensors are small devices integrated into many mobile devices currently in the public market. These devices serve to collect environmental data of all kinds in order to perform a variety of functions. From directional calibration to magnetic orientation in relation to the magnetic north pole, sensors perform it all. This has led to a massive increase in computer power and quality of life for the general public but not without issue. The increase in storing personal/sensitive data to be processed by these devices has prompted a new breed of privacy concerns and problems to confront. In this thesis, we seek to show the influence and effects of five distinct types of interference rooted in the natural world on the functioning of magnetic sensor devices. Through the experiments conducted in this work, it was found that the interference forms of sound, temperature, and electromagnetism could induce a 32-36 percent average decrease in standard deviation in the data being processed by the sensor. Temperature shifting as an interference form also showed the potential for sizeable impacts on sensor functioning in terms of both increases and decreases. The largest decrease in standard deviation observed was 122 percent from the experiments with low temperature shifting. This work shows the incredible power and influence that the forces of nature can have on everyday devices and their need for data from their environment. The results observed from the temperature shift experiments also highlight the danger of leaving temperature based cyber-attacks under researched. The main use of this work is to fill the void in the current literature created by temperature based cyber-attacks and hopefully spur more research to be conducted into this method of cyber threat.

A requirements analysis approach for addressing the functional requirements of embedded systems has been proposed. Also proposed is a design approach based on the concurrent object-oriented programming paradigm. The design approach takes a specification created using the requirements analysis approach and transforms it into a detailed design. The detailed design is implemented using ACf++, a concurrent C++ that derives its concurrency semantics from the Actor model. The two approaches are illustrated by a simple but representative process control problem. The requirements analysis approach in conjunction with the design approach provides a high level of traceability and promotes the reusability of specifications and design. Improved reliability and reduced development and maintenance costs also are potential benefits. Extensions of the work include an integrated software development environment for embedded systems. / Master of Science

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper overviews the Research Environment for Vehicle-Embedded Analysis on Linux (REVEAL), which is an open standards framework for the creation and deployment of realtime embedded and network distributed data systems. REVEAL is an ongoing project at NASA Dryden to evaluate the feasibility and benefits of using Linux in a modern generic web-enabled data system for measurement and telemetry network research, by actually building such a system. Novel features are described, such as XML based self-configuring, self-verifying and self-documenting software, and automatic XML metadata generation. The REVEAL architecture is described, including the core server and scheduler, and the management of system and user job processing. Performance, timing, determinism, and security issues are discussed, as well as the advantages and limitations of Linux.