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Description
Calcium hydroxide carbonation processes were studied to investigate the potential for abiotic soil improvement. Different mixtures of common soil constituents such as sand, clay, and granite were mixed with a calcium hydroxide slurry and carbonated at approximately 860 psi. While the carbonation was successful and calcite formation was strong on sample exteriors, a 4 mm passivating boundary layer effect was observed, impeding the carbonation process at the center. XRD analysis was used to characterize the extent of carbonation, indicating extremely poor carbonation and therefore CO2 penetration inside the visible boundary. The depth of the passivating layer was found to be independent of both time and choice of aggregate. Less than adequate strength was developed in carbonated trials due to formation of small, weakly-connected crystals, shown with SEM analysis. Additional research, especially in situ analysis with thermogravimetric analysis would be useful to determine the causation of poor carbonation performance. This technology has great potential to substitute for certain Portland cement applications if these issues can be addressed.
ContributorsHermens, Stephen Edward (Author) / Bearat, Hamdallah (Thesis director) / Dai, Lenore (Committee member) / Mobasher, Barzin (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor)
Created2015-05
Description
Cyber threats are growing in number and sophistication making it important to continually study and improve all dimensions of digital forensics. Teamwork in forensic analysis has been overlooked in systems even though forensics relies on collaboration. Forensic analysis lacks a system that is flexible and available on different electronic devices which are being used and incorporated into everyday life. For instance, cellphones or tablets that are easy to bring on-the-go to sites where the first steps of forensic analysis is done. Due to the present day conversion to online accessibility, most electronic devices connect to the internet. Squeegee is a proof of concept that forensic analysis can be done on the web. The forensic analysis expansion to the web opens many doors to collaboration and accessibility.
ContributorsJuntiff, Samantha Maria (Author) / Ahn, Gail-Joon (Thesis director) / Kashiwagi, Jacob (Committee member) / Barrett, The Honors College (Contributor) / Computer Science and Engineering Program (Contributor)
Created2015-05
Description
Food safety is vital to the well-being of society; therefore, it is important to inspect food products to ensure minimal health risks are present. A crucial phase of food inspection is the identification of foreign particles found in the sample, such as insect body parts. The presence of certain species of insects, especially storage beetles, is a reliable indicator of possible contamination during storage and food processing. However, the current approach to identifying species is visual examination by human analysts; this method is rather subjective and time-consuming. Furthermore, confident identification requires extensive experience and training. To aid this inspection process, we have developed in collaboration with FDA analysts some image analysis-based machine intelligence to achieve species identification with up to 90% accuracy. The current project is a continuation of this development effort. Here we present an image analysis environment that allows practical deployment of the machine intelligence on computers with limited processing power and memory. Using this environment, users can prepare input sets by selecting images for analysis, and inspect these images through the integrated pan, zoom, and color analysis capabilities. After species analysis, the results panel allows the user to compare the analyzed images with referenced images of the proposed species. Further additions to this environment should include a log of previously analyzed images, and eventually extend to interaction with a central cloud repository of images through a web-based interface. Additional issues to address include standardization of image layout, extension of the feature-extraction algorithm, and utilizing image classification to build a central search engine for widespread usage.
ContributorsMartin, Daniel Luis (Author) / Ahn, Gail-Joon (Thesis director) / Doupé, Adam (Committee member) / Xu, Joshua (Committee member) / Computer Science and Engineering Program (Contributor) / Department of Finance (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Radio Frequency Identification (RFID) technology allows objects to be identified electronically by way of a small electronic tag. RFID is quickly becoming quite popular, and there are many security hurdles for this technology to overcome. The iCLASS line of RFID, produced by HID Global, is one such technology that is widely used for secure access control and applications where a contactless authentication element is desirable. Unfortunately, iCLASS has been shown to have security issues. Nevertheless customers continue to use it because of the great cost that would be required to completely replace it. This Honors Thesis will address attacks against iCLASS and means for countering them that do not require such an overhaul.
ContributorsMellott, Matthew John (Author) / Ahn, Gail-Joon (Thesis director) / Thorstenson, Tina (Committee member) / Barrett, The Honors College (Contributor) / Computer Science and Engineering Program (Contributor)
Created2014-05
Description
Over the past several years, the three major mobile platforms have seen
tremendous growth and success; as a result, the platforms have been the target
of many malicious attacks. These attacks often request certain permissions in
order to carry out the malicious activities, and uninformed users usually grant
them. One prevalent example of this type of malware is one that requests
permission to the device’s SMS service, and once obtained, uses the SMS
service to accrue charges to the user. This type of attack is one of the most
prevalent on the Android application marketplace, and requires a long-term
solution. Replication of an attack is necessary to fully understand efficient
prevention methods, and due to the open-source nature of Android development,
to determine the likely mechanics of the attack as feasible.
