In this thesis, low-cost free chlorine sensors for monitoring drinking water have been developed. The starting material, pencil lead, was modified using a ammonium carbamate solution. The main emphasis for this technology is the low cost, scalable and environmental friendly process. The resultant materials were highly sensitive to free chlorine. The second discovery was an advanced understanding of the unsteady state mass transfer during the sensing process, using the customly expanded Cottrell equation. This method could qualitatively indicated the absence of free chlorine, for applications where the removal of free chlorine is the goal. This method allowed better interpretation of transient data and simplified setup. The third discovery was the use of pulsed amperometric detection to detect free chlorine at a much higher sensitivity, while reducing the complexity of the setup, further reducing the cost. This method was based on the previous findings plus understanding of the reaction kinetics. The resultant sensors detected free chlorine with a detection of 0.0414 ppm, while the regulations require the free chlorine to be above 0.2 ppm. The response time was less than three seconds. The range of detection was up to around 20 ppm. The cost of materials for one sensor was less than ten dollars. The maintenance was minimal due to the lack of consumables. The operation could be as a meter or as a device in a large instrument. The target use of the sensors include small and distant communities, bottling industries, fruit and vegetable washing industries. The free chlorine sensing techniques can be readily expanded to biology, environment, and big data applications, based on the knowledge gained through the study. / Thesis / Doctor of Philosophy (PhD) / Low-cost sensors were developed to monitor free chlorine in drinking water for end users, especially in small and distant communities. Free chlorine keeps lethal microorganism pathogens from re-growing after disinfection. Re-growth is more likely to happen in these communities due to poor infrastructure and less usage-driven flow. The contributions include: • A low-cost sensing material for free chlorine based on pencil lead • Determination of operating range of the sensor • Study of sensing mechanisms • Efficiency improvement and cost reduction • Research articles, conference presentations, patent applications, and industrial collaboration based on above research The resultant sensor is easy to use, robust in practical conditions and requires low maintenance, suitable for small and distant communities. Future work is the integration with sensing systems and the application of knowledge gained in this thesis for sensing applications in other fields.

Each year approximately 7,500 low-income Virginia families are enrolled in the Expanded Food and Nutrition Education Program (EFNEP), administered through the Virginia Cooperative Extension (VCE). Chronic disease and health conditions cost society an estimated $250 billion each year in medical charges and lost productivity. It has been assumed that the numerous diet and food-related changes made by EFNEP participants will lead to a reduction in the risk of chronic disease among homemakers, and perhaps, other family members. Thus, the improved diets and behaviors resulting from EFNEP participation may result in substantial future savings in healthcare costs among participants. This study explores the possibility of potential economic benefits for the Virginia EFNEP participants. In 1996, the Virginia Cooperative Extension was awarded a grant from the Cooperative State, Research, Education, and Extension Service, United States Department of Agriculture (CSREES, USDA) to conduct a cost-benefit study of EFNEP in Virginia. Though computation of the cost-benefit ratio for the Virginia adult EFNEP includes both direct and indirect benefits, this study addressed only the assessment of the direct tangible benefits based on the savings from economic costs of avoided diseases. Existing EFNEP data for the 1996 fiscal year was used to identify optimal nutritional behaviors that can delay or prevent the onset of certain chronic diseases and health conditions. The economic costs of diseases were identified from scientific literature and translated as potential benefits. The administration costs of EFNEP were also compiled. The total direct tangible benefit for the diseases and conditions identified was estimated to be $17,770,722. Along with the indirect tangible benefits ($321,462), the total tangible benefits for the Virginia EFNEP was calculated to be $18,092,184. The direct tangible costs associated with the Virginia EFNEP in 1996 was $1,922,204. The benefit-cost ratio for the Virginia EFNEP for the 1996 fiscal year for the subset of the population practicing the optimal nutritional behaviors is calculated at $9.41/$1.00 (a $9.41 return for every $1 invested in EFNEP in Virginia). Also, a benefit of $2.45 to $1.00 was calculated when only 25% of those participants practicing optimal nutritional behaviors were assumed retain these behaviors through life. For a program of the magnitude of EFNEP, these results are very gratifying. / Ph. D.

