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- Creators: Arizona State University
Description
Many products undergo several stages of testing ranging from tests on individual components to end-item tests. Additionally, these products may be further "tested" via customer or field use. The later failure of a delivered product may in some cases be due to circumstances that have no correlation with the product's inherent quality. However, at times, there may be cues in the upstream test data that, if detected, could serve to predict the likelihood of downstream failure or performance degradation induced by product use or environmental stresses. This study explores the use of downstream factory test data or product field reliability data to infer data mining or pattern recognition criteria onto manufacturing process or upstream test data by means of support vector machines (SVM) in order to provide reliability prediction models. In concert with a risk/benefit analysis, these models can be utilized to drive improvement of the product or, at least, via screening to improve the reliability of the product delivered to the customer. Such models can be used to aid in reliability risk assessment based on detectable correlations between the product test performance and the sources of supply, test stands, or other factors related to product manufacture. As an enhancement to the usefulness of the SVM or hyperplane classifier within this context, L-moments and the Western Electric Company (WECO) Rules are used to augment or replace the native process or test data used as inputs to the classifier. As part of this research, a generalizable binary classification methodology was developed that can be used to design and implement predictors of end-item field failure or downstream product performance based on upstream test data that may be composed of single-parameter, time-series, or multivariate real-valued data. Additionally, the methodology provides input parameter weighting factors that have proved useful in failure analysis and root cause investigations as indicators of which of several upstream product parameters have the greater influence on the downstream failure outcomes.
ContributorsMosley, James (Author) / Morrell, Darryl (Committee member) / Cochran, Douglas (Committee member) / Papandreou-Suppappola, Antonia (Committee member) / Roberts, Chell (Committee member) / Spanias, Andreas (Committee member) / Arizona State University (Publisher)
Created2011
Description
A good production schedule in a semiconductor back-end facility is critical for the on time delivery of customer orders. Compared to the front-end process that is dominated by re-entrant product flows, the back-end process is linear and therefore more suitable for scheduling. However, the production scheduling of the back-end process is still very difficult due to the wide product mix, large number of parallel machines, product family related setups, machine-product qualification, and weekly demand consisting of thousands of lots. In this research, a novel mixed-integer-linear-programming (MILP) model is proposed for the batch production scheduling of a semiconductor back-end facility. In the MILP formulation, the manufacturing process is modeled as a flexible flow line with bottleneck stages, unrelated parallel machines, product family related sequence-independent setups, and product-machine qualification considerations. However, this MILP formulation is difficult to solve for real size problem instances. In a semiconductor back-end facility, production scheduling usually needs to be done every day while considering updated demand forecast for a medium term planning horizon. Due to the limitation on the solvable size of the MILP model, a deterministic scheduling system (DSS), consisting of an optimizer and a scheduler, is proposed to provide sub-optimal solutions in a short time for real size problem instances. The optimizer generates a tentative production plan. Then the scheduler sequences each lot on each individual machine according to the tentative production plan and scheduling rules. Customized factory rules and additional resource constraints are included in the DSS, such as preventive maintenance schedule, setup crew availability, and carrier limitations. Small problem instances are randomly generated to compare the performances of the MILP model and the deterministic scheduling system. Then experimental design is applied to understand the behavior of the DSS and identify the best configuration of the DSS under different demand scenarios. Product-machine qualification decisions have long-term and significant impact on production scheduling. A robust product-machine qualification matrix is critical for meeting demand when demand quantity or mix varies. In the second part of this research, a stochastic mixed integer programming model is proposed to balance the tradeoff between current machine qualification costs and future backorder costs with uncertain demand. The L-shaped method and acceleration techniques are proposed to solve the stochastic model. Computational results are provided to compare the performance of different solution methods.