This study uses the Hacker News application, an open source application
that is available for download through GitHub as a basis for creating a malware
application to study the SMS attack and explore prevention methods. From the
results and knowledge gained from both research and experimentation, a
proposition for a more secure operating system architecture was defined to
prevent and mitigate various attacks on mobile systems with a focus on SMS
attacks.
tremendous growth and success; as a result, the platforms have been the target
of many malicious attacks. These attacks often request certain permissions in
order to carry out the malicious activities, and uninformed users usually grant
them. One prevalent example of this type of malware is one that requests
permission to the device’s SMS service, and once obtained, uses the SMS
service to accrue charges to the user. This type of attack is one of the most
prevalent on the Android application marketplace, and requires a long-term
solution. Replication of an attack is necessary to fully understand efficient
prevention methods, and due to the open-source nature of Android development,
to determine the likely mechanics of the attack as feasible.
This study uses the Hacker News application, an open source application
that is available for download through GitHub as a basis for creating a malware
application to study the SMS attack and explore prevention methods. From the
results and knowledge gained from both research and experimentation, a
proposition for a more secure operating system architecture was defined to
prevent and mitigate various attacks on mobile systems with a focus on SMS
attacks.
ContributorsRomo, James Tyler (Co-author) / Rezende, Bryan (Co-author) / Whitaker, Jeremy (Co-author) / Ahn, Gail-Joon (Thesis director) / Wilkerson, Kelly (Committee member) / Conquest, Kevin (Committee member) / Barrett, The Honors College (Contributor) / Computer Science and Engineering Program (Contributor)
Created2013-05
Description
Modern computer processors contain an embedded firmware known as microcode that controls decode and execution of x86 instructions. Although proprietary and relatively obscure, this microcode can be modified using updates released by hardware manufacturers to correct processor logic flaws (errata). At the same time, a malicious microcode update could compromise a processor by implementing new malicious instructions or altering the functionality of existing instructions, including processor-accelerated virtualization or cryptographic primitives. Not only is this attack vector capable of subverting all software-enforced security policies and access controls, but it also leaves behind no postmortem forensic evidence since the write-only patch memory is cleared upon system reset. Although supervisor privileges (ring zero) are required to update processor microcode, this attack cannot be easily mitigated due to the implementation of microcode update functionality within processor silicon. In this paper, we reveal the microarchitecture and mechanism of microcode updates, present a security analysis of this attack vector, and provide some mitigation suggestions.
ContributorsChen, Daming Dominic (Author) / Ahn, Gail-Joon (Thesis director) / Lee, Joohyung (Committee member) / Barrett, The Honors College (Contributor) / Computer Science and Engineering Program (Contributor) / School of International Letters and Cultures (Contributor) / School of Mathematical and Statistical Sciences (Contributor)
Created2014-05
Description
Our goals in our project are to enable management of distributed systems from one central location, record system logs and audit system based on these logs, and to demonstrate feasibility of platform-independent management of distributed systems based on CIM schema. In order to achieve these goals, we will have to overcome research challenges such as identifying meaningful CIM classes and attributes that could help to achieve this goal, how to gather managed objects of these CIM classes to collect such attributes on a given platform, and to research whether a platform's implementation of CIM is complete or incomplete so as to decide which platform would be the best to implement our solution. Even if a platform's implementation of CIM is incomplete, would we be able to create our own solution to a missing attribute and perhaps provide our own extension of the implementation? One major practical accomplishment will include developing a tool to allow distributed systems management regardless of a target system's platform. However, our research accomplishments will include having found the CIM classes that would be advantageous for system management and determining which platform would be best to work with managed objects of these classes.