Researchers have consistently found that students and their parents have a distorted view of the costs of college attendance (Grodsky & Jones, 2004; Horn, Chen, & Chapman, 2003; Ikenberry & Hartle, 1998; Mumper, 1996). Those who are able to give an estimate of the tuition for various higher education alternatives often overestimate the actual price. When asked to estimate the tuition that in-state undergraduates would pay at four-year colleges in a given year, most students and their parents thought that the price was twice the actual amount (Horn et al., 2003b). Seventy-one percent of all individuals, and 83% of African-Americans believed that college was unaffordable for most families. The majority of individuals over-estimated the price by several thousands of dollars (Hartle, 1998). This study examined the literature on perceived price and used the theoretical construct based on the work of Nobel Prize winner Gary Becker to develop a methodology for studying whether students' perceived price of has a statistically significant impact on their plan to attend college and their actual matriculation. Applying Becker's theory, having faulty information on the price of attendance would result in people incorrectly weighting the cost-benefit equation and making what could be considered irrational decisions in the presence of complete information. Highlighting the problem of misperceived price is the contribution this study makes to the literature. Further study is warranted to determine the extent to which individuals use misperceived prices to make decisions on whether to plan to attend higher education. / Ph. D.

This dissertation consists of three essays in Applied Econometrics that seek a better understanding of different aspects of risk and risk management tools. The first essay is about mortality risk in Virginia coal regions. With a focus on the mortality of non-malignant respiratory diseases (NMRD), I estimate the impact of living in a coal county and find that coal-mining county residency significantly increases the probability of dying from NMRD. This statistical association is accentuated by surface coal mining, high smoking rates, lower health insurance coverage, and a shortage of doctors. The second essay evaluates the cost of a price risk management tool called futures hedging. A variety of measures illustrate considerable changes in hedging costs over time. Quantile regression results show that substantial price volatility and high margin requirements are the main factors driving high hedging costs from 2007 to 2013. The third paper investigates a health risk management tool, a public health insurance program in China called New Cooperative Medical Scheme (NCMS). I apply contract theory to characterize local governments' selective incentives in NCMS benefit designs. Empirical analysis of China Health and Nutrition Survey data indicate challenges of financial sustainability of this scheme in poor regions. The NCMS plan tends to under-cover the services that are moderately predictable and negatively correlated with plan profits, such as outpatient treatments. Preventive services are generally over-provided, perhaps due to the incentive to attract healthy participants. / Doctor of Philosophy / This dissertation uses quantitative analysis to investigate three economic problems related to different aspects of risk. The first question is, what affects the respiratory health of Virginia coal mining counties' residents? Using respiratory mortality as the variable of interest, this paper finds that surface coal mining, high smoking rates, and lack of health access jointly contribute to the elevated risk of dying from respiratory diseases in our study area. The second research problem is about a price risk management tool called "hedging": purchasing contracts in the futures market to offset price movements in the cash markets. Based on historical data of corn and soybeans, I simulate the cost of hedging and find this risk management tool is not cheap, especially in 2007 to 2013. The high cost is mainly due to substantial price fluctuations in the recent decade. As a health risk management tool, health insurance is the focus of my third study. In China rural areas, a public health scheme aimed to reduce a resident's risk of suffering medical impoverishment by spreading the risk over residents in a county. County governments were relatively free to design the implementation and benefit plans. This study reveals that most New Cooperative Medical Scheme (NCMS) benefit plans are not efficient to achieve the scheme's objective. Facing high risk of fund deficits, local insurance programs in poor regions are likely to under-cover health services, such as outpatient treatments. If this scheme were allowed to charge higher prices from high-risk enrollees instead of a flat-rate premium, its efficiency might be improved.