ContributorsFu, Mengying (Author) / Askin, Ronald G. (Thesis advisor) / Zhang, Muhong (Thesis advisor) / Fowler, John W (Committee member) / Pan, Rong (Committee member) / Sen, Arunabha (Committee member) / Arizona State University (Publisher)
Created2011
Description
Federal education policies call for school district leaders to promote classroom technology integration to prepare students with 21st century skills. However, schools are struggling to integrate technology effectively, with students often reporting that they feel like they need to power down and step back in time technologically when they enter classrooms. The lack of meaningful technology use in classrooms indicates a need for increased teacher preparation. The purpose of this study was to investigate the impact a coaching model of professional development had on school administrators` abilities to increase middle school teachers` technology integration in their classrooms. This study attempted to coach administrators to develop and articulate a vision, cultivate a culture, and model instruction relative to the meaningful use of instructional technology. The study occurred in a middle school. Data for this case study were collected via administrator interviews, the Principal`s Computer Technology Survey, structured observations using the Higher Order Thinking, Engaged Learning, Authentic Learning, Technology Use protocol, field notes, the Technology Integration Matrix, teacher interviews, and a research log. Findings concluded that cultivating change in an organization is a complex process that requires commitment over an extended period of time. The meaningful use of instructional technology remained minimal at the school during fall 2010. My actions as a change agent informed the school`s administrators about the role meaningful use of technology can play in instruction. Limited professional development, administrative vision, and expectations minimized the teachers` meaningful use of instructional technology; competing priorities and limited time minimized the administrators` efforts to improve the meaningful use of instructional technology. Realizing that technology proficient teachers contribute to student success with technology, it may be wise for administrators to incorporate technology-enriched professional development and exercise their leadership abilities to promote meaningful technology use in classrooms.
ContributorsRobertson, Kristen (Author) / Moore, David (Thesis advisor) / Cheatham, Greg (Committee member) / Catalano, Ruth (Committee member) / Arizona State University (Publisher)
Created2011
Description
This study utilized symbolic interaction as a framework to examine the impact of mobility on four veteran elementary general music teachers' identities, roles, and perceptions of role support. Previous research has focused on teacher identity formation among preservice and novice teachers; veteran teachers are less frequently represented in the literature. Teacher mobility research has focused on student achievement, teachers' reasons for moving, and teacher attrition. The impact of mobility on veteran teachers' identities, roles, and perceptions of role support has yet to be considered. A multiple case design was employed for this study. The criteria for purposeful selection of the participants were elementary general music teachers who had taught for at least ten years, who had changed teaching contracts and taught in at least two different schools, and who were viewed as effective music educators by fine arts coordinators. Data were collected over a period of eight months through semi-structured interviews, email correspondence, observations, review of videotapes of the participants' teaching in previous schools, and collection of artifacts. Data were analyzed within and across cases. The cross-case analysis revealed themes within the categories of identity, role, and role support for the participants. The findings suggest that the participants perceived their music teacher roles as multi-dimensional. They claimed their core identities remained stable over time; however, shifts in teacher identity occurred throughout their years as teachers. The participants asserted that mobility at the start of their careers had a positive impact because they each were challenged to solidify their own teacher identities and music teacher roles in varied school contexts. Mobility negatively impacted role and teacher practices during times when the participants adjusted to new school climates and role expectations. Role support varied depending upon school context, and the participants discovered active involvement in the school community was an effective means of seeking and acquiring role support. Reflection experiences in music teacher preparation programs, as well as mentoring and professional development geared toward teacher identity formation and role maturation, may assist teachers in matching their desired school context with their teacher identities and perceptions of the music teacher role.
ContributorsGray, Lori F (Author) / Stauffer, Sandra (Committee member) / Schmidt, Margaret (Committee member) / Sullivan, Jill (Committee member) / Bush, Jeffrey (Committee member) / Tobias, Evan (Committee member) / Arizona State University (Publisher)
Created2011
Description
One of the critical imperatives for the development of inclusive school systems is the capacity to nurture and develop teachers who have the skills, critical sensibilities, and the contextual awareness to provide quality educational access, participation, and outcomes for all students; however, research on teacher learning for inclusive education has not yet generated a robust body of knowledge to understand how teachers become inclusive teachers in institutions where exclusion is historical and ubiquitous. Drawing from socio-cultural theory, this study aimed to fill this gap through an examination of teacher learning for inclusive education in an urban professional learning school. In particular, I aimed to answer the following two questions: (a) What social discourses are present in a professional learning school for inclusive education?, and (b) How do teachers appropriate these social discourses in situated practice? I used analytical tools from Critical Discourse Analysis (CDA) and Grounded Theory to analyze entry and exit interviews with teacher residents, principals, site professors, and video-stimulated interviews with teacher residents, observations of classroom practices and thesis seminars, and school documents. I found two social discourses that I called discourses of professionalism, as they offered teachers a particular combination of tools, aiming to universalize certain tools for doing and thinking that signaled what it meant to be a professional teacher in the participating schools. These were the Total Quality Management like discourse (TQM-like) and the Inclusive Education-like discourse. The former was dominant in the schools, whereas the latter was dominant in the university Master's program. These discourses overlapped in teachers' classrooms practices, creating tensions. To understand how these tensions were resolved, this study introduced the concept of curating, a kind of heuristic development that pertains particularly to the work achieved in boundary practices in which individuals must claim multiple memberships by appropriating the discourses and their particular tool kits of more than one community of practice. This study provides recommendations for future research and the engineering of professional development efforts for inclusive education.
