A decision support framework for infrastructure maintenance investment decision-making

Infrastructure management agencies are facing multiple challenges, including aging infrastructure, reduction in capacity of existing infrastructure, and availability of limited funds. Therefore, decision makers are required to think innovatively and develop inventive ways of using available funds. Maintenance investment decisions are generally made based on physical condition only. It is important to understand that spending money on public infrastructure is synonymous with spending money on people themselves. This also requires consideration of decision parameters, in addition to physical condition, such as strategic importance, socioeconomic contribution and infrastructure utilization. Consideration of multiple decision parameters for infrastructure maintenance investments can be beneficial in case of limited funding. Given this motivation, this dissertation presents a prototype decision support framework to evaluate trade-off, among competing infrastructures, that are candidates for infrastructure maintenance, repair and rehabilitation investments. Decision parameters' performances measured through various factors are combined to determine the integrated state of an infrastructure using Multi-Attribute Utility Theory (MAUT). The integrated state, cost and benefit estimates of probable maintenance actions are utilized alongside expert opinion to develop transition probability and reward matrices for each probable maintenance action for a particular candidate infrastructure. These matrices are then used as an input to the Markov Decision Process (MDP) for the finite-stage dynamic programming model to perform project (candidate)-level analysis to determine optimized maintenance strategies based on reward maximization. The outcomes of project (candidate)-level analysis are then utilized to perform network-level analysis taking the portfolio management approach to determine a suitable portfolio under budgetary constraints. The major decision support outcomes of the prototype framework include performance trend curves, decision logic maps, and a network-level maintenance investment plan for the upcoming years. The framework has been implemented with a set of bridges considered as a network with the assistance of the Pima County DOT, AZ. It is expected that the concept of this prototype framework can help infrastructure management agencies better manage their available funds for maintenance.

Optimization of pavement maintenance and rehabilitation programming using shuffled complex evolution algorithm

The major barrier to practical optimization of pavement preservation programming has always been that for formulations where the identity of individual projects is preserved, the solution space grows exponentially with the problem size to an extent where it can become unmanageable by the traditional analytical optimization techniques within reasonable limit. This has been attributed to the problem of combinatorial explosion that is, exponential growth of the number of combinations. The relatively large number of constraints often presents in a real-life pavement preservation programming problems and the trade-off considerations required between preventive maintenance, rehabilitation and reconstruction, present yet another factor that contributes to the solution complexity. In this research study, a new integrated multi-year optimization procedure was developed to solve network level pavement preservation programming problems, through cost-effectiveness based evolutionary programming analysis, using the Shuffled Complex Evolution (SCE) algorithm.^ A case study problem was analyzed to illustrate the robustness and consistency of the SCE technique in solving network level pavement preservation problems. The output from this program is a list of maintenance and rehabilitation treatment (M&R) strategies for each identified segment of the network in each programming year, and the impact on the overall performance of the network, in terms of the performance levels of the recommended optimal M&R strategy. ^ The results show that the SCE is very efficient and consistent in the simultaneous consideration of the trade-off between various pavement preservation strategies, while preserving the identity of the individual network segments. The flexibility of the technique is also demonstrated, in the sense that, by suitably coding the problem parameters, it can be used to solve several forms of pavement management programming problems. It is recommended that for large networks, some sort of decomposition technique should be applied to aggregate sections, which exhibit similar performance characteristics into links, such that whatever M&R alternative is recommended for a link can be applied to all the sections connected to it. In this way the problem size, and hence the solution time, can be greatly reduced to a more manageable solution space. ^ The study concludes that the robust search characteristics of SCE are well suited for solving the combinatorial problems in long-term network level pavement M&R programming and provides a rich area for future research. ^