Continuous integration (CI) is a widely used practice in modern software engineering. Unfortunately, it is also an expensive practice — Google and Mozilla estimate their CI systems in millions of dollars. In this dissertation, I propose a collection of novel build selection approaches that are able to save the cost of CI. I also propose the first exhaustive comparison of techniques to improve CI including build and test granularity approaches. I firstly design a build selection approach (SMARTBUILDSKIP) for CI cost reduction in a balanceable way. The evaluation of SMARTBUILDSKIP shows that it can save a median of 30% of builds by only incurring a median delay of 1 build in a median of 15% of failing builds under its most conservative configuration. To minimize the delayed failure observation, I then propose the second build selection approach (PRECISEBUILDSKIP) that can save cost without delaying failure observation. We find that PRECISEBUILDSKIP can save a median of 5.5% of builds while capturing the majority of failing builds (100% in median) from the evaluation. After that, I evaluate the strengths and weaknesses of 10 techniques that can improve CI including SMARTBUILDSKIP. The findings of the comparison motivate my next work to design a hybrid technique (HYBRIDBUILDSKIP) that combines these techniques to produce more cost-saving while keeping a low proportion of failing builds that are delayed in observation. Finally, I design an experiment to understand how different weights of test duration among the whole build duration can influence the cost-saving of build and test selection techniques. / Doctor of Philosophy / Modern software developing teams commonly use the continuous integration as the practice of automating and testing the integration of code changes from multiple contributors into a single software project. The best practice of continuous integration requires this process happens as frequently as possible because the bugs can be found earlier and easier before the change sets grow too large. However, continuous integration process can be time-consuming and in most cases the code change is bug-free. This means that developers may have to wait for a long time only to get a result with no actionable feedback. Thus, in this dissertation, I present multiple selection approaches to selectively execute the continuous integration process based on the prediction of the outcome - if the outcome is predicted to be passing with no actionable feedback, the approach will decide to skip the current execution. The evaluation result shows that my approaches can save the cost of continuous integration while keeping the value of it (finding bugs earlier).

A simulation model analyzes cost effectiveness of remote facility monitoring for risk reduction in rural water supply systems by performing a break-even analysis that compares operating costs with manual and remote monitoring. Water system operating cost includes the value of water loss (i.e., realized risk) resulting from operating excursions which are inversely related to mechanical reliability. Reliability is controlled by facility monitoring that identifies excursions enabling operators to implement mitigating measures. Cost effectiveness refers to the cost relationship among operating alternatives that reveals changed economic conditions at different operating rates inherent in the inverse relationship between fixed and variable costs. Break-even analysis describes cost effectiveness by identifying the operating rate above which the more capital intensive alternative will result in lower operating cost. Evidence indicates that increased monitoring frequency associated with remote monitoring can reduce water system operating cost by improving reliability, but whether remote monitoring is cost effective depends upon system-specific factors. The lack of a documented tool for evaluating this type of cost effectiveness led to the project objective of developing a model that performs break-even analysis by simulating water system operating costs as functions of system size (delivery rate). When the spreadsheet-based static deterministic parametric simulation model is run for the Tazewell County, Virginia water system based upon 1998 data, break even is predicted at approximately fifty-five percent of annual capacity (116,338,000 gallons) with operating cost of $1,043,400. Maximum annual operating cost reduction from a $317,600 investment provides payback in nine years. / Master of Science

Reducing inefficiencies without compromising quality is a major challenge facing college and university leaders. Measuring efficiency and quality is often addressed through various statistical analyses (Archibald & Feldman, 2008; Flegg, Allen, & Thurlow, 2004). Researchers have also applied cost benefit analysis to measure efficiency. Collaboration is one mechanism used by university personnel to enhance efficiency and quality (Wiley, 2008). The literature on collaboration includes collaboration in research (Rigby & Elder, 2005), teaching (Kezar, 2005; Letterman & Dugan, 2004), and cross-divisional collaboration, learning communities (O’Connor & Associates, 2003). Residential colleges (where faculty live and work in residence halls) are another form of collaboration emerging across college campuses. A thorough review of the literature reveals no studies exploring the costs and benefits of residential colleges. The purpose of this study was to understand and describe the costs and benefits of residential colleges. The theoretical framework for this study was based on Nas’ (1996) cost benefit analysis framework. Data were collected through 60-90 minute telephone interviews with live-in faculty leaders of residential colleges and chief housing officers on campuses that offer residential colleges. Participants came from 11 different campus and included 12 chief housing officers and 11 faculty members. There are substantial institutional and individual costs associated with starting and maintaining a residential college. Institutional costs include departmental financial implications for facility renovations, staffing, and faculty incentives. Faculty principals and students bear individual costs. Impact on research, intensive time requirements for the position, and lack of recognition are costs affecting faculty. Residential college (RC) students incur additional fees and non-RC students are impacted by a diminished residential experience (as compared to their RC peers). Conversely, there are significant benefits resulting from residential colleges that may mitigate these costs. Institutions benefit from improved faculty pedagogy, expanded learning opportunities for students, and increased faculty connection to the institution. Individual benefits include positive faculty and student relationships (for faculty and students), increased understanding of students (for faculty), and faculty housing and other related incentives. / Ph. D.

