Browsing by Subject "Data"
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Item Data use in an era of accountability : a case study of data driven decision making in high performing middle schools in the Rio Grande Valley(2011-05) Epp, Tracy Renee; Olivárez, Rubén; Barufaldi, James; Hollinger, Scott; Moll, Kerry; Saenz, VictorThis study examined how higher performing middle schools in the Rio Grande Valley use data to drive instructional decisions. Three research questions guided this study: (a) to what extent do higher performing, Title-1, middle schools in the Rio Grande Valley utilize data to make schoolwide instructional decisions; (b) how does the principal support data use for instructional decision-making; and (c) what do teachers perceive to be the processes that have led to the current level of data use in instructional decision making? A mixed-methods multiple-case study included middle schools that were drawn from a list of higher performing schools according to Just for the Kids and the National Center for Educational Achievement. To be included in the study, schools had to be located in the Rio Grande Valley, Texas, specifically in the counties of Starr, Cameron or Hidalgo. Additionally, the schools needed to be designated a Title-1 school, according to federal criteria. Data for the study was collected using a survey, followed by one-on-one interviews. Descriptive analyses was then conducted using the survey data. The interview data was analyzed using first-level coding followed by the use of cross case analysis to determine themes common to all cases. The findings from this research revealed that data is used extensively in the schools studied; primarily to determine the instructional scope of what is taught. It was found that while data use was extensive, the source and purpose of data use was limited to that which was directly tied to the state-administered assessment (TAKS). The second major finding was that principals create the necessary conditions for data use that becomes an embedded practice, where teachers can take risks with their colleagues in reviewing and using data. This study concludes that more principals can lead their schools to greater levels of data use by creating the necessary conditions for change. At the same time, the findings suggest that there is a need for leaders at all levels to examine and mitigate the unintended consequences of data use that is derived from a single-source and for a single purpose—that is, performance on the state exam (TAKS).Item Design of high speed low voltage data converters for UWB communication systems(Texas A&M University, 2006-08-16) Lee, Choong HoonFor A/D converters in ultra-wideband (UWB) communication systems, the flash A/D type is commonly used because of its fast speed and simple architecture. However, the number of comparators in a flash A/D converter exponentially increases with an increase in resolution; therefore, an interpolating technique is proposed in this thesis to mitigate the exponential increase of comparators in a flash converter. The proposed structure is designed to improve the system bandwidth degradation by replacing the buffers and resistors of a typical interpolating technique with a pair of transistors. This replacement mitigates the bandwidth degradation problem, which is the main drawback of a typical interpolating A/D converter. With the proposed 4-bit interpolating structure, 3.75 of effective number of bits (ENOB) and 31.52dB of spurious-free dynamic range (SFDR) are achieved at Nyquist frequency of 264MHz with 6.93mW of power consumption. In addition, a 4-bit D/A converter is also designed for the transmitter part of the UWB communication system. The proposed D/A converter is based on the charge division reference generator topology due to its full swing output range, which is attractive for low-voltage operation. To avoid the degradation of system bandwidth, resistors are replaced with capacitors in the charge division topology. With the proposed D/A converter, 0.26 LSB of DNL and 0.06 LSB of INL is obtained for the minimum input data stream width of 1.88ns. A 130 ??m ??286 ??m chip area is required for the proposed D/A converter with 19.04mW of power consumption. The proposed A/D and D/A converter are realized in a TSMC 0.18 ??m CMOS process with a 1.8 supply voltage for the 528MHz system frequency.Item The expanding role of community college trustees in student success(2013-05) Malcolm, Molly Beth; Cantú, Norma V., 1954-For generations American community colleges, governed by boards of trustees, have successfully provided open access to higher education. Today, all colleges are under intense pressure to improve student success rates. Using qualitative methodology, this grounded theory case study analyzed the expanding role of community college trustees in a college that has transformed to embrace student success. This study examined the expanding role of trustees through their eyes and the eyes of senior administrators. Their perceptions culminated into eight major themes: Achieving the Dream, Board of Trustees Institute, student success, data, leadership, partnership, trust, and vision. Two other themes of note developed: outcomes-based funding and the influence of Dr. Byron McClenney. Time expenditure on trustee duties and professional development concluded the