The maintenance of tracking: The role of organizational culture

Modern comprehensive high schools do not formally track students into different programs, but schools offer different curricular sequences with important and stratified consequences for students' post-secondary education. This study used qualitative methodology to examine how schools' organizational cultures influence the maintenance of tracking practices in four comprehensive high schools in Miami. The methodology included long-term participant observation in each of the four schools, unstructured and semi-structured interviews and the collection of written documents produced by the district. A framework based on the concepts of environment, mission, information, strategy, and leadership was used to analyze the data. ^ It was found that school cultures shared deeply held beliefs that regard ability as a fixed trait. This prevented schools from providing access to information about the consequences of course selection to the majority of the student body, with the exception of those students defined as “college bound.” State and County level policies that reward achievement in standardized tests combined with school overcrowding, resulted in organizational cultures that favored the adoption of strategies stressing efficiency, as opposed to a challenging education for all students. Only one of the four schools in the study had a policy requiring students to attempt courses that were more challenging. The practice was resented by both teachers and counselors, since it was perceived as interfering with other goals of the institution, i.e.: graduating students in four years. ^ The culture of the schools stressed college as the only legitimate post-secondary option; consequently, the majority of counselors did not encourage students—even those already defined as “not college material”—to consider other alternatives, such as vocational education. The elimination of formal tracks in these comprehensive high schools resulted in the school culture lacking a clear mission in regards to non-college bound students. Findings are discussed in relation to current theoretical explanations for educational policy and equality of opportunity. ^

The possible selves method in evaluating youth development interventions: The use of Integrated Qualitative /Quantitative Data Analytic Strategies (IQ -DAS)

This study investigated the feasibility of using qualitative methods to provide empirical documentation of the long-term qualitative change in the life course trajectories of “at risk” youth in a school based positive youth development program (the Changing Lives Program—CLP). This work draws from life course theory for a developmental framework and from recent advances in the use of qualitative methods in general and a grounded theory approach in particular. Grounded theory provided a methodological framework for conceptualizing the use of qualitative methods for assessing qualitative life change. The study investigated the feasibility of using the Possible Selves Questionnaire-Qualitative Extension (PSQ-QE) for evaluating the impact of the program on qualitative change in participants' life trajectory relative to a non-intervention control group. Integrated Qualitative/Quantitative Data Analytic Strategies (IQ-DAS) that we have been developing a part of our program of research provided the data analytic framework for the study. ^ Change was evaluated in 85 at risk high school students in CLP high school counseling groups over three assessment periods (pre, post, and follow-up), and a non-intervention control group of 23 students over two assessment periods (pre and post). Intervention gains and maintenance and the extent to which these patterns of change were moderated by gender and ethnicity were evaluated using a mixed design Repeated Measures Multivariate Analysis of Variance (RMANOVA) in which Time (pre, post) was the within (repeated) factor and Condition, Gender, and Ethnicity the between group factors. The trends for the direction of qualitative change were positive from pre to post and maintained at the year-end follow-up. More important, the 3-way interaction for Time x Gender x Ethnicity was significant, Roy's Θ =. 205, F(2, 37) = 3.80, p <.032, indicating that the overall pattern of positive change was significantly moderated by gender and ethnicity. Thus, the findings also provided preliminary evidence for a positive impact of the youth development program on long-term change in life course trajectory, and were suggestive with respect to the issue of amenability to treatment, i.e., the identification of subgroups of individuals in a target population who are likely to be the most amenable or responsive to a treatment. ^

The maintenance of tracking : the role of organizational culture

Modern comprehensive high schools do not formally track students into different programs, but schools offer different curricular sequences with important and stratified consequences for students' post-secondary education. This study used qualitative methodology to examine how schools' organizational cultures influence the maintenance of tracking practices in four comprehensive high schools in Miami. The methodology included long-term participant observation in each of the four schools, unstructured and semi-structured interviews and the collection of written documents produced by the district. A framework based on the concepts of environment, mission,, information, strategy, and leadership was used to analyze the data. It was found that school cultures shared deeply held beliefs that regard ability as a fixed trait. This prevented schools from providing access to information about the consequences of course selection to the majority of the student body, with the exception of those students defined as "college bound." State and County level policies that reward achievement in standardized tests combined with school overcrowding, resulted in organizational cultures that favored the adoption of strategies stressing efficiency, as opposed to a challenging education for all students. Only one of the four schools in the study had a policy requiring students to attempt courses that were more challenging. The practice was resented by both teachers and counselors, since it was perceived as interfering with other goals of the institution, i.e.: graduating students in four years. The culture of the schools stressed college as the only legitimate post-secondary option; consequently, the majority of counselors did not encourage students-even those already defined as "not college material"-to consider other alternatives, such as vocational education. The elimination of formal tracks in these comprehensive high schools resulted in the school culture lacking a clear mission in regards to non-college bound students. Findings are discussed in relation to current theoretical explanations for educational policy and equality of opportunity.