Thesis advisor: Martin Scanlan / District improvement research highlights the importance of central office leaders and building principals in reform efforts. A growing body of literature emphasizes the importance of the relationship between central office leaders and principals in the context of turnaround school reform. Drawing on research from Honig (2012), the assistance relationship consistently surfaced as a key element of success when selecting and implementing learning time as a turnaround measure. This study aims to explore the assistance relationship between central office leaders and principals in the selection and implementation of learning time. This qualitative study draws upon observations and document review to answer the research questions, and is one strand of a larger research project studying how central office leaders support principals through an assistance relationship in a district in receivership. This individual strand concludes that the selection and implementation of learning time opportunities, without consideration to the principals and without the assistance of central office leaders, can’t happen. This strand advances our understanding of how an effective assistance relationship can work in a district in receivership. I concluded that central office leaders and principals interviewed selected and implemented like learning time opportunities. Future researchers may continue to enrich this growing body of literature by examining these findings and testing all or some of the five key practices in a like district. The results, implications for districts in receivership, and future research are discussed. This strand’s findings can serve as a companion for central office leaders who are working with principals to select and implement learning time opportunities in order to improving achievement levels in underperforming schools and districts across our country. / Thesis (EdD) — Boston College, 2018. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Leadership and Higher Education.

We have built an application that integrates a technical editor feature and a custom real-time strategy game. The end users are able to use the technical editor feature for tweaking and customizing the unit attributes and progressions in the game using simple mathematical formulas, and they can play or test their tweaked formulas within the game. Various game modes in the software, which are Single Player, Multiplayer, and Simulation, can help display to the end users the results of their tweaked formulas, or users can just have fun by playing the game. The software was evaluated to see whether the software with the editor feature enabled is more attractive and appealing to the end users than the software with the editor feature disabled. The evaluation is based on the players’ feedback on the game with or without the editor. A total of 50 testers were randomly assigned into 2 groups evenly, the Tool group and the Game group. Testers assigned to the Tool group were able to customize the game unit attributes via the editor and play, while the testers in the Game group only play the game. The results from the post-test survey show both versions of the software are highly appealing to the testers, and there is no significant difference in game appeals between the Tool version and the Game version.

Timber harvesting is an important activity in the state of Kentucky; however, there is still a lack of information about the procedure used by the local loggers. The stump to landing transport of logs with skidders is often the most expensive and time-consuming task in timber harvesting operations. This thesis evaluated the feasibility of using a multi-camera system for time and motion studies of timber harvesting operations. It was installed in 5 skidders in 3 different harvesting sites in Kentucky. The time stamped video provided accurate time consumption data for each work phase of the skidders, which was used to fit linear regressions and find the influence of skidding distance, skid-trail gradient, and load size on skidding time. The multi-camera systems were found to be a reliable tool for time and motion studies in timber harvesting sites. Six different time equations and two speed equations were fitted for skidding cycles and sections of skid-trails, for skidders that are both loaded and unloaded. Skid-trail gradient and load size did not have an influence on skidding time. There is a need for future studies of different variables that could affect skidding time and, consequently, cost.

In a controlled lab experiment, we investigate hypothetical biases in the value of time by comparing stated preference (SP) and revealed preference (RP) values attached to unexpected waiting times. The SP and RP choice sets are identical in terms of design with the only difference being that the RP choices have real consequences in terms of unexpected waiting times and monetary incentives. We find a substantial hypothetical bias with the average SP value of time being only 71% of the corresponding RP value. The bias is mainly driven by participants who have scheduling constraints during the time of the unexpected wait. Scheduling constraints are taken into account to a much lesser extent in the SP setting than in the RP setting, presumably because only in the latter, the consequences of ignoring them are costly. We find evidence that this effect is stronger for persons with relatively low cognitive ability.

Abstract not available

Traditionally, the compilation of long-term timetables for high-density rail service with multiple classes of trains on the same track is a job for expert people, not computers. We propose an algorithm that uses the range-constriction search technique to schedule the timing and pass-through relations of trains smoothly and efficiently. The program determines how the timing of certain trains constrains the timing of others, finds possible time regions and pass-through relations and then evaluates the efficiency of train movement for each pass-through relation.

Ph.D. / Electrical and Computer Engineering / Numerous applications require either the estimation or prediction of a noisy time-series. Examples include speech enhancement, economic forecasting, and geophysical modeling. A noisy time-series can be described in terms of a probabilistic model, which accounts for both the deterministic and stochastic components of the dynamics. Such a model can be used with a Kalman filter (or extended Kalman filter) to estimate and predict the time-series from noisy measurements. When the model is unknown, it must be estimated as well; dual estimation refers to the problem of estimating both the time-series, and its underlying probabilistic model, from noisy data. The majority of dual estimation techniques in the literature are for signals described by linear models, and many are restricted to off-line application domains. Using a probabilistic approach to dual estimation, this work unifies many of the approaches in the literature within a common theoretical and algorithmic framework, and extends their capabilities to include sequential dual estimation of both linear and nonlinear signals. The dual Kalman filtering method is developed as a method for minimizing a variety of dual estimation cost functions, and is shown to be an effective general method for estimating the signal, model parameters, and noise variances in both on-line and off-line environments.