findings. Conclusions drawn reveal that a transformational culture change from an emphasis solely on student access, to one of access plus student success began with the Board. Trustees developed an expanded skill set of awareness and acuity regarding student success data in order to interpret and use data effectively, resulting in an increased amount of time spent on Board duties and training. The Board now makes data driven decisions that have transformed fiscal policy to reflect the student success agenda. The primary focus of the Board is on how their actions affect student success rather than only on enrollment numbers and budgets. Through this process, the Trustees and Chancellor have developed a genuine and open partnership that extends to senior administrators. The Trustees continue to observe the boundaries of their policy-making roles as they ask the right questions without getting into day-to-day operations of the college. Because of limited research on community college trustees and student success, this study adds to available literature and may provide value to trustees, presidents, and chancellors who are changing their institutional culture to one focusing on student success. Conclusions drawn from the study may be used to enhance the education of trustees on their expanded role. The findings may also serve as a guide in helping trustees understand how to prioritize student success without stepping over the line into daily college operations.Item Information visualization : working with screens of experience(2012-05) Aler, Carolyn Jean; Lee, Gloria; Lee, Gloria; Shields, DavidInformation visualizations have become increasingly popular in the last decade. Viewing data visually has proved helpful in communicating or revealing information in many fields ranging from science to journalism to art. Information is incredibly malleable; given the same data, a group of designers may make wildly different information visualizations. The malleability of an information visualization leads me to believe that there are certain and finite truths in data, but when a designer converts data into information, they pass these truths through a screen of their experience. Additionally, a reader brings their own screen of experience, through which they read an information visualization. These screens of experience create infinite ways to communicate and interpret information. This report reviews some concepts and methods that I have found helpful when creating information visualizations.Item Investigation of Data Quality for Wind Tunnel Internal Balance Testing(2013-04-04) Hidore, John PrestonAchieving high quality, consistency, and testing efficiency in wind tunnel tests using internal balances is accomplished through the use of new testing methods, analysis of data output, and standardized documentation of test procedures at the Texas A&M Low Speed Wind Tunnel. The wind tunnel is capable of performing internal balance testing on models that experience less than 500 pounds of normal force. Testing has shown less than a 3% mean flow variation with the sting mount installed and a turbulence intensity of less than 0.25%. Documentation of procedures and check- lists for installation of internal balance testing equipment and test execution provide higher efficiency and consistency during a test. A step-by-step examination of the data analysis routines and associated uncertainty equations show uncertainty in the force and moment coefficients for the Mark XIII internal balance to be approximately ? 0.05 and ? 0.02, respectively. Quantifying the uncertainty of the primary output parameters and showing repeatability of the data within the defined uncertainty limits achieved higher quality results.Item The Long Tail of hydroinformatics : implementing biological and oceanographic information in hydrologic information systems(2012-12) Hersh, Eric Scott; Maidment, David R.; Bonner, Timothy; Dunton, Kenneth; Gilbert, Robert; Hodges, Ben; McKinney, DaeneHydrologic Information Systems (HIS) have emerged as a means to organize, share, and synthesize water data. This work extends current HIS capabilities by providing additional capacity and flexibility for marine physical and chemical observations data and for freshwater and marine biological observations data. These goals are accomplished in two broad and disparate case studies – an HIS implementation for the oceanographic domain as applied to the offshore environment of the Chukchi Sea, a region of the Alaskan Arctic, and a separate HIS implementation for the aquatic biology and environmental flows domains as applied to Texas rivers. These case studies led to the development of a new four-dimensional data cube to accommodate biological observations data with axes of space, time, species, and trait, a new data model for biological observations, an expanded ontology and data dictionary for biological taxa and traits, and an expanded chain-of-custody approach for improved data source tracking. A large number of small studies across a wide range of disciplines comprise the “Long Tail” of science. This work builds upon the successes of the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) by applying HIS technologies to two new Long Tail disciplines: aquatic biology and oceanography. In this regard this research improves our understanding of how to