ContributorsWaitoller, Federico R. (Author) / Artiles, Alfredo J. (Thesis advisor) / Kozleski, Elizabeth B. (Committee member) / Gee, James P (Committee member) / Arizona State University (Publisher)
Created2011
Description
Fiber-Wireless (FiWi) network is the future network configuration that uses optical fiber as backbone transmission media and enables wireless network for the end user. Our study focuses on the Dynamic Bandwidth Allocation (DBA) algorithm for EPON upstream transmission. DBA, if designed properly, can dramatically improve the packet transmission delay and overall bandwidth utilization. With new DBA components coming out in research, a comprehensive study of DBA is conducted in this thesis, adding in Double Phase Polling coupled with novel Limited with Share credits Excess distribution method. By conducting a series simulation of DBAs using different components, we found out that grant sizing has the strongest impact on average packet delay and grant scheduling also has a significant impact on the average packet delay; grant scheduling has the strongest impact on the stability limit or maximum achievable channel utilization. Whereas the grant sizing only has a modest impact on the stability limit; the SPD grant scheduling policy in the Double Phase Polling scheduling framework coupled with Limited with Share credits Excess distribution grant sizing produced both the lowest average packet delay and the highest stability limit.
ContributorsZhao, Du (Author) / Reisslein, Martin (Thesis advisor) / McGarry, Michael (Committee member) / Fowler, John (Committee member) / Arizona State University (Publisher)
Created2011
Description
The purpose of this practitioner inquiry was to explore the use of Guided Critical Reflection (GCR) in preparing preservice teachers for English learners (ELs). As a teacher researcher, I documented, analyzed, and discussed the ways in which students in my course used the process of GCR to transform their passively held understandings about ELs. Specifically, the research questions were: 1) What are preservice teachers' common sense about teaching and learning related to ELs? 2) How does GCR transform preservice teachers' common sense about ELs? 3) What is my role as an educator in creating opportunities for GCR? I utilized methods for data collection that fit my teaching practices. Data sources included three types of observations (self-reflective field notes, audio recordings of each class, and notes documented by an outside observer), student-work artifacts, and my audio reflection journal. I analyzed data inductively and deductively using a modified analytic induction approach. Building on previous research concerning the use of reflection in teacher preparation, I define GCR as the process in which I guided preservice teachers to acknowledge and examine their common sense about ELs, reframe what they know in light of course learning, and transform their understandings. Five major findings emerged from this study. First, preservice teachers entered the course with common sense notions about ELs rooted in their educational and life experiences. Students felt comfortable sharing what they knew about ELs, but needed to be scaffolded to examine how their life experiences shaped their common sense. Within the course, preservice teachers framed and reframed their common sense in different ways. Through the process of GCR, students evidenced a renewed sense about ELs. Finally, my role as a teacher involved establishing a comfortable learning environment, valuing my students' common sense as the catalyst for course learning, and guiding students through their reflective work. Ultimately, I was able to create opportunities for GCR because I too was reflecting on my practices, just as I was asking my students to reflect on their common sense about ELs.
ContributorsMarkos, Amy Michele (Author) / Arias, M. Beatriz (Thesis advisor) / Faltis, Christian (Committee member) / Hudelson, Sarah (Committee member) / Wiley, Terrence G. (Committee member) / Arizona State University (Publisher)
Created2011
Description
Nowadays ports play a critic role in the supply chains of contemporary companies and global commerce. Since the ports' operational effectiveness is critical on the development of competitive supply chains, their contribution to regional economies is essential. With the globalization of markets, the traffic of containers flowing through the different ports has increased significantly in the last decades. In order to attract additional container traffic and improve their comparative advantages over the competition, ports serving same hinterlands explore ways to improve their operations to become more attractive to shippers. This research explores the hypothesis that lowering the variability of the service time observed in the handling of containers, a port reduces the total logistics costs of their customers, increase its competiveness and that of their customers. This thesis proposes a methodology that allows the quantification of the variability existing in the services of a port derived from factors like inefficient internal operations, vessel congestion or external disruptions scenarios. It focuses on assessing the impact of this variability on the user's logistic costs. The methodology also allows a port to define competitive strategies that take into account its variability and that of competing ports. These competitive strategies are also translated into specific parameters that can be used to design and adjust internal operations. The methodology includes (1) a definition of a proper economic model to measure the logistic impact of port's variability, (2) a network analysis approach to the defined problem and (3) a systematic procedure to determine competitive service time parameters for a port. After the methodology is developed, a case study is presented where it is applied to the Port of Guaymas. This is done by finding service time parameters for this port that yield lower logistic costs than the observed in other competing ports.