Reducing inefficiencies without compromising quality is a major challenge facing college and university leaders. Measuring efficiency and quality is often addressed through various statistical analyses (Archibald and Feldman, 2008; Flegg, Allen, and Thurlow, 2004). Researchers have also applied cost benefit analysis to measure efficiency. Collaboration is one mechanism used by university personnel to enhance efficiency and quality (Wiley, 2008). The literature on collaboration includes collaboration in research (Rigby and Elder, 2005), teaching (Kezar, 2005; Letterman and Dugan, 2004), and cross-divisional collaboration, learning communities (O'Connor and Associates, 2003). Residential colleges (where faculty live and work in residence halls) are another form of collaboration emerging across college campuses. A thorough review of the literature reveals no studies exploring the costs and benefits of residential colleges. The purpose of this study was to understand and describe the costs and benefits of residential colleges. The theoretical framework for this study was based on Nas' (1996) cost benefit analysis framework. Data were collected through 60-90 minute telephone interviews with live-in faculty leaders of residential colleges and chief housing officers on campuses that offer residential colleges. Participants came from 11 different campus and included 12 chief housing officers and 11 faculty members. There are substantial institutional and individual costs associated with starting and maintaining a residential college. Institutional costs include departmental financial implications for facility renovations, staffing, and faculty incentives. Faculty principals and students bear individual costs. Impact on research, intensive time requirements for the position, and lack of recognition are costs affecting faculty. Residential college (RC) students incur additional fees and non-RC students are impacted by a diminished residential experience (as compared to their RC peers). Conversely, there are significant benefits resulting from residential colleges that may mitigate these costs. Institutions benefit from improved faculty pedagogy, expanded learning opportunities for students, and increased faculty connection to the institution. Individual benefits include positive faculty and student relationships (for faculty and students), increased understanding of students (for faculty), and faculty housing and other related incentives. / Ph. D.

Excessive use of fossil fuels to meet everyday energy demands has led to adverse environmental impacts like global warming and high dependence on foreign oil. Development of cellulosic feedstocks provides energy security and also reduces the burden on food crops like corn and sugarcane used for ethanol production. This thesis uses cost-benefit analysis to ascertain the profitability of producing cellulosic ethanol from Switchgrass and Sweet Sorghum Bagasse. First, breakeven price of producing Switchgrass and Sweet Sorghum is calculated to obtain a raw material (feedstock) cost for ethanol production. Next, net present value (NPV) and minimum ethanol selling price (MESP) for Switchgrass and Sweet sorghum are calculated. Lastly, risk analysis is performed and its impacts on NPV are calculated for two farmer categories. The results show that ethanol production from Switchgrass and Sweet Sorghum is commercially feasible and generates a Net Present Value (NPV) of $39.54 million for Switchgrass and $96.76 million for Sweet Sorghum at an ethanol selling price of $2.17 per gallon. At NPV zero the MESP for Switchgrass and Sweet Sorghum is estimated to be $2.10 and $1.96 per gallon respectively. The risk analysis results revealed that there is a 9.5 percent probability that the NPV for a risk-averse Switchgrass farmer will be less than zero. On the other hand, the probability of the NPV being less than zero is 67.4 percent. The overall analysis indicates that ethanol production from Switchgrass and Sweet Sorghum is a promising option. Reduction in feedstock prices, optimization of the conversion process and additional revenues from by-products can make cellulosic ethanol more competitive with current gasoline prices. / Master of Science

Maintenance costs in deregulated power systems play an important role. This mainly includes direct costs associated with material and labor costs; and indirect costs associated with spare parts inventory, shipment, test equipment cost, indirect labor, and opportunity costs. The cost function is used as the sole or main component of the objective function in maintenance scheduling and planning activities. The cost has been modeled in literature with several representations for centralized power systems. With deregulation of power industries in many countries the costs representation to be used within the maintenance model in the decentralized power systems has become an important research question. This paper presents modeling of different components of maintenance costs that can be used within the main objective function of the maintenance scheduling and planning problem for the deregulated environment.