deal with collections of biological data stored alongside sensor-based physical data. Based on the results of these case studies, a common framework for water information management for terrestrial and marine systems has emerged which consists of Hydrologic Information Systems for observations data, Geographic Information Systems for geographic data, and Digital Libraries for documents and other digital assets. It is envisioned that the next generation of HIS will be comprised of these three components and will thus actually be a Water Information System of Systems.Item Optimization of vector quantization in Hybrid Vector Scalar Quantization (HVSQ)(2005-05) Varambally, Dheeraj B.; Mitra, Sunanda; Karp, Tanja; Krile, ThomasThe advancement in fields like multimedia, medical imagery and emergence of high resolution digital cameras has necessitated the acquisition, storage and transmission of high resolution digital images. Storage and transmission of such images are expensive in terms of bytes and bandwidth. There is a need for compressing these images to curtail the storage and transmission budget. A bewildering variety of image compression schemes featuring new concepts and techniques have been proposed to yield superior compression quality. Hybrid Vector Scalar Quantization (HVSQ) is one such novel compression scheme used for compressing high resolution cervigram image archives of the US National Library of Medicine. It is a lossy compression scheme comprising of two of the well known quantization techniques namely Vector and Scalar Quantization in the wavelet domain. This thesis focuses on implementation and optimization of the Vector Quantization module of HVSQ to yield higher image quality in terms of Peak Signal to Noise Ratio (PSNR) and lower encoding time. The thesis also focuses on evaluating the performance of Vector, Scalar and Hybrid Vector Scalar Quantization. The superior performance HVSQ is then verified by compressing a few high resolution natural images.Item Optimization of vector quantization in hybrid vector scalar quantization (HVSQ)(Texas Tech University, 2005-05) Varambally, Dheeraj B.; Mitra, Sunanda; Karp, Tanja; Krile, ThomasThe advancement in fields like multimedia, medical imagery and emergence of high resolution digital cameras has necessitated the acquisition, storage and transmission of high resolution digital images. Storage and transmission of such images are expensive in terms of bytes and bandwidth. There is a need for compressing these images to curtail the storage and transmission budget. A bewildering variety of image compression schemes featuring new concepts and techniques have been proposed to yield superior compression quality. Hybrid Vector Scalar Quantization (HVSQ) is one such novel compression scheme used for compressing high resolution cervigram image archives of the US National Library of Medicine. It is a lossy compression scheme comprising of two of the well known quantization techniques namely Vector and Scalar Quantization in the wavelet domain. This thesis focuses on implementation and optimization of the Vector Quantization module of HVSQ to yield higher image quality in terms of Peak Signal to Noise Ratio (PSNR) and lower encoding time. The thesis also focuses on evaluating the performance of Vector, Scalar and Hybrid Vector Scalar Quantization. The superior performance HVSQ is then verified by compressing a few high resolution natural images.Item Principals' leadership for learning : formative assessment strategies in every classroom(2013-12) Villalpando, Suzanne Martinez; Olivárez, RubénThe purpose of this study was to explore how school leaders address both the technical and professional socialization needs of teachers during the planning and implementation of student formative assessment in every classroom, an initiative that is often implemented as a means of gathering the data needed to support the academic needs of all learners (Black & Wiliam, 1998; Bolman & Deal, 2008; Heath & Heath, 2010; Leithwood & Seashore Louis, 2011; Wiliam, 2010). In order to determine school leadership considerations for addressing the technical and professional socialization needs of teachers during the implementation of student formative assessment in every classroom, two research questions guided the study: 1. What do teachers perceive to be their technical and professional socialization needs experienced during the planning and implementation of student formative assessment and how are these met? 2. What are the school principals’ perceptions of how they address the technical and professional socialization needs of teachers during the planning and implementation of student formative assessment? Using a grounded theory approach, this qualitative study examined the perceptions of both teachers and principals through a multi-site case study design (Miles & Huberman, 1994). This design was chosen in order to gather insight regarding the perceptions and experiences of principals and teachers at three elementary campuses that have implemented student formative assessment in every classroom. The sites and participants for this study were purposefully selected. Data were collected through interviews and focus groups. In order to confirm emerging theoretical explanations, the researcher gathered additional data through a review of relevant