The objective of this research is to demonstrate experimentally the feasibility of using the Internet for a Distributed Control System (DCS). An algorithm has been designed and implemented to ensure stability of the system in the presence of upper bounded time-varying delays. A single actuator magnetic ball levitation system has been used as a test bed to validate the proposed algorithm. Experiments were performed to obtain the round-trip time delay between the host PC and the client PC under varying network loads and at different times. A digital real-time lead-lag controller was implemented for the magnetic levitation system. Upper bounds for the artificial and experimental round-trip time delay that can be accommodated in the control loop for the maglev system were estimated. The artificial time delay was based on various probabilistic distributions and was generated through MATLAB. To accommodate sporadic surges in time delays that are more than these upper bounds, a timeout algorithm with sensor data prediction was developed. Experiments were performed to validate the satisfactory performance of this algorithm in the presence of the bonded sporadic excessive time delays.

Methods for performing response time analysis of real-timesystems are important, not only for their use in traditionalschedulability testing, but also for deriving bounds on outputtiming variations in control applications. Automatic controlsystems are inherently sensitive to variations in periodicityand end-to-end delays. Therefore, real-time performance needsto be considered during control design. For this purpose, anyreal-time analysis of a potential control implementation shouldproduce results that can easily be used to examine how theimplementation affects control performance. To find the maximumresponse time variation for a task, bounds on both minimum andmaximum response times are needed. A tight bound on thismaximum variation is useful in the analysis of controlperformance and can also be used to improve the results of someiterative response time analysis methods. In this thesis, threemethods for response time analysis are developed. While earlier research has focused on bounding maximumresponse times, one of the analysis methods in this thesisallows a computation of the minimum response times ofindependent fixed priority scheduled tasks. The analysis findsthe largest lower bound of response times for such tasks, whichleads to a tighter bound on the response time variations. Asecond analysis method allows exact computation of maximumresponse times for tasks whose arrival times are related byoffsets. The method is a complement to schedule simulationbased analysis, which it outperforms for systems with tasksthat may experience release jitter. A common design principle for distributed real-time systemsis to let the completion of one task trigger the start of oneor more successors. A third method supporting the analysis oftasks in such systems is described. The method extends andimproves earlier methods as it allows a generalized systemmodel and also results in tighter bounds than the originalmethods. This method has been implemented as part of a toolsetthat enables an integrated approach to the design and analysisof control systems and their implementation as distributedreal-time systems. As part of the thesis, models for describingdistributed control systems have been developed. The toolset,which is based on these models, uses the derived response timebounds in a control system performance analysis based onsimulation. The use of the toolset is exemplified in a smallcase study. <b>Keywords:</b>real-time systems, scheduling, response time,fixed priority, control, jitter, offset, schedulabilityanalysis

Winterfat (Krascheninnikovia lanata) a native shrub has superior forage quality for livestock and wildlife, and is important in the structure and the function of the Northern Mixed Prairie of North America. Seedbeds in the Northern Mixed Prairie are characterized by high fluctuations in temperature and soil water, especially at the soil surface during the spring under unpredictable weather conditions. High seedling mortality is a major limitation for establishing winterfat from direct seeding. Objectives of this study were to: 1) quantify germination responses to temperature and water potential; 2) predict seed germination and seedling emergence using constructed threshold models; and 3) investigate physiological mechanisms and the ecological relevance of model parameters. The constructed thermal and hydrothermal time models predicted germination time in most controlled temperature and water potential regimes with the modification of model assumptions in winterfat. For the first time, it was proved that winterfat seeds have a subzero base temperatures (Tb) for germination, achieving 43 to 67% germination at 3oC. The estimated Tb was lower in the large seeds (-4.5oC) than in the small seeds (-3.5oC) and the difference between seed collections was also about 1oC. Lower Tb favors large seeds to accumulate more thermal time at a given temperature, especially in early spring or fall when temperatures are low. Basic assumptions of hydrothermal time model, such as the constancy of model parameters, are invalid in winterfat. Model parameters varied with water potential, temperature and seed size within a seed collection. The predictability of constructed models is acceptable for seedling emergence only at optimal conditions in the field. Adverse seedbed conditions such as high soil temperatures (> 15oC) and limited soil water (< -0.5 MPa) reduced predictability of seedling emergence with the hydrothermal time model. Pre- and post-germination events that affect seed deterioration, seedling mortality and seedling elongation may reduce the predictability of the hydrothermal time model. Small seeds required approximately twice as long as large seeds to reach 50% germination at -1 to -3oC. Greater cold tolerance in large seeds was correlated with greater membrane integrity, less cold imbibition damage, higher contents of soluble cryoprotective sugars, such as glucose, raffinose and sucrose during germination at low temperature. These sugars prevent from dysfunctions of cell membrane and enzymes at freezing temperatures.