Physical Sciences and Mathematics Commons^™

Trust-But-Verify: Guaranteeing The Integrity Of User-Generated Content In Online Applications, Akshay Dua

Dissertations and Theses

Online applications that are open to participation lack reliable methods to establish the integrity of user-generated information. Users may unknowingly own compromised devices, or intentionally publish forged information. In these scenarios, applications need some way to determine the "correctness" of autonomously generated information. Towards that end, this thesis presents a "trust-but-verify" approach that enables open online applications to independently verify the information generated by each participant. In addition to enabling independent verification, our framework allows an application to verify less information from more trustworthy users and verify more information from less trustworthy ones. Thus, an application can trade-off performance for …

Equivalence Checking For High-Assurance Behavioral Synthesis, Kecheng Hao

Dissertations and Theses

The rapidly increasing complexities of hardware designs are forcing design methodologies and tools to move to the Electronic System Level (ESL), a higher abstraction level with better productivity than the state-of-the-art Register Transfer Level (RTL). Behavioral synthesis, which automatically synthesizes ESL behavioral specifications to RTL implementations, plays a central role in this transition. However, since behavioral synthesis is a complex and error-prone translation process, the lack of designers' confidence in its correctness becomes a major barrier to its wide adoption. Therefore, techniques for establishing equivalence between an ESL specification and its synthesized RTL implementation are critical to bring behavioral synthesis …

Type Classes And Instance Chains: A Relational Approach, John Garrett Morris

Dissertations and Theses

Type classes, first proposed during the design of the Haskell programming language, extend standard type systems to support overloaded functions. Since their introduction, type classes have been used to address a range of problems, from typing ordering and arithmetic operators to describing heterogeneous lists and limited subtyping. However, while type class programming is useful for a variety of practical problems, its wider use is limited by the inexpressiveness and hidden complexity of current mechanisms. We propose two improvements to existing class systems. First, we introduce several novel language features, instance chains and explicit failure, that increase the expressiveness of type …

Extending Technology Roadmap Through Fuzzy Cognitive Map-Based Scenarios: The Case Of The Wind Energy Sector Of Pakistan, Muhammad Amer

Dissertations and Theses

In this modern era, energy is a key element required for sustainable development and prosperity of a society. Pakistan is an energy deficient country facing problems due to the shortage of over 4000 MW of electricity. The national energy sector is heavily dependent on imported fossil-fuel resources. The energy crisis is negatively affecting all economic and business activities, and it is widely recognized as a severe obstacle to growth and poverty reduction in the country. Establishment of wind farms can help to overcome the energy crisis.

In this research, a national level wind energy roadmap is developed through scenario planning. …

Joint Angle Tracking With Inertial Sensors, Mahmoud Ahmed El-Gohary

Dissertations and Theses

The need to characterize normal and pathological human movement has consistently driven researchers to develop new tracking devices and to improve movement analysis systems. Movement has traditionally been captured by either optical, magnetic, mechanical, structured light, or acoustic systems. All of these systems have inherent limitations. Optical systems are costly, require fixed cameras in a controlled environment, and suffer from problems of occlusion. Similarly, acoustic and structured light systems suffer from the occlusion problem. Magnetic and radio frequency systems suffer from electromagnetic disturbances, noise and multipath problems. Mechanical systems have physical constraints that limit the natural body movement. Recently, the …

Just-In-Time Power Gating Of Gasp Circuits, Prachi Gulab Padwal

Dissertations and Theses

In modern integrated circuits, one way to reduce power consumption is to turn off power to parts of the circuit when those are idle. This method is called power gating. This thesis presents a state-preserving technique to achieve power savings in GasP family of asynchronous circuits by turning off the power when the circuit is idle. The power control logic turns on the power in anticipation of the receiving data. The power control logic turns off the power when the stage is idle either because it is empty or because the pipeline is clogged. The low logical effort of GasP …

Object Detection And Recognition In Natural Settings, George William Dittmar

Dissertations and Theses

Much research as of late has focused on biologically inspired vision models that are based on our understanding of how the visual cortex processes information. One prominent example of such a system is HMAX [17]. HMAX attempts to simulate the biological process for object recognition in cortex based on the model proposed by Hubel & Wiesel [10]. This thesis investigates the ability of an HMAX-like system (GLIMPSE [20]) to perform object-detection in cluttered natural scenes. I evaluate these results using the StreetScenes database from MIT [1, 8]. This thesis addresses three questions: (1) Can the GLIMPSE-based object detection system replicate …

Physical Unclonable Function Techniques Applied For Digital Hardware Protection, Anthony Barrera

Dissertations and Theses

"Privacy is an important property that is growing harder to keep as people develop new ways to steal information from users on their computers. Software alone cannot ensure privacy since an infected system is untrustworthy. This paper presents several challenges malware brings that can be solved by using an external processor. Techniques such as keystroke encryption and message authentication can be used to protect users from having their passwords and other private data stolen. To take advantage of the external hardware, a physical unclonable function can be used to generate private keys without the need for storing them in memory. …

Discrete Transforms With Good Time-Frequency And Spatial-Frequency Localization, David Chisholm

Dissertations and Theses

Discrete orthonormal time-frequency basis functions are described and used for both analysis and synthesis of complex-valued signals. We derive expressions for complex-valued expansion coefficients in time-frequency lattices in the discrete one dimensional case. This derivation is based on Professor I. Gertner's previous construction of a complete orthonormal set of basis functions well localized in the temporal-spatial-frequency domain in the continuous case. We describe how these can be generalized to any number of dimensions. Example applications are presented in one and two dimensions. Three dimensional basis functions are visualized and discussed. Finally, a full a Matlab implementation of this work is …

3d Hallway Modeling Using A Single Image, Gregory M. Olmschenk

Dissertations and Theses

"Real-time, low-resource corridor reconstruction using a single consumer grade RGB camera is a powerful tool for allowing a fast, inexpensive solution to indoor mobility of a visually impaired person or a robot. The perspective and known geometry of a corridor is used to extract the important features of the image and create a 3D model from a single image. Multiple 3D models can be combined to increase confidence and provide a global 3D model. This paper presents our results on 3D corridor modeling using single images. First a simple but effective 3D corridor modeling approach is introduced which makes very …