Secure State Estimation in the Presence of False Information Injection Attacks

In this dissertation, we first investigate the problem of source location estimation in wireless sensor networks (WSNs) based on quantized data in the presence of false information attacks. Using a Gaussian mixture to model the possible attacks, we develop a maximum likelihood estimator (MLE) to estimate the source location. The Cramer-Rao lower bound (CRLB) for this estimation problem is also derived. Then, the assumption that the fusion center does not have the knowledge of the attack probability and the attack noise power investigated. We assume that the attack probability and power are random variables which follow certain uniform distributions. We derive the MLE for the localization problem. The CRLB for this estimation problem is also derived. It is shown that the proposed estimator is robust in various cases with different attack probabilities and parameter mismatch. The linear state estimation problem subjected to False Information Injection is also considered. The relationship between the attacker and the defender is modeled from a minimax perspective, in which the attacker tries to maximize the cost function. On the other hand, the defender tries to optimize the detection threshold selection to minimize the cost function. We consider that the attacker will attack with deterministic bias, then we also considered the random bias. In both cases, we derive the probabilities of detection and miss, and the probability of false alarm is derived based on the Chi squared distribution. We solve the minimax optimization problem numerically for both the cases

Developing Ultra-High Performance Concrete (UHPC) with Locally Available Materials

Ultra-High Performance Concrete (UHPC) can enhance the durability and resilience of concrete structures. The use of local materials is a fundamental step to save energy and reduce the cost of concrete. The main focus of this research was to develop a UHPC with compressive strength of 150 MPa using locally sources materials. In this study, the effect of fine materials, binder type and content, type of mixer, steel fibers and curing regimes on concrete’s compressive strength were investigated. The relationship between compressive strength and elastic modulus was also studied. This study synthesizes all relevant experimental data in the literature to propose a new equation for predicting the modulus of elasticity (MOE) at different ages. A number of UHPC mixtures were developed to verify the accuracy of the proposed equation. With an error of ±10%, the proposed equation provides a reasonable prediction for the UHPC mixtures containing local materials. The final part of the dissertation focuses on developing economical UHPC mixtures by reducing the amount of binder content by using of ash. Costs were compared with the UHPC mixtures that are available in the market, indicating $283/m3 compared to approximately$200/m3 with current products

Is Information Systems Misuse Always Bad? A New Perspective on IS Misuse in Hospitals Under the Context of Disasters

Although the extant literature has investigated how individuals engage in inappropriate behaviors based on the rational choice theory (RCT) (e.g., computer misconduct), the neutralization theory (e.g., IS security policies violation), and workarounds under normal situations, it has given little consideration to how individuals are involved in misuse of information systems with a good intention under the context of disasters. To fill this research gap, we propose a selfless misuse model, which offers a theoretical explanation for the concept of individuals’ selfless misuse intention under uncertainty caused by disasters. In this study, we show why employees make decisions to misuse the information system to ensure delivery of health services and business continuity. In addition, we explore the way of reducing this misuse behavior by introducing the role of system resilience in assisting employees to make better decisions and act positively

Building Successful Collaborative Practices Among Early Childhood Educators: Understanding the Role of Educator Preparation Programs

This qualitative case study was designed to explore the role of early childhood education and early childhood special education personnel preparation programs in providing training in effective professional collaboration knowledge and skills to preservice early childhood professionals. Effective collaboration practices are important processes that contribute to the creation of successful inclusion programs. Preparing preservice educators to demonstrate effective collaboration skills is critical to promoting positive attitudes and initiating successful collaboration practices that support inclusion in preschools. The evidence was collected through different sources such as interviews with program faculty and undergraduate students, reviews of course documents, and observations of classes. The data provided in-depth information regarding the extent that the two programs prepare their pre-service teachers to develop effective collaboration skills. The experiences of the program faculty and students toward collaboration and teaming were positive and supportive in general. The program faculty and students identified several challenges in teaching and learning about professional collaboration and provided multiple recommendations to improve training of preservice teachers in professional collaboration practices. Furthermore, the findings of the study regarding the methods of training in collaboration and teaming indicated a need to increase applied collaboration skills through coursework, field experiences, and practica. Providing professional collaboration knowledge with limited opportunities to practice collaboration skills was insufficient to prepare preservice early childhood teachers to be effective collaborators with other professionals in inclusive preschools. In addition, the findings highlighted similarities and differences between the early childhood education program and the early childhood special education program regarding training in collaboration. The findings of this study led to recommendations for policy, personnel preparation practices, and future research in order to prepare early childhood professionals to collaborate with other education professionals to enhance the quality of inclusive programs in early childhood settings