ContributorsMeneses Preciado, Cesar (Author) / Villalobos, Jesus R (Thesis advisor) / Gel, Esma S (Committee member) / Maltz, Arnold B (Committee member) / Arizona State University (Publisher)
Created2011
Description
This qualitative study explores the learning experiences of two first-grade teachers in a progressive public elementary school in the southwestern U.S. Participants inquired into their literacy instruction practices within their reading-workshops. Weekly inquiry group conversations between teachers and researcher informed a perspective of learning as participation. During the semester-long study, two key questions guided design and implementation: 1) What is the nature of teachers' learning experiences related to their literacy instruction practices, contextualized within an inquiry group? 2) How do those learning experiences reflect and/or refract the community, interpersonal, and individual planes of analysis? An ethnographic perspective informed data collection and analysis; data were collected through weekly inquiry-group conversations, bi-weekly classroom observations, and in-depth interviews. A learning framework of community, interpersonal, and individual planes of analysis served as an analytic tool used in conjunction with a modified analytic induction. Teachers' case studies offer unique accounts of their learning, contextualized within their specific classrooms. Findings are discussed through narrative-based vignettes, which illustrate teachers' learning trajectories. On the community plane, apprenticeship relationships were evident in teachers' interactions with students' parents and with one another. Interpersonal interactions between teachers demonstrated patterns of participation wherein each tried to teach the other as they negotiated their professional identities. Analysis of the individual plane revealed that teachers' past experiences and personal identities contributed to ways of participation for both teachers that were highly personal and unique to each. Affective considerations in learning were a significant finding within this study, adding dimensionality to this particular sociocultural theory of learning. The ways teachers felt about themselves, their students, their community, and their work constituted a significant influence on what they said and did, as demonstrated on all three planes of analysis. Implications for practice include the significance of professional development efforts that begin at the site of teachers' questions, and attention to teachers' individual learning trajectories as a means to supporting educators to teach in more confident and connected ways.
ContributorsSteeg, Susanna Mae (Author) / Mccarty, Teresa L. (Thesis advisor) / Fischman, Gustavo E. (Committee member) / Marsh, Josephine P. (Committee member) / Smith, Karen (Committee member) / Arizona State University (Publisher)
Created2011
Description
This study examines teacher educators' understandings of hope related to teacher education. The study provides a previously unforeseen perspective on teacher educators' hope or lack of hope, and gives insight into that hope's foundation and maintenance. I have designed and implemented a rigorous multi-method study, beginning with developing and conducting a nationwide on-line survey with 625 participants. From a pool of 326 participants expressing interest in participating in interviews, I interviewed 23 teacher educators selected from a randomized and purposive sample. Finally, 25 participants took part in a writing prompt sent in lieu of an interview. Findings reflect that teacher educators' "hope" is a construct, a mixture of abstract ideas, emotions, dispositions, attitudes, that is hard to conceptualize or measure, but appears to be a very relevant and influential and hope for teacher educators takes place on a continuum from bystander to actualizing. The results of this study serve as a way to encourage educators to be more explicit about hope and discourses about teaching. It raises awareness about "false senses" of hope, which arise from narratives of redemption, paving the way for a conception of hope grounded in a strong understanding of the multiplicities of teaching, and how things "are." This conception of hope has the potential to foster discussions and actions of what education can be, rather than dwelling in the rhetoric of what education is not. Further, this research has the potential to open up spaces to discuss both the importance of and how to begin to think about incorporating hope into curricula through critical pedagogy and pedagogies of hope.
ContributorsRivers, Melissa Beth (Author) / Fischman, Gustavo E (Thesis advisor) / Christine, Carol J (Committee member) / De Barona, Maryann Santos (Committee member) / Barone, Thomas (Committee member) / Arizona State University (Publisher)
Created2011