ContributorsTrang, Patrick D (Author) / Ahn, Gail-Joon (Thesis director) / Chen, Yinong (Committee member) / Wilson, Adrian (Committee member) / Barrett, The Honors College (Contributor) / Computer Science and Engineering Program (Contributor)
Created2013-05
Description
As green buildings become more popular, the challenge of structural engineer is to move beyond simply green to develop sustainable, and high-performing buildings that are more than just environmentally friendly. For decades, Portland cement-based products have been known as the most commonly used construction materials in the world, and as a result, cement production is a significant source of global carbon dioxide (CO2) emissions, and environmental impacts at all stages of the process. In recent years, the increasing cost of energy and resource supplies, and concerns related to greenhouse gas emissions and environmental impacts have ignited more interests in utilizing waste and by-product materials as the primary ingredient to replace ordinary Portland cement in concrete systems. The environmental benefits of cement replacement are enormous, including the diversion of non-recycled waste from landfills for useful applications, the reduction in non-renewable energy consumption for cement production, and the corresponding emission of greenhouse gases. In the vast available body of literature, concretes consisting activated fly ash or slag as the binder have been shown to have high compressive strengths, and resistance to fire and chemical attack. This research focuses to utilize fly ash, by-product of coal fired power plant along with different alkaline solutions to form a final product with comparable properties to or superior than those of ordinary Portland cement concrete. Fly ash mortars using different concentration of sodium hydroxide and waterglass were dry and moist cured at different temperatures prior subjecting to uniaxial compressive loading condition. Since moist curing continuously supplies water for the hydration process of activated fly ash mortars while preventing thermal shrinkage and cracking, the samples were more durable and demonstrated a noticeably higher compressive strength. The influence of the concentration of the activating agent (4, or 8 M sodium hydroxide solution), and activator-to-binder ratio of 0.40 on the compressive strengths of concretes containing Class F fly ash as the sole binder is analyzed. Furthermore, liquid sodium silicate (waterglass) with silica modulus of 1.0 and 2.0 along with activator-to-binder ratio of 0.04 and 0.07 was also studied to understand its performance in contributing to the strength development of the activated fly ash concrete. Statistical analysis of the compressive strength results show that the available alkali concentration has a larger influence on the compressive strengths of activated concretes made using fly ash than the influence of curing parameters (elevated temperatures, condition, and duration).
ContributorsBanh, Kingsten Chi (Author) / Neithalath, Narayanan (Thesis director) / Rajan, Subramaniam (Committee member) / Mobasher, Barzin (Committee member) / Civil, Environmental and Sustainable Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2013-05
Description
We discuss processes involved in user-centric security design, including the synthesis of goals based on security and usability tasks. We suggest the usage of implicit security and the facilitation of secureuser actions. We propose a process for evaluating usability flaws by treating them as security threats and adapting traditional HCI methods. We discuss how to correct these flaws once they are discovered. Finally, we discuss the Usable Security Development Model for developing usable secure systems.
ContributorsJorgensen, Jan Drake (Author) / Ahn, Gail-Joon (Thesis director) / VanLehn, Kurt (Committee member) / Wilkerson, Kelly (Committee member) / Barrett, The Honors College (Contributor) / Computer Science and Engineering Program (Contributor)
Created2013-05
Finite element analysis of silicon thin films on soft substrates as anodes for lithium ion batteries
Description
The wide-scale use of green technologies such as electric vehicles has been slowed due to insufficient means of storing enough portable energy. Therefore it is critical that efficient storage mediums be developed in order to transform abundant renewable energy into an on-demand source of power. Lithium (Li) ion batteries are seeing a stream of improvements as they are introduced into many consumer electronics, electric vehicles and aircraft, and medical devices. Li-ion batteries are well suited for portable applications because of their high energy-to-weight ratios, high energy densities, and reasonable life cycles. Current research into Li-ion batteries is focused on enhancing its energy density, and by changing the electrode materials, greater energy capacities can be realized. Silicon (Si) is a very attractive option because it has the highest known theoretical charge capacity. Current Si anodes, however, suffer from early capacity fading caused by pulverization from the stresses induced by large volumetric changes that occur during charging and discharging. An innovative system aimed at resolving this issue is being developed. This system incorporates a thin Si film bonded to an elastomeric substrate which is intended to provide the desired stress relief. Non-linear finite element simulations have shown that a significant amount of deformation can be accommodated until a critical threshold of Li concentration is reached; beyond which buckling is induced and a wavy structure appears. When compared to a similar system using rigid substrates where no buckling occurs, the stress is reduced by an order of magnitude, significantly prolonging the life of the Si anode. Thus the stress can be released at high Li-ion diffusion induced strains by buckling the Si thin film. Several aspects of this anode system have been analyzed including studying the effects of charge rate and thin film plasticity, and the results are compared with preliminary empirical measurements to show great promise. This study serves as the basis for a radical resolution to one of the few remaining barriers left in the development of high performing Si based electrodes for Li-ion batteries.
ContributorsShaffer, Joseph (Author) / Jiang, Hanqing (Thesis advisor) / Rajan, Subramaniam D. (Committee member) / Peralta, Pedro (Committee member) / Arizona State University (Publisher)
Created2011