documents, such as district and campus improvement plans. The prominent technical needs identified by teachers in this study were the development of a campus-wide common terminology, participation in vertical teaming, and the maintenance of the support role of a campus instructional specialist. Furthermore, teacher participants identified their professional socialization needs as reassurance from the principal with new professional learning, a gradual pace of implementation for the student formative assessment initiatives, meaningful teacher-to-teacher interaction, open and transparent communication with the principal, and opportunities to participate in building cohesive grade-level teams. Principals perceived their technical supports as facilitating vertical teaming, providing a campus instructional specialist, embedding time for collaborative professional development, and setting clear expectations for implementation. Additionally, principals perceived their professional socialization supports for teachers as facilitating the building of cohesive grade-level teams, providing reassurance with new implementation, promoting open and transparent communication, promoting a gradual implementation pace and facilitating meaningful teacher-to-teacher interactions.Item Reliability and validity of the global physical activity questionnaire (GPAQ) and its utility: a review of the literature(2016-08) Matthews, Kristen Marie; Keating, Xiaofen; Castelli, DarlaObjective: To analyze the literature on the Global Physical Activity Questionnaire in regards to its reliability, validity, and utility. Methods: A review of the literature was performed in June 2016 using the following databases: PubMed and EBSCOhost Research Databases. Articles that analyzed the reliability and validity of the GPAQ internally, in comparison to other questionnaires, or in a country context were included. The following data were coded for each article: number of participants, mean age, validity measure(s), validity, and reliability. Frequency counts and mean values of reliability and validity were calculated. Results: Specific populations yielded different results in terms of the reliability and validity of the GPAQ. Overall, the GPAQ has been found to have similar, if not better, reliability and validity than other questionnaires that aim to measure physical activity, such as the International Physical Activity Questionnaire (IPAQ), Madras Diabetes Research Foundation- Physical Activity Questionnaire (MPAQ), Total Energy Expenditure Questionnaire (TEEQ), etc. Conclusions: The reliability and validity of the GPAQ are fairly acceptable in different populations. However, the GPAQ’s utility can be increased if its cultural relativity is improved throughout the world.Item Scalable algorithms for latent variable models in machine learning(2016-08) Yu, Hsiang-Fu; Dhillon, Inderjit S.; Pingali, Keshav; Qiu, Lili; Vishwananthan, S.V.N.; Lin, Chih-JenLatent variable modeling (LVM) is a popular approach in many machine learning applications, such as recommender systems and topic modeling, due to its ability to succinctly represent data, even in the presence of several missing entries. Existing learning methods for LVMs, while attractive, are infeasible for the large-scale datasets required in modern big data applications. In addition, such applications often come with various types of side information such as the text description of items and the social network among users in a recommender system. In this thesis, we present scalable learning algorithms for a wide range of latent variable models such as low-rank matrix factorization and latent Dirichlet allocation. We also develop simple but effective techniques to extend existing LVMs to exploit various types of side information and make better predictions in many machine learning applications such as recommender systems, multi-label learning, and high-dimensional time-series prediction. In addition, we also propose a novel approach for the maximum inner product search problem to accelerate the prediction phase of many latent variable models.Item Transport in higher dimensional phase spaces(2016-12) Curry, Christopher Timothy; Morrison, Philip J.; Horton, Jr., Claude W; Hazeltine, Richard; Matzner, Richard; Gamba, IreneWe use a four dimensional symplectic mapping, the coupled cubic-quadratic map, to provide evidence of Arnol’d Diffusion in phase space. We use the method of frequency analysis for dynamical systems to demonstrate the existence of regular orbits, and show that these orbits enclose weakly chaotic orbits which escape in finite time around the tori. A new collocation method for frequency analysis is employed by adapting it to allow for higher precision results. Arbitrary precision numerics are used to obtain highly accurate orbits for long timescales, and the adapted frequency method is used to obtain highly accurate frequencies of the mapping. We review the method of frequency analysis, demonstrate its effectiveness and accuracy in determining frequencies and finding tori in simple systems and low-dimensional mappings, and extend the results to higher dimensions. In the four dimensional mapping, we find several regular orbits with irrational frequency ratios, indicating the existence of tori in the phase space, as well as interior orbits that escape around these tori.