Essays On The Effects Of Oil Price Shocks On The U.s. Stock Returns

This research investigates the effect of changes in oil prices and oil price volatility on the U.S. stock returns. The first essay tests whether the sign and the size of oil price shocks matter for the U.S. stock returns. The results suggest a linear model provides a good approximation to the response of real stock returns to real oil price innovations. However, this is not the case when the model is specified in terms of the nominal price of crude oil.Using a modified structural VAR to accommodate GARCH-in-Mean errors, the second essay studies the direct effects of oil price uncertainty on the U.S. stock returns at the aggregate and sectoral levels. We also simulate the response of U.S. stock returns to positive and negative oil price shocks, to examine whether the responses to positive and negative shocks are symmetric.Estimation results suggest that there is no statistically significant effect of oil price volatility on the U.S. stock returns. Moreover, the impulse responses indicate that oil price increases and decreases have symmetric effects on the U.S. stock returns. Using high frequency data, thethird essay addresses the issue of uncertainty in oil prices and its effect on U.S. stock returns, taking into account the day of the week effect. The results suggest that the-day-of-the-week effect is present in both the mean and volatility equations. The results also show that the U.S. stock market is sensitive to oil price variations not only at the aggregate level but also across some industries, such as chemicals, entertainment, and retail, where uncertainty in oil prices proves to have positive and statistically significant effect

Binding studies of E-Cadherin peptides to the EC1 domain of E-Cadherin

The blood brain barrier (BBB) is a key role in delivering medication to the brain; if the drug molecules can overcome this obstacle, many brain diseases (i.e., Alzheimer's, Parkinson's, and brain tumor) can be effectively treated. E-cadherin is important in forming cell-cell adhesion in intercellular junctions of the biological barriers (i.e., intestinal mucosa and BBB). Cadherin peptides (HAV6 and ADTC5) have been shown to modulate the BBB in the cell culture and in in-situ rat brain perfusion models. The hypothesis is that cadherin peptides modulate the tight junctions of the BBB by binding to the EC1 domain of E-cadherin. Thus, the objective of this project is to determine the dissociation constants (Kds) of linear and cyclic cadherin peptides (i.e., HAV- and ADT-peptides) to the expressed EC1 domain of E-cadherin using circular dichroism (CD) spectroscopy. The data show that the cyclic HAVc3 peptide (Kd = 66.7±18.0 nM) has better binding property to the EC1 domain than the linear HAV6 peptide (Kd = 120.1±11.9 nM). Cyclic ADTC5 (Kd = 50.2± 11 nM) has lower dissociation constant than ADTC1 (Kd = 119.7± 16 nM). Mutation of the valine residue in ADTC5 to glutamic acid (ADTC7; Kd = 0.43± 0.050 nM) and threonine (ADTC8; Kd = 0.45±0.012) makes the peptides to have 100-fold tighter binding compared to the EC1 domain. Mutation of the valine residue in ADTC5 to a tyrosine residue (ADTC9; Kd = 0.038± 0.009) increases binding to the EC1 domain by 1000-fold. Finally, mutation of the valine residue to arginine demolishes the activity of ADTC10. In the future, the activity of ADTC9 to modulate the BBB will be compared to ADTC5 in in vitro and in vivo models of the BBB

Development and Evaluation of the Assessment of Opioid Taking Behaviors and Adherence Scale (AOTBA) in Patients with Sickle Cell Disease

The rapid growth in opioid therapy for non-cancer pain has occurred without an adequate appreciation of the consequences of this growth. Few studies provide patient-centered evidence that can be used to inform the current proposed standards for efficacious (safe and effective) opioid prescribing in non-cancer pain. Furthermore, different terms may be used interchangeably in the literature to refer to opioid-taking behaviors, resulting in imprecise or vague interpretation of existing evidence. We therefore sought to explore patterns of opioid-taking behavior and their biopsychosocial-spiritual determinants in African-American adults with sickle cell disease (SCD). Many questions surround opioid use for non-cancer pain, but little has been published about behavioral patterns of taking opioids in these conditions. The main objective of this study was to develop a disease-specific scale for describing prescribed opioid taking in patients with sickle cell disease (SCD). As part of a multiphase, mixed-methods study, we used an adaptation of several published methods to construct 9 sequential, chronological steps for developing a new scale. We report here wide-ranging quantitative and semi-structured, qualitative interviews of 13 male and 11 female African-American adults with SCD, average age 36 years, from various socioeconomic and educational levels. We used grounded theory, priori and posteriori procedures to analyze the qualitative data, and to conduct an appraisal of translational validity. Scale development results have led to inclusion in the draft scale of new concepts namely momentary medication-taking behavior. The scale also captures concrete patterns of adherence for as-needed and scheduled medication and allows for several discovered conceptual domains that explain observed opioid-taking behaviors. These concepts challenge the current theories and models of medication-taking behavior and adherence. In summary, we found that contextual factors may drastically affect opioid-taking behaviors. Together, These uncovered phenomena raise new hypotheses that may challenge current theories and models of medication-taking behaviors and methods of assessing adherence. These hypotheses call for a new round of research on opioid-taking behavior, and need to be rigorously tested in future researc